PRESSURE INDICATING DEVICES

摘要

A pressure indicating device (2), e.g. for securing to a tyre valve (1) is disclosed. It contains a flexible impermeable diaphragm (7) on one wall of a permanently hermetically sealed chamber (8) pressurised to a given pressure. A mechanical linkage (10, 12) which moves depending on whether the pressure, e.g. in a tyre to which the device is attached, is greater or less than that in its chamber (8), e.g. rotates a bicoloured ball (14), so that the colour displayed provides a visual signal that indicates if the tyre pressure is above or below the given pressure. This enables a puncture or air loss to be detected by a rapid glance.