US3529739A - Lift truck with a mast mounted on a wheeled horizontal and vertically pivoted support - Google Patents

Description

3,529,739 LIFT TRUCK WITH A MAST MOUNTED ON A WHEELED HORIZONTAL Sept. 22, 1970 w. M. SHAFFER AND VERTICALLY PIVOTED SUPPORT 5 Sheets-Sheet 1 Filed April 12, 1958 INVENTOR- WALTER M- SHAFFER ATTORNEYS 3,529,739 ZONTAL W. M. SHAFFER Sept. 22, 1970 LIFT TRUCK WITH A MAST MOUNThD ON A WHEELED HORI AND VERTICALLY PIVOTED SUPPORT Y 5 Sheets-Sheet 2 Filed April 12, 1968 INVENTOR. WALTER M. SHAFFER 54, PW -I ATTORNEYS p 1970 w. M. SHAFFER ,739

LIFT TRUCK WITH A MAST MQUNTED ON A WHEELED HORIZONTAL AND VERTICALLY PIVOTED SUPPORT Filed April 12,1968 5 Sheets-Sheet 3 v INVENTOR, WALTER M. SHAFFER v .w. M. SHAFF'ER 3,529,739 LIFT TRUCK WITH A MAST MOUNTTLDON A WHEELED HORIZONTAL Sept. 22, 1970 AND VERTICALLY FIVOTEDY SUPPORT v 5 Sheets-Sheet 4.

Filed April 12. 1968 "IINVENTOR. WAUER M. SHAFFER ATTORNEYS Sept. 22, 1970 w FER 3,529,739

LIFT TRUCK WITH A MAST MOUNTED ON A WHEELED HORIZONTAL AND VERTICALLY PIVQTED SUPPORT Filed April 12, 1968 5 Sheets-Sheet 5 INVENTOR. WALTER M. SHAFFER BY 9 W4 w, RM4Q+M ATTORNEYS United States Patent Int. Cl. B65g 47/00 US. Cl. 214-672 4 Claims ABSTRACT OF THE DISCLOSURE Stacks or bundles of elongated materials, such as pipe or lumber, in lengths in excess of eight feet are very difficult to handle with an ordinary lift truck in confined dunnage spaces. A lift truck capable of handling such materials in confined dunnage areas includes a steerable truck unit having individually powered wheels and a narrow, long boom assembly pivoted at one end on the truck unit and supported at its opposite end by an outtrigger wheel unit, said boom assembly being swingable about its pivot relative to the truck unit about a generally vertical axis and having a conventional mast, hoist cylinder, carriage and lift forks centrally disposed on the boom assembly with the forks projecting normally from the boom assembly. This arrangement allows such elongated stacks of material to be handled with their longitudinal axis parallel to the boom assembly and further allows the boom assembly to be oriented so that it can be generally aligned with the direction of travel for movement through confined aisles and the like.

BACKGROUND OF THE INVENTION Conventional lift trucks handling pallets of lumber, pipe or other material having lengths in excess of eight feet require wide aisles and considerable maneuvering room since these materials will be generally orientated perpendicular to the direction of travel of the vehicle. Some reduction in maneuvering room can be effected if the front portion of the truck carrying the mast, hoist cylinder, carriage and lift forks is pivoted, as shown in US. Pat. No. 3,039,638 issued to Shaffer, or if the mast, hoist cylinder, carriage and lift forks are pivoted as a unit on the front of the truck, as shown in US. Pat. No. 3,335,879, also issued to Shaffer.

However, the above machines still are not completely satisfactory for special applications such as loading pallets of elongated materials in boxcars or manipulating them in similar confined areas.

For example, a serious problem arises when attempting to utilize a conventional lift truck to handle elongated material in boxcars since the current door opening is only about six feet. Stacks of lumber or other elongated material having individual components exceeding six feet in length normally have to be manually loaded in boxcars since conventional lift trucks cannot be employed due to the confined opening and limited space within the boxcars. Obviously, such hand handling procedures are both costly and time consuming.

Employing the present invention, such elongated loads can be easily handled in an opening slightly larger than Patented Sept. 22, 1970 "Ice that necessary to accommodate the width of the novel lift truck. In addition, such loads can even be manipulated into limited spaces inadequate to accommodate the body of the lift truck itself, by employing special boom orientations. Such features are particularly useful in loading boxcars and the like.

SUMMARY OF THE INVENTION A novel industrial lift truck which provides the outstanding features noted above comprises a box-like truck unit having a power unit and dirigible wheels, a narrow boom assembly having its inboard end swingably mounted about a vertical axis adjacent to a corner of said frame and its outboard end supported by an outrigger wheel whereby said boom may be positioned relative to the truck unit, said boom including a telescoping mast, hoist cylinders, a carriage and lift forks projecting normally to the boom assembly so elongated materials will be oriented lengthwise of the boom when supported by the forks. Also, increased clearance can be achieved by using lift forks which are retractable or collapsible.

BRIEF DESCRIPTION OF THE DRAWINGS The full construction and operation of the new lift truck will be better understood by reference to its description in conjunction with the following drawings wherein:

FIG. 1 is an elevation of the novel lift truck;

FIG. 2 is another elevation of the lift truck with a load supported on its lift forks and with broken lines indicating an alternate position of the forks;

FIG. 3 is a top view of the lift truck with the boom assembly in a stowed position and with broken lines indicating the retracted positions of the lift forks;

FIG. 4 is a view similar to that shown in FIG. 3, but with the boom assembly positioned differently relative to the truck unit;

FIGS. 5-7 are diagrammatic top views showing the manipulation of elongated loads in a boxcar with the novel lift truck; and

FIGS. 8l0 are diagrammatic end views of a stacking operation of elongated loads in boxcars with a novel lift truck.

DESCRIPTION OF A PREFERRED EMBODIMENT As can be seen in FIG. 1, the novel lift truck 10 is composed of a steerable truck unit 11 on which a boom assembly 12 is swingably mounted at one end and supported at the other end by an outrigger wheel unit 13.

The truck unit 11 includes a box-like body 14, which is supported by steerable or dirigible Wheel units 15 and 16. Each dirigible wheel unit is hydrostatically or electrically powered so it can drive the truck unit in opposite directions, regardless of their angular position relative to the body. Wheel unit 15 supports the body under the corher where the boom assembly is pivoted, while the other wheel unit is centrally located along the side of the body remote to the boom assembly, as can be seen in FIGS. l-3.

Each of the wheel units 15 and 16 are steerable by the operator from platform 20 through a separate control 21 and outrigger wheel unit 13 which supports the outer end of the boom assembly is slaved to steer with wheel unit 15 and is either electrically or hydraulically powered, as are the wheel units connected to the body.

Power is supplied to the wheel units through wires or hydraulic lines from the power units (not shown) in the body of the truck unit, and it can be appreciated that the three wheel units can be orientated and powered to cause the vehicle to travel in any desired direction.

The unique boom assembly 12 is connected to the truck unit through a vertical pivot pin directly above wheel unit 15 so its cantilevered or bridge section 31 will extend across the top of the truck unit to clevis connection 32, adjacent to which it joins the main portion of the boom assembly, the mast assembly 33. The outboard end of the mast assembly is supported by outrigger wheel unit 13 which includes a vertical adjustment cylinder and slide 34 to change the height of the outboard end of the boom, as the operator desires.

With the cantilevered section and the mast section joined in aligned relationship, the boom assembly forms an elongated structure of a narrow Width, as can be seen in FIGS. 1-4. More particularly, the bifurcated end 35 of the cantilevered section is journaled on opposite ends of upright pivot pin 30 which is in turn connected to the truck unit by horizontal pin 36 of pivot joint 37 formed by a pair of vertical plates 38 joined to the top and projecting over the side of the body. Horizontal pin 36 is axially aligned with pin 39 of the clevis connection 32 so that when the latter pin is in the clevis connection the boom assembly can tilt about the aligned axis of these pins.

To hold the boom from tilting about these pins, a hydraulic jack 40 is connected between fixed lugs 41 on the top of the truck unit and lugs 42 near the top of the upright pivot pin 30. Extension of this jack will tilt the top of the boom away from the truck or toward the truck when it is retracted. Tilt limits for the top of the boom are 5 away from the truck unit and 20 toward it, using a vertical reference.

With pin 39 removed from the clevis connection 32, the truck unit can be maneuvered relative to boom assembly, as the boom assembly turns on upright pivot pin 30 to a large number of intermediate positions. FIG. 4 shows the boom assembly swung 180 relative to the truck unit and in this position or others, the brake and lock units 45 operated by lever 46 can be employed to prevent fur ther relative movement. These latter assemblies are best seen in FIG. 2.

On the mast section 33 of the boom assembly is a vertical orientated quadruple mast 50 which is raised and lowered by hoist cylinders 51. A lift carriage 52 is cooperatively engaged with the mast and is raised and lowered, in a conventional manner. The quadruple mast allows the over-all height of the boom assembly 13 to be minimized.

Lift forks 53 are connected to the carriage through pivoted connections 54 and normally positioned to project normally from the boom for supporting a load, being positioned by jacks 55. Since the lift carriage is oriented parallel to the longitudinal axis of the boom, jacks 55 may be employed to slew the lift forks in line with the boom to decrease the space necessary for maneuvering the boom in an unloaded condition. Broken lines 5311 in FIG. 3 show the forks in a fared position.

In FIG. 2, collar units 56 in which the lift forks are pivoted, can be seen as well as their connection to the lift carriage 52 with horizontal pins 57. A jack 58 is connected between each collar and an adjacent portion of the lift carriage, which can be used to raise or lower the outboard ends of the forks. By actuation of jacks 58, the forks can be swung upwardly to a vertical position as indicated by broken lines 59 in FIG. 2 when the carriage is at the top of the boom assembly.

Also located on the mast section near the bottom of the boom assembly is a retractable outrigger arm 60 hinged with pin 61 at the bottom of a vertical pivot post 62 which is journaled in spaced lug members 63 on the mast section. Near the upper end of the pivot post, a jack 64 is connected between it and the mast section so that its actuation will rotate the post and slew the outrigger arm to any position from parallel wih the boom to a position normal to the boom. The vertical position of the outboard end of the outrigger arm, which contains a small diameter roller 65, is controlled by a jack 66 connected between the inboard end of the arm and the center of the vertical post.

The outrigger arm, which is of a thin construction, can be used in the dunnage spaces beneath pallets to stabilize the boom when heavy loads are supported on the lift forks or certain boom-fork configurations are being employed which adversely affect the balance of the entire unit.

Through the unique construction of the instant lift truck, a large number of configurations may be employed at the operators option which will enable handling operation which otherwise would be impossible with lift trucks in confined dunnage areas.

OPERATION OF LIFT TRUCK FIGS. 5-10 illustrate the unique ability of the novel lift truck to handle elongated materials in very confined dunnage spaces. A boxcar loading sequence is employed for the purpose of detailed handling operations.

Generally, elongated loads L are supported on the lift forks in the sequence and in FIG. 5, the lift truck is entering boxcar 70 through its six foot door opening 71 with the load raised sufficiently to clear pallets 72 already positioned in the boxcar. Normally, the lift truck will be in the configuration illustrated in FIG. 3 unless a variation is necessary to accommodate the dunnage space situation.

FIG. 6 shows a raised load being moved down a narrow aisle for positioning it on top of the pallet 72 and with broken lines 73 illustrating the configuration of the truck unit which allows final positioning of the load.

In FIG. 7, the load is being placed on top of an adjacent load. End views 8-10 show how the load and boom may be manipulated with this novel truck to fully load a boxcar.

A further explanation should not be necessary to those skilled in the art, as to the numerous configurations, flexibility and operation of the instant invention.

What is claimed is:

1. A lift truck for handling elongated loads comprismg:

a truck having at least two spaced-apart powered dirigible wheels;

a vertical pivot post having its lower end connected to said truck unit through a horizontal pivot means;

an actuator connected to the upper portion of said vertical pivot post whereby said upper portion of said vertical pivot post can be oscillated by said actuator about said horizontal pivot means;

a narrow elongated frame having one end journalled on said vertical pivot post whereby said truck unit and said elongated frame can be articulated relative to one another;

a powered dirigible wheel connected to the opposite end of said elongated frame assembly for supporting that end of said elongated frame assembly and said lift truck through said elongated frame assembly;

a vertically telescoping mast means centrally mounted on said elongated frame assembly; and

load lift means connected to said mast whereby elongated loads can be supported thereon parallel to the longitudinal axis of said elongated frame assembly and said truck unit can be articulated about its connection to said elongated frame assembly for achieving maximum clearances and maneuverability.

2. The lift truck as defined in claim 1 wherein the load lift means connected to the mast means includes a carriage connected to said mast means, retractable lift forks pivoted on such carriage, and tilt means connected to said lift forks for swinging the outboard ends of said lift forks upwardly and downwardly.

3. The lift truck as defined in claim 1 wherein one of the dirigible wheels of the truck unit is located adjacent to an edge of said truck unit and the vertical pivot post is connected to said truck unit above said one powered dirigible wheel to provide maximum stability and to facilitate articulation of said truck unit relative to said elongated frame assembly.

4. The lift truck as defined in claim 1 wherein the powered dirigible wheel supporting the outboard end of the frame assembly includes vertical slide means to adjust said powered dirigible wheel vertically relative to its connection to said elongated frame assembly.

References Cited UNITED STATES PATENTS 2,618,396 11/1952 Belt 214-671 6 2,753,066 7/ 1956 Arnol 214-671 2,773,614 12/ 1956 Edwards et al. 214-671 XR 3,107,803 10/1963 Glosup et al 214-520 3,225,949 12/1965 Erickson et al. 214-660 5 3,382,994 5/ 1968 Hollenbach 214-671 FOREIGN PATENTS 946,691 1/ 1964 Great Britain. 990,992 5/ 1965 Great Britain.

US. Cl. X.R.

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