US3406845A

US3406845A - Method and apparatus for racking steel with a single hook hoist

Info

Publication number: US3406845A
Application number: US512606A
Authority: US
Inventors: Thomas D Fahey
Original assignee: Steel Inc
Current assignee: Steel Inc
Priority date: 1965-12-07
Filing date: 1965-12-07
Publication date: 1968-10-22
Anticipated expiration: 1985-10-22

Description

5 Sheets-Sheet l INVENTOR. THOMAS D. FAHEY ATTORNEYS Oct. 22, 1968 FAHEY METHOD AND APPARATUS FOR BACKING STEEL WITH A SINGLE HOOK HOIST Filed Dec. 7, 1965 T. D. FAHEY METHOD AND APPARATUS FOR BACKING STEEL WITH A SINGLE HOOK HOIST 5 sheets-sheet 2 INVENTOR. THOMAS D. FAHEY oot ATTORNEYS Oct. 22, 1968 Filed Dec.

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Oct. 22, 1968 T. D. FAHEY 3,406,845

METHOD AND APPARATUS FOR BACKING STEEL Filed Dec. 7, 1965 WITH A SINGLE HOOK HOIST 5 Sheets-Sheet 5 F IG. 9. 36- 3 INVENTOR. THOMAS D. FAH EY ATTORNEYS United States Patent 3,406,845 METHOD AND APPARATUS FOR BACKING STEEL WITH A SINGLE HOOK HOIST Thomas D. Fahey, Denver, Colo., assignor to Steel, Inc., Commerce City, Colo., a corporation of Colorado Filed Dec. 7, 1965, Ser. No. 512,606 Claims. (Cl. 214-16.4)

ABSTRACT OF THE DISCLOSURE This invention relates to an apparatus for racking steel which is an improvement over that forming the subject matter of US. Patent No. 3,138,266, of which I was a joint inventor, in that: (1) It utilizes a single hook hoist rather than a double hook one; (2) the need for specially-designed racks is eliminated; (3) the apparatus is fastened to the rack only at the rear end of the pigeonhole; (4) means are provided for balancing the load; and (5) remotely-actuated means are provided for operating the clamp that fastens the unit to the rack. In addition, the instant invention contemplates an improved method of using the apparatus that includes the steps of balancing the load and fastening same to the rear of the rack while leaving the apparatus disconnected from the front thereof.

This invention relates to a method and apparatus for racking steel and it constitutes an improvement over our US. Patent No. 3,138,266 bearing the same title.

In our earlier patent above-identified, a double-hook crane was employed to lift and move the apparatus carrying the load of steel to the appropriate pigeonhole-in the rack. One crane hook was fastened adjacent the front end of the load-carrying apparatus and the second rear- Wardly of its midpoint.

The load-carrying apparatus included a tray member beneath which the load was suspended and a track assembly within which the tray moved longitudinally. The front crane hook attached to the tray provided the means for moving same inwardly on the track into load-discharging position within the pigeonhole. The rear crane hook also engaged the tray and, of necessity, had to be unfastened during the load-discharging operation.

It became possible to unfasten the rear crane hook because the track fastened to two l0ngitudinallyspaced transversely-extending elements of the rack and thus supported the tray during its excursion into the pigeonhole.

It has now become apparent that this patented apparatus possesses certain inherent deficiencies that place severe restrictions on its utility and versatility. To begin with, the apparatus required the use of a double-hook crane which is an expensive and relatively rare piece of equipment in most steel warehousing and fabricating facilities. More significant, however, was the fact that the racks themselves had to be specially designed and constructed to provide the extremely accurate transverse frame element spacings required to fasten the track thereto at two different points.

In retrospect, it becomes rather apparent that most steel fabricators and warehousers already have their racks built and, for economic reasons, are most reluctant to tear them out and reinstall new ones designed to accommodate the patented apparatus. New construction and the expansion of existing facilities, of course, creates potential users but this is a small segment of the overall potential in an industry that has need of such apparatus. Even newcomers to the industry might find it difficult to justify the increased capital outlay required to purchase a double-hook overhead crane instead of the less expensive single-hook variety.

The problem became, therefore, one of attempting to Patented Oct. 22, 1968 ice change the method and redesign the apparatus so it would function with existing racks and require only a single hook crane. The first difficulty encountered was one of load-balancing. A double-hook crane presents no balancing problems because it is only necessary to locate the points of attachment on opposite sides of the mid-point to substantially eliminate any bothersome imbalance. A single-hook crane, on the other hand, must have its point of attachment located almost exactly above the balance point if the apparatus is to function as intended. Also, this point varies from load-to-load because of the inconsistency thereof. In other words, when picking up a bundle of rods, their extremities are seldom, if ever, precisely aligned nor is it practical to position to crane and racking apparatus relative to the load with any great degree of precision. Accordingly, it became necessary to equip the apparatus with a mechanism whereby the pickup point could be adjusted longitudinally to coincide with the balance point once the load was in place.

The next problem was one of adapting the apparatus to fasten securely onto existing racks. There was no difficulty experienced in getting the latch mechanism to accommodate the various rack element shapes, but rather, to design a remote actuating system by means of which the lock located at the extreme rear end of the track could be operated from the accessible end of the pigeonhole into which the load would be introduced.

In addition to the above changes, a number of improvements were made in the load-supporting, cable fastening and release mechanisms, safety latches and the like. All in all, the improved design provides a much more versatile unit as well as one that is considerably less expensive to install despite the fact that the basic principles involved in pigeonholing and releasing the load remain substantially unchanged.

It is, therefore, the principal object of the present invention to provide a novel and improved method and apparatus for racking steel.

A second objective is to provision of apparatus of the type aforementioned that is designed for use with existing pigeonhole racks and requires only a single hook crane.

Another objective is to provide a unit of the character described that incorporates a novel load-balancing mechanism.

Still another object is the provision of a steel-racking system that can be operated by one man efiiciently and safely.

An additional object of the invention hereindisclosed and claimed is the provision of a pigeonholding unit which will accommodate loads of varying lengths, thicknesses, weights and shapes with equal facility.

Further objects are to provide a steel-racking device that is rugged, relatively inexpensive, easy to use, trouble-free, compact and capable of bringing about substantially reduced labor costs.

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:

FIGURE 1 is a top plan view of the racking apparatus, portions of which have been broken away to conserve s ace;

FIGURE 2 is a side elevation of the racking apparatus showing same attached to a rack, portions having once again been broken away to conserve space;

FIGURE 3 is a bottom plan view to a slightly enlarged scale showing the load-supporting tray alone;

FIGURE 4 is a fragmentary longitudinal section further enlarged and taken along line 4-4 of FIGURE 3 revealing the details of the load-supporting cable housing;

FIGURE 5 is a fragmentary longitudinal section taken 3 along line 55 of FIGURE 1 and enlarged to clearly reveal the rack-latching subassembly;

FIGURE 6 is an enlarged vertical section taken along line 6-6 of FIGURE 2;

FIGURE 7 is a front end elevation to an enlarged scale;

FIGURE 8 is an enlarged fragmentary section showing the cable-release subassembly;

FIGURE 9 is a section taken along line 9-9 of FIG- URE 8;

FIGURE 10 is a section taken along line 1010 of FIGURE 8; and

FIGURE 11 is a fragmentary detail, portions of which have been broken away and sectioned, showing the latch mechanism by which the tray and track are releasably locked together.

Referring now to the drawings for a detailed description of the present invention and, initially, to FIGURES 1-3, inclusive, for this purpose, reference numeral 10 has been employed to designate the racking apparatus in its entirety, numeral 12 the single-hook crane, numeral 14 the load, and numeral 16 a standard pigeonhole rack. The rack comprises nothing more than a plurality of .bays or pigeonholes 18 formed by front and rear sets of

groundanchored uprights

20 and 22 interconnected by horizontal load-carrying members 24 arranged in longitudinally and vertically-spaced parallel relation to one another. In the particular form illustrated, these load-carrying elements comprise solid rods having a circular cross-section, however, they may take the form of pipes, channels, I- beams, angle-irons, T-beams, etc. and still function perfectly well with the racking apparatus 10, the only requirement being that the rack-latching mechanism indicated in a general way by reference numeral 26 be designed to accommodate same. In the patented double-hook version of the racking apparatus previously discussed, the longitudinal spacing between the elements 24 which supported the load in any given pigeonhole or bay was quite critical because it was necessary to fasten the track subassembly to both of these rack elements before the rear hook could be released. With the instant racking apparatus, on the other hand, no such precision is required because the track subassembly 28 fastens only to the rearmost rack element 24 as shown in FIGURE 2 and operates independently of the front one, the crane 12 providing the means for supporting the racking apparatus and a substantial portion of the load at all times. In other words, the only time the rack carries any load is during the actual movement of the steel into the pigeonhole with the tray subassembly, the latter having been broadly designated by reference numeral 30, because, at this time, the racking apparatus moves from a balanced condition to a condition of imbalance due to a shift in the load toward the rear end thereof.

At this point it might be well to digress for a moment and point out that in the descriptive material which follows as well as that set forth previously, the front end of the rack has been designated the one into which the load is introduced. To be consistent, therefore, the front end of the racking apparatus is the one nearest the operator at which end is located the load-release actuator 32, the chains 34 that take up the slack in the loadsupporting cables 36, and the

safety catches

38 and 40 that control operation of the latter. Thus, the load will move into the pigeonhole rear-end-first.

FIGURES 1, 2, 5 and 6 show the track subassembly 28 most clearly and it is to these figures to which reference will now be made. The track includes a pair of channel-shaped rails 42 arranged in transversely-spaced parallel relation with their channels opening toward one another as best seen in FIGURE 6. A plate 44 bridges the rails at the rear extremities thereof and is welded or otherwise fastened to the upper flanges so as to not obstruct the movement of the tray, load-carrying cables and load which must run freely therebetween. A similar plate 46 is provided near the front end of the rails in bridging relation thereto as seen in FIGURES l and 6. One or more additional bridge-plates 48 may be provided at longitudinally-spaced points between

plates

44 and 46 which cooperate with the latter to maintain a fixed-space relationship between the rails, one of said additional plates having been illustrated.

Mounted atop plate 44 at the rear end of the track is the fixed element 50 of the rack-latching subassembly 26. As shown, element 50 is provided with an overhanging lip 52 shaped to hook over the rear of load-supporting rack element 24 after having been lowered to pass therebeneath, raised and brought forward into contact therewith. Lip 52, is, of course, shaped as required to hook over the particular type of load-carrying frame element 24 used in the customers racks.

Plate 44 alSO mounts a pair of inverted generally L- shaped guide shoes 53 that receive the side margins of the cross-bar portion 54 of T-shaped reciprocating member 56 for longitudinal slidable movement therebetween. The rearmost edge of cross-bar portion 54 carries the movable element 58 of the latch subassembly 26 that cooperates with element 50 thereof to releasably fasten to the load-carrying rack element 24 as shown in FIG- URE 2. As revealed in FIGURE 2,

elements

50 and 58 are substantially identical with the latter being shaped to hook over the top of round rod 24 from the front. or viously, when frame elements 24 are employed in the rack that have cross-sections that are not circular, the shapes of

elements

50 and 58 will be altered accordingly and, in many instances, the specific shapes of these fixed and movable elements of the latch subassembly will differ from one another to accommodate the different rack element surfaces they must engage and hook onto.

Now, reciprocating motion of T-shaped member 56 to move latch element 58 relative to its counterpart 50 between latched and released positions must be accomplished from a remote position if the apparatus is to be practical. If it were otherwise, the operator would have to move all the way around to a position behind the rack in order to actuate the latch subassembly 26 having prepositioned the racking apparatus 10 relative to the rack as shown in FIGURE 2 except that the latch mechanism would be in retracted or released position. Of necessity, therefore, the latching operation must be one that can be accomplished from a position out in front of the rack.

T-shaped member 56 provides the means by which the remote actuation of the latch element 58 can be taken care of from out in front of the rack. Bridgeplate 48 located

intermediate plates

44 and 46 is provided with an inverted U-shaped member 60 forming a tunnel through which the stem portion 62 slides and is guided. The front end of stem 62 slides atop plate 46 and is provided with a rack 64, the teeth of which project upwardly therefrom.

The load-balancing subassembly that has been identified in a general way by reference numeral 66 includes as a part thereof a pair of longitudinally spaced

parallel plates

68 and 70 that extend transversely between the rails 42 and project upward vertically therefrom. As seen in FIGURE 6, these plates are generally pentagonal having a horizontal bottom edge bridging the gap between the rails, vertical side edges, and upwardly and inwardly inclined margins cooperating to form an inverted V- shaped top edge. The vertex of this inverted V-shaped top edge lies spaced above the longitudinal centerline of the racking apparatus and these vertices are jointed together by a connecting bar 72 that cooperates with

plates

68 and 70 to define a saddle. Plate 68 is located as shown adjacent the front extremities of the rails while plate 70 is spaced rearwardly therefrom.

Returning once again to the rack latching subassembly 26, the front saddle plate 70 provides the supporting structure for the various elements of the latch-operating mechanism that will now be described. A pair of forwardly projecting transversely-spaced cars 74 attached to the front face of plate 70 receive shaft 76 for rotational movement therebetween. Opposite ends of the shaft 76 are provided operating handles 78 which enable the latch subassembly 26 to be actuated from either side of the racking unit Also mounted on shaft 76 for rotation therewith is a pawl 80, thet teeth 82 of which mesh with the teeth of rack 64 and bring about reciprocating movement of T-shaped member 56 that carries the movable latch element 58 on its rear extremity. As revealed most clearly in FIGURE 5, the teeth of pawl 80 do not completely encircle same and a shoulder 84 is provided on its cylindrical surface opposite said teeth. A locking dog 86 mounted on shaft 88 which rotates between cars 90 cooperates with shoulder 84 to releasably lock the latch subassembly 26 in its latched position. A tension spring 92 (FIGURE 5) connected between dog 86 and plate 70 holds the dog locked behind the shoulder. A pair of dog-release handles 94 are attached to shaft 88 on opposite sides of connecting bar 72 of the saddle so that the pawl can be unlocked from either side. About the only other thing that deserves specific mention in connection with the rack latching subassembly 26 is the opening 96 along the lower edge of saddleplate 70 to accommodate the passage of the T- shaped member 56.

The tray subassembly is most clearly revealed in FIGURES l-3, 6 and 7 to which reference will now be made even though several other figures show elements thereof as supporting structures for some of the functional subassemblies yet to be described. The tray itself comprises an elongate rectangular plate 98 bordered along both side margins by sideplates 100 that project downwardly from the underside thereof. Spaced along the length of each sideplate are stubshafts 102 upon which are journalled trunnions 104 that roll along the lower flange 106 of the track rails 42 as seen in FIGURE 6. In addition, a plurality of roller brackets 108 are fastened to the outside of each sideplate intermediate the trunnions journalling rollers 110 in position to engage the web 112 of the rails and keep the tray centered therebetween. The front end of the tray is enclosed by an oversized plate 114 having integrally-formed handles 116 projecting horizontally and laterally from the bottom edge thereof. These handles are used by the operator to guide the racking apparatus into the pigeonhole while suspended from the crane.

Now, when the load 14 is first attached underneath the tray preparatory to being loaded into the rack, the tray occupies the extended position relative to the track that has been shown in FIGURES 1 and 2. Because the tray is trunnion-mounted for rolling telescopic movement relative to the track it is, of course, necessary to lock them together in extended position until the time comes to move the load into the pigeonhole. Briefly, with reference to FIGURE 11, it will be seen that front saddleplate 68 is provided with a latch-pin track 118 that carries a latch-pin 120 for vertical reciprocal movement between an upper unlocked position and a lower locked position wherein the lower extremity thereof passes into an aperture 122 in the bedplate 98 of the tray. When latched, the tray and track occupy the extended position relative to oneanother that is revealed in FIGURES 1 and 2.

FIGURE 2 shows the track fastened to the rack and the load suspended from the tray ready to be moved into the pigeonhole. Before the load can be moved, however, latch-pin 120 must be released so that the tray can telescope into the track. It is also necessary to limit the telescopic movement of the tray so it will not run on out of the rear end of the track, a substantial proportion of the tray remaining in the track at all times. To prevent this, a stop 124 is provided on the underside of the tray near the head thereof that engages on abutment 126 provided on the underside of at least one of the rails as 6 shown in FIGURE 2. When stop 124 contacts abutment 126, part of the tray will be projecting beyond the rear end of the track and load 114 will be suspended above the set of load-supporting rack element 24 upon which it will eventually rest.

FIGURES 14 and 6-10, inclusive, each reveal certain details of the load-fastening subassembly and the loadreleasing subassembly that have been designated in a general way by

reference numerals

128 and 130, respectively. The latter subassemblies include a number of elements in common with one another, a fact which will become more apparent as the description proceeds.

The load 14 must be resting on blocks or in a rack such that the supporting cables 36 can be passed therebeneath. In the particular form shown, three such loadsupporting cables are used, one near the front end, a secloud in the middle and a third at the rear end. Each cable has a closed loop 132 formed on one end and a length of chain 34 fastened to the other end, the latter emerging from keyhole-shaped openings 134 (FIGURE 7) in faceplate 114 onto the front of the tray. Behind these keyholeshaped openings 134 are positioned a corresponding number of tubular guide tubes 136 fastened to the underside of bedplate 98. Each of these tubes is of a different shape and length as shown in FIGURE 3, the remote extremities thereof opening into cable-guide blocks 138 fastened to one of the sideplates of the tray. The guide tube 136a connected into the guideblock 138a located nearest the front end of the tray is provided with a reverse bend to increase the length thereof enough to accommodate a sufiicient length of cable to pass underneath the load. Guide tubes 136b connecting into the middle guide-block 138b and guide tube 1360 that emerges into rear guide-block 1380 require no such reverse bend as they accommodate enough cable and chain to pass easily under the load. All of the guide tubes and associated guideblocks are preferably located on one side of the tray as shown in FIGURE 3 to have the other side free for the load-release subassembly 130.

When the links of the chains 34 are allowed to drop down into the narrow neck of keyhole slot 134 as shown in FIGURE 7, the cables obviously become locked and cannot move in the guide tubes in either direction. Ordinarily, the cables are stored with the looped ends thereof adjacent the guideblocks 138. In fastening the load to the underside of the tray it becomes necessary to draw the cables from the guide tubes and blocks and pass them beneath the load to the points where they attach to the other side of the tray. It is desirable, therefore, to provide means for unlocking the cables so that they can be drawn freely through the tubes in either direction from a position beside the guideblocks; otherwise, another operator would be required to lift the chains up into the circular portion of the keyhole slots 134. Such a safety catch has been shown in FIGURE 7 and identified by numeral 38. It comprises a plate having a pair of transversely-spaced vertical slots 140 therein that slidably receive studs 141 located on the front of faceplate 114 beneath the keyhole-shaped openings 134. Ears 143 shown at the upper corners of the plate facilitate raising and lowering the latter between its full-line locked position and the dotted-line released position. In locked position, the plate uncovers the narrow necks of the keyhole openings allowing a chain link to drop down and lock therein; whereas, in unlocked position, it covers these narrow necks and raises the chains up into the circular portions thereof where said chains are free to slide back and forth.

Attached to the sideframe element 100 opposite the guideblocks 138 are the cable locks 142a, b and c. As revealed most clearly in FIGURE 8, each of these cable locks comprises a block having a longitudinal bore 144 therein within which latch pin 146 reciprocates. The front end of bore 144 is provided with an enlargement 148 terminating in a forwardly-facing shoulder 150 against which collar 152 fastened to the pin 146 abuts. An

apertured cap 154 loosely receiving the shank of pin 146 covers the open end of bore enlargement 148 and cooperates therewith to define a compartment for compression spring 156. The forwardmost extremity of pin 146 carries an ear 158 acessible to the operator through opening 160 in the bedplate 98 of the tray. There is a slot 162 extending from top to bottom of the latch pin block and intersecting bore 144 intermediate the ends thereof that receives the looped end 132 of the load-supporting cables from underneath. Apertures 164 in the bedplate 98 open above slot 162 so that the operator can see down into said slot from above and be able to guide the cable loop therein from underneath. With one hand, the operator reaches through opening 160 and pulls the latch pin forwardly by pulling upon ear 158 until the compression spring is fully compressed between pin collar 152 and cap 154. As this occurs, the rear end of the pin is retracted from within slot 162 and the operator can use his other hand to insert loop 132 into proper position. With the pin released through the loop in the end of the load-supporting cables, each of which is latched separately, the operator returns to the head of the tray and pulls upon all three chains 34 until all the slack is taken out of the cables, whereupon, safety catch 38 is dropped down into locked position shown in full lines in FIGURE 7 allowing the chain links to lock within the narrow necks of the keyshaped slots 134.

The load 14 is now in a position to be picked up and balanced. This is accomplished by means of saddle 66, the description of which will be completed by again referring to FIGURES l, 2, and 6 where it is most clearly revealed. Bar 72 has mounted thereon for longitudinal slidable movement a hanger fitting 166. The upper extremity of this hanger bar is slotted longitudinally at 168 and a pivot pin 170 extends transversely across said slot. Mounted on this pivot pin for pivotal movement is a connector 172 containing an opening 174 adapted to receive the hook 176 of the single-hook crane 12 (FIGURE 2) that is used to hoist the racking apparatus along with its load 14.

Now, paralleling bar 72 in spaced relation therebeneath is a jackscrew 178 journalled for rotation between

plates

68 and 70. The jackscrew projects through front endplate 68 and is provided with a crank 180 (FIGURE 2) that is used to rotate same.

Hanger block 166 projects beneath bar 72 and has a longitudinal threaded bore 182 that receives the jackscrew and cooperates therewith to enable the point from which the racking apparatus is suspended to move back and forth until it coincides with the balance point of the entire assembly including the load. In actual use, once the load is attached in place beneath the tray, the operator actuates the crane to lift the resulting assembly a few inches off of the blocks supporting the load and, if only one end lifts evidencing an imbalanced condition, he turns crank 180 to shift the pickup point forwardly or rearwardly as required until the system is in balance. If the load is positioned correctly on the underside of the tray, jackscrew 178 provides ample adjustment to balance the system. If, however, the rare situation should occur in which the jackscrew provides insufiicient adjustment to achieve the necessary balance, a small counterweight can be attached temporarily to the racking apparatus at the position required to shift the balance point back within the range of the saddle subassembly.

Once a balance condition has been achieved, the crane or hoist is employed to move the racking apparatus and load to a position in front of the particular pigeonhole in the rack within which the load is to be stored. The hoist then is actuated to move the rear end of the track subassembly rearwardly into the pigeonhole while the operator guides same from the front end by grasping handles 116. The track moves into position slightly underneath the load-supporting frame elements 24 that form the bottom of the pigeonhole directly above the one into which the load is being inserted. At this point in the operation, dog 86 is released from behind the shoulder 84 on pawl and operating handles 78 have been turned clockwise as viewed in FIGURE 2 to retract movable element 58 of the latch subassembly 26. Fixed latch element 50 is moved beneath rear load-supporting element 24 and then brought upwardly and forwardly again until it hooks over the top thereof from the rear. With element 50 so positioned, handles 78 are swung down into the position shown in FIGURE 2 so as to close element 58 onto the front of rack element 24 and complete the connection therebetween. As soon as this condition has been achieved, dog 86 drops into place behind shoulder 84 of pawl 80 and secures the latch subassembly in locked position. All this time, of course, tray subassembly 30 has been locked in the retracted position shown in FIGURES l and 2 by latch (FIGURE 11) so that the balance point cannot shift. Now, however, with the rear end of the track attached to the rack and the crane still secured to the saddle, it becomes possible to shift the center of gravity rearwardly without causing any damage. Accordingly, latch 120 is released and the tray along with the load suspended. from the underside thereof are run rearwardly along the rails of the track until stop 124 engages abutment'126 signifying that the load 14 is in prover position to be released onto elements 24 of the pigeonhole. The latter operation is accomplished by pulling on handle 32 of the loadrelease subassembly that will now be described in detail in connection with FIGURES l, 2, 3 and 6-10, inclusive.

Latch pinblocks 142 each contain a longitudinal bore 184, all of which are coaxially aligned with one another and which receive actuator rod 186 for longitudinal slidable movement. Fastened to this rod are latch pin retractors 188 that project laterally therefrom into position to receive the projecting end of the latch pins 146 behind the car 158 on the end thereof. The opening in these retractors through which the pins pass are slightly oversize to allow the pin to slide freely therein so that they can be retracted manually one-at-a-time for insertion of the cable loop. These same pins, on the other hand, must be retracted simultaneously when the load is dropped into the pigeonhole. Thus, by drawing rod 186 toward the front of the tray, retractors 188 will simultaneously engage ears 158 and pull the pins at the same time. Once the pins are drawn back out of slot 162, the looped ends 132 of the cables drop free and release the load. Compression springs 156 return the pins and actuator rod 186 to their original positions.

A collar 192 is fastened to the front end of rod 186 and this collar is pivotally attached to a link 194 that passes out onto the front of the tray through opening 196 in the faceplate 114. A block 198 having a cylindrical recess 200 therein is fastened to the faceplate beneath opening 196. Seated in this cylindrical recess for rotational movement is a disk 202 having a centrally located pin 204 projecting from the underside thereof (FIGURE 10) and an eccentric pin 206 on top. Link 194 pivotally connects to the eccentric pin and, upon rotation of the disk by means of handle 32 fastened to pin 204, said link moves from the full line position of FIGURE 10 into the dotted line position thereof causing rod 186 to retract.

Premature release of handle 32 would, of course, be quite serious as the load 14 would immediately drop free of the tray. Accordingly, safety latch 40 is provided on the faceplate 114 in position to engage link 194 and prevents rotational movement of disk 202. This safety latch comprsies a plate 208 having a pair of vertical slots 210 therein that receive headed pins 212 fastened to. the faceplate. These pins and slots cooperate to permit plate 208 to slide up and down alongside block 198 as clearly shownin FIGURE 9. The bottom edge of this plate is provided with an outturned lip 214 to facilitate raising and lowering same. The top edge of plate 208 has a portion 216 overhanging the block 198 and abutting link 194 when in safe position shown by full lines in FIG- URE 7. When the plate is raised into the dotted line unsafe position of FIGURE 7, however, the link 194 can move underneath the overhanging portion 216 and release the load.

Having :thus described the several improvements in the method and apparatus for racking steel with a single hook crane that constitutes the present invention, it will be apparent that the many worthwhile objectives for which they were developed have been realized. Although but a single specific embodiment of the apparatus has been illustrated and a single method for using same described, I realize that certain changes and modifications therein may well occur to those skilled in the art within the broad teaching hereof; hence, it is my intention that the scope of protection afforded hereby shall be limited only insofar as said limitations are expressly set forth in the appended claims.

I claim:

1. Apparatus for carrying elongated items to a rack having horizontally-disposed pigeonholes and unloading same therein which comprises: elongated track means adapted for insertion into the pigeonhole; rack-latch means mounted on the rear end of the track means for releasably fastening the latter in the top of the pigeonhole, said rack latch means including elements adapted to hook over both the front and rear surfaces of a transverse rack member and thereby prevent relative longitudinal movement therebetween in both directions; tray means mounted within the track means for telescopic movement; load-securing means carried by the tray means for releasably fastening a load to the underside thereof; load-release means connected to the load-securing means and operative upon actuation to drop the load into the pigeonhole when the track means is fastened to the rack and the tray means is telescoped into said track means; and, hanger means mounted on the front end of the track means for suspending the apparatus from a hoist, said hanger means including means for adjusting the suspension point horizontally to coincide with the balance point of the apparatus and load carried thereby.

2. The racking apparatus as set forth in claim 1 in which: the rack latch means includes a fixed latch element shaped to hook over the top of the transverse rack member from the rear, a movable latch element mounted for longitudinal movement relative to the fixed latch element between an open position disengaged from said transverse rack member and a closed position in engagement with the front of the latter so as to hold said fixed latch element in hooked position, and movable latch element actuating means accessible from the front end of the track means operative to shift the movable latch element between its open and closed positions.

3. The racking apparatus as set forth in claim 2 in which: the movable latch element actuating means comprises a plate mounted atop the track means for longitudinal reciprocating movement with the movable latch element carried on the rear end there-of, a rack mounted on the front end of the plate, a pinion mounted for rotation in meshed engagement with the rack, and crank means connected to the pinion for rotating same to effect reciprocating motion of the plate and movable latch element carried thereby.

4. The racking apparatus as set forth in claim 3 in which: the rack latch means includes a releasable stop means located to engage the movable latch element actuating means and lock same in closed position.

5. The method of racking elongate elements in a rack having horizontally-disposed pigeonholes therein by means of a tray telescopable within a track and a single-hook hoist which comprises the steps of releasably fastening the load to the underside of the tray while the track is extended, lifting the apparatus with the load suspended therefrom from a single suspension point closely approximating the balance thereof, inserting the rear end of the extended track into the pigeonhole, hooking the rearend of the track over both the front and rear surfaces of an interior overhead crossframe element of the rack at the top rear of the pigeonhole so as to eliminate all relative longitudinal movement therebetween While leaving the front of said track disconnected from the rack, telescoping the tray with the load suspended therefrom into the pigeonhole while supporting the front end with the hoist, and releasing the load from the tray.

References Cited UNITED STATES PATENTS 3,138,266 6/1964 Fahey et a1. 21416.4 3,146,016 8/1964 Daymon 294-81 X 3,257,001 6/1966 Postlewaite et a1. 2 14-1 ROBERT G. SHERIDAN, Primary Examiner. R. I. SPAR, Assistant Examiner.