EP0037257A1

EP0037257A1 - Drawer assemblies

Info

Publication number: EP0037257A1
Application number: EP81301309A
Authority: EP
Inventors: David Norman Harley
Original assignee: Titus Tool Co Ltd
Current assignee: Titus Tool Co Ltd
Priority date: 1980-03-28
Filing date: 1981-03-26
Publication date: 1981-10-07

Abstract

A drawer assembly (2) comprises a drawer (4) which is mounted for sliding movement on a pair of floating rails (18) which are themselves slidable with respect to the sides (8) of the housing (6) of the assembly (2). Each floating rail (18) slides in an elongate recess (16) in a respective side wall (12) of the drawer (4). The sliding movement is limited by the engagement of a drawer element (42) with the ends of a slot (40) in the rail (18). The element (42) can be pushed through a hole (44) in the side wall (12) of the drawer (4), through the slot (40), and then twisted to lock the rail (18) against lateral movement with respect to the drawer (4).

Each rail (18) is mounted for sliding movement with respect to the housing (6) on a pair of bearing elements (22) disposed inside the rail (18) and hence inside the recess (16) in the drawer side wall (12). The rail (18) is snap-fittable over flanges (38) on the bearing elements (22). Each of the bearing elements (22) is an integrally-formed unit.

Description

This invention relates to drawer assemblies, and particularly to assemblies for use in furniture.
Known drawer assemblies tend to be either expensive, or provide poor operation in terms of the friction encountered during opening and closing of the drawer and/or the extent by which the drawer can be opened. The mechanism by which the drawer is permitted to slide. during opening and closing is often bulky and difficult to assemble.
Some types of drawer assemblies have a "floating-support" arrangement, in which the drawer is supported for sliding movement on one or more "floating" members, the or each of which is itself slidable with respect to the housing of the assembly. In this way, when the drawer is opened, the drawer slides with respect to the floating member, and the floating member slides with respect to the cabinet, so that the drawer can be withdrawn to a much greater extent than would otherwise be possible
Such arrangements are very desirable in a number of circumstances, but tend to be much more expensive than more conventional arrangements, .and also to suffer much more from the disadvantages of high cost and difficult assembly. For example, the cabinet generally carries a pair of elongate rails which slidably support the floating members. These rails must be fairly long to provide stability and avoid tilting of the floating members and hence the drawer, and must also allow relatively friction-free sliding of the floating members, so that the rails are consequently quite expensive.
It is an object of the invention to provide a drawer assembly, preferably of the "floating-support" type, which is considerably less expensive than known assemblies of comparable performance, and which is less bulky and easier to assemble than such known assemblies.
According to one aspect of the invention there is provided a drawer assembly of the "floating-support" type, in which the drawer is supported by a pair of floating members, one on each side of the drawer. Each floating member is itself slidable with respect to a housing of the assembly, and is also slidable with respect to the drawer. The drawer has a pair of opposed side walls, the outer surfaces of which have elongate recesses extending in the direction in which the drawer is opened and closed, and each of the floating members is slidable in and along a respective one of the recesses.
The recesses provide a simple and convenient means for guiding the sliding movement of the drawer with respect to the floating members, and also enables a substantial reduction in the width of the sliding mechanism of the drawer assembly. Furthermore, by using an elongate floating member disposed in each recess it is possible to avoid tilting of the drawer with respect to the floating members.
Many drawers presently on the market include sidewalls which are provided with elongate recesses of a standard size and intended to permit the drawer to slide on fixed battens. Thus, it is possible for the floating member to be designed to fit into these standard grooves, as a result of which readily-available drawers designed for simple sliding movement on battens can instead be provided with a telescoping support arrangement using the -floating member. The floating member preferably has a shape and size conforming to that of the groove (which may if it is of standard size have a width of 17 mm). The recess could be formed by an intrusion in the side wall, so that the latter has an overall thickness which is reduced at the position of the groove. This could be achieved, for example, by cutting out a portion of a rectangular-section wall of, e.g. wood, or by extruding a wall (which may be solid or hollow) with an appropriate cross-sectional shape. Alternatively, the side wall could be contoured to provide a recess. This again could be achieved by an extrusion, or by the bending of a sheet- metal wall.
Preferably, the floating members have interior spaces in which are disposed supports for slidably supporting the floating members with respect to the cabinet. By disposing the supports inside the floating members, and hence inside the recesses, a further reduction in the width of the sliding mechanisms is achieved.
According to another aspect of the invention, one of a drawer-and a support for the drawer is provided with an elongate slot, in which an element of the other of the drawer and-the support for the drawer extends. Sliding movement.between the drawer and its support is limited by the engagement of the element with the ends of the slot. The.element can be twisted about its axis from a first position, in which it can be pushed through the slot, to a second position in which it engages the sides of the slot and thus prevents relative movement between the drawer and its support.
The slot is preferably in the above-mentioned floating member, which is itself slidable with respect to the housing of-the assembly. The slot may be in a vertical, surface of the floating member disposed at the base of the recess, in which case the element need not bear the weight of the drawer, which .can instead be supported by the. engagement of the upper wall of the recess with the upper wall of the floating member.
Using such an arrangement, assembly of the drawer can be made very easy. In a preferred embodiment, the element is pushed through a hole in the side of the drawer and then through the slot in the member, and then twisted so as to cause a laterally protruding portion at the end of the element to come into engagement with one or both sides of the slot, thereby fixing the drawer against lateral moyement.
Preferably the drawer is provided at each side with a flange which is snap-fittable over another flange fixed to the Housing of the assembly, the flanges permitting sliding movement therebetween during opening and closing of the drawer, but preventing lateral movement of the drawer with respect to the housing.
The snap-fitting engagement can be achieved by the flexing of either one or both of the flanges, and avoids the necessity of threading one of the flanges over the other. The drawer or the housing is preferably provided with a pair of upper and lower flanges which extend longitudinally of the drawer and which snap-fit onto a member of the housing or drawer, respectively.
The drawer flanges may in fact be provided on a floating member which is itself slidable with respect to the drawer. In this case the snap-fitting arrangement is particularly advantageous in that it enables the floating member to be formed with stops for limiting its sliding movement with respect to the housing of the assembly,and yet does not require removal of one or other of the stops for threading of the floating member onto the housing flange and later replacement of the stop.
Preferably the drawer, and if provided the floating members, are mounted on the housing by means of at least two independently mounted fixtures at each side of the drawer. Each fixture is preferably an integrally-formed unit. The independent mounting of the fixtures means that each such fixture can be relatively small and simple in construction, thus avoiding the need for a long expensive rail fixed to the housing at each side,. and also increases the versatility of the system as it permits variations in the mounting arrangement.
Preferably each fixture comprises a roller or wheel on a shaft which was originally formed integrally with the roller but later disconnected therefrom. Such a fixture, which may also incorporate a support-gripping.(e.g. Wood-gripping) portion for attachment to the support, can be produced easily and inexpensively, for example by injection moulding of plastics.
In a preferred arrangement, the fixture is originally formed in'such a manner that a blow on the fixture to disconnect the roller or wheel from the shaft results in the roller or wheel being rotatably positioned on the shaft. When the fixture is provided with a support-gripping portion, the arrangement is preferably such that this same blow also causes a support to be gripped by that portion.
The fixture may also have a flange for abutting the surface of a support into which it is fixed. It may also, or alternatively, have a flange for engagement with a member on an item to be supported by the fixture, to prevent relative movement between the item and the fixture in a direction transverse to the intended movement on the wheel or roller.
The invention thus provides a drawer assembly which is very inexpensive to make and very easy to assemble,. and has a very small number of components. The entire length of the drawer can be pulled out of the drawer support (e.g. a cabinet), and means are provided for positively stopping movement of the drawer at its forward and rear positions thereby to prevent damage and accidental removal.
An arrangement embodying.the invention.will now be described by way of example with reference to the accompanying drawings, in which:-

Figure 1 is a.perspective.view of a drawer assembly in accordance with the invention;
Figure 2 is an exploded perspective view showing a portion of a drawer of the assembly of Figure 1 with part of the support for the drawer;
Figure 3 is a vertical section through part of the drawer and the support;
Figures 4A to 4C are side views showing the drawer in various positions;
Figures 5A and 5B are, respectively, a side elevation partly in section and an end view of a bearing of the assembly of Figures 1 to 3;
Figures 6A to 6D show a further element of the assembly of Figures 1. to 3, Figure 6A being a plan view, Figure 6B an elevation, Figure 6C an end view and Figure 6D a section on the lines A-A of Figure 6A; and
Figure 7 is a section through an alternative form of bearing which can be used in the assembly of Figures 1 to 3.

Referring to Figures 1 to 3, the assembly 2 comprises a plurality of drawers 4 each of which can be slid in and out of a cabinet 6. The cabinet has a pair of side walls, one of which is indicated at 8, which support the drawers.
Each drawer has a front panel 10, a pair of side panels 12, a base 14 and a rear wall (not shown). Each sidewall has, on its outer face, an elongate, rectangular groove 16 extending from the front panel to the rear of the drawer. The groove is of a standand size used in many drawers presently on the market which are primarily intended to slide on battens located in the grooves and fixed to the side.walls.
The drawer is slidably supported on each side by a floating rail 18 which has a generally rectangular- cross section central portion 20 which fits in the rectangular groove 16. Each rail itself slides on a pair of wheel-bearing units 22 which are fixed on the inner side of the side wall 8, close to the front of the side wall. The units 22, which will be described in more detail later, each include a wheel or roller 24 which locates in the central portion 20 of the rail 18 for slidably.supporting the rail.
As the drawer.is pulled out (see also Figs. 4A to 4C), the rail 18 at each side slides on the rollers 24 until about.two-thirds of the drawer's length has been withdrawn, and thereafter the drawer itself slides on the rails 18 until the entire length of the drawer has . been withdrawn. Throughout this movement, each rail is supported on the rollers 24, and the drawer is supported at each side by the engagement of the upper wall of the groove 16 with the upper, generally horizontal wall 26 of the central portion 20 of the rail 18.
The rail 18 has upper and lower webs 28 and 30 which extend upwardly and downwardly from the top and bottom of the central portion 20, respectively. A flange.32 extends downwardly from the top of the upper web 28, and a flange 34 extends upwardly from the bottom of the lower web 30.
The roller unit 22 includes a pair of circular flanges 36 and 38. The flange 36 abuts the inner surface of the side wall 8, and the flange 38 is spaced therefrom. The upper and lower flanges 32 and 34 of the rail 18 locate between these circular flanges 36 and 38. The flange 38 thereby restricts lateral movement of the rail with respect to the side wall 8, and the flange 36 prevents the rail 18 from engaging the side wall, which may damage the side wall and increase the friction encountered in sliding of the rail.
The rail 18 has, in its front half,. an elongate slot 40.. An element 42 extends from the inside of the drawer through a hole 44 at the base of the groove 16 and thence through the slot 40 so that the sliding move- ment of the rail 18 with respect to the drawer is limited by the engagement of the element 42 with the front and rear ends of the slot 40. The element 42 is provided with-an elongate, laterally extending portion 46 which, in use, is located inside the central portion 20 of the rail 18, and which engages the upper and lower sides of the slot 40 to prevent lateral movement of the rail 18 with respect to the side panel 12 of the drawer 4.
Figures 4A to 4C illustrate how the various parts of the drawer assembly move as the drawer is opened. The movement of the rail 18 with respect to the side wall 8 is limited by front and rear stops 48 and 50 for engagement with the front and rear rollers 24. As mentioned above the sliding movement of the rail with respect to the drawer is limited by the engagement of the element 42 with the front and rear ends on the slot 40. The arrangement of the various components is such that, as illustrated in Figure 4C, the entire length of the drawer can be withdrawn from the side wall 8 (the front of which is indicated by the line 52).
The detailed construction of the bearing unit 22 will be described with reference to Figures 5A and 5B, which show the unit in its original, moulded form, . and Figure 3 which shows the unit in the form it has when it is in use.
The unit is injection moulded using engineering grade plastics, and incorporates a support-gripping base portion 54 which in this case is a wood-gripping portion provided with annular barbs to engage the wall of a hole 56 formedin the side wall 8. The portion 54 is connected to the flange 36, which is connected by a frusto-conical portion 58 to the flange 38. The unit also incorporates a shaft portion 60, a stop portion 62 having a frusto-conical outer surface,.and the roller 24 which has an inner shoulder defining a stop face 64. In the units original form, the roller 24 is linked to the stop portion 62 by a very thin annular connecting portion in the region indicated at 66.
To use the roller unit, a hole is drilled to receive the wood-gripping portion 54, and the unit is then located over the hole with the portion 54 lowermost. The top of the unit, i.e. the roller 24, is then subjected to a blow, e.g. by means of a hammer. This breaks the connection between the roller 24 and the rest of the unit, and forces the roller over the stop portion 62 onto the shaft portion 60, and at the same time bodily moves the entire unit so that the wood-gripping portion 54 enters the prepared hole. The roller unit is secured in position by the barbs on the wood-gripping portion 54, and the roller is prevented from coming off the shaft 60 by the engagement of the face 64 with the stop portion 62.
The rail 18 (including the stops 48 and 50) is an integrally formed piece made by bending sheet metal. The rail 18 could be threaded onto the bearing units 22 during assembly, but this would in any circumstances be awkward and in this particular case be very difficult as it would involve bending one of the stops 48 and 50 out of the way and then bending the stop back into its former position after the rail is located on the bearing unit. This is avoided by making the flange 38 of the bearing unit 22 flexible, so that the upper and lower flanges 32 and 35 of the rail 18 can be snap-fitted over the circular flange 38. The flange 38 has a frusto-conical outer surface to facilitate this.
Referring to Figures 6A to 6D, the element 42 comprises a flexible-domed head 70 (omitted from Figure 6D), a shaft portion 72, an elongate.member 74, and the protruding portion 46. The member 74 and the portion 46 both have a generally rectangular shape, the member 74 being slightly longer than the portion 46. In use, the element 42 is pushed through the hole 44, and, with the member 74 and portion 46 extending generally horizontally, the portion 46 is pushed through the slot 40 in the rail 18. The length of the member 74 is slightly greater than the diameter of the hole 44, but the member 74 can flex to permit it to pass through the hole. The shaft 72 is tapered as indicated at 75 to permit this'flexing. With the edges of the slot 40 lying between the portion 46 and the member 74, the entire element 42 is twisted through 90° so that the member 74 and portion 46 extend substantially vertically, and their upper and lower ends overlie the edges of the slot 40, which is gripped between the portion 46 and the member 74. The portion 46 and the member 74 are connected by a non-symmetrical (in this case square) part 76 having a configuration as shown in Figure 6D, which is such that an over-centre type of action is produced as the element 42 is twisted, so that the element is secured by the sides of the slot 40 in a locking position. This locks the rail 18 against lateral movement transverse to the length of the slot, but permits sliding movement, during which the edges of the slot 40 ride over the upper and lower sides of the connecting part 76.
The head 70 is provided with an elongate slot 80 in which a coin can be inserted to facilitate twisting of the element 42 The head 70 is flexible to permit variations.in the amount by which the element 42 is inserted through the hole 44; this allows for variations . in the thickness of the side panel 12 at the base of the groove 16.
The member 74 holds the rail 18 away from the bottom of the groove 16, so that there -is no frictional engagement therebetween and sliding movement of the drawer with respect to the rail is thus very smooth and free.
. Figure 7 shows-an alternative type of bearing unit which can be used in the drawer assembly. The unit is similar to that of Figures 5A and 5B, except that the unit can be rotated eccentrically with respect to the support-gripping portion 54 to permit variation in the effective height of the roller 24. The front portion of the unit 22, including the roller and the flanges 36 and 38, have a rearwardly-extending spigot 82 which is eccentrically mounted and which is rotatably supported in the wood-gripping portion 54. Thus, rotation of the unit with respect to the wood-gripping portion 54 will raise and lower the roller 24. A slot indicated at 84 may be provided to facilitate rotation. A ratchet-type movement may be provided for stepwise adjustment, and this could be achieved by having circumferentially- spaced ribs 86 on the spigot 82 engaging in circumferentially spaced recesses on the inner side of the wood-gripping portion 54. Alternatively, the ribs and recesses may be on the portion 54 and the spigot 82, respectively. The material from which the unit is made is resilient so that slight deformation occurs as the ribs are moved out of the recesses during turning of the unit, and the deformation is relieved as-the ribs enter different recesses after a stepwise rotation of the unit.
It is preferred that, as in the earlier embodiment, the wood-gripping portion 54 be formed integrally with the rest of the unit 22. This can be achieved by moulding the unit in such a manner that the portion 54 is initially connected to the spigot 82 by a very thin portion which is broken on rotation of the main body of the unit with respect to the portion 54.
The drawer assembly of the present invention is entirely non-handed, i.e. each component can be used either on the left-hand or the right-hand side of the drawer. This has advantages both in the manufacture and the stocking of components.
It will be appreciated that the total number of components used in the drawer assembly described above is very small. Only four components, each of which is an integrally-formed unit, are required at each side of the drawer.
The entire weight of the drawer is supported by bearing units 22 which are all located at the front parts of the side walls 8; this means that the rear parts of the side walls are not required for supporting purposes, but nevertheless the drawer is supported , firmly in such a manner that.there is little or no wobbling or. tilting.
In a modification of the arrangement described above, the elongate slot 40 is provided in the drawer side panel 12, rather than in the rail 18, and the element 42 is inserted through a hole in the rail 18 to grip the sides of the slot in the drawer.
The shape of the rail 18 can vary to suit the drawer, and the groove 16 is not essential: For example, the rail 18 could be L-shaped in.cross-section, and be arranged to support a lower edge of the drawer. The invention is also applicable to metal structures, such as filing cabinets, in which case the side walls of the drawers may be contoured to facilitate supporting of the drawers by the rails. The rails may be made of plastics to provide smoother sliding with respect to the metal drawings.

Claims

1. A drawer assembly comprising a drawer (4) having opposed side walls (12) by means of which the drawer (4) is mounted for sliding movement on a pair of intermediate members (18) which are themselves . mounted for sliding movement with respect to a support (6), whereby the drawer (4) can be opened and closed with respect to the support (6) by sliding the drawer (4) relative to the intermediate members (18) and the intermediate members (18) relative to the support (6), characterised in that each said side wall (12) has a recess (16) in which a respective one of said intermediate members (18) is at least partially disposed for sliding movement along the recess (16).

2. A drawer assembly as .claimed in claim 1, characterised in that each said intermediate member (18) has an elongate slot (40) in which an element (42) fixed to the drawer (4) is disposed so that sliding movement of the drawer (4) with respect to the intermediate members (18) is limited by the engagement of the elements (42) with the ends of the slots (40)..

3. A drawer assembly as claimed in claim 2, characterised in that each said element (42) has a portion (46) for engaging a side of the respective slot (40) to prevent relative lateral movement between the respective intermediate member (18) and the drawer (4).

4. A drawer assembly as claimed in claim 3, characterised in that each said element (42) is rotatable between a first position in which the element portion (46) does not engage the side of the slot (40) and relative lateral movement between the intermediate member (18) and the drawer (4) is permitted, and a second position in which the element portion (46) engages the side of the slot (40) to prevent said lateral movement.

5. A drawer assembly as claimed in claim 4, characterised in that each said element (42) is lockable in said second position by an over-centre type locking arrangement (76,40).

6. A drawer assembly as claimed in any preceding claim, characterised in that the weight of the drawer (4) is supported by the engagement of the intermediate members (18) with surfaces of the respective recesses (16).

7. A drawer assembly as claimed in any preceding claim, characterised in that each said intermediate member (18) is slidably mounted on the support (6) by at least two discrete, independently mounted support elements (22).

8. A drawer assembly as claimed in claim 7, characterised in that each said support element (22) is an integrally-formed unit and comprises a mounting portion (54) for engaging the support (6) and a supporting portion (24) for supporting the.respective intermediate member (18).

9. A drawer assembly as claimed in any preceding claim, characterised in that each said intermediate member (18) is mounted on the support (6) by mounting means (22) disposed in a space inside the intermediate member (18) and'hence at least partially inside a respective one of the recesses (16).

10. A drawer assembly as claimed in any preceding claim, wherein each said intermediate member (18) has a flange (32,34) which is snap-fittable over a further flange (38) fixed with respect to the support (6) to prevent lateral movement of the intermediate member (18) with respect to the support (6).

11. A drawer assembly,characterised in that a drawer (4) of the assembly (2)' is provided at each side with a flange (32,34) which is snap-fittable over a further flange (38) provided on a support (6), whereby the flanges (32,34,38) at each side of the drawer (4) prevent lateral movement of the drawer (4) with respect to the support (6) but permit sliding movement of the drawer (4) with respect to the support (6) for opening and closing the drawer (4).

12. A drawer assembly as claimed in claim 11, wherein each of said flanges (32,34) with which the drawer is provided is disposed on a respective intermediate member (18) which is slidable with respect to the drawer (4).

13. A drawer assembly comprising a support (6) and a drawer (4) which is slidable with respect to the support (6) for opening and closing the.drawer (4), the drawer (4) being slidably supported by a pair of supporting members (18) disposed one.at each side of the drawer (4), characterised in that, at each side of the drawer (4), either the supporting member (18) or the drawer (4) is provided with an elongate slot (40) in which is disposed an element (42) of the other of the supporting member (18) and drawer (4), so that during relatve sliding movement between the supporting member (18) and the drawer (4) the element (42) shifts along the slot (40), the element (42) being rotatable between a first position in which it can be moved laterally to extend through the slot (40) and a second position in which the element (42) engages a side of the slot (40) to prevent lateral movement between the supporting member (18) and the drawer (4).

14. A drawer.assembly as claimed in claim 13, characterised in that the supporting members (18) are slidable with respect to the support (6).