US2788863A - Lift truck - Google Patents

Description

B. I. ULlNSKl Ann-il' 16, 1957 LIFT TRUCK 5 Sheets-Sheet 1 Filed April 3, 1955 9M ATTORNEY B. L ULlNSKl prl 16, 1957 LIFT TRUCK 5 Sheets-Sheet 2 Filed April 3, 1953 ATTORNEY April 16, 1957 B. l. ULxNsKl 2,788,863

LIFT TRUCK Filed April 3; 1955 5 sheets-sheets INVENTOR ATTORNEY April 15, 1957 `B. l. uLlNsKl 2,788,863

` LIFT TRUCK Filed April 3, 19527 5 Sheets-Sheet 4 0 o n o o o o o o o o a o INVENTOR (AJ/br 'i7' ATTORNEY April 16, 1957 Fle'd April 3, 1955 B. l. uLmsKl 2,788,863

LIFT TRUCK 5 Sheets-Sheet 5 Z-Z INVENTOR El; /flw l' A'ToRNEY nted States Patent F LIFT TRUCK Bronislaus I. Ulinski, Chicago, Ill.,v assignor to The Yale & Towne Manufacturing Company, Stamford, Conn., a corporation of Connecticut Application April 3, 1953, Serial No. 346,603

2 Claims. (Cl. IS7-9) This invention relates to industrial lift trucks of that class in which a load lifting carriage moves vertically on secondary uprights, with these uprights in turn moving vertically on primary uprights. My invention relates especially to the truck of this class that is shown in my Patent No. 2,554,930- and it is the particular object of my invention to shorten this truck.

In the construction shownv in my patent, I utilize one hydraulic ram for lifting the load carriage relatively to the secondary uprights, and a second ramv to lift the secondary uprights relatively to the primary uprights. The rams operate in sequence so that the carriage can be fully lifted relatively to the secondary uprightsbefore the secondary uprights are lifted relatively to the primary uprights. Those skilled in the art will fully appreciate the value of the contribution to the art of my patented structure.

Because my patented construction usesitwo rams spaced relatively to one another in a direction lengthwise on the truck, it naturallyV increases the length of the truck, and attempts have already been made to contribute other constructions whereby to shorten this truck. In the patent to Schroeder, No. 2,505,609, the rams are telescoped and the secondary uprights are placed in alignment with the primary uprights in a direction transverse to the truck. This arrangement reduces the length of the truck and is very effective. However, the Schroeder two ram esserti-bly must be specially made for the particular purpose and is rather costly as compared to the two simple standard rams of my earlier patent. A further attempt to solve the problem was contributed by Quayle in Patent No. 2,518,251, but Quayle also requires a costly telescopic ram assembly.

ln the truck shown in this application there is a ram for lifting the secondary uprights relatively to the primary uprights and a second ram for lifting the load carriage relatively to the secondary uprights, the general arrangement being that contributed to the art in my Patent No. 2,554,930 supra. As a feature of my invention, the rams are mounted in offset relation to one another, both sidewise and lengthwise of the truck so that a line connecting the axes of the rams-in plan view actually lies diagonaliy relatively to both the length and breadth of the truck. Through this arrangement, the two rams do not occupy that space lengthwise or breadthwise of the truck that would be occupied by rams arranged in a conventional manner, all as those skilled in the art will readily appreciate.

As a still further feature of my invention, the rams, as in my patent, are adapted to lift the secondary uprights and the carriage through ilexible members, such as chains that are actuated through sheaves carried by the rams, it being the particular feature of my invention to mount the sheaves in a position lying diagonally relatively to the length and breadth of the truck, whereby to make possible the application of the lifting force to central points on the load carriage and the secondary uprights. Of course, the arrangement has the further Patented Apr'.4 16,V 1957 advantage in that the chains will not lie in a position to obstruct the View of the operator of the truck while, at the same time, the chains will not occupy substantial space lengthwise of the truck.

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. lt 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. l is a side view showing a preferred form of my invention.

Fig. 2 is a front View of the construction shown in Fig. 1.

Fig. 3 is a cross-sectional plan view.

Figs. 4, 5, and 6 are sections taken on the correspondly numbered`lines in Fig. 3.

Fig. 7 is a plan View showing the arrangement of the chains relatively to the rams.

Fig. 8` is a front View of parts shown in Fig. 7.

1Figs. 9, l0, and 1I are diagrammatic views illustrating the lifting movements of the rams and the uprights.

Referring more particularly to the drawings, I show an industrial truck 10 upon which a pair of transversely spaced primary uprights 11 are mounted through brackets 12, as may be seen in Figs. 1, 3 and 5. Secondary uprights 13 are mounted for vertical movement relatively to the primary uprights 11 through rollers 15, and a load carriage 14 is mounted for vertical movement reiatively to the secondary uprights 13 through rollers 16, as will be understood by those skilled in the art. It is important to note that l mount the secondary uprights 13 substantially in alignment with the primary uprights 11 in a direction transverse to the truck, thereby shortening the truck. This construction in itself is quite similar to that shown in the Schroeder patent referred to above. Nevertheless, my invention enables me to utilize this construction to particular advantage because of the extremely novel features that l shall describe in detail.

As will be seen perhaps the most clearly in Figs. 9, l0 and ll, I utilize a vertical hydraulic ram 17 for lifting the secondary uprights 13 relatively to the primary uprights 11, and a second vertical hydraulic ram 1S for lifting the load carriage 14 relatively to the secondary uprights 13. The rams 17 and 18 are the counterparts of the rams shown in my earlier patent but, in the novel construction that l have now conceived, l mount these rams in overlapping positions that are oifset in a direction transverse to the longitudinal axis of the truck. l mount the ram 17 relatively to the primary uprights 11, and for this purpose I prefer to utilize a horizontal support plate 19 that is positioned actually between the uprights and to the left of the truck axis, as viewed in Figs. 3 and 4. In the particular-construction that l have shown, l Secure the support plate 19 to a transverse member 20 on the primary uprights 11, and l further brace the plate 19 through a vertical member 21 that is supported by a member 22 on the lower ends of the uprights 11.

I mount the ram 18 relatively to the secondary uprights 13 in a position that is offset relatively to the ram 17 and between the uprights, this ram being at the right hand side of the truck axis as viewed in Figs. 3 and 4. I prefer to utilize for this purpose mounting means that is similar to the mounting means for the ram 17, including a horizontal support plate 23 vthat is mounted upon the secondary uprights 13 through a transverse member 24, and arvertical brace member 25 that is supported by a member 26 on the uprights 13. It is well to note at this point that the support plates 19 and 23 overlap in a longitudinal direction on the truck, and can move freelyrrelatively to each other in a vertical direction. Also, the support plates 19 and 23 are spaced inwardly somewhat from the secondary uprights 13, as may be seen clearly in Figs. 3 and 4, to allow free vertical movement of parts 27 through which the load carriage 14 is mounted on these uprights. In the construction that I have described, the rams 17, 18 and the uprights 11'and 13 occupy a minimum amount of space on the truck because they are substantially in alignment in a direction transverse to the v truck. I am enabled, moreover, to utilize duplicate rams of a standard construction, although I do not so limit my invention. Conceivably, of course, the rams could be mounted in this arrangement through means having other specific details.

In the particular construction that I have chosen to illustrate, I have shown a pair of chains 28 with which the ram 17 coacts through a sheave 29 to lift the secondary uprights 13 relatively to the primary uprights 11. The chains 28 are attached at one end to the support plate 19 and at the opposed endto the support plate 23 through rods 30, so that functionally these chains extend between the primary uprights 11 and the secondary uprights 13, as will be understood by those skilled in the art. The actual form of the chains 2S is not important to an understanding of my invention, and these chains could be a single chain or other exible member to serve the particular purpose.

In my invention, however, I do arrange the sheave 29 and the exible member or chains 28 in an exceedingly novel way. Thus, I mount the sheave 29 on the piston of the ram 17 to `rotate on a horizontal axis that is at an angle to the longitudinal axis of the truck, with the chains 28 extending over the sheave 29 in an angular direction. The chains 28 thereby extend vertically downwardly from the sheave 29 at opposed sides of the ram 17V in positions that are actu-ally between the secondary uprights 13. In this construction, moreover, I attach the lifting ends of the chains 28 to the secondary uprights substantially centrally of the uprights as will be apparent in Fig. 3. I thereby enable the ram 17, despite its position and the position of the chains 28, to lift the secondary uprights 13 through a force that is balanced relatively to these uprights.

To lift the load carriage 14 relatively to the secondary uprights 13, the ram 18 acts through chains 31 that are attached at one end to the support plate 23, and at the opposed end to the carriage 14 through -a bracket 32, this bracket being positioned substantially equidistant from the rollers 16 that support the carriage on the secondary uprights. The chains 31 extend over an angularly disposed sheave 33 on the piston of the ram 18, and because of their arrangement lift the load carriage 14 through a force that is balanced relatively to the carriage. This arrangement is like that already described in connection with the chains 28 and sheave 29. It is thought unnecessary, therefore, to describe this feature in further detail. v

I believe that those skilled in the art will now understandthat I have very successfully shortened the truck disclosed in my earlier patent, and that I have accomplished this while retaining the very desirable features shown in my patent. The very considerable merit of my novel contribution will therefore be apparent' I now claim:

l. A lift truck of the class described comprising a pair of primary uprights spaced relatively to one another in a direction transverse to the truck, a pair of secondary uprights mounted for vertical'movement on said primary uprights, a load carriage mounted for vertical movement on said secondary uprights, a rst hydraulic ram, means mounting said first hydraulic ram in arposition secured relatively to the primary uprights, a secondary hydraulic ram, means mounting said second hydraulic ram in a position secured relatively to the secondary uprights, the rams being positioned in offset relation sidewise and lengthwise of the truck and with their axes on opposite sides of the longitudinal center line of the uprights so that a line connecting said axes of said rams in plan view will lie diagonally relatively to the length and breadth of vthe truck, a sheave carried by the movable portion of each ram, said sheaves in plan view lying diagonally relatively to the length and breadth of the truck, a rst exible member connected to the primary uprights and the secondary uprights and passing over the sheave of the first ram, a second exible member connected to the secondary uprights and to the load carriage and passing over the sheave of the second ram, the rams being operatcd by uid means to elevate thc secondary uprights and the load carriage through said exible members.

2. A lift truck of the class described comprising a pair or" primary uprights spaced relatively to one another in a direction Atransverse to the truck, a pair of secondary uprights mounted for vertical movement on said primary uprights, a load carriage mounted for vertical movement on said secondary uprights, a first hydraulic ram comprising relatively extendible cylinder and piston parts, means securing one of said parts Vin fixed relation to the primary uprights, a second hydraulic ram also comprising relatively extendible cylinder and piston parts, means securing one of said parts in fixed relation to the secondary uprights, the rams being positioned with their axes on opposite sides of the longitudinal center line of the uprights and with the peripheries of the cylinder parts thereof in overlapping relation lengthwise and sidewise of the truck so that a line in plan view connecting said axes of said rams will lie diagonally relatively to the length and breadth of the truck, a sheave carried by the movable part of each ram, said sheaves in plan view lying diagonally relatively to the length and breadth of the truck, a first exible member connected to the primary uprights and the secondary uprights and passing over the sheave of the rst ram, a second exible member Yconnected to the secondary uprights and to the load carriage and passing over the sheave of the second ram, the rams being operated by fluid means to elevate the secondary uprights and the load carriage through said; tiexible members.

References Cited in the tile of this patent UNITED STATES PATENTS

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