Automatic valve control mechanism for vehicle mounted implements

Claim 1

In a vehicle having implement means mounted on pivotal support means and adapted to be raised by a hydraulic jack means pivotally connected to the vehicle, a valve for directing fluid to said jack means upon movement of the valve away from a neutral position to raise the implement, detent means to hold said valve means in a position for operating the jack means so as to raise the implement, and means to disengage the detent means so as to allow the valve to return to its neutral position when the implement reaches a predetermined position, said last named means including a valve-actuating lever, a control link assembly comprising a connecting link means responsive to implement position, and a lost-motion link means, said lost motion link means allowing movement of said connecting link means which is unrestrained and unbiased by said lost-motion link means for a finite distance corresponding with the raising of the implement to said predetermined position whereupon said lost-motion link means is operable upon the implement reaching said predetermined position to disengage the detent means whereby said valve returns to its neutral position to hold said implement at said predetermined position, said lost-motion link means further including biasing means providing biased travel after the implement has reached said predetermined position for a further finite distance whereby said lost-motion link means may be manually overriden by movement of said valve actuating lever against the force of said biasing means so as to further raise the implement beyond the predetermined position, said biasing means further operating to return said valve actuating lever and thereby said valve to the neutral position upon manual release of said valve actuating lever and wherein said lost-motion link means comprises a housing having means adjustably securing the housing to a first rod member of said control link assembly, said biasing means comprising a spring contained within said housing, a second rod member of said control link assembly, one end of said second rod member being received in said housing and having means thereon whereby movement of said second rod member incideNt to overriding the lost-motion link means causes the spring to be compressed.