Three member thin drawer slide

A drawer slide assembly with an outer slide member with an elongate planar web including a parallel offset portion, having upper and lower bearing raceways along the length of the web, an intermediate slide member with a elongate planar web, having inner and outer upper and lower bearing raceways along the length of the web, and an inner slide member having an elongate planar web with upper and lower bearing raceways along the length of the web, with bearings disposed between and in rolling engagement with the respective outer and intermediate slide members, and intermediate and inner slide members.

BACKGROUND OF THE INVENTION

The present invention relates generally to drawer slides, and more particularly to telescopic drawer slides.

Drawer slides are often used to extendably couple drawers, trays, and rack-mounted equipment to cabinets, racks and the like. The drawer slides do so by having one elongate member coupled to the cabinet or rack, and another elongate member attached to the drawer or equipment. The elongate members are slidably coupled so as to be able to longitudinally extend with respect to one another. This extension allows easy access to the drawer or equipment.

One type of drawer slide is a telescopic drawer slide. A telescopic drawer slide generally has an outer somewhat C-shaped member. An inner member, also generally C-shaped, is generally largely nested within the outer member. At times, an intermediate member is placed between the outer member and the inner member. The inclusion of the intermediate member allows for increased extension of the drawer or equipment.

In some applications, ball bearings connect the slide members. The ball bearings are placed in raceways formed along the longitudinal edges of the slide members, and the bearings slidably, or rollably, connect the slide members. The use of ball bearings allows for a smooth and generally consistent action.

In many applications, particularly rack-mounted applications, the width of the drawer slide is of some importance. The use of drawer slides having a very thin width reduces the space taken up by the drawer slide, and allows equipment to be placed closer together, thereby allowing for more equipment to be mounted in a particular rack.

Decreasing the width of the drawer slide, however, does create some problems. At times, the weight of the equipment can be substantial, and the drawer slide must be able to support substantial loads. This is particularly so when the drawer slide is extended, with the weight substantially distant from the rack. Moreover, failure of the drawer slide to support the load is generally unacceptable. This is due, for example, to the gross disparity between the value of the rack-mounted equipment and the drawer slide. This is also important, for example, for various safety reasons.

BRIEF SUMMARY OF THE INVENTION

The present invention provides a thin telescopic drawer slide.

These and other aspects of the present invention will be more readily understood with reference to the following figures and the accompanying detailed description.

DETAILED DESCRIPTION

FIG. 1illustrates a telescopic drawer slide in accordance with the aspects of the present invention. The drawer slide includes an outer member11. The outer member has a substantially elongate web13, an upper bearing raceway15, and a lower bearing raceway17along upper and lower margins of the elongate web. The terms “upper”, “lower”, and other directional terms are used for convenience of description, in accordance with the usual mounting of the slide to a cabinet or the like.

Nestled within the outer slide member is an intermediate slide member19. The intermediate slide member has a longitudinal elongate web21. The intermediate slide member has an upper outer bearing raceway23, an upper inner bearing raceway24, a lower outer bearing raceway25, and a lower inner bearing raceway26, also along the upper and lower longitudinal margins of the elongate web. Nestled within the bearing raceways of the intermediate slide member is an inner slide member27. The inner slide member has an elongate web29also with upper and lower bearing raceways29,31, respectively, along the margins of the elongate web. The slide members are longitudinally extendable with respect to one another.

The slide ofFIG. 1also includes latching features16. These features are discussed in more detail, for example, in U.S. Provisional Application No. 60/249,137, entitled Friction Slide, filed Nov. 16, 2000, the disclosure of which is incorporated by reference.

FIG. 2illustrates a cross-section of the drawer slide of FIG.1. The drawer slide includes an outer slide member41, an intermediate slide member43, and an inner slide member45. Each of the slide members has a respective vertical web61,63,65with bearing raceways formed in the upper and lower margins of the vertical web. The intermediate slide member is largely nestled within bearing raceways51,52of the outer slide member, and the inner slide member is largely nestled within bearing raceways55,56of the intermediate slide member.

As can be seen inFIG. 2, bearings47are disposed between the upper raceways51of the outer slide member and upward facing upper raceways53of the intermediate slide member, and bearings49are also placed between downward facing upper raceways55of the intermediate slide member and upper raceways57of the inner slide member. Similarly, the bearings are disposed between the raceways of the frame of the lower bearing raceways of the outer slide member and the intermediate slide member, as well as the intermediate slide member and the inner slide member. The bearings slidably couple the slide members. Bearings may be disposed directly in the raceways, or may be disposed within a bearing spacer48or retainer58within the raceway, which serve to retain and properly space the bearings. In operation, the bearings also serve to transfer loads from the inner slide member to the intermediate slide member, and then to the outer slide member. A cross-section of the outer slide member is illustrated in FIG.3. The outer slide member has a vertical web71, with an upper bearing raceway73along the upper margin of the vertical web, and a lower bearing raceway75along the lower margin of the vertical web. In one embodiment, joggled offsets77,79connect the vertical web to the bearing raceways. The offsets are in the same general direction in which the bearing raceways extend from the vertical web, and connect the central portion of the vertical web71, to respective end portions78,80. The end portions78,80are substantially parallel to the central portion of the vertical web71. The offsets minimize bowing or warping of the slide member when subjected to vertical, horizontal, and/or torsional loads. In addition, the offsets provide an additional horizontal offset to the bearing raceways, which provides additional space for mounting hardware or other items between the webs of the outer and intermediate slide members. The additional space is useful, for example, in thin embodiments of the invention, and may be varied to accommodate clearance of specific hardware, such as particular size screws, rivets, stand-offs, pem-nuts, bayonets or other hardware known to those skilled in the art. In one such thin embodiment, a drawer slide with an envelope of 0.375 inch wide by 1.62 high was formed.

FIG. 4further illustrates the joggled offset of the outer slide, and also illustrates a gusset81in the bearing raceway. The linear gusset runs substantially along the length of the bearing raceway. As illustrated, the gusset is substantially along a center line of the bearing raceway. The linear gusset serves to constrain movement, particularly lateral movement, of bearings placed in the raceway. In one embodiment the gusset is formed by pressing on the surface of the bearing raceway. This pressing action serves to provide a cold reduced work hardened surface for contacting the ball bearings, and this surface limits the Brunelling effects.

In one embodiment the linear gusset allows for a65degree contact angle for a ball bearing placed in the raceway. In addition, the radius of the linear gusset provides clearance to allow for point contact of, in one embodiment, a three millimeter size ball bearing.

In one embodiment, integral stops are formed into the upper and lower bearing raceways. The stops provide contact with and contain the bearings or bearing spacers, while maintaining the material integrity of the outer member channel, and providing maximum shear strength for the formed stops. Such stops may be placed as desired to limit longitudinal movement.

FIG. 5illustrates a cross-section of the intermediate slide member. The intermediate slide member includes a substantially vertical web91with bearing raceways93,95along the upper and lower margins of the vertical web. The vertical web includes a central portion97, inset from the upper portion96and lower portion98by two jogs101,103in the vertical web. The inset central portion allows for increased distance between the vertical web of the intermediate slide member and the vertical web of the outer slide member, as may be seen in FIG.2. In one embodiment, the central portion of the vertical web is offset sufficiently to provide clearance for a #8screw. It will be appreciated that the design of the offset distance may be varied to accommodate specific mounting hardware. The inset also provides increased rigidity of the slide member to minimize torsional twisting and bow along the length of the slide member.

In one embodiment, the ball races are formed by bending a portion of a slide member to form a largely doubled-over section approximately at right angles to the vertical web. The doubled-over section forms, using the upper bearing raceways as an example, an intermediate to outer member bearing raceway105and an intermediate to inner member bearing raceway107. The two raceways are offset vertically. The vertical offset allows the material forming the raceways to provide substantially constant material thickness along the bearing raceways. The constant material thickness allows for maintenance of slide member material integrity and improved load bearing capacity. Connecting the two raceways is an angled transition109providing for increased rigidity of the member along the ball races.

A cross-section of the inner slider member is illustrated in FIG.6. The inner slide member has a vertical web111with upper and lower ball bearing raceways113,115along the upper and lower margins, respectively, of the vertical web. The raceways are offset from the web a sufficient distance to provide clearance for mounting hardware used to mount the inner slide member to a drawer or equipment. The width of the vertical web is also sufficient to allow for lancing, forming tabs, and the like for use in mounting.

Returning to the slide ofFIG. 1, it may be seen that mounting brackets are coupled to the slide. More specifically, inFIG. 1a front mounting bracket151is coupled approximate a front edge of the outer slide member, and a rear mounting bracket153is coupled approximate a rear edge of the slide member. As illustrated inFIG. 7, the mounting bracket includes a face plate161. The face plate is adapted to be placed with one side163against the outer slide member. Mounting holes165extend through the face plate to allow mounting screws, hardware and the like to secure the face plate, and thereby the mounting bracket, to the outer slide member.

As illustrated inFIG. 7, the mounting holes are arranged in triangular patterns approximate the forward and rearward edges of the face plate. The placement of the holes in such a pattern allows the mounting bracket to be more easily used with slides of varying profiles, particularly varying heights. In one embodiment, the holes are extruded, with an extrusion167extending outwards from face plate away from the side of the face plate mounted to the outer slide member. The extrusions, in one embodiment, are threaded, thereby allowing for increased ease of use, and perhaps more importantly decreased hardware requirements, for mounting the face plate to the outer slide member.

The mounting bracket also include wrapping flanges171,173(seen also inFIG. 1) extending along the top and bottom edges of the face plate. The wrapping flanges extend in the direction of the slide. The wrapping flanges are adapted to hug or receive the outer slide member, as may be seen in FIG.1. The wrapping flanges thereby provide increased support to the slide member to which the mounting bracket is mated, in this example the outer slide member.

Returning toFIG. 7, the mounting bracket also includes a front flange181. The front flange extends from what for convenience will be termed the front of the face plate. As will be evident, if not so already, the mounting bracket may be mounted to the slide with either the front of the face plate in the direction of the front of the slide or the rear of the slide. The front flange extends in the direction away from the slide, when the mounting bracket is mounted to the slide.

Three holes183are placed in the front flange. The holes are placed in a line, and are suitable for receiving bolts, pins, and other hardware for attaching the mounting brackets to face frames, vertical beams, racks, and similar structures. As may be seen inFIG. 1, the front flange extends away from the slide, and is largely perpendicular to both the direction of extension of the slide and a plane formed by the vertical webs.

The holes in the front flange, in one embodiment, are embossed, protruding towards the front surface of the front flange (with “front” as considered with respect to the discussion of the front flange). The holes therefore allow for more easier seating of, for example, pins placed from the rear of the front flange through to the front surface of the front flange. Moreover, for racks190with square holes191, or sufficiently large round holes193, as may be seen inFIG. 8, the extending protrusions on the front of the front flange allow more readily for seating of the flange in position on the rack during installation.

In one embodiment disposable pins201are also provided to increase ease of installation. As may be seen inFIGS. 8 and 9, the pins are substantially cylindrical with a bulge203about the middle of the pin. The bulge is sized with respect to the holes in the front flange to provide a tight fit, allowing for the pins to be snapped into the holes. The diameter of the forward edge of the pin is sized relative to the holes, or cutouts, in the racks such that the pins may be placed in the cutouts, thereby supporting the mounting bracket, and slide, during installation. After installation is complete and mounting hardware is positioned and secure, the pins may be removed and disposed.

In one embodiment, the pins include a slot205about the middle of the pin. The slot creates a weakened area in the pin about the front flange. This weakened area, when additional force is provided to lever the pin about the front flange, is designed in one embodiment to break and free the pin from the flange when no longer needed. In another embodiment, force is applied to the front of the pin, releasing the pin from engagement with the front flange when the pin is no longer needed.

The present invention therefore provides a thin drawer slide, and accompanying useful related items. Although the invention has been described with respect to certain embodiments, it should be realized that the invention may be practiced other than as specifically described. Accordingly, the invention should be viewed as the claims supported by this specification and their equivalents.