| 摘要 |
<p>The disclosure describes a valve cap which indicates the pressure within a pneumatic tire. The valve cap comprises a sleeve which may be mounted on the valve tube of the pneumatic tire and which includes an actuating member for opening a valve within the valve tube when the sleeve is mounted on the valve tube; a compressed-air chamber within the sleeve which communicates with the interior of the tire through the open valve and which includes a movable wall structure, such as a diaphragm or a piston, that seals the compressed-air chamber relative to ambient pressure and that moves in a first axial direction in response to an increase in pressure in the compressed-air chamber; an indicator mounted for axial movement within the sleeve and actuated by the diaphragm or piston; a marking member cooperatively arranged with the indicator for movement in the first axial direction through the sleeve; a return movement inhibitor associated with the marking member for inhibiting movement of the marking member; and a spring cooperating with the indicator and biased toward the opposite axial direction whereby an increase in pressure in the compressed-air chamber axially moves the indicator and marking member in the first axial direction relative to the sleeve and a decrease in the compressed-air chamber axially moves the indicator in the opposite axial direction relative to the sleeve while the return movement inhibitor retains the marking member in its position relative to the sleeve.</p> |
