Abstract: Seal rings are set in oil grooves which are situated at both sides of two oil passages communicating two hydraulic actuators which operate oppositely. First and second seal rings oil-tightly seal between the first oil passage and sleeve, while third and fourth seal rings oil-tightly seal between the second oil passage and the sleeve. Accordingly even if oil flows oppositely in each of two oil passages due to the opposing motions of the two contiguous hydraulic actuators, not oil leakage occurs. Furthermore, a draining groove is situated between the oil grooves in which the second and third seal rings are installed.

Abstract: Thrust force generated by a hydraulic actuator is absorbed in a attachment device for a four speed automatic transmission mechanism. When hydraulic pressure is applied to the hydraulic actuator to engage a third and a fourth clutches, pressing force from a piston works on a strut member situated between the third and fourth clutches as a compression force, while a force working on a drum member as a tension force, so that these forces are counterbalanced and absorbed in the attachment device. Consequently, one directional move of the attachment device is supported by a little force such as contacting a snap ring and a thrust washer to a clutch drum, on the other hand, another move of the attachment device is supported by a little force such as connecting the drum member and a big ring gear by a snap ring.

Abstract: A governor valve for a hydraulic controller in an automatic transmission, which is disclosed herein, comprises an adapter having a line pressure supply bore made therethrough, a cylindrical governor rotary shaft loosely fitted into the adapter sleeve and having a line pressure supply port made therein, the port including notches intersecting the axis at right angles, a centrifugal weight mounted on one end of the governor rotary shaft and having a return spring, and a spool adapted to slide within the governor rotary shaft with the weight being urged against one end thereof. In this governor valve, there are provided dirt and dust collecting means for preventing dirt and dust separated by a centrifugal action from collecting in the line pressure supply port during the stoppage of the governor rotary shaft so as to make the shaft stick.