Control system for an automobile drive

Claim 1

In combination a hydrodynamic-mechanical transmission and a control system therefor, for use in an automobile having an accelerator pedal, a drive select lever having a plurality of positions, including forward drive, a source of first pressurized fluid, and a manual control valve, responsive to the position of said lever, for selectively delivering said first fluid when said select lever is in the forward drive position, wherein said transmission comprises: (a) a hydrodynamic torque converter having a hydraulically actuatable by-pass clutch; (b) a mechanical planetary gear train; and (c) at least one hydraulically actuatable control element for selectively coupling said torque converter and said gear train; and wherein said control system comprises: (i) a first pressure medium line adapted to be connected to said manual control valve for receiving said first pressurized fluid and communicating with said control element for supplying said first pressurized fluid to said element for actuating said control element, (ii) a main control valve means arranged in said first pressure medium line for selectively interrupting the delivery of said first fluid to said control element, (iii) means responsive to at least one automobile operating parameter for actuating said main control valve means, and (iv) means for delivering a pressurized fluid to said by-pass clutch for selectively actuating said by-pass clutch, wherein the means for delivering pressurized fluid to said by-pass clutch are responsive to the actuation of said main control valve means for interrupting the delivery of pressurized fluid to said by-pass clutch when said main control valve means is actuated.