Patent ID: 7823803

Claim:
A boom assembly for a self-propelled sprayer comprising: a boom frame including first and second pivotal mounting brackets adapted to couple with first and second swingable booms, respectively, such that pivoting of each bracket corresponds with swinging of an associated one of the booms; and first and second integrated cylinders, each of the first and second cylinders including a lower attachment pivotally connected to the boom frame and an upper attachment pivotally connected to a respective one of the mounting brackets so that overall extension and retraction of the integrated cylinder pivots the respective mounting bracket in a manner configured to correspond with folding and extension of the associated boom, each of said cylinders including a first stage cylinder and a second stage cylinder that define respective first and second fluid chambers, said first stage cylinder including a piston reciprocally disposed within the first fluid chamber and operably coupled between the attachments so that fluid flow into and out of the first fluid chamber causes reciprocation of the piston to adjust the overall length of the integrated cylinder and thereby pivot the respective mounting bracket to a desired position, said second stage cylinder being configured to releasably maintain a volume of fluid within the second fluid chamber, whereby the respective mounting bracket is removably retained in the desired position, and to permit fluid to flow from the second chamber when the pressure within the second fluid chamber exceeds a predetermined pressure level, whereby the pressure is relieved and the respective mounting bracket is permitted to pivot away from the desired position, said first and second fluid chambers being fluidly isolated from one another so that fluid from one chamber is prevented from passing into the other chamber, said volume of fluid within the second fluid chamber being undisturbed by reciprocation of the piston within the first fluid chamber.