Reference to Related Applications

[0001] This application claims the priority benefit of the filing date of US Provisional Appl. Nos. 61/507,872, filed My 14, 2011, and 61/507,889, filed My 14, 2011. The entire disclosures of US Provisional Appl. Nos. 61/507,872 and 61/507,889 are incorporated herein by reference.

Field of the Disclosure

[0002] This disclosure relates generally to drawer assemblies, and, more particularly, to a carriage for a drawer slide assembly.

Background of the Disclosure

[0003] Many furniture manufacturers use metal drawer slide assemblies having an elongate stationary lower metal drawer guide. The metal drawer guide is secured to an inside structure of a furniture article, and an elongate upper metal drawer slide is secured to the bottom of a drawer at front and rear ends of the drawer, for example. See, e.g., U.S. Pat. No. 6,116,706. Plastic drawer glides are then often mounted to a rear wall of a drawer to facilitate movement of the drawer along the lower metal drawer guide. In most conventional drawer slide assemblies, the lower metal drawer guide consists of a generally U-shaped (or T-shaped) metal rail in cross- section, having flanges projecting horizontally outwardly from the upper ends thereof. The upper metal drawer slide is generally C-shaped in cross-section and has an integral, upwardly- extending metal tab member at the rear end that is secured to the wall of the drawer. The plastic drawer glides prevent complete metal-to-metal contact between the drawer guide and the drawer slide and assist with the movement of the drawer along the drawer guide. [0004] It is desired to reduce friction between relatively-movable components of a drawer slide assembly so as to reduce the sound generated by the plastic drawer glides during use. It is further desirable to provide a drawer slide system that transmits the load of the drawer such that the center of gravity remains inside the drawer.

Summary of the Disclosure

[0005] A carriage for a drawer slide assembly is disclosed. The carriage includes a front end and a rear end disposed opposite the front end, a pair of side walls extending from the front end to the rear end, and a pair of flanges extending from the pair of side walls from the front end to the rear end. The carriage further includes a base connected to the pair of side walls, the base having a first side disposed adjacent to one of the flanges of the pair of flanges and a second side disposed adjacent to the other flange of the pairs of flanges. The carriage further includes a plurality of apertures disposed on each flange of the pair of flanges at both the front and rear ends and at the first and second sides of the base at both the front and rear ends, and a cylindrical bearing is disposed in each of the plurality of apertures. Laterally-extending slots are disposed in each flange of the pair of flanges at both the front and rear ends, and a spacer disc is disposed within each slot, such that only the bearings and the spacer discs contact surrounding surfaces during use of the carriage.

[0006] A drawer slide assembly is also disclosed. The drawer slide assembly includes a carriage having a front end and a rear end disposed opposite the front end, a pair of side walls extending from the front end to the rear end, and a pair of flanges extending from the pair of side walls from the front end to the rear end. The carriage further includes a base connected to the pair of side walls, the base having a first side disposed adjacent to one of the flanges of the pair of flanges and a second side disposed adjacent to the other flange of the pair of flanges. A plurality of apertures is disposed on each flange at both the front and rear ends and at the first and second sides of the base at the front and rear ends of the carriage, and a cylindrical bearing is disposed in each of the plurality of apertures.

[0007] In addition to the carriage, the drawer slide assembly further includes a drawer guide having a front end and a rear end and a pair of outwardly extending flanges extending from the front end to the rear end. The drawer guide is disposed within the carriage such that the flanges of the drawer guide contact the cylindrical bearings within each of the plurality of apertures disposed on the flanges and at the first and second sides of the base of the carriage at both the first and second ends of the carriage.

[0008] The drawer slide assembly further includes a drawer slide having a front end and a rear end, a base, a pair of side walls extending from the base from the front end to the rear end, and a pair of outwardly projecting flanges extending from the side walls from the front end to the rear end. The carriage having the drawer guide disposed therein is inserted into the drawer slide such that the cylindrical bearings of each of the plurality of apertures disposed on the carriage contact the flanges of the drawer slide at one side and the base at an opposite side, and each spacer disc contacts the side walls of the drawer slide.

[0009] The cylindrical bearings and the spacer discs are preferably made of a lubricous material such as an ultra-high molecular weight material, such as UHMW polypropylene or UHMW polyethylene, but alternately may be nylon, polyoxymethylene (POM) or the like. The cylindrical bearings and spacer discs serve to isolate surfaces of the carriage from surrounding surfaces of other components of the drawer slide assembly.

[0010] In another embodiment, a carriage for a drawer slide assembly comprises a front end and a rear end disposed opposite the front end, a pair of side walls extending from the front end to the rear end, a pair of flanges extending from the pair of side walls from the front end to the rear end, and a base connected to the pair of side walls and having a first side disposed adjacent to one of the flanges of the pair of flanges and a second side disposed adjacent to the other flange of the pair of flanges. The carriage further includes a plurality of apertures disposed in each flange of the pair of flanges at both the front and rear ends and at the first and second sides of the base at both the front and rear ends. A cylindrical bearing is disposed in each aperture of the plurality of apertures, wherein each cylindrical bearing is lubricious, and a rib is disposed on each side wall at both the front and rear ends, wherein only the bearings and the ribs contact a surface during use of the carriage.

[0011] The plurality of apertures disposed in each flange of the pair of flanges may further include at least two apertures in each of the front and rear ends of each of the flanges. In a similar manner, the plurality of apertures disposed at the first and second sides of the base at both the front and rear ends may include at least three apertures. In addition, each cylindrical bearing disposed in each plurality of apertures in the pair of flanges may be exposed on a top portion and a bottom portion of each flange, and each cylindrical bearing disposed in each plurality of apertures in the first and second sides of the base may be exposed on a top portion of the base and a bottom portion of the carriage.

[0012] Further, the cylindrical bearings may roll freely within each aperture. In addition, each bearing may be made of an ultra-high molecular weight material, such as UHMW polypropylene or UHMW polyethylene, or alternately, polyoxymethylene.

[0013] Still further, the carriage may further comprise a recess disposed between the pair of side walls and adjacent to the pair of flanges, and, in combination with a drawer guide, the drawer guide received within the recess and only the cylindrical bearings and ribs of the carriage may contact the drawer guide.

[0014] In addition, each rib extending from each side wall at the front and rear ends of the carriage may be generally rectangular in shape. Each rib may also be made of a plastic material.

[0015] In another example of the present disclosure, a drawer slide assembly comprises a carriage having a front end and a rear end disposed opposite the front end, a pair of side walls extending from the front end to the rear end, a pair of flanges extending from the pair of side walls from the front end to the rear end, and a base connected to the pair of side walls and having a first side disposed adjacent to one of the flanges of the pair of flanges and a second side disposed adjacent to the other flange of the pair of flanges. A plurality of apertures disposed on each flange at both the front and rear ends and at the first and second sides of the base at the front and rear ends, and a cylindrical bearing disposed in each aperture of each plurality of apertures, wherein each cylindrical bearing is lubricious. A pair of ribs, one such rib extending from each side wall at both the first and second ends of the carriage, is also included. The drawer slide assembly further includes a drawer guide having a pair of side walls, a front end, a rear end and a pair of outwardly extending flanges extending from the front end to the rear end, wherein the drawer guide is disposed within the carriage such that the flanges of the drawer guide contact the cylindrical bearings within each of the plurality of apertures disposed on each flange of the carriage and at the first and second sides of the base of the carriage at both the front and rear ends of the carriage. In addition, the drawer slide assembly includes a drawer slide having a front end and a rear end, a base, a pair of side walls extending from the base from the front end to the rear end, and a pair of inwardly projection flanges extending from the side walls from the front end to the rear end, wherein the carriage having the drawer guide inserted therein is disposed within the drawer slide such that the cylindrical bearings of each of the plurality of apertures disposed on the carriage contact the flanges of the drawer slide at one side and the base at an opposite side and each rib extending from the carriage contacts the pair of side walls of the drawer slide, thereby protecting the carriage from contact with either of the side walls of the drawer slide.

[0016] In yet a further example, a carriage may have both lateral ribs and lateral rotating spacer elements.

[0017] In yet an additional example, a carriage of the present disclosure may be selectively foldable, such as along integral axially-extending living hinges that run the length of the carriage, between an unassembled, unfolded condition, and a folded, assembled condition.

Brief Description of the Several Views of the Drawings

[0018] FIG. 1 is a perspective view a drawer guide, a carriage and a drawer slide of a drawer slide assembly of the present disclosure;

[0019] FIG. 2 is a perspective view of the carriage of the drawer slide assembly of FIG. 1;

[0020] FIG. 2a is perspective view of a cylindrical bearing of the carriage of the drawer slide assembly of FIG. 1;

[0021] FIG. 2b is a front view of the cylindrical bearing of the carriage of the drawer slide assembly of FIG. 1;

[0022] FIG. 2c is a side view of the cylindrical bearing of the carriage of the drawer slide assembly of FIG. 1; [0023] FIG. 3 is a side perspective view of a portion of the carriage of the drawer slide assembly of FIG. 1;

[0024] FIG. 4 is a front perspective view of a portion of the carriage of the drawer slide assembly of FIG. 1 having the drawer guide disposed therein, illustrating the components in a partially-open-drawer condition;

[0025] FIG. 5 is another front perspective view of a portion of the carriage of the drawer slide assembly of FIG. 1 having the drawer guide disposed therein, illustrating the components in a closed-drawer condition;

[0026] FIG. 6 is a side perspective view of the carriage having the drawer guide disposed therein, illustrating the components in a partially-open-drawer condition;

[0027] FIG. 7 is bottom perspective view of the carriage having the drawer guide disposed therein;

[0028] FIG. 8 is a side perspective view of a portion of the drawer guide disposed within the carriage;

[0029] FIG. 9 is a side, perspective view of a portion of the drawer slide assembly, illustrating the drawer guide disposed within the carriage and the carriage disposed within a portion of the drawer slide;

[0030] FIG. 10 is top view of a portion of the drawer slide assembly, further illustrating the drawer guide disposed within the carriage and the carriage disposed within the drawer slide;

[0031] FIG. 11 is a perspective view of a drawer guide, a carriage, and a drawer slide of a drawer slide assembly of the present disclosure; [0032] FIG. 12 is a top, perspective view of the carriage of the drawer slide assembly of FIG.

11;

[0033] FIG. 13 is a side, perspective view of the carriage of the drawer slide assembly of FIG.

11;

[0034] FIG. 14 is a bottom view of the carriage of the drawer slide assembly of FIG. 11;

[0035] FIG. 15 is a side view of the carriage of the drawer slide assembly of FIG. 11;

[0036] FIG. 16 is side, perspective view of a portion of the drawer slide assembly, illustrating the drawer guide disposed within the carriage and the carriage disposed within the drawer slide;

[0037] FIG. 17 is a perspective view of a further alternate embodiment of a carriage for a drawer slide assembly, illustrated on a drawer guide;

[0038] FIG. 18 is a perspective view of yet an additional embodiment of a carriage for a drawer slide assembly, with the carriage illustrated in an assembled condition on a drawer guide;

[0039] FIG. 19 is a top perspective view of the carriage of FIG. 18, illustrated in an unassembled, unfolded condition;

[0040] FIG. 20 is a front plan view of a carriage of FIGS. 18 and 19 just before folding into an assembled condition; and

[0041] FIG. 21 is a front end view of the carriage of FIGS. 18-20 folded into an assembled condition on a drawer guide, and installed within a drawer slide or case runner.

Detailed Description of the Disclosure

[0042] Referring now to Fig. 1, a drawer slide assembly 10 is illustrated. The drawer slide assembly 10 includes an elongate, metal drawer guide 12 that is U-shaped, a C-shaped drawer slide 14, and a carriage 16. As described in more detail below, the drawer guide 12 fits within the carriage 16, and the carriage 16 with the drawer guide 12 inserted therein together fit within the drawer slide 16 to form the drawer slide assembly 10.

[0043] The drawer guide 12 includes a rail having a U-shaped cross-section, with horizontal, outwardly projecting flanges 18, 20. An aperture 22 for receiving a screw or other attachment mechanism is disposed on both a front end 19 and a rear end 21 of the drawer guide 12. The apertures 22 receive an attachment mechanism, allowing both ends of the drawer guide 12 to be secured to a portion of a furniture unit. In one example, the front end 19 of the drawer guide 12 may be secured to a front drawer cross support by a screw positioned through the aperture 22 at the front end 19 of the drawer guide 12. In a similar manner, the rear end 21 of the drawer guide 12 may also be secured to a rear drawer cross support by another screw positioned through the aperture 22 (not shown) at the rear end of the drawer guide 12.

[0044] The drawer slide 14 is an elongate metal rail that is C-shaped in cross-section and includes vertical side walls 24, 26 and inwardly projecting flanges 28, 30. An end stop 36 is disposed at a front end 32 of the drawer slide 14. The end stop 36 is made of a rolled metal material that has enough resistance to be pushed down initially upon receiving the drawer guide 12 and carriage 16 combination and enough resilience to spring back into its original position after the drawer guide 12 and carriage 16 combination clear the end stop 36.

[0045] Referring now to Fig. 2, the carriage 16 includes a front end 40 and a rear end 42, vertical side walls 44, 46 and inwardly projecting flanges extending the length of the carriage 16 from the front end 40 to the rear end 42. The flanges 48, 50 include top portions 48a, 50a and bottom portions 48b, 50b. The carriage 16 further includes a base 51 having a first side 53 disposed adjacent to flange 48 and a second side 54 disposed adjacent to flange 50. The carriage 16 may, by way of example, be made of an ABS material or any other material that allows bearings 56, which are described in more detail below, to have lubricity.

[0046] A plurality of apertures 52 is disposed on both the front and rear ends 40, 42 of both flanges 48, 50 of the carriage 16. A plurality of apertures 52 is also disposed on each of the first and second sides 53, 54 of the base 51 (Fig. 3) at both the front end 40 and rear end 42 (not shown) of the carriage 16. While the plurality of apertures 52 may vary, in one example, each plurality of apertures 52 includes three apertures 55.

[0047] Cylindrical, bearings 56 are disposed in each aperture 55 of each of the plurality of apertures 52 disposed in the flanges 48, 50 and the first and second sides 53, 54 of the base 51. The bearings 56 are disposed within the apertures 55 of the flanges 48, 50 such that a portion of each bearing 56 is exposed on the top portions 48a, 50a and the bottom portions 48b, 50b (Fig. 3) of each flange 48, 50. In a similar manner, the bearings 56 are disposed within the apertures 56 of the first and second sides 53, 54 of the base 51 of the carriage 16 such that a portion of each bearing 56 is exposed on a top portion the base 51 within the recess 62 and on a bottom 58 portion (Fig. 7) of the carriage 16. The bearings 56 roll freely within each aperture 55. The bearings 56 are also lubricious, thereby reducing friction and sound created by the movement between the carriage 16, the drawer guide 12, and the drawer slide 14 during use of a drawer.

[0048] The bearings 56 may, by way of example, be made of ultra-high molecular weight (UHMW) materials (such as UHMW polyethylene (PE) or UHMW polypropylene (PP)), nylon or polyoxymethylene (POM), also known as acetal, polyacetal, and polyformaldehyde, which is an engineering thermoplastic used in precision parts that require high stiffness, low friction and excellent dimensional stability. Some leading POM producers include Ticona Hostaform, DuPont Derlin, Polyplastic Duracon, and Korea Engineering Plastics. See, e.g., http://en.wikipedia.org/wild/Polyoxyrnethylene (as reviewed on March 21, 2011). POM is generally characterized by its high strength, hardness, and rigidity to -40 degrees Celsius. While POM is intrinsically opaque white due to its high crystalline composition, it is available in all colors. POM has a density of p = 1.410-1.420 g/cm 3. POM is sensitive to oxidation, and an anti-oxidant is normally added to molding grades of the material. Advantages of POM include high abrasion resistance, low coefficient of friction, high heat resistance, good electrical and dielectric properties, and low water absorption. POM's high abrasion resistance and low coefficient of friction advantages are particularly relevant and useful for this drawer slide assembly application.

[0049] As illustrated in Figs. 2A-2C, each bearing is cylindrically shaped. POM is often supplied in granulated form and can be formed into this desired shape by applying heat and pressure. The two most common forming methods employed are injection molding and extrusion. Rotational and blow molding are also possible. POM is commonly extruded as continuous lengths of round or rectangular section, which can be cut to length and sold as bar or sheet stock for machining. See, e.g., http://en.wikipedia.org/wiki/Polyoxymethylene (as reviewed on March 21, 2011).

[0050] The bearings 56 may alternatively, and also by way of example, be made of nylon 612 with additive for lubricity, or polyphenylene sulfide or acetal-PTFE, where lubricants are added/compounded with plastic. In general, plastics with good lubricity tend to have low coefficients of friction with other materials and do not have a tendency to gall, i.e., wear away by friction, but most preferably are made of a UHMW material.

[0051] Referring now to Fig. 3, the carriage 16 further includes a recess 62 disposed between the side walls 44, 46 and below the flanges 48, 50. The plurality of apertures 52 disposed on the first side 53 of the base 51 of the carriage is also illustrated. A portion of the plurality of apertures 52 disposed on the second side 54 of the base 51 opposite the first side 53 is partially illustrated. The drawer guide 12 fits within the recess 62 of the carriage 16, such that the flanges 18, 20 of the drawer guide 12 fit between the bearings 56 disposed within the plurality of apertures 52 on the flanges 48, 50 and the first and second sides 53, 54 of the carriage base 51. In other words, when the drawer guide 12 is inserted into the recess 62 of the carriage, bearings 56 from the plurality of apertures 52 disposed within the flanges 48, 50 of the carriage 16 and bearings 56 from the plurality of apertures 52 disposed within the first and second sides 53, 54 of the base 51 of the carriage 16 are on either side of the flanges 18, 20 of the drawer guide 12. See also Figs. 4, 5 and 6.

[0052] Referring now to Figs. 4, 5 and 6, the drawer guide 12 of the drawer slide assembly 10 is sitting within the carriage 16. The drawer guide 12 is moveable between a range of positions within the carriage 16 in view of the lubricious bearings 56 disposed within the plurality of apertures 52 of the carriage 16. In other words, the bearings 56 of the plurality of apertures 52 are on either side of the flanges 18, 20 of the drawer guide 12 upon having the drawer guide 12 inserted into the carriage 16, allowing the drawer guide 12 to move smoothly, easily, and with hardly any noise through a range of positions within the carriage 16. Fig. 5 illustrates the drawer guide 12 partially disposed within the carriage 16, such that a portion of the drawer guide 12 extends outside of the front end 42 of the carriage 16. Fig. 6 illustrates the drawer guide 12, such that the front end 19 of the drawer guide 12 is flush with the front end 42 of the carriage 16 and no portion of the drawer guide 12 extends outside of the front end 42 of the carriage 16. Fig. 7 illustrates the drawer guide 12 disposed within the carriage 16, such that the front portion 21 of the drawer guide 12 is moved to a position completely within the carriage 16 and beyond the plurality of apertures 56 disposed in both the flanges 48, 50 and the first and second sides 53, 54 of the base 51 of the carriage 16. While not illustrated in Fig. 7, in as much as the drawer guide 12 is larger than the carriage 16, one of skill in the art can appreciate that the rear end 21 of the drawer guide 12 extends outside of the rear end 42 of the carriage 16 in this position.

[0053] Fig. 6 further illustrates lateral slots 68a, 68b disposed on the flanges 48, 50 at the front end 40 of the carriage 16. While not illustrated in Fig. 6, slots 68c (Fig. 8), 68d are also disposed on the flanges 48, 50 at the rear end 42 of the carriage 16. Discs or spacers 70a, 70b are disposed within the slots 68a, 68b at the front end 40 of the carriage 16, and discs or spacers 70c, 70d are disposed within the slots 68c, 68d at the rear end 42 of the carriage 16. The diameter of each of the spacers 70a, 70b, 70c, and 70d is greater than the width of each of the slots 68a-68d, such that the spacers 70a-70d contact the interior of the vertical side walls 24, 26 of the C-shaped drawer slide 14, for example, and essentially float the carriage 16 so that its always spaced from any walls of the C-shaped drawer slide 14 (as a bumper or fender protects a boat hull from a dock). In other words, only the bearings 56 and the spacers 70a-70d bear against surrounding surfaces, i.e., the bearings 56 contact the drawer guide 12 and the spacers 70a-70d contact the sidewalls of 24, 26 of the C-shaped drawer slide 14. The spacers 70a, 70b, 7c, and 7d further contact sidewalls 13, 15 of the drawer guide 12, thereby providing additional cushioning between the carriage 16 and the drawer guide 12. Other than the bearings 56 and the discs 70a- 70d, neither the flanges 48, 50 nor any other portion of the carriage 16 bear against or contact any surrounding surface of the drawer slide assembly 10.

[0054] Fig. 7 illustrates a bottom perspective view of the drawer guide 12 disposed within the carriage 16. The base 51 of the carriage 16 includes a bottom portion 58, and the plurality of apertures 52 disposed on the first and second sides 53, 54 of the base 51 are also illustrated in this view. Each aperture 55 of the plurality of apertures 52 disposed on the first and second sides 53, 54 of the base 51 extend from a top portion of the base 51 to the bottom portion 58 of the base, allowing the bearings 56 to be exposed on both the top and bottom portions of the first and second sides 53, 54 of the base 51 of the carriage 16. Fig. 7 further illustrates the drawer guide 12 disposed within the carriage 16 having a portion of the drawer guide 12 extending outside of the front end 40 of the carriage 16.

[0055] Fig. 8 illustrates a side perspective view of the drawer guide 12 disposed within the carriage 16. In this view, the front end 19 of the drawer guide 12 extends prominently of the front end 40 of the carriage 16, and the rear end 21 of the drawer guide 12 also extends beyond the rear end 42 of the carriage 16. The length of the carriage 16 and the distribution of the bearings 56 along the longitudinal axis of the carriage 56 (as opposed to concentrating bearings at one or both ends of a drawer guide or drawer slide) help keep the center of gravity of the drawer slide assembly 10 inside a drawer or furniture unit, preventing unwanted tipping of the drawer or furniture unit in which the drawer slide assembly 10 is being used. In addition, the spacing of plurality of apertures 52 at the front end of the flanges 48, 50 of the carriage 16 from the plurality of apertures 52 at the rear end of the flanges 48, 50 also helps maintain the center of gravity of drawer slide assembly 10 inside of the drawer or furniture unit, further preventing unwanted tipping of the drawer or furniture unit during use of the drawer slide assembly 10.

[0056] Figs. 9 and 10 illustrate the drawer guide 12 disposed within the carriage 16, and the carriage 16 and drawer guide 12 disposed within the drawer slide 14. More specifically, the drawer slide 14 receives the carriage 16 having the drawer guide 12 disposed therein, such that the bearings 56 disposed within each of the recesses 55 of each of the plurality of apertures 52 disposed on the carriage 16 contact the flanges 28, 30 of the drawer slide 14 at one side and the base 29 (Fig. 1) of the drawer slide 14 at an opposite side. In addition, the discs 70a-70d disposed within the carriage 16 contact the side walls 24, 26 (Fig. 1) of the drawer slide 14, e.g., discs 70a and 70c contact the side wall 26 and discs 70b and 70d contact the side wall 24 of the drawer slide 14. As such, the drawer slide 14 only contacts the bearings 56 and the spacer discs 70a-70d when the carriage 16 having the drawer guide 12 inserted therein is inserted into the drawer slide 14. The drawer slide 14 does not contact the drawer guide 12 when the carriage 16 is inserted into the drawer slide 14; only the lubricious bearings 56 of the carriage 16 and the lubricious discs 70a-70d contact the drawer guide 12 and the drawer slide 14. This allows a drawer or furniture unit attached to the drawer slide assembly 10 to be opened and closed in a very smooth, silent manner with minimal friction.

[0057] Referring now to FIG. 11, a drawer slide assembly 10 is illustrated. The drawer slide assembly 10 includes an elongate, metal drawer guide 12 that is U-shaped, a C-shaped drawer slide 14, and a carriage 16. As described in more detail below, the drawer guide 12 fits within the carriage 16, and the carriage 16 with the drawer guide 12 inserted therein together fit within the drawer slide 16 to form the drawer slide assembly 10.

[0058] The drawer guide 12 includes a rail having a U-shaped cross-section, with horizontal, outwardly projecting flanges 18, 20. An aperture 22 for receiving a screw or other attachment mechanism is disposed on both a front end 19 and a rear end 21 (not shown) of the drawer guide 12. The apertures 22 receive an attachment mechanism, allowing both ends of the drawer guide 12 to be secured to a portion of a furniture unit. In one example, the front end 19 of the drawer guide 12 may be secured to a front drawer cross support by a screw positioned through the aperture 22 at the front end 19 of the drawer guide 12. In a similar manner, the rear end 21 of the drawer guide 12 may also be secured to a rear drawer cross support by another screw positioned through the aperture 22 (not shown) at the rear end of the drawer guide 12.

[0059] The drawer slide 14 is an elongate metal rail that is C-shaped in cross-section and includes vertical side walls 24, 26 and inwardly projecting flanges 28, 30. An end stop 36 is disposed at a front end 32 of the drawer slide 14. The end stop 36 is made of a rolled metal material that has enough resistance to be pushed down initially upon receiving the drawer guide 12 and carriage 16 combination and enough resilience to spring back into its original position after the drawer guide 12 and carriage 16 combination clear the end stop 36.

[0060] Referring now to FIG. 12, the carriage 16 includes a front end 40 and a rear end 42, vertical side walls 44, 46 and flanges 48, 50 extending the length of the carriage 16 from the front end 40 to the rear end 42. The flanges 48, 50 include top portions 48a, 50a and bottom portions 48b, 50b (FIG. 13). The carriage 16 further includes a base 51 disposed between the flanges 48, 50 and extending the length of the carriage 16 from the front end 40 to the rear end 42. The base 51 further includes a first aperture 61 disposed at the front end 40 of the carriage 16, a second aperture 63 disposed at the rear end 42 of the carriage 16, and a third aperture 65 disposed between the first and second apertures 61, 63. The first, second and third apertures 61, 63, 65 are generally rectangular in shape, but may take the form of a variety of other shapes, including, but not limited to, circular, semi-circular, square, oval, hexagonal, triangular, and octagonal shapes, for example. The carriage 16 may, by way of example, be made of an ABS material or any other material that allows bearings 56a, 56b, which are described in more detail below, to have lubricity.

[0061] As further illustrated in FIG. 12, an elongate tab 67 is disposed within the third aperture 65 of the base 51. More specifically, the elongate tab 67 may be made of a rolled metal or plastic material that has enough resistance to be pushed down when the drawer guide 12 is inserted into the carriage 16 and enough resilience to spring back into its original position when the carriage 16 is removed from the drawer guide 12, for example.

[0062] The base 51 of the carriage 16 further includes a first side 53 disposed adjacent to the flange 48 and a second side 54 disposed adjacent to the flange 50. A plurality of apertures 52a is disposed on both the front and rear ends 40, 42 of both flanges 48, 50 of the carriage 16. A plurality of apertures 52b (FIG. 4) is also disposed on each of the first and second sides 53, 54 of the base 51 at both the front end 40 and rear end 42 (not shown) of the carriage 16. While the plurality of apertures 52a, 52b may vary, in one example, each plurality of apertures 52a includes two apertures 55a and each of the plurality of apertures 52b includes three apertures 55b (FIG. 4).

[0063] Cylindrical bearings 56a, 56b are disposed in apertures 55a, 55b, respectively, in each of the plurality of apertures 52a disposed in the flanges 48, 50 and each of the plurality of apertures 52b disposed in the first and second sides 53, 54 of the base 51. The bearings 56a are disposed within the apertures 55a of the flanges 48, 50 such that a portion of each bearing 56a is exposed on the top portions 48a, 50a and the bottom portions 48b, 50b (FIG. 3) of each flange 48, 50. In a similar manner, the bearings 56b are disposed within the apertures 55b of the first and second sides 53, 54 of the base 51 of the carriage 16 such that a portion of each bearing 56b is exposed on a top portion the base 51 and on a bottom 58 portion (FIG. 3) of the carriage 16. The bearings 56a, 56b roll freely within each aperture 55a, 55b. The bearings 56a, 56b are also lubricious, thereby reducing friction and sound created by the movement between the carriage 16, the drawer guide 12, and the drawer slide 14 during use of a drawer. [0064] The bearings 56a, 56b may, by way of example, be made of UHMW materials (such as UHMW PE or UHMW PP), nylon or polyoxymethylene (POM), also known as acetal, polyacetal, and polyformaldehyde, which is an engineering thermoplastic used in precision parts that require high stiffness, low friction and excellent dimensional stability. Some leading POM producers include Ticona Hostaform, DuPont Derlin, Polyplastic Duracon, and Korea

Engineering Plastics. See, e.g., http://en.wikipedia.org/wiki/Polyoxymethylene (as reviewed on March 21, 2011). POM is generally characterized by its high strength, hardness, and rigidity to - 40 degrees Celsius. While POM is intrinsically opaque white due to its high crystalline composition, it is available in all colors. POM has a density of p = 1.410-1.420 g/cm 3. POM is sensitive to oxidation, and an anti-oxidant is normally added to molding grades of the material. Advantages of POM include high abrasion resistance, low coefficient of friction, high heat resistance, good electrical and dielectric properties, and low water absorption. POM's high abrasion resistance and low coefficient of friction advantages are particularly relevant and useful for this drawer slide assembly application.

[0065] Each bearing is 56a, 56b is cylindrically shaped. POM is often supplied in granulated form and can be formed into this desired shape by applying heat and pressure. The two most common forming methods employed are injection molding and extrusion. Rotational and blow molding are also possible. POM is commonly extruded as continuous lengths of round or rectangular section, which can be cut to length and sold as bar or sheet stock for machining. See, e.g., http://en.wikipedia.org/wiki/Polyoxymethylene (as reviewed on March 21, 2011).

[0066] The bearings 56a, 56b may alternatively, and also by way of example, be made of nylon 612 with additive for lubricity, or polyphenylene sulfide or acetal-PTFE, where lubricants are added/compounded with plastic. In general, plastics with good lubricity tend to have low coefficients of friction with other materials and do not have a tendency to gall, i.e., wear away by friction, but most preferably are made of a UHMW material.

[0067] Referring now to FIG. 13, the carriage 16 further includes a recess 62 disposed between the side walls 44, 46 and below the flanges 48, 50. The plurality of apertures 52b disposed on the first side 53 of the base 51 of the carriage is also illustrated. A portion of the plurality of apertures 52b disposed on the second side 54 of the base 51 opposite the first side 53 is partially illustrated. The drawer guide 12 fits within the recess 62 of the carriage 16, such that the flanges 18, 20 of the drawer guide 12 fit between the bearings 56a, 56b disposed within the plurality of apertures 52a, 52b on the flanges 48, 50 and the first and second sides 53, 54 of the carriage base 51, respectively. In other words, when the drawer guide 12 is inserted into the recess 62 of the carriage, bearings 56a from the plurality of apertures 52a disposed within the flanges 48, 50 of the carriage 16 and bearings 56b from the plurality of apertures 52b disposed within the first and second sides 53, 54 of the base 51 of the carriage 16 are on either side of the flanges 18, 20 of the drawer guide 12.

[0068] The drawer guide 12 is moveable between a range of positions within the carriage 16 in view of the lubricious bearings 56a, 56b disposed within the plurality of apertures 52a, 52b of the carriage 16. In other words, the bearings 56a, 56b of the plurality of apertures 52a, 52b are on either side of the flanges 18, 20 of the drawer guide 12 upon having the drawer guide 12 inserted into the carriage 16, allowing the drawer guide 12 to move smoothly, easily, and with hardly any noise through a range of positions within the carriage 16.

[0069] Referring now to FIG. 14, a bottom view of the carriage 16 is illustrated. The carriage 16 further includes lateral ribs 68 disposed on the side walls 44, 46 at both the front and rear ends 40, 42 of the carriage 16. More specifically, the ribs 68 extend from the side walls 44, 46 of the carriage 16, and, in this example, have an elongate, rectangular shape with rounded edges. In other examples, the ribs 68 may take the form of various other shapes, including, but not limited to, semi-circular and circular shapes. The ribs 68 contact the interior of the vertical side walls 24, 26 of the C-shaped drawer slide 14 (FIG. 11), for example, when the carriage 16 having the drawer guide 12 disposed therein is inserted into the drawer slide 14. The ribs 68 essentially float the carriage 16 so that it is always spaced from any walls of the C-shaped drawer slide 14 (as a bumper or fender protects a boat hull from a dock). In other words, only the bearings 56a, 56b and the ribs 68 bear against surrounding surfaces, i.e., the bearings 56a, 56b contact the drawer guide 12 and the ribs 68 contact the sidewalls of 24, 26 of the C-shaped drawer slide 14. Other than the bearings 56a, 56b and the ribs 68, neither the flanges 48, 50 nor any other portion of the carriage 16 bear against or contact any surrounding surface of the drawer slide assembly 10.

[0070] FIG. 15 illustrates a side view of the carriage 16. Each bearing 56a, 56b extends outside of the flange 48, 50 and the first and second sides 53, 54 of the base, respectively, preventing the flanges 48, 50, for example, of the carriage 16 from bearing against or contacting any surrounding surface of the drawer slide assembly 10. FIG. 15 further illustrates the elongate tab 67 in a raised position.

[0071] Fig. 16 illustrates the drawer guide 12 disposed within the carriage 16, and the carriage 16 and drawer guide 12 disposed within the drawer slide 14. More specifically, the drawer slide 14 receives the carriage 16 having the drawer guide 12 disposed therein, such that the bearings 56a disposed within each of the recesses 55a of each of the plurality of apertures 52a disposed on the carriage 16 contact the flanges 28, 30 of the drawer slide 14 at one side. In a similar manner, the bearings 56b disposed within each of the recesses 55b of each of the plurality of apertures 52b disposed on the carriage contact the base 29 (FIG. 11) of the drawer slide 14 at an opposite side. In addition, the ribs 68 disposed within the carriage 16 contact the side walls 24, 26 (FIG. 11) of the drawer slide 14. As such, the drawer slide 14 only contacts the bearings 56a, 56b and the ribs 68 when the carriage 16 having the drawer guide 12 inserted therein is inserted into the drawer slide 14. The drawer slide 14 does not contact the drawer guide 12 when the carriage 16 is inserted into the drawer slide 14; only the lubricious bearings 56a, 56b of the carriage 16 and the ribs 68 contact the drawer guide 12 and the drawer slide 14. This allows a drawer or furniture unit attached to the drawer slide assembly 10 to be opened and closed in a very smooth, silent manner with minimal friction.

[0072] The length of the carriage 16 and the distribution of the bearings 56a, 56b along the longitudinal axis of the carriage 16 (as opposed to concentrating bearings at one or both ends of a drawer guide or drawer slide) help keep the center of gravity of the drawer slide assembly 10 inside a drawer or furniture unit, preventing unwanted tipping of the drawer or furniture unit in which the drawer slide assembly 10 is being used. In addition, the spacing of plurality of apertures 52a at the front end of the flanges 48, 50 of the carriage 16 from the plurality of apertures 52a at the rear end of the flanges 48, 50 also helps maintain the center of gravity of drawer slide assembly 10 inside of the drawer or furniture unit, further preventing unwanted tipping of the drawer or furniture unit during use of the drawer slide assembly 10.

[0073] Turning now to Fig. 17, a carriage 16 is illustrated on a drawer guide 12. The carriage 16 of this embodiment features a plurality of bearings 56 in a top surface 80 that minimizes friction at least between an interior of the carriage 16 and flanges of the drawer guide 12, side ribs 68 that minimize friction between the exterior of the carriage 16 and interior surfaces of a drawer slide or case runner (not shown in Fig. 17), similar to the side ribs of the carriage illustrated in Fig. 12, as well as lateral spacer discs 70, similar to those of the carriage of the embodiment illustrated in Figs. 2, 4, 5, and 7-9, that are seated in complementary slots and further minimize friction between the interior of the drawer slide or case runner and the carriage 16. The carriage 16 of this embodiment further includes a top rib 82 projecting prominently of the top surface 80 and extending substantially the axial length of the carriage 16, even further minimizing friction between the interior of the drawer slide or case runner and the carriage 16, while helping to maintain smooth linear travel along the drawer guide and along the case runner or drawer slide.

[0074] Turning to Figs. 18-21, a further alternate embodiment of a carriage 16 is illustrated. In this embodiment, the carriage 16 features a plurality of integral living hinges 90 extending the length of the carriage 16. These living hinges 90 permit the carriage 16, which may be made of an injection molded plastic, to be selectively folded from an unfolded, unassembled condition, as illustrated in Fig. 19, to a folded, assembled condition, as illustrated in Fig. 18. In the folded condition, the carriage 16 can be positioned about the flanges of a drawer guide 12.

[0075] The carriage may be provided with bearings 56 and spacer discs 70, as in the other embodiments described above. The bearings 56 and/or the spacer discs 70 may be formed as hollowed-out cylinders of UHMW material and provided with axle-like plastic pins 72 in their cores to facilitate rolling.

[0076] While various embodiments have been described herein, it is understood that the appended claims are not intended to be limited thereto, and may include variations that are still within the literal or equivalent scope of the claims.