Control for mechanical transmission

Claim 1

A control for a transmission having multiple input portions and multiple output portions in which a plurality of speed ratios are provided by actuating selected pairs of input and output portions, comprising: a pair of shift rails; an axially movable and rotatable control shaft; a pair of cam members mounted on the control shaft so as to move and rotate therewith; each shift rail having a cam follower surface; one of the cam members positioned on the control shaft so that it is aligned with the cam follower surface of one of the shift rails when the other of the cam members is positioned to be aligned with the other of the shift rails; the one cam member adapted to cooperate with the cam follower surface of the one shift rail to effect movement of the respective shift rail upon rotation of the control shaft in a chosen direction whereby one of the input portions is actuated; the other cam member adapted to cooperate with the cam follower surface of the other shift rail to effect movement of the respective shift rail upon said rotation of the control shaft in a chosen direction whereby one of the output portions is actuated; and the movement of the one shift rail commences before and terminates during the movement of the other shift rail whereby the movements of the pair of shift rails are overlapped during rotation of the control shaft.

Claim 10

A method for moving shift rails in a transmission to effect speed ratio changes comprising the following steps: providing the transmission with a rotatable control shaft; mounting first and second cam members on the control shaft so as to rotate in unison with the control shaft; equipping a first rail with a first cam follower surface which is adapted to cooperate with said first cam member for operation of the first shift rail according to a predetermined first pattern when said control shaft is rotated through a selected arc, said first pattern including an interval when it does not move; equipping a second rail with a second cam follower surface adapted to cooperate with said second cam member for operation of the second shift rail according to a predetermined second pattern when said control shaft is rotated through said selected arc, said second pattern including an interval when said second rail moves and another interval when it does not move, said rail movement intervals overlapping whereby said two rails both move for only a portion of said arc; and rotating said control shaft through said arc.

Claim 11

A method for moving shift rails in a transmission to effect speed ratio changes comprising the following steps: providing the transmission with a rotatable control shaft; mounting first and second cam members on the control shaft so as to rotate in unison with the control shaft; equipping a first rail with a first cam follower surface which is adapted to cooperate with said first cam member for operation of the first shift rail according to a predetermined first pattern when said control shaft is rotated through a selected arc, said first pattern including an interval when it does not move; equipping a second rail with a second cam follower surface adapted to cooperate with said second cam member for operation of the second shift rail according to a predetermined second pattern when said control shaft is rotated through said selected arc, said second pattern including an interval when said second rail moves and another interval when it does not move, said rail movement intervals overlapping whereby said two rails both move for only a portion of said arc; and rotating said control shaft through said arc.