Vacuum control apparatus for maintaining the operating condition of a vacuum responsive device during loss and resumption of power

摘要

A vacuum control apparatus (10) for generating and controlling the source of vacuum produced from a source of pressurized air (12) in communication with at least one vacuum responsive device (32) wherein the vacuum control apparatus maintains the operating conditions of the system during the loss and resumption of power. The vacuum control apparatus provides at least one venturi (26) for creating a vacuum through a flow of pressurized air. A first valve train (42) selectively provides a flow of pressurized air from a pressurized air source to the vacuum creating means. A second valve train (16) communicates with the pressurized air source to selectively provide a flow of pressurized air to the vacuum responsive device. A last function valve (50) communicates with the first and second valve trains and a pressurized air source to maintain the operating condition of the vacuum control apparatus during the loss and resumption of power to the first and second valve trains.