US3257142A

US3257142A - Material handling system

Info

Publication number: US3257142A
Application number: US406604A
Authority: US
Inventors: Leonard D Barry
Original assignee: Individual
Current assignee: Individual
Priority date: 1960-03-25
Filing date: 1964-10-26
Publication date: 1966-06-21
Anticipated expiration: 1983-06-21

Description

June 2l, 1966 D. BARRY 3,257,142

MATERIAL HANDLING SYSTEM Original Filed March 25. 1960 5 Sheets-Sheet 1 1N VEN TOR.

inw/f@ June 21, 1966 n. BARRY MATERIAL HANDLING SYSTEM Original Filed March 25. 1960 5 Sheets-Sheet 2 INVENTOR.

June 2l, 1966 L. D. BARRY MATERIAL HANDLING SYSTEM Original Filed March 25. 1960 5 Sheets-Sheet 3 www June 2l, 1966 D. BARRY MATERIAL HANDLING SYSTEM Original Filed March 25, 1960 5 Sheets-Sheet. 4

IN VEN TOR.

S .mw

L. D. BARRY .MATERIAL HANDLING SYSTEM Original Filed March 25. 1960 June 2l, 1966 5 Sheets-Sheet 5 INVENTOR.

UnitedStates Patent O 5,257,142 MATERIAL HANDLING SYSTEM Leonard D. Barry, 19300 Pennington Drive, Detroit 21, Mich.

Original application Mar. 25, 1960, Ser. No. 17,658, now Patent No. 3,154,203, dated Oct. 27, 1964. Divided and this'application Oct. 26, 1964, Ser. No. 406,604

Claims. (Cl. 294-81) This invention relates to material handling methods and apparatus and more particularly to the handling, transportation, and storage of containers such as skid and gondola boxes, racks, and special containers.

This is a division of my application filed March 25, 1960, Serial No. 17,658, now Patent No. 3,154,203, this being a simplication applicable to industry and Warehousing o-r material handling generally.

An object of this invention is to provide an improved means for handling and storing racks, skid boxes, gondolas, shipping containers, etc. on overhead carriers. It is a further object to provide simple and inexpensive monorail carriers having means for engaging and holding containers when lifted thereto by a fork truck, portable stacker, or other elevating device preferably without requiring horiz-ontal movement of the load.

Fork trucks are frequently used to unload railway cars and trucks taking their loads considerable distances to deposit them in warehouses or work areas. It is an object of this invention to provide a material handling system in which the fork truck and its operator is better utiliz/ed.

In present overhead monorail carrier systems for transferring containers a hoist is provided on the carrier for picking up the container. the carrier and operat-es the hoist to stack and :remove ycontainers must look almost directly down on them, limiting the number of container carriers that can be loaded by the operator from the monorail cab. Automatic dispatching systems are available for monorail which elimi- .nates lthe necessity of the operator riding in the cab unless needed there to operate the hoist. It is therefore an object to provide a material handling system which combines the f-ork lift truck for loading and unloading with a train of inexpensive monorail carriers for transfer, resulting in faster and less expensive handling of transfer containers than presen-t methods.

It is an object to provide container carrying monorail trains f-or loading and unloading with a fork truck rather than have a hoist on each carrier. A train of these containers above a loading dock can be loaded by a fork truck unloading a string of freight cars, trucks, or other vehicles at the loading dock for example, thus reducing the distance that the fork truck is operated to deposit its load and thus maintaining clear dock area by suspending the load on the monorail without rst depositing it on the dock.

Some other and further objects are to provide means whereby the containers can be loaded onto and unloaded vfrom the carriers from the side of the monorail (fork truck at right angles to the monorail), which is most convenient for the fork truck operator and permits the containers t-o be stacked in a row directly under the monorail train, to provide a carrier which is inexpensive enough to :go into storage with the load and which can be pulled by a monorail tractor which can be dispatched by available vmeans without requiring the operator4 to ride with the train, to provide a carrier which can be adjusted easily to handle containers of various sizes and types, to provide a carrier train which conserves space, and to provide carriers having lcollapsible couplings to extend for train operation and to bunch the carriers together for storage Aand for bringing the containers close together for stacking The operator who rides with Patented June 2l, 1966 ICC in or rem-oval from a row directly under the monorail by means such as a fork truck or inexpensive portable stacker without requiring horizontal movement of the container lengthwise the monorail.

Other and further objects will be pointed out hereinafter or should be apparent from consideration of this invention as described with reference to the accompanying drawings wherein:

FIGURE 1 is a perspective view of a carrier in a monorail carrier train to which a fork truck is lifting a rack.

FIGURE 2 is a perspective view of a swivel nest.

FIGURE 3 is a broken sectional View on line 3-3 of FIGURE l.

FIGURE 4 is a .perspective view of an adjustable sill of a carrier. l

FIGURE 5 is an enlarged perspective View of the lock arrangement for the sill shown in FIGURE 4.

FIGURE 6 is a side elevation of a carrier for two containers.

FIGURES 7, 8, and 9 are respectively partial top, side, and end views of an adjustable hook yoke.

FIGURE 10 is a side elevation of a row of racks rand skid boxes in storage with atrainof the monorail carriers aligned directly above and a portable stacker for lowering and lifting the containers between the carriers and the r-ow, illustrating how little space is lost between containers.

FIGURE 11 is a view taken on line 11--11 of FIGURE 10.

FIGURE 12 is an oblique top view of an end portion of a carriers sill, showing the coupling latch.

FIGURE 13 is a side elevation of the preferred coupling and vportions of the end of the sills on coupled carriers.

FIGURE 14 is a view taken on line 14-14 of FIGURE 13 with coupling omitted and a portion of the yoke.

FIGURE 15 is a section taken on line 15--15 of FIG- URE 13 with coupling omitted and a portion of the yoke and wheel cut away.

FIGURES 16 and 17 are respectively the side and end elevations of a variation of the carrier holding a gondola.

FIGURES 18 and 19 are views of the hooks in respectively closed and open positions to show how the hooks on the containers operate the hooks on the carriers.

FIGURE 20 is a perspective View of the preferred hook for the rack, box, or tank type of container.

FIGURE 21 is a partial section taken on line 21-21 of FIGURE 17.

FIGUR-ES 22 and 23 are respectively side and end elevations of a variation of the carrier and container.

FIGURE 24 isa perspective view of a portion ofthe end of the container and supporting hook shown in FIG- URE 23.

FIGURES 25 and 26 are respectively top and side views of a variation of the hoo-k operating. mechanism shown in open position with a portion cut away for clarity.

FIGURE 27 .is a plan view of a typical installation at a warehouse or industry.

Referring to the drawings and in particular to FIG- URE 1, container carrier 10 ha's an overhead frame 11 secured to vtrucks or trolleys 12 .on track 14. Track 14 is preferably a` monorail track, but rope ways or crane type .Ways can be used in applications of this invention without departing from 'the Aintended scope thereof. Automatic latching and 4unlatching hooks 16 are pivotally secured to frame 11 for engaging and holding the container or rack 18 when lifted thereto by the elevating device here shown as fork lift truck 20.

Frame 11 preferably comprises a longitudinal sill 22 in the form of an I-beam and two hook yokes 24 each Atransverse Yto the sill at opposite ends thereof. Each yoke 24 supports two swinging hooks 16, one on each end. yEack yoke has two bars, channels 26, between which hooks 16 are each pivotally mounted preferably with a sleeve bearing to swing on pin 28, FIGURE 3, -which is positioned horizontal and parallel to the sill and secured from turning and endwise movement to a channel 26 by usual means such as tab 30 screwed to the channel and extending into a slot in the pin.

The corner posts of rack 1'8 each have a catch or hook 32 for engaging a hook 16 as the container is lifted. Hooks 16 are spaced in frame 11 to align with hooks 32. Hooks 16 are preferably arranged to swing back toward `the frame so that hooks 32 can be mounted facing each other on the sides of the posts facing the frame where they do not increase the overall dimensions of the rack and do not'interfere with the side loading of the rack. By having hooks 16 swing inward rather than endward the hooks can be opened even with racks abutting end to end.

Though hook yokes 24 can be integral or secured fast to sill 22 it is preferred to pivotally secure them to the sill at their mid points to permit the yoke to rock in a plane transverse to the sill so that each hook will take a share of the load according to the distribution of the load in the container and so that both hooks on the yoke will operate substantially together even with considerable vertical variation in the location of hooks 32 as would occur, for example when the fork truck tilts the container back in the forks as it lifts it to the hooks.

The -hook yokes are preferably of open triangular or trussed construction for strength andlight weight. Accordingly ties or angles 34 and 36 are run from channels '26 on respectively the inner and outer sides of the hook yoke'up to a pivot pin 38 above sill 22. The outer ties 34 of each yoke run in a plane transverse to the carrier while the inner ties 36 preferably diverge from the outer tie on the same side of the yoke as they run up to the vertex at pin 3'8, see FIGURE 3. The two inner truss angles are connected to the two outer angles at the vertex by pin 38 to make a rigid frame which can take end thrust from the container. If desired to reduce side sway, springs 40 can connect each side of the yoke to the sill.

Trolleys 12 can be secured either to the sill in a usual manner, FIGURE 6, or to the hook yoke. One arrangement for. securing trolleys 12 to the yoke is shown in FIGURES 3 wherein a thrust bearing nest 42, FIGURE 2, has inte-gral trunions 44 for mounting between the side plates 46 of trolley 12. An eye bolt 48 about pin 38 has its threaded rod extending up through a clearance hole 49 in the bearing nest. A spherical washer 50 and preferably a thrust Washer 52 are inserted in succession into the nest over the rod of the eye bolt 48, and then a slotted nut 54 is screwed on and secured by a pin. A sheet metal cover 56, FIGURE 3, snaps n over the pocket in the nes-t to keep dirt and Water out. The eye of bolt 48, which serves as a spacer between

angles

34 and 36, has a sleeve bearing 58 on which the hook frame swings. The ends of pin 38 extend through holes in either clip angles 60 or flats 61 to support the sill. Yokes 24 can be mounted anywhere along the sill on clips 60 according to the length of the container to be carried.

If the containers to be handled are of various lengths the clips can be adjustably secured to the flanges of the I-beam sill 22 as by bolts, or the sill can be made adjustable in length as shown in FIGURE 4, which shows the sill 22 composed of two channels 2.2` turned back to back With a U-shaped bracket 62 secured to'the end of each to gird the other so that the channels can be telescoped. A length of channe'l 22 is added to each end to form the I-beam section at the ends which are otherwise similar to the yoke shown in FIGURE 1. The Itwo channels are lockedin place by .any suitable means such as a toothed rack 63 secured along the bottom of the trough of one channel 22C and a dog 64 having teeth engaging the rack, the dog being secured to slide up and down on the bracket 62 secured to the other channel 22C. Dog 64 is secured by a bolt through slot 65 in the bracket to engage or disengage the rack and is preferably guided by pin 66 to keep it from turning.

More than one container can be carried on a carrier by vproviding a sill beam of sufficient length and adding the required number of hook yokes as shown in FIGURE 6.

The hook yokes can be adjustable for handling containers which have hooks spaced at various Widths apart. This adjustment is provided preferably with the rigid yoke frame retained as shown in FIGURES 7, 8, and 9 wherein channels 26 are turned to face each other to support vtwo riders 68 each of which support a hook 16 and a hook closing delay 70 to be described later herein. The riders are shown as two short channels 72 turned legs out and spaced by member 74 to slide between the troughs of channels 26. yI-Iook 16 is supported between channels 72 of the rider similarly as between channels 26, FIGURE 3. A headed pin 76 is dropped in a hole in the top of channel 72 to secure the hook in the desired horizontal position. The riders can be slid out the end of the yoke and turned end for end to hook hooks facing out.

Racks used for handling packages such as found in food warehouses are preferably provided with removable chain or link mail sides 78, FIGURE 1, to keep the packages from falling off, U-pockets at the tops and bottoms of the facing sides of the side posts support rods S0 on which the chain mail 78 is linked and secured.

The containers on a tr-ain of carriers must be spaced apart to turn corners, but where carriers are stored loaded or empty of where containers are stacked it is desirable to space the containers next `to each other to save space. Accordingly as a feature of this invention and with reference to FIGURES l, 3 4and 10-15 the end hook frames are placed on the ends of sill 22 with flats 61 extending down to cover the end of the I-beam sill 22 and extending outward from the flanges of the beam. Adjacent carriers 10, see FIGURES 1, 3, l0, and 13, are connected by `coupler bar `84 having ya vertical hole in each end. One end of coupling bar 84 is secured to swivel on tee bolt 86 swivel mounted between blocks 88 secured to the under side of the left hand end of the sill. The other end of bar 84 is pivotally secured to the bottom of the U-shaped bracket 90 of trolley 92 which has at least one wheel 93 or other support means for riding each lower flange of the sill beam 22 of the next carrier to the right. End plate 61 serves as a stop against which U-shaped bracket 90 bumps to keep trolley 92 from running off the end of the sill. A

coupling latch 94 (see FIGURES l2 and 13) has two triangular side plates 96 connected by `a shoulder rivet 98 to space the plates 96 to straddleI-beam 22 and is pivotally secured to the I-beam by pin 99 welde-d transversely across the top of beam 22 to position the latch to drop behind trolley 92 when at the left hand end of sill 22 to lock the coupling for operation of the carrier train T, FIGURE .10.

When the carriers are to be hunched at the end of their run, the coupling latches 94 are lifted by rope 100 yanchored at 102 to the sill of the last carrier in `the train and to drum 104 located either on the monorail tractor MT as shown in FIGURE 10 or on the first carrier if the tractor is used for other service. Rope is run over sheaves 106 which support it along the intermediate carriers of the train and through the eye of a link 108 welded on the swinging end of each coupling latch 94 for opening the latches between carriers. Drum 104 is welded on shaft 110 bearing mounted through plates 112 to the tractor or first carrier and turned by hand chain loop 114 draped over sprocket 116 which is keyed -to shaft 110. When chain 114 is pulled clockwise, FIGURE 10, reeling the rope 100 onto drum 104, latches 94 are lifted and the carriers are pulled into each other and hunched to form a string of carriers as shown in FIGURE 10. The racks 18 an-d boxes 18b can then be stacked in a substantially solid row without further horizontal movement lengthwise the carrier. They can be tiered as shown at the left of FIGURE by a fork lift truck or by the inexpensive portable stacker 118 which is shown removing a rack from a carrier.

Rubber bumpers 120, FIGURES 1, 3, 13, and 14 are provided to reduce the impact when the carriers are pulled together. It shouldV be evident that the containers can he .spaced against each other by slight modification if desired,

but leaving a space between the containers prevents scraping and catching during the lifting and lowering operations.

When the tension on chain 114 is released latches 94 drop by gravity, but the carrierson substantially level track remain hunched. The carrier train is opened out and recoupled for operation by running the tractor MT, FIGURE 10, to the right. This pulls the left hand end of sill 22 of the first carrier to the trolley 92 secured t-o the coupling bar 484. of the next carrier, etc. The trolleys 92 in passing to the left of latches 94 lift and latch them as the rope unreels from drum 104.

Referring to FIGURES 16-20, hooks 32 have a back plate 122 for strength and for mounting to a r-ack post, a top facer124 curved back and up from the face of the hooks tooth 126 for engaging and opening hooks 1.6, and a side plate 128 for keying racks 18 from slipping off hooks 16 or for mounting to a box, FIGURE 17. The side plate 128 extends beyond the front of tooth 126 to `guide upper hooks 16 past the tooth to engage thereunder.`

The side plate can be omitted where the hook is secured to the side of a box or structural member. With the side plate 128 made integral the hooks are cast or forged right and left hand.

Referring to FIGURES 16-19, hooks 16 have a long neck 130 which depends from the frame of the carrier to `an up and transversely outward turned tooth 132 which has a backward and downward sweeping front face for engaging with hooks 32. The side of hook 16 which engages with hook 32 or the container sweeps endward from the container to longitudinally align the container for coupling. With hooks 16 turned outward to engage with hooks 32 turned inward (facing each other) no space between racks and ya minimum of space between boxes is required for hooks and for the swinging of hooks. The head 124 of hook 116,- through which pin 28 runs, is long in the direction of the hole to take endwise torque resulting from acceleration and deceleration of the container. This design prevents endwise bumping of the containers into each other even when closely spaced on the hooks. The neck 130 of hook 16 extends from the head away from the side next to the container forming a chin 136 which offsets the hook to permit closer spacing ofthe containers.

A protrusion or preferably a wheel or roller 138 on the front of the neck of hook 16 is spaced to engage the top face of hook 32 to open hook 16 when the container is lifted by the fork truck a distance above hook engaging position. The hook 16 is then held open by a delayed return device 70 which is shown in FIGURES 18 and 19 as a special dashpot pivotally mounted between yoke 24 and lug 140 -on the back of hook 16. Dashpot 70 has free travel during the first portion of its stroke to engage hooks quickly but delays the return of the hook when opened until the lift operator can lower the containers below the hooks. A passage such as groove 142 on the inner face `of and lengthwise the cylinder of dashpot 70 near the'rod end thereof :allows air to pass freely between the head and rod ends during the first portion of the stroke of the dashpot. A check valve 144 connected to the head end of the dashpot exhausts air'as the 6 hook 16. The spring can be a compression spring in the head end of the cylinder of the dashpot. Only vertical movement of the lift is required to hook or remove the container. The fork truck can therefore load and unload my carrier from any angle.

Where -telescoping of the coupling is not desired, any suitable coupling can be provided on the ends of sill 22, which is shown as a square tubing in FIGURES 16 and 17 with a horizontal hook eye 146 secured to one end and a three-eye clevis 147 vertically secured to the other end, the pin of the clevis having a hook 148 at its bottom for pulling i-t down to open it and a compression spring 149 on and connected to the pin and resting on top of the lower eye of the clevis to close the pin.

Instead of running

angles

34 and 36 up to a pin 38 at the vertex of the hook frame they can be connected by a fiat piece or (as shown in

FIGURS

16, 17 and 21) by channel 150 which spaces and supports

angles

34 and 36 at the vertex. T he trolley 12 is connected to this hook yoke by eyebolt 151 Whose ey'e is pinned between the side plates of the trolley and whose rod extends down in succession through a hole in channel 150 at the top of the yoke, a spherical washer 152, and a nut 153 threaded on the eyebolt to support the yoke. The legs of channel 150 run transverse to sill 22, extend down, and are pivotally connected to the sill on an axis parallel thereto by clip angles 60.

Where the loaded carrier must travel a steep grade the carrier can be supported on a single trolley at the middle of beam 22, or as shown in FIGURES 22 and 23, the hook yoke can span the container to hook opposite ends.

' This carrier 10c has a hook yoke 24e comprising two dashpot is compressed but closes to hold the hook lifted channels 26C spaced apart between which hooks 16C are pivoted. Each channel 26e has the ends of a bent tie rod 168 welded thereto. The rods 160, which replace angles 34 and '36 for light construction, run up and over the load pin 162 of trolley 12 and are spaced apart and welded to pin 162 which turns on the side plates of trolley 12.

The container 18C has two hooks 32C symmetrical on the center line of each end near the top. Hooks 32e are fabricated of round rod 164 to form an inverted U flaring out from the end of the container along the top, as shown in FIGURES 23-23, to hook over the sides of hooks 16e to prevent the container from slipping sidewise off hooks 16C. Hooks 32C taper inward toward the top to guide hooks 16C into engage-ment therewith. Hooks 32C have a bar or flat 166 sloping down from the end of the container to the top of rod 164 so that rollers 138 engage this at to open hooks 16C when the container is lifted up from the carrier.

Instead of flat 166 a formed channel orchute 168, as shown in FIGURE 24, Ican guide hooks 16C into engagement. The tail of hook 16C comes to a point in the middle to increase the coupling range when used with chute 168.

So that the container can be removed conveniently from V hooks 16C closing delay again can be provided by dashpot 70 now pivotally secured between channels 26C and arm 170 integral with and extending up from hook 16C as shown on the right hand side of FIGURE 22, or a mechanical type delay can be provided such as that shown on the left side of FIGURE 22 wherein lever 172 carrying wheel 174 engages the top of the container 18e before it is lifted high enough to engage hooks 16a and 32e.

l Lever 172 has a linger 176 which extends out under a latch bar 178 pivotally secured to lever 178 on hook 16C in place of the dashpot 70. Latch bar 178 has a catch 180 which latches over linger 176 only when hook 16C is opened, i.e. when plate 166 pushes roller 138 out, swinging hook 16C up and pushing latch bar 178 to the right far enough to catch over finger 1 76. When bar 178 latches over finger 176 the container can be lowered with hook 16e remaining lifted until after bar 178 hits stop 182 and lever 172 drops finger 176 out from catch 180 when the container is below the hooking points of hooks 16e and 32C. Hook 16e then swings to vertical position under the force of gravity ready to hook the next container.

This hook latching arrangement is shown in the hook yoke assembly, FIGURES 25 and 2.6, with like items given the same reference characters as in the other figures. In this assembly the hooks 16C face outward and engage hooks 32 `which can be mounted to corner posts asin FIG- URE l or to a side of a box or other container as in FIG- URE 17 for example.

A typical application of the carrier is shown in FIG- URE 27 wherein D represents a loading dock; V a transportation vehicle such as a railway box car or a truck in -which containers 1S are shipped; M a monorail system having an overhead track parallel the dock on which a train of carriers T is spotted for loading and unloading; 20 the fork lift truck for unloading the transportation vehicle and for lifting the containers to engage the waiting carriers and for removing containers from the monorail and placing them aboard the transportation vehicle; MT the monorail tractor for pulling the train of carriers between the dock and warehouse or storage area SA which might be very remote from the dock and on a different elevation; 118 the portable stacker or fork truck which removes containers from the monorail and stacks them one above the other as shown in FIGURE or lifts them to load the carrier train without necessity of horizontally moving them.

In operation the fork truck operator on the dock runs fork truck 20 inside box car V, picks up a container on the forks, backs out under monorail M lifts the container engaging it on a waiting carrier, lowers the forks and drives under the carrier back into the car to pick up another container. In the meantime the carrier train is preferably indexed to align the next carrier adjacent the car door so when the fork truck operator backs out of car V the next empty carrier is waiting above for him to lift the container to it. Thus it should be evident that this system saves the fork truck operator from carrying each.

load into the warehouse, saves dock space as compared to a tractor trailer train, and enablesthe fork truck operator to transfer containers between the car andmonorail with a minimum of turning and movement.

When the car is unloaded or the carrier full it is taken to the warehouse or storage area SA and bunched over a storage-row where the portable stacker picks up the containers on'the carriers and thereby opens their hooks and then lowers them to stack them directly thereunder to await call for the item stored; at which time the stacker is used to load the container back on the carrier for delivery to shipping, processing, or manufacture where similar or other facilities can handle the container.

Stop 188 on the monorail, FIGURE 10, can be set to align the carrier train at the stacking area. The stop iS a dog pivotally secured to the upper flange of the monorail to swing down to engage a trolley 12. It can be worked by a pole or preferably by solenoid and maintains both raised and lowered positions by gravity. It is also useful in bunching a train of carriers with the aid of the tractor.

Having thus described a few of the many possible variations and applications of this invention it should be understood that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

I claim as my invention:

1. In combination a frame, a self-latching hook pivotally suspended from said frame to swing to engage a load below said frame, cam means for opening said hook wide when lowered on the load below hooking position, and means for delaying the return of said hook comprising, a latch pawl operated by the swinging movement of the hook, means engaging a load to be lifted thereby whenever said hook is near hooking position or below, and a tooth controlled by said last mentioned means to latch with said pawl to hold said hook open whenever said last mentioned means is moved to a point representing that the hook is cammed opened by the load enough to clear said load, and a stop on said frame engaged by said pawl for unlatching said pawl to c'lose said hook when said hook is above said load.

2. In combination: a hook for latching onto a load, a support t0 which said hook is pivotally secured to engage and disengage the load, means on said hook for engaging on the load to swing said hook open when the load is above engaging position with said hook, a follower lever arm pivotally secured to said support to ride the load, said lever arm having a finger extending laterally therefrom, a latch bar pivotally secured at an end to said hook at a point to have horizontal motion by the swinging movement of said hook and resting on said nger, said bar having means for said linger to latch with to hold the hook open when full open, and means on said support for supporting said bar when said arm is dropped to release said finger from said latch bar to release said hook to swing closed above load engaging position.

3. In combination, a hook having a pivot on which it swings to open and close on a load and cam means thereon for opening it when rested on the load, an arm extending up from said pivot, a latch pawl pivoted to said ar-m to be operated by the swinging movement of the hook, means for engaging the load to be lifted when said hook is near hooking position and below, and a tooth controlled by said last mentioned means for latching with and supporting said pawl when said hook is rested on the load, said pawl being supported on said tooth and remaining engaged until said hook is above load lifting position.

4. In combination; a frame, a cam-type latching hook pivotally secured to said frame to swing to open and close on a load and which swings wideopen when rested on the load, an arm integral on said hook and extending up from the pivot thereof, a bar having latching means intermediate the ends thereof, one end of said bar being pivoted to top of said arm to swing in a plane parallel with the hook, rider means supported on said frame for engaging the load to ride up and down thereon, said rider means latching with said bar when said hook is swung wide open as when spread apart by resting on a load, and means on said frame for supporting said bar to disengage said rider therefrom when said hook is above load engaging position.

5. In combination; a support member, two self latching hooks each facing oppositely and pivotally secured to said member at points spaced apart to swing oppositely to engage a load, each of said hooks having an integral upstanding arm above its pivot, a latching bar pivotally secured at one end to the top of each said arm so as to move the bar horizontally as the hook swings, a load rider having a nger which goes up and down as the load is engaged and disengaged, both of said bars resting on said nger to latch therewith when each said hook is swung wide open, and means on said frame for supporting said bar when said rider is lowered to release said rider from the latches of said bars to return the open hooks to engaging position when lifted above the load.

References Cited by the Examiner UNITED STATES PATENTS 1,905,427 4/1933 Ackerman 294-110 X 2,403,346 7/1946 Deiters 294-110 X 2,547,502 4/1951 4Smith 294-67 FOREIGN PATENTS 216,637 5/ 1924 Great Britain.

GERALD M. FORLENZA, Primary Examiner.

SAMUEL F. COLEMAN, Examiner.

G. F. ABRAHAM, Assistant Examiner.

Claims

1. IN COMBINATION A FRAME, A SELF-LATCHING HOOK PIVOTALLY SUSPENDED FROM SAID FRAME TO SWING TO ENGAGE A LOAD BELOW SAID FRAME, CAM MEANS FOR OPENING SAID HOOK WIDE WHEN LOWERED ON THE LOAD BELOW HOOKING POSITION, AND MEANS FOR DELAYING THE RETURN OF SAID HOOK COMPRISING, A LATCH PAWL OPERATED BY TEH SWINGING MOVEMENT OF THE HOOK, MEANS ENGAGING A LOAD TO BE LIFTED THEREBY WHENEVER SAID HOOK IS NEAR HOOKING POSITION OR BELOW, AND A TOOTH CONTROLLED BY SAID LAST MENTIONED MEANS TO LATCH WITH SAID PAWL TO HOLD SAID HOOK OPEN WHENEVER SAID LAST MENTIONED MEANS IS MOVED TO A POINT REPRESENTING THAT THE HOOK IS CAMMED OPENED BY THE LOAD ENOUGH TO CLEAR SAID LOAD, AND A STOP ON SAID FRAME ENGAGED BY SAID PAWL FOR UNLATCHING SAID PAWL TO CLOSE SAID HOOK WHEN SAID HOOK IS ABOVE SAID LOAD.