Apparatus for controlling the operation of a shift member and input clutch in a gear type transmission

Claim 1

Apparatus for the operational control of a shift member and an input clutch in a gear-type transmission, said apparatus comprising an operation cylinder for the shift member and an operation cylinder for the input clutch, a pressure fluid source, means providing a first passage and a second passage leading respectively to the operation cylinder for the shift member and the operation cylinder for the input clutch, manually operable valve means interposed in the first passage for selectively providing communication between the pressure fluid source and the operation cylinder of the shift member, the shift member being displaced by the pressure fluid from said source when the manually operable valve means is in active position and the source is in communication with the operation cylinder of the shift member, second valve means in said second passage for controlling flow of pressure fluid to said operation cylinder for said input clutch, the second valve means being operatively associated with said shift member to be automatically opened near the end of the displacement of the shift member whereby the input clutch will be operated subsequent to the shift member, a slidable piston in said operation cylinder for the shift member, a rod connecting said piston and shift member, said piston being subjected to said pressure fluid, with the manually operable valve means in active position, to be displaced thereby and thus cause displacement of the shift member, said second valve means being constituted by a portion of said rod having a peripheral groove providing communication to said second passage for the pressure fluid as the rod is displaced and the shift member approaches the end of its displacement, means providing a third passage leading to the operation cylinder for the shift member, the first and third passages opening into the operation cylinder for the shift member on opposite sides of said piston, said manually operable valve means being constructed to selectively connect the first and third passages to said source whereby the piston is double acting and the shift member can be displaced in opposite directions to two operative positions, and a valve chamber separate from said operation cylinders slidably accommodating said portion of the rod with the peripheral groove, said valve chamber having a first opening leading to one of said first and third passages, a second opening leading to said second passage, and a third opening leading to the other of said first and third passages, said openings being equally spaced apart in the direction of displacement of the rod, said groove being of a lengtH slightly exceeding said spacing whereby the second passage is alternately placed into communication with the first and third passage when the rod approaches its end of stroke positions corresponding to the operative positions of the shift member.