Abstract
A magnetic latch for fastening a closure member to a support. The magnetic latch comprises a latch bolt assembly comprising: a first elongated housing configured to be mounted with its rear side facing either the closure member or the support; a second housing connected to and positioned underneath the first housing, the second housing being rotatable with respect to the first housing around the vertical direction between a first rotational position in which the latch bolt assembly is operable for a right-handed closure member and a second rotational position in which the latch bolt assembly is operable for a left-handed closure member; and a latch bolt mounted in the second housing. The different rotational positions of the second housing allow using a horizontally moveable latch bolt while retaining a symmetrical placement on the closure system irrespective of the handedness of the closure member.
Claims
1. A magnetic latch for fastening a closure member to a support, the magnetic latch comprising a latch bolt assembly configured to be mounted to one of the closure member and the support and a keeper assembly configured to be mounted to the other one of the closure member and the support, the keeper assembly comprising a first magnetic element and the latch bolt assembly comprising: a first elongated housing extending along a vertical direction, the first housing having a front side and a rear side and being configured to be mounted with its rear side facing said one of the closure member and the support; a second housing connected to and positioned underneath the first housing, the second housing have a side face, wherein the second housing is rotatable with respect to the first housing around the vertical direction between a first rotational position in which the latch bolt assembly is operable for a right-handed closure member and a second rotational position in which the latch bolt assembly is operable for a left-handed closure member; a latch bolt mounted in the second housing and being moveable between a latching position and a retracted position along a horizontal direction, wherein the latch bolt in its latching position extends from the side face of the second housing, the latch bolt comprising a second magnetic element, wherein the first magnetic element and the second magnetic element are configured to magnetically attract each other to move the latch bolt into its latching position; and a latch bolt operating mechanism including an actuator mounted on top of the first housing, the latch bolt operating mechanism being configured to, upon actuation of the actuator, move the latch bolt from its latching position to its retracted position against the magnetic attraction between said first and said second magnetic element.
2. The magnetic latch according to claim 1, wherein one of the first housing and the second housing comprises a shaft extending in the vertical direction and having an end face, the other one of the first housing and the second housing comprising a corresponding hollow part which is rotatably mounted on the shaft.
3. The magnetic latch according to claim 2, wherein said corresponding hollow part comprises an inner collar having an abutment surface, the latch bolt assembly further comprising a fixation element mounted on the end face of the shaft and axially engaging the abutment surface in the vertical direction.
4. The magnetic latch according to claim 2, wherein the second housing comprises a further abutment surface, said hollow part comprising an end face which axially engages the further abutment surface.
5. The magnetic latch according to claim 1, wherein one of the first housing and the second housing comprises a first stop and a second stop, the other one of the first housing and the second housing comprising a protrusion which engages the first stop when the second housing is in its first rotational position and which engages the second stop when the second housing is in its second rotational position.
6. The magnetic latch according to claim 1, wherein the second housing comprises two opposing sides adjacent the side face, the two opposing sides being symmetrical to one another.
7. The magnetic latch according to claim 6, wherein each of said opposing sides comprises identical coupling means.
8. The magnetic latch according to claim 7, wherein the latch bolt assembly further comprises a stop mounted, using the coupling means, to a first one of said two opposing sides when the second housing is in its first rotational position and to a second one of said two opposing sides when the second housing is in its second rotational position.
9. The magnetic latch according to claim 7, wherein further coupling means are provided on the rear side of the first housing, which further coupling means are continuous with said coupling means on the opposing sides of the second housing.
10. The magnetic latch according to claim 9, wherein the further coupling means comprise a guide configured to be mounted on a corresponding mounting element on said one of the closure member and the support.
11. The magnetic latch according to claim 7, wherein the coupling means comprise a guide configured to be mounted on a corresponding mounting element on said one of the closure member and the support.
12. The magnetic latch according to claim 1, wherein the latch assembly further comprises a releasable fixation member to fix the second housing to the first housing in either one of its first and its second rotational position.
13. The magnetic latch according to claim 1, wherein the second housing is rotatable with respect to the first housing around the vertical direction between the first rotational position and the second rotational position over an angle comprised between 140° and 220° and particularly between 170° and 190°, which angle is most particularly about 180°.
14. The magnetic latch according to claim 1, wherein the latch bolt operating mechanism comprises: a vertically extending link rod mounted in the first housing and having a lower end, the vertically extending link rod being slideable in the vertical direction from a rest position to an actuated position upon actuation of the actuator; a sliding cam connected to the lower end of the link rod and being moveable by a translational motion in a vertical direction from a first position to a second position; and a follower lever pivotally connected to the second housing and connected to the latch bolt, the sliding cam engaging the follower lever to move the follower lever from a rest position to an actuated position upon actuation of the actuator thereby sliding the latch bolt from its latching position to its retracted position, wherein the sliding cam is rotatable with respect to the link rod around the vertical direction, in particular over an angle comprised between 140° and 220° and more particularly between 170° and 190°, which angle is most particularly about 180°.
15. The magnetic latch according to claim 1, wherein the latch bolt assembly comprises a latch bolt biasing member arranged to urge the latch bolt into its retracted position.
16. A method of mounting the latch bolt assembly of the magnetic latch according to claim 1 onto one of the closure member and the support, the method comprising: rotating the second housing into one of its first and its second rotational position; fixing the second housing in said one of its first and its second rotational position, in particular by fastening a releasable fixation member; and mounting the first elongated housing and/or the second housing to said one of the closure member and the support.
17. The method of claim 16, wherein the method further comprises fixing a stop to the front side of the second housing.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0112] The invention will be further explained by means of the following description and the appended figures.
[0113] FIG. 1 shows a perspective view of an embodiment of a magnetic latch assembly mounted on a closure system.
[0114] FIG. 2 shows a perspective view of the latch bolt assembly and the magnetic keeper assembly that form the magnetic latch assembly of FIG. 1.
[0115] FIG. 3A shows a front view of the latch bolt assembly of FIG. 2 with the housing having been removed and with the latch bolt in its latched state.
[0116] FIG. 3B shows a cross-section through the latch bolt assembly along plane ‘A’ indicated in FIG. 3A.
[0117] FIG. 4A shows a front view of the latch bolt assembly of FIG. 2 with the housing having been removed and with the latch bolt in its retracted state and the knob in its actuated position.
[0118] FIG. 4B shows a cross-section through the latch bolt assembly along plane ‘A’ indicated in FIG. 4A.
[0119] FIG. 5A shows a front view of the latch bolt assembly of FIG. 2 with the housing having been removed and with the latch bolt in its retracted state and the knob in its rest position.
[0120] FIG. 5B shows a cross-section through the latch bolt assembly along plane ‘A’ indicated in FIG. 5A.
[0121] FIG. 6 shows a perspective, partially exploded, view of the top part of the latch bolt assembly of FIG. 2 with the housing having been removed and with the knob in its rest position.
[0122] FIG. 7A shows a perspective view of the top part of the latch bolt assembly of FIG. 2 with the housing having been removed, with the locking mechanism in its unlocking position and with the knob in its rest position.
[0123] FIG. 7B shows a similar view as FIG. 7A but with the locking mechanism in its locking position and with the knob between its actuated and its rest position.
[0124] FIG. 7C shows a similar view as FIG. 7B but with the locking mechanism in its locking position and with the knob in its rest position.
[0125] FIGS. 8A to 8C show the same configuration as FIGS. 7A to 7C with a front view.
[0126] FIG. 9A shows an exploded view of the magnetic keeper assembly of FIG. 2.
[0127] FIG. 9B shows a top view of the magnetic keeper assembly of FIG. 2.
[0128] FIG. 9C shows a rear side view of the magnetic keeper assembly of FIG. 2.
[0129] FIG. 10 shows a front view of the pawl locking member.
[0130] FIGS. 11A and 11B show a perspective view of an embodiment of a magnetic latch assembly mounted on a right-handed, respectively left-handed, closure system.
[0131] FIGS. 12A and 12B show a perspective view of mounting the latch bolt assembly of the magnetic latch assembly of FIGS. 11A and 11B on a right-handed, respectively left-handed, hinged closure member.
[0132] FIG. 13A shows a cross-section through the bottom mounting bracket and partially through the bottom part of the latch bolt assembly of the magnetic latch assembly of FIGS. 11A and 11B illustrating the height adjustment mechanism.
[0133] FIG. 13B shows a cross-section through an alternative mounting bracket for mounting the latch bolt assembly of the magnetic latch assembly of FIGS. 11A and 11B.
[0134] FIG. 14A shows a longitudinal cross-section through the bottom part of the latch bolt assembly of the magnetic latch assembly of FIGS. 11A and 11B in its latching position.
[0135] FIG. 14B shows a similar view as FIG. 14A with the knob in its actuated position.
[0136] FIG. 14C shows a similar view as FIG. 14A with the knob in its rest position and with the latch bolt in its retracted position.
[0137] FIG. 15 shows a horizontal cross-section through the latch bolt assembly of FIGS. 11A and 11B.
[0138] FIGS. 16A and 16B show a partially exploded view of the latch bolt assembly of FIGS. 11A and 11B.
[0139] FIGS. 17A and 17B show a transverse cross-sectional view through the latch bolt assembly of FIGS. 11A and 11B.
[0140] FIG. 18 shows a perspective view of the puller and part of the lower link rod of the latch bolt assembly of FIGS. 11A and 11B.
[0141] FIG. 19 shows an exploded view of the bottom mounting bracket used in the height adjustment mechanism.
[0142] FIG. 20 shows a longitudinal cross-section through part of the latch bolt assembly of FIGS. 11A and 11B.
[0143] FIGS. 21A to 21C show a longitudinal cross-section through a magnetic latch assembly in its latching, unlatched, and rest position.
DESCRIPTION OF THE INVENTION
[0144] The present invention will be described with respect to particular embodiments and with reference to certain drawings but the invention is not limited thereto but only by the claims. The drawings described are only schematic and are non-limiting. In the drawings, the size of some of the elements may be exaggerated and not drawn on scale for illustrative purposes. The dimensions and the relative dimensions do not necessarily correspond to actual reductions to practice of the invention.
[0145] Furthermore, the terms first, second, third and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequential or chronological order. The terms are interchangeable under appropriate circumstances and the embodiments of the invention can operate in other sequences than described or illustrated herein.
[0146] Moreover, the various embodiments, although referred to as “preferred” are to be construed as exemplary manners in which the invention may be implemented rather than as limiting the scope of the invention.
[0147] FIG. 1 shows a perspective view of a first embodiment of a magnetic latch assembly 1 mounted on a closure system. The closure system comprises a closure member 2 that is hinged on a first support 3 and that may be fastened to a second support 4 by means of the magnetic latch assembly 1. In the illustrated embodiment, the closure member 2 is formed by a gate and the supports 3, 4 are formed by fixed posts, but it will be readily appreciated that the magnetic latch assembly 1 is also suitable for other kinds of closure members (e.g. a sliding closure member, a door, etc.) and/or supports. For example, the support may be formed by a closure member in case the magnetic latch assembly 1 is used on a double gate.
[0148] The magnetic latch assembly 1 generally comprises a latch bolt assembly 5 and a magnetic keeper assembly 6 as shown in FIG. 2. In the illustrated embodiment, the latch bolt assembly 5 is mounted on the support 4 and the magnetic keeper assembly 6 is mounted on the closure member 2, but it will be readily appreciated that these may be reversed. As shown in FIG. 2, the latch bolt assembly 5 comprises a vertically oriented elongated housing 7 with a pull knob 8 protruding from the top thereof. The housing 7 is mounted on the closure member 2 using two L-shaped mounting brackets 9. Preferably, the height of the housing 7 with respect to the mounting brackets 9 is adjustable in order to vertically align the latch bolt assembly 5 mounted on the support 4 to the magnetic keeper assembly 6 mounted on the closure member 2. At the bottom of the housing 7, there is provided an L-shaped bracket 10 having one leg 11 fastened to the bottom of the housing using screws 12 (see FIG. 3A) and a second leg 13 which is located opposite the magnetic keeper assembly 6 and to which the bottom L-shaped mounting bracket 9 is fastened. The L-shaped bracket 10 is open at both sides in order to engage with the magnetic keeper assembly 6 on either side such that the latch bolt assembly 5 is operable for both right-handed and left-handed closure members 2 without any modifications. It will be readily appreciated that the elongated housing 7 may be regarded as a frame on which the various components of the latch bolt assembly are mounted. The operation of the latch bolt assembly 5 will be described in more detail by reference to FIGS. 3A to 8C. The magnetic keeper assembly 6 will be described in more detail by reference to FIGS. 9A to 9C.
[0149] FIGS. 3A and 3B show the latch bolt assembly 5 in its latched position, i.e. where the closure member 2 is fastened to the support 4. The latch bolt assembly 5 comprises a latch bolt 14 at its bottom. More specifically, the latch bolt 14 extends through the first leg 11 of the L-shaped bracket 10 and is moveable in the vertical direction 15 between an extended position (shown in FIGS. 3A and 3B) and a retracted position (shown in FIGS. 4A to 5B). The latch bolt 14, at its upper end 14a, is fixedly connected to a slideable coupler 15, in particular to the lower end 16A thereof, in particular by a transversely positioned pin 16. More specifically, the latch bolt 14 is provided with a circumferential groove (best shown in FIG. 3A) and the transversely positioned pin 16 (e.g. a rivet) partially engages part of this circumferential groove. A latch bolt spring 17 is positioned between the coupler 15 and the top side of the L-shaped bracket 10. In the illustrated embodiment, the latch bolt spring 17 is a compression spring which urges the upper end of the latch bolt 14 upwards, i.e. away from the top side of the L-shaped bracket 10. As such, the latch bolt 14 is urged by the latch bolt spring 17 towards the retracted position.
[0150] The magnetic keeper assembly 6 is shown in an exploded view in FIG. 9A and comprises a keep 18 which houses a magnet 19, in particular a permanent magnet, although it will be readily appreciated that an electromagnet is also feasible. The keep 18 has an elongated part 20 on its side in order to allow the keep 18 to be mounted on the closure member 2 by means of an L-shaped mounting bracket 21. More specifically, the L-shaped mounting bracket 21 is mounted to the closure member 2 and a horizontal guide 22 is mounted directly on the L-shaped mounting bracket 21 (and fixed thereto by means of screw 30) with the elongated part 20 of the keep 18 being mounted on the horizontal guide 22. A setting screw 23 and corresponding setting nut 24 are provided in order to horizontally adjust the position between the keep 18 and the horizontal guide 22. More specifically, the setting nut 24 is positioned on one side within a corresponding hole 27 on the horizontal guide and with the other side in a horizontal groove 28 in the elongated part 20. The setting nut 24 is provided with an internal screw thread corresponding to that of the setting screw 23. A rotation of the setting screw 23 causes the setting nut 24 to slide along the length of the setting screw 23 (as best shown in FIG. 9C) thus causing the keep 18 to slide horizontally with respect to the horizontal guide 22 that is fixedly positioned on the closure member 2. This allows to correctly position the keep 18, in particular the latch bolt receiving area 29, with respect to the latch bolt assembly 5 mounted on the support 4. A curved washer 25 may be provided between the setting screw 23 and the setting nut 24. A cover 26 is provided in order to finish the magnetic keeper assembly 6.
[0151] When the closure member 2 is closed (as illustrated in FIG. 1), the magnet 19 provided in the magnetic keeper assembly 6 exerts a force on the latch bolt 14 thereby attracting the latch bolt 14 against the force of the latch bolt spring 17 to its latching position. As such, the latch bolt 14 is manufactured from a ferromagnetic material, preferably iron. When the latch bolt 14 is in its latching position, it, in particular its lower end 14b, is kept by the keep 18, in particular in the latch bolt receiving area 29, the magnetic keeper assembly 6 in order to fasten the closure member 2 to the support 4. More specifically, when the latch bolt 14 is in its latched position in the keeper 18, the bottom part of the latch bolt 14, when attempting to open the closure member 2, pushes against the bounding wall 31 of the latch bolt receiving area 29.
[0152] The latch bolt assembly 5 is generally provided with a latch bolt operating mechanism which allows to retract the latch bolt 14 against the force of the magnet 19 in order to unfasten the closure member 2 with respect to the support 4. In the illustrated embodiment, the latch bolt operating mechanism comprises a frame 32 that is fixed to the housing 7, the knob 8 at the top of the housing 7, an upper link rod 33 connected to a lower link rod 34 by a lever 35.
[0153] The upper link rod 33 comprises a top part 36 and a bottom part 37 connected by a horizontal plate 39 such that these parts 36, 37 are located in a different position when viewed in the depth direction 38 (see FIG. 3B) of the latch bolt assembly 5. The reasons as to why the upper link rod 33 is so split will be described below with reference to FIGS. 6 to 8C. The top part 36 of the upper link rod 33 has an upper end 36a on which the knob 8 is fixed and a lower end 36b that is fixed on the horizontal plate 39. The bottom part 37 of the upper link rod 33 has an upper end 37a that is fixed on the horizontal plate 39 and a lower end 37b that is connected to the lever 35.
[0154] In the illustrated embodiment, the knob 8 is fixed to the upper end 36a of the upper link rod 33 by an angular snap-fit joint. The angular snap-fit joint is best shown in FIG. 3B. The angular snap-fit joint comprises a chamber within the knob 8, which chamber has a larger cross-section at the top and a smaller cross-section at the bottom. The upper end 36a of the upper link rod 33 has a corresponding locally thicker part. When assembling the latch bolt assembly 5, the knob 8 is slid onto the upper link rod 33 of which the thicker top part is compressed and the re-expands to fill the chamber. This provides a robust connection which is moreover invisible from the outside of the magnetic latch 1. In the illustrated embodiment, the knob 8 is made from metal, while the upper link rod 33 is made from a plastic material.
[0155] The lever 35 has a first end 35a, a central part 35b, and a second end 35c. The lower end 37b of the bottom part 37 of the upper link rod 33 is connected to the first end 35a of the lever 35 by means of a pin 40 transversely placed extending through openings (not shown) in the lower end 37b of the bottom part 37 of the upper link rod 33 and the first end 35a of the lever 35. The frame 32 has a vertically oriented protrusion 41 which has a upper end 41a fixed to the frame 32 and a lower end 41b which is connected to the second end 35c of the lever 35 by means of a pin 42 transversely placed extending through an opening (not shown) in the lower end 41b of the protrusion 41 and through an elongated opening 43 in the second end 35c of the lever 35. The central part 35b of the lever 35 also has an elongated opening 44 used for connecting the upper end 34a of the lower link rod 34 to the lever 35 by means of a pin 45 transversely placed extending through an opening (not shown) in the upper end 34a of the lower link rod 34 and through the elongated opening 44.
[0156] The lever 35 is rotatable about its second end 35c between a rest position (shown in FIGS. 3A, 3B, 5A and 5B) and an actuated position (shown in FIGS. 4A and 4B). More specifically, the first end 35a of the lever 35 is able to rotate, in particular over an angle of about 90°, with respect to the transverse pin 42 around the width direction 46 (indicated in FIG. 3A). The elongated openings 43, 44 allow the upper link bar 33 and the lower link bar 34 to remain vertically oriented during the rotation of the lever 35 as the lever 35 can slide in the depth direction 38 with respect to the lower end 37b of the upper link bar 33 and the upper end 34a of the lower link bar 34, which sliding motion would not be possible in case the openings 43, 44 were circular.
[0157] The lower link rod 34 has a lower end 34b that engages the slideable coupler 15. More specifically, the upper end 16B of the coupler 15 has an opening (not shown) through which the lower link rod 34 extends. The lower end 34b of the lower link rod 34 is so shaped that it cannot pass through the opening in the upper end 16B of the coupler 15 as best in FIG. 3B. The coupler 15 has a vertically oriented groove 47 and the lower end 34b is guided in this groove 47. The coupler 15 is slideable between a lower position (shown in FIGS. 3A and 3B) and an upper position (shows in FIGS. 4A to 5B). The lower position of the coupler 15 corresponds to the latched position of the latch bolt 14 and the upper position of the coupler 15 corresponds to the retracted position of the latch bolt 14 because the upper end 14a of the latch bolt 14 is fixed to the lower end 16A of the coupler 15 as described above. The coupler 15 further has an opening 48 adjacent the groove 47, which opening 48 allows to place the coupler 15 on the lower end 34b of the lower link rod 34.
[0158] The latch bolt assembly 5 operates in the following way. FIGS. 3A and 3B show the latch bolt 14 in its latching position due to the magnetic attraction from the magnet 19 in the magnetic keep assembly 6. When a user desires to open the closure member 2, the user pulls the knob 8 upwards from its rest position to its actuated position as shown in FIGS. 4A and 4B. The upwards movement of the knob 8 causes the upper link rod 33 to move upwards (i.e. the upper link rod 33 undergoes an upwards translational motion) thereby rotating the first end 35a of the lever 35 in a first rotational direction 49 and pulling the lower link rod 34 upwards (i.e. the lower link rod 34 undergoes an upwards translational motion). Because the lower end 34b of the lower link rod 34 is abutting the upper end 16B of the coupler 15, the coupler 15 is pulled upwards which in turn pulls latch bolt 14 upwards to its retracted position (i.e. the latch bolt 14 and the coupler 15 undergo an upwards translational motion). Once the latch bolt 14 is in its retracted position, the closure member 2 is unfasted and the user may open the closure member 2 and the knob 8 may be let go. Gravity will cause the knob 8 to fall downwards to its rest position as shown in FIGS. 5A and 5B. The downwards movement of the knob 8 causes the upper link rod 33 to move downwards (i.e. the upper link rod 33 undergoes a downwards translational motion) thereby rotating the first end 35a of the lever 35 in a second rotational direction 50 (which is opposite to the first rotational direction 49) and pushing the lower link rod 34 downwards (i.e. the lower link rod 34 undergoes a downwards translational motion). Since the lower end 34b of the lower link rod 34 is free to slide within the groove 47 in the coupler 15, the coupler 15 is not affected by the motion of the lower link rod 34. Rather, the coupler 15 remains in its upper position due to the latch bolt spring 17 thus keeping the latch bolt 14 in its retracted state. When the closure member 2 is again closed (either due to the user or due to the provision of self-closing means, e.g. a self-closing hinge), the magnet 19 again attracts the latch bolt 14 thus pulling the latch bolt 14 and the coupler 15 downwards (i.e. the latch bolt 14 and the coupler 15 undergo a downwards translational motion) against the latch bolt spring 17 to the configuration shown in FIGS. 3A and 3B.
[0159] The force required to unfasten the closure member 2 is effectively determined by the magnetic field strength H of the magnet 19, the shape of the latch bolt 14 and the configuration of the lever 35. Increasing the magnetic field strength H increases the force exerted on the latch bolt 14. A likewise effect may be achieved by increasing the volume of the latch bolt 14 as this also increases the magnet force exerted thereon. However, this results in a bulkier latch bolt assembly 5 which is undesired. A higher attraction force is beneficial as this allows to attract the latch bolt 14 from greater distances thus allowing more leeway between the support 4 and the closure member 2. However, a downside of a higher attraction force is that the user has to exert a higher force on the knob 8 in order to retract the latch bolt 14. The lever 35 alleviates this effect since it causes a force reduction between the lower link rod 34 and the upper link rod 33. In other words, the lever 35 is a second-order lever with the upper link 33 being the effort and the lower link 34 being the load and the transverse pin 42 forming the fulcrum.
[0160] In the illustrated embodiment, the magnet 19 is a neodymium magnet with 22 kg of retaining force and a height and diameter of 25 mm. The magnet 19 exerts an attraction force on the latch bolt 14 (which latch bolt 14 has a diameter of 12 mm in the illustrated embodiment, but other diameters are possible) between 65 and 70 N and the lever 35 reduces the force such that the knob 8 can be lifted by applying a pulling force between 30 and 40 N. However, other force values are also possible. In general, the force required to pull the knob 8 is between 15 and 60 N, preferably between 20 and 50 N, and more preferably between 25 and 45 N. The magnetic attraction force exerted on the latch bolt 14 is preferably as large as possible and may generally be between 40 and 150 N, preferably between 50 and 100 N and more preferably between 60 and 90 N. This allows to attract the latch bolt 14 from distances exceeding 10 mm thus allowing more leeway between the support 4 and the closure member 2.
[0161] The latch bolt assembly 5 is also provided with a key cylinder 51 that allows to lock the closure member 2 in its fastened position with respect to the support 4. In other words, the key cylinder 51 is part of a locking mechanism that prohibits movement operation of the latch bolt operating mechanism. The locking mechanism will be described with respect to FIGS. 6 to 8C. The key cylinder 51 is a Euro-cylinder corresponding to standard DIN 18252/2006 (as shown in FIGS. 3B, 4B and 5B) which may be operated from either side of the closure member 2 and has a single rotary driving bit 52 centrally positioned with respect to the key cylinder 52. However, other kinds of key cylinder 51 (e.g. a key-in-knob cylinder) are known to the skilled person and may also be used in the latch bolt assembly.
[0162] The key cylinder 51 is fixed to the frame 32 by a transversely positioned bolt 103 shown in FIGS. 8A to 8C. The key cylinder 51 is placed centrally with respect to the housing 7 of the latch bolt assembly 5. This central placement is possible due to the specific shape of the upper link rod 33. More specifically, the bottom part 37 of the upper link rod 33 has two parallel legs 37c, 37d with a groove 53 provided therebetween. The key cylinder 51 extends through this groove 53 and the groove 53 is substantially elongated to allow the bottom part 37 of the upper link rod 33 to slide with respect to the frame 32 as required for the normal operation of the latch bolt operating mechanism described above. Furthermore, the bottom part 37 of the upper link rod 33 is positioned more closely to the frame 32 with respect to the top part 36 of the upper link rod 33. This provides the required space for the rotary driving bit 52 of the key cylinder 51 which may freely rotate adjacent to the bottom part 37 of the upper link rod 33. An alternative would be to make the groove 37 wider to allow a rotation of the rotary driving bit 52. In this way, the top part 36 and the bottom part 37 of the upper link rod 33 may be placed in the same plane, however this increases the width of the latch bolt assembly 5, meaning that the latch bolt assembly 5 is quite bulky and has to be wider than the support 4 which is undesired.
[0163] The locking mechanism comprises a pawl locking member 54 that is mounted on the frame 32 by a transverse pin 55 that is placed through an opening 56 in the frame 32, an opening 57 in the pawl locking member 54 and into a hole (not shown) provided in the frame 32. The pin 55 forms a pivot around which the pawl locking member 54 is rotatable between a first position (shown in FIGS. 7A and 8A) and a second position (shown in FIGS. 7B, 7C, 8B and 8C). The pawl locking member 54 is guided between its two positions by means of a curved slot 66 and a cooperating pin 67 (shown in FIG. 8B). The pin 67 is fixed to the frame 32 and movement of the pawl locking member 54 beyond its two positions is prevented as the pin 67 engages the ends of the slot 66. The bottom part of the pawl locking member 54 has a groove 58 formed by two sidewalls 58a, 58b in a shape corresponding to that of the rotary driving bit 52.
[0164] The shape of the slot 66 is best illustrated in FIG. 10 which shows a front view of the pawl locking member 54. The groove 66 has a specific shape with a narrower central part 113 and larger (compared to the central part 113) end regions 111, 112. The narrower central part 113 is caused by inwardly positioned ridges 114, 115. Besides these ridges 114, 115, there is provided a groove or opening 116, 117 in the pawl locking member 54. More generally, the groove or opening 116, 117 may be formed by a local weakening of the pawl locking member 54 in order to allow the ridges 114, 115 to be displaced outwards due to the pin 67 moving between the end regions 111, 112 upon actuation of the key cylinder 51. The ridges 114, 115 are resilient and urge the pin 67 to either one of the end regions 111, 112. As such, the specific shape forms a bi-stable pawl locking member 54.
[0165] The locking mechanism further comprises a pawl 59 that is mounted on the pawl locking member 54. More specifically, the pawl 59 has an opening 60 with the pin 55 also being placed through this opening 60 to mount the pawl 59 to the pawl locking member 54 and the frame 32. The pin 55 thus also forms a pivot around which the pawl 59 is able to rotate between a rest position with respect to the pawl locking member 54 (shown in FIGS. 7A, 7C, 8A and 8C) and a displaced position with respect to the pawl locking member 54 (shown in FIGS. 7B and 8B). The pawl locking member 54 is provided with an abutment 62 which defines the rest position of the pawl 59, i.e. in the rest position the pawl 59 abuts against the abutment 62 provided on the pawl locking member 54. A spring 61 is disposed between the pawl locking member 54 and the pawl 59 in order to urge the pawl 59 into its rest position with respect to the pawl locking member 54, i.e. pushing the pawl 59 against the abutment 62. The spring 61 is a torsion spring having a first end 61a that engages the pawl locking member 54 and a second end 61b that engages the pawl 59. The pawl 59 further comprises an abutment surface 63 against which the top surface 64 of the horizontal plate 39 (which is part of the upper link rod 33) may abut.
[0166] The locking mechanism operates in the following way. When the key cylinder 51 is unlocked (as shown in FIGS. 7A and 8A), the pawl 59 is in its rest position with respect to the pawl locking member 54 which itself is located in its first position. The abutment surface 63 of the pawl 59 is positioned next to the top surface 64 of the horizontal plate 39 which is part of the upper link rod 33. As such, the pawl 59 is in its retracted position and normal operation (i.e. an upwards translation upon pulling the knob 8) of the upper link member 33 is possible as shown in FIGS. 7A and 8A. For this reason, the first position of the pawl locking member 54 is also referred to as the locking position since the pawl 59 is locked in its retracted position with respect to the upper link member 33 and normal operation is allowed. Actuating the key cylinder 51 causes a rotation of the rotary driving bit 52 in a locking direction 65 (indicated in FIG. 8A) and causes the pawl locking member 54 to be rotated towards its second position. The pawl 59 remains stationary with respect to the pawl locking member 54 and thus remains in its rest position. The abutment surface 63 of the pawl 59 is positioned above the top surface 64 of the horizontal plate 39 which is part of the upper link rod 33. As such, the pawl 59 is in its extended position and normal operation (i.e. an upwards translation upon pulling the knob 8) of the upper link member 33 is prevented as shown in FIGS. 7C and 8C. Actuating the key cylinder 51 causes a rotation of the rotary driving bit 52 in a unlocking direction 68 (indicated in FIG. 8C) and causes the pawl locking member 54 to be rotated towards its first position shown in FIG. 8A thereby again allowing normal operation.
[0167] The main advantage of the pawl 59 and the pawl locking member 54 is to avoid blocking the knob 8 in the actuated (i.e. upwards) position when the key cylinder 51 is actuated while the knob 8 is kept upwards by the user as illustrated in FIGS. 7B and 8B. More specifically, in case the knob 8 is pulled upwards (i.e. the upper link rod 33 is in an upwards position) and the key cylinder 51 is actuated to move the pawl locking member 54 to its second position, a pawl that is fixed on the pawl locking member 54 would prevent the knob 8 being pulled downwards by gravity to its rest position. However, as the pawl 59 is rotatable with respect to the pawl locking member 54, the downwards motion of the knob 8 and the upper link rod 33 (i.e. the horizontal plate 39) pushes the pawl 59 (in particular against the side surface 102 of the pawl 59) to the side (i.e. against the spring 61). Once the horizontal plate 39 has passed the pawl 59, the spring 61 pushes the pawl 59 against the abutment surface 62 on the pawl locking member 54 to its locking position illustrated in FIGS. 7C and 8C. For this reason, the second position of the pawl locking member 54 is also referred to as the release position since the pawl 59 is released and is free to be moved from its extended to its retracted position by the downwards motion of the knob 8.
[0168] It will be appreciated that variations of the construction of the pawl 59 and/or the pawl locking member 54 are possible. For example, the spring 61 may be interposed between the pawl 59 and the frame 62, the pawl 59 and/or the pawl locking member 54 may undergo a translational motion instead of a rotary motion, the pawl 59 and the pawl locking member 54 may be mounted on different rotational axes, the pawl 59 may engage another part of the upper link rod 33, etc.
[0169] It will be readily appreciated that various modifications are possible in which the advantages of the second-order lever between the link rods 33, 34 and/or of the locking mechanism are also obtained. For example, in an embodiment, the magnetic roles of the latch bolt 14 and the magnet 19 are reversed. In other words, the latch bolt 14 is a permanent magnet and element 19 is made from a ferromagnetic material (e.g. iron). The operation of the magnetic latch assembly 1 remains unaffected because the latch bolt 14 will still be attracted to the element 19 as this is fixedly positioned within the keeper assembly 6. Moreover, it is also possible that the latch bolt 14 and the magnet 19 are permanent magnets and/or electromagnets. In another embodiment, the latch bolt 14, coupler 15 and latch bolt spring 17 are replaced by a magnetic element fixed to the lower end 34a of the lower link rod 34. The keeper assembly 6 is replaced by a latch bolt assembly having a horizontally oriented latch bolt that is biased towards its retracted position and is attracted by the magnetic element fixed to the lower end 34a. Such embodiments are disclosed in AU 2009/251007 A1, AU 2013/206766 A1, 2014/203446 A1, AU 2016/201778 A1, and AU 2018/256525 A1. Furthermore, it is also possible to reverse the roles of the magnet and the latch bolt in such an embodiment, i.e. have the horizontal latch bolt form the permanent magnet and have a ferromagnetic material fixed to the lower end 34a of the lower link rod 34. Moreover, the position of the latch bolt assembly 5 and the keeper assembly 6 may also be reversed, i.e. the latch bolt assembly 5 may be mounted on the closure member 2 and the keeper assembly 6 on the support 4.
[0170] A second embodiment of a magnetic latch assembly 1′ will be described with reference to FIGS. 11A to 18. Elements in the magnetic latch assembly 1′ will be indicated with the same reference numbers as corresponding elements in the magnetic latch assembly 1. The magnetic latch assembly 1′ is mounted on a closure system. The closure system comprises a closure member 2 that is hinged on a first support 3 and that may be fastened to a second support 4 by means of the magnetic latch assembly 1. In the illustrated embodiment, the closure member 2 is formed by a gate and the supports 3, 4 are formed by fixed 1′, but it will be readily appreciated that the magnetic latch assembly 1′ is also suitable for other kinds of closure members (e.g. a sliding closure member, a door, etc.) and/or supports. For example, the support may be formed by a closure member in case the magnetic latch assembly 1′ is used on a double gate.
[0171] The magnetic latch assembly 1′ generally comprises a latch bolt assembly 5 and a magnetic keeper assembly 6 as shown in FIGS. 11A and 11B. In the illustrated embodiment, the latch bolt assembly 5 is mounted on the closure member 2 and the magnetic keeper assembly 6 is mounted on the support 4, but it will be readily appreciated that these may be reversed. The latch bolt assembly 5 comprises a vertically oriented elongated housing 7 with a pull knob 8 protruding from the top thereof. The major difference between the magnetic latch assemblies 1, 1′ are the components in the bottom part of the housing 7 and underneath the housing 7. More specifically, the magnetic latch assemblies 1, 1′ are identical for all upper components in the housing 7, i.e. ell components from the knob 8 downwards to and including the lower link rod 34 are identical and will not be described again. However, while the magnetic latch assembly 1 had a vertically oriented latch bolt 14 protruding from the bottom of the housing 7 and an L-shaped bracket 10 underneath the elongated housing 7, the magnetic latch assembly 1′ is provided with a second housing 70 underneath the elongated housing 7 in which a horizontally oriented latch bolt 14 is placed. The latch bolt 14 is moveable along a horizontal translational motion between a retracted position (shown in FIG. 14A) and a latching position (shown in FIG. 14B) in which the latch bolt 14 protrudes from the side wall 72 of the housing 70. It will be readily appreciated that the elongated housing 7 and the bottom housing 70 together may be regarded as a frame on which the various components of the latch bolt assembly are mounted.
[0172] Due to the horizontal placement of the latch bolt 14, the magnetic latch assembly 1′ has different configurations for a right-handed closure member 2 (shown in FIGS. 11A and 12A) and for a left-handed closure member 2 (shown in FIGS. 11B and 12B). More specifically, the elongated housing 70 is always fixed in the same position with respect to the closure member 2, while the lower housing 70 together with its internal components is rotatable over 180° about the vertical direction 15 with respect to the elongated housing 7 as described in more detail below by reference to FIGS. 16 to 18. In this way, the side wall 72 from which the latch bolt 14 protrudes in its latched state is differently positioned with respect to the elongated housing 7 depending on the handedness of the closure member 2. The lower housing 70 positioning is done prior to mounting the latch bolt assembly 5 on the closure member 2.
[0173] The latch bolt assembly 5 is mounted on the closure member 2 as best illustrated in FIGS. 12A and 12B. In particular, the latch bolt assembly 5 is mounted on the closure member 2 by means of an upper L-shaped mounting bracket 73 and a lower L-shaped mounting bracket 74. The L-shaped mounting brackets 73, 74 have a first leg 73a, 74a that is fixed by a bolt 75 to the side of the closure member 2 and a second leg 73b, 74b on which two guide rails 76 are provided. The frame 7, 70 has corresponding guides that fit in the guide rails 76 to allow mounting the latch bolt assembly 5 by sliding it along the vertical direction 15. More specifically, the elongated housing 7 is provided with corresponding guides 112 (shown in FIGS. 17A and 17B) in its rear wall, while the housing 70 has corresponding guides 77 on both its front and rear side (i.e. the front and rear side are symmetrical), which sides change positions depending on the handedness of the closure member 2.
[0174] In order to fix the vertical position of the latch bolt assembly 5 with respect to the closure member 2, the second leg 74b of the lower L-shaped bracket 74 is provided with two projections 78 that fit into one of a set of parallel grooves 79 provided on the housing 70. This is shown in detail in FIGS. 13A and 19. The projections 78 are mounted on arms 80 that form part of a fixation element 118 that is fixed to the second leg 74b of the L-shaped bracket 74. More specifically, the fixation element 118 fits in the guides 76 on the second leg 74b of the L-shaped bracket 74 so that the fixation element 118 is fixed in the horizontal plane (i.e. the width direction 46 and the depth direction 38) with respect to the L-shaped bracket 74. A vertical displacement of the fixation element 118 with respect to the L-shaped bracket 74 is avoided by the square nut elements 100 which are inserted through corresponding openings 119 in the second leg 74b into corresponding grooves (best shown in FIG. 13A) in the fixation element 118. A through-hole 82 that extends in the vertical direction 15 is present between the fixation element 118 and the second leg 74b of the L-shaped bracket 74 the L-shaped bracket 74. Two set screws 81 are provided in the through-hole 82 which extend through a corresponding square nut element 100, each set screw 81 being individually adjustable (e.g. by using a hex key or the like). The L-shaped bracket 74 is usually made from metal (e.g. aluminium), while the fixation element 118 is usually injection moulded from a polymeric material (e.g. polyamide, in particular fibre-reinforced polyamide, or the like). The square nut elements 118 also ensure that any vertical forces exerted on the fixation element 118 (i.e. on the projections 78) are directly transmitted to the metal L-shaped bracket 74.
[0175] By rotating the set screws 81 closer together, the protrusions 78 are urged away from the second leg 74b of the lower L-shaped bracket 74 and towards the parallel grooves 79 provided on the housing 70. More specifically, one of (the upper one in FIG. 13A) the opposing end faces 126a of the set screws 81 acts as an engagement surface which engages the protrusions 78 and pushes them away from the L-shaped bracket 74. In this way, each protrusion 78 interlocks with a groove from the parallel grooves 79 thus preventing a further vertical motion of the housing 70 with respect to the lower L-shaped bracket 74. In other words, the vertical position of the latch bolt assembly 5 with respect to the closure member 2 is fixed. Since a plurality of parallel grooves 79 are provided on the housing 70, the vertical position of the latch bolt assembly 5 with respect to the closure member 2 may be adjusted by loosening (one or both of) the set screws 81 and moving the frame 7, 70 before again fastening the set screws 81. Due to the different possible rotational positions of the lower housing 70 with respect to the elongated housing 7, grooves 79 are provided on both sides of the lower housing 70 as shown in FIG. 20.
[0176] The use of two set screws 81 and two projections 78 is beneficial as it allows to operate the adjustment mechanism from either the upper side or the lower side of the lower L-shaped bracket 74. This is particularly advantageous since the lower L-shaped bracket 74 is mounted in two different vertical orientations depending on the handedness of the closure member 2 since the first leg 74a of the lower L-shaped bracket 74 is to be positioned between the closure member 2 and the support 4. Moreover, once the latch bolt assembly 5 is placed on the L-shaped brackets 73, 74, it is very difficult to reach and rotate the upper set screw 81. As such, depending on the handedness of the closure member 2, only one of the set screws 81 (i.e. the lower one) is rotated to cause the protrusions 78 to engage the grooves 79. Furthermore, the use of two projections 78 provides a stronger connection when compared to a single projection 78. Two arms 80 is also beneficial as this results in a latch bolt assembly 5 that is always hanging from one arm (i.e. the upper one) and pushing on the other arm (i.e. the lower one), while, in case of only a single arm, the latch bolt assembly 5 is either hanging or pushing depending on the orientation. Depending on the tensile strength and/or the compressive strength of the fixation element 118 which is mainly determined by its material (e.g. plastic) properties, the arms 80 may be prone to elongation or compression which could result in a shift in height.
[0177] Furthermore, by using two set screws 81, a stop is provided to limit movement of the set screws 81. More specifically, of the two set screws 81, one is stationary and the other one is being rotated to fix the height (which one depends on the vertical orientation of the L-shaped bracket 74). As such, the stationary set screw will act as a stop for the rotatable set screw as the opposing end faces 126a engage one another. Another advantage of this is that, as the end faces 126a engage one another, a further rotation of one of the set screws 81 urges the nut elements 100 away from one another causing them to be very robustly locked into the openings 119.
[0178] In a non-illustrated embodiment, the fixation element 118 is integrally formed with the L-shaped bracket 74. However, such an element is not easily injection moulded. Moreover, as described above, it is beneficial to form the L-shaped bracket from metal to provide the required strength.
[0179] FIG. 13B illustrates a variation of the height adjustment mechanism shown in FIG. 13A. More specifically, the two set screws are replaced by means of a single elongated partially threaded rod 81 which is rotatable from either end 81a, 81b (e.g. by means of a hex key or the like). The upper end 81b of the threaded rod 81 is accessible via opening 82. The fixation element 118 further comprises a stop 127 near its top which prevents the threaded rod 81 from being rotated too far (the stop could also be formed by an additional bolt, pin or the like to fix the threaded rod in its position after rotation). The threaded rod 81 is connected to the L-shaped bracket 74 by means of a single rectangular nut 100. Another difference is that the two arms are replaced by a single continuous arm 80 which is fixed to the fixation element 118 at both ends and has a single central protrusion 79. The continuous arm 80 is flexible and can be bent away from the L-shaped bracket 74. The threaded rod comprises a central area 126 with a decreased diameter which corresponds to the location of the protrusion 79. B rotating the threaded rod 81, the decreased diameter part 126 moves upwards so that the lower wall 126a engages the protrusion urging the protrusion towards the grooves 79. By mounting the protrusion 79 on a continuous arm 80 still avoids a shift in height that could occur in case the protrusion 79 is only connected to the fixation element 117 by means of single arm as this arm may be prone to elongation or compression depending on its tensile/compression strength.
[0180] As shown in FIGS. 12A and 12B, the housing 70 is also provided with a stop 83 that is mounted on the front side of the housing 70. In particular, the stop 83 includes guides 85 corresponding to the guides 77 on the housing 70, which guides 77 are used to engage the lower L-shaped bracket 74. The stop 83 is slid upwards and is fixed by means of bolts 84 that extend through openings 86 in the stop 83 and fit in holes 87 in the housing 70.
[0181] The internal structure of the lower housing 70 and the additional components of the latch bolt operating mechanism will be described with respect to FIG. 14A to 15. As described above, all components of the magnetic latch assembly 1′ from the knob 8 to the lower link rod 34 are identical to those in the magnetic latch assembly 1. However, where the latch bolt 14 is positioned directly on the slideable coupler 15 which engages the lower link rod 34 in the magnetic latch assembly 1, an additional puller 88 is present in the magnetic latch assembly 1′. The puller 88 is connected at its upper end to the lower link rod 34 in a rotatable fashion as described in more detail below with reference to FIGS. 16 to 18. It will be readily appreciated that, in a non-illustrated embodiment, a coupler 15 may be interposed between the lower link rod 34 and the puller 88. The puller 88 and is moveable by a vertical translational motion between a rest position (shown in FIGS. 14A and 14C) and an actuated position (shown in FIG. 14B). These positions are directly related to the position of the knob 8, i.e. when the knob 8 is in its rest position, the puller 88 is in its rest position and vice versa. The puller 88 has a bevelled surface 89, the function of which is described below.
[0182] The latch bolt 14 is positioned horizontally and is moveable between a retracted position (shown in FIGS. 14B and 14C) and a latching position (shown in FIG. 14A). A latch bolt spring 17 is positioned between the housing 70 and the latch bolt 14 in order to urge the latch bolt 14 towards its retracted position. In the illustrated embodiment, the inner end 14a of the latch bolt 14 is provided with a protrusion 90 which engages one end of the latch bolt spring 17. On the protrusion 90, there is provided a guiding pin 104 around which the latch bolt spring 17 is positioned. This guiding pin 104 prevents the latch bolt spring 17 from buckling. The latch bolt spring 17 is thus a compression spring in the illustrated embodiment. The keeper assembly 6 is provided with a magnet 19 which magnetically attracts the latch bolt 14 to move the latch bolt 14 against the latch bolt spring 17 towards its latching position. The latch bolt 14 is mounted to (more specifically suspended from) the housing 70 by means of two levers, namely an operation lever 91 and a support lever 92.
[0183] The operation lever 91 is pivotally connected to the housing 70 in a central area 91a by a transversely positioned pin 93 and is pivotally connected at its lower end 91b to the latch bolt 14 by another transversely positioned pin 94. The support lever 92 is fastened in a similar way at its upper end 92a to the frame by pin 95 and at its lower end 92b to the latch bolt 14 by pin 96. No other guiding and/or support means are required for the latch bolt 14, such that the latch bolt 14 is able to move with nearly no friction. The upper end 91c of the operation lever 91 is provided with a transverse pin 97 which engages the puller 88, in particular the bevelled surface 89 thereof. The levers 91, 92 are rotatable about their respective pivot pins 93, 95 between a first position (in which the latch bolt 14 is in its retracted position) and a second position (in which the latch bolt 14 is in its latching position). It will be readily appreciated that the levers 91, 92 may also be used as a latch bolt biasing means instead of and/or additional to the latch bolt spring 17. More specifically, the levers 91, 92 may be designed in order to automatically return to their rest position in which the latch bolt 14 is in its retracted state. As shown in FIGS. 14A to 14C, the latch bolt 14 does not engage the housing 70 in the vertical direction, thus reducing friction.
[0184] In order to further reduce possible friction, plastic rings 105, 106 are disposed between the levers 91, 92 and the latch bolt 14. More specifically, a plastic ring 105 is disposed between the transverse pin 94 and the latch bolt core 101 and a plastic ring 106 is disposed between the transverse pin 96 and the latch bolt core 101. Alternatively, the latch bolt core 101 (indicated in FIG. 15) could be made from a plastic material.
[0185] As best shown in FIG. 15, the latch bolt 14 has a ferromagnetic element 98 that may be attracted by the magnet 19. The ferromagnetic element 98 is preferably located as near to the magnet 19 as possible and is therefore located at the front 14b of the latch bolt 14. However, as the latch bolt assembly 5 is meant for outdoor use, a protective surface coating (not shown) is applied to the ferromagnetic element 98 in order to avoid oxidization of the ferromagnetic element 98. However, such coatings are easily damaged due to friction. As such, the ferromagnetic element 98 is flanked by two protective plates 99 that are made from stainless steel or other suitable materials. This avoids sideways damage to the ferromagnetic element 98 in case a sideways force is exerted on the closure member 2 when the latch bolt 14 is in its latched position.
[0186] FIG. 15 further illustrates that the latch bolt 14, at least the protective plates 99, slide along the housing 70. In other words, the housing 70 has a central hole (not indicated) in which the latch bolt 14 is suspended. This is beneficial in case the latch bolt 14 is in its latching position within the keeper assembly 6 and a user attempts to force open the closure member 2. More specifically, trying to open the closure member 2 causes the latch bolt 14 to be pushed against the keeper assembly 6 in the width direction (i.e. downwards in FIG. 15). This sideways force on the latch bolt 14 is then directly transferred (via the protective plates 99) to the housing 70 thus avoiding that the force would be exerted on the levers 91, 92. For a similar reason, namely to avoid excess forces on the levers 91, 92, the latch bolt 14 has a rectangular (in particular square) cross section and is disposed in a square opening in the housing 70. In this way, a rotation of the latch bolt 14 around its longitudinal axis is prevented or at least the forces associated therewith are transferred directly to the housing 70 and are not exerted on the levers 91, 92.
[0187] In the illustrated embodiment, no coupler 15 is present in the magnetic latch assembly 1′. However, the same functionality (i.e. allowing the knob 8 to be in its rest position with the latch bolt 14 in its retracted position) is included. More specifically, as best shown in FIGS. 14B and 14C, when the latch bolt 14 is in its retracted state, the puller 88 does not engage the operation lever 91 or the support lever 92 irrespective of the position of the puller 88. In other words, the puller 88 is free to move from its actuated state (shown in FIG. 14B) to its rest state (shown in FIG. 14C) without engaging the levers 91, 92.
[0188] The latch bolt assembly 5 operates in the following way. FIG. 14A shows the latch bolt 14 in its latching position due to the magnetic attraction from the magnet 19 in the magnetic keep assembly 6. When a user desires to open the closure member 2, the user pulls the knob 8 upwards from its rest position to its actuated position thereby pulling (through the upper and lower link rods 33, 34) the puller 88 upwards from its rest position to its actuated position. By the upwards motion of the puller 88, the bevelled surface 89 engages the pin 97 thereby pushing the upper end 91c of the operation lever 91 in the width direction 46 in a first sense and likewise pushing the lower end 91b of the operation lever 91 in the width direction 46 in a second sense which is opposite to the first sense. In other words, the operation lever 91 acts as a seesaw about its central fixed pivot 93 and the puller 88 with the bevelled surface 89 acts as a sliding cam with the upper end 91c of the operation lever 91 being the cam follower. This pulls the latch bolt 14 into its retracted position (i.e. the latch bolt 14 undergoes a horizontal translational motion) as shown in FIG. 14B. Once the latch bolt 14 is in its retracted position, the closure member 2 is unfastened and the user may open the closure member 2 and the knob 8 may be let go. Gravity will cause the knob 8 and the puller 88 to fall downwards to their rest position as shown in FIG. 14C. However, the latch bolt 14 remains in its retracted position due to the latch bolt spring 17 and the pin 97 does not engage the bevelled surface 89. It will be readily appreciated that the inclination of the bevelled surface determines the force required to operate the puller 88. More specifically, the larger the inclination (with respect to the vertical direction 15), the more force a user will have to exert when pulling the actuator 8 upwards. However, the travel path is shorter. A smaller inclination has the opposite effect, i.e. a longer travel path with a decreased force to be exerted.
[0189] In the illustrated embodiment, the operation lever 91 acts as a first-order lever with the pin 93 forming the fixed pivot, the puller 88 being the effort and the latch bolt 14 being the load. However, in other embodiments, the operation lever 91 may pivot about its upper end (like the support lever 83) with the puller 88 engaging a central part of the operation lever. In other words, the operation lever 91 may also be a third-order lever. Alternatively, the operation lever 91 may also be a second-order lever. However, a first-order lever is preferred since this allows a flexible adaptation between force-reduction or force-magnification depending on the magnetic attraction and the desired actuation force. As such, there is no need to include the second-order lever 35 between the upper and lower link rods 33, 34 which may then be formed into a single link rod. Moreover, while the horizontal displacement of the latch bolt 14 is directly proportional to the length of the lever for a second-order of third-order lever, the first-order lever also allows varying the displacement by the angle made between the first leg 91d and the second leg 91e of the operation lever 91 additional to variations possible by the lengths of the legs 91d, 91e.
[0190] In the illustrated embodiment, the operation lever 91 and the support lever 92 also limit the horizontal motion of the latch bolt 14. More specifically, in the latching position of the latch bolt 14 (see FIG. 14A), the lower arm 91e of the operation lever 91 abuts against the housing 70, while, in the retracted position of the latch bolt 14 (see FIGS. 14B and 14C), the support lever 92 abuts against the housing 70.
[0191] In the illustrated embodiment, the distance between the pivot points 93, 95 of the levers 91, 92 is substantially the same as the distance between the latch bolt engagement locations 94, 96. In other words, the levers 91, 92 are connected to the latch bolt 14 at different locations along the length of the latch bolt 14. The distance between these locations is preferably as large as possible to increase stability. In order to limit the size of the housing 70 (i.e. its width), the levers 91, 92 (at least the area between the pivot points 93, 95 and the engagement points 94, 96) are bent away from one another.
[0192] FIGS. 16 to 18 illustrate more details on the coupling between the puller 88 and the lower link rod 34 and on the coupling between the housings 7, 70. As described above, the elongated housing 70 is always fixed in the same position with respect to the closure member 2, while the lower housing 70 together with its internal components is rotatable over 180° about the vertical direction 15 with respect to the elongated housing 7. Once the housing 70 is in the correct orientation, one or more (two in the illustrated embodiment) screws 107 are screwed through the housing 7 and the housing 70 (in particular the shaft 108) as best shown in FIG. 20 thereby preventing rotation of the lower housing 70. Afterwards, the latch assembly 5 is mounted to the closure system, in particular by sliding it downwards from above the L-shaped brackets 73, 74 with the guides 76 of the brackets 73, 74 engaging the guides 77, 112 on the housings 70, 7, which guides 77, 112 are thus preferably continuous with one another.
[0193] The 180° rotation is possible without having to disconnect the housing 70 from the frame 7. More specifically, the top side 108 of the lower housing 70 forms a substantially cylindrical shaft 111 about which the elongated housing 7 is positioned. A fixation bolt 109 is fixed to the top of the shaft 108. The elongated housing 7 comprises an inner collar 110 against which the shaft 108 abuts on one side and the head of the fixation bolt 109 on the other. More specifically, the inner collar 110 has a top side 113 and a bottom side 114 (both indicated in FIG. 14C). The shaft 108 (which is part of the housing 70) abuts against the bottom side 114 of the inner collar 110 as shown in FIG. 14C, while the fixation bolt 109 abuts against the top side 113 of the inner collar 110 as shown in FIGS. 17A and 17B. In this way, the fixation bolt 109 ensures that the housing 70 is fixed with respect to the elongated housing 7 in the vertical direction 15 thus avoiding that these elements 7, 70 are detached from one another.
[0194] As best shown in FIGS. 17A and 17B, the top of the shaft 111 is also provide with a vertical protrusion 115 adjacent the fixation bolt 109. The inner collar 110 extends over about 270° of the elongated housing 7 thus limiting the motion of the fixation bolt 109 and the vertical protrusion 115, i.e. of the lower housing 70. More specifically, in a first orientation shown in FIG. 17A, the fixation bolt 109 engages a first abutment 110a which forms one end of the inner collar 110, while, in second orientation shown in FIG. 17B, the vertical protrusion 115 engages a second abutment 110b which forms another end of the inner collar 110. Alternatively, the vertical protrusion 115 is not present and the fixation bolt 109 abuts against both ends of the inner collar 110 depending on the orientation of the housing 70. As the puller 88 rotates together with the housing 70, the puller 88 is also rotatable about the lower link rod 34 since the lower link rod 34 is fixed to the elongated housing 7. This is best shown in FIG. 18 where the top part 88a of the puller 88 is rotatable about the bottom part 34b of the lower link rod 34. An assembly opening 116 is provided in the top part 88a of the puller 88 to allow assembly of the lower link rod 34 and the puller 88.
[0195] The magnet 19 in the magnet latch assembly 1′ is identical to that in the magnet latch assembly 1 and similar forces are exerted on the latch bolt 14 with similar forces being required in order to lift the knob 8.
[0196] It will be readily appreciated that various modifications are possible in which the advantages of the second-order lever between the link rods 33, 34 and/or of the locking mechanism and/or the low-friction latch bolt 14 and/or the height adjustment mechanism and/or the left-right reversibility are also obtained. For example, in an embodiment, the magnetic roles of the latch bolt 14 and the magnet 19 are reversed. In other words, the latch bolt 14 is a permanent magnet and element 19 is made from a ferromagnetic material (e.g. iron). The operation of the magnetic latch assembly 1 remains unaffected because the latch bolt 14 will still be attracted to the element 19 as this is fixedly positioned within the keeper assembly 6. Moreover, it is also possible that the latch bolt 14 and the magnet 19 are permanent magnets and/or electromagnets. Moreover, the position of the latch bolt assembly 5 and the keeper assembly 6 may also be reversed, i.e. the latch bolt assembly 5 may be mounted on the closure member 2 and the keeper assembly 6 on the support 4.
[0197] In both magnetic latches 1, 1′, the latch bolt 14 and the magnet 19 are oriented in such a way that the attraction force is in the same orientation as the unlocking movement. More specifically, in the magnetic latch 1, the latch bolt 14 is vertically attracted to the magnet 19 and is unfastened by moving the latch bolt 14 upwards in the vertical direction. While, in the magnetic latch 1′, the latch bolt 14 is horizontally attracted to the magnet 19 and is unfastened by moving the latch bolt 14 away in the horizontal direction.
[0198] It will be readily appreciated that the low-friction latch bolt 14 (i.e. the latch bolt 14 mounted to the housing 70 by means of two levers 91, 92) may also be used in less complex magnetic latch assemblies. An example of such a magnetic latch bolt assembly embodiment is illustrated in FIGS. 21A to 21C. The magnetic latch bolt assembly comprises a housing 70 in which a latch bolt 14 is suspended by means of two levers 91, 92. More specifically, the levers 91, 92 are pivotally connected to the frame by transverse pins 93, 95 and to the latch bolt 14 by transverse pins 94, 96. A latch bolt spring 17 (i.e. a compression spring) is disposed between the housing 70 and a protrusion 90 of the latch bolt 14. A guiding pin 104 is provided for preventing buckling of the latch bolt spring 17. The latch bolt spring 17 urges the latch bolt 14 towards its unlatching position (shown in FIG. 21C). The latch bolt assembly further comprises a follower 121 designed to cooperate with a spindle (not shown) which is connected to a door handle 8 or the like, i.e. an actuator. The follower 121 includes a rotary driving bit 123 which engages the latch bolt 14, in particular a protrusion 125 thereon. A biasing member (not shown), in particular a torsion spring, biases the follower 121 towards its rest position shown in FIG. 21C where the rotary driving bit 123 engages a stop 124 provided on the frame 70, although other means are known to limit movement of the follower 121.
[0199] In the rest position of the magnetic latch bolt assembly (shown in FIG. 21C), the latch bolt 14 is retracted due to the latch bolt spring 17. The door handle 8 (i.e. the actuator) cannot engage the latch bolt 14. When the closure member on which the magnetic latch bolt assembly is mounted is closed, the latch bolt 14 is attracted by magnet 19 towards its projecting position (shown in FIG. 21A). The roles of the magnetic elements 14, 19 may naturally be reversed. Once the magnetic latch bolt assembly is latched, actuating the door handle 8 (i.e. the actuator) causes the follower 121 to rotate in turn moving (i.e. swinging) the latch bolt 14 against the magnetic attraction towards its retracted position shown in FIG. 21B. It will be readily appreciated that other kinds of actuators may be used instead of the door handle. For example, the actuator may also be in the form of a push-bar or panic-bar.
[0200] A main advantage of this kind of magnetic latch assembly is that there is no need to have a latch bolt with an inclined front surface which, when closing a closure member into which or on which the latch bolt assembly is mounted, cooperates with a striker (not shown) to move the latch bolt 14 to the retracted position. In order for such inclined surfaces to properly operate, the closure member has to close with a sufficiently large force. In the present embodiment, this is no longer required as the rest position of the latch bolt is the retracted position thus always allowing the closure member to be closed even with a minimal closing speed.
[0201] This latch bolt assembly also illustrates that the levers 91, 92 are not necessarily part of the latch bolt operating mechanism. In other words, the levers 91, 92 may be used solely for suspending the latch bolt, while the operating mechanism is distinct therefrom. As such, the operation lever 91 in the magnetic latch 1′, in a non-illustrated embodiment, does not necessarily form part of the latch bolt operating mechanism and a different construction is possible where the puller 88 directly or indirectly engages the latch bolt 14 without required in the operation lever 91.
[0202] Although aspects of the present disclosure have been described with respect to specific embodiments, it will be readily appreciated that these aspects may be implemented in other forms within the scope of the invention as defined by the claims.
