Abstract:
Hydraulic actuators and/or other parameters on a work attachment for a skid steer loader are controlled with a wireless remote control kit. The kit includes a manual input device and transmitter mounted to the skid steer loader and a receiver on the work attachment that communicates with the transmitter. The receiver directly couples the manual input from the vehicle operator to the solenoid valves that control hydraulic flow to the hydraulic actuators on the work attachment, without processing by an electronic controller. The response of hydraulic actuators directly corresponds to the manual input provided by the vehicle&#39;s operator. The manual input device, transmitter module and the independent power source may be self-contained in a module that is attachable and detachable to skid steer loader. The module can be removed and transferred along with the attachment such that the attachment is usable with different skid steer loaders.

Description:
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS  
       [0001]    This patent application claims the benefit of U.S. provisional patent application 60/299,202, filed Jun. 19, 2001, the entire disclosure of which is hereby incorporated by reference in its entirety. 
     
    
     
       FIELD OF THE INVENTION  
         [0002]    The present invention relates generally to commercial work vehicles such as skid steer loaders and attachments therefore, and more particularly relates to the operation and/or hydraulic control of attachments attached to commercial work vehicles such as skid steer loaders.  
         BACKGROUND OF THE INVENTION  
         [0003]    Skid steers, loader tractors and other commercial work vehicles are commonly used for many industrial, agricultural, and landscaping operations. These work vehicles typically have two laterally spaced loader arms that extend in front of the vehicle that are adapted to attach to a wide variety of attachments. A number of attachments can be selectively attached and detached from the loader arms or the three point hitch to make these work vehicles applicable to a wide variety of applications. For example, a bucket is commonly provided to dig, dump, and transport loose materials such as dirt, sand, and gravel. The loader arms are hydraulically driven to raise and lower the attachment and pivot the attachment in a horizontal axis.  
           [0004]    Skid steer loaders and other work vehicles commonly have a single hydraulic hook-up, which is typically comprised of a pair of quick connect hydraulic couplings (one for pressurized hydraulic flow and the other for low pressure return flow) that can be utilized by the attachment for any desired purpose. A control valve is provided in the operator cab for controlling the hydraulic flow to the attachment through the hydraulic couplings. The control valve may be a manually operated rocker lever valve which is common in older skid steer loaders (or less complex or less expensive current models) or an electronically operated control valve that is activated with an electronic trigger integrated into the control levers used to mobilize the vehicle in certain complex or modem skid steer loaders.  
           [0005]    One common use of the hydraulic output includes positioning the attachment tool (e.g. shifting the tool left or right about a vertical axis to effect a windrow and/or to direct dirt, gravel or debris, or raising and lowering or tilting the tool). The hydraulic output may also be used for hydraulically driving an engaging device such as the rotary rake of a rock raking attachment, a rotary blower of a snowblower, a rotary planner of a cold planner, or other rotary tool. More complex attachments include two or more hydraulic functions or actuators. For example, rotary broom attachments, snow-blower attachments, backhoes, cold planners are some of the attachments that often have two or more hydraulic functions or actuators.  
           [0006]    Although a single hydraulic hook up from the skid steer loader is sufficient for many applications, it is often insufficient for certain attachments where it is required, or desirable, to have hydraulic control over more than one function, such as rotary broom attachments. For example, rotary broom attachments often include: (1) a hydraulic cylinder for tilting the broom left or right about a vertical axis to direct swept debris or effect a windrow and (2) a hydraulically driven motor that rotates the broom to sweep material. Each of these two functions, however, must be supplied with hydraulic power from the single hydraulic hook up.  
           [0007]    The common approach for controlling two separate hydraulic functions with a single power source has been to use an electronically operated solenoid on the attachment downstream of the single hydraulic hook up. These solenoid valves switch the hydraulic power between the two functions. As is expressly recognized in U.S. Pat. No. 6,354,081, this can have significant drawbacks. One drawback is that electrical wiring harnesses, electrical hook-ups and electrical couplings from the skid steer loader are necessary to power and control solenoid valves. These electrical components increase the time and difficulty of attaching and detaching attachments. Loose wires can also break or sever when not properly secured or when not properly located out of the way when not in use. Due to the environment in which work attachments operate, these electrical components are also often subject to wear, poor and increased resistance connections, bent connector pins, short circuits and the like. In view of the foregoing, electrical hook-ups, wiring and couplings have lead to much aggravation for work vehicle operators, require frequent replacement, and are not desirable.  
           [0008]    A further complexity existing in the art is that loader vehicles are made by several different manufacturers that may or may not have integrated control systems wired into the electronics of the loader vehicle. Integrated control systems among different manufacturers may also have different protocols or operational standards/configurations. As noted above, some modern and complex machines have integrated triggers in the control levers that have traditionally operated the wheels of the loader vehicle. Older or less complex loader vehicles or less expensive modem loader vehicles are more simplistic and do not have integrated controls, but bare handle levers in the cab of the loader vehicle. Further, conforming the attachment control design to the available controls from a skid steer loader has severely limited the design of such attachments. That is, while the attachment manufacturer could implement advanced control features, the limitation of the type of control interface provided by the loader vehicle has prevented many of these advanced features from being released. Some attachments may be designed to be compatible with only one or a limited number of loader vehicles because of such interface constraints.  
           [0009]    In view of the foregoing, it is difficult to make an attachment that can be universally used with the different loader machines that exist in the commercial market. This has provided a barrier to technological innovations in the marketplace. If a work attachment were to have a specially configured control system that is set up for electrical communication with one commercial make and brand of a skid steer loader machine, the attachment would be incompatible or difficult to use with other types of skid steer machines, such as those providing insufficient controls to operate the work attachment. This has several disadvantages. For example, specialized work attachment control systems can make it difficult for distributors and retail companies to stock attachments for customers who own different makes, models and brands of skid steer loaders. This also makes it difficult for work attachment rental companies to stock work attachments for different customers who may have different brands, makes and models of skid steer loader machines. Lastly, this can also reduce the resale value of the work attachment for a customer as it may make the work attachment more unique and therefore more difficult to find a buyer, thus providing a disincentive for purchasing the work attachment in the first place.  
         BRIEF SUMMARY OF THE INVENTION  
         [0010]    In light of the above, it is a general aim of the present invention to eliminate the need for electrical wiring hook ups, electrical couplings, and electrical wiring on attachments for work vehicles that have more than one operational parameter or hydraulic function.  
           [0011]    In that regard, it is a further objective of the present invention to provide a work attachment that is substantially universal and can be used among different brands, makes and models of machinery without concern about whether sufficient controls on the skid steer loader exist for operating the work attachment.  
           [0012]    In accordance with these and other objectives, the present invention is directed towards a wireless remotely controlled work attachment for a skid steer loader vehicle or other similar commercial loader vehicle. Wireless communication is achieved through a manual input device and transmitter, which may be mounted on the loader vehicle and a receiver on the work attachment that receives wireless transmissions from the transmitter.  
           [0013]    According to one aspect of the present invention, the manual input device and transmitter module is independently powered and not connected to the electrical system of the skid steer vehicle. In this regard, it is a further aspect that the manual input device, transmitter module and the independent power source may be self-contained in a housing that is attachable and detachable to skid steer loader. The module can thus be removed and transferred along with the attachment such that the work attachment is universal and can be used with different makes and models of skid steer loaders, regardless of the available features and control interface provided by the skid steer loader.  
           [0014]    According to different aspect of the present invention, the wireless receiver directly couples the manual input of the vehicle&#39;s operator to the solenoid valves or other electrical switches that control hydraulic flow or other parameters on the work attachment, without any processing by an electronic controller. This provides for hydraulic actuator/parameter response that directly corresponds to the manual input provided by the vehicle&#39;s operator.  
           [0015]    It is a feature that the present invention may be incorporated into a kit and used to replace worn out wires on existing attachments, or incorporated into a new work attachment as an alternative to control wire harnesses. The provision of a kit provides for easy and inexpensive incorporation of the present invention into a work attachment. To further enhance the universal applicability of the kit, the wireless receiver includes a feature that allows the output control channels to be selectable between latching and momentary control outputs.  
           [0016]    It is another feature of the present invention that the work attachment may include a battery and battery recharger to provide an independent and rechargeable power supply on the work attachment.  
           [0017]    It is another feature of the present invention that the manual input and transmitter device may removably mount directly to the control levers in the cab of a skid steer loader vehicle that operate the wheels of the vehicle. According to one embodiment, a dial is provided to switch between channels that operate different hydraulic actuators or other parameters on the work attachment, and a trigger to generate control signals along the dialed channel. The dial may be operated with one finger such as a thumb, while the trigger may be operated with a different finger such as an index finger. This allows a vehicle operator to control parameters on the skid steer while at the same time controlling different parameters on the work attachment.  
           [0018]    Other objectives and advantages of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0019]    The accompanying drawings incorporated in and forming a part of the specification illustrate several aspects of the present invention, and together with the description serve to explain the principles of the invention. In the drawings:  
         [0020]    [0020]FIG. 1 is a schematic view of work apparatus having a wireless remote control kit installed on a rotary broom attachment and a skid steer loader vehicle according to a first embodiment of the present invention.  
         [0021]    [0021]FIG. 2. is an isometric view of a work attachment having the wireless remote control kit installed thereon and a mountable transmitter module for use therewith as schematically indicated in FIG. 1.  
         [0022]    [0022]FIG. 3 is a side elevation view of the work vehicle apparatus shown in FIG. 2.  
         [0023]    [0023]FIG. 4 is a schematic electrical diagram of the switching circuit of the wireless remote control kit shown in FIG. 1.  
         [0024]    [0024]FIG. 5 is a schematic view of work apparatus comprising a cold planer attachment and a skid steer loader vehicle according to a second embodiment of the present invention.  
         [0025]    [0025]FIG. 6 is a perspective illustration of one embodiment of a wireless remote control kit for use on a loader vehicle and work attachment.  
         [0026]    [0026]FIG. 7 is a perspective illustration of another embodiment of the transmitter of a wireless remote control kit for use on a loader vehicle and work attachment.  
         [0027]    While the invention will be described in connection with certain preferred embodiments, there is no intent to limit it to those embodiments. On the contrary, the intent is to cover all alternatives, modifications and equivalents as included within the spirit and scope of the invention as defined by the appended claims. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0028]    Referring to the drawings and specifically to FIGS.  1 - 3 , it can be seen that the present invention generally relates to the field of commercial work vehicles such as a skid steer loader  10  as shown, or other loader tractors, tractors and similar commercial work vehicles. A skid steer loader  10  is adapted for use in many industrial, agricultural and landscaping applications wherein easy maneuverability, power lifting and transporting capabilities are desired. The skid steer loader  10  is provided with a pair of laterally spaced loader arms  12  that are driven along an arcuate path by hydraulic cylinders  14 . The loader arms  12  are pivotally mounted to the main body of the skid steer loader  10  on each side of the operator cab  16 . The skid steer loader  10  is mobilized forwardly and rearwardly through two control levers  17 , one on each side of the operator&#39;s seat. The control levers  17  control the hydraulic flow that operate the wheels  15  on opposite sides of the skid steer loader  10 . When each control lever  17  is manually pushed forward, its corresponding wheel  15  turns to move the loader vehicle forward. When control lever  17  is manually pushed rearward, its corresponding wheel  15  turns in a reverse direction to move the loader vehicle rearward. Through operation of the control levers  17 , the vehicle can be selectively manipulated to move forward, rearward, turn, and spin about as may be desired.  
         [0029]    Toward the front end of the loader arms  12  there is provided a mounting structure which takes the form in this embodiment as a quick attach plate  18  as is well known in the art. The quick attach plate  18  allows for selective attachment and detachment of the skid steer loader  10  to a wide variety of attachments for industrial, agricultural, construction, landscaping, commercial and other applications.  
         [0030]    For purposes of illustration to demonstrate one of the many different applications of the present invention, the attachment is shown in the form of a rotary broom attachment  20  as shown in FIGS.  1 - 3 . However, it will be understood that the invention is applicable to any one of a variety of attachments such as but not limited to a backhoe, a rotary broom, a snow blower, a tree spade, grapples, or other such similar implements. One common element of each of the attachments to which the present invention pertains is that these attachments have multiple controlled parameters such as fluid powered actuators (typically either hydraulic cylinders or hydraulic rotary motors, although the invention may also be applicable to local pneumatic power systems and electrical motors/devices as well).  
         [0031]    The rotary broom attachment  20  includes a mounting support structure  21  (including a quick attach plate  22 ), a broom support frame  24 , and a rotary broom  26 . The quick attach plate  22  is adapted to be quickly attached and detached from the quick attach plate  18  of the skid steer loader  10  in a well-known conventional manner. The rotary broom  26  is mounted for rotation to the broom support frame  24  in a conventional manner. A first hydraulic actuator, namely a hydraulic rotary motor  28 , is mounted to an end of the broom support frame  24  and drives the rotary broom  26  about its axis of rotation to provide for sweeping of dirt, debris, gravel and other material. The broom support frame  24  is pivotably mounted about a vertical axis to the mounting support structure that supports the quick attach plate  22  such that the rotary broom  26  may be pivoted left or right to direct dirt, debris, gravel and other material being swept by the rotary broom  26 . To control the tilt position of the broom  26 , a second hydraulic actuator shown in the form of a hydraulic cylinder  30  is mounted between the support structure  21  and the broom support frame  24  such that expansion and contraction of the hydraulic cylinder  30  pivots the broom to the desired angle. A pair of stabilizer spring supports  32  is also connected between the support structure  21  and the broom support frame  24 .  
         [0032]    Referring to FIGS. 1 and 2, the disclosed embodiment includes two different hydraulic functions, including a tilt function and a broom rotation function. With this being said, only one hydraulic working output is typically available from the hydraulic system  33  of the skid steer loader  10 , through a pair of quick-connect hydraulic couplings  34  from the hydraulic system  33 . During operation, one of the hydraulic couplings  34  carries high pressure hydraulic fluid from the skid steer&#39;s hydraulic pump  36  while the other hydraulic coupling vents the return flow of low pressure hydraulic fluid to the skid steer&#39;s hydraulic sump  38 . The hydraulic couplings  34  attach to hydraulic hoses or lines  35 ,  37  of the work attachment  20 . A manual control (which may be electronically triggered or a manually operated lever) is provided in the operator cab  16  (FIG. 3) to provide control over a four-way, three position, blocked center, control valve  40  (although in some cases, this may be an on/off valve). In the disclosed embodiment, the skid steer&#39;s control valve  40  has three possible positions shown schematically in FIG. 1 including a first position shown in which hydraulic flow is directed in one direction through hydraulic lines  35 ,  37 , a second position in which hydraulic flow is reversed in the hydraulic lines  35 ,  37 , and a third position that prevents hydraulic flow to the rotary broom attachment  20  altogether.  
         [0033]    A solenoid valve  42  is provided to control hydraulic flow to the hydraulic cylinder  30 . In this embodiment, the solenoid valve  42  is shown as a three position valve  46  with two springs  48  and two solenoids  50 . The springs  48  are arranged to bias the valve  46  to the center position as shown schematically in FIG. 1. As shown the solenoid valve  42  may be centralized in a single hydraulic control block  51  along with other valves/plumbing and input/output ports to receive, distribute, and return hydraulic power transmitted and returned through hydraulic input hoses or lines  35 ,  37 .  
         [0034]    For the hydraulic motor  28 , a hydraulically responsive valve  44  is normally open when hydraulic power is provided. The hydraulic motor  28  can be shut off via the operator control valve  40  that is provided in the skid steer loader  10 . Alternatively, an on/off solenoid valve (having a single spring and solenoid) may be connected in series with the hydraulic motor  28  to selectively turn on and off the broom attachment electronically utilizing a channel. For the hydraulic cylinder  30 , the solenoid valve  42  is centered to hold the angular position of the broom  20 . As such, the spring  48  biases the solenoid valve  42  to the center position. The hydraulic cylinder  30  can be driven in either direction by selectively actuating the solenoids  50 .  
         [0035]    By using the springs  48  to bias the solenoid valve  42  center operating position (e.g. the normal operating position), electrical power necessary to control the work attachment  20  through the solenoids  50  is minimized. This is important because the power used to activate the solenoids  50  is provided by a local power source on the work attachment  20  thereby avoiding electrical power wires between the work attachment  20  and the skid steer loader  10  in a preferred embodiment. As shown schematically in FIG. 1, two electrical lines  54 ,  56  are provided to provide separate control over the two solenoids  50  of the solenoid valve  42 . Each electrical line  54 ,  56  may be connected to a different solenoid valve (e.g. to different on-off valves), to different solenoids  50  for the same valve  42  as is shown in FIG. 1, or alternatively to multiple solenoid valves to allow for activation of different hydraulic functions or other work attachment parameters simultaneously. In any event, each electrical line  54 ,  56  represents a different operational channel for controlling hydraulic functions or other parameters independently. The electrical lines or channels may also be used with non-hydraulic functions. For example, a third electrical line  55  is illustrated for operating an electrical spotlight  27 . Although multiple channels or electrical lines  54 ,  55 ,  56  or channels are shown in the embodiment of FIGS.  1 - 3 , it will be appreciated that more or less electrical lines or channels may be used to provide for the desired control over the number of different hydraulic functions or other parameters that are provided on a work attachment.  
         [0036]    In accordance with the present invention, the work apparatus of the first embodiment includes a wireless remote control kit  62  installed thereon. Referring to FIGS.  1 - 3 , and  6  the kit  62  includes a transmitter module  64  mounted to or otherwise provided in the skid steer loader  10 , a receiver module  66  mounted to the work attachment  20  and the dedicated electrical wires or lines  54 ,  55 ,  56  for connecting the receiver module to differently controlled parameters on the work attachment. The transmitter module  64  may be independent or separate of the electrical power and control system  65  of the skid steer loader  10 . The transmitter module  64  includes an operator input device  68 , a local power supply shown in the form of a battery  70 , an encoder/transmitter  72 , a housing  74 , and a releasable clamp or mounting structure  76  on the housing  74  that can be mounted to the skid steer loader vehicle  10 . The receiver module  66  comprises a housing  78 , a receiver/decoder  80 , a switching circuit  84 , a local power supply shown in the form of a battery  86 , a battery charger  88 , a wall plug transformer  90  and a battery charge indicator  92  for providing a visual indication of the electrical charge remaining in the battery  86 . The receiver module  66  has multiple electrical outlets or terminals  94   a - d  (FIG. 4) corresponding to the various channels of the wireless remote control system. The encoder/transmitter  72  is adapted to encode wireless transmissions in different channels based on the different manual input received at the operator input device  68 . The receiver/decoder  80  is adapted to receive encoded wireless transmissions and decode the transmissions for output in the respective channels.  
         [0037]    One embodiment of the receiver module  66  constructed in accordance with the teachings of the present invention is illustrated in simplified schematic form in FIG. 4 to which reference is now made. As illustrated in this FIG. 4, the battery  86  is coupled through a main power switch  98  and protective fuse  100  to the switching circuit  84 . The battery charger/monitor module  88  is also coupled to the battery  86  upstream of the main power switch  98  so that the battery  86  may be charged while the receiver module  66  is turned off. In one embodiment of the present invention, the battery charger/monitor module  88  is supplied with electric power from a wall plug transformer  90 , although one skilled in the art will recognize that such wall plug transformer  90  may not be required if the battery charger/monitor module  88  includes an input transformer. The battery monitor portion of the module  88  also provides an output to the charge indicators  92  that provide a visual indication of the electrical charge status of the battery  86 .  
         [0038]    The switching circuit  84  is also coupled to the receiver/decoder module  80 , which in this embodiment is illustrated as a four-channel receiver module such as that provided by Visitect under Part No. RF304RM. The switching circuitry for each output channel  94   a - d  is identical, and therefore the following description will describe only a single channel in the interest of brevity. However, one skilled in the art will recognize that the following description is equally applicable to the switching circuitry for each output channel, regardless of how many channels are provided in a particular embodiment.  
         [0039]    From a functional standpoint, the switching circuit  84  of the present invention is capable of providing various configurable outputs at each channel depending on the requirements of the controlled equipment to be coupled thereto. That is, each channel&#39;s output connector  94  contains three pins to which the controlled equipment may be coupled. One pin  102  provides a normally energized output through the normally closed contact of control switch  108 . The control of this switch  108  will be discussed more fully below. A second pin  104  provides a normally de-energized output via the normally open contact of switch  108 . The third pin  106  for each channel&#39;s output connector  94  provides the ground coupling. In addition to the provision of a normally energized and normally de-energized output connection at each channel, the switching circuitry for each channel also provides the ability of providing a latched or momentary output.  
         [0040]    To enable such functionality, a latching logic circuit such as the DQ Flip Flop 110 may be used. Specifically, when the receiver module  80  receives a control input for a particular channel, it generates an output on the appropriate channel control line  112 . This channel control line  112  is coupled to the clock input of the DQ Flip Flop 110. The output Q 114 of the DQ Flip Flop 110 is then coupled to jumper terminal block  116 . The channel control line  112  is also directly coupled to the jumper terminal block  116 . The jumper terminal block  116  also has an output pin  118  that is coupled to the control terminal of an electronic switch, for example, transistor  120 . When this pin  118  is energized, transistor  120  begins to conduct current therethrough. This energizes solenoid  122  to transition the control switch  108  from its normally closed to its normally open output configuration. When output pin  118  is not energized, the transistor  120  is turned off, and the control switch  108  returns to its quiescent state.  
         [0041]    Whether the control switch  108  is latched in its energized state or merely transitioned momentarily so long as the operator continues to transmit the control signal for this particular channel is dependant on the placement of a jumper on jumper terminal  116 . That is, if a jumper is placed between the output pin  118  and the input pin coupled to the output Q 114, operation of transistor  120 , energization of solenoid  122 , and therefore operation of switch  118  will be latching. However, if a jumper pin is placed between the output pin  118  of terminal  116  and the input connected to the channel control line  112 , then the transistor  120  and solenoid  122  will be energized so long as the receiver module  80  continues to receive the command input for that particular channel. Once the receiver module  80  no longer receives the control signal for this channel, it will de-energize the output control line  112  which will, through the jumper on jumper terminal  116  result in the transistor  120  being de-energized. This will stop the flow of current through solenoid  122  and will allow the control switch  108  to return to its quiescent position.  
         [0042]    As such, the output coupling  94  is not only selectable between a normally energized or normally de-energized configuration, but may also be configured to provide a latching control output or a momentary control output as discussed above. In the former configuration, the user need only briefly energize the transmitter for this particular channel to result in a latched output change, for example, to turn on the control equipment coupled thereto. When the user wishes to turn off the controlled equipment, he need only briefly retransmit a control signal for that channel, which will then cause the output to be de-energized. In the latter, momentary control configuration, the user must select and hold the control input for the particular channel to energize the connected equipment during the period that he transmits the control signal. When the user wishes to de-energize the controlled equipment, he need only release the transmitter. The absence of the transmitted control signal will result in the output being de-energized.  
         [0043]    Turning to FIG. 5, a second embodiment and application of the present invention is illustrated. It is similar in many respects to that illustrated in FIG. 1 and as such, only certain differences will be discussed for brevity. This embodiment is shown in the form of a cold planner work attachment  20   a  for the skid steer loader  10  and illustrates further aspects and versatility of the present invention. In this embodiment, the cold planner work attachment  20   a  includes multiple solenoid valves  42   a - 44   a,  with two channels or electrical lines  53   a - 58   a  provided for each solenoid valve, respectively. The transmitter module  64   a  and receiver module  66   a  are provided with at least six channels to support this application. Each solenoid valve  42   a - 44   a  is illustrated as a three position, four way valve with blocked over center position. Each solenoid valve  42   a - 44   a  has two solenoids  50   a  and two centering springs  48   a  to provide for the three illustrated positions of the valve. Each solenoid valve  42   a - 44   a  operates at least one hydraulic cylinder  30   a  for positioning the cold planner work tool  26   a,  with one of the solenoid valves  44   a  shown for operating two hydraulic cylinders  30   a.    
         [0044]    Like the first embodiment, flow in the hydraulic hoses  35   a,    37   a  need not be reversed but can be maintained to keep the system simple and responsive for the vehicle operator. Specifically, once the control valve  40  in the skid steer loader  10  is activated to provide hydraulic power to the attachment  20   a,  there is no need to move the control valve  40  to retract or move the cylinders in opposite directions. This can all be accomplished through the two channels for each of the solenoid valves  42   a - 44   a,  in which activation of one of the channels of a given solenoid valve drives the corresponding hydraulic cylinder(s) in one direction and activation of the other channel of the given solenoid valve drives the corresponding hydraulic cylinder(s) in a reverse direction. To accomplish the embodiment of FIG. 5, more channels or electrical lines  53   a - 58   a  (and therefore switching circuits for the channels) are provided. If desired, a solenoid valve and one or more channels may also be provided for the hydraulic motor  28   a  of the cold planner work attachment  20   a.    
         [0045]    Although the first two embodiments have describe the invention in context of solenoid valves utilizing two solenoids and therefore two channels, as noted above, it will be appreciated that the invention is applicable to applications having valves activated by only one solenoid and therefore valves in an application may utilize only a single channel, such as conventional on/off valves. Each on/off valve may be connected to a different hydraulic actuator. The on/off valve may turn on or shut off flow leading to a hydraulic motor for example. In the case of a hydraulic actuator, reversal of flow using the skid steer control valve  40  changes the direction of the hydraulic cylinder.  
         [0046]    [0046]FIG. 6 illustrates an embodiment of the wireless remote control kit  62  as used in the embodiment shown for FIGS.  1 - 4 . As will readily be appreciated, the existing wires on work attachments may be removed and replaced by installing this kit  62 . The kit  62  may also be installed as an option on new work attachments. The kit  62  includes a transmitter module  64  preferably contained within a single housing  74  (along with a local power supply), and a receiver module  66  preferably contained within a single housing  78  along with the switching circuit  84 , local power supply, charger, ect. The kit  62  is easily installed by mounting the receiver module  66  on the work attachment. The transmitter module  64  is sold along with the work attachment and then can be manually attached (and detached) or carried by the vehicle operator who purchases or rents the work attachment having the wireless remote control kit  62 . The transmitter module  64  includes a mounting structure  76  (e.g. a clamp, removable fasteners, hooks, Velcro straps, tape, magnets, ect.) for selective attachment (preferably temporary attachment) and detachment to the skid steer loader. As shown in FIG. 6, the transmitter module  64  may include multiple input buttons as the operator input device  68 , one for activating or energizing each different channel.  
         [0047]    Alternatively, and according to an alternative embodiment shown in FIG. 7, a transmitter module  124  may include an activation trigger  125  and a selector dial or switch  126 . According to this embodiment, the selector switch  126  can be rotated or moved between multiple discrete positions corresponding to the different channels, respectively. Thus, by moving the dial or selector switch  126 , the channel and therefore the hydraulic actuator(s) being controlled is switched. Activation of the trigger  125  energizes the channel designated by the dial or switch  126 . In this embodiment, the transmitter module has been configured as a handgrip with a sleeve housing  128  that slides upon or is otherwise mountable upon one of the control levers  17  in the cab of the skid steer loader  10 . The selector switch and trigger may also be provided in separate housings (with each housing be mountable to different convenient locations in the skid steer cab) with a wire running therebetween.  
         [0048]    All references, including publications, patent applications, and patents, cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein.  
         [0049]    The use of the terms “a” and “an” and “the” and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms “comprising,” “having,” “including,” and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to,”) unless otherwise noted. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.  
         [0050]    Preferred embodiments of this invention are described herein, including the best made known to the inventors for carrying out the invention. Variations of those preferred embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.