Valve for levitated vehicle track

Claim 2

A valve device for use with an air levitated vehicle comprising a valve housing, a main passageway defined in said housing leading from a high pressure area to a low pressure area, a flexible diaphragm member having a first surface partially defining said passageway, said passageway further being defined by a surface portion of said valve housing facing said diaphragm member, and means to subject a second surface of said diaphragm member and opposite from the first surface to a fluid pressure greater than the pressure of said low pressure area to cause said diaphragm member to deflect against the surface portion of said valve housing facing said diaphragm member thereby to seal said passageway, pressure relief means open to the second surface of said diaphragm member responsive to a predetermined condition to permit the fluid pressure acting on the second surface to be relieved, thereby to cause the first surface of the diaphragm to move away from the surface portion defining said passageway, and permit fluid flow through said passageway and means responsive to presence of said air levitated vehicle adjacent said valve device to actuate said pressure relief means.

Claim 3

The combination as specified in claim 1 wherein said pressure relief means comprises a pilot diaphragm and a pressure relief passageway, a first portion of a first side of said pilot diaphragm sealing a portion of said pressure relief passageway in a normal pilot diaphragm position, means on an opposite side of said pilot diaphragm to control the level of pressure on said first side necessary to move said pilot diaphragm away from its normal position, a second portion of said pilot diaphragm being open to a second portion of said pressure relief passageway whereby when the pressure differential on said pilot diaphragm exceeds a preselected level said pilot diaphragm moves away from its normal position and said first and second portions of said pressure relief passageway are fluidly connected and fluid under pressure acting on the second side of the first mentioned diaphragm is discharged through said pressure relief passageway.

Claim 4

The combination as specified in claim 2 wherein said pilot diaphragm forms a portion of a control pressure chamber, a control pressure conduit fluidly open to said control pressure chamber, whereby the pressure level of fluid in said control pressure conduit determines the pressure in said second portion of said pressure relief passageway necessary to move the pilot diaphragm away from its normal position.

Claim 5

The combination as specified in claim 2 wherein said second portion of said pressure relief passageway opens to a region in which pressure rises when said levitated vehicle approaches said valve device, said pilot diaphragm being urged away from its normal position by the pressure rise in the second portion caused by the levitated vehicle.

Claim 6

The valve device of claim 1 wherein said pressure relief means includes a pressure relief passageway and a pilot diaphragm normally sealing said relief passageway and movable away from said relief passageway, said relief passageway being open to the second side of the first mentioned diaphragm and under pressure when said pilot diaphragm closes said relief passageway, said housing having surfaces surrounding said opening, said pilot diaphragm haviNg a chamber defined therein, a chamber opening aligned with said relief passageway and permitting pressure from the relief passageway to enter said chamber when the relief passageway is closed, said diaphragm having thin wall portions surrounding the chamber opening whereby pressure entering said chamber opening urges the thin wall portions against the surfaces surrounding said relief passageway when the pilot diaphragm closes the relief passageway.

Claim 7

The combination as specified in claim 1 wherein said pressure relief means comprises a pressure relief passageway, a pilot diaphragm sealing said pressure relief passageway in a normal pilot diaphragm position, and means to cause movement of said pilot diaphragm away from its normal position to open said pressure relief passageway in response to a signal indicating presence of a vehicle on said track adjacent said valve.

Claim 8

A valve device for use with an air levitated vehicle comprising a valve housing, a floor member over which said vehicle passes, said valve housing being fastened with respect to said floor member to control flow of fluid from a high pressure area below said floor member to a low pressure area above said floor member, a main passageway defined in said valve housing leading from said high pressure area to a location above said floor member, a flexible diaphragm member in said valve housing having a first surface partially defining said passageway, said passageway further being defined by a surface portion of the valve housing facing said diaphragm member, and means to subject a second surface of said diaphragm member opposite from the first surface to a fluid pressure greater than the pressure of said low pressure area to cause said diaphragm member to deflect against the surface portion of said valve housing facing said diaphragm member thereby to seal said passageway, pressure relief means open to the second surface of said diaphragm member responsive to a predetermined condition to permit the fluid pressure acting on the second surface of said diaphragm member to be relieved thereby to cause the first surface of said diaphragm member to move away from said surface portion defining said passageway, said pressure relief means comprising a pilot diaphragm and a pressure relief passageway, said pilot diaphragm sealing a portion of said pressure relief passageway leading to said first mentioned diaphragm member in a normal pilot diaphragm position, means on an opposite side of said pilot diaphragm to control the level of pressure on said first side necessary to move said pilot diaphragm away from its normal position, a second portion of said pilot diaphragm being open to a second portion of said pressure relief passageway, said second portion of said pressure relief passageway opening in a location to sense changes in pressure above said floor member adjacent said valve device.

Claim 9

A valve device for use with an air levitated vehicle comprising a valve housing, a floor member over which said vehicle passes, said valve housing being fastened with respect to said floor member to control flow of fluid from a high pressure area below said floor member to a low pressure area above said floor member, a main passageway defined in said valve housing leading from said high pressure area to a location above said floor member, a flexible diaphragm member in said valve housing having a first surface partially defining said passageway, said passageway further being defined by a surface portion of the valve housing facing said diaphragm member, and means to subject a second surface of said diaphragm member opposite from the first surface to a fluid pressure greater than the pressure of said low pressure area to cause said diaphragm member to deflect against the surface portion of said valve housing facing said diaphragm member thereby to seal said passageway, pressure relief means open to the second surface of said diaphragm member responsive to a predetermined condition to permit the fluid pressure acting on the second surface of said diaphragm member to be relieved thereby to cause the first surface of said diaphragm member to move away from said surface portion defining said passageway, said pressure relief means comprising a pilot diaphragm and a pressure relief passageway, said pilot diaphragm sealing a portion of said pressure relief passageway leading to said first mentioned diaphragm member in a normal pilot diaphragm position, means on an opposite side of said pilot diaphragm to control the level of pressure on said first side necessary to move said pilot diaphragm away from its normal position, a second portion of said pilot diaphragm being open to a second portion of said pressure relief passageway, said second portion of said pressure relief passageway opening in a location to sense changes in pressure above said floor member adjacent said valve device.

Claim 10

The combination as specified in claim 7 wherein said floor member has valve openings therethrough, and said valve device is a self contained unit fitting into one of said openings, and twist lock means to releasably retain said valve device in an opening in said floor member.

Claim 11

A track for propelling and levitating an air levitated vehicle, said track having a floor with an upper surface, said floor defining one wall of a first duct carrying fluid under pressure at a pressure higher than atmospheric pressure for levitating said vehicle, valve means positioned with respect to said floor for controlling fluid flow from said first duct to levitate said vehicle, twist lock means cooperating between said valve means and portions of said track whereby said valve means can be inserted and replaced by engaging or disengaging the twist lock means, means defining a separate duct in said first duct comprising a control pressure header means, port means in said control pressure header means for one valve means associated with said port means, resilient sealing means between said one valve means and said control pressure headeR means and surrounding the corresponding port means in said header means, said resilient sealing means forming at least a portion of a passageway between said port means and portions of a corresponding valve means is locked into position with said twist lock means.

Claim 12

A track for propelling and levitating an air levitated vehicle, said track having a floor with an upper surface, said floor defining one wall of a first duct carrying fluid under pressure at a pressure higher than atmospheric pressure for levitating said vehicle, valve means positioned with respect to said floor for controlling fluid flow from said first duct to levitate said vehicle, twist lock means cooperating between said valve means and portions of said track whereby said valve means can be inserted and replaced by engaging or disengaging the twist lock means, means defining a separate duct in said first duct comprising a control pressure header means, port means in said control pressure header means for one valve means associated with said port means, resilient sealing means between said one valve means and said control pressure headeR means and surrounding the corresponding port means in said header means, said resilient sealing means forming at least a portion of a passageway between said port means and portions of a corresponding valve means is locked into position with said twist lock means.