Abstract: A low pressure tire indicator is a mechanical device for producing an audible warning to the driver of low or inadequate tire pressure. The low pressure tire indicator includes a strap for mounting the low pressure tire indicator to a wheel hub. A spring housing is mounted on the strap. A rocker arm is mounted on an anchor pin positioned within the spring housing, and extends away from the wheel hub towards the inside tread wall of a pneumatic tire mounted on the wheel hub. The rocker arm includes a roller on a free end for engaging the inside tread wall of the tire during a low pressure condition. A hammer is mounted on the anchor pin and moves in unison with the rocker arm. A spring is mounted on the anchor pin, and, during proper tire inflation, normally urges the hammer into contact with the wheel hub, and normally positions the roller on the free end of the rocker arm between the wheel hub and the inside tread wall of the tire.

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: A pneumatic run-flat insert for a pneumatic tire is provided with circumferential sections having different radii. During vehicle operation in a run-flat condition the different insert radii cause a vibratory disturbance at a wheel axle that alerts the driver of the existence of a run-flat condition or an abnormally low-pressure condition in the tire. During normal driving conditions there is clearance between the insert and the tire liner and no warning vibrations will occur in the wheel axle.In various embodiments of the invention the different insert radii correspond to two or more ply sections in an insert ply having different cord angles. A relatively high cord angle ply section will furnish a relatively larger radius than the ply section with a relatively low cord angle.

Abstract: This invention is concerned with a tire pressure drop audible warning-giving apparatus, which is provided in an air chamber defined by a pneumatic tire and a wheel rim assembled with the pneumatic tire so as to strike the wheel rim for emitting an alarming sound when a tire inner pressure is dropped in the air chamber below an allowable limit. The apparatus comprises in combination: a securing member secured to the wheel rim; a blow hammer provided spacedly from the securing member in the direction perpendicular to the radial direction of the wheel rim; and a connecting member made of a resilient material and having one end connected with the radially outer end of the securing member and the other end connected with the blow hammer; wherein the blow hammer has at its radially outer end a protrusion extending radially outwardly from the radially outer end of the connecting member, and at its radially inner end a blow portion.

Abstract: Tire deflation warning device comprising means for producing a noise which will not be suppressed by the vehicle suspension and will give a warning to the vehicle driver of the tire deflation.

Abstract: A tire pressure variation detector is fixed in the wall of the wheel rim and is adapted to signal whether the inner tube of the tire is inflated to the normal air pressure and also to signal whether the space outside the inner tube contains air under pressure which has escaped from the inner tube.