Patent Publication Number: US-2009238026-A1

Title: In-cab control system for a front discharge concrete truck

Description:
BACKGROUND 
     1. Field of the Invention 
     The present invention relates to front discharge concrete trucks and, particularly, to control systems for front discharge concrete trucks. 
     2. Description of the Related Art 
     Front discharge concrete trucks are utilized to mix, deliver, discharge, and place concrete at a jobsite. In order to facilitate the proper placement of the concrete, the operator of the concrete truck is provided with a series of controls that operate various functions of the truck. For example, in order to properly place the concrete, the operator may be provided with controls for the discharge of concrete, movement of the discharge chute, and movement of the truck itself. Specifically, in order to control the placement of the concrete, the operate will need to actuate foot petals that control the throttle of the truck&#39;s engine, rotate a steering wheel to alter the direction of the truck, actuate a gear shift that controls the trucks transmission, and actuate a chute control to direct movement of the discharge chute. 
     However, due to the number of controls that must be actuated by the operator during the placement of concrete at a jobsite, the operator is unable to substantially simultaneously actuate all of the controls. Thus, the operator is forced to release at least one of the controls in favor of actuating another of the controls. For example, since each of the steering wheel, gear shift, and chute control are hand operated, the operator of the truck will at any given time have a hand removed from at least one of these three controls. As a result, the operator is incapable of substantially concurrently actuating all of the controls necessary to efficiently place concrete at a jobsite. As a result, the time required to properly place a load of concrete at a jobsite is increased and the ability of the operator to effectively place the concrete is hampered. 
     What is needed is an improvement over the foregoing. 
     SUMMARY OF THE INVENTION 
     The present invention relates to front discharge concrete trucks and, particularly, to control systems for use with the same. In one exemplary embodiment, the control system of the present invention includes a joystick positioned within the cab of a concrete truck. In one embodiment, the joystick connects to both a secondary shift selector and a chute controller. The secondary shift selector is connected to the truck&#39;s transmission. By actuating the secondary shift selector, the operator of the truck is capable of placing the truck&#39;s transmission in one of a forward condition, a reverse condition, and a neutral condition, without removing the driver&#39;s hand from the joystick. Similarly, the chute controller is connected to a discharge chute of the truck to direct the placement of concrete being offloaded from the truck. Thus, substantially concurrently with placing the transmission into one of a forward condition, a reverse condition and a neutral condition, the operator may actuate the joystick to correspondingly actuate the position of the discharge chute via the chute controller. 
     Advantageously, by providing the operator with a joystick capable of controlling both the truck&#39;s transmission and the position of the discharge chute, the operator may place one hand on the joystick and utilize the other hand to steer the vehicle while substantially simultaneously utilizing the operator&#39;s feet to control the engine&#39;s throttle and/or brake. This allows the operator to more effectively place concrete at a desired location on a jobsite by providing the operator with all the controls necessary for affecting the placement of concrete without the need to reposition a hand and/or foot during the same. 
     In another exemplary embodiment, a drum condition selector is positioned on the joystick. By actuating the drum condition selector, a drum, which is positioned on a chassis of the concrete truck and which holds the concrete therein, is changed from one of a discharge condition and a charge condition to the other of the discharge condition and the charge condition. Specifically, when the drum is in the charge condition, the drum rotates in a direction that causes the concrete contained therein to remain within the drum. In contrast, when the drum is in the discharge condition, the direction of rotation of the drum is reversed from the charge condition and the concrete contained within the drum will begin to exit through a discharge opening and enter the discharge chute. With the concrete in this position, the operator may control placement of the concrete by actuating the joystick which, as described above, is connected to a chute controller. 
     In this embodiment, the operator is capable of substantially simultaneously changing the condition of the vehicle&#39;s transmission, the direction of rotation of the drum, and position of the discharge chute to properly place concrete at a jobsite. Advantageously, by coupling each of the chute control, drum control, and transmission control to a joystick, the need for the operator to remove their hand from the joystick to actuate any of these features is eliminated. As a result of the use of the joystick of this embodiment, in conjunction with known steering and engine throttle and brake controls, an operator is provided the access to every control necessary to facilitate the placement of concrete at a jobsite without the need to remove a hand and/or foot from any of the controls. 
     In one form thereof, the present invention provides a control device for a front discharge concrete truck. The truck includes an engine, a transmission coupled to the engine, the transmission having a forward condition, a reverse condition, and a neutral condition, a chassis supporting the engine and the transmission, a rotatable drum having a discharge opening positioned on the chassis, a chute configured to receive and direct material discharged from the drum through the discharge opening, and a cab positioned on the chassis substantially adjacent the discharge opening. The cab includes a driver&#39;s seat, a steering wheel, and a primary shift selector positioned therein, wherein the primary shift selector is actuatable to cause the transmission to enter one of the forward condition, the reverse condition, and the neutral condition and leave another of the forward condition, the reverse condition, and the neutral condition. The control device includes: a joystick positioned within the cab, the joystick moveable on at least two substantially orthogonal joystick axes; a chute controller connected to both the joystick and the chute, the chute controller operable to actuate the chute along at least two substantially orthogonal chute axes, the at least two substantially orthogonal chute axes corresponding to the at least two substantially orthogonal joystick axes, wherein actuation of the joystick along either of the at least two substantially orthogonal joystick axes results in corresponding actuation of the chute; and a secondary shift selector positioned on the joystick, the secondary shift selector connected to the transmission, wherein actuation of the secondary shift selector results in the transmission entering one of the forward condition, the reverse condition, and the neutral condition and leaving another of the forward condition, the reverse condition, and the neutral condition. 
     In another form thereof, the present invention provides a front discharge concrete truck, including: an engine; a transmission coupled to the engine, the transmission having a forward condition, a reverse condition, and a neutral condition; a chassis supporting the engine and the transmission; a rotatable drum mounted on the chassis for holding concrete, the drum having a discharge opening, a discharge condition, and a charge condition, whereby, in the discharge condition, the drum discharges concrete through the discharge opening; a chute configured to receive and direct concrete discharged from the drum through the discharge opening; a cab positioned on the chassis substantially adjacent to and below the discharge opening; a driver&#39;s seat positioned within the cab; a steering wheel positioned within the cab; a primary shift selector positioned within the cab, the primary shift selector connected to the transmission, wherein the primary shift selector is actuatable to cause the transmission to enter one of the forward condition, the reverse condition, and the neutral condition and leave another of the forward condition, the reverse condition, and the neutral condition; a joystick positioned within the cab, the joystick moveable on at least two substantially orthogonal joystick axes; a chute controller connected to both the joystick and the chute, the chute controller operable to actuate the chute along at least two substantially orthogonal chute axes, the at least two substantially orthogonal chute axes corresponding to the at least two substantially orthogonal joystick axes, wherein actuation of the joystick along either of the at least two substantially orthogonal joystick axes results in corresponding actuation of the chute; and a secondary shift selector positioned on the joystick, the secondary shift selector connected to the transmission, wherein actuation of the secondary shift selector results in the transmission entering one of the forward condition, the reverse condition, and the neutral condition and leaving another of the forward condition, the reverse condition, and the neutral condition. 
     In yet another form thereof, the present invention provides a control system for a front discharge concrete truck, the truck including an engine, a transmission coupled to the engine, the transmission having a forward condition, a reverse condition, and a neutral condition, a chassis supporting the engine and the transmission, a rotatable drum having a discharge opening positioned on the chassis, a chute configured to receive and direct material discharged from the drum through the discharge opening, and a cab positioned on the chassis substantially adjacent to the discharge opening. The cab includes a driver&#39;s seat, a steering wheel, and a primary shift selector positioned therein, wherein the primary shift selector is actuatable to cause the transmission to enter one of the forward condition, the reverse condition, and the neutral condition and leave another of the forward condition, the reverse condition, and the neutral condition. The control system including: a joystick positioned within the cab, the joystick moveable on at least two substantially orthogonal joystick axes; a chute controller electronically connected to the joystick, the chute controller operable to actuate the chute along at least two substantially orthogonal chute axes, the at least two substantially orthogonal chute axes corresponding to the at least two substantially orthogonal joystick axes, wherein actuation of the joystick along either of the at least two substantially orthogonal joystick axes results in the joystick sending an electronic signal to the chute controller causing the chute controller to correspondingly actuate the chute in accordance with the electronic signal received from the joystick; a transmission control module connected to the transmission, wherein the transmission control module actuates the transmission to enter one of the forward condition, the reverse condition, and the neutral condition and leave another of the forward condition, the reverse condition, and the neutral condition; and a secondary shift selector positioned on the joystick, the secondary shift selector electronically connected to the transmission control module, wherein actuation of the secondary shift selector results in the secondary shift selector sending an electronic signal to the transmission control module and the transmission control module actuates the transmission to enter one of the forward condition, the reverse condition, and the neutral condition and leave another of the forward condition, the reverse condition, and the neutral condition in accordance with the electronic signal received from the secondary shift selector. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention itself will be better understood by reference to the following description of an embodiment of the invention taken in conjunction with the accompanying drawings, wherein: 
         FIG. 1  is a perspective view of a front discharge concrete truck; 
         FIG. 2  is a perspective view of the interior of the cab of the front discharge concrete truck of  FIG. 1 ; 
         FIG. 3  is an enlarged, fragmentary prospective view of the cab of  FIG. 3 ; 
         FIG. 4  is a schematic depiction of a control system according to one embodiment of the present invention; 
         FIG. 5  is a perspective view of several components of the schematic of  FIG. 4  showing several connections therebetween; 
         FIG. 6A  is a front, elevational view of the joystick of the control system of  FIG. 5 ; 
         FIG. 6B  is a side, elevational view of the joystick of the control system of  FIG. 5 ; 
         FIG. 7A  is a perspective view of the electronic control module of the control system of  FIG. 5 ; 
         FIG. 7B  is a plan view of the electronic control module of the control system of  FIG. 5 ; 
         FIG. 7C  is a side, elevational view of the electronic control module of the control system of  FIG. 5  taken in the direction of line  7 C- 7 C of  FIG. 7B ; 
         FIG. 7D  is a side, elevational view of the electronic control module of the control system of  FIG. 5  taken in the direction of line  7 D- 7 D of  FIG. 7B ; 
         FIG. 8A  is perspective view of the chute controller of the control system of  FIG. 5 ; 
         FIG. 8B  is another perspective view of the chute controller of the control system of  FIG. 5 ; 
         FIG. 9  is schematic of a control system according to another exemplary embodiment; 
         FIG. 10  is schematic of a control system according to yet another exemplary embodiment; 
         FIG. 11  is schematic of a control system according to a further exemplary embodiment; 
         FIG. 12  is schematic of a control system according to another exemplary embodiment; 
         FIG. 13  is a partial plan view of an exemplary embodiment of a hydraulic chute control taken along line  13 - 13  of  FIG. 1 ; 
         FIG. 14  is a partial cross-sectional view of an exemplary embodiment of a pneumatic control; and 
         FIG. 15  is a schematic depiction of the drum control system according to an exemplary embodiment. 
     
    
    
     Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate preferred embodiments of the invention and such exemplifications are not to be construed as limiting the scope of the invention in any manner. 
     DETAILED DESCRIPTION 
     Front discharge concrete truck  10 , shown in  FIG. 1 , includes engine  12  and transmission  14  (shown schematically in  FIG. 4 ), which are supported by chassis  16 . Engine  12  may be an internal combustion engine, for example, which is operated to provide power to truck  10 . For example, operation of engine  12  delivers power to transmission  14 , which may be in one of a forward condition, a reverse condition, and a neutral condition. The power provided to transmission  14  is then transferred to axels  13  and wheels  15 , resulting in corresponding movement of truck  10 . Specifically, when transmission  14  is in the forward condition, engine  12  generates power that is transmitted to transmission  14 , and, correspondingly, axels  13  and wheels  15 , to cause truck  10  to move in a forward direction, i.e., the direction of arrow A of  FIG. 1 . Alternatively, when transmission  14  is in the reverse condition, engine  12  generates power that is transmitted to transmission  14 , and, correspondingly, axels  13  and wheels  15 , to cause truck  10  to move in a reverse direction, i.e., the direction of arrow B of  FIG. 1 . Finally, when transmission  14  is in the neutral condition, engine  12  may transmit power to transmission  14 , however no corresponding movement of truck  10  results. 
     As shown in  FIG. 1 , truck  10  also includes drum  18  mounted on chassis  16 . Drum  18  is configured to be filled with concrete for the transportation of concrete to a jobsite. Additionally, drum  18  is rotatably mounted to chassis  16 , such that drum  18  may be continually rotated along its longitudinal axis to help the concrete therein achieve the proper consistency and also to help prevent the concrete contained therein from setting. During operation of truck  10 , drum  18  is placed in one of a charge condition and a discharge condition. When drum  18  is in the charge condition, drum  18  is rotating in the charge direction and the concrete remains contained within drum  18 . In contrast, when drum  18  is in the discharge condition, drum  18  is rotated in the discharge direction, i.e., the direction opposite of the charge direction, and the concrete contained therein is discharged from drum  18  through discharge opening  20 . 
     When drum  18  is in the discharge condition and concrete is exiting drum  18  through discharge opening  20 , the concrete is directed to chute  22 . As shown in  FIG. 1 , chute  22  includes three portions  24 ,  25 ,  26 . While described and depicted herein as having three portions  24 ,  25 ,  26 , chute  22  may, alternatively, be formed from a single portion, two portions, or, alternatively, may have a plurality of portions in excess of three. As shown in  FIG. 1 , chute  22  is in a folded condition, i.e., portions  25 ,  26  of chute  22  are in an upright position relative to portion  24  of chute  22 , to prevent chute  22 , and, specifically, portions  25 ,  26 , from projecting outwardly from the front of truck  10 . During the discharge of concrete from drum  18 , chute  22  is placed in an unfolded condition (not shown), in which portions  24 ,  25 ,  26  are aligned with one another, to provide a discharge path for concrete exiting discharge opening  20 . 
     As shown in  FIG. 1 , cab  28  is also positioned on chassis  16  of truck  10 . Cab  28  is occupied by an operator who controls the operation of truck  10  from within cab  28 . Specifically, referring to  FIGS. 2 and 3 , cab  28  includes dashboard  30  having a plurality of controls positioned thereon, steering wheel  32 , and foot pedals  34 . For example, positioned within cab  28  on dashboard  30  are controls that may be desirable to facilitate the operation of truck  10 , such as controls for an onboard water tank, a slump gage, and/or axle controls. Additionally, positioned within cab  28  is driver seat  36 , which supports the operator while driving truck  10  or otherwise operating the same to place concrete at a jobsite. 
     Referring to  FIGS. 1 and 3 , steering wheel  32  is connected to wheels  15  in a known manner, such that rotation of steering wheel  32  causes corresponding rotation of wheels  15 , and functions to allow the operator to steer truck  10  from within cab  28 . Additionally, foot pedals  34  may include a throttle or gas pedal and a brake pedal, both of which operate in a traditional manner to control the throttle of engine  12  and the braking of truck  10 , respectively. In order for the operator to control the direction of movement of truck  10 , primary shift selector  38  is provided within cab  28 . As shown in  FIGS. 3 and 4 , primary shift selector  38  may include a plurality of buttons  40  that may be depressed or otherwise actuated to place transmission  14  in one of the forward condition, the reverse condition, and the neutral condition and correspondingly cause transmission  14  to leave another of the forward condition, the reverse condition, and the neutral condition. 
     In one exemplary embodiment, primary shift selector  38  is also connected to a transmission control module  64  ( FIG. 5 ), as discussed below, to control the operation of transmission  14 . Primary shift selector  38  may be connected to transmission control module  64  in any manner, such as by an electronic connection. Alternatively, in another exemplary embodiment, primary shift selector  38  may be a lever or gear shift connected to transmission  14 , either directly or indirectly, to cause transmission  14  to enter one of the forward condition, the reverse condition, and the neutral condition and leave another of the forward condition, the reverse condition, and the neutral condition. In this manner, by actuating primary shift selector  38 , the operator may control operation of transmission  14  and, correspondingly, control the direction of movement of truck  10 . 
     Further, in order to facilitate the placement of concrete at a jobsite, joystick  42  is provided within cab  28 , as shown in  FIGS. 2 and 3 . Referring to  FIGS. 2 ,  3 , and  7 A- 7 D, in one exemplary embodiment, joystick  42  is a control stick having Part Number 30869 and is commercially available from Terex Advance of Fort Wayne, Ind., a division of Terex Corporation. Joystick  42  is movable on at least two substantially orthogonal joystick axes. In a well known manner, movement of joystick  42  about the at least two substantially orthogonal joystick axes, results in corresponding movement of chute  22 , as described in detail below. In one exemplary embodiment, joystick  42  comprises a lever, the entirety of which is movable along at least two substantially orthogonal joystick axes. Alternatively, in another exemplary embodiment, joystick  42  is secured at end  44  to form a pivot. Joystick  42  is then pivotable about end  44  on at least two substantially orthogonal joystick axes. As a result of the movement of joystick  42 , chute  22  is correspondingly moved along at least two substantially orthogonal chute axes. For examples, chute  22  may be actuatable in an up/down direction along a first chute axis and in a left/right direction along a second chute axis. 
     Additionally, positioned on joystick  42  is secondary shift selector  46 . In one exemplary embodiment, secondary shift selector  46  is a three-position momentary hall effect switch. Secondary shift selector  46  may be used as an alternative to primary shift selector  38  and allows the operator to place transmission  14  in one of the forward condition, the reverse condition, and the neutral condition and cause the transmission to leave another of the forward condition, the reverse condition, and the neutral condition in a substantially similar manner to primary shift selector  38 . Advantageously, by providing secondary shift selector  46  on joystick  42 , the operator of truck  10  is capable of changing the direction of movement of truck  10 , while correspondingly changing the position of chute  22 . As a result, the operator does not need to remove a hand from joystick  42  in order to actuate primary shift selector  38 . Thus, the operator of truck  10  may substantially contemporaneously access all of the controls necessary to place concrete discharging from drum  18  through discharge opening  20  and onto chute  22  at a jobsite. 
     In one exemplary embodiment, joystick  42  further includes drum condition selector  48  positioned thereon. In one exemplary embodiment, drum condition selector  48  is a three-position momentary hall effect switch. Drum condition selector  48  is actuable to cause drum  18  to enter one of the charge condition and the discharge condition from the other of the charge condition and the discharge condition. For example, if drum  18  is in the charge condition, drum control selector  48  may be actuated to cause drum  18  to exit the charge condition and enter the discharge condition. In another exemplary embodiment, joystick  42  further includes chute condition switch  50 , which causes chute  22  to fold and/or unfold as desired. Additionally, joystick  42  may include emergency stop switch  52 , which, when actuated, causes rotation of drum  18  to substantially immediately stop. This allows the operator to substantially immediately stop the discharge of concrete from drum  18  or otherwise stop rotation of drum  18  to prevent damage to truck  10  or adjacent equipment and/or to prevent injury to other personnel on the jobsite. Furthermore, in one exemplary embodiment, joystick  42  includes an additional safety mechanism in the form of trigger control  54 . Trigger control  54  is positioned on the underside of joystick  42  and must be depressed by the operator in order to engage joystick  42 . Thus, unless trigger control  54  is depressed, joystick  42  will not function. 
     Referring to  FIGS. 4-8B , the operation of joystick  42  and the corresponding control system is described in accordance with an exemplary embodiment. Specifically, referring to  FIG. 5 , the schematic of an embodiment of the control system including joystick  42  as shown. In this embodiment, joystick  42  is shown in electronic communication with an electronic control module  56 . Electronic control module  56  is a generic computer control module that is capable of receiving input from a variety of electronic sources, processing the input in accordance with preloaded instructions in the form of computer readable code, and, in accordance with the preloaded instructions, providing an output in the form of an electrical signal to other control components or devices. The programming of an electronic control module like electronic control module  56  is well within the knowledge of one skilled in that art of programming controllers of this type. In one exemplary embodiment, electronic control module  56  is a generic electronic control module having Part Number 24282 and is commercially available from Terex Advance of Fort Wayne, Ind., a division of Terex Corporation. In this embodiment, electronic control module  56  functions as a hub that receives electronic signals from and delivers electronic signals to each of the corresponding components of the control system, as described in detail below. While described with specific reference to electronic control module  56 , other exemplary control systems may be utilized in which electronic control module  56  is replaced or eliminated. For example, several different exemplary embodiments of control systems that operate without electronic control module  56  are described in detail herein. 
     Electronic control module  56  receives signals from joystick  42  regarding the position of joystick  42  and the actuation of any selectors or switches positioned thereon. For example, the position of joystick  42  may be monitored by a hall effect sensor which electronically transmits signals to electronic control module  56  that correspond to the position of joystick  42 . Based on the signals received by electronic control module  56  regarding the position of joystick  42 , electronic control module  56  transmits to chute controller  58  electronic signals requesting movement of chute  22  into a position that corresponds to the position of joystick  42 . For example, in one exemplary embodiment, chute controller  58  is an electric/hydraulic manifold assembly, such as assembly  60  shown in  FIGS. 8A and 8B . In one exemplary embodiment, electronic/hydraulic manifold assembly  60  is an electronic/hydraulic manifold assembly having Part Number 24327 and is commercially available from Terex Advance of Fort Wayne, Ind., a division of Terex Corporation. 
     Assembly  60  is electronically connected to electronic control module  56  and hydraulically connected to chute  22 . Thus, upon receipt of an electronic signal from electronic control module  56 , motors, servomechanisms, and/or solenoids, for example, such as those identified at  62  in  FIGS. 5 ,  8 A, and  8 B, may be actuated to control the flow of hydraulic fluid through manifold assembly  60 . The resulting flow of hydraulic fluid causes movement of chute  22  that corresponds to the electrical signal received. Thus, based on the electronic signal received by manifold assembly  60  from electronic control module  56 , chute  22  may be correspondingly moved along the at least two substantially orthogonal chute axes. In one exemplary embodiment, joystick  42  may be limited to movement along two substantially orthogonal joystick axes, so that chute  22  would be correspondingly limited to movement in one of an up/down and a left/right direction at any given time. In contrast, joystick  42  may be freely moveable about a plurality of joystick axes, such that chute  22  would be correspondingly moveable in a combination of the up/down and left/right directions at the same time. In another exemplary embodiment, movement of joystick  42  may result in proportional movement of chute  22 . For example, if joystick  42  is moved one centimeter in a leftwardly direction, chute  22  may begin moving to the left at one inch per second. However, if joystick  42  is moved two centimeters in a leftwardly direction, chute  22  may begin moving to the left at four inches per second. Thus, in this embodiment, each incremental increase the movement of joystick  42  results in a substantially exponential increase in the movement of chute  22 . 
     For example, referring to  FIG. 13 , upon receipt of an electronic signal from electronic control module  56 , manifold assembly  60  may actuate motors, servomechanisms, and/or solenoids  62  to control to flow of hydraulic fluid to and from hydraulic cylinders  80 ,  82 , which control the rotational movement of chute  22 . Specifically, as shown in  FIGS. 1 and 13 , cylinders  80 ,  82  include pistons  84 ,  86 , respectively, that are connected to opposing ends of chain  88 . Chain  88  extends around sprocket  90  and engages teeth  92  on sprocket  90 , such that movement of chain  88  results in corresponding rotation of sprocket  90 . As shown in  FIG. 1 , chute  22  is secured to sprocket  90 , such that rotation of sprocket  90  results in corresponding rotation of chute  22 . 
     As indicated above, in order to rotate chute  22  in a first direction, electronic control module  56  may send an electric signal to manifold assembly  60  indicating that chute  22  should be rotated in a first direction. Upon receipt of the electronic signal, manifold assembly  60  actuates motors, servomechanisms, and/or solenoids  62  to cause hydraulic fluid to enter cylinder  82  through inlet  85  on a first side of piston  86  to cause piston  86  to retract into cylinder  82  and hydraulic fluid in cylinder  82  opposite piston  86  to exit cylinder  82  through outlet  87 . As piston  86  retracts, piston  84  extends out of cylinder  80  causing hydraulic fluid to exit cylinder  80  through inlet  81  and enter cylinder  80  through outlet  87 . Due to the retraction of piston  86  into cylinder  82 , chain  88  is pulled in the direction of cylinder  82 , which causes sprocket  90  to rotate in the direction of arrow C of  FIG. 13 . 
     Similarly, in order to rotate chute  22  in an opposite, second direction, electronic control module  56  may send an electric signal to manifold assembly  60  indicating that chute  22  should be rotated in the opposite, second direction. Upon receipt of the electronic signal, manifold assembly  60  actuates motors, servomechanisms, and/or solenoids  62  to cause hydraulic fluid to enter cylinder  80  through inlet  81  on a first side of piston  84  to cause piston  84  to retract into cylinder  80  and cause hydraulic fluid in cylinder  80  opposite piston  84  to exit cylinder  80  through outlet  87 . As piston  84  retracts, piston  86  extends out of cylinder  82  causing hydraulic fluid to exit cylinder  82  through inlet  85  and enter cylinder  82  through outlet  87 . Due to the retraction of piston  84  into cylinder  80 , chain  88  is pulled in the direction of cylinder  80 , which causes sprocket  90  to rotate in the direction of arrow D of  FIG. 13 . 
     In another exemplary embodiment, chute  22  is actuated by a gearbox (not shown) connected to a hydraulic motor. In this embodiment, opposing ends of chain  88  are connected to one another so that chain  88  forms a continuous loop. Chain  88  is engaged with teeth on sprocket  90 , shown in  FIG. 13 , and with teeth on a sprocket driven by the gearbox. Thus, when manifold assembly  60  receives an electronic signal from electronic control modular  56 , manifold assembly  60  supplies hydraulic fluid to the hydraulic motor that drives the gearbox. Rotation of the sprocket of the gearbox results in rotation of chain  88  and, correspondingly, sprocket  90  and chute  22 . 
     In order to adjust the elevation of chute  22 , electronic control module  56  may send an electric signal to manifold assembly  60  indicating that chute  22  should be raised or lowered. As shown, hydraulic cylinder  94  is pivotably and rotatably secured to frame  16  of truck  10  at a first end and is pivotably secured to chute  22  at a second end. Specifically, cylinder  94  is secured to frame  16  at pivot point  98  and piston  96  of cylinder  94  is secured to first section  24  of chute  22  at pivot point  100 . Upon receipt of an electronic signal indicating that chute  22  should be raised and/or lowered, manifold assembly  60  actuates motors, servomechanisms, and/or solenoids  62  to cause hydraulic fluid to enter and/or exit hydraulic cylinder  94 , shown in  FIG. 1 . 
     For example, when chute  22  is to be raised, hydraulic fluid is directed into an inlet in cylinder  94  on a first side of piston  96  and exits cylinder  94  through an outlet in cylinder  94  on an opposing, second side of piston  96  to cause piston  96  to extend from cylinder  94  in a known manner. As a result, cylinder  94  and piston  96  pivot about points  98 ,  100  and increase the elevation or raise first section  24  of chute  22  and sections  25 ,  26  of chute  22  that are supported by first section  24  as described above. Alternatively, when chute  22  is to be lowered, hydraulic fluid is directed into the outlet of cylinder  94  and exits cylinder  94  through the inlet in cylinder  94  to cause piston  96  to retract into cylinder  94  in a known manner. As a result, cylinder  94  and piston  96  pivot about point  98 ,  100  and decrease the elevation or lower first section  24  of chute  22  and sections  25 ,  26  of chute  22  that are supported by first section  24  as described above. 
     Additionally, while described and depicted herein with specific reference to a hydraulic connection, manifold assembly  60  may be connected to chute  22  by an electronic connection, a pneumatic connection, or a mechanical connection, for example. Furthermore, if joystick  42  includes chute condition switch  50  positioned thereon, joystick  42  may also be used to control the folding and/or unfolding of chute  22 . For example, chute condition switch  50  may be connected to electronic control module  56 . In this embodiment, the actuation of chute condition switch  50  will cause a corresponding electronic signal to be sent to electronic control module  56 . Electronic control module  56  then processes the signal and relays a corresponding signal to manifold assembly  60  to actuate motors, servomechanisms, and/or solenoids  62 . The actuation of motors, servomechanisms, and/or solenoids  62  causes a corresponding flow of hydraulic fluid to hydraulic cylinders connected to sections  24 ,  25 ,  26  of chute  22  that results in the actuation of chute  22  between one of a folded position and an unfolded position. 
     In addition, secondary shift selector  46 , which is positioned on joystick  42 , is also connected to electronic control module  56 , which, in addition to primary shift selector  38  discussed above, is electronically connected to transmission control module  64 , as shown in  FIG. 4 . Transmission control module  64  is operable connected to transmission  14  and controls the operation of transmission  14 . For example, transmission control module  64  may include a central processing unit or CPU, which is loaded with computer readable code that controls the operation and shifting of transmission  14 . In one exemplary embodiment, transmission control module  64  is an Allison transmission control module having part number A410098J, commercially available from Allison Transmission, Inc., of Indianapolis, Ind. 
     By connecting both primary shift selector  38  and secondary shift selector  46  via control module  56  to transmission control module  64 , transmission control module  64  may receive commands from either primary shift selector  38  or secondary shift selector  46  and, thus, either primary shift selector  38  or secondary shift selector  46  may be used to control transmission  14 . In order to alternate the control of transmission  14  between primary shift selector  38  and secondary shift selector  46 , transmission shift select switch  66  is actuated. Thus, with transmission shift select switch  66  actuated to allow secondary shift selector  46  to control transmission  14 , secondary shift selector  46  may be actuated to send an electronic signal to electronic control module  56  which, correspondingly, sends a signal to transmission control module  64 . Based on the signal sent by secondary shift selector  46  to electronic control module  56 , the signal sent by electronic control module  56  to transmission control module  64  results in transmission control module  64  causing transmission  14  to enter one of the forward condition, the reverse condition, and the neutral condition and leave another of the forward condition, the reverse condition, and the neutral condition. For example, if secondary shift selector  46  is actuated to place secondary shift selector  46  in a forward condition from a neutral condition, electronic control module  56  will receive an electronic signal from secondary shift selector  46  and transmit a corresponding signal to transmission control module  64 , which will actuate transmission  14  to cause transmission  14  to leave the neutral condition and enter the forward condition. 
     Additionally, in one exemplary embodiment, in order to operate transmission  14  via secondary shift selector  46 , pressure switch  68 , shown in FIGS.  4  and  9 - 12 , must also be activated. Pressure switch  68  is connected to transmission  14  and functions as a redundant safety mechanism. Specifically, pressure switch  68  is activated when the pressure of fluid in the transmission system lines is sufficient to indicate that the transmission has been placed into low gear. By utilizing pressure switch  68 , an operator of truck  10  is prevented from controlling transmission  14  via secondary shift selector  46  during on-road operation of truck  10  at speeds in excess of those available in low gear. Thus, once the transmission is placed into low gear and transmission shift select switch  66  actuated, secondary shift selector  46  may be used to control transmission  14 . 
     As shown in  FIG. 4 , drum condition selector  48 , which is positioned on joystick  42 , may also be connected to electronic control module  56 . In this embodiment, actuation of drum condition selector  48  on joystick  42  results in the transmission of an electric signal from drum condition selector  48  to electronic control module  56 . Electronic control module  56  then processes the signal and relays a corresponding signal to drum control  70 , which is electronically connected thereto and which controls the rotation of drum  18 . Specifically, in response to the signal received from electronic control module  56 , drum control  70  causes actuation of drum  18  from one of the charge condition and the discharge condition to the other of the charge condition and the discharge condition. For example, if drum condition selector  46  is actuated to the discharge condition, a corresponding signal is sent to electronic control module  56 , which sends a signal to drum control  70 . Drum control  70  then actuates drum  18  from the charge condition to the discharge condition. In exemplary embodiments, drum control  70  may be an electronic/hydraulic manifold assembly, such as an electronic hydraulic manifold assembly similar to electronic hydraulic manifold assembly  60 , or, alternatively, may be mechanically, pneumatically, electronically, or hydraulically connected directly to drum  18  or a corresponding control system therefore. 
     For example, referring to  FIG. 15 , an exemplary embodiment of drum control  70  is shown as drum control system  100  and includes electronic controller  101 , which receives electronic signals from electronic control module  56 . Upon receipt of electronic signals from electronic control module  56 , electronic controller  101  is connected to hydrostatic pump  102  through electronic connection  103  and is configured to actuate motors, servomechanisms, and/or solenoids, such as proportional solenoids, to mechanically actuate a swash plate of hydrostatic pump  102 . Hydrostatic pump  102  may be powered by engine  12  of truck  10  ( FIG. 1 ), or may be powered in any other manner known in the art. Hydrostatic pump  102  is part of fluid circuit that includes hydraulic fluid tank  104 , valve  106 , and hydraulic motor  116 . 
     Pump  102  is in fluid communication with tank  104  through hydraulic lines  108 ,  110 . Tank  104  includes a reserve of hydraulic fluid which may be accessed by pump  102  and circulated through the fluid circuit. For example, when electronic controller  101  receives a command to place drum  18  ( FIG. 1 ) in the charge condition, electronic controller  101  causes actuation of the swash plate of pump  102  in a first, charge direction. By actuating swash plate  102  in a first, charge direction, pump  102  will begin pumping hydraulic fluid through the fluid circuit. Specifically, with valve  106  closed, fluid pumped by pump  102  cannot travel through lines  108 ,  110  and return to pump  102 . As a result, the hydraulic fluid is directed through hydraulic line  112 , motor  116 , and hydraulic line  114 . Motor  116  is mechanically connected to gear box  118  and, as hydraulic fluid travels through motor  116 , an output shaft of motor  116  rotates. The output shaft of motor  116  is connected to gearbox  118 , which is, in turn, mechanically connected to drum  18 . Thus, as the output shaft of motor  116  is rotated it transfers power to gearbox  118  and gearbox  118  causes drum  18  to rotate in a first direction that places drum  18  in the charge condition. In order to drive rotation of drum  18 , gear box  118  may include a gear having teeth that mesh with corresponding teeth on a gear extending around the exterior of drum  18 . Thus, as the gear of gearbox  118  rotates, it causes corresponding rotation of drum  18 . 
     In one exemplary embodiment, when electronic controller  101  receives a command to place drum  18  in the discharge condition, the swash plate of pump  102  is actuated in a second, discharge direction, such that pump  102  pumps hydraulic fluid through hydraulic line  114 , motor  116 , and hydraulic line  112 , respectively. By reversing the flow of hydraulic fluid through motor  116 , the output shaft of motor  116  is rotated in the opposite direction. As a result, gearbox  118  and, correspondingly, drum  18  are also rotated in a reverse direction, placing drum  18  in the discharge condition. 
     Additionally, as indicated above, in the event that an emergency drum stop signal is received by electronic control module  56 , electronic control module  56  relays an electronic signal to control system  101  of drum control  100 . Control system  101  then actuates the swash pate of pump  102  to place pump  102  in a neutral condition, while immediately opening solenoid valve  106  via electronic connection  117 , allowing any hydraulic fluid still being pumped by pump  102  to pass through hydraulic lines  108 , tank  104 , and hydraulic line  110 , causing all movement of motor  116 , gear box  118 , and/or drum  18  to cease. In this manner, the fluid circuit including pump  102  and motor  116  is effectively short circuited to cause movement of drum  18  to stop. 
     Referring to  FIG. 9 , another exemplary embodiment of a control system utilizing joystick  42  is shown. In this embodiment, joystick  42 , and specifically, secondary shift selector  46 , is directly connected to transmission control module  64 . In one exemplary embodiment, the connection between secondary shift selector  46  and transmission control module  64  is an electronic connection. Additionally, in a similar manner as described above with specific reference to  FIG. 4 , primary shift selector  38 , transmission shift select switch  66  and pressure switch  68  are also connected to transmission control module  64 . Thus, as described in detail above with reference to  FIG. 4 , when transmission shift select switch  66  and pressure switch  68  are activated, actuation of secondary shift selector  46  results in a signal being transmitted to transmission control module  64 , which controls transmission  14  and results in transmission  14  entering one of the forward condition, the reverse condition, and the neutral condition and leaving another of the forward condition, the reverse condition, and the neutral condition. In other exemplary embodiments, secondary shift selector  46  may be connected to transmission control module  64  by one of a mechanical, hydraulic, or pneumatic connection, for example. 
     Additionally, as shown in  FIG. 9 , joystick  42  is connected to chute controller  58 . For example, joystick  42  may be directly connected to chute controller  56  by cables  72 , for example. In this manner, actuation of joystick  42  results in corresponding actuation of cable  72 , which, in turn, causes chute controller  58  to correspondingly actuate chute  22 , as described in detail above. Further, joystick  42 , and, specifically, drum condition selector  68  is also connected to drum control  70 . In one exemplary embodiment, drum condition selector  68  is electronically connected to drum control  70 . Thus, when drum condition selector  68  is actuated, a signal is sent from drum condition selector  68  to drum control  70 . Responsive to the signal sent from drum condition selector  68 , drum control  70  correspondingly causes actuation of drum  18  from one of the charge condition and the discharge condition to the other of the charge condition and the discharge condition. In other exemplary embodiment, drum condition selector  68  may be connected to drum control  70  by one of a mechanical, hydraulic, or pneumatic connection, for example. 
     Referring to  FIG. 10 , another exemplary embodiment of a control system including joystick  42  is shown. In this embodiment, secondary shift selector  46  and drum condition selector  68  may be connected to transmission control module  64  and drum control  70 , respectively, in a substantially similar manner as described above with reference to  FIG. 9 . Additionally, in this embodiment, joystick  42  is directly connected to chute controller  58 . In this embodiment, joystick  42  is connected to chute controller  58  by a mechanical linkage. Thus, by actuation of joystick  42 , mechanical linkage  74  is correspondingly actuated in a known manner. For example, linkage  74  may be connected to motors, servomechanisms, and/or solenoids  62  of chute controller  52 . The actuation of linkage  74  activates motors, servomechanisms, and/or solenoids  62  in a manner that results in chute  22  moving into a position that corresponds to the position of joystick  42 . For example, linkage  74  may be formed in a manner such as disclosed in U.S. Pat. No. 5,816,105 to Adelstein, entitled “THREE DEGREE OF FREEDOM PARALLEL MECHANICAL LINKAGE,” issued Oct. 6, 1998, and/or U.S. Pat. No. 5,316,435 to Mozingo, entitled “THREE FUNCTION CONTROL SYSTEM,” issued May 31, 1994, the entire disclosures of which are expressly incorporated by reference herein. 
     Referring to  FIG. 11 , another exemplary embodiment of a control system including joystick  42  is shown. In this embodiment, secondary shift selector  46  is connected to transmission control module  64  in a substantially similar manner as that shown and described with reference to  FIG. 9 . Additionally, in this embodiment, joystick  42  is directly connected to chute controller  58 . In this embodiment, joystick  42  is connected to chute controller  58  by hydraulic connection  76 . Thus, by actuation of joystick  42 , a hydraulic pump and/or manifold is actuated and results in hydraulic fluid traveling through hydraulic connection  76  to chute controller  58 . For example, joystick  42  may be connected to the swash plate of a hydraulic pump to cause hydraulic fluid to travel through hydraulic connection  76  to chute controller  58 . In this embodiment, chute controller  58  may act to direct the hydraulic fluid as necessary to result in corresponding movement of chute  22 . Thus, the actuation of joystick  42  results in hydraulic fluid traveling through hydraulic connection  76  to a chute controller  58 , which actuates chute  22  to move chute  22  to a position that corresponds to the position of joystick  42 . 
     Referring to  FIG. 12 , another exemplary embodiment of a control system including joystick  42  is shown. In this embodiment, secondary shift selector  46  is connected to transmission control module  64  in a substantially similar manner as that shown and described with reference to  FIG. 9 . Additionally, in this embodiment, joystick  42  is directly connected to chute controller  58 . In this embodiment, joystick  42  is connected to chute controller  58  by pneumatic connection  78 . Thus, by actuation of joystick  42 , a pneumatic pump and/or manifold is actuated that results in pressurized air traveling through pneumatic connection  78  to chute controller  58 , which actuates chute  22  to move chute  22  to a position that corresponds to the position of joystick  42 . 
     For example, actuation of joystick  42  may result in air traveling through pneumatic connection  78  and, as shown in  FIG. 14 , into air chamber  120  of pneumatic control  121 . Specifically, referring to  FIG. 14 , air chamber  120  is separated into sections  122 ,  124  by plunger  126 , which engages upper and lower walls  128 ,  130  defining chamber  120  to form a fluid tight seal therebetween. Plunger  126  is biased into a neutral position at the center of chamber  120  by spring  132 . When air travels through pneumatic connection  78  and enters section  122  of chamber  120  through air hose  136 , the biasing force of spring  132  may be overcome by plunger  126  and plunger  126  may be advanced in the direction of arrow F of  FIG. 1 . Alternatively, air may be received within section  124  of chamber  120  by allowing air to enter through air hose  134 , causing movement of plunger  126  in the direction of arrow E of  FIG. 14 . By adjusting the position of plunger  126 , a mechanical linkage, formed generally at  136 , may be actuated to correspondingly actuate controls for motors, servomechanisms, and/or solenoids in a known manner that may control the movement of chute  22 , as described in detail above. 
     While this invention has been described as having a preferred design, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.