US 3203749 A
Description (OCR text may contain errors)
g 31, 1965 E. c. BULLocK ETAL 3,203,749
EXTENDIBLE DRAWER SLIDE 2 SheetsSheec l Filed July 3l, 1963 Aug- 31, 1965 E. c. BULLocK ETAL 3,203,749
EXTENDIBLE DRAWER SLIDE Filed July l, 196s 2 sheets-sheet 2 INVENTORS` 4,645 6'. 50M 06X Wi/AA! E Olii! United States Patent O 3,203,749 EXTENDIBLE DRAWER SLIDE Earle C. Bullock, Grand Rapids, and Adrian R. Olree, Caledonia, Mich., assignors to Steelcase, Inc., Grand Rapids, Mich., a corporation of Michigan Filed July '31, 19'63, Ser. No. 298,895 4 Claims. (Cl. 'S12- 339) This invention relates to extensible drawer supports, and more particularly `to extensible drawer support rail assemblies including a case rail, suspension rail, and a drawer rail, and normally employed to support drawers in cabinets such as tile cabinets.
The extension of drawer support rails separated by antifriction means such as balls, is conventionally purposely limited by placing cooperative stops on the rails to abut the opposite sides of the balls. The stops extend into the ball raceways. When the rail-s are extended to the maximum the balls are each trapped between two of the stop bosses.
When a heavily loaded drawer is extended to the limit, a considerable impact force is momentarily concentrated on the stops to halt Ithe moving drawer. The stops must therefore be extremely sturdy and resistant to shear to withstand this sharp impact force. Failure of the stops, 'allowing over-extension of the drawer support could readily result in a serious accident. As a consequence, the stops are conventionally formed of rigid metal elements, often integrally formed from the rails themselves.
When these metal stops abut the intermediate steel ball as the drawer reaches maximum extension, the audible clunk is very noticeable, and often disturbing throughout the oilice in which the flle cabi-net is located. This factor has heretofore been considered an unpleasant but necessary distraction. This concentrated impact force not only results in undesirable noise, but also, and probably more important, it causes jarring and vibration of the entire cabinet framework tending to weaken it.
It is therefore an object of this invention to provide a drawer suspension support having the stundiness and reliability of a conventional support employing rigid metallic stops, while at the same time achieving `an extremely quiet and cushioned stop operation. The traditional clunk occurring with extension to the limit, and the accompanying jarring of the framework is actually eliminated.
It is another object of this invention to provide a resilient drawer rail stop assembly that employs a resilient rubber or rubber-like element for cushioned stop abutment, but which is not sheared off by the concentrated impact force due to its unique mounting. Rather, the greater the impact force the more the rubber stop element is forced against the wall of the rail for stability.
It is another object of this invention to prov-ide a resilient drawer rail stop employing a metallic mounting clip for securement of a resilient bumper to the wall of the rail, yet not requiring any spot welding or bolting for atrtachment of lthe clip to the r-ail.
It is another object of this invention to provide a rail support assembly employing a cushioned resilient stop assembly, but which, in even case of failure of the resilient stops, will not allow over-extension of the drawer to cause an accident.
Still another object of this invention is to provide a drawer support resilient stop assembly that not only has cushioned stop advantages, but also is simple in yconstruction, relatively inexpensive to manufact-ure and assemble, and rapid and easy to assemble.
These and several Aother objects will become apparent upon studying the following specilication in conjunction with the drawings in which:
FIG. 1 is a side elevational view of the novel drawer support assembly with the rails extended;
FIG. 2 is a side elevational View of the drawer support assembly with the rails in close-d position;
FIG. 3 is a sectional elevational view taken on plane III-IH of the support assembly in FIG. 2;
tFlG. 4 is a perspective enlarged view of the resilient bumper element of the novel stop assembly;
FIG. 5 is a perspective enlarged View of the metallic mount-ing clip for ythe resilient bumper illustrated in FIG. 4, to form a bumper stop;
FIG. 6 is .an enlarged, fragmentary sectional view of a portion of the rail wall and stop assembly taken on plane Ill-III of FIG. 2;
FIG. 7 is a fragmentary enlarged plan View of cooperative stop elements in the abutment on opposite sides of a ball;
FIG. 8 is an end elevational View of the ra-il assembly illustrated in FIG. 2, .taken on plane VEL-VIII;
FIG. 9 is a sectional view of the rail assembly illus- 'tr-ated in FIG. 2 taken on plane IPC-1X.
Referring now specifically to the drawings, the drawer suspension support assembly 10 includes a .drawer rail 12, a suspension rail 14, and a case rail 16.
A pair of these suspension assemblies is used to support a drawer yon the drawer rail, in a cabinet case. The forward end of the case rail 16 is secured to the case frame by intertting rivets with key hole shaped slots or the like. On back end of each case rail, is an L-shaped plate 20 having a rear flange and bottom flange. It attaches the rear of the case rail to the wall of the case. On the back flange of this bracket or plate is a pair of resilient pads 22 and 24 for cushioned abutment of the drawer and suspension rail respectively when the drawer is cl-osed.
Preferably, all three rails are formed of a plurality of identical channel sections. More specifically, referring to FIG. 8, drawer rail 12 is formed of one channel, case mail 14 is formed of an upper channel 14 positioned inversely to and secured to a lower like channel 14 by weldment, and case rail 16 is formed of one channel inverted with respect to drawer rail 12.
Each of the channels is generally C-shaped, having a pair of parallel arms 26 and 28 (see channel 16, FIG. 3) connected by a web Si). At the end of the arms 26 and 28, remote from web 30, is a pair of ilanges 32 and 34. Flange 32 extends outwardly of the channel, while flange 34 extends inwardly of the channel, with outwardly extending ange 32 being slightly offset from inturned llange 34 whereby it is cl-oser to web 26.
The lower portion of drawer rail 12 is telescopically inter-fitted with the upper channel of the suspension rail 14. Further, the upper portion of case rail 16 is ftelescopically interfitted with the 'lower channel of suspension rail 14.
This telescopic intertt-ing denes six ball raceways between the rails, three raceways 40, 42, 44 (FIG. 9) being between the upper drawer .rail and the upper half `of the suspension rail, and three additional race-,ways 46, 48, and S0 being between the lower 'half of the suspension rail and the ease rail. .In the four outermost raceways 40, 42, 48, and Si), two balls are used in each to separate the rails and allow frictionless movement there between. Thus, referring .to FIG. 2, raceway 40 includes balls 54 and 56, raceway 42 includes balls 58 an-d 60, raceway -48 includes balls 62 and 64, and raceway 50 includes -balls 66 and 68.
The two centrally located raceways 44 and 46 each include only one ball; ball 74 at the forward end of upper central raceway 44, and ball 76 at the rear end of the lower central raceway 46. Supplying the additional rolling contacting and spacing means in the central raceways is a disk-shaped propulsion roller 80. This propulsion roller 80 is positioned in a narrow elongated vertical opening extending through the connecting arms of the two channels forming the suspension rail. It is rotatably and irremovably mounted in this position to the suspension rail by an elongated horizontal axle 82 positioned in an elongated horizontal opening drilled crosswise through the connecting arms of the two channels. The propulsion roller cannot become dislodged out of its position or become misaligned even when the drawer rail is extended to the position illustrated in FIG. 1 where the drawer rail is out of contact with the roller and then is pushed back into contact over the roller upon closing the drawing. The upper portion of the roller normally contacts and bears against the lower leg of the drawer rail, while the lower portion of the roller contacts and bears against the upper leg of the case rail.
Movement of the rails with respect to each other during rail extension occurring with opening of the drawer, is limited by a plurality of unique cooperative cushion stops 90, 92, 94, and 96. Stop assembly 90 is mounted to the drawer rail, stop assembly 92 to the upper channel of the suspension rail, stop assembly 94 to the case rail, and stop assembly 96 to the lower channel of the suspension rail.
Stop assemblies 90 and 92 cooperate with each other ast-raddle roller ball 60 in a manner to be described hereinafter. Likewise stop assemblies 94 and 96 cooperate with each other astraddle roller ball 64, when the drawer rail is extended as in FIG. 1. Stop assembly 90 is located approximately in the central section of the drawer rail, stop assembly 92 being located at the front end of the case rail upper portion, stop assembly 95 being located in the centeral portion of the lower channel of the suspension rail, and stop assembly 94 being located at the forward end of the case rail.
Each of the stop assemblies includes two main components, a resilient bumper 100 and a metallic clip 102 (FIGS. 4, 5, and 6). The resilient bumper element 100 is preferably of rubber or rubber-like material, i.e., an elastomer of useful, self-supporting characteristics. It has a generally wedge-shaped nose which tapers diagonally toward the wall of the rail on which it is mounted (see for example the drawer rail wall 104 shown in FIG. 6). The tapered face 106 is at an angle of about 45 degrees, more or less, with respect to the face of wall 104. The resilient bumper has a transverse slot 108 (FIG. 4) and an elevated rear portion 110I to interiit with a generally C-shaped portion of clip 102, with leg 112 of the C-shaped portion being foreshortened. The rearwardly protruding tail or leg 114 of the clip extends into a slot formed by severing parallel slits into the rail wall, and deforming a tab 116 inwardly of the rail wall 104. Insertion of the tail 114 yof clip 102 within the slot under this tab causes the C-shaped portion of the clip facing the wall to retain the rubber bumper against the wall. The rubber bumper may also be adhered to the wall with a suitable adhesive.
A force in the direction of the arrow illustrated in FIG. 6 by a ball on the tapered face 106 of the rubber bumper causes the rear face 118 of the slot in the bumper and the back end 120 of the rubber bumper, to bear against the transverse sufaces of the clip, preventing movement of the stop assembly. Movement is also limited by contact of the C-shaped portion with tab 116. Each of these stops or stop assemblies therefore is within one of the raceways. Preferably these particular raceways 42 and 48 are slightly larger (FIG. 8) and accommodate slightly larger roller balls.
When the drawer is opened to extend the drawer rail assembly, stop assembly 90 moves toward stop assembly 92, and stop assembly 96 moves toward stop assembly 94. Referring to FIG. 7, the two cooperative stop assemblies 90 and 92 move to a position straddling the intermediate roller ball 60 (see FIG. l) so that the ball is pressed between the two diagonal surfaces of the rubber bumper elements. This creates a force perpendicular to the tapered faces of the bumper elements, such that the force applied creates a pressure forcing the rubber bumper elements tightly against the walls of the respective rails. Consequently, instead of a potential shearing action occurring on the stops, a greater force merely increases the resistance 0f the elements, to thereby effect a unique and dependable stop assembly. The resilient bumpers substantially eliminate all noise normally occurring, and also the jarring vibrations when the suspension rail is suddenly pulled to the limit. While extension of the drawer rail with respect to the case rail is limited by this cooperation between assemblies and 92 over ball 60, extension of the suspension rail with respect to the case rail is limited by stop assemblies 94 and 96 astraddle ball 64.
As a safety factor, in case of possible failure of the resilient stop elements, supplemental metallic stop assemblies are employed in a manner such that these do not normally engage, but may in case of slight overextension of the drawer rails. Thus, referring to FIG. l, a boss is slit on one edge and deformed from the rear portion of the suspension rail, and a corresponding reversed boss 132 is deformed from the center portion of the case rail. Likewise (referring to FIG. 1) a boss 134 is deformed from the rear of the drawer rail, while a cooperative boss 136 is deformed from the central portion of the upper channel of the suspension rail. The position of these bosses during the closed drawer position of the rails is illustrated in FIG. 2. Each of these stops is basically of a semi-conical configuration (see FIG. 9). Bosses 130 and 132 are on opposite sides of ball 62, while bosses 134 and 136 straddle ball 58. Each of the bosses protrude inwardly into the raceway, as shown in FIG. 9, so that with the ball positioned between the bosses, they can abut the ball and prevent further movement. Normally these bosses do not move close enough to abut the intermediate ball (see FIG. 1), and only do so in case of failure of the previously resilient stops abutting to prevent significant accidental over-extension of the support assembly. In FIG. 9 the bosses 136 and 132 are shown in phantom, as well as the balls cooperative therewith, to illustrate the cooperative action therebetween.
This invention provides for the iirst time, as far as is known, a quietly operating, dependable, stable, safe, cushioned action eliminating jarring of the frame and providing dignity to the operation of the case drawers. 'I'he assembly actually achieves, simultaneously, the usually incompatible features of (l) resilient cushioned stop means and (2) safety and structural stability. Various additional advantages will undoubtedly occur to those skilled in this art upon studying the foregoing form of the invention, and the principles applicable thereto. It is conceivable that certain minor modications could be made in the particular structural arrangement depicted as the exemplary form of the inventive concept, without departing from the principles taught. Consequently, the invention should be accorded reasonable protection not limited to the particular structural form presented, but only by the scope of the appended claims and the reasonably equivalent structures to those defined therein.
1. In a drawer suspension support comprising: a case rail, a suspension rail, and a drawer rail; said case rail and said drawer rail each being telescopically received by portions of said suspension rail; anti-friction means separating said drawer rail from said suspension rail including at least one ball, and separating said suspension rail from said case rail including at least one ball; a pair of cooperative resilient stop elements mounted respectively to the walls of said drawer rail and suspension rail on opposite sides of one of said balls, and a second pair of cooperative resilient stop elements mounted respect-ively to the walls of said suspension rail and case rail on opposite sides of the second one of said balls; said stop elements being placed in straddling abutment with said balls upon extension of said support; and each of said stop elements having a wedge-shaped nose to cooperate wit-h the adjacent wedge shaped nose of the cooperative stop element and wedge a ball therebetween, thereby pressing the resilient stop elements tightly against the walls of said rails; said rails including metallic safety stops severed and deformed to cooperate and form a pair of cooperative safety stops between said case rail and suspension rail, and ra second pair of cooperative safety stops between said suspension rail and drawer rail; said safety stops being spaced to normally be free of operative engagement except upon slight over-extension of said support with failure of said resilient stops.
2. The support in claim 1 wherein each resilient stop elements includes a bumper with a slot engaged with a generally C-shaped portion of a metallic clip, the other end of said clip having a tail slidably secured under a tab severed Iand deformed from the wall of the respective rail to form a receiving slot.
3. In a drawer suspension support comprising: a case rail, a suspension rail, and a drawer rail; said case rail and said dr-awer rail each being telescopically received by portions of said suspension rail; anti-friction means separating said drawer rail from said suspension rail including at least one ball, and said suspension rail from said case rail including at least one ball; a pair of resilient stop elements mounted respectively to the walls of said drawer rail and suspension rail on opposite sides of one of said balls, and a second pair of resilient stop elements mounted respectively to the walls of said suspension rail and case rail on opposite sides of the second one of said balls; said stop elements being placed in straddling abutment with said balls with extension of said support; each of said stop elements having a resilient bumper with a ball-contacting surface tapered toward the wall upon which the stop element is mounted, to cause a portion of the abutment force to press the bumper tightly against the wall for stability; said bumpers each having a slot in its outer portion, spaced from said tapered surface; a generally U-shaped, metallic holding clip elements engaged in said slots of said bumpers, and having a tongue extending therefrom away from said bumper; a t-ab severed and deformed from the respective rail wall and slidably receiving said tongue to anchor the bumpers against movement with impact.
4. In a drawer suspension support comprising: a ease rail, a suspension rail, and a drawer rail; said case rail and said drawer rail being telescopieally received by said suspension rail; a first pair of cooperative resilient stop assemblies mounted to said case rail and suspension rail and having cooperative elastomeric bumpers providing cushioned stop action; a second pair of cooperative resilient stop assemblies mounted to said suspension rail and drawer rail and having cooperative elastomeric bumpers providing cushioned stop action; a pair of safety stops between said drawer rail and suspension rail and a second pair of safety stops between said suspension rail and case rail; said safety stops normally being out of operative engagement with extension of said support, except with slight over-extension thereof upon failure of said resilient stops.
References Cited by the Examiner UNITED STATES PATENTS 1,068,375 7/13 Watson et al 312-339 1,135,235 4/15 Weiss 312-339 1,227,939 5/ 17 Sampson et al 312-339 X 2,012,530 8/35 Eustis S12-335 2,056,407 10/ 36 Metcalf 312-335 2,559,380 7/51 Wikman e 312-348 X 3,009,755 11/61 Rackow 312-339 FOREIGN PATENTS 122,359 9/ 46 Australia.
FRANK B. SHERRY, Primary Examiner.
CHANCELLOR E. HARRIS, Examiner.