Bucket positioner for loaders

Claim 1

A vehicle comprising a work implement movably mounted on said vehicle, positioning means, including a fluid-actuated cylinder having a rod reciprocally mounted therein, for selectively moving said work implement upon extension or retraction of said cylinder, control means, including a multi-directional control valve having releasable mechanical holding means operatively associated therewith for maintaining said control valve in a first condition of operation for selectively communicating pressurized hydraulic fluid from a pressurized fluid source to said cylinder, and release means for releasing said holding means upon extension of said rod comprising first pilot means operatively directly connected to said rod to be actuated thereby upon extension thereof and second pilot means oepratively connected between said first pilot means and said directional control valve to actuate said directional control valve to release said holding means in response to actuation of said first pilot means, said work implement being a loader bucket pivotally mounted on the forward end of lift arm means, said lift arm means pivotally mounted on a frame of said vehicle, said positioning means including tilt linkage means operatively connected between said lift arm means and said loader bucket for selectively pivoting said loader bucket on said lift arm means, said cylinder constituting a double-acting cylinder, said control means further including a manually manipulatable handle directly pivotally attached to a spool member of said directional control valve for directly mechanically moving said spool member to actuate said control means, said releasable holding means comprising springloaded detent means operatively disposed for directly engaging said spool member, said first pilot means including an extensible cable means having a first end directly attached to said rod and a second end directly attached to a spool member of a pilot valve thereof, said pilot valve including a two-position, two-way directional control valve and a pressurized source of pneumatic fluid operatively communicable through said control valve upon actuation thereof by said cable means, said second pilot means including a pilot cylinder operatively connected to said pneumatic valve and having a piston reciprocally mounted therein to directly mechanically engage and move said spool member of said directional control valve upon extension of said rod.