US3151755A

US3151755A - Scissor lever with a pivotal link for shifting and tilting the mast on an industriallift truck

Info

Publication number: US3151755A
Application number: US113811A
Authority: US
Inventors: George F Quayle
Original assignee: Yale and Towne Inc
Current assignee: Yale and Towne Inc
Priority date: 1961-05-31
Filing date: 1961-05-31
Publication date: 1964-10-06
Anticipated expiration: 1981-10-06
Also published as: GB957995A

Description

Oct. 6, 1964 QUAYLE 3,151,755

SCISSOR LEVER WITH A PIVOTAL LINK FOR SHIFTING AND TILTING THE MAST ON AN INDUSTRIAL LIFT TRUCK Filed May 31, 1961 3 Sheets-Sheet l INVENTOR. GOQGc' F Qua YLE Ar ow/ r Oct. 6, 1964 G. F. QUAYLE 3,151,755

SCISSOR LEVER WITH A PIVOTAL LINK FOR SHIFTING AND TILTING THE MAST ON AN INDUSTRIAL LIFT TRUCK Filed May 51, 1961 I5 Sheets-Sheet 2 \q 10 1 l1 9 v R. 660966 Quay:

Oct. 6, 1964 G. F. QUAYLE 3,151,755

SCISSOR LEVER WITH A PIVOTAL. LINK FOR SHIFTING AND TILTING THE MAST ON AN INDUSTRIAL LIFT TRUCK 3 Sheets-Sheet 3 Filed May 31, 1961 Q Tic-k4- INVENTOR. G'oms QUAYLE United States Patent 3,151,755 SCISSOR LEVER W11 H A PIVOTAL LmK FGR SHWTKNG AND TELTENG THE MAT 6N AN INDUSTRIAL LIFT TRUCK George F. Quayle, Philadelphia, Pa., assignor, by mesne assignments, to Yale & Towne, Inc, New York, N.Y., a company of Ohio Filed May 31, 1961, Ser. No. 113,811 9 Claims. (Cl. 214-670) This invention relates to an industrial lift truck of that type in which a fork or other load lifting member is adapted to move inwardly and outwardly relatively to the truck. This makes possible the movement of the load lifting fork into an extended or reach position in which the fork may lift a load that it could not otherwise handle. The load lifting fork or member, once it engages the load, can retract the load to a position toward or actually within the confines of the trucks so that the irutk will be stable and may more effectively move the Most frequently, trucks of the particular type utilize conventional uprights that are mounted through bearings on rails or channels positioned linearly of the truck. Through suitable linkage or direct thrust means, the uprights may he moved inwardly or outwardly on the rails or channels relatively to the truck, as those skilled in the art will appreciate.

In an arrangement of that kind, it is very important that the uprights, on which a conventional set of forks are usually mounted for vertical movement, be adapted for tilting movement. Such tilting movement is very dimcult to obtain effectively because of the nature of the means used for moving the uprights inwardly and outwardly, and the nature of the means used for mounting the forks for this inward and outward movement.

I have conceived by my invention a very novel and simple arrangement whereby I am able to mount a pair of uprights for inward and outward movement relatively to a truck in combination with means for so moving the uprights, while at the same time stabilizing the uprights and holding the uprights in any stabilized position, which position may be a tilted position.

As a feature of my invention, 1 utilize a linkage mechanism for moving the uprights outwardly and inwardly, with the uprights being preferably mounted on a hearing that will permit this movement, while at the same time allowing a tilting movement of the uprights. My preferred and most effective arrangement provides a single roller type bearing for each upright, that bearing moving in a channel. Obviously, the roller for each upright will support that upright for movement inwardly and outwardly of the truck, while allowing each upright to tilt on the bearing axis of the roller. Those skilled in the art will appreciate that while I have here set forth a very simple type of bearing arrangement, it is possible to use a more complex arrangement for moving the uprights inwardly and outwardly and, at the same time, permitting the tilting of the uprights.

For movin the uprights inwardly and outwardly, I prefer a linkage arrangement in the form of a pair of pivoting levers, which levers may take a scissors form. Preferably, one of the levels of the scissors is pivoted to a fixed portion of the truck while the other end of the particular lever slides relatively to the uprights. Similarly, the other lever is pivotally and swingably connected to a moving upright while slidingly connected to a fixed portion of the industrial truck. I have developed, further, rather novel means for operating the scissors relatively to one another and for permitting the tilting of the uprights relatively to the scissors mechanism.

In the particular arrangement, I have conceived the EJ5135 5 Fatented Get. 6, 1964 feature of forming one of the scissors levers in two parts, which two parts are pivotally connected to one another and may function as a single part when a hydraulic ram extending between the two parts is held rigid. This hydraulic ram may be actuated to vary the relationship between the two parts of the lever, thereby eflecting the tilting of the moving uprights.

I have thus outlined rather broadly the more important features of my invention in order that the detailed description thereof that follows may be better understood, and in order that my contribution to the art may be better appreciated. There are, of course, additional features of my invention that will be described hereinafter and which will form the subject of the claims appended hereto. Those skilled in the art will appreciate that the conception on which my disclosure is based may readily be utilized as a basis for the designing of other structures for carrying out the several purposes of my invention. It is important, therefore, that the claims be regarded as including such equivalent constructions as do not depart from the spirit and scope of my invention, in order to prevent the appropriation of my invention by those skilled in the art.

Referring now to the drawings:

FIG. 1 shows a perspective view of an industrial truck utilizing my novel shifting uprights;

FIG. 2 is a front view showing parts of my invention that support the uprights;

FIG. 3 shows a side view of my invention;

FIG. 4 is like FIG. 3 but shows the uprights in an extreme inward position;

FIG. 5 illustrates somewhat diagrammatically the tilting of the uprights.

For the purpose of describing my invention, I show in FIG. 1 an industrial truck 1% that is U-shaped, in effect bein constructed with two

portions

11, 12 that are spaced so as to leave an opening 13 extending through one side of the truck. The truck it; utilizes the novel arrangement of my invention to support and to move an upright assembly 14 relatively to the opening 13 on the truck. The upright assembly 14 supports a pair of load lifting forks 15 for vertical movement, and may have a conventional construction. As shown, assembly 14 has an outer pair of primary uprights 15 on which slide an inner pair of secondary uprights 17, a fork carriage 18 in turn being mounted to slide vertically on secondary uprights 17. The details of the upright assembly 14 are not actually important to an understanding of my invention, and it is merely necessary to know here that there are uprights on which the forks 15 are mounted.

In the extremely novel concept of my invention, I support the upright assembly 14 through a pair of simple hearings or rollers 19, best seen in FIG. 2. Each single roller 19 is mounted to rotate on a bracket 20, that bracket being welded to a corresponding primary upright 16 and to a cross member 21 extending between uprights 16, each roller in eifect supporting one upright 16. As shown in FIGS. 1 and 3, the brackets 29 extend in a direction to place rollers 19 some distance behind the uprights 16.

The rollers 19 are engaged with a pair of horizontal rails or channels 22, FIGS. 1 and 2, that are so mounted on the

portions

11, 12 of the truck as to extend along opposed sides of the opening 13. As best seen in FIGS. 3 and 4, one end of the channels 22 is arranged below

structural frame members

23, 24 that connect the two

truck portions

11 and 12, enabling the channels to extend longitudinally between the sides of the truck. In the particular arrangement, the rollers 1? will accept the entire weight of the upright assembly 14 and support the assembly directly on the truck, while allowing the uprights to slide inwardly and outwardly relatively to the opening 13. When so sliding, the upright assembly 14 can move to extreme inner and outer positions since the rollers 19 actually may move on the channels 22 to each opposed side of the truck. It will be seen also that the rollers 1h are well adapted to allow tilting of assembly 14 about the roller axis. These things will be better appreciated as my description proceeds.

I further equip the truck 1% with a pair of vertical beams 25, FIG. 1, that are mounted in position at the rear or inner side of truck opening 13, and that support a pair of scissors levers 26, 27. I may indicate that lever 26 has opposed sides 26a, 26b mounted one on each beam 25, while lever 27 also has opposed sides 27a, 27b engaged one with each beam. However, the sides of each lever may be alike, and it will'be best for the purposes of my description to disregard the pmticular sides, and to refer in more general terms to each

lever

26, 27 while considering FIG. 3 of the drawings.

As is usual in scissors arrangements, levers 26, 27 are connected to one another through a pivot 23 at a medial point. The lever 27 is a relatively simple member, but in my invention the lever 26 has a compound construction including a relatively movable outer end part 29. In the form that I prefer, the part 29 is mounted to rotate about the pivot relatively to the remainder of lever 26. To conrol that rotation I utilize a hydraulic ram that is pivoted between an arm 31 on lever 26 and a bracket 32 on the part 29 of the lever. Normally, the ram 39 will be hydraulically locked so that the part 29 cannot rotate, and we may assume for the present that the lever 26 and its part 29 form a single rigid lever.

The inner end of lever 26 is mounted on the vertical beams 25 through a pivot 33 that is fixed to a bracket 34, as shown in FIG. 3, there actually being one pivot 33 and bracket 34 on each beam 25 as will be understood. I utilize a pair of hydraulic rams 35, one of which is shown in FIG. 3, that act between brackets 36 on the beams 25 and bell-crank pivots 37 on lever 26 whereby to rotate that lever about pivots 33. The inner end of lever 27 is equipped with rollers 33 sliding one in a channel 39 on each beam 25. On the outer end of lever 26, or in other words on its end part 29, there are rollers 40 that slide in channels 41 on the primary uprights 16. The outer end of lever 27 is connected through pivots 42 to relatively short links 43, one of which is shown in FIG. 3, these links in turn being mounted to rotate on pivots 44 relatively to the primary uprights 16.

In the novel construction I have described, the

levers

26, 27 may have a somewhat conventional scissors action that will be understood by persons skilled in the art. Thus, upon actuation of hydraulic rams 35, the

levers

26, 27 will move the upright assembly 14 inwardly or outwardly relatively to the truck. Also, the hydraulic rams 36 being rigid, the

levers

26, 27 will stabilize the uprights 14, holding them in a particular angular relation to the truck.

However, in the novel concept of my invention, the

levers

26, 27 will act in combination with the rollers 19 that support the upright assembly 14. Actually, levers 26, 27 need not accept the weight of assembly 14 because the short links 43 can rotate, leaving primary uprights 16 free in a vertical direction relatively to lever 27, while rollers 40 on link 26 naturally are vertically free in channels 41. It is then possible to design the scissors links 26, 27 without considering a problem of vertical deflection. The truck actually will support the upright assembly 14 through the rollers 19, so that there will be practically no vertical deflection, and no loss of lift or vertical alignment of the lifting forks 15. That will be true regardless of the inward or outward movements of the upright assembly 14 on the rollers 19.

,"res

Thus far, we have assumed that the hydraulic rams 36 were locked, holding the parts of lever 26 rigid. Let us now refer to FIG. 5 of the drawings to see what happens when we actuate the rams 30. When those rams rotate the lever part 29 about pivot 28 in a downward direction, that part 29 will act through the rollers 49 to tilt the upright assembly 14 in one direction to a position that is shown for example in dotted lines at Me. That tilting will take place about the axis of rollers 19, those rollers at the same time moving inwardly to the position 19a while the upper end of assembly 14 rotates on the short links 43. Similarly, should rams 39 rotate the part 29 upwardly, the upright assembly 14 will be tilted in the opposed direction to the position shown in dot and dash lines at 14b, for example, rollers 19 then moving to position 1%. Thus, by actuating the rams 30, the person operating the truck can tilt the upright assembly 14 either forwardly or rearwardly, as he may desire.

Moreover, he may do that when assembly 14 is in practically any inward or outward position to which it may slide relatively to the truck. It will be seen also that the upright assembly 14 may be moved to an extreme forward position that is actually beyond the side of the truck, since the rollers 1 are arranged behind the assembly in a position that enables them to remain engaged with the channels 22. In all cases, the truck will directly support the upright assembly 14 through the rollers 19, those rollers being extremely simple, well adapted to support the assembly for tilting movement, and arranged so that the assembly will have practically no vertical deflection due to the load.

Those persons who are skilled in the industrial truck art will now understand that I have conceived an arrangement that is extremely effective for the mounting and actuation of truck uprights, when those uprights must have inward and outward movement and also tilting movement relatively to the truck. I believe, therefore, that the exceedingly novel contribution of my invention will be fully appreciated.

I now claim:

1. In a truck of the class described, a pair of uprights on which a load member is mounted for lifting movement, scissors levers pivoted to a fixed part of the truck and to the uprights and stabilizing the uprights relatively to the truck, a hydraulic ram for actuating said scissors levers to move the uprights inwardly and outwardly relatively to the truck, a part of one of said scissors levers pivoted to a further part of said one lever, and a hydraulic ram for rotating said lever parts relatively to one an other whereby to tilt the uprights and load member relatively to the truck.

2. In a truck of the class described, a pair of uprights on which a load member is mounted for lifting movement, scissors levers extending between a fixed part of the truck and the uprights, means of connection through which said scissors levers stabilize the uprights relatively to the truck while leaving the uprights free for substantially. vertical movement relatively to the truck, bearing means supporting the uprights on the truck, and said means of connection enabling the truck to accept directly through said bearing means the weight of the scissors levers so that said uprights will not deflect under load while stabilizing the uprights.

3. In a truck of the class described, a pair of uprights on which a load member is mounted for lifting movement, scissors levers extending between a fixed part of the truck and the uprights and acting to stabilize the uprights relatively to the truck, a substantially horizontal link through which said scissors levers act and adapted to rotate so as to leave the uprights free for vertical movement relatively to the truck, bearing means supporting the uprights on the truck, and said link enabhng the truck to accept directly through said bearing means the weight of the uprights so that said uprights will not deflect under load.

4. In a truck of the class described, a pair of uprights on which a load member is mounted for lifting movement, a roller bearing supporting each uprighht for sliding movement on the truck and also for pivotal movement of the axis of the roller bearing, a series of levers connected independently of said bearings to the truck and to the uprights and stabilizing the uprights on said bearings means actuating the series of levers whereby to slide the uprights inwardly and outwardly relatively to the truck, a part of said levers movable independently of the actuation of the series of levers, and means for moving said part of the levers to tilt the uprights and load member relatively to the truck.

5. In a truck of the class described, a pair of uprights on which a load member is mounted for lifting movement, roller bearings arranged in a common axis and supporting said uprights for sliding movement on the truck, said uprights being adapted for pivotal movement on the common bearing axis, scissors levers extending between the truck and uprights and controlling pivoting of the uprights to stabilize said uprights on said bearing axis, means for rotating the scissors levers whereby to slide the uprights inwardly and outwardly relatively to the truck, a part of said levers rotatable independently of the rotation of the levers by said means, and means for rotating said part of the levers to tilt the uprights and load member relatively to the truck.

6. In a truck of the class described, a pair of uprights on which a load member is mounted for lifting movement, a pair of rails extending longitudinally on the truck, a pair of roller bearings arranged in a common axis on the uprights and engaged with said pair or" rails to support said uprights relatively to the truck, a pair of scissors levers extending between a fixed part of the truck and the uprights and stabilizing said uprights on said bearings relatively to the truck, a hydraulic ram for rotating the scissors levers to slide the uprights inwardly and outwardly on said rails relatively to the truck, a part of one of said levers pivoted to a further part of that lever, a hydraulic ram for rotating said lever parts relatively to one another to rotate the uprights on the common axis of their bearings whereby to tilt the uprights and load member, and a substantially horizontal link extending between the other of said pair of scissors levers and the uprights and allowing said uprights to have a substantially vertical movement relatively to said levers, whereby said levers need not accept the weight of the uprights and the truck will support the uprights through the bearings with substantially no deflection regardless of the positions to which the uprights slide and tilt relatively to the truck.

7. In a truck of the class described, a main frame, a pair of uprights, a load carriage mounted for lifting movement on said pair of uprights, means mounting said uprights for bodily sliding movement in a linear direction on said main frame, said mounting means being formed to permit pivotal bodily tilting movement of said uprights and load carriage relatively to said mounting means in substantially all linear positions of the uprights relatively to the truck, a leverage system connected independently of said upright mounting means to the main frame and to said uprights, means for actuating said leverage system in one manner to move said uprights and carriage linearly relatively to the truck, and means for actuating said leverage system in a different manner to tilt said uprights and load carriage while said uprights and carriage are supported through said mounting means relatively to the truck.

8. In a truck of the class described, a main frame, a pair of uprights, a load carriage mounted for lifting movement on said pair of uprights, means mounting said uprights for bodily sliding movement in a linear direction on said main frame, said mounting means being formed to permit pivotal bodily tilting movement of said uprights and load carriage relatively to said mounting means in substantially all linear positions of the uprights relatively to the truck, a leverage system connected independently of said upright mounting means to the main frame and to said uprights, means for moving levers in said system in a pivotal relation to each other to move said uprights linearly relatively to the truck, and means for moving said levers in a different pivotal relation to tilt the uprights and load carriage while said uprights and carriage are supported through said mounting means relatively to the truck.

9. In a truck of the class described, a main frame, a pair of uprights, a load carriage mounted for vertical lifting movement on said uprights, a roller mounted on a bottom portion of each upright and engaged with the main frame to mount said uprights for bodily sliding movement in a linear direction relatively to the truck, said rollers permitting said uprights and load carriage to pivot bodily in the roller axis so as to tilt relatively to the main frame in substantially all linear positions of the uprights relatively to the truck, a leverage system connected independently of said rollers to an upper portion of said main frame and to an upper portion of said uprights for stabilizing said uprights and holding them vertical in all of the linear positions of said uprights, means for actuating said leverage system to move said uprights and carriage linearly relatively to the truck, and means for changing the relation between portions of said leverage system to tilt the uprights and load carriage while said uprights are supported through their bottom rollers on the truck.

References Cited in the file of this patent UNITED STATES PATENTS 2,092,663 Bach Sept. 7, 1937 2,126,289 Schroeder Aug. 9, 1938 2,320,601 Howell -June 1, 1943 2,621,811 Lull Dec. 16, 1952 2,667,985 Woughter Feb. 2, 1954 2,752,058 Gibson a June 26, 1956 2,828,879 Arnot Apr. 1, 1958 2,975,923 Ulinski Mar. 21, 1961 2,998,891 Bauer et al. Sept. 5, 1961 3,013,011 Ackermann Jan. 23, 1962 3,031,091 Erickson et al. Apr. 24, 1962

Claims

1. IN A TRUCK OF THE CLASS DESCRIBED, A PAIR OF UPRIGHTS ON WHICH A LOAD MEMBER IS MOUNTED FOR LIFTING MOVEMENT, SCISSORS LEVERS PIVOTED TO A FIXED PART OF THE TRUCK AND TO THE UPRIGHTS AND STABILIZING THE UPRIGHTS RELATIVELY TO THE TRUCK, A HYDRAULIC RAM FOR ACTUATING SAID SCISSORS LEVERS TO MOVE THE UPRIGHTS INWARDLY AND OUTWARDLY RELATIVELY TO THE TRUCK, A PART OF ONE OF SAID SCISSORS LEVERS PIVOTED TO A FURTHER PART OF SAID ONE LEVER, AND A HYDRAULIC RAM FOR ROTATING SAID LEVER PARTS RELATIVELY TO ONE ANOTHER WHEREBY TO TILT THE UPRIGHTS AND LOAD MEMBER RELATIVELY TO THE TRUCK.