Patent ID: 7472649
Filing Date: 2009-01-06
Classification: A01F,B30B

Abstract:
1. In a large round baler including a discharge gate mounted for pivoting vertically between a lowered baling position and a raised discharge position, a pair of extensible and retractable gate cylinders coupled to said gate for selectively swinging the gate between said baling and discharge positions, a bale ejection ramp mounted at a location beneath said discharge gate for pivotal movement between a raised home position and a lowered ejection position, an extensible and retractable ramp cylinder coupled to said ramp for selectively moving said ramp between said home and ejection positions, and a hydraulic circuit including a control valve selectively shiftable among a neutral position, wherein the flow of fluid to and from the gate and ramp cylinders is blocked, a first operating position wherein pressure fluid is routed to first chambers of each of said gate and ramp cylinders for causing said gate cylinders and ramp cylinder to be shifted in respective first directions for effecting movement of said gate toward said discharge position and said ramp to said ejection position, and a second operating position wherein pressure fluid is routed to second chambers of each of said gate and ramp cylinders for causing said gate cylinders and ramp cylinder to be shifted in respective second directions for effecting movement of said gate toward said baling position and said ramp toward said home position, the improvement comprising: said hydraulic circuit including first and second pressure/return lines each coupled to said control valve, with said first pressure/return line including a first branch coupled to said first chamber of said ramp cylinder and containing a first pressure relief valve having a first cracking pressure setting, and including a second branch coupled to said first chambers of each of said gate cylinders and containing a second pressure relief valve having a second cracking pressure setting; said second relief valve being arranged to permit free flow of pressure fluid to said gate cylinders when said control valve is in said first operating position, while said first pressure relief valve is arranged for permitting flow to said ramp cylinder only after said first relief valve has opened which occurs only after the gate cylinders have moved the gate to its discharge position and the pressure in said first branch equals said first cracking pressure so as to cause said first relief valve to open; and said second pressure relief valve being arranged for preventing return flow from said first chambers of said gate cylinders, when said control valve is in said second operating position, until said ramp cylinder has moved said ramp to said home position and the pressure in second chambers of said gate cylinders has risen sufficiently to cause the pressure in said second chambers of said gate cylinders to equal said second cracking pressure so as to cause said second relief valve to open permitting said gate cylinders to move said gate to its baling position.