Swath roller with controlled anchoring force

Abstract

A swath roller apparatus is adapted to be attached to a swather, where the swather is operative to cut standing crop plants and lay cut plants in a swath as the swather moves along the ground in an operating travel direction. A drum is rotatably attached to an axle that is adapted to be movably attached to a rear portion of the swather such that the axle is oriented substantially horizontally and perpendicular to the operating travel direction, and such that the drum moves up and down and rolls along a top of the swath exerting a downward anchoring force on the swath. A bias element is operative to exert a bias force on the axle, and a bias force control is operative to vary the bias force to vary the anchoring force.

What is claimed is: 
     
         1 . A swath roller apparatus for a swather, the swather operative to cut standing crop plants and lay cut plants in a swath as the swather moves along the ground in an operating travel direction, the apparatus comprising:
 a drum rotatably attached to an axle;   wherein the axle is adapted to be movably attached to a rear portion of the swather such that the axle is oriented substantially horizontally and perpendicular to the operating travel direction, and such that the drum moves up and down and rolls along a top of the swath exerting a downward anchoring force on the swath;   a bias element operative to exert a bias force on the axle; and   a bias force control operative to vary the bias force to vary the anchoring force.   
     
     
         2 . The apparatus of  claim 1  wherein the bias force control is adapted to be mounted at an operator's station of the swather. 
     
     
         3 . The apparatus of  claim 1  wherein the bias force is exerted in an upward direction on the axle to reduce the anchoring force. 
     
     
         4 . The apparatus of  claim 1  wherein the bias force is exerted in a downward direction on the axle to increase the anchoring force. 
     
     
         5 . The apparatus of  claim 1  wherein the bias element is provided by a hydraulic cylinder with a first port thereof connected to a pressurized hydraulic fluid source of the swather such that the bias force is directed in a first direction, the hydraulic fluid source configured such that a substantially constant bias pressure is maintained in the hydraulic cylinder to exert a substantially constant bias force, and such that hydraulic fluid moves into and out of the hydraulic cylinder through the first port in response to forces exerted on the hydraulic cylinder that are greater or less than the bias force. 
     
     
         6 . The apparatus of  claim 5  wherein the bias force control comprises a hydraulic control valve operative to vary the bias pressure in the hydraulic cylinder to vary the bias force. 
     
     
         7 . The apparatus of  claim 6  wherein the hydraulic valve is further operative to direct pressurized hydraulic fluid through a second port of the hydraulic cylinder such that the bias force is directed in a second direction opposite the first direction. 
     
     
         8 . The apparatus of  claim 7  wherein the hydraulic valve is operative to direct pressurized hydraulic fluid through one of the first and second ports at an increased bias pressure such that the drum is raised above the swath. 
     
     
         9 . The apparatus of  claim 1  wherein the axle is mounted in a drum frame, and wherein the drum frame is adapted to be pivotally attached to the rear portion of the swather about a drum frame axis oriented substantially parallel to the axle, and wherein the bias element is operative to exert the bias force on the drum frame. 
     
     
         10 . The apparatus of  claim 9  wherein the drum frame is pivotally attached to a trailer frame mounted on wheels, and the trailer frame is adapted to be attached to the rear portion of the swather. 
     
     
         11 . The apparatus of  claim 9  comprising right and left bias elements operative to exert substantially equal right and left bias forces on corresponding right and left sides of the drum frame. 
     
     
         12 . The apparatus of  claim 1  comprising right and left guide plates each defining a guide channel, the guide plates adapted to be attached to the rear portion of the swather such that the guide plates extend downward from the swather, and wherein right and left ends of the axle engage corresponding guide channels in the right and left guide plates. 
     
     
         13 . The apparatus of  claim 12  comprising right and left bias elements operative to exert substantially equal right and left bias forces on corresponding right and left ends of the axle. 
     
     
         14 . The apparatus of  claim 1  further comprising a stop limiting downward movement of the drum. 
     
     
         15 . A method of swathing a crop comprising:
 moving a swather along the ground in an operating travel direction such that the swather cuts standing crop plants and lays the cut plants in a swath behind the swather supported on standing stubble of the cut crop plants;   rotatably attaching a drum to a rear portion of the swather such that a rotational axis of the drum is oriented substantially horizontally and perpendicular to the operating travel direction;   allowing the drum to move up and down and roll along a top of the swath such that the drum exerts a downward anchoring force on the swath and pushes the swath into the standing stubble;   exerting a bias force on the drum and manipulating a bias force control to vary the bias force to vary the anchoring force in response to variations in the crop as the swather moves along the ground.   
     
     
         16 . The method of  claim 15  wherein the bias element is provided by connecting a first port of a hydraulic cylinder to a pressurized hydraulic fluid source of the swather such that the bias force is directed in one of an upward and downward direction, and manipulating the bias force control to vary a bias pressure in the hydraulic cylinder to vary the bias force, and allowing hydraulic fluid to move into and out of the hydraulic cylinder through the first port in response to forces exerted on the hydraulic cylinder that are greater or less than the bias force. 
     
     
         17 . The method of  claim 16  comprising directing pressurized hydraulic fluid through a second port of the hydraulic cylinder such that the bias force is directed in the other of the upward and downward directions. 
     
     
         18 . The method of  claim 17  comprising directing pressurized hydraulic fluid through one of the first and second ports at an increased bias pressure to raise the drum above the swath. 
     
     
         19 . The method of  claim 15  further comprising limiting downward movement of the drum to a lowest location where the drum is above the ground.