Patent ID: 7265304

Claim:
A joystick for an electro-hydraulic control system, said joystick being provided with: a control member pivotally controllable by an operator in a predetermined direction or in a direction opposite to said predetermined direction; a rocking means rockable as a result of pivotal control of said control member; a support pin supporting said rocking means thereon; a rotary potentiometer having a rotary shaft rotatable as a result of a rocking motion of said rocking means, said rotary potentiometer being capable of outputting a rotation angle signal responsive to rotation of said rotary shaft; an extension arm arranged integrally on said support pin and extending toward said rotary potentiometer; a pivotable arm connected to said extension arm pivotably within a vertical plane parallel to a plane in which a range of pivotal movements of said extension arm is included, and arranged integrally on said rotary shaft of said rotary potentiometer; a linkage connecting said pivotable arm and said extension arm together with predetermined clearances interposed therebetween in said predetermined direction and opposite direction in which said control member can be controlled; a torsion coil spring for normally holding said pivotable arm of said rotary potentiometer in a neutral position; an expanding means arranged on said pivotable arm to expand said torsion coil spring upon pivotal movement of said pivotable arm; and a holding pin arranged on said rotary potentiometer and holding said torsion coil spring at a coil portion thereof, wherein: said joystick is provided with a means for limiting movements of said coil portion of said torsion coil spring in said predetermined direction and said opposition direction when said torsion coil spring is in a neutral position.