Abstract: An electro-pneumatic door control apparatus for use on public vehicles and including reversing mechanism for changing the direction of door movement, either automatically or operator-initiated, in the event of an obstruction in the door. The control apparatus further includes a flip-flop for recording the position (either open or closed) of the door at all times, a monitoring logic device for recognizing the position of the flip-flop and what type of monitoring function is permitted, a control logic device for picking up the door command and the signal from the monitoring logic device combing them and transmitting them to a valve solenoid control device for energizing respective solenoids of several valve devices by which the appropriate movement of the doors is effected.

Abstract: The servovalve includes a primary jet of fluid. A variable control signal is adapted to vary the angular position of the primary jet from its maximum recovery position. A first fluid path is adapted to supply fluid to a servopiston at a variable pressure determined at least in part by the control signal. A second fluid path is adapted to receive a predetermined portion of the primary jet fluid when the control signal reaches a predetermined value. The second fluid path terminates in the vicinity of the primary jet and is adapted to direct a secondary jet of fluid at the primary jet to deflect the primary jet toward the input orifice of the second fluid path. The resultant positive fluid feedback in the second fluid path causes the primary jet to latch in a first angular position relative to the maximum recovery position when the control signal reaches a predetermined value.

Abstract: A negative pressure type booster arrangement comprises a pair of booster shells divided by a booster piston disposed therein for reciprocating movement into a constantly negative pressure chamber and a variable pressure chamber. The second chamber is always put in interchangeable communication with the first chamber via a control valve mechanism. An input rod is retractively connected to the booster piston, and is also connected to the valve control mechanism for permitting the booster piston to follow advancement of the input rod due to a difference in air pressure between both chambers. An input transmitting lever is mounted on the rear end of the input rod. A first arm is provided for supporting an operating lever extending successively from the booster shells and for pivotally supporting one end of the input transmitting lever, and a second arm is provided for supporting an operating wire.

Abstract: A redundant swashplate control system includes five or more actuators coupled to the swashplate. A feedback network independently controls each actuator to track a commanded position and a reference ram differential pressure that it related to the ram differential pressures sensed from all of the actuators.

Abstract: In order to reduce the forces transmitted by the reaction device of a vacuum brake booster, there is provided a first booster piston directly connected to the booster's output member and a second booster piston of smaller size acting solely on the reaction device. Both booster pistons are controlled by a control valve carried by the second booster piston. The second booster piston is arranged inside an internal cylindrical sleeve penetrating the first booster piston and interconnecting the transverse end walls of the booster housing.

Abstract: A power steering system has a servomotor flow control valve with means for automatically returning the vehicle to straight ahead position by hydraulic power. This is accomplished in a construction utilizing a piston valve linked by a cam mechanism to movement of a servomotor piston in such manner that, responsive to movement of the servomotor piston, and upon return of the piston valve to a neutral position a brief overtravel beyond neutral position occurs which reversely pressurizes the servomotor to straighten the wheel direction after a turn.

Abstract: A pumping unit for actuating a linear reciprocable pump rod comprises a frame having a pair of spaced apart vertical guides for guiding vertical reciprocating movement of a traveling pulley assembly connected to a linear extensible hydraulic cylinder mounted on the frame directly under the pulley assembly. The pulley assembly includes two rotatable sheaves over which are trained, respectively, flexible cables which are anchored at their opposite ends to the frame and to a bracket connected to the pump rod. The arrangement provides a single purchase pulley system providing for a pump rod stroke length of twice the stroke length of the cylinder actuator. A hydraulic control system for reciprocating the cylinder includes a solenoid operated valve which is controlled by a cam actuated switch to alternately provide for conducting hydraulic fluid to and from the cylinder. The valve actuating switches are tripped by spaced apart cams mounted on a rod connected to the pulley assembly.

Abstract: To reduce the overall weight of mechanically controlled brake boosters it is known to transmit the axial reaction forces by means of axial draw bars or pipes extending axially within the booster housing. According to the present invention the weight reduction and a decrease in axial length of the brake booster is accomplished having the booster housing shaped like a ring which surrounds and is connected to the maste brake cylinder. The master brake cylinder is fastened to the vehicle splashboard via axial webs extending beyond a lateral wall of the booster housing. A yoke arranged movably between the splashboard and the booster housing contains the valve mechanism and transmits the boosting force from the booster piston (movable wall) to the piston of the master brake cylinder.