Abstract:
A control handle support and valve linkage assembly for use in a lift truck or like vehicle is provided. The assembly includes a first stationary bracket and a second bracket that pivots relative to the first bracket. At least one, and preferably an array of control handles are coupled to the second bracket. A seat deck on the lift truck includes an actuator for engaging a member projecting from the second bracket. When the seat deck is in the closed position, the second bracket is kept in a first, retracted position, and hence, the control handle(s) are kept close to and within the comfortable reach of an operator seated in the adjacent seat. Then, when the seat deck is opened, such as when the operator desires to access a battery compartment or the like, the second bracket, and hence, the control handle(s) automatically and simultaneously pivot or rotate relative to the first stationary bracket. This moves the control handles out of the path of travel of the seat deck to avoid creating any interference. A linkage is also provided for linking each control handle to a valve and a corresponding switch. Together, the valve and switch regulate fluid flow to control one or more aspects of the operation of a carrying assembly or like structure associated with the lift truck.

Description:
This application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/151,118, filed Aug. 27, 1999, entitled “Control valve linkage assembly,” which is incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     The present invention relates generally to vehicle control and, more particularly, to an improved assembly for both supporting one or more control handles in a lift truck such that interference with a movable deck or like structure is avoided and linking the control handles to valves for controlling the operation of a carrying assembly forming a part of the lift truck. 
     BACKGROUND OF THE INVENTION 
     In a conventional lift truck, an array of control handles are provided for controlling the flow of hydraulic fluid typically used to raise, rotate, or otherwise move a portion of the carrying or lifting apparatus (i.e., the mast and forks and accompanying structures). These control handles should be conveniently located within the operator compartment for easy, comfortable access. Of course, providing control handles that are securely and reliably linked to the corresponding valve(s) for controlling the flow of hydraulic fluid is also an important consideration, as is minimizing the number of parts required and reducing the overall complexity. 
     Typically, a lift truck is provided with a compartment covered by a movable deck that carries an operator&#39;s seat. This compartment usually contains components responsible for providing power to the lift truck, including the battery. In such an arrangement, positioning the control handles comfortably within the reach of the operator generally places them immediately over the seat deck or other movable structure forming a part of the lift truck base. As a result of this placement, the control handles create an obstacle to removing the deck for gaining access to the adjacent battery compartment or the like. 
     In one prior art truck, before the seat deck can be opened to gain access into the battery compartment, a control handle release mechanism must be actuated followed by the manual pivoting of the control handles away from the seat deck. Such an arrangement is disadvantageous as additional time and effort are required to reposition the control handles prior to opening the seat deck. Further, it requires that an operator be positioned on a side of the truck to which the control handles are located when opening the seat deck. Typically, this side of the truck is opposite to the side that is used when exiting or entering the operator&#39;s compartment, resulting in the operator walking around the truck before and/or after opening the seat deck. 
     In another prior art truck, the control handles, structure which couples the handles to corresponding valves and a front cover, automatically pivot away from the seat deck when the deck is opened. A costly pivoting plate must be provided for mounting the handles, the coupling structure and the front cover. It is also noted that the plate has a low pivot position. Consequently, substantial clearance is required between the floorplate and the front cover, to allow the plate, the control handles, the coupling structure and the front cover to rotate away from the seat deck when the seat deck is raised. This clearance allows the ingress of foreign material onto the hydraulic valves, which is undesirable. Further, the shape of the front cover restricts easy ingress into and egress from the operator&#39;s compartment. 
     Thus, a need is identified for an improved manner for supporting one or more control handles within the comfortable reach of the operator, while at the same time avoiding the creation of interference with removable structures on the lift truck, such as the deck carrying the operator&#39;s seat. 
     SUMMARY OF THE INVENTION 
     In accordance with a first aspect of the invention, a control handle support and valve linkage apparatus for mounting adjacent a movable deck on a lift truck is provided. The apparatus includes a first stationary bracket and a second bracket in engagement with the first bracket. At least one control handle assembly is coupled to the second bracket, and preferably positioned for easy access by the lift truck operator when seated in the operator&#39;s compartment. The second bracket is movable relative to the first bracket between a first retracted position and a second non-interfering position, with the second bracket being in the first position when the deck is in a closed position and in the second position when the deck is moved to an open position. Accordingly, when the seat deck is opened, the second bracket simultaneously pivots to move the control handle assemblies out of the way. This simultaneous pivoting action avoids creating any interference between the control handle assemblies and the seat deck as it is lifted. Further, the pivoting action avoids any interference between the handle assemblies and the battery when the battery is lifted for removal. 
     In one embodiment, the control handle support and valve linkage apparatus includes a spring for biasing the second bracket relative to the first bracket. The biasing force supplied by this spring allows the second bracket to pivot from the first to the second position when the deck is opened. Preferably, the second bracket rotates through an angle from about 15 degrees to about 90 degrees in moving from the first position to the second position, and most preferably through an angle of about 22°. To provide the desired simultaneous pivoting action and relative movement, the second bracket further comprises a projecting member and the deck includes an actuator. When the deck is moving from the open to the closed position, this actuator engages the projecting member to overcome the spring biasing force and pivot the second bracket to the first position. In a most preferred embodiment, the projecting member is a substantially cylindrical rod and the actuator includes a C-shaped recess for engaging the rod. The deck preferably is at least a portion of a seat deck forming a part of a base portion of the lift truck. 
     In accordance with a second aspect of the present invention, a control handle support and valve linkage assembly is provided for mounting adjacent to a movable deck on a lift truck having a carrying assembly. The control handle support and valve linkage assembly comprises a first stationary bracket, at least one valve for controlling fluid flow to and away from the carrying assembly on the lift truck, a second bracket engaging the first bracket, at least one control handle assembly coupled to the second bracket, structure for coupling the at least one control handle assembly to the at least one valve, and at least one switch coupled directly to the at least one valve and operable to control fluid flow to the at least one valve. The second bracket is movable relative to the first bracket between a first position when the deck is closed and a second position when the deck is open. Preferably, the coupling structure does not pivot or otherwise move when the second bracket moves between its first and second positions. 
     Preferably, the control handle support and valve linkage assembly further includes a stationary cover. In one preferred embodiment, the cover has a generally planar outer surface. Advantageously, this planar outer surface does not interfere with the ingress to and egress from the operator&#39;s compartment of the lift truck. 
     In one embodiment, the second bracket rotates relative to the first bracket through an angle of from about 15 degrees to about 90 degrees in moving from the first position to the second position. The second bracket may also rotate through other angular ranges including all ranges subsumed within the range of from about 15 degrees to about 90 degrees. Also, the coupling structure comprises at least one link and at least one cam. The at least one link is coupled to the at least one control handle assembly and the at least one cam. The at least one cam is further coupled to the at least one valve, which preferably comprises a spool valve. 
     Most preferably, first and second control handle assemblies are provided as part of the control valve linkage assembly. A spring is also provided for biasing the second bracket relative to the first bracket such that the second bracket pivots from the first position to the second position when the deck is moved to the open position. The second bracket includes a projecting member and the deck further comprises an actuator for engaging the projecting member to pivot the second bracket to the first position when the deck is moved to a closed position. In one particular embodiment, the projecting member is a substantially cylindrical rod and the actuator includes a C-shaped recess for engaging the rod. The deck is a seat deck forming a part of a base portion of the lift truck. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an overall perspective view of a lift truck; 
     FIG. 2 is a side elevational view of the lift truck of FIG. 1; 
     FIG. 3 a  is the upper portion of an exploded view showing the control handle support and valve linkage assembly of the present invention; 
     FIG. 3 b  is the lower portion of an exploded view showing the control handle support and valve linkage assembly of the present invention; 
     FIG. 3 c  is a plan view of the first stationary bracket illustrated in FIG. 3 a;    
     FIG. 4 is an enlarged, partially cutaway view of the upper portion of the control handle support and valve linkage assembly of the present invention, with a portion of the cover cutaway to show the connection between the bellcrank secured to each control handle and the corresponding coupling structure; 
     FIG. 5 a  is a partially cross-sectional, partially cutaway side view showing the second bracket in a first position and taken along view line  5   a — 5   a  in FIG. 4; 
     FIG. 5 b  is similar to FIG. 5 a,  but shows the bracket pivoted to a second position upon the lifting of the seat deck forming a part of the lift truck base; and 
     FIGS. 6-9 are schematic views, each showing the cam associated with each control handle assembly for actuating a switch that controls the flow of fluid through a corresponding valve. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Reference is now made to FIGS. 1 and 2, which illustrate a fork lift truck  10  including a control handle support and valve linkage assembly  20  constructed in accordance with the present invention. The truck  10  includes a body  12  housing a battery  140  (see phantom view in FIGS. 5 a  and  5   b ) for supplying power to a traction motor (not shown) connected to a pair of front drive wheels  12   a  (only one shown in FIGS. 1 and 2) and to one or more hydraulic motors (not shown) supplying hydraulic fluid to several different systems, such as mast and fork hydraulic cylinders. The traction motor and the drive wheels  12   a  define a drive mechanism for effecting movement of the truck  10 . An operator&#39;s compartment  14  in the body  12  is provided with a steering wheel  16  for controlling the direction of travel of the truck  10  and control handles  30 - 33  (see FIG. 3 a ) are provided for controlling fork height, tilt, side shift and fork rotation. The steering wheel  16  is coupled via conventional apparatus to a pair of steerable rear wheels  12   b  (only one shown in FIG.  2 ). 
     As best shown in FIG. 1, a pair of forks  40  are mounted on a fork carriage mechanism  42  that includes a fork carriage  44  and a load back rest  46 . The forks  40  are coupled to the fork carriage  44  which, in turn, is coupled to an extensible mast assembly  50 . The load back rest  46  is coupled to the fork carriage  44 . The mast assembly  50  includes a fixed lower mast member  52  and nested first and second movable mast members  54  and  56 . The lower mast member  52  is fixedly coupled to the body  12 , while the second movable mast member  56  is coupled directly to the fork carriage  44 . The fork carriage mechanism  42  and the mast assembly  50  together define a fork carrying assembly. The mast assembly  50  includes a plurality of hydraulic cylinders (not shown) for effecting vertical movement of the mast members  54  and  56 . Further, hydraulic cylinders (not shown) are coupled to the body  12  and the mast assembly  50  for tilting mast members  52 ,  54  and  56  toward and away from the truck  10  about a substantially horizontal axis. Additional hydraulic apparatus (not shown) is provided between the mast assembly  50  and the carriage mechanism  42  for moving the carriage mechanism  42  and the forks  40  from side to side about a vertical axis A 1 , as well as rotating the carriage mechanism  42  and the forks  40  about an axis of rotation A 2  (see FIG.  2 ). 
     Referring now to FIG. 3 a,  the control handle support and valve linkage assembly  20  includes the control handles  30 - 33 . The assembly  20  also includes a first generally horizontal stationary bracket  15  and a second, rotatable bracket  11  coupled to the first bracket  15 . The first bracket  15  is fixedly mounted to the body  12  of the lift truck  10  below a seat deck  13  (see FIG. 4) and includes a two opposed, inwardly projecting coaxial cantilevered pins  15   a  and  15   d  (see FIG. 3 c ) extending inwardly from first and second sidewalls  15   b  and  15   c  of the first bracket  15 . The second rotatable bracket  11  includes first and second recesses  11   a  and  11   b  for receiving each of the respective opposing pins  15   a  and  15   d  on the first bracket  15 . Pin  15   d  has a first portion having a first diameter and a second portion having a second diameter which is greater than the first diameter. The second recess  11   b  receives the first portion of the pin  15   d.  When assembled, the second bracket  11  is thus rotatably mounted to the first bracket  15  by virtue of this connection. A spring washer  14   a  is also fitted over pin  15   a  and a spring washer  16   b  is fitted over pin  15   d  to frictionally engage the corresponding sidewalls  15   b,    15   c  of the bracket  15 . 
     The pin  15   d  further receives a flat washer  17  and a torsion spring  18 . The spring  18  is received on the second portion of the pin  15   d.  The pin  15   d  serves as a hub for the spring  18  that causes the second bracket  11  to pivot relative to the first bracket  15 . More specifically, in the preferred embodiment, a first leg  18   a  of the spring  18  projects downwardly and is received in a recess  150  formed in a cross bar  15   e  of the bracket  15 , while a second leg  18   b  of the spring  18  also projects downwardly and is captured in a C-shaped recess  11   c  provided in the second bracket  11 . As outlined further in the description that follows, the spring  18  effects pivotable movement of the second bracket  11  relative to the first bracket  15  when the seat deck  13  is opened, thereby serving to simultaneously and automatically move the control handles  30 - 33  out of the way to avoid creating interference. 
     The first control handle  30  is mounted to a first bellcrank  22  via at least one, and preferably a pair of screws  21 . The first handle  30  and the first bellcrank  22  comprise a first handle assembly. The second, third and fourth control handles  31 - 33  are similarly coupled to second, third and fourth bellcranks  27 - 29  via pairs of screws  21 . The control handles  31 - 33  and the bellcranks  27 - 29  comprise second, third and fourth handle assemblies. The term “handle assembly,” as used herein, is also intended to cover a handle when used without accompanying structure such as a bellcrank, or an integral handle/bellcrank unit. 
     Each bellcrank  22  and  27 - 29  is provided with a bore  23 . Two bushings  24  are press-fit into opposing ends of each bore  23 . A shaft  14   b  passes through each set of two bushings  24  and, hence, through the bores  23  in the bellcranks  22  and  27 - 29 . The shaft  14   b  also passes through bushings  24  press-fit into bores  11   d  and  11   e  in the second bracket  11 . The bellcranks  22  and  27 - 29  and the bushings  24  are rotatable about the shaft  14   b,  and the shaft  14   b  is rotatable relative to the bracket  11 . Spring washers  25  and flatwashers  26  are captured in place by a collar-like spacer  26   a  connected to the shaft  14   b  using a transverse pin  26   b.  The pin  26   b  extends through openings in the spacer  26   a  and shaft  14   b  (the opening in the shaft is not shown). 
     The first ends  19   a  of first, second, third and fourth links  19  are coupled to the first, second, third and fourth bellcranks  22  and  27 - 29  via retainer pins  23   a  and captivated by cotter pins  23   b,  see FIG. 3 a.  The opposite, or second ends  19   b  of the first, second, third and fourth links  19  are separately coupled to first ends  60   a  of cams  60 , see FIG. 3 b.  A separate retainer pin  23   a  and cotter pin  23   b  (only one of each is shown in FIG. 3 b ) is provided for coupling each link second end  19   b  to its corresponding cam  60 . The second end  60   b  of each cam  60  includes a threaded recess (not numbered) for receiving a threaded upper portion  70   a  of a spool  70  of a corresponding first, second, third or fourth spool valve  72   a - 72   d.  Hence, pivotal movement of the control handles  30 - 33  and coupled bellcranks  22  and  27 - 29  about shaft  14   b  moves the links  19 , cams  60  and spools  70  generally in a vertical direction. 
     First, second, third and fourth switches  80   a - 80   d  are directly coupled to each of the respective spool valves  72   a - 72   d.  These switches  80   a - 80   d  are preferably conventional snap-action switches. The switches  80   a - 80   d  are coupled to the spool valves  72   a - 72   d  by brackets  82 , spacer plates  84 , insulators  84   a,  retainer plates  86 , and bolts  88 . The retainer plates  86  are provided with tapped holes (not shown) for threadedly receiving the bolts  88 . For each switch  80   a - 80   d,  a spacer plate  84  and an insulator  84   a  are positioned on opposing sides of the switch. Further, one or more bolts pass through openings provided in the spacer plate  84 , openings in the insulator  84   a,  openings in the switch and openings in the bracket  82  and threadedly engage openings in the retainer plate  86 , which is positioned on a side of the bracket opposite to the side to which the spacer plate, insulator and switch are positioned, for securing the switch to its bracket  82 . The brackets  82  are coupled to the valves  72   a - 72   d  via bolts  73 . 
     Referring now to FIGS. 1 and 4, a conventional latch  13   a,  coupled to the seat deck  13 , is provided for releasably locking the seat deck  13  to a base portion  12   c  of the body  12  of the lift truck. The seat deck  13  is provided with an actuator, which in the preferred embodiment is a hook  130  having a C-shaped recess (see FIGS. 5 a  and  5   b ). The hook  130  is fixedly connected to the seat deck  13  such that it does not move relative to the seat deck  13  and is spaced horizontally from the latch  13   a,  see FIG.  4 . 
     The hook  130  engages a cantilevered pin  11   f  projecting outwardly from the second bracket  11  when the seat deck  13  is in its “down” position so as to maintain the bias spring  18  and second bracket  11  in a first position P 1  relative to the first bracket  15 , see FIG. 5 a.  When the second bracket  11  is in its first position, generally planar plate portion  11   g  of the bracket  11  is located in a substantially horizontal plane, and the legs  18   a,    18   b  of the spring  18 , which both project downwardly in this preferred embodiment, are moved closer to each other. The seat deck  13  is shown in its “down” position in FIGS. 1,  2 ,  4  and  5   a  (note dashed line outline of spring  18 ). 
     When the latch  13   a  on the seat deck  13  is manually released (see action arrow C in FIG. 4) and the seat deck  13  is pivoted upward (see action arrow A in FIG. 5 b ), the hook  130  disengages pin  11   f.  An operator may easily release the latch  13   a  when positioned on either side of the truck. Upon removing the substantially downward force of seat deck  13  on pin  11   f,  the spring expands such that leg  18   b  moves away from leg  18   a.  This causes the bracket  11  to rotate (counterclockwise, or in the direction of action arrow B as viewed in FIG. 5 b ) about pins  15   a  and  15   d  on the bracket  15  to a second position P 2 . When the bracket  11  moves to its second position, the plate portion  11   g  rotates through an angle of about 22° from its substantially horizontal first position (compare FIGS. 5 a  and  5   b ). Despite this reference to a most preferred degree of angular rotation, it is also contemplated that the plate portion  11   g  could rotate through other angles which fall within the range of from about 15° to about 90° from the first position. 
     As should be appreciated from viewing FIG. 5 b,  the control handles  30 - 33  and bellcranks  22  and  27 - 29  rotate with the bracket  11  and, hence, move away from the seat deck  13 . The links  19 , however, do not move relative to the bracket  15  during rotation of the bracket  11  as the bellcranks  22  and  27 - 29  pivot about their retainer pins  23   a  without displacing the links  19 . It is noted that retainer pins  23   a  are substantially coaxial with pins  15   a  and  15   d.  The seat deck  13  may then continue to freely pivoted upwardly, such as to permit the operator to access the battery  140  or other component without contacting or otherwise interfering with the control handles  30 - 33 . Then, when the seat deck  13  moves towards a closed position (i.e., rotates downwardly), and after it has moved past upper ends  30   a - 33   a  of the handles  30 - 33 , the hook on the seat deck  13  reengages the pin  11   f.  This engagement causes the bracket  11  to rotate against the bias of the spring  18  to its first position P 1 . The locking of the latch  13   a  maintains the bracket  11  in its first position P 1 . 
     With reference back to FIG. 3 a,  a stop  112  is preferably provided in this most preferred embodiment to limit the rotational movement effected by the spring  18  of the second bracket  11  relative to first bracket  15 . This stop  112  comprises, for example, a bolt  112   a  threadedly received in a tapped opening  11   h  in the bracket  11 . Rotational movement of the second bracket  11  relative to the first bracket  15  stops when the head of the bolt  112   a  engages the rear wall of first bracket  15 . A nut  112   b  is also provided to lock the bolt  112   a  in position relative to the bracket  11 , as well as to allow for height adjustments. 
     As shown in FIGS. 1,  2 ,  4 ,  5   a,  and  5   b,  a removable cover  100  is provided over bellcranks  22  and  27 - 29 , links  19 , cams  60 , switches  80   a - 80   d  and valves  72   a - 72   d,  but includes slots (not numbered) that allow the lower end portion of the control handles  30 - 33  to pass and engage the corresponding bellcranks  22 ,  27 - 29 . This cover  100  is fixedly coupled to the base portion  12   c  of the body  12  and, thus, remains stationary during movement of the bracket  11  between its first and second positions P 1 , P 2 . Due to the compact nature of the brackets  11  and  15  and the mounting of the switches  80   a - 80   d  directly to the valves  72   a - 72   d,  the cover  100  has a narrow profile and includes a generally planar outer face  100   a.  Advantageously, this prevents the cover  100  from interfering with the operator&#39;s ingress into and egress from the compartment  14 . 
     In operating the control valve linkage assembly  20  generally, the first control handle  30  is rotated toward the operator causing the spool  70  of the valve  72   a  and its associated cam  60  to be raised. Upward movement of the spool  70  past its centered position opens the valve  72   a  such that hydraulic fluid is permitted to travel to the hydraulic cylinders (not shown) of the mast assembly  50 . The corresponding upward movement of the cam  60  (see action arrow D in FIG. 6) causes a roller arm  81   a  of the switch  80   a  to move out of a first groove  60   c  in the cam  60 , which results in the actuation of the first switch  80   a.  Actuation of the switch  80   a  causes a hydraulic pump apparatus (not shown) to supply hydraulic fluid under pressure through the valve  72   a  to the mast assembly  50 . Movement of the control handle  30  away from the operator and to the home or centered position results in the roller arm  81   a  moving back into the groove  60   c  such that the switch  80   a  is no longer actuated. Further movement of the control handle  30  away from the operator results in the valve  72   a  opening to allow hydraulic fluid to drain from the hydraulic cylinders of the mast assembly  50  to a hydraulic reservoir (not shown). As should be appreciated, movement of the control handle  30  away from the operator and beyond its centered position does not result in the switch  80   a  being actuated. Hence, the hydraulic pump apparatus is not actuated when the control handle  30  is moved away from the operator beyond its centered position. 
     To tilt the mast assembly  50  and the forks  40 , the second control to handle  31  is rotated toward or away from the operator causing the spool  70  of the valve  72   b  and its associated cam  60  to be raised or lowered. Movement of the spool  70  past its centered position opens the valve  72   b  such that hydraulic fluid is permitted to travel between the hydraulic cylinders (not shown) coupled to the body  12  and the mast assembly  50  and a hydraulic pump apparatus (not shown) and a hydraulic reservoir (not shown) for effecting tilting movement of the mast members  52 ,  54  and  56  toward and away from the operator. Movement of the cam  60  from its centered position causes a roller arm  81   b  of the switch  80   b  to move out of a second groove  60   d  in the cam  60  resulting in actuation of the second switch  80   b  (see FIG.  7 ). Actuation of the switch  80   b  results in the hydraulic pump apparatus supplying hydraulic fluid under pressure through the valve  72   b  to the hydraulic cylinders (not shown) coupled to the body  12  and the mast assembly  50 . 
     To move the carriage mechanism  42  and the forks  40  from side to side about the vertical axis A 1 , the third control handle  32  is rotated toward or away from the operator causing the spool  70  of the valve  72   c  and its associated cam  60  to be raised or lowered. Movement of the spool  70  past its centered position opens the valve  72   c  such that hydraulic fluid is permitted to travel between appropriate hydraulic cylinders (not shown) provided between the mast assembly  50  and the carriage mechanism  42  and a hydraulic pump apparatus (not shown) and a hydraulic reservoir (not shown) to effect side to side movement of the carriage mechanism  42  and the forks  40 . Movement of the cam  60  from its centered position causes a roller arm  81   a  of the switch  80   c  to move out of a second groove  60   d  in the cam  60  resulting in actuation of the third switch  80   c  (see FIG.  8 ). Actuation of the switch  80   c  results in the hydraulic pump apparatus supplying hydraulic fluid under pressure through the valve  72   c  to hydraulic cylinders provided between the mast assembly  50  and the carriage mechanism  42 . 
     To rotate the carriage mechanism  42  and the forks  40  about an axis of rotation A 2 , the fourth control handle  33  is rotated toward or away from the operator causing the spool  70  of the valve  72   d  and its associated cam  60  to be raised or lowered. Movement of the spool  70  past its centered position opens the valve  72   d  such that hydraulic fluid is permitted to travel between appropriate hydraulic cylinders (not shown) provided between the mast assembly  50  and the carriage mechanism  42  and a hydraulic pump apparatus (not shown) and a hydraulic reservoir (not shown) to effect rotational movement of the carriage mechanism  42  and the forks  40 . Movement of the cam  60  from its centered position causes a roller arm  81   a  of the switch  80   d  to move out of a second groove  60   d  in the cam  60  resulting in actuation of the fourth switch  80   d  (see FIG.  9 ). Actuation of the switch  80   d  results in the hydraulic pump apparatus supplying hydraulic fluid under pressure through the valve  72   d  to hydraulic cylinders provided between the mast assembly  50  and the carriage mechanism  42 . 
     It is further contemplated that the control valve linkage assembly may include only first, second and third control handles (not shown), such as for controlling fork height, side shift, and tilt. Moreover, it is also possible to provide only two control handles (not shown), such as for controlling fork height and tilt. It is additionally contemplated that control handles  32  and  33  may be employed to control options other than fork side shift and fork rotation. For example, the handles  32  and  33  may be used to control the following functions: fork spread (forks traverse left and right symmetrically about the center of the truck); load stabilizer (a pad comes down on the load to keep it from tipping/shifting); push/pull (a device extends out, clamps on a bottom sheet (e.g., cardboard or plastic) and pulls the sheet onto the forks/pushes to remove); clamp (device that clamps the load from the sides); rotate (device that clamps and rotates (e.g., barrels, rolls of paper, etc.) left and right); and upender (device that provides the ability to rotate a load forward and backward (e.g., used for pouring)), or any like function where control of a mechanism associated with a lift truck or other vehicle is provided through the actuation of switches or the like. 
     The foregoing description of preferred embodiments of the present invention have been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Obvious modifications or variations are possible in light of the above teachings. The embodiments were chosen and described to provide the best illustration of the principles of the invention and its practical application to thereby enable one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. All such modifications and variations are within the scope of the invention as determined by the appended claims when interpreted in accordance with the breadth to which they are fairly, legally and equitably entitled.