LATCHES FOR GATES AND DOORS

Abstract

A latch has a displaceable latching element in a housing for engagement with a separate striker arm to be latched behind an engagement shoulder of the latching element. The housing mounts a cylinder lock to receive a key from the front. A rotor is mounted on the rear of cylinder lock and rotation of the key rotation the rotor to drive a locking element to engage and lock the latching element. The rotor may also be axial displaceable against spring biasing responsive to a rear unit pushing element whereby unlocking from a rear cylinder lock may rotate the rotor to unlock and pushing causes the latching element to be displaced against its biasing to release the striker arm. Embodiments include a gravity biased and manually opened latch and a spring biased self-locking embodiment.

Claims

1. A latch for holding closed a gate (or door) wherein the latch is adapted to co-operate with a striker arm, the latch comprising: (a) a housing in which (b) a displaceable latching element is mounted to be displaceable from a latching position towards an open position in which the striker arm is released for gate opening, and (c) the latching element having a latching shoulder to retain the striker arm when engaged behind the latching shoulder and having an engagement surface adapted to be engaged by the striker arm when the gate is moved towards a closed position to displace the latching element and for permitting relative movement of the striker arm to adopt a position behind the latching shoulder, (d) a locking element for locking the latching element and adapted to be displaced upon actuation of the key-operated lock between a locking position, in which movement of the latching element is restrained from moving, and a displaced position in which the latching element is free to be moved, (e) the locking element being in the form of a rotor rotatably mounted in the housing, and the rotor is axially displaceable when in the displaced position, and (f) the rotor being mounted on a base portion of the housing and capable of being displaced axially by a rear actuating unit having a connection through an aperture in the base portion of the housing for unlatching the latching element.

2. A latch as defined in claim 1, wherein the lock is a cylinder lock.

3. A latch as defined in claim 2, wherein the rotor is rotatably mounted about the cylinder lock axis.

4. A latch as defined in claim 3, wherein the rotor has rotary motion of about 20 between the locking position and displaced position.

5. A latch as defined in claim 3, wherein a rear portion of the rotor remote from the cylinder lock is connectable to the remote actuating unit.

6. A latch as defined in claim 5, wherein the rotor is displaceable along the axial direction of the cylinder lock and is biased to a position away from the front cylinder lock, the rotor having a projecting element which is adapted to displace the latching element from the latching position towards an open position when the rotor has been moved from a locking position into a position in which the latching element is free to be moved, and the rotor is displaced against the biasing.

7. A latch as defined in claim 1, in combination with a rear actuator unit which has an axially displaceable element operable to displace the latching element remotely.

8. A latch as defined in claim 7, wherein the axially displaceable element is operable to engage with and displace the rotor against spring biasing to cause remote actuation of the latching element to open the latch.

9. A latch as defined in claim 7 or claim 8, wherein there is a rear lock in the rear actuator unit which is adapted to be connected to transmit rotation to the rotor from the locking position to the displaced position and from the displaced position to the locking position, whereby either the lock of the latch or the rear actuator unit lock can be used either to lock the latch or to permit it to be opened.

10. A latch as defined in claim 1, wherein the latching element is partially enshrouded in the housing with a protruding portion extending out of a face slot so as to facilitate manual lifting of the latching element when a lock has been unlocked.

11. A latch as defined in claim 1, wherein the latch is configured as a gravity latch and the latching element is pivotal and is biased by gravity to the latching position.

12. A latch as defined in claim 7, wherein the rear actuating unit is provided with a push button mounted to be depressed axially and to drive a mechanism to turn the rotor so that further action then causes the latching element to be displaced.

13. A latch as defined in claim 18, wherein the latch has a self-locking function, with the latching element enshrouded in the housing and displaceably by an internal mechanism to release the striker arm, the latching element being biased from its latching position towards an open position at which the striker arm is released so that the gate can be opened, return motion of the striker arm urging the latching element to move against its biasing to release the internal mechanism which operates through its own biasing to engage a retainer with the latching element to close the latch.

14. A latch as defined in claim 13, wherein the internal mechanism comprises the locking element having biasing to bias it towards the locked position and the latching element has an interference portion operable, when the latching element has been displaced away from the latching portion, to prevent the locking element returning to its locking position.

15. A latch as defined in claim 14, wherein the latching element is in the form of a laminar element substantially wholly enclosed in the housing for pivotal movement about a horizontal axis within the housing, a spring being provided for biasing the laminar element towards the open position.

16. A latch as defined in claim 14, wherein the latch is adapted for co-operation with an optional rear actuator unit to be mounted on the opposite side of a gate post to that of the latch, and the locking element is structured so that it can move relative to a base portion of the housing and the base portion of the housing is adapted to receive therethrough an actuating element associated with the rear actuator unit for operating the mechanism and moving the locking element from the locking position to a displaced position.

17. A latch as defined in claim 1, wherein the connection is in the form of a single actuating element provided for passage through a hole extending through the gate post for transmitting all displacement functions from the rear actuating unit to the rotor.

18. A latch for holding closed a gate (or door) wherein the latch is adapted to co-operate with a striker arm, the latch comprising: (a) a housing in which (b) a displaceable latching element is mounted to be displaceable from a latching position towards an open position in which the striker arm is released for gate opening, and (c) the latching element having a latching shoulder to retain the striker arm when engaged behind the latching shoulder and having an engagement surface adapted to be engaged by the striker arm when the gate is moved towards a closed position to displace the latching element and for permitting relative movement of the striker arm to adopt a position behind the latching shoulder, (d) a key-operated lock mounted in the housing and having a key operation for unlocking the latch, (e) a locking element for locking the latching element and adapted to be displaced upon actuation of a key-operated lock between a locking position, in which movement of the latching element is restrained from moving, and a displaced position in which the latching element is free to be moved, the locking element being in the form of a rotor rotatably mounted in the housing, and (g) the rotor having a portion remote from the lock capable of being engaged by a remote actuating unit which may be mounted on an opposite side of the gate post to the latch for remotely operating the latch via the rotor.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Embodiments of the invention will now be described with reference to the accompanying drawings of which:

[0048] FIG. 1 is an exploded view of a front unit for a latch embodying the invention;

[0049] FIG. 2 is an exploded view of a complementary latching arm intended to be fitting to a gate;

[0050] FIG. 3 is an exploded view of a cartridge assembly for the lock unit of FIG. 1;

[0051] FIG. 4 is an exploded view of a rear access unit for use with the embodiment of FIG. 1;

[0052] FIG. 5 is a cross-sectional view through the front unit showing the tongue in a latching position but prior to engagement with a striker bar;

[0053] FIG. 6 is a front elevation of the front unit of FIG. 5;

[0054] FIG. 7 is a view corresponding with FIG. 5 showing engagement by a striker bar about to engage and rotate the latching tongues to release the rotor to lock the tongue in a down position (as shown in FIG. 5);

[0055] FIG. 8 is a part sectional rear of the body view on an enlarged scale taken in a plane at right angles to the axis of the cylinder lock and rotor showing inter-engagement between the tongue and the rotor prior to engagement of the striker bar, the rotor being held displaced from its final locking position; and

[0056] FIG. 9 corresponds with FIG. 7 but shows the components when in the locked position.

[0057] FIG. 10 is an exploded view of a front unit for a latch of a second embodiment;

[0058] FIG. 11 is a side elevation of the second embodiment;

[0059] FIG. 12 is a front elevation of the second embodiment;

[0060] FIG. 13 is a central cross-sectional side elevation of the second embodiment with an optional rear locking unit in position and;

[0061] FIG. 14 is a plan view of the embodiment of FIG. 13 positional on a gate post with a striker arm unit positioned on a gate.

[0062] DETAILED DESCRIPTION OF THE DRAWINGS

[0063] Referring first to the exploded view of FIG. 1, the front unit for a latch assembly is illustrated and is in the form of self-locking assembly with automation opening when key actuation of a lock occurs. The front unit is adapted to cooperate in use with a striker arm assembly shown in FIG. 2 and optionally to be employed with a rear access unit shown in exploded view in FIG. 4. As shown in FIG. 1, the latch unit comprises a housing 20 assembled from a base unit 22 and a front shell 24 within which is mounted a locking cartridge assembly 26 for cooperation with a pivotal latching element in the form of a tongue 28. The tongue is mounted in the shell 24 on a pivot pin 30 and the tongue is adapted to be biased upwardly to its open position by a helical extension spring 32 which, at its upper end, is mounted on a mounting pin 34 and, at its lower end, is connected directly to the tongue.

[0064] The base 22 is generally L-shaped in plan view and has a side leg 36 adapted to be engaged over the face of a gate post and secured to the gate post by screws 38. A main leg 39 of the base is symmetrical with two vertically spaced apertures 40A and 40B and this leg is also adapted to be secured to the gate post by upper and lower screws 42. The shell 24, when the components are assembled inside, is fitted to the base by a series of four screws 44 from the rear of the base into the shell 24 with the cylinder lock 46 of the cartridge engaged in a corresponding aperture 48 in the shell and a rear barrel portion 50 of the cartridge engaged in the lower aperture 40A.

[0065] So that the gate latch can be fitted to either left hand or right hand opening gates, the unit can be reassembled with the base 22 rotated through 180 so that the opening 40B is lower and adapted to be engaged by the barrel 50.

[0066] The striker pin unit of FIG. 2 is adapted to be fixed to an edge portion of a gate and for that purpose has an L-shaped striker bracket 60 with a side leg 62 adapted to be secured to a side face of the gate by two fixing screws 64 and the other leg of the bracket has an integral upstanding body portion 66 also adapted to be secured to the gate but through a front face by two screws 68. The body portion mounts a steel striker pin 70.

[0067] FIG. 3 shows details of the cartridge 26 which comprises a plastic moulded holder 72 having a cylindrical portion 73 at one end to accommodate the cylinder lock 46 and a part cylindrical coaxial portion 74 for accommodating a locking element in the form of a rotor 76. A torsion spring 78 mounts over a rearwardly extending barrel 50, the barrel having a square-shaped axial aperture for accommodating a square actuation bar of a rear unit described below. Upon assembly, the torsion spring 78 is mounted to bias the rotor anti-clockwise as seen in FIG. 1 and FIG. 3 towards its locking position. The rotor has a front barrel 80 with a rectangular axial slot accommodating a conventional flat operating bar 79 extending from the cylinder lock 46. The cylinder lock conventionally has a degree of lost motion so that initial turning by a key does not turn the bar 79 or the rotor but further action in a clockwise sense (as seen in FIG. 1 and FIG. 3) then turns the rotor against its spring biasing to disengage a tongue retaining finger 82 of the rotor to release the tongue 28 to move upwardly under the biasing of spring 32, thereby releasing a striker arm so that the associated gate may be opened. The torsion spring 78 then acts to urge the rotor anti-clockwise (as seen in FIG. 1 and FIG. 3) until the side face of finger 82 inter-engages with a side face of the tongue 28 thereby holding the latch mechanism open and ready to be displaced by the striker pin when the gate is closed.

[0068] For this purpose, the tongue 28 has a protruding leg 84 (see FIG. 1) which interferes with the side of the finger 82 when the tongue is in the closed position. The profile of the tongue includes an abutment shoulder 86 configured such that when impacted by the striker arm 70, the tongue is rotated anticlockwise from the open position as seen in FIG. 1 to move the leg 84 rearwardly of the location of the finger 82, thereby releasing the rotor to turn under the force of the torsion spring 78 in an anticlockwise direction so that locking is automatically achieved.

[0069] More detail of assembly is shown in FIG. 5 in which, for ease of reading the drawings, the extension spring 32 is shown not engaged with the tongue so it has fallen under gravity the position it will have adopted when pushed in an anticlockwise direction by a striker bar. FIG. 5 is a section in a central plane and shows the space around the leg 84 of the tongue, the side face of the tongue acting as an interference element for a side face of the finger 82 of the rotor (which is visible in FIG. 5).

[0070] Referring now to FIG. 4, the optional rear access unit has a housing 90 of general L-shape and having a side leg 92 adapted to be fixed by screws 93 to the side of a gate and a casing 94 adapted to mount a lock 96 and an actuator assembly 98. The lock is mounted in a cap 100 which extends axially within a corresponding passage in the casing 94. The housing 90 also mounts a base element 102 to retain lock 96 in button 100. The actuating unit has a body portion 103 so that the lock and the button are biased to an outward position. The left hand end of the actuator comprises a barrel 105 having a rectangular slot into which the end of the operating bar 106 of the cylinder lock 96 engages for transmitting rotational force. The right hand end of the actuator 104 comprises a substantially square cross-section drive bar for engaging in the barrel 50 of the rotor 76. Thus, by virtue of the lock 96 being a left hand operating lock, a key is rotated anti-clockwise to take up initial lost motion and then further displaced to rotate the bar 104 clockwise when seen in the view of FIG. 4, whereby the rotor is rotated towards its opening position and can release the latching tongue to more upwardly under its spring bias.

[0071] In this embodiment the cap 100 is either not axially displaceable or, if axially displaceable, it is so by virtue of the bar 104 not fully penetrating the cavity in the rotor. In either event, any movement of the button if possible does not cause any function whatsoever but the structure described above has useful design criteria so that the unit may be useable in a second embodiment or, at least, many components of FIG. 4 are useable so that the manufacturer can cost effectively assemble and provide different embodiments for different market needs. For the purpose of this first embodiment with the self-locking front unit, there is no purpose in the cap 100 being axially displaceable.

[0072] In summary, the embodiment described above lends itself to efficient robust construction with relative simplicity in terms of the number of components and assembly. Furthermore, an important aspect is ease of fitting with hand tools and handheld drills to gates and gate posts. A single aperture is all that is needed to extend between the rear wall and front wall of a gate post in order to mount the optional rear access unit to engage in alignment with the front latch assembly. By contrast, if drillings are required at spaced parallel locations for two operating actuators, there is a great difficulty in achieving on site precision with hand tools.

[0073] Referring to the second embodiment with reference to FIGS. 10-14, like parts have been given like reference numerals, even though the specific configuration of certain parts may differ. In the case that a part is of a modified form compared with the first embodiment for different functionality, its reference numeral is 200 greater than the reference numeral used with reference to the first embodiment.

[0074] A significant difference in the second embodiment is that there is not automatic or self locking functionality but instead a lockable cylinder lock (46, 96) is provided in each of front and rear units and either may be actuated to unlock and leave unlocked the latch or manually to lock the latch. Either lock may be turned to unlock the latch and, in this embodiment, the tongue 228 has a projecting tab 229 having a finger engagement tip so the tongue may be lifted manually. In this instance the tongue is profiled so as to have a leading nose portion 231 which is adapted to be impacted by the striker pin when a gate is closed so as to rotate the tongue than upwardly to permit the striker pin to engage behind the latching shoulder and the tongue drops down under gravity in this embodiment to perform the latching function. Adaptations of such an embodiment include providing a lock in either or neither of the front or rear units but using interior components such as the rotor. Thus a suite of embodiments for different applications are based on the same interior rotor arrangements.

[0075] A key distinction of the rear operating unit in the illustrated embodiment is that the lock 96 is mounted in a depressible button 100 and the rotor 276 in the front unit has limited axial movement against the restoring force of a compression spring 223. The arrangement is such that opening the latch from the rear of the gate requires the button 100 to be pressed so that the actuating bar 104 moves forwardly and thereby pushes the rotor to a limited axial extent, providing it is in the unlocked position to engage a rear surface of the tongue to push it upwardly through a rotation about its pillet.

[0076] In the locked position the rotor, however, has its upwardly projecting finger engaging in front of the rear leg of the tongue thereby preventing it moving forward.