Patent ID: 9596970
Date: 2017-03-21
CPC Classifications: A47L,B01D,G05D,Y10T

Claim:
1. A valve comprising: a pneumatically discrete housing having first and second ports with different cross-sectional areas; first and second plates shaped and sized to seal said first and second ports, respectively, against pneumatic flow; a shaft connecting said first and second ports in a configuration in which said ports cannot be simultaneously sealed; and an operating mechanism that alternates said shaft between a first orientation in which said first plate seals said first port and a second orientation in which said second plate seals said second port, said mechanism comprising a spring biasing said shaft to seal a smaller one of said ports in said first orientation, a tension of said spring being calibrated to allow said shaft to alternate in response to a threshold force applied intermittently thereto to said second orientation.