Drawer slide and drawer incorporating quick-release connection

A drawer slide and drawer slide combination which incorporates a connecting clip for providing a quick-release connection between the drawer slide 3 and the drawer 21 the clip comprising a fixing part 1 for connection preferably with a snap-fit, and preferably to the slide and a latching part 13 having a projection 17 thereon, preferably for engagement with an aperture 19 in the drawer 21. The latching part 13 is preferably spring loaded and preferably pivotable between a first aperture engaging position for connecting the drawer to the slide and a second release position in which the projection 17 no longer engages in the aperture in the drawer, whereby the drawer and slide can be disconnected. Disconnection is achieved by applying finger pressure to a release latch portion 15, which may be integral with the latching part 13. The connecting clip could be made of spring metal, but is preferably made of resiliently deformnable plastics material. It may be formed in one or in two parts.

FIELD OF THE INVENTION
 This invention relates to a drawer slide and drawer incorporating a
 quick-release connection between the drawer slide and the drawer.
 Nowadays, office furniture and the like which incorporates one or more
 drawers normally has each drawer mounted within a frame by means of a
 drawer slide so as to reduce friction and hence, wear between the drawer
 and the frame. Drawer slides are well known and comprise at least two
 longitudinally extending members, slidable relative to one another, there
 usually being a plurality of ball bearings arranged between the two
 relatively slidable members. In the past, one of the relatively slidable
 members has been fixedly secured to the frame, whereas the other has been
 secured to the drawer. It is preferred, however, nowadays that instead of
 fixedly securing one of the members to the drawer, some form of releasable
 coupling is provided so that the drawer can simply be removed from the
 frame and furthermore, so that the drawers are easily assembled within the
 frame.
 A quick-release connecting clip of the above type is known in which a
 deformed spring steel clip has one end connected by riveting to the slide,
 and the other, kinked end terminates in a step so as to provide a
 projecting nose engageable within an aperture in the side wall of the
 drawer. This aperture in the side wall is spaced somewhat rearwardly from
 the front of the side wall. This construction of connecting clip suffers
 from the disadvantage that it is made of spring steel and has to be
 pre-connected to the slide. Furthermore, because of the construction of
 the clip, it is possible for the clip to become disengaged from the
 aperture within the side wall of the drawer when, for example, the drawer
 is opened quickly and reaches the end of its travel. If the drawer is full
 of papers, it will be extremely heavy and substantial forces will be borne
 by the clip, which can cause the clip to deform and become disengaged from
 the drawer.
 In another known arrangement, two clips are provided, one being located
 between the drawer front and front of the drawer slide to provide a
 vertical latch, and one between the top of the slide and the drawer to
 provide a fore and aft latch. Such a double clip arrangement has its
 obvious disadvantages.
 The present invention seeks to provide an improved design of drawer slide
 and drawer, with a quick-release connection between the drawer slide and
 drawer, which is relatively simple to manufacture and fit, and is thus
 inexpensive.
 SUMMARY OF THE INVENTION
 According to the present invention, we provide a drawer slide and drawer
 combination incorporating a quick-release connection between the drawer
 slide and drawer, the combination comprising a drawer, at least one drawer
 slide comprising at least two slide members slidable relative to one
 another, an external one of said members being connectable to a framework
 and an inner one of said members being connectable to the drawer and a
 clip having a fixing part by means of which it may be connected to one of
 the inner slide member and the drawer, and a latching part having a
 projection thereon for engagement within an aperture or recess in the
 other of the inner slide member and the drawer, the latching part being
 moveable between a first position in which the projection engages with the
 aperture or recess to connect the drawer to the inner slide member and a
 second position in which it is disengaged from the aperture or recess to
 allow disconnection of the drawer from the inner slide member, there being
 means on or able to act on the latching part to enable the part to be
 moved between its first and second positions, and wherein the co-operation
 between the projection and the aperture or recess is such as to provide
 both vertical and fore-and-aft latching, and including further
 co-operating means on the drawer and drawer slide to hold the side of the
 drawer closely adjacent to the side of the slide.
 In one construction, the clip is formed of two separate parts, one
 comprising the fixing part, and the other comprising the latching part,
 which may be spring loaded; in this construction, co-operating means are
 provided on each part to assist in holding them together in use, with the
 spring bias to the latching part being provided by a leaf spring portion
 on the fixing part, and the latching part being held in position, in use,
 by being sandwiched between the fixing part and the one of the inner slide
 member and the drawer to which the fixing part may be connected.
 In another construction, the clip is a single moulded part which preferably
 incorporates a spring bias to the latching part provided by moulding the
 latter in a material which is resiliently deformable with a set, whereby
 when relaxed, it will take up its first position.
 Preferably, there is a stop on the clip which prevents the latching part
 being moved through more than a few degrees when it is moved to its second
 position.
 Preferably, the projection has thereon two chamfered surfaces arranged at
 right angles to one another. This assists in connecting the drawer to the
 slide by permitting fitting either from the front or from above.
 Preferably, the slide is adapted to receive the fixing part of the
 connecting clip with a snap fit and the drawer has an aperture therein
 into which the projection on the latching part is spring biased to connect
 the drawer to the slide.
 Preferably hook means is provided at a rear end of the slide which engages
 with a rear end of the drawer to prevent relative up and down movement
 between the drawer and slide at the rear of the drawer.
 Preferably, the co-operating means comprise a projecting nose at the front
 end of the slide which engages within a recess, provided by a lancing or
 by an aperture, in the front of the drawer. In this way, the drawer is
 positively located alongside the slide, thus ensuring that twisting of the
 drawer relative to the slide is avoided. This means that any forces
 between interengaged drawer and slide which are accommodated by the
 connecting clip are shear forces. This allows the clip to be manufactured
 from plastics material which is relatively strong in shear. This also
 means the clips can be manufactured by a moulding process.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT:
 Referring to the drawings, the clip shown in FIGS. 1 and 2 is moulded from
 plastics material in one piece and has a fixing part 1 for location within
 an inner slide member 3 of a drawer slide S. The drawer slide 5 is of
 generally known construction with the inner slide member 3 being slidable
 relative to one or more further slide members, there being a plurality of
 ball bearings located between the respective members. An outer slide
 member (not shown) is connectable to a framework for the drawer. The inner
 slide member 3 has a generally C-shaped cross-section, as shown in FIG. 8
 and the fixing part 1, as is apparent from the drawings, is shaped to form
 a snap-fit therein. However, it is not essential that it forms a snap-fit
 therein, and alternative methods of attaching the clip to the slide member
 3 (or it the drawer) will be apparent to those skilled in the art. A
 strengthening rib 9 extends throughout a major part of the length of the
 fixing part 1 and projecting outwardly from the strengthening rib 9 is a
 stop 11. The clip also comprises a spring-loaded latching part 13 which is
 connected to the fixing part 1 at is upper end, the profile of its upper
 end matching that of the fixing part 1. The part 13 is longer than the
 part 1 and is moulded so as to have a permanent set which causes the part
 13 to lie in a different plane from the part 1, the two planes making an
 angle of a few degrees with one another. At is lower end, the
 spring-loaded part 13 terminates in a release latch portion 15, whereby by
 pressing ones finger against said portion 15, the part 13 can be moved
 against the bias provided by its permanent set so as to move it into and
 beyond the plane of the fixing part 1, until it engages the stop 11.
 Projecting from the face of the spring-loaded part 13, opposite the face
 of the fixing part 1 from which the strengthening rib and stop 11 project,
 is a projection 17 for engagement within an aperture 19 in the side wall
 of a drawer 21. The projection 17 has a first chamfer 23 on its front edge
 and a second chamfer 25 on its top edge. These allow the projection 17
 easily to enter the aperture 19 when the drawer is offered up onto the
 slide either from above or from the front thereof The permanent set or
 spring bias of the spring-loaded part 13 is such that when the drawer 21
 and the drawer slide 5 are assembled together, the projection 17 will
 automatically be biased into snug engagement within the aperture 19. The
 side face of the projection opposite the chamfer 23, and its lower face,
 are square latching faces.
 As can be seen from FIGS. 6-8, when the drawer 21 and drawer slide 5 are
 assembled together, they are held in close side-by-side relationship by
 virtue of a nose or tongue 27 on the front end of the drawer slide 5
 engaging in an aperture provided by a lancing 29 in the front of the
 drawer.
 Referring now to FIGS. 3-5, the two-piece connecting clip, when assembled
 and in use is very similar in construction to the one-piece clip of FIGS.
 1 and 2. The two-piece clip is formed from two moulded parts 31, 33. The
 part 31 incorporates a fixing part 1 identical to that of the one-part
 version which incorporates a strengthening rib 9 and a stop 11. However,
 instead of a spring-loaded part 13, it is provided with a biasing arm 12,
 which cooperates with the second part 33. The second part 33 has a
 latching arm 14 which is generally of a similar shape to the spring-loaded
 part 13 of the one-piece construction and which has an identical
 release-latch portion 15 and projection 17 incorporated thereon. At its
 upper end, the aim 14 has a generally cruciform portion 16, by means of
 which the part 33 can be connected to the part 31. To enable the two parts
 to be held together, the part 31 has two projecting lugs 18 thereon which
 engage within the recesses 20 formed between the cruciform portion 16 and
 top of the arm 14. As can be seen from FIG. 5, when the two parts 31 and
 33 are assembled, the biasing arm 12 on the first part 31 will be located
 behind the arm 14 on the part 33 and because the biasing arm 12 has a
 permanent set, as is the case with the springloaded part 13 in the
 one-piece construction, the arm 14 will take up a similar position
 relative to the fixing part 1 in the two-piece construction, as is the
 case in the one-piece construction. The two-piece construction of
 connecting clip is assembled into the slide member 3 of the drawer slide 5
 in the same manner as the one-piece construction and once assembled, the
 two parts are held together.
 To assemble a drawer with the drawer slide and connect the two together,
 the one or two-piece connecting clip is first of all located within the
 slide member 3 of the drawer slide with its spring-loaded latching part 13
 or latching arm 14 abutting the flat inside face of the slide member 3 and
 the projection 17 extending through an aperture or slot (not shown)
 therein. In practice, there will, of course, be two drawer slides, one for
 each side of the drawer with the respective slide members 3 facing one
 another and each will be provided with a connecting clip having its
 projection 17 extending outwardly through the aperture in the slide member
 3 so as to project beyond the outside face of the slide. A drawer 21 is
 then placed over the two drawer slides and its rear end is slid back over
 the drawer slides until a rear end thereof comes into engagement with a
 hook on the rear of the slide. This hook engages in a recess provided for
 the purpose in the rear of the drawer so as to provide a vertical location
 for the rear of the drawer. The drawer can be connected to the drawer
 slide by a simple snap-fit, either by pushing the drawer downwards
 relative to the drawer slide, if it is slightly raised, or alternatively,
 by pushing it rearwards if it is perfectly in line. The presence of the
 drawer alongside the drawer slide will cause pressure to be applied to the
 projection 17 on each connecting clip, thus moving either the release
 latch portion 15 in the case of the one-part construction, or the arm 14
 in the case of the two-part construction, against its spring bias until
 the aperture in the side wall of the drawer is aligned with the projection
 17 on the clip, whereupon the spring bias within the spring-loaded part 13
 or biasing arm 12 will cause the projection 17 to snap into the aperture
 in the respective side wall of the drawer 21. The drawer 21 and drawer
 slides 5 are then interconnected. Before this interconnection can occur,
 it is necessary for the nose or tongue 27 on the front edge of the drawer
 slide 3 to engage within its respective aperture, provided by the lancing
 29 on each side edge of the drawer 21. Once so engaged, the front end of
 each drawer slide is held closely alongside the side walls of the drawer
 21. This is important, because when the drawer is opened and is full, and
 the drawer slide reaches the forward most part of its extension
 capability, the momentum of a full drawer has to be absorbed almost
 completely by the connecting clips. If the slide member 3 of each drawer
 slide is held closely adjacent its respective drawer side wall, there is
 virtually no twisting of drawer relative to slide member 3 and this means
 that the forces acting on the connecting clips due to the momentum of a
 full drawer are taken almost completely as shear forces in the
 spring-loaded part 13 in the case of the one-piece clip, or arm 14, in the
 case of the two-piece clip. This means that the connecting clips can be
 moulded from plastics material which is strong in shear, but not in
 twisting.
 The above-described constructions of-quick-release drawer systems have the
 quickrelease connecting clips at the very front of the drawer and the
 drawer slides. This means that when it is desired to disconnect a drawer
 from its drawer slide, this is a very simple operation by the user
 applying finger pressure to the release latch portion 15 on the lower end
 of the spring-loaded part 13 (in the case of the one-piece clip) or the
 arm 14 (in the case of the two-piece clip). This will move the respective
 part 13 or 14 against its spring bias, thus moving the projection 17 out
 of the aperture. in the side wall of the drawer and allowing the drawer to
 be removed not only from its slide but also from the framework in which
 the whole mechanism is located. It should be appreciated, however, that it
 would be possible to locate the connecting clips further towards the rear
 of the drawers or even at the rear of the drawers. A further advantage,
 however, of having the clips at the front of the drawers is that they are
 easily accessible without having fully to open the drawers.
 It is an important feature of the present invention that the latching faces
 on the projection 17 and on the aperture 19 within the side walls of the
 drawer extend generally at right angles to the side walls of the drawer.
 This means that when a drawer is opened or closed and suddenly stopped,
 the forces between the drawer and its drawer slides are accommodated by
 these surfaces which are normal to the direction of movement of the
 drawer. This means that there is no twisting on the connecting clips which
 would otherwise tend to cause them to become disengaged. This is a major
 advantage of the clips of the present invention over the first mentioned
 prior art clip described above.
 It will, of course, be appreciated that the stop 11 on each construction of
 clip is provided to prevent the spring-loaded part 13 or the arm 14 being
 moved too far when release pressure is applied to the release latch
 portion 15.
 Although the clips of the present invention are preferably moulded from
 plastics material, they could be formed of a springy metal and have
 alternative constructions. One such alternative construction is shown in
 FIG. 9; this is a two-part construction comprising a first retaining part
 51 and a second release part 53. In this construction, the retaining part
 51 has upper and lower edge regions 55, 57, the free end portions of which
 engage behind the turned-over edge regions of the slide member 3. The
 first retaining part 51 has an extension arm 59 on an outer kinked end
 portion 61 of which is located a projection 63, equivalent to the
 projection 17. The second releasing part 53 is somewhat similar in
 construction to the spring-loaded part 13 or arm 14 and is located behind
 the extension arm 59 and provided with a release-latch portion 65,
 equivalent to the portion 15. As will be apparent from FIG. 9, by applying
 pressure to the release latch portion 65 in the direction of the arrow 67,
 pressure will be applied to the kinked end portion 61, so as to move the
 projection 63 in the direction of the arrow 67, thus allowing the
 projection 63, which is designed for engagement within an aperture in the
 side wall of the drawer, to be moved to a release position. It will, of
 course, be appreciated that the two-piece construction as shown in FIG. 1
 could be manufactured in one piece. This construction could be
 manufactured from plastics material, or from spring metal, or a mixture of
 the two.
 Furthermore, this construction could be made in one part by forming the
 releasing part 53 integral with the parts 57 and 59. In FIG. 10, a
 modified shrouded drawer 21a is shown, and thus differs from that of the
 other Figures in that it has a drawer shroud largely overlying the slide
 5, which is connected to the side wall of the drawer by a front wall. This
 has an aperture 29a therein, within which the nose 27a on the slide member
 3 engages.
 It will, of course, be understood that the present invention has been
 described above purely by way of example, and modifications of detail can
 be made within the scope of the invention.
 For example, it is not essential for the latching part 12 or arm 14 to be
 spring loaded. Instead, the latching part or arm could be constructed so
 as to engage with the aperture in the side wall of the drawer with an
 interference fit, so that it would effectively have to be snapped into
 latching engagement with, and out of latching engagement with the
 aperture. Furthermore, in the drawings, the latching part 12 (and arm 14)
 are shown of a construction which pivots into and out of latching
 engagement with the aperture in the side of the drawer. In a modified
 construction, movement into and out of engagement with the aperture could
 be achieved in a sliding manner.