US3281119A - Fork lift with forward reach - Google Patents

Description

Oct. 25, 1966 P. J. WESTFALL FORK LIFT WITH FORWARD REACH Filed April 10, 1964 .3 Sheets-Sheet 1 Paul J Wesffal/ INVENTOR. wan

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Oct. 25, 1966 P. J. WESTFALL FORK LIFT WITH FORWARD REACH 5 Sheets-$heet 2 Filed April 10, 1964 Fig. 4

Paul J. Wesffa/l IN VENTOR.

WW 3m Oct. 25, 1966 P. J. WESTFALL FORK LIFT WITH FORWARD REACH 5 Sheets-Sheet 5 Filed April 10, 1964 Paul J. Wesffal/ INVENTOR United States Patent 3,281,119 FORK LIFT WITH FORWARD REACH Paul J. Westfall, 4444 W. Burnside, Portland, Oreg. Filed Apr. 10, 1964, Ser. No. 358,818 Claims. (Cl. 254139.1)

The present invention generally relates to a lift device or loading device adapted to be mounted on a tractor or similar type of vehicle and which generally is in the form of a fork lift or bucket loader supporting frame having peculiar adaptations for rendering the device especially useful in the handling of logs although the device does have general utility.

An object of the present invention is to provide a fork lift or loader assembly having incorporated into its structure a means for introducing a forward reach to the fork lift or bucket loader thus enabling an operator to reach out for the load such as reaching the slope of a log deck.

Another feature of the present invention is to provide a fork lift or bucket loader having a forward reach which not only will enable the operator to reach out for the load but also enable the operator to pull the load back nearer the center of the carrying axle of the tractor or vehicle while travelling with the load.

Another feature of the present invention is to provide a fork lift or bucket loader having a forward reach which will enable a truck to be unloaded from either side without necessitating that the truck turn around.

Still another important feature of the present invention is to provide a fork lift or bucket loader incorporating structural features which enable the operator to have better visibility thereby eliminating danger to ground personnel as well as the drivers of trucks and the like.

Yet another object of the present invention is to provide a fork lift or bucket loader having structural features incorporated therein to provide a substantially constant lifting capacity throughout the lifting cycle and also to provide more ground clearance for manipulation of the tractor.

Generally, it is of primary importance that the present invention provides a combination load skidder and loading tractor whereby the logs may be more expeditiously handled in a safer and more eflicient manner with the over-all structure being relatively simple but yet rugged and long lasting and relatively inexpensive to maintain and operate.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

FIGURE 1 is a side elevational view of the fork lift of the present invention illustrating the structure of the present invention in retracted position;

FIGURE 2 is a side elevational view similar to FIG- URE l but with the structure being used to skid logs;

FIGURE 3 is a detailed sectional view taken substantially upon a plane passing along section line 33 of FIGURE 2 illustrating certain of the structural details of the invention;

FIGURE 4 is a rear elevational view of the construction of the present invention with portions thereof broken away;

FIGURE 5 is a top plan view of the construction of the present invention with portions thereof broken away;

FIGURE 6 is a longitudinal, sectional view taken substantially upon a plane passing along section line 66 of FIGURE 5 illustrating the structure of the present invention in which the fork lift or bucket loader has been extended for reaching out and obtaining a load; and

FIGURE 7 is a schematic perspective view illustrating the orientation of the mechanical and power operated components.

Generally, logging operations and timber harvesting lands employ a tractor as a primary working tool. As soon as the first access road is formed until the last log is harvested and loaded in the mill, the tractor plays a significant part in the logging operation. Thus, while the present invention is primarily intended for use in a logging operation, it may be also readily used in road building operations, various military uses, various harvesting uses and for general utility purposes but will be described with reference to logging operations. In modern-day logging operations, a logger may be required. to log 10 times the area that was previously logged in order to get a particular quantity of timber due to tree thinning operations and the like which requires that only a small portion of the standing timber be harvested.

A practical log handling tractor must have rugged strength together with a abundance of power and a flexibility adapting the tractor for many diverse uses. For example, a bulldozer blade, power winch and fork lift can be combined with well known endless track type or wheel tractors in which the tractor and blade are first used to form and grade the access roads and clear an assembly area. After a crew fells the trees, the tractor, winch and fork lift frame are used to bring the logs to the loading point and the tractor with fork lift is used to load the logs on the truck for shipment to the lumber mill. Upon reaching the lumber mill, this same type of tractor with the fork lift is used to unload the trucks, deck the logs and possibly feed the mill.

Many mechanisms of a hoist-type have been suggested for use with a fork lift. For example, a wide variety of gear, cam and lever actuation mechanisms have been com bined with many varieties of cable lifts and generally inadequate structures for use in the logging and construction industries. Accordingly, the improvement of the present invention resides in the fork lift and bucket loader art and provides a practical, efficient, log handling assembly while at the same time retaining the fundamental simplicity essential to the continued maintenance of efficiency in those regions far removed from repair and maintenance shops.

Primarily, the present invention provides an adjustable fluid power operated forward reach fork lift for use on a tractor for log handling in the woods and mill yards. Also, the present invention provides a tractor for use as a skidding tractor for skidding logs as well as a loading tractor for loading and unloading logs all in one unit having a fluid power adjustment for control of the lifting device. The particular orientation of the hoist cylinders enables the present invention to accomplish a much higher lift than with conventional fork trucks which are limited in their lifting height capacity. The present invention also incorporates two power pumps so that the load can be raised and extends forwardly or backwardly simultaneously thus enabling the operator to raise and reach at the same time and still obtain the full load on each cycle.

Referring now specifically to the drawings, the numeral 10 generally designates the fork lift structure or bucket loader of the present invention which is mounted on a suitable tractor type vehicle generally designated by the numeral 12 and including supporting wheels 14, an operators cab 16, a swivelled operators seat 18 by virtue of which the operator may either face forwardly over the forward end of the cab as illustrated in FIGURE 2 or he may face rearwardly over the fork lift or loader bucket structure as illustrated in FIGURE 6 with the operator being designated by the numeral 20. A suitable steering wheel 22 is provided along with other conventional controls for operating the tractortype vehicle 12 in a conventional manner. When the operator faces the fork lift or bucket loader it is provided with a control panel 24 for manipulating the fork lift 10 in a conventional manner. While the device has been illustrated attached to a wheeled-type tractor, it is pointed out that it could just as Well be associated with an endless track type of vehicle with it only being essential that the supporting framework 26 be provided on the tractor-type vehicle for supporting the fork lift or bucket loader 10.

The fork lift or bucket loader structure includes a pair of arms 28 which have one end pivotally attached to brackets 30 secured to the frame or deck 26 of the vehicle and which extends generally upwardly therefrom for swinging movement in a vertical plane about a transverse pivot pin 32. The arcuate and vertical position of the arms 28 are controlled by a hydraulic motor 34 of the piston and cylinder type having a piston rod 36 pivotally attached to upwardly extending lugs 38 by a pivot pin 40 in which the lugs are orientated on the edge of the arms 28 nearest the tractor cab 16 as illustrated in FIG- URES l, 2, 6 and 7. The hydraulic motor 34 also in cludes a cylinder 42 pivotally attached to mounting lugs 44 by a pivot pin 46 with the lugs 44 being secured to the frame or deck 26 whereby extension and retraction of the hydraulic motor 34 will cause swinging movement of the arms 28 in a vertical plane about transverse pivot pins 32.

The arms 28 are of hollow box-like construction and provided with a pair of attaching ears 48 at the end thereof which receives the mounting lug 30. At the other ends of the arms 28, there is provided a pair of attaching cars 50 which pivotally receive therebetween an elongated main lift arm assembly 52 which is pivotally connected to the arms 28 by pivot pins. 54. The main lift arms 52 are provided with an offset or widened portion 56 generally in the center thereof and an elongated main hoist hydraulic motor 58 is received between the side walls 60 and 62 of the main lift arms 52 and the hydraulic motor 58 includes a main hoist cylinder 64 pivotally mounted at its inner end to the apex of the offset portion 56 of the main lift arm 52 by employing a pivot pin or trunnion 66. Hydraulic motor 68 also includes a piston rod 58 which extends between the walls of the arms 28 and is pivotally secured thereto by a pivot pin or trunnion 70 which is generally adjacent the point of connection between the piston rod 36 and the arms 28 but is located slightly below this pivot point and to the other side of the arms 28 when the arms 28 are in vertical position. Also, the arms 28 have a slightly offset portion 72 in the edge thereof facing the main lift arm and the pivot pin or trunnion 70 is oriented in the apex portion of this slightly offset portion.

Pivotally attached to the outer end of each of the main lift arms 52 is a load carrying assembly 74 of generally triangular configuration with the load carrying assembly 74 being pivotally attached to the outer end of the main lift arm 52 by pivot pins or trunnions 76. The load carrying member 74 is provided with an arcuated load engaging portion 78 and projecting forks or tines 80 thereon projecting from the lower edge thereof for engaging under the load such as a plurality of logs 82 as illustrated in FIGURE 6. The load engaging edge 78 is defined by an arcuated plate 84 as also illustrated in FIGURE 6 for securing the logs in place and engaging the logs when being gripped. A hydraulic motor 86 interconnects the main lift arm 52 and the load carrying assembly and includes a cylinder 88 pivotally attached to a bracket 90 carried by the upper edge of the lift arms 52 by a pivot pin or trunnion 92. The other end of the hydraulic motor 86 is provided with a piston rod 94 pivotally attached to the load carrying member by a pivot pin 96 or a suitable trunnion whereby the angular orientation of the load carrying element 76 may be varied in relation to the lift arm 52 about pivot pin 96.

Attached to the upper forward end of the load carrying element 74 is a pair of gripping forks or tines 28 pivotally attached thereto by a shaft 100 rigid in relation thereto. The shaft 180 is provided with an offset arm 102 rigid therewith connected to one end of a hydraulic motor generally designated by numeral 194 and which includes a piston rod 106 pivotally connected to the offset arm 102 on the trunnion or shaft 100 to which the gripping forks or tines 98 are also rigidly affixed. The motor 104 also includes a hydraulic cylinder 108 attached to a supporting lug 110 by a pin or trunnion 112 whereby expansion and contraction of the hydraulic motor 104 will cause swinging movement of the gripping forks or tines 88 from the open position illustrated in FIGURE 1 to the closed position illustrated in FIGURES 2 and 6.

For rigidifying and maintaining the gripping forks 98 in constant orientation, the gripping forks 98 are interconnected by a shaft or rod 114 and end plates 116 with suitable reinforcing gussets 118 at the ends thereof. Also, the various shafts and pivot points may extend between the arms and it will be understood that the arms symmetrical about the longitudinal axis as illustrated in FIG- URE 5. For example, the arm 28 are interconnected by a transverse plate 120 and the trunnion or pivot point 54 is in the form of a rod or shaft 122 which extends completely across the tractor structure. This is also true of the pivot point 76 which is in the form of a shaft 124 and this is also true of the trunnion or shaf 100 and it is pointed out that the gripping members 78 are also secured together by transversely extending plates 126 in which the arcuated plates 84 are only at the ends of the plates 136.

Also provided on one of the left arms 52 is a fair lead pulley 128 for receiving a cable 130 thereover which has the other end wound upon a powered winch 132 whereby the cable 130 may be wrapped around one end or otherwise secured to one end of a log 134 by using a suitable pair of gripping tongs or any other suitable means for connecting the cable to the log 134 whereby the tractor vehicle may be used as a skidding tractor in which event the lifting arms 52, the load carrying elements 74 and the arms 28 would be orientated in the position illustrated in FIGURE 2 and the operator 21) would face forwardly so that the logs could be skidded to a desired location.

Also, each of the fluid motors 34, 58, 86, and 104 are double-acting and have fluid pressure lines such as hydraulic lines 136 connected to opposite ends thereof in a conventional manner with the hydraulic lines 136 ex tending into the control panel 24 for control therefrom with there being provided two hydraulic pumps (not shown) for supplying pressure to the hydraulic system. Such pumps may be driven from the tractor engine or independently driven and the winch structure 132 may also be driven from a power take-off or indepedently driven.

Any control panel may be employed for controlling the operation of the various hydraulic motors. The control panel may be simplified by providing a push button assembly 138 for individually controlling each of the hydraulic motors for independently controlling each of the motors and also enabling several of the motors to be employed simultaneously. For example, the load gripping motor 194 would normally be operated to securely grip the load prior to operation of the tilt motor 86. However, as soon as the load has been gripped, the tilt motor may be operated to tilt the load upwardly if desired. Then, the main hoist motor 58 may be extended or retracted either independently of or simultaneously with the forward extension motor 34. Thus, the load may be lifted upwardly and at the same time projected away from the tractor or drawn towards the tractor.

For example, if the load is to be moved over the road, normally, the load would be moved toward the tractor for orientating the load closer to the tractor for easier control of the load. However, in some instances, it may be just as desirable to simultaneously -lift the load and also extend the fork lift structure to its forwardmost reach as illustrated in FIGURE 6. Also, the orientation in FIGURE 6 enables a truck load of logs to be loaded from the side of the truck opposite from which the tractor is disposed without the truck turning around. By mounting the main hoist motors on the lift arms with the piston rods down and connected to the arms 28, enables a higher lift to be attained when the piston is forced completely down to the inner ends of the main hoist cylinder 64. Present-day units mount the cylinder between the main boom and lift frame and are limited in their lifting height capacity since the lower limits is determined by the length of the cylinder which is no limit insofar as the lower limit is concerned in the present invention.

As illustrated, the pivot point for the hoist cylinder 64 where it connects to the main lif-t arm 52 begins at a point approximately forty-five degrees below horizontal and ends forty-five degrees above horizontal whereby this unit has the same lifting capacity at the extreme height as it has at the extreme lowered position.

When the unit is used as a skidding tractor, the fair lead is used to hoist one end of the log in the air. As will be readily seen in FIGURE 2, the main hoist cylin der 64 is out of the way of the end of the log which allows freedom of movement of the end of the log which does not come into contact with the cylinders especially when negotiating a turn. By using two power pumps, the load can be raised and simultaneously extended forwardly or backwa-rdly or the load can be lowered and simultaneously extended forwardly or backwardly thus enabling the operator to raise and reach at the same time while getting a full load on each cycle.

The various pivot shafts, pins or trunnions as well as the various lift arms, attaching lugs and the like may be constructed in any suitable shape, size and configuration for providing sufficient strength and ruggedness to withstand the forces normally encountered in the operation for which the invention is intended. Also, the specific shapes, configurations and strength requirements of the various lift arms including the extension arms and main lift arms as well as the tilting load assembly may be varied and constructed of conventional frame structures secured together in any suitable means such as by welding or the like to form the desired shape and configuration of structural elements.

Various reinforcements gussets may be provided where desired and suitable trunnions, bushings or bearings may be provided where deemed necessary and suitable lubrication fittings may be provided as deemed necessary.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.

What is claimed as new is as follows:

1. A load handling apparatus comprising a frame, an extension arm disposed substantially vertically and hav ing the lower end pivotally attached to said frame, means interconnecting the frame and the extension arm for moving the extension arm about the pivot axis at the lower end of the extension arm between positions on both sides of a vertical plane passing through the axis in parallel relation thereto, a main lift arm pivotally attached to the outer end of said extension arm, means interconnecting the extension arm and the main lift arm intermediate the ends thereof for pivoting the lift arm in relation to the extension arm, and load engaging means at the outer end of the main lift arm whereby the load engaging means may be moved vertically and simultaneously moved inwardly and outwardly in relation to the frame by pivoting the extension arm in relation to the frame and pivoting the main lift arm in relation to the extension arm, said means interconnecting the extension arm and main lift arm intermediate the ends thereof including a fluid pressure operated piston and cylinder assembly having the end of the piston rod pivotally attached to the extension arm intermediate the ends thereof, said cylinder having the inner end thereof pivotally attached to the lift arm intermediate the ends thereof whereby the lift arm may retract to a position substantially alongside of the lift arm and be extended to an upper position in which the cylinder extends upwardly in an angular direction for orientating the free end of the cylinder in an out-ofthe-Way position to enable a skidding cable to be entrained over a pulley on the lift arm for skidding a log under the lift arm without the log interfering with the cylinder when negotiating turns.

2. The structure as defined in claim 1 wherein said means interconnecting the frame and the extension arm includes a fluid pressure operated piston and cylinder assembly interconnecting the frame and a point on the extension arm intermediate the ends thereof and extending from the extension arm in opposite relation to the means interconnecting the extension arm and lift arm.

3. A log loading and skidding device comprising a mobile frame, a pair of extension arms pivotally attached to said frame adjacent the opposite side edges thereof for swinging movement in a vertical fore and aft plane, bydraulic piston and cylinder assemblies interconnecting the extension arms and the frame for pivoting the extension arms, a pair of main lift arms pivotally connected to the outer end of the extension arms, piston and cylinder assembly interconnecting the extension arms and the main lift arms in spaced relation to the pivotal connection there-between for swinging the lift arms in a vertical plane simultaneously with or independently of fore and aft swinging movement of the extension arms to both sides of a vertical plane intersecting the frame for varying the vertical and longitudinal orientation of the lift arms, and log gripping means on the outer ends of the lift arms for grasping a plurality of logs, said piston and cylinder assembly interconnecting the lift arms and extension arms including a piston rod pivotally connected to the extension arms, a cylinder telescopically receiving the piston rod, the end of said cylinder adjacent said extension arm being pivotally connected to said main lift arm, a pulley mounted on said lift arms, a log skidding cable entrained over the pulley and extending downwardly therefrom to support a log with the cylinder being orientated in an outof-the-way position when using the mobile frame as a log skidding device.

4. A log loading and skidding apparatus comprising a mobile frame, extension arm means pivotally attached to said mobile frame at a lower end with the upper end of the extension arm means being movable to both sides of a vertical plane intersecting said frame, power operated means interconnecting said frame and extension arm means for swinging the extension arm means about the pivotal connection between the lower end of the extension arm means and the frame, lift arm means pivotally attached to the upper end of said extension arm means, power operated means interconnecting the extension arm means and the lift arm means intermediate the ends thereof respectively for swinging the lift arm means about an axis at the upper end of the extension arm means, load engaging means pivotally mounted on the outer end of the lift arm means remote to the connection between the lift arm means and extension arm means, the means interconnecting the lift arm means and extension arm means having a point of connection with the lift arm means movable to a point of adjacency with the point of connection between the interconnecting means with the extension arm means and inwardly of the confines of the frame, said means interconnecting the extension arm means and lift arm means including a piston and cylinder arrangement having a piston rod pivotally attached to the extension arm means intermediate the ends thereof and a cylinder telescopically receiving the piston rod and having the inner end thereof pivotally attached to the lift arm means intermediate the ends thereof to orientate the major portion of the cylinder above the lift arm means when the lift arm means is orientated in a generally horizontal position, a log skidding pulley and cable means supported from the lift arm means thus enabling the end of a log to be suspended under the lift arm means during a skidding operation Without the log causing damage to the cylinder and piston rod especially when turning corners with the apparatus.

5. The apparatus as defined .in claim 4 wherein said extension arm means is swingable to both sides of a vertical plane passing through the pivotal connection between the extension arm means and the frame, said means interconnecting the frame and extension arm means including a power operated piston and cylinder assembly interconnecting the frame and an intermediate portion of the extension arm means and extending to the opposite side of the extension arm means from the lift arm means.

References Cited by the Examiner UNITED STATES PATENTS 2,385,512 9/1945 Heath 214140 2,801,012 7/1957 Lederer 214-138 2,820,555 1/1958 Lessrnann 214140 2,958,434 11/1960 Wagner 214-147 X 3,166,205 1/1965 Symmank 214138 HUGO O. SCHULZ, Primary Examiner.

Claims (1)

1. A LOAD HANDLING APPARATUS COMPRISING A FRAME, AN EXTENSION ARM DISPOSED SUBSTANTIALLY VERTICALLY AND HAVING THE LOWER END PIVOTALLY ATTACHED TO SAID FRAME, MEANS INTERCONNECTING THE FRAME AND THE EXTENSION ARM FOR MOVING THE EXTENSION ARM ABOUT THE PIVOT AXIS AT THE LOWER END OF THE EXTENSION ARM BETWEEN POSITIONS ON BOTH SIDES OF A VERTICAL PLANE PASSING THROUGH THE AXIS IN PARALLEL RELATION THERETO, A MAIN LIFT ARM PIVOTALLY ATTACHED TO THE OUTER END OF SAID EXTENSION ARM, MEANS INTERCONNECTING THE EXTENSION ARM AND THE MAIN LIFT ARM INTERMEDIATE THE ENDS THEREOF FOR PIVOTING THE LIFT ARM IN RELATION TO THE EXTENSION ARM, AND LOAD ENGAGING MEANS AT THE OUTER END OF THE MAIN LIFT ARM WHEREBY THE LOAD ENGAGING MEANS MAY BE MOVED VERTICALLY AND SIMULTANEOUSLY MOVED INWARDLY AND OUTWARDLY IN RELATION TO THE FRAME AND PIVOTING THE EXTENSION ARM IN RELATION TO THE FRAME AND PIVOTING THE MAIN LIFT ARM IN RELATION TO THE EXTENSION ARM, SAID MEANS INTERCONNECTING THE EXTENSION ARM AND MAIN LIFT ARM INTERMEDIATE THE ENDS THEREOF INCLUDING A FLUID PRESSURE OPERATED PISTON AND CYLINDER ASSEMBLY HAVING THE END OF PISTON ROD PIVOTALLY ATTACHED TO THE EXTENSION ARM INTERMEDIATE THE ENDS THEREOF, SAID CYLINDER HAVING THE INNER END THEREOF PIVOTALLY ATTACHED TO THE LIFT ARM INTERMEDIATE THE ENDS THEREOF WHEREBY THE LIFT ARM MAY RETRACT TO A POSITION SUBSTANTIALLY ALONGSIDE OF THE LIFT ARM AND BE EXTENDED TO AN UPPER POSITION IN WHICH THE CYLINDER EXTENDS UPWARDLY IN AN ANGULAR DIRECTION FOR ORIENTATING THE FREE END OF THE CYLINDER IN AN OUT-OFTHE-WAY POSITION TO ENABLE A SKIDDING CABLE TO BE ENTRAINED OVER A PULLEY ON THE LIFT ARM FOR SKIDDING A LOG UNDER THE LIFT ARM WITHOUT THE LOG INTEREFERING WITH THE CYLINDER WHEN NEGOTIATING TURNS.

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