US2599855A - Load-handling attachment for lift trucks - Google Patents

Description

June 10, 1952 w. lw. MlcHAUx, JR

June 10, 1952 w. w. MlcHAux, JR

LOAD-HANDLING ATTACHMENT FOR LIFT TRUCKS Filed April 17, 1950 2 SHEETS-SHEET 2 IlI Patented June 10, 1952 y OFFICE n LOAD-HANDLING ATTACHMENT Fon LIFT TRUCKS william W. Michaux, Jr., Richmond, va. Apueation April 17, 195o, serial No. 156,340

Y l Claims. 1

In the handling of large heavy and bulky articles of generally uniform size and shape such as hogsheads of tobacco. or rolls of newsprint, it is customary to use so-called lift trucks which are power-operated trucks incorporating hoisting or lifting mechanism. One form of such a lift truck consists of a wheel-supported frame having normally vertical guide means on which a slide including normally horizontal article-supporting arms or forks is mounted. The power means, usually an internal combustion engine carried by the frame, can be connected to elevate the slide along the aforesaid guide means irom one position in which' the article-supporting forks are closely adjacent the fIoor,-to another position in which these forks are elevated severalr feet above the floor so that articles of the kind described can be conveniently elevated for transportation from one location to another, for stacking, or other purposes. In the power-operated handling equipment just described, the vertical guide means previously mentioned'is mounted upon the frame for pivotal movement or tilting about a horizontal axis close to the floor and normal to the vertical. guide surfaces andlto the' aforesaid forks. In using such equipment, for instance, to elevate hogsheads ofv tobacco from one level to another, asin stacking. the-truck is propelled forwardly until the `supporting forks are thrust beneath the' hogshead.` The hoisting l mechanism is then clutched vin to elevate the forks and, substantially simultaneously, to pivot the guide means aboutits horizontal pivotaxis whereby the free ends of the forks are tiltedupwardly and gravity acts to hold the. hogshead from rolling oi the forks. After the hogshead has been elevated to the desired heightand properly positioned, the guide means isrestored' to the vertical so that the hogshead either rolls ofi the now horizontal-forks' by itself or bythe application of a small force applied manually.

In the practice just described, difficulty is frequently encountered in getting the forks fully beneath the hogshead. That is, the hogshead, unless prevented from se doing, may start to roll away from the truck 'before the forks canbe tilted sufficiently to hold itin position thereon. Furthermore the tilting of the guide means or columns together with their forks, is a,time

consuming operation amountingto a large loss in the course of handling hundreds or thousands of articles.-

Y It is therefore the Iprincipal object of my invention to provide adevice in the natureof an attachment for hoisting andhandling equipment of the type, described, particularly lift trucks,

wherein the objectionsand drawbacks enumerated are overcome and obviated.

More particularly, it is the purpose of my nvention. to provide an attachment which as the forks are thrust beneath an object to be moved, automatically operates in response to engagement with the object to positively secure the object on the forks and to prevent it from rolling or sliding thereof'f.

Another object is the provision of an attachment as described which, by securing the hogshead or other object upon the supporting forks, makesy it unnecessary to tilt the guide columns or mast upon whichthe load carriage is mounted for translation. Indeed, where a lift truck is built solely for rhandling of articles or objects of the type described, the tilting mechanism may be eliminated with a corresponding substantialr reduction in initial cost of the equipment.

A still further object is the provision of an attachment as described which is relatively simple and inexpensive to construct, positive in operation, and which may be easily applied and attached toexisting lift trucks as Well as embodied in trucks to be built.

yAnother object is toprovide a mechanism as described which is positive and. automatic in operation in securing in position upon the forks, an object or article being transported and one whichis easilyV and simply released when the object or article isto be deposited.

Yet another object is to provide al combined lift truck and article-securing attachment thereforewhich permits the elimination of complicated l and expensive parts of the truck while retaining all the functionsof prior art lift trucks.

Other objects and advantages will be apparent to those skilled in the art after a study of the followingdetailed description in connection with the accompanying drawings.

In the drawings:

Figure 1 is a side elevation showing, a lift truck equipped withv my invention and, in dotted lines, the position of the partsjwhen the truck has been operated to raise a hogshead of tobacco to'substantially maximum elevation. Y

Figure 2 is a plan view to an enlargedscale of the lift, portion of a truckequipped with the invention, the tine or article-engagingl party being shown-in; forward or unlocked position.

Figure 3. is a detail sectional View on line 3 3, Figurer 2, and tolan enlarged scala-of the rearwardv portion of the support bar. and locking slide, theparts being in a position`of the tine corresponding; to Figure Y2.

Y with the axis of wheels 3.

but showing the slide bar in position locking the tine in position to secure an article on the lift forks.

Figure 5 is a view corresponding to Figure 4 but showing the end of the locking slide in raised position to unlock the same.

Figure 6 is a side elevation of the support arm and tine, the latter being in locked position, and

Figure 7 is a cross section on the linel--l of Figure 3.

Referring in detail to the drawing, and particularly to Figure 1, the numeral I identies generally a well-known type of power operated lift truck comprising a body 2 supported for rolling movement by two-power-driven wheels 3 and a steering wheel 4. The body has a platform Elon which the operator stands to operate steering wheel 6 and control levers, one of which is indicated at 1. The lift guide or frame comprises generally a pair of spaced generally vertical beams of masts rigidly connected in spaced parallel'relation. One of these beams is shown at 8.

` This frame is pivoted to body for angular movement about a horizontal axis generally coincident A power-operated lever 9 is pivoted at one end to the lift frame and is retractible by power-operated mechanism, not shown, lto pivot the frame and load-supporting slide |0 about the aforesaid axis from the position shown upon Figure 1 to a position in which the frame 8 is tilted rearwardly a few degrees.

The slide I0 has interconnected elongated slide members, each guided for vertical translation by the .channels of frame 8. Such translation is effected by well-known mechanism including chains A pair of lift forks I2 and I3 (see Figures l and 2), are fixed to the lower portion of slide I0 in parallel spaced relation to the oor when the slide is in lowermost position. A prime mover, usually an internal combustion engine, is mounted in body 2 and can be connected by suitable control levers such as 'I to propel the truck, elevate the slide I0 and tilt the frame 8.

The mechanism described in the preceding paragraphs is well known and, apart from the combination,V forms no part of my invention, now to be described. The load supporting slide ID has a carriage guard Illa rigidly connected with the slide. To the uppermost horizontal member of this guard, I Vattach in spaced relation therealong, a pair of brackets I4 and I5, Figure 2, in which a shaft I6 is journaled in horizontal position. A forwardly-extending arm I1 is fixed at one end upon shaft I6 adjacent bracket I4. See Figures 3 and 4. A brace bar I8 is fixed at one end to arm and at its other end to shaft I6 adjacent bracket |-5, to impart rigidity to the arm. As shown upon Figure 7, the arm may lbe rectangular in cross section. By this construction, the arm is mounted for swinging in a vertical plane about the axis of shaft I6, from the generally horizontal position shown at Figure 1,

to a vertical position. A bracket 20, is fixed to a portion of the .carriage guard IUa, to limit downward pivotal movement of arm to the i horizontal position shown.

A tine 2| of the general shape shown in Figure 6, has a longitudinal slot 22 formed in its central portion of a width sufficient .to accommodate the end of arm with a smooth fit. A .pin 23 passes through the tine and arm to pivotally connect them whereby the tine may pivot from the loading position of Figure 1, to the locking position of FigureY 6. Clockwise-movement from the loading position is limited by en- L.

gagement of the corner 22a of the slot with the top surface of arm I1. This limit position is about as shown in Figure 1 in solid lines.

A channel locking bar 24 has a sliding fit over the arm and extends therealong from a point somewhat rearwardly of tine 2 I, as shown in Figure 1, to a point a little forwardly of shaft I6. The forward end of the locking bar has a strap portion 24a extending downwardly and about the arm I`| whereby this end of the bar is limited substantially to sliding movement along the arm. This end of the bar also has an upwardly offset portion A2,417. A pair of links 25 and 25 (see -Figures 2 and 6) are connected by a common pivot pin 2l with the forward or load-engaging end of tine 2| while another common pivot pin 28 connects these links with portion 24h of bar 24. By this construction, the locking bar is in the forward position of Figure 1 when the tine extends forwardly and in the rearward position of Figure 6 when the tine extends rearwardly in locked position.

The rearward end of bar 24 has a strap portion 24o extending downwardly and about arm I1. As seen in Figure 7, there is a substantial clearance between the strap and arm so that the bar, at this end, may be moved upwardly a short distance. This end of channel or bar 24 has a raised or upwardly inclined cam portion 24d and an aperture 29 adapted to drop over pawl I9 :fixed with arm I'| as the bar moves into locked position. Thus, as the locking bar slides rearwardly on arm in response to swinging of tine 2| from forward position to locking position, cam portion 24d rides up on pawl I9. and, in the final locking position of tine 2|, bar 24 drops over pawl I9 to hold positively or lock the tine in final position. A pair of links 30, one of which is sho-wn at Figures 3, 4 and 5, has spaced apertures. Shaft I6 Y passes through the lowermost of these apertures and each link is rigidly secured to the shaft as by welding or set screws.V A release rod 3| is journaled in the second or upper apertures of links 30 and is xed against axialv movement as by collars. At its portion in alignment with cam portion 24d, rod 3| has a release lug 32 fixed thereto so that when the parts are in the. locking position of Figure 4, cam portion24d lies directly over lug 32. Then when shaft 3| is pivoted clockwise to the position of Figure 5, lug 32 lifts the adjacent end of locking bar 24 until itv clears latch I9 to thereby free the tine formovement to forward or article-releasing position. An operating lever 33 is fixed to the left end of rod 3 I.

For operating lever 33 clockwise to release the bar 24-from pawl I9 I have provided a vertical tube 34 positioned at the right of the operator when he is in positionupon'platforr'n 5.' This tube has a pulley 35 fixed at its top.' Aweight 42 slides within the tube and is connected by a cord or rope 36 with lever 33.' As 'shown'at Figure 1, this cord has one end attachedV to 'lever`33 and then passes downwardly about-aV pulley Y3'! attached to a bracket carried slideIiL then upwardy over and about a pulley V38 'carried Vat the top of the frame o r mast l8 andthericein a horizontal -pass to pulley 35. Thisrhoriz'ontalpass therefore at all 'times extends 'diagonally across and in front of the operatorfaiid is always'in the same convenient position. As the -load-supp'orting slide I0 is elevated by chainsY |'I"urile1f' drive from the motor of the truck, the weight within tube a4 slides therein and acts tokeep the cora Y 36 taut.l A- second pulley BBQ-is'munted at the Vpulleycti Asthe'slide-is elevated and pulley 31 vmoves above pulley 38,- the cord 36 then extends 4from vthe horizontal pass underi and upwardly about pulley 38a, asindicated in dotted lines upon Figurel. f Y

For the purpose of resiliently and yieldingly holding the rearward end of bar24 upon-arm- I'I, a rod'39 is fixed at oneend to-shaft 3I. The other end of Ithis shaft is bent at 90 and has a; roller 4l)"jou'rnaled thereon in position to contact the upper surface of vbar 24. A tension coil spring 4I is. secured at oneend tov rod 39 and atthe other end to the adjacent side offarfn I1 and thus acts to: urge' the roller'down upon bar 24'- and to yieldinglyV lfi'oldv the bar uponarm I'I unless and until released by a pull on-cord 36. Spring'III also'l acts to hold4 lever 33 in the inactive position shown upon Figure l.

In operation, the Atruck with parts as shown in Figure l',` is propelled toward a hogsh-ead H of tobacco.` As the grippingend of tine 2| contacts the upper portion of the hogshead, the tine is pivoted rearwardly while at the same time the arm I'I, bar 24 and parts attached' thereto, may pivot upwardly slightly about thev axis of shaft I 6. The parts are so proportioned and dimensioned that forks I2 and I3 are fully positioned beneath the hogshead shortly after the instant that Ybar 24 drops into locking position over pawl I9. vThe parts arethen substantially as shown in the dotted line position of Figure 1 whereby the hogshead is securely held against rolling off the supporting forks. The lift slide may then be operated to'raise the hogsheadto the desired or necessary height. When it is desired to release the hogshead, the operator merely reaches up and pulls upon the horizontalv pass of cord 36 to pivot lug 32 andthereby effect release'of bar 24 in the manner obvious from inspection of Figure 5. Of course, the invention is equally useful when the truck is being used to remove hogsheads from a stack thereof to the floor.

While, for the purpose of complying with the patent statutes, I have described the device in connection with the handling of hogsheads of tobacco, it will be understood that, as already intimated, the invention is not limited to such use but can be readily adapted for handling rolls of newsprint, barrels, kegs, drums and other articles of regular or irregular shape. Hence the foregoing description is to be taken in an illustrative rather than a limiting sense; and it is my desire and intention to reserve all substitutions and modifications falling within `the scope of the subjoined claims.

In the claims, the terms load-release and load securing positions as referred to the tine 2| means the respective positions thereof in which the tine releases and secures a load upon the forks I2 and I3.

Where articles are being handled which might be damaged by the use of a pointed tine as shown, such for example, as rolls of newsprint, a tine equipped With a tip of rubber or other frictional material will be substituted.

Having now fully disclosed th-e invention, what I claim and desire to secure by Letters Patent is:

l. The combination with the vertically movable slide and load-lifting fork of a lift truck, of a normally horizontal arm carried by said slide above said fork and having a latch at one end, a tine pivoted to said arm at the other end thereof, a bar slidable on said arm, a link pivoted at its ends to said tine and bar, respectively, whereby said bar is translated along said arm in `response tovp'ivoting. of said tine, andfmeansion l'said arm releasably engaging said latchwh'en said ltine extends downwardly and rearwardlytowardsaid latch.

2. -In combination,- a vertically movable sli'd'e of ay lift truck, a load-lifting fork carried said slide and extending horizontally therefrom ka normally horizontal arm pivoted on said slide labove and over said fork, said arm having a latchadjacent one end, a tinep'ivoted-vto said-arm at the other end thereof, a barv carriedby sai'd arm, means mounting the 'endof said bar' adjacent said tine for slidingrr only on and alongl said arm, a link connecting said end ofy the bar and tine,

'whereby said .bar-slides uponV saidl r'e'- sponse to pivotingy offsaid tine,- m'eans mounting the other' end of said bar forslidi'ng and/or lat'- eral movement relatively to nsai-d arm, and means carried by said other end-of the" bar' for cooperation with' said latchto automatically lock said bar inV position corresponding to a load-securing position of saidtinerelatively to said-arm.'A

3. In combination, a vertically movable' power- .operated slide for a liftl truck, aglad mtmgfrk carried by said slide, anarm above and extendingI oversaid forkv in generally parallel, vertically-spaced relation therewith, a tine connected with said arm at oneend thereof for movement from a first position releasi'ng'a'. load on'said fork to a second position securing a.I load thereon, bar means carried by saidarm andconnected with said' tine at one end thereof for movement from first to second position relatively to saidarm, by

landin response-to corresponding movement of said tine, and latch means operable automatically as said bar means moves intosecond position to positively lock said'ba'rvmeans and tine in their second positions.

4. In a device to secure a load upon the forks of a lift truck, a shaft, an arm fixed at one end to said shaft at right angles thereto, a load-engaging tine pivoted on said arm at the other end thereof, a bar carried by said arm and substantially coextensive therewith, means mounting the end of said bar adjacent said tine for translation only on and along said arm, link means pivotally connected at one end with said tine and at its other end with the adjacent end of said bar, whereby said bar is slid along said arm from first to second positions in response to movement of said tine on said arm from load-releasing to loadsecuring positions, respectively, latch means between said arm and bar adjacent said shaft and operable automatically in response to movement of said bar to second position to lock the same in second position, bracket means fixed to said shaft, a rod journaled in said bracket means parallel with said shaft, and latch release means carried by said rod and operated by pivotal movement thereof to release said latch means.

5. A device as recited in claim 4, said bar being adapted for lateral movement relatively to said arm at its end adjacent the shaft to release said latch means, and a lug carried by said rod to engage and so laterally move said bar and release said latch in response to pivotal movement of said rod.

6. A device as recited in claim 5, a lever fixed to said rod and having one end extending over said bar, and spring means urging said lever into contact with said bar to hold the same in engagement with said arm.

7. For use in a lift truck having a vertically movable slide and a normally horizontal elongated arm pivoted at its inner end to said slide on an. axis normal thereto, a tine pivoted to said arm atthe outer end thereof, for pivotal movement from a first position extending forwardly and downwardly with respect to said arm, to a second position extending rearwardly and downwardly with respect to said arm, a locking bar Ypivoted at its outer end to said tine and slidable along said arm in response to movement of said tine between rst and second positions, detent means carried by the inner ends of said arm and bar and automatically operable in response to movement of said tine into second position to lock the same in said second position.

8. In a device of the type described, a vertically movable slide of a lift truck having load-supporting fork projecting therefrom, an arm pivoted at one end on said slide above said fork in normally parallel relation therewith, tine means carried by said arm at the other end thereof above said fork and pivotable thereon from a load-releasing d to a vload-securing position. a bar slidable on and valong said arm, link means connecting one end of said bar with said tine for sliding said bar from a rst to a second Vlimiting position in response to pivotal movement of said tine from load-releasing to load-securing position, a latch xed on said arm adjacent the pivot thereof, and

means carried by said bar to engage said latch Vand releasable lock said bar relatively to said arm as the bar moves into second position.

9. The combination with a lift truck having a slide guided for vertical movement and a pair of normally horizontal load-supporting forks xed to said slide, of an arm carried by said slide in vertically spaced parallel relation with, and above said forks, aV tine pivoted to the outer end of said arm and pivotable thereon from a forward and downward release position to a rearward and downward, article-retainingposition, a lock bar pivoted at one end to said tine and longitudinally slidable on and along said arm, and means operable automatically to lock said bar to said arm in response to pivotal movement of said tine to release position.

10. In combination with a hoisting and handling mechanism having a vertical slide and article-supporting means guided for'translation on and along said slide, an arm pivoted on said slide above and in spaced generally parallel relation with the article-supporting means, articleengaging means carriedV by said arm at the end thereof and movable in response to engagement with an article as it moves onto said article-supporting means, from article-release position to article-locking position, means automatically operable to releasably lock said article-engaging means vin locking position, and manually operable means to release said locking means.

WILLIAM W. MICHAUX, JR.k

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS

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