Vacuum-suspended tire servo-motor
AssigneeNisshin Kogyo Kabushiki Kaisha
InventorHiroo Takeuchi
Life of this patent
Estimating the term…
Abstract
A servo-motor including control valve and reaction means of novel design is provided which has improved operation characteristics with a minimum of hysteresis, enabling the driver to lightly operate a brake or other associated system while accurately feeling the reaction therefrom. The control valve means precludes any loss of vacuum from a first power chamber as may otherwise occur when a second power chamber is placed into communication with the atmosphere and, eliminating the need for sealing means as arranged around an input member extending through a movable wall of the servo-motor, minimizes the resistance to axial sliding movement of the input member. The motor structure is simplified and includes a minimum number of component parts.
Claims3
A servo-motor of the vacuum-suspended type including:
- a casing structure and a movable wall member dividing the casing structure into a front, first power chamber to which vacuum is always communicated and a rear, second power chamber;
- an input member slidably fitted in said movable wall member;
- an output member operatively connected with said movable wall member on the front side thereof;
- and
- control valve means operatively connected with said input member and adapted to selectively place said second power chamber into communication with said first power chamber and the external atmosphere;
- said control valve means comprising:
- a tubular valve casing integral with said movable wall member on the rear side thereof and slidably supported by the rear wall of said casing structure, said valve casing having a front end wall constituting part of said movable wall member and opening at the rear end to the external atmosphere;
- a first valve seat on said front end wall of said valve casing inside thereof in encircling relation to said input member;
- a first annular valve member including an inner peripheral portion sealingly secured to said input member around the outer periphery thereof, an outer peripheral portion formed to serve as a valve closure element engageable with said first valve seat and an intermediate flexible web portion, said first valve seat and said first valve member cooperating with each other to define in said valve casing radially inner and outer spaces respectively communicating with said first and second power chambers;
- a second valve seat on the rear end face of said input member;
- a second valve member having an outer peripheral porting sealingly secured to said valve casing around the inner peripheral wall thereof, an inner peripheral portion adapted to serve as a valve closure element engageable with said second valve seat and an intermediate flexible web portion;
- an annular reinforcement member provided with a radial through hole therein and interconnecting said valve closure elements of said first and second valve members integrally with each other to define therebetween an axial distance smaller than that between said first and second valve seats when said input member is in its rearmost position;
- and
- spring means associated with said first and second valve closure elements to bias the two elements toward said respective valve seats.
Dependencies are inferred from the claim text.