US3378159A

US3378159A - Upright mounting means for lift truck

Info

Publication number: US3378159A
Application number: US615844A
Authority: US
Inventors: George J Trusock
Original assignee: Clark Equipment Co
Current assignee: Doosan Bobcat North America Inc
Priority date: 1967-02-13
Filing date: 1967-02-13
Publication date: 1968-04-16
Anticipated expiration: 1985-04-16

Description

2 Sheets-Sheet 1 G. J. TRUSOCK April 16,1968

UPRIGHT MOUNTING MEANS FOR LIFT TRUCK Original Filed Sept. 12, 1962 INVENTOR GEORGE J. TRUSOCK ATTORNEY A ril 16, 1968 G. J. TRUSOCK UPRIGHT MOUNTING MEANS FOR LIFT TRUCK 2 Sheets-Sheet 2 Original Filed Sept. 12, 1962 ililm EIIITITIIWITITEE v INVENTOR GEORGE J. TRUSOCK BY a Mm ATTORNEY United States Patent 3,378,159 UPRIGHT MOUNTING MEANS FOR LIFT TRUCK George J. Trusock, Battle Creek, Mich., assignor to Clark Equipment Company, a corporation of Michigan Continuation of application Ser. No. 223,211, Sept. 12, 1962. This application Feb. 13, 1967, Ser. No. 615,844 Claims. (Cl. 214-672) This application is a continuation of United States application 223,211 filed Sept. 12, 1962, now abandoned.

This invention relates to industrial trucks used for transporting materials in workshops, factories and the like, and more particularly to a means for mounting the upright construction of such industrial trucks.

The invention is especially well adapted for use with lift trucks of the type disclosed in Patent No. 2,959,235, granted to D. H. Hubbard et al. on Nov. 8, 1960, wherein a tractor unit and a load carrying unit are coupled together and the elevator or upright mechanism of the lift truck is mounted in a location intermediate the ends of the truck. Because of the nature of the construction of such lift trucks it has been conventional heretofore to provide a non-tilting or fixed upright construction mounted at the inner end of the load carrying unit, and to sometimes provide for tilting of the fork carriage which is supported from the upright mechal'llSlTl.

It is a general object of my invention to provide improved mounting means for lift truck uprights.

In carrying out this object in a preferred embodiment of the invention I have provided in a lift truck of the above-stated type a pair of transversely spaced reversible mounting brackets or mounting means mounted adjacent the forward upper corner of each side of the tractor portion of the truck from which is pivotally mounted the upright construction. Actuating means are provided for pivoting the upright mechanism to a slightly tilted position out of a vertical plane about such pivotal mounting. The brackets or mounting means are reversible in position so that the pivotal connections to the upright are locatable in either of two positions longitudinally of the truck. In one mounting position, the upright may be pivoted to a rearwardly tilted position but not to a forwardly tilted position, and in the second mounted position the upright may be pivoted to either a rearward or forward position of tilt relative to a vertical position thereof.

In some lift truck applications it has been found unnecessary to provide for forward tilting of the upright, or at least not any significant degree thereof, and in such application my invention facilitates the use of an upright mounting construction with minimum loss of load center which is otherwise encountered in such lift trucks if there is provided a non-adjustable upright mounting which provides for both forward and rearward tilting movement thereof at all times, if at all. The upright mounting means of my invention may be reversed in position so as to shift forwardly the pivot means from which the upright is supported so that both forward and rearward tilting movement thereof is provided if required. This invention provides a distinct improvement in lift trucks of the type contemplated in that the operator may at his option, and with no change in the structure of the truck, multiply the effectiveness of the truck in load handling applications.

Another object of my invention is, therefore, to provide adjustable upright mouting means in lift trucks whereby the upright may assume different positions in a direction longitudinal of the truck.

A further and more specific object of the invention is to provide adjustable upright mounting means in lift trucks of the type contemplated which in different adjustment positions provides varying degrees of pivotal movement of the upright out of a vertical plane.

Other objects, features and advantages of my invention will become apparent to those skilled in the art from the following description when taken in conjunction with the drawings, wherein:

FIGURE 1 is a side elevational view of a lift truck which embodies a preferred construction of my invention;

FIGURE 2 is an enlarged broken-away plan view of the upright mechanism and mounting means therefor shown in- FIGURE 1;

FIGURE 3 is an enlarged partial side view in elevation showing the mounting means of the present invention in one position of adjustment; and

FIGURE 4 is similar to FIGURE 3 showing the mounting means for the upright mechanism in a second position of adjustment.

Referring now in detail to the drawings, there is illustrated an industrial truck having a power head or tractor unit 10 suitably coupled, as by welding, or if preferred by articulated means such as disclosed in the above-identified Hubbard et al. patent, to a load carrying unit or U-shaped frame 12-. Mounted from the connected ends of the traction and load carrying units is a pair of laterally spaced upstanding legs 14 from the upper ends of which is pivotally mounted an upright or elevator mechanism 16 in which is supported for elevating movement a load carriage and fork mechanism 18. The truck is supported by transversely spaced steering traction wheel 20 and caster wheel 22 located beneath an operators station of the traction unit 10, and by pairs of transversely spaced trail wheels 24 located at the forward end of each forwardly extending leg of the U- shaped load carrying frame 12.

Tractor unit 10 comprises generally a power head sec tion 26, including a suitable battery (not shown) located in a battery compartment 28, to drive the steering traction wheel 20, suitable pump and electric and hydraulic units, cables and hoses and the like, not shown, controlled by levers and 32 for driving wheel 20, for raising and lowering the fork and carriage assembly 18 in upright 16, and for tilting upright 16 by means of a hydraulic piston and cylinder assembly 34. An operators station is shown generally at numeral. 36 and includes in addition to control levers 30 and 32 a steering tiller 38 and braking mechanism, not shown.

The load carrying unit 12 comprises generally a pair of transversely spaced outrigger legs 40, one of which is shown, connected, as by welding to the bottom portion of the forward end of the frame of traction unit 10 by means of horizontally inwardly extending beams 42.

The upright construction 16 comprises generally a pair of laterally spaced outer fixed channel members 50, a

pair of laterally spaced I-beams 52 suitably nested within the channel members for vertical telescoping movement, and a hydraulic cylinder lifting motor 54, fork carriage assembly 18 being mounted in known .manner for vertical movement relative to members 52 and connected to hoist motor 54 by means of a pair of chain and sprocket mechanisms 56 which are anchored to the carriage at their one ends at numerals 58 and to the rear lower side of cylinder motor 54 at numeral 60. Transverse brace means 62 and 64 tie together the rear flanges of channel members 50, and brace means 66 ties together the rear flanges of I-beams 52 for rigidifying the mast structure. In order to clarify the structure in FIG. 2 brace means 62 is not shown. A pair of fork tines 68 are supported by bracket means 70 upon the transverse carriage plate 72 of carriage assembly 18. Pairs of vertically spaced

rollers

74 and 76 upport I-beams 52 in channel members 50 and carriage vssembly 18 in I-beams 52, respectively, for vertical movement of the carriage assembly and I-beams in the upight assembly upon actuation thereof by hoist motor 54 and chains 56. The mast construction 16 is disclosed n detail and claimed in copending US. continuation apilication Ser. No. 1110,070, filed May 18, 1961, in the names of Russell Hastings, J r. et al. (common assignee).

Except for prior references to the mast tilting mecha- Jism of the present invention, the structure described above is essentially conventional, and a more detailed ;howing and description thereof is not deemed to be necessary.

The upright mounting structure of the present invention includes a pair of transversely spaced bracket members 80 which are mountable atop the pair of upstanding body members 14 in either one of two positions of adjustment by four mounting bolts 82 which extend through horizontal corner portions of each bracket 80 and threadedly engage aligned openings in a horizontal plate member 84 which is secured to the upper end of each body member 14. A central raised portion 83 of each bracket member 80 has a transverse opening 89 formed therein for receiving a transversely extending pivot pin 90. The longitudinal axis of the opening 89 is off-set from the vertical axis of each bracket 80 so that when the brackets are mounted as shown in FIG. 3 the axes of pivot pins 90 are off-set rearwardly of the vertical central axes of the bracket members, and when located as illustrated in FIG. 4 the axes of the pivot pins are offset forwardly of the said axes of the brackets. A pair of block members 92 are secured to the outer surfaces of the web portions of channel members 50 of upright assembly 16 at a suitable elevation, each having an opening 94 extending therethrough which is adapted to receive an inner end of one of the pivot pins 90, whereby said pivot pins comprise the sole supporting structure of upright and

carriage assembly

16 and 18, said assembly in such mounted position on the truck being disposable in either one of the two locations thereof illustrated in the figures. Pivot pins 90 are preferably secured, as by welding, in openings 94, although they may, if desired, be similarly secured in brackets 80 or merely held in said brackets by detents or other pins.

The hydraulic cylinder means 34 comprises an extensible cylinder and piston assembly of well-known construction which extends centrally and horizontally of the truck, having its base end pivotally connected to the frame of the truck by a bracket 100 and the rod end 102 pivotally connected to a bracket 104 which is connected to and extends rearwardly of a transverse member 106 (FIG. 2) which is secured to the inner edges of the rearward flanges of channels 50 at the lower ends thereof. Extension and retraction of tilt cylinder 34 pivots upright and

carriage assembly

16 and 18 about pivot pins 90, as indicated by the broken lines in FIG. 1 forming the outline of the upright assembly in a rearwardly tilted position when cylinder assembly 34 has been extended.

It will be noted in FIG. 2 that with the upright in a vertical position and brackets 80 positioned as in FIG. 3 wherein the axis of pivot pins 90 is located rearwardly of the vertical axis of the brackets, a very small clearance 108 is present between the adjacent surfaces of transverse brace member 64 of the upright assembly and the forward vertical surface of traction unit such that the upright and carriage assembly can be pivoted to a rearwardly tilted position as desired within the limitation of extension of piston rod 102, but that the upright can be pivoted to an opposite or forwardly tilted position only an insignificant amount as determined by the above-mentioned clearance 108. If desired, the design of brackets 80 can be such as to provide a zero clearance at 198 so that with the upright assembly in a vertical plane, transverse brace member 64 abuts the forward surface of the body of traction unit 10, thereby providing no forward tilt, or even such that the upright assembly remains in a slightly rearwardly tilted position when brace member 64 abuts the forward body portion of the traction unit. This is, of course, a matter of choice of the designer, but I prefer to provide a very small clearance 108 as aforesaid. In applications of the lift truck which do not require any forward tilt of the upright and fork carriage assembly it will be appreciated by persons skilled in the art that the load carrying capacity of the truck is maximized as a result of the close longitudinal adjacency of the load supporting upright and carriage assembly relative to the traction unit, thereby minimizing the distance of the load center of gravity from the traction unit. This feature becomes particularly important in trucks of the type contemplated wherein a pantograph or other fork reaching mechanism, not shown, is frequently disposed between the upright assembly and fork tines in order to project the fork tines ahead of the truck for picking up a load, such as is illustrated in Quayle Patent No. 2,992,751.

In the provision of forward tilt of the upright and carriage assembly is important in certain applications of the lift truck, then by the simple maneuver of reversing the position of brackets from the FIG. 3 to the FIG. 4 location, by means of which the axes of pivot pins are relocated from a rearward to a forward position relative to the vertical axes of brackets 89, it will be apparent that the second mounting position of the upright and fork carriage assembly moves said assembly forwardly a distance equal to the movement of the axes of pivot pins 90 between the FIG. 3 and FIG. 4 positions thereof. Thus, additional and substantial clearance is provided between the forward body portion of tractor unit It and brace member 64- so that retraction of piston rod 102 in cylinder assembly 34 effects a forward tilting movement of the entire upright and fork carriage assembly about pivot pins 90 so that the tips of fork tines 68 can, for example, be wedged beneath floor supported loads. At the same time, piston rod 192 may be extended to effect a rearwardly tilted position of said assembly as shown in FIG. 1.

Thus, depending upon the desired application of the lift truck, the upright and fork carriage assembly may be pivotally mounted in alternate positions relative to the traction unit either for minimizing the distance of the center of gravity of a load carried by fork times 63 from traction unit 10 with little or no available forward tilt of the said assembly, or for increasing said distance of the center of gravity from the traction unit while providing a significant degree of forward tilt of the upright and fork carriage assembly. The present invention, therefore, increases the versatility of lift trucks of the type contemplated to a significant degree with no change in structural components beyond the mere relocation of readily accessible bracket members 80 supporting the upright carriage assembly.

Wherein the various parts of my invention have been referred to as located in a forward or rearward, or an inward or outward position, and the like, it will be understood that this is done solely for the purpose of facilitating description and that such references relate only to the relative positions of the parts as shown in the drawings.

Although only one embodiment of my invention has been illustrated and described, it will be apparent to those skilled in the art that various changes in the structure and relative arrangement of parts may be made to suit individual requirements Without departing from the scope of the invention which is defined and comprehended solely by the appended claims which should be construed as broadly as the prior art will permit.

I claim:

1. In an industrial truck having a load-lifting upright mechanism supported pivotally thereon to extend vertically adjacent a portion of the truck the improvement comprising support means fixed on the truck and mounting means for pivotally support-ing the upright mechanism defining a pivot axis, said mounting means fixed on said support means selectively in only one of two alternative adjusted positions disposing said pivot axis in a corresponding one of two locations each lying in one of two vertical planes spaced longitudinally of the truck at different intervals relative to portions of the truck, said mounting means when in either of said position occupying substantially the same location on said support means.

2. The improvement in an industrial truck defined in claim 1, in which said support means comprises a pair of transversely spaced support members, said mounting means comprising a pair of mounting elements each fixed on one of said support members selectively in one of said two positions, said mounting elements including means pivotally connected to opposite side portions of the upright mechanism to define said pivot axis therefor and so related to the remainder of said mounting elements as to dispose said axis in one of said locations in accordance with the selected fixed position of the mounting elements.

3. An industrial truck as defined in claim 2, in which each of said mounting elements comprises a bracket having an axis about which it may be rotated to dispose opposite ends longitudinally rearwardly, and means on said bracket defining a horizontal pivot axis offset from said rotational axis for disposition forwardly or rearwardly thereof in accordance with the rotated position of the bracket, the rotational axis 'being disposed in a predetermined position longitudinally of the truck in both said positions.

4. The improvement in an industrial truck defined in claim -1, in which said body portion is located adjacen one end of the truck, said support means comprising pair of transversely spaced upstanding leg members ad jacent said one end with the upright mechanism there between, said mounting means being fixable on said leg members and including pivot means supporting the up right mechanism therefrom, said leg members and mountvertical axis thereof, the vertical axis being disposed in a predetermined position longitudinally of the truck in both said positions.

References Cited UNITED STATES PATENTS 3,014,344 12/1961 Arnot 214--674 3,151,755 10/1964 Quayle 214-67O FOREIGN PATENTS 1,047,719 12/1958 Germany.

GERALD M. FORLENZA, Primary Examiner. R. B. JOHNSON, Assistant Examiner.

Claims

1. IN AN INDUSTRIAL TRUCK HAVING A LOAD-LIFTING UPRIGHT MECHANISM SUPPORTED PIVOTALLY THEREON TO EXTEND VERTICALLY ADJACENT A PORTION OF THE TRUCK THE IMPROVEMENT COMPRISING SUPPORT MEANS FIXED ON THE TRUCK AND MOUNTING MEANS FOR PIVOTALLY SUPPORTING THE UPRIGHT MECHANISM DEFINING A PIVOT AXIS, SAID MOUNTING MEANS FIXED ON SAID SUPPORT MEANS SELECTIVELY IN ONLY ONE OF TWO ALTERNATIVE ADJUSTED POSITIONS DISPOSING SAID PIVOT AXIS IN A CORRESPONDING ONE OF TWO LOCATIONS EACH LYING IN ONE OF TWO VERTICAL PLANES SPACED LONGITUDINALLY OF THE TRUCK AT DIFFERENT INTERVALS RELATIVE TO PORTIONS OF THE TRUCK, SAID MOUNTING MEANS WHEN IN EITHER OF SAID POSITION OCCUPYING SUBSTANTIALLY THE SAME LOCATION ON SAID SUPPORT MEANS.