VEHICLE TIRE PRESSURE INDICATING AND SIGNALLING DEVICE

• US 3,697,944 A
• Filed: 12/09/1969
• Issued: 10/10/1972
• Est. Priority Date: 12/13/1968
• Status: Expired due to Term

• Current Assignee: Jisaku Murano
• Original Assignee: Jisaku Murano
• Inventors: Murano, Jisaku
• Primary Examiner(s): Waring, Alvin H.
• Application Number:
  US04/883,514
• Time in Patent Office: 1,036 Days
• Field of Search: 340/58,224 325/117 200/61.22,61.25 338/37 73/146.4,146.6
• US Class Current: 340/447
• CPC Class Codes: B60C 23/0433 Radio signals

Abstract

A tire pressure indicating and signaling device includes a pair of interconnected cylindrical elements, one of which is designed to be screwed directly on to the valve stem of a pneumatic tire and to mount a tire valve communicating with the chamber in this element. The other element encloses variable resistance means and electric contact means which are operative responsive to the pressure in the chamber of the valve stem mounted cylindrical element. The variable resistance means may comprise an iron powder element, a carbon element, or a pressure-sensitive transistor. A signal transmitter is connected to the variable resistance and to the contact means and may be mounted either directly on the tire or adjacent the tire on a fixed portion of the vehicle, such as an axle. When the transmitter is mounted on the tire, it transmits a radio signal to a receiver in the operator'"'"''"'"'compartment, and this receiver is connected to indicating and alarm means. When the transmitter is mounted on the fixed part of the vehicle, it is connected by conductors to the alarm and indicating means in the driver'"'"''"'"'s compartment.

Claims

1. In a device for indicating the air pressure in a tire on a movable vehicle, of the type including a pressure-responsive transducer rotatable with the tire and subjected to the tire internal pressure, operable to convert pressure variations into electrical value variations, a pressure indicating means on the vehicle body, and transmission means operable to transmit the electrical value variations to the indicating means, the improvement comprising, in combination, a first cylindrical body defining an air chamber having an open end, arranged to be threaded coaxially on the tire valve stem, and having a port therein communicating with said air chamber and the valve stem interior;

a tire inflating valve extending through a wall of said first body and communicating with said first air chamber and the valve stem interior;

a second cylindrical body secured in coaxial sealing relation to said first body and having wall means closing said air chamber;

a transducer, operable to convert pressure variations into electrical value variations, mounted within said second body and having a pressure-responsive portion included in said wall means and subjected to the pressure in said air chamber;

a signal transmitting unit;

means electrically connecting said unit to said transducer;

said transmitting means transmitting signals from said signal transmitting unit to said indicating means; and

a sealing enclosure completely covering the exposed surfaces of said second cylindrical body and its juncture with said first cylindrical body, and sealingly engaged with said first cylindrical body.

2. In a device for indicating the air pressure in a tire, the improvement claimed in claim 1, in which said sealing enclosure has a flexible outer end;

and a push element within said second cylindrical body adjacent said flexible outer end and operable, by depression of said flexible outer end, to check said signal transmitting unit.

3. In a device for indicating the air pressure in a tire, the improvement claimed in claim 1, in which said transducer comprises a pressure-sensitive transistor mounted in said wall means and exposed to the pressure in said air chamber, and an amplifier in said second body having its input connected to the output of said transistor.