A mounting mechanism

Abstract: A mounting mechanism (5) comprising: a first catch (15A) movable between an engaged position in which the first catch (15A) is engagable with a furniture part (2) to retain the furniture part (2) and a release position in which the first catch (15A) is releasable from the furniture part (2); a second catch (15) moveable between an engaged position in which the second catch (15) is engagable with another furniture part or the same furniture part (2) to retain that furniture part and a release position in which the second catch (15) is releasable from that furniture part (2); and a locking mechanism (22) to lock the second catch (15) being lockable in the release position.

Description: THIS INVENTION relates to a mounting mechanism for securing a furniture leg to a piece of furniture, particularly a table or for securing two pieces of furniture together. Detachable legs for pieces of furniture are generally fixed to the furniture by complicated means and often require tools to attach and detach the leg to and/or from the furniture. When a conference/meeting table is to be left in situ for a long period of time in a "permanent" configuration, there is no need to provide a mounting mechanism which allows easy detachment of the legs from the table. However, it is advantageous to supply furniture such as tables in a flat-pack form to minimise carriage costs. Thus, it is still important for the legs to be easily attachable. Further, by providing an easy attachment or mounting mechanism, the initial construction' of the table need not require the presence of skilled personnel. Accordingly, this invention seeks to provide a mounting mechanism for securing a furniture leg to a piece of furniture, which mechanism does not suffer from the above disadvantages and which provides a solid attachment between a furniture leg and the piece of furniture, the leg being easy to attach and detach without the use of tools. Conference/meeting tables which comprise smaller tables which are linked or ganged together often need to be reconfigured to provide appropriate seating plans. Additionally, the number of people wishing to sit at the conference/meeting table will vary so the configuration of the table will need to be altered to accommodate such varying numbers. Accordingly, it is necessary for the smaller tables making up the conference /meeting table to link together in a number of configurations. It is known to provide a furniture leg which gangs together two table tops thereby reducing the number of legs required to support the composite conference/meeting table. However, when such a composite table is being dismantled, it is necessary to release all the links to one table top simultaneously to allow removal of that table top from the composite table. At least two people are required to perform this operation. To attempt to dismantle such a table single-handedly is fraught with difficulties, if not impossible. DE-U-9304661.8 discloses a connecting mechanism for attaching a table leg to one or more table tops. The connecting mechanism comprises a mounting bracket mountable on the leg, the assembled parts than being connectable to a mounting plate on the table. Another aspect of the present invention seeks to provide a detachable furniture leg having a mounting mechanism for securing table tops or the like together which overcomes the above disadvantages and which provides a solid and strong attachment between, for example, two table tops. Accordingly, the present invention provides a detachable furniture leg having a mounting mechanism comprising: a first catch movable between an engaged position in which the first catch is engagable with a furniture part to retain the furniture part and a release position in which the first catch is releasable from the furniture part; a second catch moveable between an engaged position in which the second catch is engagable with another furniture part or the same furniture part to retain that furniture part and a release position in which the second catch is releasable from that furniture part; and a locking means to lock the second catch in the release position. In order that the present invention may be more readily understood, embodiments thereof will now be described, by way of example, with reference to the accompanying drawings in which: Figure 1 is an isometric view showing a composite conference table comprising four main table tops and four corner pieces linked together in a "race-way" configuration, one corner piece of the table being shown removed from the table; Figure 2 is an exploded isometric view of the components of a mounting mechanism embodying the present invention together with the components comprising an adjustable height furniture leg; Figure 3 is an enlarged view of the mounting mechanism shown in Figure 2; Figure 4 is an isometric view showing the mounting mechanism of Figure 3 in an assembled condition, the mounting mechanism being mounted to a first mounting plate and in a position to be mounted to a second mounting plate; Figure 5 shows the mounting mechanism of Figures 2, 3 and 4 attached to a first table top, a second table top being shown in a lifted condition; Figures 6, 7 and 8 are schematic cross-sections through the mounting mechanism along the line VI-VI; Figure 9 is a perspective view of a transit leg embodying another aspect of the present invention; and Figure 10 is a side view of a part of the transit leg of Figure 9, part of a plunger and part of a push button being shown in phantom. Referring to Figure 1, a conference/meeting table 1 or the like comprises four rectangular main table tops 2 and four corner pieces 3 which link the respective table tops 2 together. Rather than providing the main table tops 2 and the corner pieces 3 with separate table legs, a single pair of table legs 4 are provided where the main table tops and the corner piece 3 abut one another. Each of the legs 4 is joined to the table top 2 and corner piece 3 by a mounting mechanism 5 embodying the present invention. The legs 4 extend downwardly from the mounting mechanism 5. A pair of mounting mechanisms 5 thus gang together each main table top 2 to a corner piece 3. A table leg 4 is shown in more detail in Figure 2. The leg 4 comprises two separate units, the mounting mechanism 5 and a table leg element 6 which is shown in Figure 2 as being height adjustable. The mounting mechanism 5 locks onto two mounting plates 7 (shown in Figure 4). One mounting plate 7 is fixed to the underside of the table top 2 and the other identical mounting plate 7 is fixed to the underside of the corner piece 3. The mounting plates 7 will be described later in more detail. The mounting mechanism 5 comprises a hollow housing 8 for receiving the working parts of the mounting mechanism 5. The housing 8 is an oval cylinder provided with a cover plate 9 at the furniture end of the housing 8 to close that end. The cover plate 9 is generally triangular in shape. The corners of the triangle are rounded to conform to the shape of the housing 8. The cover plate 9 is formed with two holes 10, 11, the function of which will be explained later. The opposite end of the housing 8, the open end, is formed with two cut-out portions. The table leg element 6 comprises an elongate cylinder 40 of generally oval cross-section corresponding to the cross-section of the oval cylinder of the housing 8. The cylinder 40 is shown in phantom in Figure 2. One end of the cylinder 40 acts as a sleeve to receive the open end of the housing 8. The outer surface of the housing 8 is provided with a step 41 to seat the housing on the elongate cylinder 40. The portion of the housing 8 below the step 41 is received in the cylinder 40 with an interference fit so that the housing is secured in the cylinder 40. A solid oval foot 42 is provided at the other end of the cylinder 40. A threaded rod 43 extends vertically up through the cylinder 40. A wheel 44 with a threaded bore 45 is fitted on a free end 46 of the rod 43. The wheel 44 and a portion of the rod 43 are sandwiched between the two halves of a plastics insert 46,46A. The inserts 46,46A are wedged in the cut-out portions of the housing 8. The inserts 46,46A are each formed with an aperture 47 to allow access to the wheel 44 so that the wheel 44 is rotatable in the inserts 46,46A. Rotation of the wheel 44 causes the rod 43 to be raised or lowered with respect to the inserts 46,46A and the cylinder 40 thereby raising or lowering the foot 42. Rotation of the wheel 44 thereby adjusts the height of the leg element 6. The mounting mechanism 5 includes two separate mounting plungers 12,12A which are pivotally attached to the inside side walls of the housing 8 by respective pins 13,13A in a generally upright position. The upper part of each plunger 12,12A i.e. above the pins 13,13A in a generally upright position is formed with a necked portion 14,14A which terminates in a conical catch head 15,15A. The lower half of each plunger 12,12A, i.e. below the pin 13,13A is provided with a vertically extending slot 16,16A. The conical catch heads 15,15A of the two plungers 12,12A extend through respective ones of the two holes 10, 11 formed in the cover plate 9. The holes 10,11 in the cover plate 9 define between them a spacing position 17 of the plate 9 which determines a rest position of the plungers 12,12A. The necked portion 14 of the plunger 12 extending from the pin 13 to the conical catch head 15 retains one end of a tension spring 18. The other end of the tension spring 18 is looped around the necked portion 14A of the other plunger 12A. The two conical catch heads 15,15A are therefore biased towards one another into the rest position but are prevented from coming into contact with one another by the spacing portion 17 of the cover plate 9. A push button 19,19A is attached to each plunger 12, 12A at a point below the pin 13,13A of the respective plunger 12,12A. The push buttons 19,19A extend out of two apertures provided on either side of the housing 8 so that the push buttons 19,19A are accessible from outside the housing 8. The push buttons 19,19A are operable to push selectively on one of the plungers 12,12A to pivot the selected plunger from the rest position in which it abuts the spacing portion 17 to a so-called 'release' position. When moving from the rest position to the release position, the plungers 12,12A move away from the spacer 17. Referring to Figures 2 and 3, a rocking latch 20 is provided below the pins 13,13A of the plungers 12,12A and is itself pivotally mounted on the inserts 46,46A held in the housing 8 by another pin 21. The rocking latch 20 extends substantially horizontally either side of the pin 21. One end 22 of the rocking latch 20 which is received in the vertically extending slot 16 is provided with a curved cam surface 23. The curved cam surface 23 contacts the lower edge of the vertically extending slot 16 in the plunger 12. The curved cam surface 23 of the rocking latch 20 terminates in a hook portion 24. When the plunger 12 is moved from the rest position to the release position, the hook portion 24 locks over and onto the lower edge of the slot 16 thereby locking the plunger 12 into the release position. An aperture 48 is formed in the rocking latch 20 so that the threaded rod 43 running through the leg element 6 can pass through the latch 20. When the leg 4 is fully assembled, the rod 43 passes from the foot 42, along the main body of the cylinder 40, through the aperture 48 in the rocking latch 20 which is pivotally mounted on the inserts 46, 46A. The rod 43 passes through the semicircular cut-outs in the inserts 46,46A, and the threaded bore 45 in the wheel 44. The other end 25 of the rocking latch 20 which is received within the vertically extending slot 16A in the other plunger 12A has a straight cam surface 26. The straight cam surface 26 abuts an upper edge of the slot 16A. When the plunger 12A is moved from the rest position to the release position by depressing the push button 19A, the upper edge of the slot 16A slides along the straight cam surface 26 to cause the end 25 of the rocking latch 20 to depress and the other end 22 to raise. If the hook portion 24 is locking the plunger 12 into the release position, then the lifting of the end 22 causes the hook portion to unhook from the lower edge of the slot 16 to unlock the plunger 12. The rocking latch 20 is biased into a position such that the curved cam surface 23 contacts the lower edge of the slot 16 and the straight cam surface 26 contacts the upper edge of the slot 16A. The rocking latch 20 is so biased by a torsion spring 27 which is fitted around the pin 21 of the rocking latch 20 and has two ends which hook over the lower edge of the rocking latch 20. The mechanism housing 8 is provided with a kinked tongue portion 28 which extends past and projects above the cover plate 9. The tongue portion 28 is engageable in an elongate slot 29 formed in the mounting plate 7 which is fixed to the underside of the table top 2. The mounting plate 7 is countersunk into a recess in the underside of the table top 2 or corner piece 3 so that the table tops 2 or corner pieces 3 can be stacked on top of one another without there being a risk of the mounting plates 7 scratching the top surfaces of the table tops or corner pieces. The tongue portion 28 is locatable in the elongate slot 29 in the mounting plate 7 such that the cover plate 9 can be rotated into a position parallel with and adjacent to the mounting plate 7. The conical catch head 15A of the plunger 12A adjacent to the tongue portion 28 thereby engages with a hole 30 provided in the mounting plate 7. A sloped surface 31A of the conical catch head 15A acts as a cam surface against the edge of the hole 30 thereby pivoting the plunger 12A about the pin 13A against the force of the tension spring 18 to allow the conical catch head 15A to be inserted in the hole 30. As soon as the widest portion, the base 32, of the conical catch head 15A passes through the hole 30, the plunger 12A is snapped back into its rest position by the tension spring 18 provided between the two plungers 12,12A. The base 32 of the conical catch head 15A thereby sandwiches the mounting plate 7 between itself and the cover plate 9 thus engaging and retaining the mounting plate 7 to provide a secure and strong attachment between the table top 2 and the mounting mechanism 5. The rest position is also termed the engaged position to denote the securing function provided by the plungers 12,12A. As shown in Figure 4, the other plunger 12 remains exposed. A second table top 2 with another identical mounting plate 7 attached thereto is lowered onto the mounting mechanism 5 causing the sloped surface 31 of the conical head catch 15 of the exposed plunger 12 to engage in the hole 30 in the mounting plate 7 to lock the exposed plunger 12 to the mounting plate 7 in a similar manner to the other plunger 12A. Thus, the exposed plunger is also able to engage and retain a mounting plate 7 to provide a secure and strong attachment between the table top 2 and the mounting mechanism 5. In this manner two table tops 2 are ganged together by a single mounting mechanism 5 embodying the present invention. The mounting mechanism 5 also provides means for releasing the mechanism 5 from a selected one of the two mounting plates 7 and hence, for example, from a selected table top 2. Referring to Figure 4, as well as being able to gang two table tops 2 together using the two mounting plates 7, the mounting mechanism 5 is also attachable to a single table top 2. For attachment to a single table top, the tongue portion 28 is located in the slot 29 in the mounting plate 7 in the opposite sense to that shown in Figure 4. In this manner, the plungers 12,12A engage in two respective holes 30',30" in the mounting plate 7 thereby attaching the mounting mechanism 5 to the single mounting plate 7. Referring to Figures 6, 7 and 8, these show a schematic version of the workings of the mounting mechanism 5. In these figures, the functions of the lower edge of the slot 16 and the upper edge of the slot 16A are replaced by a respective pin 33,33A on each of the plungers 12,12A. Figure 6 shows the plungers 12,12A in the rest or engaged position. In this position the conical catch heads 15 are locked onto the two mounting plates 7 which are shown in phantom. To release a corner piece 3 from the mounting mechanism 5, the push button 19 is depressed as shown in Figure 7. The plunger 12 thereby moves from the rest to the release position. As previously explained, the hook portion 24 locks the plunger 12 into the release position. Referring back to Figure 1, it can thus be appreciated that by depressing all the push buttons 19 of the mechanisms 5 locking a particular corner piece 3, that corner piece 3 is unlocked from the other table tops 2. Because the plungers 12 are all locked into the release position, the corner piece 3 is easily removed by a single person. It should be noted that releasing the corner piece 3 does not cause any of the table tops 2 adjacent that corner piece to be released. To release an adjacent table top 2, the other push button 19A associated with the other plunger 12A is depressed. This moves the other plunger 12A from its rest or engaged position to its release position as shown in Figure 8. By depressing the push button 19A, the rocking latch 20 is pivoted to raise the end 22 to unlock the hook portion 24 from the plunger 12 which is allowed to return to its rest or engaged position. The mounting plate 7 is fixed to a piece of furniture by way of fastening elements such as screws or the like which are received in fixing holes 34 formed around the periphery of the mounting plate 7. One consideration when fixing a mounting plate 7 to a piece of furniture is that it must be possible to insert the tongue portion 28 of the catch plate 9 through the elongate slot 29 in the mounting plate 7 without interfering with the piece of furniture upon which the mounting plate 7 is to be mounted. Further, the recess in which the mounting plate 7 is secured must provide sufficient clearance for the conical catch head 15 to prevent any interference with the working action of the conical catch head 15. Therefore, appropriate portions of the furniture are cut away or spacer washers (not shown) may be provided between the mounting plate 7 and the furniture to provide such clearance space between the furniture and the mounting plate 7. It is envisaged that the mounting plate 7 may be formed integrally with the table top 2 or corner piece 3. Another aspect of the present invention provides a transit leg comprising: a leg portion having a foot at one end for resting on a floor surface and a catch part at the other end which is operable to engage with a furniture part to retain the furniture part, the catch part being movable between a locking position in which the catch part locks onto the furniture part and a release position in which the catch part is releasable from the furniture part, the catch part being biased into the locking position. A further aspect of the present invention provides a detachable leg for furniture comprising: an elongate leg portion having a foot at one end for resting on a floor surface and a catch part at the other end which is operable to detachably engage with a furniture part to retain the furniture part, the leg being longitudinally extensible to adjust the height of the furniture part. Figure 9 shows a transit leg 100 embodying these two aspects of the present invention. The transit leg 100 comprises an elongate hollow aluminium extrusion 101 having a generally oval cross-section as seen in Figure 9. One end of the extrusion 101 houses a plastics moulded foot 102 for resting on a floor surface. The foot 102 is height adjustable with respect to the extrusion 101. The other end of the extension 101, the furniture end, is provided with a mounting mechanism 103 similar to that previously described with reference to Figures 2, 3 and 4. Unlike the previously described mounting mechanism, this mounting mechanism is provided with only a single pivotally mounted plunger 104. The plunger 104 is movable between an engaged position in which a catch part 105 of the plunger engages with and is retained by the furniture part and a release position in which the catch part is releasable from the furniture part. The plunger 104 is biased into the engaged position by a tension spring 106 (shown in Figure 10) which is fixed between the plunger 104 and an inner wall of the extrusion 101. As shown in Figure 10, the lower part of the plunger 104 below the point at which the plunger 104 is pivotally mounted is provided with a push button 107. The push button 107 projects through an aperture in the extrusion 101. When the push button 107 is depressed, the plunger 104 is pivotted from the engaged position to the release position. Preferably, a channel 108 is formed along the length of the extrusion 101. The channel 108 may receive telephone or power supply wiring. A further aspect of the present invention provides a mounting mechanism comprising: a first catch movable between an engaged position in which the first catch is engageable with a furniture part to retain the furniture part and a release position in which the first catch is releasable from the furniture part; and a second catch movable between an engaged position in which the second catch is engageable with another furnitue part or the same furniture part to retain that furniture part and a release position in which the second catch is releasable from that furniture part. A mounting mechanism embodying this aspect of the present invention comprises the mounting mechanism shown in Figure 3 but omitting the rocking latch 20 therefrom. Accordingly, the two plungers 12,12a are no longer mechanically linked except by the tension spring 18 which biases both plungers 12,12a into the engaged position.

Claims: A detachable furniture leg (4) having a mounting mechanism (5) comprising: a first catch (15A, 12A) movable between an engaged position in which the first catch is engagable with a furniture part (2) to retain the furniture part and a release position in which the first catch is releasable from the furniture part; a second catch (15, 12) moveable between an engaged position in which the second catch is engagable with another furniture part (2, 3) or the same furniture part (2, 3) to retain that furniture part and a release position in which the second catch is releasable from that furniture pail; and a locking means (24) to lock the second catch in the release position. A leg according to Claim 1, wherein the first and second catches are biased into the engaged position. A leg according to Claim 1 or 2, wherein a latch (20) is provided which mechanically interconnects the first and second catches. A leg according to Claim 3, wherein the latch includes the locking means which comprises a hook portion (24) which is engagable with and lockable to the second catch to lock the second catch is moved from the engaged position to the release position. A leg according to Claim 4, wherein the latch is provided with a cam surface (26) engagable with the first catch, movement of the first catch with respect to the latch effecting movement of the hook portion to unlock the hook portion from the second catch. A leg according to any preceding Claim, wherein the first and second catches are pivotally mounted on a housing (8) of the mounting mechanism and a latch is provided which is also pivotally mounted on the housing, which latch has one end engagable with the first catch and another end engagable with the second catch. A leg according to Claim 6, wherein the latch is biased to engage with the first catch. A leg according to any preceding claim, wherein the first and second catches are biased towards one another by a resilient member (18). A leg according to Claim 8, wherein the resilient member is a tension spring (18). A leg according to any preceding claim, wherein a mounting plate (7) is provided for attachment to a furniture part, the mounting plate having a slot (29) for receiving a tongue portion (28) of the mounting mechanism, a first hole (30") for receiving a part (15A) of the first catch and a second hole (30') for receiving a part (15) of the second catch. A leg according to any one of Claims 1 to 9, wherein a first mounting plate (7) is provided for attachment to a furniture part, the first mounting plate having a slot (29) for receiving a tongue portion (28) of the mounting mechanism and a first hole (3) for receiving a part of the first catch and a second mounting plate (7) is provided for attachment to another furniture part, the second mounting plate having a hole (30) for receiving a part of the second catch. A leg according to Claim 10 or 11, wherein the slot (29) and the tongue portion (28) co-operate to function as a hinge. A leg according to any one of Claims 10 to 12, wherein the or each mounting plate is formed inegrally with the or each furniture part. A leg according to any one of Claims 1 to 13, wherein the leg has an elongate leg portion (6) having a foot (42) at a lower end for resting on a floor surface and a catch part (15, 15A) at an upper end which is operable to detachably engage with a furniture part (2, 3) to retain the furniture part, the leg being longitudinally extensible to adjust the height of the furniture part, adjustment means (44) being located adjacent the upper end of the leg and operable to adjust the length of the leg. A leg assembly for detachably interconnecting furniture parts comprising: an elongate leg portion having an upper end and a lower end having a foot for supporting the leg assembly on a floor surface; and a mounting mechanism including: a tongue portion; a first catch movable between an engaged position in which said first catch is engageable with a first furniture part to retain the first furniture part, and a release position in which said first catch is releasable from the first furniture part; a second catch movable between an engaged position in which said second catch is engageable with a selected one of the first furniture part and a second furniture part to retain the same, and a release position in which said second catch is releasable from the selected one of the first and second furniture parts; and a locking means to lock the second catch in the release position, a first mounting plate being provided for attachment to the first furniture part, the first mounting plate having a slot for receiving the tongue portion of the mounting mechanism, a first hole for receiving a part of the first catch and a second hole for receiving a part of the second catch in a first configuration of the mounting mechanism and a further hole for receiving a part of the first catch in a second configuration of the mounting mechanism, a second mounting plate being provided for attachment to a second furniture part, the second mounting plate having a hole for receiving a part of the second catch in the second configuration of the mounting mechanism.

Inventors: CARR ROGER, PLANT RUSSELL, WILLIAMS DAVID, CARR, ROGER, PLANT, RUSSELL, WILLIAMS, DAVID
Applicants: STEELCASE INC, STEELCASE INC.
Application year: 1996
Main classification: F16B12
IPC codes: A47B13, A47B87