Abstract
The invention relates to a cleaning machine (1) comprising a housing (10) and at least one hingeable element (20), as well as to the hingeable element (20) itself. The hingeable element (20) is detachably attachable to said housing via a hinge structure comprising at least two pairs of magnetizable or magnetic member surfaces (H1, E1; H2, E2). At least one surface in each pair exhibits a magnetic force for engagement with the other surface in said pair. A first member surface (E1; E2) in each of said pairs is supported by said hingeable element (20) and a second member surface (H1; H2) in each of said pairs is supported by said housing (10). When said hingeable element (20) is attached to said housing (10), said magnetic force is extending in a direction substantially in parallel with a magnetic centre axis (A.sub.m) extending between each first member surface (E1; E2). This provides a sufficient attachment force in the hinge structure both to allow the hingeable element (20) to stay attached to the housing during use, as well as to allow the hingeable element (20) to become detached easily from the housing (10), thus to function as a break away.
Claims
1. A cleaning machine comprising a housing and at least one hingeable element, which element is detachably attachable to said housing via a hinge structure comprising at least two pairs of magnetizable or magnetic member surfaces, where at least one surface in each pair exhibits a magnetic force for engagement with the other surface in said pair, and where a first member surface in each of said pairs is supported by said hingeable element and a second member surface in each of said pairs is supported by said housing, and wherein, when said hingeable element is attached to said housing, said magnetic force is extending in a direction substantially in parallel with a magnetic centre axis (A.sub.m) extending between each of the magnetic centre axes of said first member surfaces.
2. A cleaning machine according to claim 1, where said at least one hingeable element is pivotable around a pivot axis (A.sub.p) between at least one open and a closed position relative to the housing, and wherein preferably said pivot axis (A.sub.p) substantially coincides with said magnetic centre axis (A.sub.m), preferably at least when not in said closed position.
3. A cleaning machine according to claim 2, where said at least one hingeable element further can be positioned in at least one given angle () in said at least one open position, such as in a multitude of angles (.sub.1, .sub.2, .sub.3, .sub.4 . . . ) in different non-closed positions, such as a freely selectable angle, said angle being any between 0 and 360, preferably between 0 and 270, more preferably between 0 and 180, where said angle () is measured between a plane of said at least one hingeable element relative to a plane extending over edges in the housing.
4. A cleaning machine according to claim 1, where said at least one hingeable element and/or the housing is provided with at least one detach protrusion thereon in such a way that when the hingeable element is pivoted around said pivot axis (A.sub.p) to a certain angle (.sub.break) the at least one detach protrusion is interacting through the movement relative to the housing and/or hingeable element as a lever point.
5. A cleaning machine according to claim 1, wherein a shape of at least one, preferably all of said member surfaces perpendicular to said magnetic centre axis (A.sub.m) are circular or oval.
6. A cleaning machine according to claim 1, wherein at least one of said magnetic or magnetizable member surfaces is provided with a recess or through-going hole arranged around a magnetic center of said member surface.
7. A cleaning machine according to claim 6, wherein at least one of said magnet or magnetizable members in a pair comprises a pivot protrusion suitable for engagement with such recess or through-going hole in the opposing member, optionally said pivot protrusion is made from an elastic material, such as a polymer composition, such as an elastomeric composition, preferably the size of the diameter of said pivot protrusion is at least around 0.9 times, such as 0.7 times the size of the diameter of the opposite recess.
8. A cleaning machine according to claim 1, wherein at least one of said magnetic or magnetizable member surfaces is provided with an outermost non-magnetic or non-magnetizable protection layer, e.g. made of a polymer composition.
9. A cleaning machine according to claim 1, wherein the hinge structure is a pinless hinge structure.
10. A cleaning machine according to claim 1, wherein said cleaning machine is any one from the selection of a vacuum cleaner, such as a dry or a wet/dry vacuum cleaner, a pressure washer, and a floor cleaning machine, such as a carpet steam cleaner, a sweeper, or a scrubber.
11. A cleaning machine according to claim 10, the at least one hingeable element being a hingeable cover and said housing comprising at least one aperture which is coverable by said hingeable cover.
12. A cleaning machine according to claim 11 being a vacuum cleaner, and the housing comprising at least one vacuum chamber forming said aperture in said housing.
13. A cleaning machine according to claim 12, wherein a housing axis (A.sub.h), which extends between the magnetic centres of each of the second member surfaces being supported by said housing, is not coinciding with said magnetic centre axis (A.sub.m) when the hingeable cover is in a closed position relative to said housing and the vacuum cleaner is being used, or is coinciding with said magnetic centre axis (A.sub.m), when the hingeable cover is not in the closed position relative to said housing.
14. A cleaning machine according to claim 12, wherein said hingeable cover is movable in a direction perpendicular to said pivot axis, preferably in a direction perpendicular to a plane extending over edges in the housing forming said aperture, for a maximum movement distance being at least 3%, such as at least 5%, such as at least 10%, such as at least 20% of the diameter of one of the magnetic or magnetizable member surfaces.
15. A cleaning machine according to claim 14, wherein, when said vacuum cleaner is operative for creating a vacuum state in said vacuum chamber, said hingeable cover is movable towards said housing providing an airtight fit with said housing, preferable in contact with a peripheral flange on an edge of the housing.
16. A cleaning machine according to claim 1, where said hingeable element is a detachable accessory of said cleaning machine, such as a plate, an additional cover, a filter holder, a suction head accessory.
17. A hingeable element being detachably attachable to a cleaning machine housing via a hinge structure comprising at least two magnetizable or magnetic member surface pairs, at least two first magnetizable or magnetic members of said surface pairs being supported by said hingeable element and being adapted for engagement by magnetic force with at least two second magnetizable or magnetic members of said surface pairs being supported said cleaning machine housing, and where said hingeable element is adapted to, when magnetically attached to said cleaning machine housing, allow said magnetic force to extend substantially in a direction in parallel with each surface of the first members being supported by said hingeable element.
18. A hingeable element according to claim 17, which is a hingeable cover suitable to cover a vacuum chamber in a vacuum cleaner.
Description
BRIEF DESCRIPTION OF DRAWING
[0041] The invention will be explained more fully below in connection with a preferred embodiment and with reference to the schematic drawing in which
[0042] FIG. 1A, 1B show perspective views of a cleaning machine according to an embodiment having the hingeable element in a closed position and in an open position, respectively;
[0043] FIG. 2A, 2B show perspective views of a cleaning machine according to an embodiment having the hingeable element in a totally detached position and in a closed position, respectively;
[0044] FIG. 3 shows a perspective view of an embodiment of a box shaped cleaning machine housing provided with a hingeable cover;
[0045] FIG. 4 shows a perspective view of an embodiment of a box shaped cleaning machine provided with a hingeable cover;
[0046] FIG. 5A, 5B show section views of the vacuum cleaner as shown in FIG. 2B along the pivot axis, when the vacuum cleaner is in an inoperable state and when in an operable state, respectively;
[0047] FIG. 6A, 6B, 6C show side views of two different magnetic or magnetizable members, as well as a member provided with a pivot protrusion;
[0048] FIG. 7A, 7B, 7C show end views of the three members as shown in FIGS. 6A, 6B, and 6C; and
[0049] FIG. 8, 8A, 8B shows respectively a perspective view of the embodiment shown in FIGS. 1A and 1B of a cleaning machine provided with detach protrusions on the housing, and two cut side views showing the opened element before detachment and under detachment thereof of the embodiment of the cleaning machine as shown in FIGS. 2A and 2B, respectively.
[0050] In the following the invention is being illustrated by examples of a cleaning machine 1 being a vacuum cleaner. However, it is clear to the skilled person that different types of cleaning machines may easily be adapted according to the claimed invention, such as a dry or a wet/dry vacuum cleaner, a pressure washer, and a floor cleaning machine, such as a carpet steam cleaner, a sweeper, or a scrubber. Further, the invention is also being illustrated by the hingeable element in the examples of a cover, but may also form other parts of the cleaning machine, such as a detachable accessory, such as a plate, e.g. forming a structural part of the cleaning machine, an additional cover, a filter holder, or a suction head accessory. These hingeable elements may be provided on or in an interior or exterior part of the cleaning machine 1, as well as provided at, within, or on a side, upper, or lower surface thereof.
[0051] FIGS. 1A and 1B show, in a very schematic way in order to better indicate the features of the present invention, and in perspective views, a cleaning machine 1 in one embodiment of the invention having a hingeable element or cover 20 in a closed and an open position, respectively. The cleaning machine 1 is a vacuum cleaner comprising a housing 10 having the cover 20 magnetically detachably attached via a hinge structure to the housing 10. The cover 20 is provided in order to enter into contact with an edge 12 of the housing 10 to cover an aperture 13 for accommodating a vacuum generator (not shown) of the vacuum cleaner 1. The hinge structure comprises at least two pairs of magnetizable or magnetic members 11, 21 and 11, 21 provided with exposed surfaces E1, H1 and E2, H2, respectively. Each member pair 11, 21 are provided with their exposed surfaces E1, H1 facing each other, i.e. as opposing surfaces, each surface substantially extending perpendicular to a pivot axis A.sub.p extending between the geometric centres of each surface E1, H1.
[0052] The vacuum cleaner housing 10 is provided with the cover 20 which is adapted in size and shape to be able to fit over an aperture 11 of an interior space comprising a vacuum chamber, which is suitable for holding a motor and vacuum generator (not shown), and is in fluid communication with an opening with a flange 103 suitable for attaching and accommodating a suction hose (not shown). The housing 10 in general further comprise wheels 104, as well as further not indicated conventional features known to the skilled person to be provided on a vacuum cleaner 1, but these will not be discussed further herein, as they do not form part of the claimed invention. The cover 20 is provided with a handle 22, which is optional.
[0053] Each surface of the two surface pairs H1, E1 and H2, E2 engage in pairs in cooperation two-by-two and enables a simple yet functional magnetic pivotal attachment between the cover 20 and the housing 10. The magnetic hinge structure 11, 21; 11, 21 allow the cover 20 to pivot around the pivot axis A.sub.p at an angle relative to the housing 10 between the closed position as shown in FIG. 1A and e.g. an open position as shown in FIG. 1B. In FIGS. 2A and 2B, the pivot axis A.sub.p coincides with a magnetic centre axis A.sub.m, which extends between the geometric centres of the exteriorly exposed magnetic or magnetizable member surfaces E1 and E2, also termed first surfaces, of the element members 11, 11. The geometric centre of each surface of the element members 11, 11 also coincides with the position in which the magnetic field lines of the magnet or magnets extend from the surface E1 or E2 substantially perpendicular to said surface.
[0054] Within or on the hingeable element or cover 20 the members 21 are provided as two separate, similar magnetizable or magnetic members with each their first surface E1 and E2, respectively, being exposed to the exterior of the cover 20. This is also the case for the magnetizable or magnetic members 11, 11 of the housing 10. The remaining surface area of the members (shown by dashed lines) is embedded inside the plastic material forming the cover 20 or the housing 10. Alternatively, the members can be attached to an outer surface of the cover 20 or housing 10 preferably having at least one surface exposed, i.e. not covered by any material. Advantageously, a protecting layer of preferably non-magnetizable material can be provided on the exposed surface if an increased wear of this surface is anticipated during use, e.g. if the two surfaces E1, H2 in a pair lie close to each other, e.g. contact each other.
[0055] The skilled person will realize that any suitable number of member pairs may be applied, such as two, three, four, five, ten, or other practically suitable number, as well as any suitable material, size, magnetic field strength, shape of the members may be utilized.
[0056] Each element member 21, 21 is positioned with its exposed surface E1, E2 on opposing, mutually facing sides of two rectangular element protrusions 25, which extend substantially in parallel to each other and laterally along the cover 20 on the side edge thereof which faces the housing 10, the element protrusions 25 forming part of the cover 20. Each element member 21, 21 surface E1 and E2 are provided substantially flush with the element material forming each inner side edge of the two protrusions 25 of the cover 20. The two element protrusions 25 fit around a single protruding edge part 15, which is provided in the housing 10 and is provided with two magnetic members 11, 11, one on each side thereof with exposed second surfaces H1 and H2 facing away from other. Thus, the exposed second surfaces H1, H2 of the housing members 11, 11 embedded in the housing 20 are positioned inwardly relative to the corresponding two first member 21, 21 surfaces E1, E2 along the magnetic centre axis A.sub.m. FIGS. 2A and 2B show an embodiment of the present invention wherein the second surfaces H1, H2 are positioned outwardly relative to the first members E1, E2 along the magnetic centre axis.
[0057] In the embodiment of the vacuum cleaner shown in FIGS. 1A and 1B all four magnetizable or magnetic members 11, 11, 21, 21 are magnetic members, and each comprise a cylindrical neodymium magnet with a through going central hole extending in a direction along the pivot axis. The magnetic poles of all four magnets 11, 21, 21, 11 are provided substantially along the magnetic axis A.sub.m with alternating poles S/N, S/N, S/N, S/N in order for the largest amount of magnetic force being exerted between each pair to improve the engagement force of the cover 20 to the housing 10. The magnetic force is in this application then said to be extending in a direction in parallel or coinciding with the magnetic axis A.sub.m, at least of the magnetic members 21, 21. The skilled person would also realize, that other positioning of the poles are possible, such as S/N, S/N, N/S, N/S or N/S, N/S, S/N, S/N or N/S, N/S, N/S, N/S. Further, pairs comprising a metal or other magnetizable material such as an iron plate in combination with a neodymium or other magnet are also anticipated, such as Fe, S/N and S/N, Fe, or as S/N, Fe and Fe, S/N.
[0058] Other types of magnetic materials for the magnetic members can be anticipated and can comprise ferromagnetic materials, such as ferrite or alnico, ceramic magnetic materials or rare earth materials, such as neodymium or samarium-cobalt materials. The rare earth materials exhibit an increased magnetic force (remanence) of around 1 to 1.3 Tesla as well as increased magnetic energy densities of around 80 to 440 kJ/m.sup.3 relative to the magnetic force of ferromagnetic materials, which exhibit around 0.2 to 0.4 Tesla and magnetic energy densities of around 10 to 40 kJ/m.sup.3. Alternatively or in addition, an electromagnet positioned inside the housing can be employed, which is turned on only during operation and/or when the cleaning machine is plugged into an electrical outlet.
[0059] The term magnetizable material includes materials, which can be made temporally or substantially permanently magnetic by contact to a magnet after the removal of the magnet and materials, which responds to a magnetic force, such as many metals, in particular ferrite, Fe/Ni compositions, and metal/polymer or metal/ceramic composites.
[0060] Further, the section or surface shape of the magnetic or magnetizable member can comprises any suitable form, such as a cylinder, oval or circular disc, annular, spherical, square, and can be provided in one piece or in a combination of a multitude of such parts, can be provided with a plane, shaped, or worked exposed surface, can be recessed, or through bored, and any combination thereof. Preferably, the first and second surfaces in a member pair are substantially of corresponding size and shape.
[0061] The actual physical size of the magnetic member depends upon application, in particular as to the weight, extent and size of the hingeable element, as well as the magnetic force being exerted by the members in each pair, expressed in Tesla or kJ/m.sup.3, as well as whether the pair or pairs are magnet-magnet or magnet-metal, where magnet-magnet combinations generally tend to be about 1.5 times stronger than magnet-magnetizable combinations. In FIGS. 1A and 1B, a suitable section or exposed surface size of commercially available neodymium magnets can be around 1 cm to 3 cm in diameter, and the magnetic energy density can be around 80 to 200 kJ/m.sup.3. Further, during manufacture, by selecting the cover material such as a light polymer material, as well as designing the cover appropriately, as well as selecting size and strength of the magnets, the cover can become more or less easily detachable from the housing, which enables the manufacturer to design according to size of hingeable element and intended use of the cleaning machine in question.
[0062] The housing 10, at least at the position where the housing 10 is provided with the hinge structure, is preferably not made from magnetizable material, at least around the embedded magnet, in particular around the exposed surface or surfaces thereof. The hingeable element 20, such as cover, flap, door, partition, etc. may be made from any suitable material, such as wood or polymer. Preferably, the element 20 is not made from magnetizable material, at least in and around the area of support of the magnetic pair surfaces. Preferably, a light weight material is used for the elementthis reduces the magnetic force needed to hold the element in place, which reduces the manufacturing costs due to member costs.
[0063] In FIG. 1B is shown the cleaning machine housing 10 with the cover 20 in an open position at an angle thereto. As discussed above, the type and force of members, cover design, as well as material etc. may be selected in order for the attachment force between the two member pairs to allow the cover 20 to be held such a continually open position at that angle . Either held in that angle specifically, orif the magnetic force is further increased or cover weight/design decreasedheld continually in any angle between 0 and a larger angle than , until the upper surface of the cover 20 makes contact with an edge of the protruding edge part 25 of the housing 10.
[0064] However, by increasing the hold between the cover 20 and the housing 10, the ease and detachability of the cover 20 from the housing 10 is decreased, and the break away function may be lowered. So it is preferred to select and control the parameters of member pair strength and cover/housing design in order to reach a workable relation between these two functions.
[0065] In FIG. 1B, in addition to the magnetic hinge structure, the cover 20 can further be aided in staying securely in the closed position by providing a first magnetizable or magnetic closure plate 14 on the housing 10 on the edge 12 of the aperture 13 in the housing 10. The closure plate can cooperate magnetically and enter into contact with a second magnetizable or magnetic closure plate 24.
[0066] In FIGS. 2A and 2B are shown one embodiment of the cleaning machine according to the invention having inwardly positioned element member surfaces E1, E2, relative to the housing member surfaces H1, H2, as opposed to the embodiment shown in FIGS. 1A and 1B.
[0067] In both embodiments, FIG. 1A-2B, the cover 20 is able to be completely detached and removed from the housing 10, as is shown in FIG. 2A. This may be done in several ways, the detachment force being dependent upon the number and pair attachment force the user is moving against, e.g. by a user gripping manually and firmly by the handle 23, when the cover 10 is provided in the closed position as shown in FIG. 2B, and moving the cover 20 e.g. up along an angle with the housing 10, maybe while the user slightly twists the cover 20 on the magnetic centre axis A.sub.m, and pulls vertically up and away, or by pulling on the cover 20 directly towards a user standing in front of the side of the opening 103 on the housing 10, or as mentioned above, by overriding the maximum angle, the cover 20 can travel towards the two protruding edge parts 25, in this case. A user may also pull in one corner of the cover 20 or pull in the handle 22 obliquely to detach the cover 20 from the housing 10.
[0068] FIG. 2A also show that the magnetic centre axis A.sub.m extends between the geometric centres of the magnetic members 21, 21 provided in the cover 20, and that the pivot axis A.sub.p to be achieved extends between the geometric centres of the housing elements 11, 11, as well as in parallel with the magnetic centre axis A.sub.m as herein shown. FIGS. 1A and 1B show that when the cover 20 is attached to the housing 10, the magnetic centre axis A.sub.m substantially coincides with the pivot axis A.sub.p, and is at least provided in parallel to each other.
[0069] The cover is also easily re-attachable, as shown by the arrow in FIG. 2A, the user holds the cover 20 manually in a position where the element protrusion 25 draws near the interspace between the two housing protrusions 15, 15 for the magnetic force between the magnetic members 11, 21 and 21, 11 to be increasing and guide the cover 20 into place there between and attach to the housing 10. FIG. 2B also show the visually pleasing appearance of the cleaning machine 1 presenting the cover 20 in a closed position on the housing 10.
[0070] FIGS. 3 and 4 show two embodiments of the present invention, and illustrate some of the different shapes and forms of the housing 10, such as being box-shaped as well as two different positionings of the members with the two pairs of surfaces E1, H1 and E2, H2.
[0071] FIG. 3 shows a floor cleaning machine housing 10 comprising a substantially square box-shaped housing 10, provided on its entire top face with a cover 20, as opposed to the embodiments shown in FIG. 1A-2B, where approximately only half of the top face of the housing 10 was provided with the cover 20. Further, two ferrite-iron cylinders are provided as element members 231, 231 in the cover 20 to engage magnetically with two cylindrical neodymium magnets 131, 131 and provide a pivotable, detachable cover 20 thereon. By providing the magnetic members 131, 131 inside the housing 10 and not the cover 20, the members 231, 231 in the cover 20 does not in error magnetically attract any other magnetic or magnetizable object along the way, if or when the cover 20 is being detached and reattached again.
[0072] FIG. 4 shows an embodiment of a cleaning machine 1 according to the invention, where the two surface pairs E1, H1 and H2, E2 are provided as the exposed inner end surface of a circular magnetic plate member 241 on an side edge of the square cover 20, the two exposed circular exteriorly facing end surfaces of an elongated cylindrical iron member 141, and the exposed inner surface of a further circular magnetic plate member 241 on the opposing side edge of the square cover 20. This provides a visually more attractive surface, when all hinge structure members and surfaces are hidden, or integrated into the design of the cleaning machine 1. Further, manufacture of the housing 10 and cover 20 is eased since the provision and positioning of the members therein can be provided without the use of special tools, and can be provided during molding of the housing 10 and/or cover 20.
[0073] The hingeable element as well as the magnetic hinge structure may be positioned internally (not shown) or externally relative to the housing, see FIG. 1-4, as well as on or at a side, top, or bottom surface thereof.
[0074] FIGS. 5A and 5B show a vertical longitudinal cut section along the pivot axis A.sub.p of FIG. 2B of the cover 20, hinge structure and an upper part of the housing 10, when the cover 20 is in the closed position relative to the housing 10. FIG. 5A shows the relative position of the cover 20 when the vacuum cleaner 1 is not running its vacuum generator, and FIG. 5B shows the relative position of the cover 20 when the vacuum generator is running and creates a vacuum suction chamber below the cover 20 within the vacuum cleaner housing 10, i.e. when the vacuum cleaner 1 is turned off and on, respectively.
[0075] FIG. 5A show the cover 20 being in a position in which the pivot axis A.sub.p is coincident with the magnetic axis A.sub.m as defined by the magnets 21. In this position, which is determined by the forces of the two member pairs each comprising magnets 21 and 11 holding the cover 20 in place relative to the housing 10, there is a gap d between each of member pairs comprising the magnets 11 and 21. This gap d may be purposefully provided and of a certain size, or it may be there due to the large design tolerances, which are possible with the present invention. Advantageously, the gap d is not larger that the span with which the magnetic forces between the two magnet surfaces facing each other are able to operate effectively. Also, advantageously, the gap d may also be reduced, even to zero, in which case the exposed surfaces of the magnets 11, 21 may risk friction damages over the operative life of the cover 20 and housing 10. An outermost non-magnetic or non-magnetizable protection layer may then be provided, e.g. made of a polymer composition. The protection layer may comprise paint, lacquer, binder, rubber, tape, wood, and/or other preferably non-metallic or non-magnetizable material, such as a gel, wax, or lubricant.
[0076] Moreover, a height h between the hinge part of the cover 20 and a flange 12 is provided along the inner wall 10a of the housing 10 i.e. on a side surface of the aperture 13 in the housing 10 and provides a resting place or a maximum distance with which the cover 20 may pass into the housing 10. As may be seen from FIG. 5A, when the vacuum generator is not running, the hinge part of the cover 20 soars between the member pairs comprising the magnets 11 located in the housing 10 and the magnets 21 located in the cover 20. This effect is due to the mutual forces exerted by the magnets 11 and 21. Thus, when the hinge part of the cover 20 is in this position, and the vacuum generator is off, the cover 20 may be very easily be opened and pivoted around the pivot axis A.sub.p. The hinge structure enables the cover 20 to be kept in position by the mutual forces of the magnets 11, 21 of the member pairs and provides a hinge structure in which there is practically no resistance due to friction, and, thus, very low forces are required to move the cover around the pivot axis A.sub.p.
[0077] FIG. 5B shows a situation wherein the vacuum generator is running and works to generate a vacuum chamber thus created within the housing 10. As shown in FIG. 5B the vacuum chamber causes the cover 20 to move towards the flanges 12 thereby enables a tight closure of the generated vacuum chamber within the housing 10. This is due to the fact that the downwards acting suction force created by the vacuum chamber by the vacuum generator is larger than the magnetic forces provided by the magnets 11, 21 of the member pairs which were able to keep the hinge part of the cover 20 in the position as shown in FIG. 5A when the vacuum generator was not running.
[0078] Thus, when the vacuum generator is running, i.e. the vacuum cleaner is running, the cover 20 gets sucked towards the flanges 12 on the housing 10 to form a substantially air tight closure of the vacuum chamber in the housing 10, this increases the vacuum generating effect. In this situation, as depicted in FIG. 5B, the cover 20 is displaced in a downwards direction of the drawing so that the magnetic axis A.sub.m no longer coincides with the pivot axis A.sub.p. The fact that at least the part of the cover 20, wherein the hinge structure is provided, easily can be displaced provides a high amount of flexibility to the cleaning machine. This allows the cover 20 form an air tight closure with the peripheral flange 12 in the housing 10 when the vacuum generator is running and when not running the cover 20 may easily be opened and optionally entirely removed from the housing 10, which allows access to the interior of the housing 10.
[0079] As it may be seen in FIG. 5B the height h is eliminated when the vacuum generator is running, while the gap d between the magnets is essentially maintained. However, the designed height h should not exceed a maximum height which is the height where the magnetic force between the exposed surfaces is no longer effective to hold the cover 20 in place, which maximum height depends on the magnetic force exerted between the member pairs, the dimensions of the member surfaces, cover 20 and/or housing 10, the positioning and design of the pivotable element on and relative to the housing 10, the weight of the cover 20, the diameter D of the through hole in the member relative to the diameter of the exposed member surface, etc. In order to increase the effect of the air tight closure, the contacting upper surface of the peripheral flange 12 and/or the lower surface 20a of the cover 20 which contacts the flange 12 at a peripheral edge of the lower surface 20a may be provided with an elastic material, such as an elastomer. Advantageously, the cover 20 is movable in a direction perpendicular to the pivot axis A.sub.p, preferably in a direction perpendicular to a plane extending over edges in the housing forming said aperture, for a maximum movement distance being at least 3%, such as at least 5%, such as at least 10%, such as at least 20% of the diameter of one of the magnetic and/or magnetizable member surfaces.
[0080] The FIGS. 6A to 7C show different embodiments of members comprising magnets, which are suitable for use in the hinge structure of the invention. Alternatively, they can also show the design of different embodiments of magnetizable members, made from e.g. iron.
[0081] FIG. 6A shows a magnet 11 seen from the side, and FIG. 7A shows this magnet 11 seen from the front, exhibiting a member surface. As may be seen, this particular magnet 11 is a solid cylinder comprising a massive core of a magnetic material, which may be an advantage when requiring an increased magnetic force.
[0082] This is in contrast to the two members comprising magnets 11 shown in FIG. 6B, FIG. 6C, FIG. 7B and FIG. 7C, which all show a member 11 having a through-going hole 40, advantageously provided in the centre of the magnet, thus forming a cylinder. This hole 40 is provided for the magnet 11 to exert a directional magnetic force, which aids in positioning the two members of a pair essentially along the magnetic axis A.sub.m. In magnets, a central hole may also increase the effective magnetic field, if provided along it, and thereby increase the magnetic forces exerted between two magnets, 11, 22 or one magnet and one magnetizable member.
[0083] In FIGS. 6C and 7C, the through-going hole encompass a body, e.g. of elastomeric material, whichwhen the magnet is provided in the housing or pivotable elementprovide a pivot protrusion 45. Such a pivot protrusion 45 may engage with a corresponding hole in an opposite hinge structure member and make it easier to control the movement of the cover 20 during any pivot action. Further, the exposed projecting part of the pivot protrusion 45 is made of an elastic, preferably elastomeric material for an easier fit of the cover 20 inside the housing 10. Less magnetic force is then required between the member pairs.
[0084] One or both of the magnetic or magnetizable member surfaces in a pair may further be provided with a detach slit between said recess and one side of said member in order to enable sliding out said pivot protrusion, when the hingeable element 20 is being pivoted and detached from the housing 10. The detach slit may be provided in a magnetizable or magnetic member at either surface, as a recess therein or though-going.
[0085] FIG. 8 zooms in on part of the upper surface of the cover 20 and upper surface of the housing 10, wherein are provided two detach protrusions 30 in an upper part of the single protruding edge part 15 of the housing 10, as is similar to the embodiment shown in FIGS. 1A and 1B. These two detach protrusion 30 are provided in parallel to the pivot axis A.sub.p within the housing 10 and work in a similar manner as the detach protrusions 30A as shown in FIGS. 8A and 8B, but the latter are instead provided in the two protruding edge parts 15, as is similar to the embodiment shown in FIGS. 2A and 2B having inwardly positioned element member surfaces relative to the members in the housing 10.
[0086] FIG. 8A shows the cover 20 being pivoted open into such an angle wherein the detach protrusion 30B on the cover 20 is being placed between the two detach protrusions 30A on the housing 10. Thus, when the cover 20 is pivoted for a lower angle, the protrusion 30B remains within the valley between the two protrusions 30A and thus the magnetic axis A.sub.m (indicated by the leftmost cross) is moved further away from the pivot axis A.sub.p (indicated by the rightmost cross), whereby the magnetic force between the member surfaces is reduced and thus the removal of the cover 20 from the housing 10 is further eased. The detach protrusions 30, 30A, 30B may additionally function as a notch and latch for keeping the cover 20 in that angle and hold it there in one given open position.
