초록 ▼

A vacuum check valve comprising a single umbrella valve responding to vacuum differences between the input and output of the check valve. The check valve directs the output line to feed a vacuum operated device with either the vacuum source or reference air through a bleed passage. The umbrella shap

A vacuum check valve comprising a single umbrella valve responding to vacuum differences between the input and output of the check valve. The check valve directs the output line to feed a vacuum operated device with either the vacuum source or reference air through a bleed passage. The umbrella shaped valve eliminates the requirement for a diaphragm operated poppet valve.

대표청구항 ▼

A vacuum check valve for use in a vacuum operated system for preventing the flow of air contaminates and vapors from a vacuum source to vacuum operated devices, the check valve comprising: a housing with a first and second chamber therein; an orifice interconnecting said first and second chamber; an

A vacuum check valve for use in a vacuum operated system for preventing the flow of air contaminates and vapors from a vacuum source to vacuum operated devices, the check valve comprising: a housing with a first and second chamber therein; an orifice interconnecting said first and second chamber; an input port connected to said first chamber and adapted to receive the vacuum source; an output port from said first chamber and adapted to be connected to the vacuum operated devices, said output port spaced from said input port; a reference pressure source input connected to said second chamber; a unitary umbrella valve in said orifice having an umbrella-shaped top surface overlying both said orifice and said output port, an elongated stem axially aligned from the underside of said umbrella-shaped top surface and extending through said orifice and into said second chamber; an orifice closing member positioned on said stem and spaced from said umbrella-shaped top surface and being operable when the vacuum at said output port is equal to or less than the vacuum at said input port for closing said orifice from said reference pressure source allowing the flow of air only from said output port to said input port, and a circular member connected on the underside of said umbrella-shaped top surface for sealing said orifice only when the vacuum at said output port is greater than the vacuum at said input port; and at least one bleed passage under said circular member and extending from said orifice for allowing the flow of air only between said output port and said reference pressure source input when the vacuum at said output port is greater than the vacuum at said input port.