Low tire pressure warning device

• US 4,048,614 A
• Filed: 01/05/1977
• Issued: 09/13/1977
• Est. Priority Date: 08/18/1975
• Status: Expired due to Term

• Current Assignee: Harry J. Shumway
• Original Assignee: Harry J. Shumway
• Inventors: Shumway, Harry J.
• Primary Examiner(s): Waring, Alvin H.
• Application Number:
  US05/757,052
• Time in Patent Office: 251 Days
• Field of Search: 340/58, 340/224, 200/61.22, 200/61.25, 200/61.26
• US Class Current: 340/447
• CPC Class Codes: B60C 23/0408 transmitting the signals by non-mechanical means from the wheel or tyre to a vehicle body mounted receiver
• CPC Class Codes: B60C 23/0494 Valve stem attachments positioned inside the tyre chamber

Abstract

A pressure detector and radio transmitter component of a tire pressure warning system for a wheeled vehicle, with the component being associated with a tubeless vehicle tire by being mounted on the wheel rim on which the tire is mounted so that the component is wholly located in the sealed space formed by the interior of the tubeless tire and the wheel rim on which the tire is mounted.

Claims

1. A tire pressure alarm system for a vehicle having a wheel with a rim forming an annular well of a predetermined depth, said rim being adapted to receive a tire to form therewith an airtight chamber, said rim having an air inlet valve having a first end outside said airtight chamber and a second end inside said airtight chamber, said alarm system including an elongated operative component adapted to be removably connected to said second end and located entirely within said airtight chamber, so that the elongated direction of said operative component is substantially parallel to the axis of rotation of said wheel, said operative component including an air chamber adapted to receive air from said airtight chamber, said operative component further including an actuable radio transmitter and power source therefor situated within the air chamber, and a switch and diaphragm means, said switch being situated along said elongated direction so as to be substantially impervious to centrifugal force due to rotation of said wheel, said switch and diaphragm means being responsive to the air pressure in said air chamber to close said switch to actuate said transmitter when said air pressure is at a predetermined low pressure.

2. An operative component as defined in claim 1 in which said switch includes two parallel plates having faces situated perpendicular to said elongated direction.

3. An operative component as defined in claim 1 in which said power source, said transmitter, said switch and said diaphragm are positioned serially within said air chamber along the elongated direction.

4. An operative component as defined in claim 1 in which one side of said air chamber is easily removable to permit access to said power source, said transmitter, said switch and said diaphragm.

5. An operative component as defined in claim 1 further including means adjustable from outside said operative component for adjusting said predetermined low pressure.

6. An operative component as defined in claim 1 in which said operative component is connected to said second end by means of a screw thread.