SELF-LAPPING TYPE CONTROL VALVE DEVICE

摘要

The self-lapping type control valve has a check valve provided by a seal at the interface of the control piston diaphragm and a recess in which the diaphragm is connected to the valve body. The seal is effective to isolate a control chamber on one side of the control piston from a constant pressure chamber on the opposite side when the control piston is actuated in response to a reduction in the control chamber fluid pressure to initiate a brake application. This seal is displaced from a ridge at the opening of the recess with which the diaphragm is also engageable when actuation of the control piston occurs in response to a relatively large reduction of the control chamber pressure.