Patent Publication Number: US-2011077822-A1

Title: Remote control of sliding trailer suspension lock pins

Description:
TECHNICAL FIELD 
     The subject invention relates to a trailer sliding suspension with lock pins that can be controlled from a location remote from the sliding suspension. 
     BACKGROUND OF THE INVENTION 
     Trailers are used to transport large amounts of goods to various locations. The trailers are coupled to a vehicle, such as a semi-tractor for example, which then transports the trailer to a desired location. A significant portion of existing trailers utilize a sliding tandem suspension that includes a series of lock pins. The pins lock into trailer body side rails to fix the suspension to the trailer. The pins can be unlocked to adjust a position of the sliding suspension along the trailer. The position of the suspension is adjustable to change axle weight distribution, improve maneuverability, and/or to accommodate for unloading or loading of goods. 
     In order to reposition the sliding suspension, a driver must first exit a cab of the tractor and walk to a rear of the trailer to release/unlock the pins from the trailer side rails. The driver then returns to the cab and drives the tractor to reposition the sliding suspension by moving the trailer relative to the sliding suspension. Once the suspension is in the desired position, the driver must again exit the cab to re-engage the pins within corresponding holes in the trailer side rails. The driver then returns to the cab to ensure that the pins lock into the holes by slightly moving the suspension. Finally, the driver then exits the cab for a third time and walks to the rear of the trailer to visually confirm that all pins have engaged within the holes such that the suspension is securely locked in place. Such a procedure is time consuming and difficult especially when conducted during adverse weather conditions. 
     SUMMARY OF THE INVENTION 
     A trailer sliding suspension is remotely controlled in response to locking and unlocking requests. 
     In one example, to unlock the sliding suspension, a user generated first signal is communicated to an electronic control unit of a trailer anti-lock brake system. The electronic control unit then generates an unlocking signal in response to the first signal to unlock the sliding suspension such that a position of the sliding position can be adjusted relative to a trailer supported by the sliding suspension. Once the sliding suspension is in the desired position, a second signal is generated which is communicated to the electronic control unit. The electronic control unit then generates a locking signal in response to the second signal to lock the sliding suspension to a trailer body rail. 
     In one example, a trailer sliding suspension includes at least one lock pin that is movable between a locked position where the lock pin engages in an opening in the trailer body rail and an unlocked position where the lock pin is disengaged from the trailer body rail. A peripheral device is configured to control movement of the lock pins in response to the unlocking and locking signals. 
     These and other features of the present invention can be best understood from the following specification and drawings, the following of which is a brief description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a side view of a tractor-trailer vehicle incorporating a trailer sliding suspension. 
         FIG. 2  is a schematic diagram of a control system for the trailer sliding suspension which incorporates the subject invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     A tractor  10  is coupled to a trailer  12 , which is used to transport goods to a desired location. The tractor  10  includes a front steer axle  14  and a tandem rear drive axle  16  over which a front portion of the trailer  12  extends. The front steer axle can comprise a non-drive or drive axle, and optionally, a single rear drive axle or a tridem rear drive axle can be used. A rear portion of the trailer  12  is supported on a set of trailer axles  18 . A trailer sliding suspension  20  is used to support this rear portion of the trailer  12  at the trailer axles  18 . The trailer sliding suspension  20  can comprise a sliding single, tandem, or tridem trailer suspension depending on the rear axle configuration. The figures show a sliding tandem trailer suspension as an example with the understanding that the sliding single and tridem trailer suspension would operate in a similar manner. 
     The trailer sliding suspension  20  is movable between a locked position and an unlocked position. When in an unlocked position, a driver can drive the tractor  10  to adjust a position of the sliding suspension  20  along a length of the trailer  12 . Once the sliding suspension  20  is at the desired position relative to the trailer  12 , the sliding suspension  20  is then returned to the locked position. 
     A highly schematic representation of one example of a trailer sliding suspension  20  is shown in  FIG. 2 . The sliding suspension  20  includes at least one locking pin  22  that is received within an opening  24  formed in a trailer body rail  26 . In the example shown, a plurality of lock pins  22  are utilized with a pair of trailer body rails  26 , which are located on opposing sides of the trailer  12 . The body rails  26  include a plurality of openings  24 . The lock pins  22  are moveable between a locked position wherein each pin  22  is received within one opening  24  and an unlocked position where the pins  22  are moved out of the openings  24 . When in the unlocked position the trailer  12  is moved relative to the sliding suspension  20  such that the lock pins  22  are aligned with a different set of openings  24 . When the sliding suspension  20  is in the desired position relative to the trailer  12 , the pins  22  are then re-engaged within the respective aligned openings  24  in the trailer body rails  26  to lock the suspension  20  securely in place. 
     A control system  30  is used to control locking and unlocking movement of the lock pins  22  of the trailer sliding suspension  20 . The control system  30  is configured to allow this movement to be controlled from a location that is remote from the trailer sliding suspension  20 . This is beneficial compared to traditional control systems which require the driver to walk back to the sliding suspension to manually initiate locking and unlocking movement of the pins  22 . It should be understood that the trailer sliding suspension  20  schematically shown in  FIG. 2  is just one example of a sliding suspension configuration and the control system  30  can be used to control any type of trailer sliding suspension. 
     The control system  30  comprises an electronic control unit (ECU)  32  from a trailer anti-lock brake system (TABS)  34 . The ECU  32  generates output signals  36  to control trailer brakes  38  in response to braking requests. The ECU  32  includes one or more additional 12 volt outputs  40  that are used to run peripheral devices. 
     In one example, one peripheral device comprises an actuator  42  that is electrically connected to an output  40  and is used to control operation of a control  44  that controls movement of the lock pins  22 . In one example, the control  44  comprises a pneumatic controller in fluid communication with an air supply  46  that can either be a dedicated air supply or part of the TABS  34 . In one example, the actuator  42  comprises an electric solenoid that is used to operate the pneumatic controller; however, other types of actuators could also be used. 
     To adjust a position of the sliding suspension  20 , the driver initiates an unlocking request which is communicated to the ECU  32 . In one example, the driver actuates an input device  50  which generates a first signal  52  which is communicated to the ECU  32 . 
     In one example, the first signal is generated from the input device  50  in response to the driver performing a predefined vehicle operation a specified number of times within a predetermined period of time. In one example, the input device  50  is located within a cab of the tractor  10  and can be one of many different types of inputs such as a brake pedal for example. The brake pedal is quickly and repeatedly depressed after a parking brake  60  has been set. In one example, the brake pedal is depressed at least three times within a short period of time comprising ten seconds or less. Once the pedal has been depressed the correct number of times within the specified time period, the first signal  52  is communicated to the ECU  32 . 
     In response to receipt of the first signal  52 , the ECU  32  generates an unlocking signal which is communicated to the actuator  42 , which in turn controls the pneumatic control  44  of the sliding suspension  20  to move the lock pins  22  to the unlocked position. This occurs while the driver remains in the cab. Once the pins  22  have been unlocked, the driver can then move the trailer  12  relative to the sliding suspension  20  to locate the sliding suspension  20  at a desired location along the trailer  12 . 
     Once the sliding suspension  20  is in the correct location, the driver initiates a locking request which is communicated to the ECU  32 . In one example, the driver actuates the input device  50  which generates a second signal  62  that is communicated to the ECU  32 . The second signal  62  can be generated through a manner similar to that for the unlocking signal, i.e. depressing the brake pedal a minimum number of times within a specified time period, or another type of driver input can be used to generate the second signal  62 . 
     In response to receipt of the second signal  62 , the ECU  32  generates a locking signal which is communicated to the actuator  42 . The actuator  42  then controls the pneumatic control  44  to re-engage the lock pins  22  within the openings  24  to securely lock the sliding suspension  20  to the body rails  26 . Only after the sliding suspension  20  has been re-locked, does the driver have to then exit the cab to visually verify that the pins are properly engaged within the openings. 
     It should be understood that the ECU  32  of the TABS  34  is pre-programmed with software to recognize the first and second signals initiated by driver actions such that the ECU  32  can then provide 12 volts to the appropriate output  40  to control the actuator  42 . In this manner, the driver can control movement of the lock pins from the cab in a simple and effective way without requiring expensive add-on devices. 
     Although a preferred embodiment of this invention has been disclosed, a worker of ordinary skill in this art would recognize that certain modifications would come within the scope of this invention. For that reason, the following claims should be studied to determine the true scope and content of this invention.