US2417396A

US2417396A - Pallet truck

Info

Publication number: US2417396A
Application number: US503745A
Authority: US
Inventors: Herbert J Framhein
Original assignee: Yale and Towne Manufacturing Co
Current assignee: Yale and Towne Manufacturing Co
Priority date: 1943-09-25
Filing date: 1943-09-25
Publication date: 1947-03-11
Anticipated expiration: 1964-03-11

Description

March 11, 1947. J FRAMHEIN.

PALLET TRUCK Filed Sept. 25, 1943 4 Sheets-S eet 1 INVENTOR .14. J7? M 4 mw hm mm ATTORNEY March 11, 1947. H. J. FRAMHEIN PALLET TRUCK Filed Sept. 25, 1943 4 Sheets-Sheet 2 v-z, h 464/- BY ATTORNEY March 11, 1947. H. J.'FRAMHEIN PALLET TRUC K Fil ed Sept. 25, 1943 4 Sheets-Sheet 3 INVENTOR V F MM ATTORNEY H. J. FRAMHEIN 2,417,396

PALLET TRUCK March 11, 1947.

' 4 Sheets-Sheet 4 Filed Sept. 25, 1943 R 3 R m E V u \m m i w w y W f .m x.. ...L...

w 7.1%; .1 48,; BY 5? r ATTORNEY Patented Mar. 11, 1947 PALLET TRUCK Herbert J. Framhein, Chicago, Ill., assignor to The Yale & Towne Manufacturing Company, Stamford, Conn., a corporation of Connecticut Application September 25, 1943, Serial No. 503,745

Claims.

This invention relates to industrial lift trucks, and more particularly to industrial lift trucks of the type shown in my application Serial No. 458,035 filed September 11, 1942. In that application I disclose a basic improvement in industrial trucks of the type adapted for cooperation with pallets, and more particularly, I disclose new and novel means for facilitating the entry of the load platform of an industrial truck between the floors of a pallet.

In brief, this is accomplished in my invention through the provision of means for maintaining the load lifting wheels at the rear of the elevating platform in an elevated position when the elevating platform is in its fully lowered position. Intermediate wheels are preferably provided for supporting the truck for movement when the load lifting wheels are elevated, the lifting of the elevating platform through the movement of the load lifting wheels acting to raise the intermediate wheels so that they will not interfere with the movement of the truck.

Modifications of the invention disclosed in the said application supra, are set forth in my application Serial No. 469,324 filed December 17, 1942, and Serial No. 493,701 filed July '7, 1943. In the present application I illustrate a further modification of my invention applied to trucks of the class in which the lifting wheel links at the rear of the elevating platform are actuated by the links pivotally connecting the forward end of the elevating platform of the truck to the lifting head. In order to simplify the description of this modification of my invention I shall show it applied to the trucks of this class disclosed in the Quayle Patent No. 2,274,164 granted February 24, 1942, and in the Hastings Patent No. 2,234,925 granted March 11, 1941. A reading of those patents will be helpful toward a fuller understanding of this invention.

In brief, the object of my invention disclosed and claimed in this application is the adaptation of a truck of the class indicated for facilitated cooperation with a pallet.

As one feature of my invention through which the objectives thereof are obtained, the front connecting links between the elevating platform and the lifting head are adapted to hold the rear.

wheel lifting links in position to maintain the lifting wheels off the ground when the elevating platform is in its fully lowered position. A further feature of my invention resides in the use of intermediate wheels, preferably secured to the elevating platform, for supporting the truck for' movement when the elevating platform is lowered and the lifting wheels are off the ground. As a still further feature of my invention the intermediate wheels are raised off the ground as v the lifting wheels are lowered and the elevating platform is lifted.

I have thus outlined the more important features of my invention in order that my contribution to the art may be better understood and in order that the relation of my contribution to the prior art may be better comprehended. I do believe that my contribution is a broad and valuable one and that I am entitled to patent claims that will prevent newcomers in the field from utilizing my contribution to the art with such variations in physical structure as will readily occur to those skilled in the art. Also, while I have described generally several important features of my invention, there are other important features that will be described particularly in the specification and will be claimed in the claims appended hereto.

Referring now to the drawings:

Fig. 1 illustrates in vertical partial section a truck to which my invention is applied.

Fig. 2 is'a perspective view of one of the forward links connecting the elevatingplatform to the lifting head and adapted to actuate the rear lifting wheel links.

Fig. 3 is a view similar to Fig. 1 showing the elevating platform in an elevated position.

Fig. 4 is a plan view of the truck of Figs. 1 and 3.

Fig. 5 is a view similar to Fig. 1 showing a modified form of truck in which the elevating platform is pivoted in a somewhat different manner to the lifting head.

Fig. 6 is a perspective view of the linkage mechanism whereby the rear lifting wheels of the second modification are actuated.

Referring first to Figs 1-4, the lifting head of the truck is designated by reference numeral l0 and is shown supported by a steering head II having a steering wheel l2. A hydraulic pump is designated by reference numeral l3 and is actuated by a treadle I4. A release treadle l5 for the hydraulic pump I3 is adapted to control the lowering movement of the elevating platform as will hereinafter be set forth.

The elevating platform is designated generally by reference numeral l6 and is of the U type.

having a pair of legs each designated by reference numeral [1. The forward end of the elevating platform I6 is in the form of a vertical standard l8 that is pivotally connected to a vertical standard [9 of the lifting head ID. The connection is made at the upper end of the elevating platform standard is through a pair of links 23 pivoted to the lifting head standard l9 at 2|, and

to the elevating platform standard at 22.

The lower end of the elevating platform standard i8 is pivoted to the lower end of the lifting I8 of the lifting platform i6 has at each side a pair of brackets 25 on which is mounted a shaft 26, each link 23 being pivotally supported on the standard 18 through one of the shafts '26 The l forward end of each link 23 is' supported reiag tively to the lifting head by a shaft 27 secured at each end by a nut 28 relatively to the said 1 links 23. It is now readily seen that the-elevat-- ing platform may be swung through upper links 29 and lower parallel links 23 relatively to the lifting head so as to be elevated relatively thereto.

The lifting of the front end of the elevating platform it on the upper and lower links is acpivoted at its lower end at 31 on the lifting head,

' and at 32 relatively to the standard It. The rear end of the elevating platform It is adapted for lifting movement simultaneously with the forward end, this action being accomplished by the pivotal movement of the rear wheel lifting links 35 complished by the hydraulic ram assembly 39 i pivoted at 36 to each of the legs 11 of the elevating platform I6 Each link carries a lifting wheel 31 and is pivoted at 38 to a tension rod 39 that extends forwardly, and as best shown inFig. 3

is pivoted at '43 to one of the links 23.

" In the usual type of truck as disclosed in the Quayle patent, when the elevating platform is in its lowered position of Fig, 1, the links 23; rods 39 and lifting wheel links 3 5 are positioned so that the wheels 3? are against the ground G.

' In such trucks it is relatively difficult to move the elevating platform into position between the boards at of a paint P shown in Fig. 1, and numerous eirpe'dients have been suggested. In my truck, the arrangement of the parts is such that when the elevating platform is in its fully lowered position of Fig. 1, the rear lifting wheels .31 are held up and away from the ground as illustrated. This action is made possible by the particular novelarrangement of the rear wheel lifting links 35, the rods 39 and the links 23relatively to one another, all as is clearly shown in my drawings.

For pressing the elevating platform into its position of Fig. 1; that is, into its fully lowered position, I utilize a pair of springs 45. Each of these springs 45 is mounted about a shaft 46 that through the bifurcated shackle 4'! is secured at 48 to the elevating platform 16. Each spring 45 presses at its lower end against a disk 59 adjustably secured by nuts 51! to the rods 18. At its upperend eachspring d5 presses against the lifti'n'g head through the medium of a rounded washer from the elevating platform.v

preferably one wheel at each side of the truck.

form is in its fully lowered position and is maintained in that position by the springs 45. The links 23 in cooperation with rods '39 hold the rearwheel lifting links 35 in position maintaim. ing the lifting wheels 37 off the ground. The truck is therefore very easily moved into position with its load platform between the floors of the pallet P.

Operation of the lifting treadle it of pump l3 effects the actuation of the lifting ram assembly st to Hit the elevating platform through swinging movement thereof on, upper links 26 and'lower links 23. The disposition of the parts is such that the links 255 will first impel swift movement of the rear wheel lifting links 35 toward the position of Fig. 3. This will of course act to lift the rear end of the elevating platform as the forward end is lifted by the rain of assembly 30. It will also act to lift the intermediate wheels 55 off the ground while continuing the upward movement of the elevating platform at its front and rear ends. The final lifted position of the elevating platform is of course illustrated in Fig; 3. There, the intermediate wheels are off the ground, and lifting wheels 3? are fully down and holdthe rear end of the elevating platforrri fully lifted. 7

If the release treadle [*5 is now depressed, the elevating platform will be lowered under the influence of the load'and the springs 55. Lowering movement of the elevating platform will of course effect the lifting of the wheels 31' off the ground and the bringing of the intermediate wheels 55 against the ground'as in Fig; 1. I believe that from the brief description herein given; the operation of this modification of my invention will be clearly understood. Naturally, a fuller understanding of the invention will be possible after a reading of the specifications of my earlier applications referred to above, and possibly a reading of the Quayle patent.

In Fig. 5 I show a modification of my invention utilizings'ubstantially the arrangement of the parts illustrated in Figs. 1%. However, uh like the truck of my first modification, the 'ele vating platform of 5 extends forwardly relatively to the liftinghead so that the connecting links between the lifting head and elevating platform are secured at their forward ends to the 'ele vat'ing platform and at their rear ends to the lifting head. Thus,'upper links 50 are pivoted at 6|" to the elevating platform and extend rearwardly and are pivoted at 62 to the lifting head. Similarly, the Iowerimks 83, best shown in Fig; 6, are pivoted at their forward ends through shafts of to the elevating platform. The links then extend 're'arwardly and are pivoted through a shaft 65 to the lifting head 66, the lifting head provided with the sleeve 6? for the passage of the shaft 65, I

The rods extendingfrom the rear wheel lifting links :68 are designated by reference numerals 69 and take the place of rods 33 oftne first modi- U shaped member II are through stub shafts '13 secured to the links 63 for actuation by the said links, all as clearly seen in Fig. 6. In the full line position of the parts in Fig. 5, the elevating platform is lowered and the intermediate wheels 55 are against the ground. The lower connecting links 63, through the U member TI and the rods 69, hold the rear wheel lifting links 68 so that the lifting Wheels 3'! are maintained spaced from the ground as in the first modification. In the dash and dotted line position of the parts, the elevating platform is shown in its lifted position. The forward end of the platform moves upwardly and rearwardly to the lifted position, with the

links

60 and 63 moving as shown to their dash and dotted line positions. The U member 7! is actuated by links 63 and through rodstii swings the lifting links 68 downwardly, thus lifting the rear end of the elevating platform. Those skilled in the art will of course now fully appreciate the operation of the second modification of my in- Vention.

I now claim:

1. In a lift truck of the class described, a wheel supported lifting head, an elevating platform, connecting links pivotally connecting the forward end ofsaid platform to said lifting head, lifting means for lifting the front end of said elevating platform relatively to said lifting head through swinging movement thereof on said links, intermediate wheels on said elevating platform contacting the ground for supporting said platform when it is in its lowered position relatively to said lifting head, lifting wheel links pivoted to the rear of said elevating platform, lifting wheels on the said lifting wheel links adapted to contazt the ground to lift the rear end of said elevating platform as said liftingv wheel links swing downwardly relatively to said platform, means of connection so connecting said lifting wheel links and said connecting links that said connecting links hold said lifting Wheel links in position to maintain said lifting Wheels off the ground and with the plane of the lowermost portions of their peripheries above the plane of corresponding portions of the peripheries of said intermediate wheels when said elevating platform is in its fully lowered position relatively to the ground and said lifting head, the swinging of said connecting links incidental to the lifting of said elevating platform by said lifting means acting through said means of connection to swing the lifting wheel links downwardly to lift the rear of said elevating platform.

2. In a lift truck of the class described, a wheel supported lifting head, an elevating platform, connecting links pivotally connecting the forward end of said platform to said lifting head, lifting means for lifting the front end of said elevating platform relatively to said lifting head through swinging movement thereof on said links, intermediate wheels for supporting said elevating platform for movement on the ground when it is in its fully lowered position relatively to said lifting head, lifting wheel links pivoted to the rear of said elevating platform, lifting wheels on the said lifting wheel links adapted to contact the ground to lift the rear end of said elevating platform as said lifting wheel links swing, downwardly relatively to said platform, means of connection so connecting said lifting wheel links and said connecting links that said connecting links hold said lifting wheel links in position to maintain said lifting wheels off the ground and with the plane of the lowermost portions of their peripheries above the plane of corresponding portions of the peripheries of said .intermediate wheels when said elevating platform is in its fully lowered position relatively to the ground and said lifting head, the swinging of said connecting links incidental to the lifting of said elevating platform acting through said means of connection to swing the lifting wheel links downwardly to lift the rear of said elevating platform.

3. In a lift truck of :the class described, a wheel supported lifting head, an elevating platform, connecting links pivotally connecting the forward end of said platform to said lifting head, lifting means for lifting the front end of said ele-, vating platform relatively to said lifting head through swinging movement thereof on said links, intermediate wheels on said elevating platform contacting the ground for supporting said platform when it is in its lowered position relatively to said lifting head, lifting wheel links pivoted to the rear of said elevating platform, lifting wheels on said lifting wheel links adapted to contact the ground to lift the rear end of said elevating platform as said lifting wheel links swing downwardly relatively to said platform, rods so securing said lifting wheel links and said connecting links that said connecting links hold said lifting wheel links in position to maintain said lifting wheels off the ground and with the plane of the lowermost portions of their peripheries above the plane of corresponding portions of the peripheries of said iiitermediate wheels when said elevating platform is in its fully lowered position relatively to the ground and said lifting head, the swinging of said connecting links incidental to the lifting of said elevating platform acting through said rods to swing the lifting links downwardly to lift the rear of said elevating platform.

4. In a lift truck of the class described, a lifting head having a vertical standard, an elevating platform having a vertical standard at its forward end, connecting links pivotally connecting the standard of said platform to the vertical standard of said lifting head, lifting means for lifting the front end of said elevating platform relatively to said lifting head through swinging movement thereof on said connecting links, intermediate wheels on said elevating platform contacting the ground for supporting said platform when it is in its lowered position relatively to said lifting head, lifting Wheel links pivoted to the rear of said elevating platform, lifting wheels on the said lifting wheel links adapted to contact the ground to lift the rear end of said elevating platform as said lifting wheel links swing downwardly relatively to said platform, means of connection so connecting said lifting wheel links and said connecting links that said connecting links hold said lifting wheel links in position to maintain said lifting wheels off the ground and with the plane of the lowermost portions of their peripheries above the plane of corresponding portions of the peripheries of said intermediate Wheels when said elevating platform is in its fully lowered position relatively to the ground and said lifting head, the swinging of said connecting links incidental to the lifting of said elevating platform acting through said means of connection to swing the lifting links downwardly to lift the rear of said elevating platform.

5. In a lift truck of the class described, a wheel supported lifting head having a vertical standard, an elevating platform having a vertical standard at its forward end, connecting links pivotally connecting the standard of said platform aeimao through swinging movement thereof on said links,

lifting wheel links pivoted to the rear of said elevating platform, lifting wheels on the said lifting wheel links adapted to liftthe rear end of said elevating platform as said lifting wheel links swing downwardly relatively to said platform, means of connection so connecting said lifting wheel links and said connecting links that said connecting links hold said lifting wheel links in a retracted position relatively to said elevating platform to maintain said lifting wheels I off the ground when said elevating platform is in its fully lowered position, the swinging of said connecting links incidental to the lifting of said elevating platform acting through said means of connection to swing the lifting links downwardly to lift the rear of said elevating platform, and intermediate wheels on said elevating platform having their peripheries below the peripheries of said lifting wheels when said lifting links are retracted relatively to said elevating platform, whereby said intermediate wheels contact the ground to support said platform when it is in its lowered position with said lifting wheels raised off the ground.

6. Ina lift truck of the class described, a wheel supported lifting head, an elevating platform, connecting links pivotally connecting the for ward end of said platform to said lifting head, lifting means for lifting the front end of said elevating platform relatively to said lifting head.

ing the elevating platform for movement when it 1 is in its fully lowered position relatively to said lifting head, lifting wheel links pivoted to the rear of said elevating platform, lifting wheels on the said lifting wheel links adapted tocontact the ground to lift the rear end of said elevating platform as said lifting wheel links swing downwardly relatively to said platform, means of connection so connecting said lifting wheel links and said connecting links whereby said connecting links hold said lifting wheel links in position to maintain said lifting wheels off the ground and with the plane of the lowermost portions of their peripheries above the planeof corresponding portions of the peripheries of said intermediate wheels when said elevating platform is in its fully lowered position relatively to the ground and said lifting head, the swinging of said connecting links incidental to the lifting of said elevating platform acting through said means of connection to swing the lifting wheel links downwardly to lift the rear of said elevating platform.

'7. In a lift truck of the class described, a wheel supported lifting head having a vertical standthrough swinging movement thereof on said links, spring means pressing said elevating platform into,

its fully lowered position relatively to said lifting head, lifting wheel links pivoted to the rear of said elevating platform, lifting wheels on the said lifting wheel links adapted to lift the rear end of said elevating platform as said lifting wheel links swing downwardly relatively to said platform, means of connection so connecting said lifting wheel links and said connecting'links that said connecting links hold said lifting wheel links in a retracted position relatively to said ele'vat, ing platform to maintain said lifting wheelsofi the ground when said elevating platform is in 1ts fully lowered position relatively to the ground and said lifting head, the swinging of said connecting links incidental to the lifting of said elevating platform acting through said means of connection to swing the lifting links downwardly to lift the rear of said elevating platform, and intermediate wheels on said elevating platform having their peripheries below. the peripheries of said lifting wheels when said lifting links'are retracted relatively to said elevating platform, whereby said intermediate wheels contact the ground to support said platform when itlis in its lowered position with said lifting wheels raised off the ground. a I

8. In a lift truck of the class described, a wheel supported lifting head, an elevating platform, connecting links pivotally connecting the forward end of said platform'to said lifting head, said links being pivoted at their rear ends to the lifting head, and at their forward ends to the elevating platform, lifting means on said lifting head adapted to lift the front end of said elevating platform relatively to said lifting head through swinging movement thereof rearwardly and upwardly on said links, intermediate wheels on said elevating platform contacting the ground for supporting said platform when it is in its lowered position relatively to said lifting head, lifting wheel links pivoted to the rear of said elevating platform, lifting wheels on the said lifting wheel links adapted to contact the ground to lift the rear end of said elevating platform as said lifting wheel links swing downwardly relatively tosaid platform, rods connecting said lifting wheel links and said connecting links whereby said connecting links hold said lifting wheel links intion. to maintain said lifting wheels off the ground and with the plane of the lowermost portions of their peripheries above'the plane of corresponding portions of the peripheries of said intermediate wheels when saidelevating platform is in its fully lowered position relatively to the ground and said lifting head, the swinging of said connecting links incidental to the lifting of said elevating platform acting through said rods to swing the lifting wheel links downwardly to lift the rear of said elevating platform. 7 l 9. In a lift truck of the class described, a lifting head, an elevating platform, connecting links pivotally connecting the forward end of said platform to said'lifting head, lifting means adapted to lift the front end of said elevating platform relativelyto said lifting head through swinging movement thereof on said links, lifting wheel. links pivoted. to the rear of said elevating platform, lifting wheels on the said lifting'wheel links adapted to lift the rear endof said elevating platform as said lifting wheel linkssw'rng downwardly relatively to said platform, means connecting said lifting wheel links and said con--,

necting links so that said connecting links hold said lifting wheel links in a retracted position relatively to said elevating platform to maintain said lifting wheels off the ground when sai'delevatingplatform is in its fully lowered position relatively to the ground and said lifting head, the swinging of said connecting links incidentalto the lifting of said elevating "platform acting;

through said means of connection to swing the lifting links downwardly to lift the rear of said elevating platform, and intermediate wheels positioned with their peripheries below said lifting wheels when said lifting links are in said retracted position for supporting said truck when said platform is in its lowered position relatively to said lifting head with said lifting wheels raised off the ground.

10. In a lift truck of the class described, a lifting head, an elevating platform, connecting links pivotally connecting the forward end of said platform to said lifting head, lifting means for lifting the front end of said elevating platform relatively to said lifting head through swinging movement thereof on said links, intermediate wheels on said elevating platform contacting the ground for supporting said platform when it is in its lowered position relatively to said lifting head, lifting wheel links pivoted to the rear of said elevating platform, lifting wheels on the said lifting wheel links adapted to lift the rear end of said elevating platform as said lifting wheel links swing downwardly relatively to said platform, a U member pivoted at each leg of its U form to one of said connecting links, means connecting said lifting wheel links to said U member arranged so that said connecting links through said U member hold said lifting wheel links in a retracted position to maintain said lifting wheels off the ground and with the plane of the lower most portions of their peripheries above the plane of corresponding portions of the peripheries of said intermediate wheels when said elevating platform is in its fully lowered position relatively to the ground and said lifting head, the swinging of said connecting links incidental to the lifting of said elevating platform acting through said U member and connecting means to swing the lifting wheel links downwardly to lift the rear of said elevating platform.

- HERBERT J. FRAMHEIN.

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

UNITED STATES PATENTS Number Name Date 2,361,544 Hastings 0st. 31, 1944 2,358,957 Barrett Sept. 26, 1944 2,274,164 Quayle Feb. 24, 1942 2,110,424 Quayle Mar. 8, 1938