Tire pressure warning system

• US 4,067,376 A
• Filed: 01/16/1976
• Issued: 01/10/1978
• Est. Priority Date: 12/04/1973
• Status: Expired due to Term

• Current Assignee: Safety Research & Engineering Associates
• Original Assignee: Safety Research & Engineering Corporation
• Inventors: Barabino, William A.
• Primary Examiner(s): Hoffman, Drayton E.
• Assistant Examiner(s): Silverberg, Fred A.
• Application Number:
  US05/649,846
• Time in Patent Office: 725 Days
• Field of Search: 152/415, 152/418, 340/58, 137/223, 137/226, 116/34 R, 116/114 PV, 116/DIG. 16
• US Class Current: 152/418
• CPC Class Codes: B60C 23/004 the control being done on the wheel, e.g. using a wheel-mounted reservoir
• CPC Class Codes: B60C 23/0403 Mechanically generated audible signals, e.g. by buzzer or whistle signals
• CPC Class Codes: B60C 23/0469 Transmission by sound, e.g. ultra-sound
• CPC Class Codes: F16K 15/20 specially designed for inflatable bodies, e.g. tyres connecting valves to inflatable bodies B60C29/00

Abstract

Excessively high or low tire pressure is detected automatically with a warning signal generated for the operator. A device is attached to each wheel and includes a spring-loaded piston mounted for reciprocation in a cylinder formed in the device. The cylinder is provided with a porting arrangement which opens only at certain pressure limits. When the ports are opened a sonic or ultrasonic signal is generated and detected by sensors located in proximity to each wheel. The signals detected by the sensors are processed and utilized to actuate a warning signal that provides a visual and/or audio output for the operator. Means are provided for discriminating between background noise and the generated signal as well as to discriminate as to the location of the affected tire. In a modification of the invention, a reserve chamber is integrated into the body of the wheel and is adapted to replenish automatically air lost from the tire.

Claims

1. An automatic air replenishment and low pressure warning system for a pneumatic tire, comprising

a. a wheel adapted to support a tire mounted thereto,

2. b. said wheel being formed with spaced tire supporting front and rear walls joined at their inner portions and an annular wall between said front and rear walls defining an integral annular concentric chamber adapted to store a quantity of compressed air at a pressure higher than the normal pressure in said tire,

c. normally closed pressure responsive valve means connecting said chamber to the interior of said tire and adapted to open when the pressure in said tire drops to a predetermined level whereby replenishing pressurized air is delivered into said tire,

d. said valve means including a release valve fixed to said annular wall and formed with a cylindrical chamber therein, a spring loaded rod movably mounted in said chamber and adapted to open and close said chamber according to the pressure in said tire,

e. said valve means formed with a passageway and including an acoustical signal generating device operatively connected to said rod through said passageway and adapted to produce an acoustical warning signal in the event of a low pressure condition in said tire, and,

f. acoustic sensing means disposed remotely from said tire and responsive to an acoustic signal generated thereby, said sensing means including warning means actuated by said sensing means upon sensing of an acoustic signal.