US3241697A

US3241697A - Side shifting load handling apparatus for an industrial truck

Info

Publication number: US3241697A
Application number: US84715A
Authority: US
Inventors: Humbert R Rogant
Original assignee: Individual
Current assignee: Individual
Priority date: 1961-01-24
Filing date: 1961-01-24
Publication date: 1966-03-22
Anticipated expiration: 1983-03-22

Description

March 22, 1966 H. R. ROGANT SIDE SHIFTING LOAD HANDLING APPARATUS FOR AN INDUSTRIAL TRUCK 4 Sheets-Sheet 1 Filed Jan. 24, 1961 iiiifiiw INVENTOR Humbert R.Ro3a nt mg? W ORNEYS March 22-, 1966 H. R. ROGANT SIDE SHIFTING LOAD HANDLING APPARATUS FOR AN INDUSTRIAL TRUCK 4 Sheets-Sheet 2 Filed Jan. 24, 1961 mm m X INVENTOR Humbert R .Rogant 6 9 m m NW. My J n I IIIIIIII m u m9 l .||..nn I5 \9 4 Sheets-Sheet 4 mm QQ\ (v Q w INVENTOR Humbert R.Ro9ant BY 444 TTORNEYS 0 v 9 m X March 22, 1966 H. R. ROGANT SIDE SHIFTING LOAD HANDLING APPARATUS FOR AN INDUSTRIAL TRUCK Filed Jan. 24 1961 United States Patent 3,241,697 SIDE SHIFTING LOAD HANDLING APPARATUS FOR AN lNDUfiTRIAL TRUCK Humbert R. Rogant, RD. 1, Eddy Road, Willoughby Hills, Ohio Filed Jan. 24, 1961, Ser. No. 84,715 8 Claims. (Cl. 214-730) This invention relates generally to industrial lift trucks of the type widely employed for work handling purposes in factories, warehouses, storage yards and the like, and more specifically to improvements in the load handling mechanisms for such trucks.

The invention is particularly concerned with improvements in what are generally known as fork lift trucks and ram lift trucks. Lift trucks of these types are commonly characterized by a fork or ram, as the case may be, which projects from the forward end of the truck body and which is mounted for vertical reciprocation with respect thereto. In use the truck is manipulated to supportingly engage the fork or ram with a load so that it may be carried and deposited at a desired location.

In accordance with normal practice, lift trucks of the general character described are used to stack loads for storage purposes and to correspondingly remove the stacked loads from storage. The problems commonly encountered when employing conventional lift trucks for this and similar purposes have, however, made their use difiicult and have seriously hampered their effective operation. For example, efficient utilization of floor or yard space dictates that stored loads be stacked as high and as close together as possible, thus making it essential that the superimposed loads in one stack be vertically aligned with each other so that another stack may be formed in close adjacency therewith. Moreover, since various materials may be stacked as high as 20 feet or more, proper alignment of the superimposed loads is essential from a safety standpoint to assure a stably balanced stack. Because of the foregoing considerations, it is generally necessary that the stacking be carried out by moving each load along a straight run perpendicular to the forward face of the stack or pile, this being particularly true when a stack is to be formed between two existing ones. Conversely, the close adjacency of the stacks requires that the individual loads be removed by reverse movement along the same straight line path of stacking.

The problems involved in properly placing or removing individual loads arise from the obvious desirability of maintaining minimum aisle space between rows of stacks in order to conserve storage area. As a result, there is relatively little clearance at the sides of a truck in which it may be maneuvered to properly stack and unstack the loads. For example, when using a lift truck of conventional construction in which the fork or ram is laterally immovable, the operator is required to jockey the truck forward and backward until it is axially crosswise of the aisle, thereby positioning the ram or fork for side aisle loading or unloading. The confined space in which this maneuvering is accomplished necessitates considerable skill on the part of the operator and requires an excessive amount of time which results in the truck being tied up for prolonged periods in stacking or unstacking a single load.

Another disadvantage of the above described conventional lift truck construction is that the load at the front of the truck often obscures the operators view when the load is elevated. Consequently, it is difiicult for the operator to gauge the position of the load supported by the truck relative to the location in which the load is to be deposited.

In attempting to overcome the foregoing problems as- 3,241,697 Patented Mar. 22, 1966 sociated with side aisle loading, various prior art load carrying mechanisms have been evolved in which the forks or rams can be swung about a vertical pivot between their normal position in which they project axially forwardly of the truck bodies to a position in which they project laterally from the truck sides. In one known form of such construction the pivot for the loading engaging means was fixedly located at sides or center of the trucks at their front ends so that theoretically the supported loads could be directly swung into and out of stacked position instead of requiring the truck to be moved as a whole. Practical application of mechanisms of this type have proved largely unsuccessful, however, since the supported loads are frequently of a length which prohibits swinging movement of the loads in confined aisle spaces. Moreover, these prior art constructions could not be used effectively, if at all, to place or remove loads between adjacent existing stacks.

In another known type of construction, means were provided for sequentially moving the load engaging forks laterally of the lift truck after the fork had been swung about a vertical pivot. Although this feature of dual movement of the forks or rams presented some improvement over previous mechanisms in accomplishing side aisle loading, the limited lateral movement afforded to the forks usually did not permit a load to be either placed in accurately aligned position on a stack or to be withdrawn therefrom without considerable back and forth maneuvering of the lift truck. Moreover, in the usual construction the pivot for the forks remained fixed relative to the trucks until they had been turned to their laterally projecting position. As a result, supported loads still could not be expeditiously rotated in the limited available aisle space.

Most of the prior art movable load carrying mechanisms also are mechanically unstable because of the manner in which the forks and rams are connected to the lift trucks and thus are not capable of supporting loads of appreciable weight. In addition, the complexity of design neces sitates expensive and extensive modifications of the basic lift truck construction to accommodate such conventional mechanisms.

An object of the present invention is to provide an improved load handling mechanism for lift trucks of the type described.

A more specific object of the invention is to provide an improved load handling mechanism for a lift truck which facilitates side aisle loading and unloading.

Another object of the invention is to provide a rugged load carrying mechanism as generally described above, which is capable of supporting heavy loads and yet is of a relatively simple and inexpensive construction.

Still another object of the invention is to provide a load carrying mechanism of the character described which is readily adaptable to conventional lift truck constructions without necessitating extensive modifications thereof.

In accordance with the present invention, the foregoing objects are attained and the disadvantages of the prior art overcome by a novel mechanism which permits a load engaging fork or ram to be swung in a horizontal plane about a vertical pivot from a forwardly projecting position at the front of the lift truck to selected positions in which the fork or ram. projects from the truck sides. In order that relatively long and bulky loads can be swung in smaller confined aisle areas than theretofore possible, provision is made for simultaneously translating the pivot toward the truck side opposite to that toward Which the projecting load engaging means is swung. This construction advantageously permits the supported load to be swung in a horizontal arc-uate path even though the length of the load approximately equals the width of the aisle.

Provision is also made for moving the fork or ram transverse to the axis of the truck after it has been turned to its laterally projecting position so that the supported load can be elevated and properly deposited or removed from a stack without the necessity of moving the entire truck. Since the load is manipulated at the side of the truck instead of in front of it, the operator has an unobstructed view of the load and stack and thus is able to adjust the position of the load with greater accuracy and ease than is possible with most prior art load handling mechanisms. As a result, less time and skill is required on the part of the operator to effect final placement of the load.

Another advantage afforded by the invention is that it may be used in conjunction with the conventional type of lift truck having a vertical mast which carries an elevator carriage. The construction of the load handling mechanism comprising the invention permits it to be easily attached to the elevator carriage of such a lift truck in a manner which results in an ability to support the heavy loads which are commonly encountered in lift truck applications.

Other objects and advantages of the invention will become apparent from the following detailed description and the accompanying drawings.

In the drawings:

FIGURE 1 is a plan view of a conventional lift truck employing a load handling mechanism constructed according to the invention;

FIGURE 2 is a side elevational view of the apparatus shown in FIG. 1;

FIGURE 3 is a front elevational view taken along the line 33 of FIG. 2;

FIGURE 4 is a vertical cross-sectional view taken along the line 44 of FIG. 3;

FIGURE 5 is a fragmentary plan view taken along the line 5-5 of FIG. 3;

FIGURE 6 is a view showing a preferred actuating system for controllably operating the load handling mechanism.

Referring now to the drawings, and to FIGS. 1 and 2 in particular, there is shown a conventional fork lift truck 10 to which the mechanism of the invention may be expeditiously connected and used in conjunction therewith. It is to be understood, however, that the particular construction of the truck itself is in no way limiting of the invention and has been illustrated only for the purposes of showing the general type of apparatus to which the invention may be advantageously applied.

As shown the truck 10 is comprised generally of a body portion 11 which includes front and

rear wheels

12 and 13, respectively, and an operator cockpit 14 in which are disposed the various controls 15 and steering apparatus 16. The motor and associated drive mechanism for thetruck are located in the rear portion 17.

Connected to the front of the truck body 11 is the usual vertical mast 23 which cooperates with the rollers 24 (FIG. 5) of the elevator 25 to guide the elevator for vertical reciprocation. The elevator is raised and lowered in the customary manner by a hoist chain 26 which is operatively connected to the elevator and to a suitable fluid actuator 27 shown in dot-dash outline in FIG. 5.

In accordance with the invention, there is connected to the front face of the elevator 25 a main carriage 30 which has a limited amount of movement transverse to the longitudinal axis of the truck 10. The main carriage 36 in turn carries a fork carriage 31 to which are connected the load engaging forks 32. The fork carriage 31 is adapted to be swung about a vertical pivot between a first position A in which the forks 32 extend forwardly of the truck and a second position B, shown in dot-dash outline in FIG. 1, in which the forks are at right angles to their first position. The fork carriage 31 also is movable from one side of the main carri ge 30 to the other side so that a load 4 supported by the forks may be projected beyond a side of a truck 10 to dot-dash position C.

In its general mode of operation, the truck 10 may make a straight run toward a pallet or other load to engage the forks 32 therewith while in position A. The load is then elevated by operation of the elevator 25 and carried to a location where it is to be deposited. In situations of side aisle stacking, the fork carriage 31 may be pivotally and laterally moved to position B and the elevator 25 raised or lowered to locate the load at the desired height. Subsequent lateral movement of the fork carriage and, if necessary, of the main carriage 30 to position the forks 32 at position C, serves to effect final accurate placement of the load. Removal of a load from a stack may be accomplished by reversing the foregoing operations, that is, moving the forks 32 from position C to position A.

Referring now to the detailed construction shown in FIGS. 3, 4 and 5, the main carriage 30 is comprised primarily of a flat rectangular plate 35 substantially corresponding to the elevator 25. In the preferred form of construction, the plate 35 is movably connected to the elevator by means of a pair of upper and lower

horizontal rollers

36 and 37, respectively, and a pair of vertical rollers 38. The rollers 36 are mounted at either end of the plate 35 by brackets 39 which extend across the top of the elevator 25 so that the rollers may rollingly engage the rear surface thereof. The vertical rollers 38 are journalled within the brackets 39 on roller pins 40 and engage the top surface of the elevator. The lower horizontal rollers 37 engage the front surface of the elevator and are rotatably connected at either end of the plate 35 on the lower edge thereof. Instead of providing the illustrated rollers, the plate 35 may be simply hung on the elevator 25 by slidably engageable arms.

A limited amount of transverse movement of the main carriage 30 is imparted by a two-way fluid actuator 41, the cylinder of which is fastened to a central portion of the elevator 25 and the piston to the plate 35. The actuator 41 acts to the left, as viewed in FIG. 3, and its position is such that when its piston is retracted, the main carriage will be centered on the elevator 25. Concomitantly, when the piston is extended, the main carriage will be moved toward the left end of the elevator. As will hereinafter be made more apparent, a main carriage movement of approximately one-half foot is normally sufficient to effect the improved operation of the invention. Corresponding

openings

42 and 43 in the elevator 25 and plate 35, respectively, facilitate mounting of the actuator 41 and permit movement of the main carriage.

It will be apparent that movement of the main carriage 30 may be effected by other means than the disclosed fluid actuator 41. For example such movement could be accomplished by a motor driven lead screw, or by a cooperating rack and pinion. Other suitable expedients will be obvious to those skilled in the art.

The main carriage structure is completed by a pair of vertically separated, horizontal guide beams 44 and 45 which are welded to the plate 35 in spaced relation to its front surface, and by a lower guide beam 46 which extends between the ends of the plate 35 at its lower edge.

In the illustrated embodiment, the fork carriage 31 is formed by a carriage base 60 which has a height substantially equal to the main carriage 30 and a relatively short horizontal length. As shown most clearly in FIGS. 3 and 4, this carriage base is rollingly supported on the guide beams of the main carriage by upper and lower sets of

horizontal rollers

51 and 52, respectively, and by intermediate sets of

vertical rollers

53 and 54. The upper horizontal rollers 51 are carried at the ends of the carriage base 60 by a generally L-shaped bracket 55 fixed to the top of the carriage base, the bracket extending across the top of the guide beam 44 so that the rollers may engage its rear surface. The lower horizontal rollers 52 also are disposed at either end of the carriage base and are carried by a bracket 56 so that they may engage the front edge surface of the guide beam 46.

Intermediate rollers

53 and 54 are journalled directly to the carriage base 60 and are positioned to engage the top and bottom edge surfaces, respectively, of the guide beam 45. The carriage base 60 also includes a vertical support 50 connected between the

brackets

55 and 56.

A pair of vertically spaced plates 67 are swingably mounted on the fork carriage base 60 by means of a vertical shaft 61 which is rigidly connected to corresponding ends of the plates and rotatably journalled in a sleeve 62. The sleeve 62 is connected between the

brackets

55 and 56 adjacent the support 50. As shown in FIGS. 3 and 5, the plates 67 are connected at their ends opposite to the shaft 61 by a strap 70. In order that the fork carriage plates 67 may be turned from a first position in which they are parallel to the main carriage plate 35 to a second position in which they are at right angles thereto, there is mounted on the top of the bracket 55 a reversible fluid motor 63. A pinion 65 secured to the mot-or shaft 64 (FIG. 4) cooperates with a sector gear 66 which is fastened to the top of the shaft 61.

The load engaging forks 32 are adjustably supported on the fork carriage plates 67 so that they may be moved toward or away from each other depending upon the width of the load. To facilitate this adjustable mounting, each fork 32 has vertically spaced hooks 68 and 69 which extend rearw-ardly from the upright leg of the fork. The upper hooks 68 are engaged over the top edge of the upper plate 67 while the lower hooks 69 similarly engage the top edge surface of the lower plates 67.

In the illustrated embodiment of the invention, horizontal reciprocal movement is imparted to the fork carriage 31 by a pair of oppositely acting, two-

way fluid actuators

75 and 76, both of which are rigidly secured to the front surface of the main carriage plate 35. The connections between the fluid .

actuators

75 and 76 and the fork carniage 31 are such that the carriage may be moved in either direction twice the distance of the piston stroke of the motivating actuator. To this end, one end of a chain 77 is connected at 78 to the forward end. of the actuator 75, which acts to the right as viewed in FIG. 3. This chain 77 is entrained around a cooperating gear 79 carried by the piston rod of the actuator 75 and has its other end fastened at 80 to the fork carriage base 60. The actuator 76, which acts to the left as viewed in FIG. 3, is similarly connected to the fork carriage by a chain 81 which has one end fastened at 82 to the forward end of the actuator. The chain 81 is entrained around a cooperating gear 83 carried by the piston rod of the actuator 76 and has its other end fastened to the fork carriage base 60 at 84. As shown most clearly in FIGS. 4 and 5, the relative positions of the

actuators

75 and 76 are such that, when the fork carriage base 60 is moved to the left end of the main carriage 30 by the actuator 76, the forks 32 will be centered with respect to the main carriage and the longitudinal axis of the truck 10.

As in the case of the above-described actuator for the main carriage 30, it will be apparent other mechanisms than the disclosed

actuators

75 and 76 and the associated chain drive could be provided for moving the fork carriage 31. For example, it is contemplated that the fork carriage could be moved by a single double-acting fluid actuator.

Reference is now made to FIG. 6 which illustrates a preferred fluid actuating and control system for the abovedescribed apparatus. As shown fluid is supplied to the various fluid actuators and to the fluid motor 63 from a suitable reservoir 90. The reservoir may be located in the truck body 11 and connected to the actuators and fluid motor by flexible conduits which will now be described in detail.

Reference numeral 91 designates a supply conduit in which is disposed a pump 92. This conduit is connected between the reservoir 90 and a 4-port, two-way carriage control valve 93 which forms part of the controls 15 in the truck cockpit 14. In one position of the valve 93, the supply conduit 91 is in fluid communication with the conduit 94 through which fluid is admitted into the rear end of the actuator 76, thereby effecting movement of the fork carriage 31 to the left as indicated in FIG. 6.

The conduit 94 also communicates with a conduit 96 which in turn connects to the rear end of the main carriage actuator 41. Sequential movement of the main carriage 30 is effected by disposing in the line 96 a conventional pressure operated sequence valve 97 which blocks fluid flow in the direction indicated by the arrow until a predetermined pressure value is built up in the line 94. Thereupon the valve 97 opens permitting fluid to enter the actuator 41 and moves the main carriage 30 to the left as viewed in FIGS. 3 and 6. The valve 97 operates in the usual manner by permitting free flow in a direction opposite to that indicated by the arrow.

When the carriage control valve 93 is moved to its second position, the fluid supply conduit 91 is connected to a conduit 100 which communicates with the forward end of the main carriage actuator 41 and the rear end of the fork carriage actuator 75. A sequence valve 101, similar to the valve 97, is disposed between the actuators 41 and '75 to act in the direction of the arrow. This valve 101 also provides for a sequential operation in which the main carriage is first moved by the actuator 41 to the right to center it on the elevator 25. When the pressure in the conduit 100 subsequently reaches a predetermined value, the valve 101 opens to admit fluid to the actuator 75, thereby effecting movement of the fork carriage 31 to the right end of the main carriage 30.

When the carriage control valve 93 is positioned to connect conduits 91 and 94 to thereby power the actuator 76, the conduit 100 is simultaneously connected to a return line 102 which leads back to the reservoir 90. This connection between the

conduits

100 and 102 affords an exhaust path for fluid expressed from the

actuators

41 and 75. A branch line 103 between the forward ends of the

actuators

75 and 76 completes a closed fluid circuit in which fluid forced from the cylinder 76 by its advancing piston is free to flow into the cylinder of the actuator 75 behind its oppositely acting piston.

The carriage control valve 93 connects

conduits

94 and 102 when conduit 100 is connected to source. In this position of the valve, fluid expressed from the

actuators

41 and 76 flows through

conduits

94, 96 and 102 to the reservoir 90. At the same time, the line 103 permits fluid forced from the forward end of the actuator 75 to flow into the forward end of the oppositely acting actuator 76.

A branch supply line 104 affords fluid communication between the main supply line 91 and a 4-port, two-way motor control valve 105 which is similar to the valve 93. This valve 105 also forms a part of the truck controls 15.

In one position of the motor control valve 105, the supply conduit 104 is connected to a conduit 106 which leads to the fork carriage turning motor 63, thereby effecting turning movement of the fork carriage 31 in one direction. When the valve is in this position, the conduit 107, which also leads to the motor 63, is placed in fluid communication with a branch return line 108 which is in turn connected into the main return line 102.

Turning movement of the fork carriage 31 in the opposite direction is effected by moving the control valve 105 to its second position in which the

conduits

104 and 107 are placed in fluid communication and the conduit 106 is connected to the exhaust line 108.

The combined operation of the load handling mechanism and fluid control system comprising the present invention will be clearly apparent when FIGS. 5 and 6 are considered in conjunction. In the illustrated position of the load handling mechanism, the fork carriage 31 is centered on the main carriage 30 with the carriage actuator 76 fully extended and the oppositely acting actuator 75 fully retracted, and the fork carriage plates 67 are transverse to the longitudinal axis of the truck 10 so that the load engaging forks 32 extend forwardly of the truck. The main carriage 30 is in turn centered with respect to the elevator 25 with the actuator 41 fully retracted.

When the carriage control valve 93 is positioned to connect conduit 100 to source and conduit 94 to exhaust, pressure will build up in the conduit 100 until the sequence valve 101 opens to admit fluid into the actuator 75. Thereupon, the actuator 75 will extend to power the fork carriage 31 to the right until the carriage base 60 reaches the right end of the main carriage 30. During the travel of the fork carriage, the forks 32 may be turned to extend transversely of the longitudinal axis of the truck by positioning the motor control valve 105 to connect conduit 106 to source and conduit 107 to exhaust. The fork carriage 31 may be turned, however, either before or after the actuator 75 is energized.

After the fork carriage has been thus moved across the face of the main carriage and after the forks have been rotated, the carriage control valve 93 may be set in its second position to connect conduit 94 to source and conduit 100 to exhaust. Thereupon the actuator 76 is extended to move the fork carriage base 60 back to the left end of the main carriage 30. Since the fork carriage plates 67 are now parallel to the truck axis, this movement of the fork carriage will be effective to extend the load engaging forks 32 beyond the left side of the lift truck. If desired, the forks 32 may be further extended beyond the side of the truck by maintaining the control valve 93 in its second position until the sequence valve 97 opens and fluid is admitted to the actuator 41. Alternatively, the lateral movement of the fork carriage 31 may be stopped at any desired time by simply releasing the control for the carriage control valve 93.

The foregoing sequence of operations is reversed by reconnecting the conduit 100 to source and the conduit 94 to exhaust. Thus connected, fluid first enters the forward end of the main carriage actuator 41 to center the main carriage 30 on the elevator 25. Thereupon fluid pressure increases in the conduit 100 until the sequence valve 101 opens and the actuator 75 is caused to move the fork carriage base 50 back to the right side of the main carriage. During this movement, the motor control valve 105 may be positioned to connect the conduit 107 to source and conduit 106 to exhaust so that the motor 63 is actuated to turn the fork carriage plates 67 to their original position shown in FIG. 5. Subsequent actuation of the actuator 76 returns the fork carriage base 60 to the left side of the main carriage, thereby completing a cycle of operations.

Consideration will now be given to a typical loading operation in which loaded pallets or the like are to be transported to a storage area and piled in closely adjacent stacks at either side of a narrow aisle. In carrying out this operation, the truck operator may engage the load on the forks 32 in the usual way by making a straight run at the load with the forks projecting from in front of the truck. The elevator 25 is then raised, as shown, for example, in FIG. 2, and the truck driven to the storage area. When utilizing the particular construction of the invention illustrated in the drawings, the truck 10 enters the aisle so that the left side of the truck, as viewed in FIG. 3, corresponds to the side of the aisle on which the load is to be deposited.

Assuming that the truck 10 has reached the desired location along the aisle and the load has been elevated to the required height, the operator has merely to energize the fork carriage actuator 75 and the turning motor 63 to swing the forks 32 so that they are cross-wise of the aisle and in position to advance the load into the storage space.

Inasmuch as the pivot for the carriage plates 67 may be translated to right as the forks are swung in the opposite direct-ion, the load carried by the forks can be rotated without striking stacks on either side of the aisle even though the length of the load is approximately the width of the aisle. Instead of vertically positioning the elevator 25 and then laterally translating and rotating the fork carriage 31 in two separate operations, it will be obvious that a skilled operator may effect the separate movement simultaneously by means of the controls 15. Moreover, these combined movements may be accomplished at the same time the truck is being driven to the loading position.

In the final part of the loading operation, the fork carriage actuator 75 is energized to move the load toward the side of the aisle on which it is to be placed. The straight line movement of the forks 32 permits the engaged load to be inserted between existing stacks without danger of hitting any previously positioned loads. The operator has then only to lower the load onto the stacks and withdraw the forks by again energizing the actuator 75.

It will be noted that, with a lift truck equipped with a load handling mechanism constructed according to the invention, the load may be accurately deposited on a stack without necessity of turning and extensively maneuvering the truck as is required with many prior art apparatus. For example, proper alignment of the side edges of the load is attained by simply centering the load on the stack when stopping the truck. Exact positioning of the front edge of the load in parallel vertical alignment with the front face of the stack is facilitated by the combined lateral movements of the main carriage 30 and the fork carriage 31. In most applications, the operator normally will move the load engaging forks 32 as far forward as possible under a load when picking it up with the upright portions of the forks engaging the load, and will necessarily stop the truck at the loading position with its side spaced from the front face of the stack. As a result, it will be obvious that the front edge of the load cannot be vertically aligned with the front of the stack solely by movement of the fork carriage 31. It is for this reason that the main carriage 30 is made shiftable on the elevator 25. As noted above, lateral movement of the main carriage a distance of approximately one-half foot is usually ample to overcome the clearance between the side of the truck and the stack, however, this amplitude of motion may obviously be increased if necessary. The unobstructed view afforded to the operator by the side positioning of the load also facilitates its being deposited in the proper location.

Obviously, many variations and modifications of the invention will be apparent to those skilled in the art in light of the above teachings. It is to be understood, therefore, that the invention may be practiced within the scope of the appended claims otherwise than as specifically shown and described.

What is claimed is:

1. In an industrial lift truck of the type including a truck body and a vertically movable elevator at one end of said truck body, the improvement comprising main carriage means mounted on said elevator for horizontal reciprocation, fork carriage means mounted on said main carriage means for horizontal reciprocation with respect thereto, load engaging means connected to said fork carriage means, and means for actuatably moving said main carriage means and said fork carriage means independently.

2. The apparatus claimed in claim 1 wherein said actuation means sequentially moves said main carriage means and said fork carriage means.

3. The apparatus claimed in claim 1 including vertical pivot means connecting said load engaging means to said fork carriage means and means for turning said load engaging means about said vertical pivot means to position it transverse to the longitudinal axis of said truck body.

4. In an industrial lift truck of the type including a truck body and a vertically movable elevator carried at one end of said truck body, an improved load handling mechanism comprising a main carriage, said main carriage including a main carriage plate having a length substantially equal to the width of said truck body, means mounting said main carriage plate on said elevator for reciprocation between a normal position in which said plate is centered with respect to said end of truck body and a position in which one end of said plate extends beyond one side of said truck body, actuating means carried by said elevator for reciprocating said main carriage, load engaging means having a free end portion adapted to supportingly engage a load, means connecting said load engaging means to said main carriage for reciprocating said load engaging means, main carriage plate, and actuating means connected to said main carriage for reciprocting said load engaging means, said connecting means for said load engaging means comprises a fork carriage, said fork carriage including a fork carriage base reciprocally mounted on said main carriage plate, and a fork carriage plate connected to said base, said load engaging means being fastened to said fork carriage plate, said fork carriage plate is connected to said base by vertical pivot means for permitting said fork carriage plate to be swung between a position transverse to the longitudinal axis of said truck body and a position parallel to said longitudinal truck axis, and including actuating means connected to said base for swinging said fork carriage plate, the actuating means for reciprocating said fork carriage on said main carriage plate and for swinging said fork carriage plate are operable simultaneously, the actuating means for reciprocating said main carriage on said elevator and for reciprocating said fork carriage on said main carriage are operable sequentially.

5. The apparatus claimed in claim 4 wherein said load engaging means comprises a fork.

6. An industrial lift truck comprising a truck body, an upright mast connected to one end of said truck body, a vertically movable elevator carried by said mast, said elevator having a length substantially coextensive with the width of said truck body, a main carriage plate substantially coextensive in length With said elevator, said main carriage plate being disposed in a vertical plane with its length transverse to the longitudinal axis of said truck body, means connecting said main carriage plate to said elevator for movement between a position in which said main plate is centered with respect to said elevator and a position in one end extends beyond one side of said truck body, roller guide means horizontally extending across the face of said main carriage plate, a fork carriage base, said base having rollers engaged with said guide means and being shiftable from one end of said main carriage plate to the other, a vertically disposed fork carriage plate, said fork carriage plate being pivotally connected to said base for pivotal movement between a first position parallel to said main carriage plate and a second position at right angles thereto, load engaging means carried by said fork carriage plate, and actuating means for moving said main carriage plate, said fork carriage base and said fork carriage plate, said actuating means comprises a reversible fluid actuator connected between said elevator and said main carriage plate, a pair of oppositely acting fluid actuators connected between said main carriage plate and said fork carriage base, and a reversible fluid motor mounted on said fork carriage base and operatively connected to said fork carriage plate.

7. The apparatus claimed in claim 6 wherein said fluid motor is operable simultaneously with at least one of said oppositely acting fluid actuators so that said fork carriage base may be moved to one end of said main carriage plate while rotating said fork carriage plate between said first position and said second position.

8. The apparatus claimed in claim 7 wherein each of said oppositely acting fluid actuators and said reversible fluid actuator are operable sequentially to produce sequential movement of said main carriage plate and said fork carriage base.

References Cited by the Examiner UNITED STATES PATENTS 1,614,769 1/1927 Amsler 212-73 X 1,828,307 10/1931 Been.

2,424,899 7/ 1947 Priester 212-15 2,663,443 12/ 1953 Schenkelberger 214-731 2,732,083 1/1956 Smith 214-658 2,799,418 7/ 1957 Haldimann 214-730 2,851,182 9/1958 Gehring 214-730 2,886,197 5/1959 Harris 214-653 2,945,610 7/1960 Wendt 214-730 FOREIGN PATENTS 1,038,163 5/1953 France.

750,793 6/ 1956 Great Britain.

GERALD M. FORLENZA, Primary Examiner.

MORRIS TEMIN, HUGO O. SCHULZ, ERNEST A. FALLER, Examiners.

Claims

1. IN AN INDUSTRIAL LIFT TRUCK OF THE TYPE INCLUDING A TRUCK BODY AND A VERTICALLY MOVABLE ELEVATOR AT ONE END OF SAID TRUCK BODY, THE IMPROVEMENT COMPRISING MAIN CARRIAGE MEANS MOUNTED ON SAID ELEVATOR FOR HORIZONTAL RECIPROCATION, FORK CARRIAGE MEANS MOUNTED ON SAID MAIN CARRIAGE MEANS FOR HORIZONTAL RECIPROCATION WITH RESPECT