US2274164A - Lift truck - Google Patents

Description

Feb. 24, 1942. G, QUAYLE 2,274,164

H LIFT TRUCK l' Filed Nov. 4, 1959 4 sheet's-shee't 1 M jim,

INVENTOR 5 @UF6-004,05

' ATTORNEY` v Feb. 24, 1 942.

' FiledNov. 4, 1939 4 sheets-sheet `2 'ATTORNEY G. QUAYLE LIFT TRUCK Feb. 24, 1942.

Filed Nov. 4, 1959 4 sheets-shet 3 INVENTOR faefagyzf BY ATTO FIN EY Feb. 24, I1942.

G. QUAYLE LIFT TRUCK Filed Nov. 4, 1939 4 Sheets--Sheefl 4 INVENTOR 650665 7am/f ATTORNEY Patented- Feb.l 24. 1942' "Lnrifriwcir Y George Quayle, Philadelphia, Pa., assignorto The 1 Yale Towne Manufacturing Company, Stamford, conmgacorporation of Connecticut 4, i939, semi-No. 302,891

Application NovemberV sciaiins.l (Cien-2)" This invention relates toa lifting-truck of the type inl which an' elevating platform islifted by an appropriate lifting mechanism. More particularly, this invention relates toa lifting-truck ofthe typedisclosed in the U; S. Stuebing PatentV No. 1,785,368, owned yby The Yale 8x TowneMan-v ufacturing Company, the .owner of this application.y Y Y Even more particularly, this inventionA relates toa lifting truck of the type in which the lifting platform is adapted to enter between the upper and lower floors. of a reversible skid platform or Y pallet, with l,the feature that when the platform `is elevated, the pallet :islifted pif the ground or floor on which it rests. .f

v'I'he truck which -I have conceived preferably, forms a unit separate 'from the lifting n and reduced Y to practice utilizes an elevating platform which.

tion described hereinafter may be stood, and that the relation of my contribution to the prior art maybe better appreciated. I` shall now describethe preferred specific form-of my contribution to the art, it being understood,'of

course, that my contribution may be embodied in many specific forms by those skilled in the art ,without vdeparting from the spirit and'substance,`

' thereof.

In the drawings, Fig. 1 is yan elevation of my ftruckywith certain parts shown infsection to similar to Fig. lwith the parts in the same re'-V lation. showing the lifting platform of the truck head' through which the platformislifted. There lare means whereby the platform` isadapted. for

lifting movement `relatively to the lifting head lifting head. `Since the lifting head is at the front end of the truck. the said `means holdingy the elevating platform in assembled relation tothe. lifting head are at the frontend of the elevating platform, and I extend means from'the said front end connecting meansto the rear of the truck for operating means at the rear end ofthe plat- Y formwherebyto simultaneously lift the front andY rear endsof the platform.

.More particularly, in my-inventicn I employ 'a lifting head, which may be ofany particular form having lifting mechanism, but which lis preferably the type shown inthe Stuebing Patent view similar to Fig. v2, showing the elevating 'platbetter illustrate their` operation. Fig. 2 is a ,view

located'. between the upper and lower iloors of'a reversible skid platform or pallet.` Fig. 3 is -a form in elevated position. Fig. 4 is a view-looking downwardly on Figi: .1 with, the operating 'partsofthe truck platformexposed by the elimination of covering plates. Figs. 5 and 6 are vwhile maintainedein assembled relation'to that respectively lsections along linesl 5 5 .and H 1 of Fig. l. Flg.7 isaperspective viewV of thefront `end of the elevating platform and the parts connecting that end of the platform tothe lifting head, taken somewhat along the lines 5 5 of Fig. 1.

Referring now more particularly tothe draw-l ings, the lifting head of my vtruck'is designated by reference numeral I0, and maybe considered l as, practically identical with the lifting head of i `the truck lshown in the siuebing Patent. No.

supra.v I providean elevatingplatform pivoted,f l preferably through links. to thelifting head, wlth the feature 'that the platform. is movablebythe lifting -means relatively' to lthe lifting head. flilat- "o urally, the liftingl means maylbe means acting toY separate Vthe lifting platform and lifting head,y and thereby lifting theplatform. v l

Through the provision of linkage means which are actuated when the front end of the .platformV is iified relatively to the iifting head, .wheels an;

the rear 'of the .platform are simultaneously'- moved relativelyto the platform andserve to.

lift the platform.V Preferably, theserear wheels are sov mounted that theyfare capable of moving between the boards of av reversible .pa1lei'., soineA what in themanner disclosed in myaliplication for 'patent SerialNo 184.918, nled January ifi, l' 19'38patented May 20, '1941' as Patent 2,242,432. v I have thus. described-generally my contribu- 1,'185,368. ySince the construction of the'lifting.

vhead of the platformof my truck isV not in itself a .part of my contribution to theart, I shall not in this specification venture'into muchI detail in describing it, since those desiringto ascertain its j construction v may refer to the said Stuebing patent.`

- However, itvmay wenn, 'mainte t1-the lifting head comprises supporting `wheelsl l'. `-1 1d, a steering and lifting handle l2, downward ingmovement of which actualice a strut Il, which in turn vmoves a lever I4; on"zwhfich is mounted a -liftingjpawll il ooclierittixig with a lifting: ratchet' il. witliftlielifting ratchetullare lifting links Il, ,Ar-holding'pawl Il 'is` adapted, Q hold the lifting-ratchet yII in any positionto whichlit 1 8 rotated-,by .the mll! pawl' I5. A controlling It is manipulated by a- `foot treadle 2lto1"control thevrel'ea'se of the lifting pawi II and the holdlnapwl Il relatively toineiiiting ratchet-is. v In one position-.of the t'readle 20 shown in tion tothe art in order that the specific construc- 55 FIB'. V1, both the lifting and holding pawls are in contact with the lifting ratchet so that a series of'downward swinging movements of the lifting handle I2 will rotate the ratchet I6 to rotate the lifting links I9 from their initial position of Figs.

land 2 to their position of Fig. 3. Movement of the treadle 29 will, through the cam I8, move Yboth the lifting and holding pawls out of contact with the ratchet I6, and allow the lifting links I9 to move from their position of Fig. 3 to their position of VFig. 1 incidental to the lowering movement of the elevating platform. So far as my contribution is concerned, it is merely neces-Y sary "to consider that the elevating platform is lifted as the lifting links I9 are rotated clockwise, and that when the links I9 are released for counterclockwise movement, the elevating platform willbe moved to`- a lowered. position, as will be described presently.

The elevating platform of my truck is l shaped, as best shown in Fig. 4, and comprises a pair. of identical platform legs 2| and a saddle 22.` It will of course be appreciated that for legs 2|, and the said saddle extends/vertically, asY

bestillustrated in Figs. 5 and '7, to a point 23.Y -At each side of t/he saddle, somewhat below the portion 23 thereof, there are secured a pair of plates 24. EachV pair of plates 24 supports av pivot shaft 25 on which is pivoted a link 26. The other end of each link 26 is pivoted at' points 21 to-the liftinghead I0. g Ateach 4side ofrv the Vlower end ofthe platform saddle, thereis secured a plate 28 `which supportsA vone endof a shaft 29.? Each of theshafts 29 extends fromiplate 28 through a side bar 30 of onev of the platform legs, through plates 3| and'32 of the saddle, and then through the other side bar 33 ofA the particular Vplatform leg. Mounted on each of the shafts 29 is a pair of lifting struts 34 which are secured by a pivot shaft 35 to each one of the lifting links I9 of the lifting head. It is therefore readily seen, especiall:1 from Figs. 1 and 1, that a clockwise rotation of the lifting links |9'will 'impart movement to the' lifting struts 34'to lift the saddle 422 of the elevating platform throughshafts 29. I

Mounted on each of the shafts 29 between plates 3| and 32 of the saddle is a peculiarly shaped front end connecting link 36. Each front end connecting link comprises av lever 31 welded as at 38 to a sleeve 39 fitting about the shaft 29. Welded to the sleeve 39, or otherwise suitably secured thereto, are aJ pair of ears 40 which in turnare secured by a pivot shaft 4| to a rod 43 through a suitable clevis 44. In order to allow' for ready adjustment of the rod 43, it may b'e in threaded relation to the clevis 44, as will be appreciated by those skilled in the art. Each lever 31 issecured vat its front end through a pivot "shaft 45 tothe lifting head. I|I.` It will now be appreciated thatV when the Ysaddle 22 moves vertically from the position of Figs. 1 and 2 to the position ofFig. 3, the upper and lower connecting links 26'and 36 will swing from their positions of Figs. l and 2 to their position of Y Fig. 3, and that this will effect movement of the rods '43 to the rightilookingat Figs. 1, 2 and 3). This movement of rods 43 is'utilized for lifting the rear end of the elevating platform simultane-` ously with the front end thereof. For this purpose, each of the lifting legs 2| has pivoted thereto at 46 a rear lifting link 41, each carrying wheels 48. of course, secured in adjustable relation to a clevis 49 which is pivoteds at 5B to each of the links `41 to impart movement thereto. As the rods 43 move to the right from the position of Figs. l and 2 to the position of Fig. 3, the links 41 are rotated counterclockwise, and the wheels 48 are moved into the positions shown in Fig. 3,

thereby elevating the platform, as is self-evident. As was indicated earlier in the specification, the truck of this invention is especially designed lfor use with reversible pallets of the type disclosed `in my application"supra, the rear wheels 48 being intended to enter between the boards 5I of a. reversible pallet for lifting the pallet, all as is shown in Figs., 2 and 3, In order that the truck may enter between the upper and lower floors of such a platform, I'equip the rear end of each\ of the platform legs of my truck with a series`of rollers 52, whose positions are so graduated that rst one of\the rollers will contact the platform, thenthe second, and .then the third,

graduallly lifting each of the\platform legs intothe space between the upper and lower floors.

`VMoreover, rthe series of rollers 52 assistY in facilitating the movement of the truck to its position of-Fig.`2 relatively to the reversible pallet by cooperation witheach of the successive lower floor boards 5I. 1

Similarly, to assist in withdrawing the truck from between the upper and lower floors of a reversible pallet, I employ a further series of roll- -ers 53, whose operation will be readily understood. Additional rollers 54 further assist in the moi/ement of the platform legs 2I into and out I VYof the pallet.

Incidentally, it will be well to indicate at this AVtime that I 'utilize the spread platform legs 2| because the floors of the usualtype of reversible skid pallet are separated by a longitudinal beam, not herein shown, the platform legs 2| being A adapted to enter the pallet on each side of said longitudinal beam, all as is best setk forth in my application supra.

As I have already explained, lifting movement of theelevating platform of my truck is imparted thereto`by`vertical movement thereof on the upper and lower links '26 and 36 relatively to the lifting head I0. Those skilled in the art will well appreciate that the upper and lower lifting links 26` and 36 act to maintain the platform in parallelogram 'relationship to the lifting head IU, whereby so long as the platform legs 2| comprising the lifting platform of the truck, are maine tained parallel to the ground, the lifting head I0 will be maintained perpendicular to the ground, all as is desirable in this art. Where the floor is horizontal, the lifting head III will bemaintained in a vertical plane, which is desirable for best operation thereof. The relationship of the rear lifting links I41 to the upper and lower lifting links 26 and 36 is, of course, preferably as has already been indicated, so that the rear end of the elevating platform will be lifted at substantially the same rate as the front end thereof.

K Since, as has already been indicated, vertical movement of the elevating platform relatively to the lifting head I0 actsl to move 'the wheels'48 carried by the rearl lifting links 41, from the-posi tion of Fig. 2 toward the position lof Fig. 43, it will be readily appreciated that when the extreme rear rollers 52 of the platform legs 2| 'first encounter a board 5| of the pallet, those rollers 52 will act toflift the 'pair of platform legs 2l and Each of the rods 43 is,

. Y 2,274,164 therefore the entire platform including the sad.

die 22, relatively tothe lifting head i0. Ihisis particularlyV true when vusing mechanical lifting meansof the type herein disclosed, andwhich are readily movable through the .application of lifting pressure to the platform. If this relative movement were not resisted, it would cause theV links 41 to rotate towards the position of Fig. r3,-

bringingthe wheels 4B down below their position in Fig. 2,- so .that the said wheels would forma lconsiderable obstruction against the` movement of 4the l'platform legs 2i further into-the space between the upper and lower floors 'of the reversible pallet. As a matter of fact, such movement of the wheels wouldfoifset all ofthe benefitsobtained by the utilization ofthe rollers 52',- and also of the rollers 53 and 54.

1. -I therefore provide springs 55 which are mount-rv ed about each of the rods 43 and press at Aone end against a plate 56 secured to the side bars 30 other, ends, the springs v55 press 'against an "ade justable nut\51 on therods 43. 'I'he springs 55 .therefore function to prevent rotation of the links Y 41 from'the position of Fig. 2 to the position of Fig. 3 when the elevating platform is lifted relatively to the lifting head |0` throughv the applica-` v f tion'of lifting pressure to the platform itself. Y

" Infthis way, when the platform is liftedr somee whatias inV the' position or Fig. 2, the wheels. 4s.

will notmove downwardly to obstruct the opera l tion ofthe rollers 52, 53 and 54. Rather, the en'` tire .truck will pivot aboutthe wheels ii under the .lifting head." Naturally, when the lifting mechanism itself is actuated andthe lifting links I9 are rotated, moving the lifting struts 34, there 2o and`33`of each of the platform legs 2|. At their will be a forceful separation between the lifting 'head i0 andthe lifting platform, causing an up- 'ward movement of the -platform and a corresponding downward movement of the Awheels 48 wat the rear ends of'each ofthe platform legs 2|.V

In order to effect a smooth lowering of the'lifting platform when the holdingpawl .i1 is released, I employ a liquid dashpot 58 4of the typev standard in this art. The plunger portion 58a ofthe dashpot 58. is 'secured at its upper end unit about the n wheels headlmounted about said rods., whereby app cationof lifting pressure` to the said platform end to said liftinghead whereby to maintain a parallelogram.` arrangement between said links, said platform #and said lifting head, means for movlngtheplatform upwardly relatively to said f lifting head through said links,- rods extending from at least certainof said` links for moving vertically the wheels supporting the rear end of ,said platform whereby to lift simultaneouslythe frontfand rear ends of said platform, guide lugs on 'l said platform through which said rods extend,.springs mounted about said rods and pressying at one end against said lugs and at the other end against a stop on said rds, and said springs resisting said movement ofsaid platform relatively to said head, whereby application of lifting pressure to the said platform other than through Y said lifting head means will merely tilt said platform and'lifting'head as a unit about the wheelsy supporting said lifting head.

3. jIn alift truck; a lifting head, wheels supporting said lifting head, an elevating platform,

wheel supporting links plvoted to the -rear .end

of. said platformlinks secured at one end tothe front end of said platform and at their other end to thev lifting head whereby to form an assembled truck` and with the front end of the elevating lplatform supported by said lifting head,'rods connecting said .rear wheel supporting'links to "said front end links, means on said liftingv head porting links whereby to liftsimultaneously both n through suitable linkage mechanism to a pair of angle irons l59 welded to the upper end of the v saddle 22 near the portionl 23 thereof, The lower end of the dashpot 5B is pivoted through a shaft l60 to the lowerV end 6| of a bracket 62 which is secured as-4 by welding at 63 to the rear plate of the lifting head i 0. The dashpot 58 being mounted in the particular position shownvery readily .follows the upward movement of the elevating platform and readily controls the downward lowering movement of the platform. i

./'Having now described a preferred modification rf of my-invention, Iclaim 1. In a lift truck, alifting head, wheels s up- :porting said lifting head, an elevating. platform, I

wheel -supporting linksgpivoted to the` rear end of said platform, supporting means securing the front end of said platform to the lifting' head whereby to form an assembled truck, rods connecting said rear'wheel supporting links to said supporting meansmeans on'said. lifting head for' moving said platform upwardly relatively to said lifting head and throughsaid supporting means and thereby to effect a movement Vof .both, said Vsupporting means and said rear wheel supporting links. whereby to liftsimultaneously both Vends of said platform, and springs for resisting e movement of `said platform relatively to said for moving said platform upwardly relatively tol said lifting head 'and through' said front end links, and thereby. to effect a pivotal movement of said front end links and said rear wheel supends of said platform," guide'lugs on said elevating platform for guiding' said rods, and springs mounted on said'rods and pressing against said .guide lugs for resisting movement of said platform relativelyV to said head on said links, whereby application of lifting pressure to the said platform other than through said lifting head means will merely tilt said platform and lifting head as e a unit. about the wheels supporting said lifting head.

4. In alift truck, anfang head, wheels sup-nV porting said lifting head, an elevating platform, wheel supporting links pivotedto the rear endpf` said platform, supporting means securing the front end of said 4platform to' the lifting headwhereby to for-m anassembled truck, rodsy con.-

necting said rear wheel supporting links to said supporting means, guide lugs on said platform traversed by said rods, means o n said lifting head for moving said platform upwardly relatively to j saidflifting head and through said supportingmeans, and thereby to effect movement of both said supporting means'and said rear wheelsupporting links whereby to lift simultaneously both ends of said platform, rollers at the rear end of l said platform and rearwardly of said wheels whereby said rollers tend to lift said platform as vsaid rollers encounter an obstruction. and

springs mounted about said rods and pressing said plat/form, a vertically extending saddle atthe front YendV of v said platform, upper and lower links each pivoted at one'end to said saddle and at the other..

against said guide lugs for resisting movement of said platform by said rollers relatively to said head, whereby application oflifting pressure to the said platform by said rollers will merely tilt said platform and lifting head as a unit about the wheels supporting said lifting head.'

5. In a mozaiek of the cmssdescribed, a nrting head, an elevating platform having a vertical hollow standard juxtaposed to said liftinghead and enclosing a portion of said lifting head, up-

. per and lower parallel links pivoted at their front ends'toy the lifting head and at their rear ends to"said standard, a `dashpot vertically disposed within said standard and pivoted at its lower en'd to'said lifting head and at its upper end to said standard, wheel supporting links pivoted to the ing head, effects the rotation of said links to lift the rear end of said platform, and means on said lifting head for so lifting said platform.

rear of said elevating'platform,` means `connectfing said wheel= supporting -links to atleast certain of said parallel links whereby movement of said parallel links'as the front end of said platform is elevated vrelatively to said/.lifting head, effects VVthe rotation of said links to lift the rear end of vsaid platform, and means on said lifting head for so lifting said platform. f,

6. In a lift truck of the class described, a lifting head, an elevating platform having a vertical hollow standard juxtaposedto said lifting head,

upper andv lower parallellinks pivoted at their p front endstolthe-lifting head and at their rear ends to said standard, a dashpot vertically dis-` posed within said standard and pivoted at its lower end 'toY said lifting head and at its upper end to said standard, Wheel vsupporting links "pivoted to Vthe rear of said elevating platform, means connecting said wheel supporting links to at least certainof said parallel links whereby movement'of said of said platform is elevated relatively to said liftparallel links as thevfront end f lib.

fz. rn a lift truck of the class described, a iiftend to said standard, wheel supporting links piv-` oted to the rear of said elevating connecting said wheel supporting platform, means links to at least 'certain of said parallel links whereby movement of `said parallel links as the front endof said platform is elevated relatively to said lifting head, effects the rotation of said links to lift the Vrear end of said platform, and means extending between said lifting head and said lower parallel links for actuating said links to lift said platform.

8. In a lift truck ofthe class described, a lifting head, an elevating platform having a vertical standard juxtaposed to said lifting head, upper and lower parallel links pivoted at their front ends to thelifting head and at their rear ends t'o said standard, wheel supporting links pivoted to the rear of said elevating platform, means connecting said wheel supporting links to at least certain of said parallel links whereby movement of said parallellinks as the front end of said platform is elevated relatively to said lifting head, effects the rotation ofsaid links to lift the rear end of Asaid platform, and means extending between said lifting head and said lower parallel links for actuating said links to lift said platform.

GEORGE QUAYLE.

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