Abstract: A device for indicating a pressure drop or low pressure condition in a tire detects a pressure drop and makes an acoustic signal in response to the detection of the pressure drop. The device can include a strut for intermittently contacting a wall of a tire, a striker attached to the strut for striking the wheel rim, and a pressure-activated latch for preventing the strut from contacting the wall or the tire when the pressure in the tire is above a predetermined value by holding the strut tangent to the wheel rim.

Abstract: The low inflation warning device is a mechanical sound generating apparatus designated for attachment to a wheel assembly such that the apparatus is contained within the pneumatic space formed by the tire and rim. Whenever a condition of low pressure or overload exists on the wheel assembly a warning signal is generated. The signal is initiated by contact of the interior surface of the tire casing with the apparatus. The contact causes a portion of the apparatus to strike an anvil with sufficient force to generate an audible sound. The apparatus is self-setting under the influence of centrifugal force and will generate a warning of insufficient tire pressure or excessive tire load. The apparatus will generate a signal with each revolution of the wheel assembly to which it is mounted. Under extreme low inflation conditions the apparatus will continue to generate periodic warnings without damage to the tire.

Abstract: An improved catalytic gas generator, of the type used, for example, in a monopropellant hydrazine rocket engine includes a dynamic catalyst bed retention device. The dynamic retention device comprises a compression band surrounding a generally cylindrical catalyst bed that is axially restrained at both ends. A torsional force is applied to the compression band, which converts the torsional force into a radially inwardly directed compression force. As voids develop in the catalyst bed upon repeated impulsing, the inwardly directed compressive force redistributes the catalyst bed so as to fill the voids. The retention device thus allows the catalyst bed to perform at peak efficiency yielding a gas generator that can be repeatedly pulsed with uniformly reproducible results.