Steel Racking Apparatus

Abstract

This invention relates to an apparatus for racking structural steel stock characterized by at least two upstanding partition-forming wall sections interconnected in longitudinally-spaced parallel relation. Each of these wall sections carries one or more upwardly-opening saddles which, along with the carriage atop which it is mounted, defines a cradle movable relative thereto in load-supporting relation between a retracted and an extended position. A common longitudinally-extending crankshaft interconnects two or more of the longitudinally-aligned cradles together for simultaneous movement so as to produce therewith an open-ended top-loading drawer adapted to support structural steel members and the like at spaced points therealong. In the preferred embodiment, the cradle carriages rest atop the crankshaft in frictional engagement therewith while in two alternative embodiments, the crankshaft is operatively connected to the cradle by a meshed rack and pinion. In one of the latter embodiments, a separate crankshaft is provided for each drawer while in the other an axially-movable shaft is selectively connectable to a pair thereof.

Description

The racking, storage and removal of relatively long, heavy steel structural members and the like has always been a troublesome and time-consuming job which, in most instances, eventually comes down to a simple hand operation where one or more persons manually push or pull the pieces one-at-a-time in and out of a pigeonhole rack. The larger or longer pieces which cannot be handled manually even with the aid of a crane are usually stored on the floor atop blocks that provide the space for passing the crane sling therebeneath. This, of course, is most wasteful of storage space in the warehouse as the area above the steel thus stacked must be left clear for the overhead crane. The shorter pieces capable of being handled manually are, as previously stated, customarily pigeonholed according to their type, size and length.

It has now been found in accordance with the teaching of the instant invention that the many shortcomings of the above-described and other methods of racking steel can, in large measure, be eliminated through the use of the novel top-loading rack forming the subject matter hereof. The present rack is made up of two or more upstanding partition-forming wall sections that are interconnected in fixed-spaced parallel relation. The number and spacing of the partition-forming wall sections are determined by the load and length of the structural members to be stored therein. The actual open-ended top-loading drawers are formed by operatively interconnecting the extendable cradles together for conjoint movement in longitudinally-aligned relation by a common crankshaft. One end of the rack is provided with a special end wall fitted to carry the crank used selectively to turn the crankshafts which operate the drawers. Two or more such drawer assemblies are preferably located on each side of each storage rack, all of which are independently accessible from an overhead traveling crane or similar portable hoisting apparatus such as a forklift truck. All of the cradle elements forming a part of a given drawer are extended and retracted simultaneously by a crankshaft that remains within the confines of the fixed supporting structure where it is protected from damage. The drawers are bottomless, topless and open-ended, the cradles merely supporting the steel at longitudinally-spaced points along its length while confining it against lateral movement.

In the preferred form of the invention, the crankshaft is held in tight frictional engagement with the underside of the several cradle carriages by the weight thereof along with the load carried thereby. A second version of the invention moves the crankshafts to a position over the upper running surface of the rail rather than below and utilizes a rack and pinion to operatively interconnect the crankshaft and long arm of the cradle carriage. Separate drives are provided, however, for each of the drawers. In a third embodiment of the invention, the crankshaft is centrally located and axially-movable so that it can selectively engage and operate a back-to-back set of drawers. In this latter embodiment, a novel mechanical clutch arrangement connects the crankshaft with one cradle carriage arm while disengaging it from the others.

It is, therefore, the principal object of the present invention to provide a novel and improved structural steel storage rack.

A second objective of the invention herein disclosed and claimed is to provide an apparatus for racking steel and the like which includes a series of two or more longitudinally-aligned cradles operatively interconnected by a common crank-shaft for conjoint movement to define an open-ended top-loading drawer.

Another object of the invention herein disclosed and claimed is to provide apparatus of the class described which virtually eliminates the manual operations normally associated with storing steel in pigeonhole racks.

Still another objective of the within described invention is the provision of a rack which provides multi-level steel storage for even those structural elements which ordinarily are too heavy to be loaded by hand and therefore, are stored in single layers at or near ground level.

An additional object of the invention forming the subject matter hereof is to provide a steel storage rack that includes two or more partition-forming wall sections that can be interconnected in longitudinally-spaced parallel relation to define bays of any desired length and load carrying capacity.

Further objects are to provide a steel storage rack that is simple, inexpensive, safe, easy to operate, versatile, rugged, efficient, trouble-free, dependable, easy-to-service, compact and even somewhat decorative in appearance.

Other objects will be in part apparent and in part pointed out specifically hereinafter in connection with the description of the drawings that follows and in which:

FIG. 1 is a side elevational view of one of the partition-forming wall sections of the structural steel storage rack, portions thereof having been broken away to better reveal the interior construction;

FIG. 2 is a side elevation, the center portion of which has been broken away to conserve space, showing how two adjacent partition-forming wall sections cooperate with one another to define a bay;

FIG. 3 is a fragmentary section taken along line 3--3 of FIG. 2;

FIG. 4 is a side elevational detail to an enlarged scale showing the construction of the cradle;

FIG. 5 is a still further enlarged fragmentary end view, portions of which have been broken away and shown in section, revealing the details of the crankshaft and hollow cradle rail subassemblies;

FIG. 6 is an end view of the rack to a reduced scale showing the end wall structure journalling the crankshafts and the crank selectively connectable thereto;

FIG. 7 is a fragmentary side elevation of the end wall, crankshafts and crank of FIG. 6 and to the same scale as the latter;

FIG. 8 is a front elevation of the crank subassembly to a greatly-enlarged scale, portions of the housing having been broken away to reveal the interior construction;

FIG. 9 is a fragmentary side elevation to the same scale as FIG. 8 showing the crank mounted on one of the uprights of the end wall, portions of the latter having been broken away and shown in section;

FIG. 10 is a fragmentary elevation to the same scale as FIG. 8 and FIG. 9 looking to the left at the latter so as to see the pin and bracket retaining means for the crank as it would appear from the inside of the end wall upright;

FIG. 11 is a fragmentary view similar to FIG. 1 but to a much larger scale showing an alternative construction in which a rack and pinion connection is used to form the operative connection between the crankshaft and cradle carriage, portions of the rail having been broken away and shown in section to better reveal the interior construction;

FIG. 12 is a fragmentary top plan view of the alternative structure of FIG. 11 and to the same scale as the latter, portions again having been broken away to reveal the interior construction;

FIG. 13 is a fragmentary view much like FIG. 11 and to the same scale showing a still further modified driving connection between the cradle carriage and crankshaft, portions of the supporting rail having once again been broken away to reveal the rack and pinion;

FIG. 14 is a fragmentary top plan view much like FIG. 12 and to the same scale but showing the modification of FIG. 13 with appropriate portions broken away and shown in section; and,

FIG. 15 is a fragmentary section taken along line 15--15 of FIG. 14 revealing the mechanical clutch used to selectively engage one of the pinions upon axial movement of the crankshaft.

Referring next to the drawings for a detailed description of the present invention and, initially, to FIGS. 1 through 5 for this purpose, reference numeral 10 has been chosen to broadly designate the steel storage rack in its entirety while numeral 12 similarly identifies the fundamental building blocks of the system, namely, the upstanding partition-forming wall sections which, in the particular form illustrated, are interconnected in fixed-spaced parallel relation by spacers 14 and crossed diagonal struts 16. Two or more longitudinally-extending feet 18 arranged in transversely-spaced relation to one another cooperate with a bedplate or the like 19 to provide a base atop which is mounted the lowermost pair of several pairs of load-supporting rails 20 that comprise a part of each partition-forming wall section. In the particular form illustrated, the rails are mounted in side-by-side spaced parallel relation. Each rail of the pair defines the supporting structure upon which one of the cradle subassemblies that have been broadly identified by reference numeral 22 rides as it moves between its retracted position shown in full lines in FIG. 1 and the extended position thereof shown in phantom lines. One rail carries the cradle emerging from the right side of the partition-forming section 12 while its companion in the pair carries the one that emerges from the left side. Obviously, if the rack is located where access can be had to but one side thereof, only a single rail 20 is needed at each level to accommodate the cradle that emerges from such side.

Between the pairs of rails on the several levels rises a central vertical supporting column 24. At each level above the first, the rails define crossarms extending horizontally in opposite directions from said central column and upon both faces thereof. Atop the upper end of the column is mounted a fixed upwardly-opening saddle consisting of a crossarm 26 with uprights 28 at opposite extremities thereof. This fixed cradle can, of course, be loaded directly from above and it needn't, therefore, be extendible in drawer-like fashion as is the case with the others.

Projecting from the same faces of the column that carry the rails are tubular brackets 30, two at the top and another two at the bottom. Opposed pairs of these brackets on adjacent partition-forming wall sections telescope into the opposite open ends of the tubular spacers 14 which thus determine the longitudinal spacing therebetween. The weight and stiffness of the members to be loaded in the rack will, in most instances, determine the width of the bays between partition-forming wall sections as they, in turn, determine the unsupported lengths. Angle brackets 32 at the base and top of each column receive diagonal struts 16 which cooperate with the spacers 14 to maintain the fixed-spaced relation between the partition-forming walls.

An examination of FIG. 2 will reveal that all of the cradles 22 are vertically aligned on both faces of the rack although, obviously, they can be staggered from one side of the central column to the other as they progress from top to bottom; however, since no useful purpose would be served by so doing, the construction shown is preferred from a standpoint of simplicity and standardization. Permanently fastened alongside each rail 20 in spaced parallel relation to one another so as to project beyond one of its ends are a pair of identical mounting brackets 34.

Downturned ears 36 of these brackets 34 that project both beyond and beneath the rail contain longitudinally-aligned openings 38 in which are pressed or otherwise fastened shaft journals 40, all of which is most clearly revealed in FIG. 5 to which detailed reference will now be made. A stub shaft 42 is journaled for rotation within bearings 40 and shaft collars 44 on said shaft bear against the exposed faces of ears 36 and prevent relative axial movement thereof. Fastened securely to the portion of stub shaft 42 lying between the bracket ears for conjoint rotation therewith is a friction roller 46. The upper surface of this roller lies essentially tangent to the plane of the lower upwardly-facing running surface of the load-supporting rail so that the underside of the cradle carriage 48 will ride atop thereof as shown when it moves telescopically to and fro inside the latter.

Detachably fastened to the inside faces of the shaft-mounting brackets 34 above the ears 36 depending therefrom are a pair of stops 50 whose adjacent faces are spaced apart a distance less than that which separates the corresponding surfaces of rail 20. A second set of stops 52 (FIGS. 1 and 4) project from the sides of the cradle carriage spaced intermediate the ends thereof in position to engage stops 50 when the drawer subassembly that has been broadly designated by reference numeral 54 lies in the extended position shown in phantom lines in FIG. 1. Note that with stops 50 and 52 engaged, slightly more than half of the cradle carriage 48 still lies confined within rail 20 due to the fact that a portion of this carriage which will be described in detail presently is about the same length as the rail so as to extend all the way to its other end while the drawer pulls out a distance substantially less than half this distance. The net result is that while the load 56 (FIG. 1) within the drawer when it is extended is substantially overbalanced, the roller 46 and the lower of the two wheels 58 journaled on the remote end of the cradle carriage which, at this point, is rolling along the underside of the top wall of the rail, define two widely separated load-bearing points easily capable of resisting the tilting moment about the stub shaft 42. Wheel 58 of the carriage is free to roll along the bottom running surface of rail 20 until the point is reached where the center of gravity of the loaded drawer moves outwardly beyond sleeve 46, whereupon, the cradle tilts the fraction of an inch necessary to lift wheel 58 into contact with the underside of the top wall of the rail. On the other hand, as will be seen presently, wheel 58 may never contact the lower upwardly-facing running surface of the rail which, therefore, is not absolutely necessary although preferred. The corresponding cradle carriage for the drawer at the same level on the opposite face of the rack includes a portion running to and fro in parallel overlapping relation within the companion rail on the other side of the column 24, the latter structure being clearly revealed in FIG. 3.

The carriage has a long lower arm 59 that runs inside the box rail 20. An upright post 60 at the near end of this lower arm forms a part of the upwardly-opening U-shaped saddle that is also a part of the cradle 22. The upper arm 62 of the carriage is shorter than lower arm 59 and it also functions as the bottom or base frame member of the saddle. Upper and lower carriage arms 62 and 59 are arranged in vertically-spaced relation so as to leave a rearwardly-opening slot 64 therebetween sized to receive the top horizontal wall 66 of the rail. Even with the lower carriage arm supported from below as shown by the bottom wall of rail 20, the slot 64 left between it and the upper arm 62 would likely close under heavy loads causing the carriage to drop down onto the top of the rail and thus resist free movement of the cradle between its retracted and extended positions. To prevent this from occurring, the far end of the upper carriage arm 62 is provided with the second of the pair of carriage wheels 68 adapted to run along the top or exposed surface of the top wall 66 of the rail as shown.

The only other element of cradle 22 that remains to be described is rear upright post 70 which is attached in vertical position to the far end of the upper carriage arm 62 adjacent the roller 69 carried thereby. Front and rear posts 60 and 70 cooperate with the connecting upper carriage arm 62 to define an upwardly-opening generally U-shaped saddle adapted to receive the load 56 from above and confine same against lateral movement relative thereto. With the drawer unloaded, wheel 58 on the longer of the two carriage arms will either by rolling along the upwardly-facing running surface on the bottom wall of the rail or the wheel 61 on the upper short carriage arm 62 will be rolling along the corresponding running surface of the top wall 66 but seldom both. When heavily loaded, on the other hand, both carriage wheels 58 and 68 will likely be in rolling contact with running surfaces of the rail. With the center of gravity of the loaded drawer on the inside of roller 46, wheels 58 and 68 will likely be in contact with the upwardly-facing running surfaces of the top and bottom rail walls; whereas, with the load outside roller 46, these same wheels will be in rolling contact with opposite running surfaces of the same rail wall, namely, the top one 66.

Finally, before leaving FIGS. 1-5, it will be seen that each of the several drawer subassemblies 54 comprises a longitudinally-aligned series of two or more cradles 22 operatively interconnected for simultaneous movement in the same horizontal direction by a common crankshaft 72. The several axially-aligned stub shafts 42 of the several partition-forming wall sections comprise sections of the crankshaft 72 to which they are connected in driving relation by shaft couplings 74. These shaft couplings allow for minor alignment errors while transmitting the driving torque from section to section. Thus, when the crank subassembly 76 which will be described in detail presently in connection with FIGS. 6-10, inclusive, is connected to a free end of the crankshaft and employed to rotate same in the appropriate direction, the entire drawer subassembly 54 which may be several bays long and include a plurality of cradles will move in or out as a unit.

Next, with reference to FIGS. 6-10, inclusive, the crank subassembly 76 together with the endwall structure identified broadly by numeral 78 which supports same will now be described in detail. This endwall, in the particular form shown, comprises a frame that includes a pair of uprights 80, a counterpost 82 and several horizontal crossframe elements 84 interconnecting the latter at the level of each crankshaft 72. The endwall thus defined is fastened in fixed-spaced parallel relation to the adjacent partition-forming wall section 12 by the same type of spacers 14, diagonal struts 16 and brackets 32 that are used between two of the latter sections.

The free ends 86 of the crankshafts pass through openings 88 (FIG. 9) in the web of uprights 80 onto the outside surface of frame 78. Each such shaft-receiving opening 88 is provided with at least one, and preferably a pair, of companion openings 90 spaced vertically therefrom. In the case of a pair of such openings 90, one is located above and the other below the shaft as illustrated.

The projecting end 86 of each shaft 72 is squared-off or otherwise shaped to receive the crank tool socket 92 of the crank subassembly 76. Now, depending upon the load that crankshaft 72 has to move, it may be driven directly by a simple handcrank-like dogleg handle 94 of the assembly shown or, in the case of long heavily-loaded shafts, it is preferred to interpose a speed reduction mechanism indicated generally by reference numeral 96.

In the case just mentioned, reducer 96 includes a pair of spaced parallel plates 98 defining a frame. The tool socket 92 is journaled for rotation between these plates and it comprises the hub of sprocket 100. A stub shaft 102 is journaled for rotation in spaced parallel relation to tool socket 92 while mounting thereon the smaller sprocket 104 for conjoint rotation therewith. The projecting end of stub shaft 102 receives crank 94 and sprocket claim loop 106 defines the operative driving connection between the sprockets. By providing the crank subassembly with a speed reduction ratio of somewhere around 2:1 or 3:1, the load on shaft 72 can be handled quite easily.

Now, the inner of the two plates 98 of the reducer is provided with a guide pin 108 that fits into one of the guide pin openings 90 depending upon whether the crank subassembly is used right-side-up as shown in full lines or upside-down as shown in phantom lines in FIG. 6. By enabling the unit to be used upside-down near the floor, clearance is provided to rotate the crank.

The remaining feature of the crank subassembly is U-shaped bracket 110 that slips around the upright 80 and cooperates with the guide pin 108 to hold the unit in proper position. This bracket is, of course, fastened permanently to the rear face of the inside plate 98 in spaced relation to pin 108.

The attention is now directed to FIGS. 11 and 12 where the first of two alternative embodiments have been illustrated. In the preferred embodiment just described, the crankshafts 72 run along the outside faces of the rack and the cradle carriage rests atop thereof in frictional driving engagement therewith. The only disadvantage to this arrangement is the exposed position of these crankshafts which renders them somewhat more vulnerable to damage from external activities being carried on in the immediate vicinity of the rack such as, for example, other steel-handling operations. Thus, while the preferred embodiment of the rack is quite well protected against damage from proper use, it is somewhat more vulnerable to external steel-handling operations such as the movement of forklifts, crane-supported loads, etc.

The embodiment 10m shown in FIGS. 11 and 12 obviates the aforementioned problem by moving the crankshafts 72m in to the central column 24. The stub shafts 42m are somewhat longer and are journaled for rotation within bushings 112 that replace the ball bearing journals 36 of the previously-described embodiment. These stub shafts 42m are coupled in driving relation to shafts 72 by shaft couplers 74 as before. Each such stub shaft, however, carries a pinion gear 114 that turns with said shaft and within a slot 116 in the top wall 66m of slightly modified rail 20m.

While cradle 22m is modified slightly in unimportant details over the one 22 shown in FIGS. 1-5, the only significant change lies in the carriage 48m thereof, the lower arm 59m of which is reduced in depth to accommodate rack 118 fastened atop thereof in position to mesh with the pinion 114 carried by the stub shaft.

Thus, upon rotation of the crankshaft 72m, the rack and pinion connection defines a direct mechanical drive operative to actuate the drawer 58m between its retracted or closed and open or extended positions. The rack 118, of course, need only extend over the rear half of the lower carriage arm 59m as shown.

There are a few other features needed in this embodiment not found in the one previously described. The first, and most significant, of these is carriage-supporting roller 120 journaled for rotation on stub shaft 121 within slot 124 in the lower front corner of rail 20m. In the absence of friction roller 46 of the earlier version, roller 120 is needed to support the underside of the carriage.

Since the inboard location of the crankshafts 72m removes a measure of support for the outer ends of the rails and cradles movable relative thereto that is provided by crankshaft 72 of the previous embodiment, longitudinal stringers 122 are used as shown to replace the latter.

The changes required in endwall 78 (FIG. 6) to accommodate the relocated crankshafts 72m comprise nothing more than eliminating centerpost 82 and relocating uprights 80 in side-by-side parallel relation in the space formerly occupied by the latter. Actually, one could connect the crank subassembly 76 onto a free end of stub shaft 42m as it emerges from column 24 and eliminate the endframe 78 altogether if it were not for the problem of gaining access thereto between the projecting ends of the load when the drawers are closed.

The third version 10n of the unit is that shown in FIGS. 13-15 to which reference will now be made has the same disadvantage as the one shown in FIGS. 11 and 12, namely, it is more complicated and, therefore, more expensive than the preferred embodiment of FIGS. 1-5. In some respects it is quite similar to the version shown in FIGS. 11 and 12 in that the crankshaft 72n runs down the middle and is journaled for rotation in central column 24 rather than being on the outside faces of the rack. Cradle 22n is unchanged over the one in FIGS. 11 12 and the only change in rail 20n is to relocate the pinion opening 116 in the top-wall 66n thereof so that it is longitudinally-aligned with the one in the companion rail of the pair on the opposite side of the post. Here, a single crankshaft 22n journaled within sleeve 118 for both rotational and axially slidable movement is used to selectively engage one or the other of the pinion sets 114a or 114b by means of a clutch mechanism generally indicated by reference numeral 120. Collars 122 attached to each sleeve bracketing the pinions permit free relative rotation thereof.

Now, by moving the crankshaft 72n inward axially (upwardly in FIG. 14) clutch 120a engages pinion 114a to drive the cradle attached to the latter in either direction while clutch 120b disengages and leaves pinion 114b inoperative. Actually, of course, there will be a series of two or more pinions 114a connected to operate the drawer on one side of the rack while a similar set 114b will function independently of the first set to operate the drawer on the opposite side.

Clutch mechanism 120 is intended as being merely illustrative of but one of a number of two-way mechanical clutches capable of selectively turning the pinion sets 114a or 114b in either direction. As shown, the hub 124 of each pinion has a pair of diametrically-positioned ears 126 projecting therefrom which engage, upon relative shaft rotation, a corresponding pair of ears 128 carried by flanged collar 130 mounted on said shaft for conjoint rotation therewith. While conceivably, the pinions 114a and 114b could be moved in and out of direct engagement with the racks 118, the chances of the pinion teeth and rack teeth all being aligned for meshed engagement is rather remote, therefore, mechanical clutches which will operate in spite of such misalignment are preferred. The clutch ears are shaped to cam past one another even when partially opposed and those that are not right together need only a fraction of a turn before they engage and form a driving connection.

Finally, with specific reference to FIG. 14, one type of representative mechanism that can be used to both turn shaft 72n and shift it axially has been shown and identified in a general way by numeral 132. Shaft 72n is mounted for axially-slidable and rotational movement in collar 134. An internally-threaded collar 136 projects inwardly toward the shaft in coaxial relation thereto from plate 98m in which it is journaled. Collar 136 comprises the hub of gear 100m that replaces the sprocket 100 of the FIG. 8 reducer. Crank 94 connects onto gear 104m which meshes with gear 100m and replaces sprocket 104 thus eliminating chain 106. A U-joint 138 connects threaded stub shaft 140 to the projecting end of shaft 72n and also threads through collar 136. By holding shaft 72 stationary and rotating the crank 94 in the proper direction, the gear train will turn collar 136 and either pull out or push in shaft 72n by means of axial movement of stub shaft 140 until the selected set of clutches 120 and their pinions 114 are engaged, whereupon, pin 142 in the collar 136 is slipped into one of two axially-spaced openings 144 in the stub shaft to lock these elements together for further conjoint rotational movement in either direction. The reducer 96m is maintained in fixed spaced relation to the adjacent endwall 78m by spacers 146. Thus, a single crankshaft 72n can be used to selectively actuate the drawers on either side of the rack.

In the interests of simplicity of illustration, a unitary shaft 72n has been shown, however, in actual practice a jointed shaft like that previously described could, and probably would, be used to lessen the alignment problems. The latter embodiment, while eliminating half of the crankshafts, is the most complicated of the three and, therefore, the least desirable.

Claims

What is claimed is:

1. The steel storage rack which comprises: two or more upstanding partition-forming wall sections mounted in fixed-spaced parallel relation to one another, two or more of said sections having one or more rails mounted thereon, one or more rails of each section lying in longitudinally-spaced parallel relation to at least one rail of at least one other section to define at least a pair thereof, the rails of each pair including load-bearing means defining an upwardly-facing horizontal running surface and a downwardly-facing running surface paralleling the latter located therebeneath; a carriage mounted on each rail of the pair for independent longitudinal movement relative thereto in transversely-spaced parallel relation to one another, said carriage including upper and lower rigid arms connected together at their near ends vertically-spaced relation to define a gap therebetween sized to receive the load-bearing means and a pair of anti-friction members carried by said arms for movement therewith in rolling engagement with the running surfaces of said load-bearing means, said anti-friction members being positioned to cooperate with one another and resist a load displaced toward the near end of the carriage tending to tilt the latter downwardly; a pair of upright posts fastened to the upper arm of the carriage so as to cooperate therewith to define an upwardly-opening generally U-shaped saddle adapted to cradle a load lowered therein; roller means journaled for rotation adjacent the near end of the rail in supporting relation to the underside of the carriage; and, means operatively interconnecting two or more carriages together for simultaneous movement in the same direction between a retracted and an extended position, said means cooperating with said carriages and with the cradle-forming saddles atop thereof to produce an open-ended drawer.

2. The steel storage rack as set forth in claim 1 in which: the anti-friction member on the lower of the carriage arms is spaced farther from the near end thereof than the other of said members carried by the upper arm.

3. The steel storage rack as set forth in claim 1 in which: stop-forming means are carried by the rail and carriage in position to interengage and limit the extended position of the latter.

4. The steel storage rack as set forth in claim 1 in which: the means operatively interconnecting the carriages for simultaneous movement comprises a shaft connecting the carriage-supporting rollers together for conjoint rotation.

5. The steel storage rack as set forth in claim 1 in which: the means operatively interconnecting the carriages together for simultaneous movement comprises a rack carried by each of said carriages extending longitudinally thereof, a shaft journaled for rotation between the partition-forming wall sections extending transversely across said racks in juxtaposed relation thereto, and pinion gears mounted on said shaft for conjoint rotation therewith in meshed engagement with each of said racks.

6. The steel storage rack as set forth in claim 1 in which: two or more of the partition-forming wall sections include at least one pair of rails mounted in side-by-side parallel relation at the same level, one rail of one pair cooperating with a rail of another pair at the same level to mount carriages extendible on one side of the partition-forming sections while the remaining rails of said pairs cooperate to mount carriages opening into extended position on the opposite side of the latter.

7. The steel storage rack as set forth in claim 1 in which: two or more partition-forming wall sections are provided with two or more rails stacked one above the other in vertically-spaced parallel relation, at least two rails at each level cooperating with one another to mount the carriages of a single drawer.

8. The steel storage rack as set forth in claim 1 in which: the lower carriage arm is substantially longer than the upper carriage arm; the anti-friction members are mounted on the far ends of both arms; and, stop means are carried by the rail and carriage located to interengage upon movement of the latter toward extended position so as to leave the anti-friction member carried by the upper carriage arm in rolling load-supporting contact with the upper running surface.

9. The steel storage rack as set forth in claim 1 in which: the rail is of hollow rectangular configuration, the top wall of said rail defining the load-bearing means and the bottom wall thereof comprising a second load-bearing means defining a second upwardly-facing running surface positioned to receive the anti-friction member on the far end of the lower carriage arm for rolling engagement atop thereof when telescoped within said rail.

10. The steel storage rack as set forth in claim 1 in which: the partition-forming wall sections include a centrally-located vertical column with the rails mounted thereon in vertically-spaced parallel relation so as to project on opposite sides thereof and define crossarms; the lower arm of the carriage is of a length adapted to extend to substantially the far end of the rail when in retracted position and the upper arm thereof is substantially shorter than the lower; and, in which the anti-friction members are mounted at the far ends of their respective carriage arms.

11. The steel storage rack as set forth in claim 1 in which: the rail includes a second horizontal load-bearing surface located in fixed-spaced parallel relation beneath the first, said second load-bearing surface defining a second upwardly-facing running surface positioned to cooperate with the first and divide the load on the carriage when a load is cradled in the saddle atop thereof.

12. The steel storage rack as set forth in claim 2 in which: the length of the rail is approximately twice the length of the drawer supported thereon; and, in which the lower carriage arm is approximately the same length as the rail upon which it rides.

13. The steel storage rack as set forth in claim 5 in which: the lower arm of the carriage projects a substantial distance beyond the far end of the upper arm thereof; the shaft and pinions carried thereby are journaled for rotation beyond the far end of the upper carriage arm when the latter is in retracted position; and, in which the rack is mounted atop the projecting portion of the lower carriage arm.

14. The steel storage rack as set forth in claim 6 in which: the carriages supported for extendible movement in opposite directions on each side-by-side pair of rails include overlapping extensions paralleling one another in the same horizontal plane; racks are mounted on the overlapping extensions of each carriage; a single crankshaft is journaled for rotational movement in juxtaposed position to said racks and for horizontal axial movement in a direction normal thereto; one pinion is mounted on the shaft for both rotational and axial movement relative thereto in permanent meshed engagement with each rack; and, in which clutch means are carried by said pinions and shaft selectively operative in one axial position of the latter to form a driving connection with a set of two or more pinions meshed with the carriage racks of a single drawer, and said clutch means being alternatively operative in a second axial position of said shaft to form a driving connection with a second set of two or more pinions meshed with the carriage racks of another drawer opening onto the opposite side while disengaging said first set of pinions.

15. The steel storage rack as set forth in claim 6 in which: two or more partition-forming wall sections are provided with two or more rails stacked one above the other in vertically-spaced parallel relation, at least two rails at each level cooperating with one another to mount the carriages of a single drawer.

16. The steel storage rack as set forth in claim 6 in which: the carriages at the same level cooperate with the cradle-forming saddles carried thereby and their respective crankshafts to define back-to-back drawers opening in opposite directions.

17. The steel storage rack as set forth in claim 13 in which: the upper load-bearing means includes a slot opening above the rack therebeneath and the pinion engages the rack through said slot.

18. The steel storage rack as set forth in claim 14 in which: a stationary portion of said rack carries means connectable to said shaft for releasably locking same in either of its operative axial positions.

19. The steel storage rack as set forth in claim 14 in which: the shaft includes an externally-threaded section adjacent a fixed part of the rack; an internally-threaded nut-forming element is carried by said fixed part of the rack in threaded engagement with the threaded shaft section; and, means for selectively fastening said nut-forming element to said shaft and rack, said means when activated to stay in fixed relation to said rack becoming operative to shift the shaft axially between its operative positions upon rotation thereof, and said means when connected to the shaft for conjoint rotation therewith defining the drive coupling for rotating same in either direction relative to the rack.