| 摘要 |
<p>This invention describes a pressure gauge which in one embodiment is adapted to be continuously mounted on the valve stem of the inflated device, thereby providing a continuous indication of the pressure therein It includes an airtight enclosure formed by an expandable means such as a diaphragm, positioned within an outer housing The gauge is adapted to contact the standard valve stem in the inflated device to release pressurized gas from the device into the airtight enclosure In response thereto, the airtight enclosure expands Cooperating with this expansion of the airtight enclosure is a piston like member which includes means for controlling the expansion of the airtight enclosure The control means is calibrated so that the piston like member moves an axial distance in an amount proportional to the pressure of the gas in the tube The piston has an indicator band painted thereon which positions itself opposite appropriate psi markings on the outside of the housing This provides a ready indication of the pressure The means for releasing the pressure into the expandable, airtight enclosure is further adapted to enable additional pressurized gas to be introduced into the inflated device The expandable enclosure is adapted to insure an airtight seal within the gauge if the diaphragm should rupture for any reason. Other embodiments of the basic invention describe alternate approaches to providing the expandable airtight enclosure including expandable bellows, a hollow flexible tube or a scheme wherein the space between the piston member and the outer housing is sealed by suitably positioned O-rings. Still other embodiments describe a passive gauge which must be depressed by the operator's thumb to function but which also provide means for supplying pressurized gas to the inflatable device while the gauge is in place. These embodiments provide a doubling back of the airtight enclosure reducing the overall height of the gauge.</p> |
