US3703969A - Process of placing a head in a space with a lift truck - Google Patents

Abstract

A narrow-aisle lift truck with a wheelbase which can be varied by hydraulic cylinders operable to extend and retract movable arms upon which are mounted non-steerable wheels.

Description

United States Patent 1 11 1 3,703,969

Shaffer et al. C 1 Nov. 28, 1972 [54] PROCESS OF PLACING A HEAD IN A SPACE WITH A LIFI TRUCK [56] References Cited [72] Inventors: Walter ,M. Shaffer, Chester-land; UNITED STATES PATENTS John T. Crawford, Lyndhurst, be of Ohio 2,320,601 6/1943 Howell ..214/674 2,859,890 11/1958 Renard ..214/670 Asslgnee= Towmotor p i Cleveland, 3,098,574 7/1963 De Marco ..214/674 Ohio 3,565,273 2/1971 Hahn ..2l4/674 2 F 21 97 lled June 1 1 Primary Examiner-Gerald M. Forlenza pp 155,322 Assistant Examiner-K Johnson Related Us. Application Data Attorney-Fryer, T ensvold, Fe1x, Ph1ll1ps & Lemp1o [62] Division of Ser. NO. 822,843, April 14, 1969, ABSTRACT Pat. No. 3,616,953.

be varied by hydraulic cylinders operable to extend 521 US. Cl ..214/1s2, 214/672 and retract movable m u pon whlch are mounted 51 161. C1 ..B66f 9/20, 365g 1/04 nomsteemble wheels 58] Field of Search ..214/152, 16 B, 16.4 A, 730,

214/660, 670-674; 280/34 4 Claims, 7 Drawing figures A narrow-aisle lift truck with a wheelbase which can PATENTEDnuvza 1912 sum 1 or 4 INVENTORS WATER M. SHAFFER JOHN T. CRAW FORD PATENTED NOV 2 8 1912 SHEET 2 BF 4 INVENTORS WALTER M. SHAFFER JOHN T. CRAWFORD ATTORNEYS PATENTEDnnvzs I972 SHEET & 0F 4 INVENTORS WALTER M. SHAFFER JOHN T. CRAWFORD This is a division of application Ser. No. 822,843, I

filed on Apr. 14, 1969, now U.S. Pat. No. 3,616,953 granted Nov. 2, 1971.

BACKGROUND AND SUMMARY OF THE INVENTION reason, many attempts have been made in'recent years to produce lift trucks which could operate in the narrowest possible space so as to minimize the floor space in a warehouse which must be devoted to aisles.

Other types of existing narrow-aisle trucks include straddle-base trucks with front outrigger members having such dimensions to permit straddling the load to be picked up, and trucks containing a pantograph mechanism for reaching beyond the forward outrigger wheels to engage the load. When aisle width is not critical, a counterbalanced truck is normally used, wherein the front of the mast is always located ahead of the front wheels, and counterbalancing weight is applied behind the front wheels for stability. I

The subject invention readily fulfillsthe requirement of operating in the narrowest possible aisle space with the stability of a counterbalanced truck andwithout the disadvantages of the existing narrow-aisle trucks. For

example, reach mechanisms have visibility limitationsand high maintenance costs; both reach trucks and straddle trucks have exposed operator compartments which constitute a safety hazard and, in addition, have poor accessibility to the electric storagebattery.

The subject invention accomplishes the sought-after requirement by providing a variable wheelbase which may be changed for any given size load. The wheelbase is varied by means of hydraulically extending and retracting two of the vehicle wheels along the longitudinal axis of the vehicle. Additionally, the provision of an extended wheelbase produces improved stability when transporting loads.

Thus, it is an object of this invention to provide a lift truck which increases warehouse versatility, safety and capacity.

It is also an object of this invention to provide a lift truck capable of operating in a narrower aisle than heretofore possible while providing counterbalanced truck advantages.

It is also an object of this invention to provide such a lift truck having a variable wheelbase which provides stability and versatility equal to that of machines having longer wheelbases, but which must operate from much wider aisles.

It is a further object of this invention to provide a lift truck having a variable wheelbase, allowing optimum side angle stacking in narrower aisles than with those trucks presently available.

It is a still further object of this invention to provide a variable wheelbase lift truck which permits a long wheelbase during normal operation of the vehicle,

there by providing proper location and protection of the driver and the battery compartment.

It is a still further object of this invention to provide a lift truck which eliminates the well-known reach mechanism which has many .moving parts, thereby decreasing maintenance costs.

It is also an object of this invention to provide a lift truck having a turning radius which is much smaller than those of counterbalanced lift trucks presently available.

Other objects and advantages of the present invention will become apparent from the following description and claims as illustrated in the accompanying drawing which, by way of illustration shows a preferred embodiment of the present invention and principles thereof and what is now considered to be the best mode contemplated for applying these principles. It is recognized that other embodiments of the invention utilizing the same or equivalent principles may be used, and structural changes may be made as desired by those skilled in the art, without departing from the present invention and purview of the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS.

bodying the present invention, and the manner in which it is used to place a loadv in position.

DETAILEDYDESCRIPTION Referring now to FIGS. 1-3 in greater detail, there is shown a lift truck IO-having an operators compartment 12, to the rear of which is a large compartment 14 which containsthe vehicle batteries and motor or an engine. I

A pair of steerable drivezwheels 18 are mounted on the vehicle below the compartment 14, the wheels being steerable by any well-known mechanism (not shown). 7 I

On the forward portion of the vehicle, a mast pivot support 20 carries a mast 22 which is pivotable about bearings 24. Also on the forward portion of the vehicle, a side-shifter carriage 28 carries a pair of load forks 30.

A pair of nonsteerable load wheels 32 are mounted on movable arms 34 which are of a channel cross-section. As clearly shown in FIGS. 1 and 2, the nonsteerable load wheels are in the extended position. When retracted, the axes of the wheels are withdrawn to the left until their axes are nearly on a vertical line drawn from the axes of the bearings 24.

A pair of guide rollers 36 are mounted in fixed relationship to the lift truck 10, and a pair of movable guide rollers 38 are mounted on the rear end of the movable arm assembly 34.

A hydraulic cylinder 40, on each side of the truck, is utilized to extend and retract the arm assembly 34. When the arm assembly is retracted, the wheels 38 are moved towards the wheels 18 until the wheels 32 reach 'the position previously described. Obviously, the

cylinder 40 can be actuated in any desired amount so that the wheels 32 may be positioned in accordance with the operators desire.

, that the operation of the cylinders 40 can be utilized either to retract the load toward the vehicle, or to pull the entire truck body forward towards the load.

Referring now to FIGS. 4-7, the operation of the vehicle can best be described as follows: 1

The truck 10 with a load 55 on its forks, and the load wheels 32 extended to the optimum wheelbase, is brought to a stop at a given point with the load wheels 32 slightly beyond the opening into which the load is to be positioned. At this position the load is centered on the lift truck forks 30. I

As shown in FIG. 5 the operator then turns the truck and the load so that the outboard corner of the load just clears the far side. He then continues the pivot until the truck is in line with the area into which the load is to be stored. 'The vehicle has now reached the position shown in FlG 6.

The operator then sets the steering for straight ahead traveLand sets the brakes 33 located in the nonsteerable load wheels 32. With these brakes set, the hydraulic cylinders 40 that control the load arms are actuated, moving the entire truck body, mast, carriage, and load truck which may be utilized in spaces far narrower than those presently required by available lift trucks. It is realized, of course, that although the above description and the drawings have been directed towards a single embodiment of the invention, those skilled in the art will; readily see a variety of modifications thereto, without exceeding the purview of the following claims.

We claim: l. The process of placing a load in an assigned space utilizing a lift truck comprising a self-propelled chassis defining front and rear ends, a pair of arms retractably mounted on the front end of the chassis, a pair of forforward and into the load storage area. The side shifter carriage 28 may then be actuated by the operator to center the load within the storage area, so that the vehicle and load attain the positions shown in FIG. 7.-

in order to leave the load in the storage area, the forks are lowered to deposit the load and the hydraulic cylinders on the load arms are extended, causing the truck body, mast, carriage, and forks to move rearwardly. The operator may then turn the steerable wheels, release the brakeson the wheels 32, move the truck back to its original position and proceed to another location. Alternatively, the operator may simply drive the truck but of the space in a manner similar to well known fork lift trucks without extensible arms.

The removal of a load from the storage area requires the above sequence of events to be reversed.

Thus the applicants have provided a narrow-aisle ward nonsteerable wheels mounted on saidarms, mast means mounted on the front end of said chassis, carriage means vertically movably supporting load forks on said carriage means, a pair of rear steerable wheels mounted on the rear of said chassis, the forward and rear wheels having forward and rear independently operable brakes, respectively, and wheelbase changing means for extending and retracting said arms whereby the truck wheelbase may be changed, the process comprising the steps of positioning the truck with its wheelbase extended and a load on its lift forks adjacent to the outer edge of the assigned space with the forward wheels slightly beyond one side edge but between the side edges of the space, pivoting the truck until it is perpendicular to its original direction and is in line with the assigned space,holding the-forward wheels in position by applying the forward brakes, and shortening the wheelbase by actuating the wheelbase changing means so as to move the load into the assigned space.

2. The process of claim 1 including the steps of lowering the load into the assigned space, extending the wheelbase, and pivoting the rear of the truck until the truck reaches its original position.

3. The process of claim 2 including the steps of lowering the load into the assigned space, driving of the truck out of the space, and pivoting the rear of the truck until its longitudinal axis is parallel to the aisle.

4. The process of claim 1 further including sideshifter carriage means for shifting the carriage sideways and further including the step of actuating the sideshifter carriage means so as to laterally position the EJNETED ST TBS ?AT7ENT @EFKIE TEFZTCATE @F QQRRECTFUN Patent No. 3 703369 Dated Nov. 28, 1972 Inventor(s) Walter M. Shaffer and John '1. Crawford It is certified that error' appears in .the above-identified patent and that said LetterSPatent are hereby corrected as shown below:

In Claim 3, line 2, "of" should be deleted a f cer driving".

Signed and Sealed this 10th day of July 1973.-

(SEAL) Attest:

EDWARD M.FLETCHER,JR.

Rene Tegtmeyer Attesting Officer Acting Commissioner of Patents "ORM PO-105O (10-69) USCOMM-DC 60376-P69 uvs. covERriMENT PRINTING OFFICE: 1969 0-366-334

Claims (4)

1. The process of placing a load in an assigned space utilizing a lift truck comprising a self-propelled chassis defining front and rear ends, a pair of arms retractably mounted on the front end of the chassis, a pair of forward nonsteerable wheels mounted on said arms, mast means mounted on the front end of said chassis, carriage means vertically movably supporting load forks on said carriage means, a pair of rear steerable wheels mounted on the rear of said chassis, the forward and rear wheels having forward and rear independently operable brakes, respectively, and wheelbase changing means for extending and retracting said arms whereby the truck wheelbase may be changed, the process comprising the steps of positioning the truck with its wheelbase extended and a load on its lift forks adjacent to the outer edge of the assigned space with the forward wheels slightly beyond one side edge but between the side edges of the space, pivoting the truck until it is perpendicular to its original direction and is in line with the assigned space, holding the forward wheels in position by applying the forward brakes, and shortening the wheelbase by actuating the wheelbase changing means so as to move the load into the assigned space.

2. The process of claim 1 including the steps of lowering the load into the assigned space, extending the wheelbase, and pivoting the rear of the truck until the truck reaches its original position.

3. The process of claim 2 including the steps of lowering the load into the assigned space, driving of the truck out of the space, and pivoting the rear of the truck until its longitudinal axis is parallel to the aisle.

4. The process of claim 1 further including sideshifter carriage means for shifting the carriage sideways and further including the step of actuating the sideshifter carriage means so as to laterally position the load within the assigned space.

Images