Split Walking Beams for Raising and Lowering Respective Sides of a Vehicle or Implement Frame to Control a Tilt Angle or Height Thereof

Abstract

Vehicles or implements feature walking beam assemblies each having a front wheel and rear wheel carried adjacent opposite ends of the walking beam on opposite sides of a pivot point thereof. The conventional single beam is replaced by a split beam arrangement in which front and rear beams are pivotal relative to one another by an actuator, whereby changing the angle between the front and rear beams lifts or lowers the main pivot of the walking beam in order to adjust the height of the respective side of the vehicle frame. The split walking beam can be used to adjust the tilt angle of a scraper blade or other ground working arrangement in a land leveler or other earth working machine.

1 . A vehicle or implement comprising:
 a frame situated having opposing sides disposed on opposing sides of a longitudinal plane that runs in a longitudinal direction of the vehicle or implement;   a pair of wheel assemblies, each being attached to the frame adjacent a respective one of the opposing sides thereof so as to reside on and rollably carry a respective one of the opposing sides of the longitudinal plane, at least one of the wheel assemblies comprising:
 a split walking beam assembly pivotally coupled to the frame for pivotal movement of the split walking beam assembly about a first walking beam pivot axis lying transversely to the longitudinal direction, the split walking beam assembly comprising:
 a front beam having front and rear ends spaced apart in the longitudinal direction; and 
 a rear beam having forward and rearward ends spaced apart in the longitudinal direction, the front end of the front beam being situated forwardly of the forward end of the rear beam in the longitudinal direction, the rearward end of the rear beam being situated rearwardly of the rear end of the front beam in the longitudinal direction, the front and rear beams being coupled together adjacent the rear and forward ends thereof, and the rear beam being pivotal relative to the front beam about a second walking beam pivot axis lying transversely of the longitudinal direction; 
 
 a front wheel rotatably coupled to the front beam adjacent the front end thereof; 
 a rear wheel rotatably coupled to the rear beam adjacent the rearward end thereof; and 
 a wheel assembly actuator coupled between the front and rear beams of the split walking beam assembly and operable to pivot the front and rear beams relative to one another to adjust an angle measured between the front and rear beams at an underside thereof, whereby an increase of the angle lowers the respective side of the frame and respective lateral end of the blade and a decrease of the angle raises the respective side of the frame and the respective lateral end of the blade. 
   
     
     
         2 . The vehicle or implement of  claim 1  comprising:
 a tongue having fore and aft ends spaced apart in the longitudinal direction; 
 a hitch connector at the fore end of said tongue for coupling of the hitch connector to a hitch of a towing vehicle; 
 a ground working arrangement coupled to the tongue adjacent the rear end thereof with opposing lateral ends of the ground working arrangement disposed on opposing sides of the longitudinal plane of the vehicle or implement at outboard positions spaced laterally from said longitudinal plane; 
 wherein the frame is situated behind the ground working arrangement in the longitudinal direction, whereby increasing the angle of each wheel assembly lowers the respective lateral end of the ground working arrangement and decreasing the angle raises the respective lateral end of the blade of the ground working arrangement. 
 
     
     
         3 . The vehicle or implement of  claim 2  further comprising:
 a pivotal connection between the frame and the ground working arrangement that allows relative pivoting between the frame and the ground working arrangement about a pitch axis that lies in the transverse direction; and 
 a pitch actuator coupled between the frame and the blade and operable to tilt the ground working arrangement relative to the frame about the pitch axis. 
 
     
     
         4 . The vehicle or implement of  claim 2  wherein the frame comprises a cross-member lying transversely to the longitudinal plane and a pair of rearward reaching frame members extending therefrom in the longitudinal direction adjacent opposing ends of the cross-member on the opposing sides of the longitudinal plane, each rearward reaching frame member having a respective one of the wheel assemblies connected thereto and split walking beam assembly being pivotally connected to the respective rearward reaching frame member. 
     
     
         5 . The vehicle or implement of  claim 4  wherein the rearward reaching frame members are respectively connected to the cross-member at opposing ends thereof, and each extend forwardly past the cross-member to attach to the ground working arrangement. 
     
     
         6 . The vehicle or implement of  claim 2  wherein the ground working arrangement comprises a scraper blade lying transversely of the longitudinal plane with opposing ends of the blade defining the lateral ends of the ground working arrangement on the opposing sides of the longitudinal plane. 
     
     
         7 . The vehicle or implement of  claim 1  wherein the wheel assemblies both comprise a respective walking beam assembly, and the walking beam assemblies are arranged to be adjustable into different respective angles, thereby adjusting an angular position of the frame about a roll axis that extends in the longitudinal direction. 
     
     
         8 . The vehicle or implement of  claim 7  comprising a control system operable to control movement of the wheel assembly actuators. 
     
     
         9 . The vehicle or implement of  claim 8  wherein the control system is arranged to automatically extend one of the walking beam actuators while collapsing the other, thereby increasing the angle between the front and rear beams of one walking beam assembly while decreasing the angle between the front and rear beams of the other walking beam assembly so as to raise one side of the frame while lowering the other side of the frame. 
     
     
         10 . The vehicle or implement of  claim 9  wherein:
 each walking beam actuator comprises a hydraulic cylinder with a respective extension port and respective retraction port; 
 the control system comprises a four-way, three-position, spring centered directional valve with a pressure port for coupling to the output of a hydraulic pump, a return port for coupling with a hydraulic fluid reservoir, and a pair of output ports connected to either the extension ports or the retraction ports of the walking beam actuators; and 
 a hydraulic connection line coupling together the other of the extension ports or the retraction ports of the walking beam actuators. 
 
     
     
         11 . The vehicle or implement of  claim 10  wherein the directional valve is a double solenoid directional valve arranged to use electronic signals to control a position of the valve. 
     
     
         12 . The vehicle or implement of  claim 8  comprising a monitoring system arranged to monitor an orientation of the frame about a longitudinal axis, and linked to the control system to automatically control the walking beam actuators and adjust the orientation of the frame. 
     
     
         13 . The vehicle or implement of  claim 1  wherein the first walking beam pivot axis and second walking beam pivot axis of each wheel assembly are coincident with one another. 
     
     
         14 . The vehicle or implement of  claim 1  wherein the first and second beams of each wheel assembly both pivot about the second walking beam pivot axis. 
     
     
         15 . A method of providing tilt or height adjustment capabilities to a vehicle or implement that is at least partially supported by a pair of walking beam wheel assemblies are disposed on opposing sides of a longitudinal plane of the vehicle or implement and each feature front and rear wheels that are respectively mounted adjacent front and rear ends a single walking beam that is pivotally coupled to a frame of the vehicle or implement at a longitudinally intermediate location on the walking beam for pivoting of the walking beam about a walking beam pivot axis lying transversely to the central longitudinal plane, the method comprising:
 replacing at least one walking beam assembly with a respective split walking beam assembly that is pivotally coupled to the frame for movement about the same walking beam pivot axis, and that comprises:
 a front beam having front and rear ends spaced apart in a longitudinal direction in which the central longitudinal plane extends; and 
 a rear beam having forward and rearward ends spaced apart in the longitudinal direction, the front end of the front beam being situated forwardly of the forward end of the rear beam in the longitudinal direction, the rearward end of the rear beam being situated rearwardly of the rear end of the front beam in the longitudinal direction, the front and rear beams being coupled together adjacent the rear and forward ends thereof, and the rear beam being pivotal relative to the front beam about a second pivot axis lying transversely of the longitudinal direction; 
 a front wheel rotatably coupled to the front beam adjacent the front end thereof; 
 a rear wheel rotatably coupled to the rear beam adjacent the rearward end thereof; and 
   a wheel assembly actuator coupled between the front and rear beams of the split walking beam assembly and operable to pivot the front and rear beams relative to one another to adjust an angle measured between the front and rear beams at an underside thereof, whereby, with the front and rear wheels on a ground surface, an increase of the angle surface lowers the respective side of the frame and respective lateral end of the blade and a decrease of the angle raises the respective side of the frame and the respective lateral end of the blade.   
     
     
         16 . The method of  claim 15  comprising replacing each walking beam assembly with a respective split walking beam assembly, and further comprising equipping the vehicle or implement with a control system operable to control movement of the wheel assembly actuators. 
     
     
         17 . The method of  claim 16  wherein the control system is arranged to extend one of the walking beam actuators while collapsing the other, thereby increasing the angle between the front and rear beams of one walking beam assembly while decreasing the angle between the front and rear beams of the other walking beam assembly so as to raise one side of the frame while lowering the other side of the frame. 
     
     
         18 . The method of  claim 17  wherein each walking beam actuator comprises a hydraulic cylinder with a respective extension port and respective retraction port and the control system comprises a four-way, three-position, spring centered directional valve, the method comprises coupling a pressure port of the directional valve to an output of a hydraulic pump, coupling a return port of the directional valve with a hydraulic fluid reservoir, fluidly connecting output ports of the directional valve to either the extension ports or the retraction ports of the walking beam actuators, and fluidly connecting the walking beam actuators together at the other of the extension ports or the retractions ports. 
     
     
         19 . The method of  claim 18  wherein the directional valve is a double solenoid directional valve arranged to use electronic signals to control a position of the valve. 
     
     
         20 . The method of  claim 16  comprising equipping the vehicle or implement with a tilt monitoring system arranged to monitor an angular position of the frame about a roll axis that extends in the longitudinal direction, and connecting the tilt monitoring system to the control system to automatically control the walking beam actuators and adjust the angular position. 
     
     
         21 . The method of  claim 15  wherein the second pivot axis of each split walking beam assembly is coincident with the respective walking beam pivot axis. 
     
     
         22 . The method of  claim 15  wherein the first and second beams of each split walking beam assembly both pivot about the second pivot axis. 
     
     
         23 . A towable ground working implement comprising:
 a tongue having fore and aft ends spaced apart in a longitudinal direction;   a hitch connector at the fore end of said tongue for coupling of the hitch connector to a hitch of a towing vehicle;   a scraper blade coupled to the tongue adjacent the rear end thereof and lying transversely to the longitudinal direction so as to place opposite lateral ends of the blade on opposing sides of a central longitudinal plane of the implement at outboard positions spaced laterally from said central longitudinal plane;   a frame situated behind the blade in the longitudinal direction with opposite sides of the frame disposed on the opposing sides of the longitudinal plane;   a pair of wheel assemblies, each being attached to the frame adjacent a respective one of the opposing sides thereof so as to reside on a respective one of the opposing sides of the longitudinal plane, at least one of the wheel assemblies comprising:
 a split walking beam assembly pivotally coupled to the frame for pivotal movement of the split walking about a first walking beam pivot axis lying transversely to the longitudinal direction, the split walking beam assembly comprising:
 a front beam having front and rear ends spaced apart in the longitudinal direction; and 
 a rear beam having forward and rearward ends spaced apart in the longitudinal direction, the front end of the front beam being situated forwardly of the forward end of the rear beam in the longitudinal direction, the rearward end of the rear beam being situated rearwardly of the rear end of the front beam in the longitudinal direction, the front and rear beams being coupled together adjacent the rear and forward ends thereof, and the beam being pivotal relative to the front beam about a second walking beam pivot axis lying transversely of the longitudinal direction; 
 
 a front wheel rotatably coupled to the front beam adjacent the front end thereof; 
 a rear wheel rotatably coupled to the rear beam adjacent the rearward end thereof; and 
 a wheel assembly actuator coupled between the front and rear beams of the split walking beam assembly and operable to pivot the front and rear beams relative to one another to adjust an angle measured between the front and rear beams at an underside thereof, whereby, with the front and rear wheels on a ground surface, an increase of the angle lowers the respective side of the frame and respective lateral end of the blade and a decrease of the angle raises the respective side of the frame and the respective lateral end of the blade, thereby adjusting an angular tilt position of the blade about a roll axis that extends in the longitudinal direction.