ELECTRIC ALARM DEVICE FOR INDICATING THE VARIATION OF A PHYSICAL QUANTITY IN A VEHICLE TIRE

• US 3,859,628 A
• Filed: 06/11/1973
• Issued: 01/07/1975
• Est. Priority Date: 06/16/1972
• Status: Expired due to Term

• Current Assignee: Pirelli Coordinamento Pneumatici SpA (Pirelli & C SPA)
• Original Assignee: Fiorenzo Favini
• Inventors: Favini, Fiorenzo
• Primary Examiner(s): Waring, Alvin H.
• Application Number:
  US05/368,998
• Time in Patent Office: 575 Days
• Field of Search: 340/58,52R 200/61.08,61.22,61.25
• US Class Current: 340/445
• CPC Class Codes: B60C 23/041 Means for supplying power to the signal- transmitting means on the wheel
• CPC Class Codes: B60C 23/043 using transformer type signal transducers, e.g. rotary transformers

Abstract

An apparatus is provided for monitoring a physical quantity in a pneumatic tire and for detecting variation in the physical quantity outside a preset limit which combines a battery having two electrodes and an electrolyte in a sealed outer casing, a detector means for detecting variation outside the preset acceptable limit and a means coupled to the detector means for opening the sealed casing when the variation is detected to thereby permit contact between the electrolyte and the electrodes to generate an output voltage and actuate an alarm.

Claims

1. Apparatus for monitoring a physical quantity in a pneumatic tire and foR providing an indication of a variation in said physical quantity outside a preset acceptable limit, said apparatus comprising:

a. a battery having two electrodes and an electrolyte contained in an outer casing, said electrolyte being contained in a sealed container within said outer casing;

b. detector means for monitoring said physical quantity and detecting said variation outside said preset acceptable limit; and

c. means coupled to said detector means to open said sealed casing when said variation is detected, thereby permitting contact between said electrolyte and said electrodes to generate a voltage output.

2. The apparatus according to claim 1, further comprising a pressure switch for monitoring the pressure in a pneumatic tire, said means permitting contact between said electrolyte and said electrodes to generate said voltage output when said pressure switch detects a pressure in said tire which is below said preset acceptable limit.

3. The apparatus according to claim 1, further comprising:

a pressure switch for monitoring the pressure in a pneumatic tire;

said supply means comprising a battery having two electrodes and an electrolyte, said electrolyte being maintained normally separated from said electrodes; and

means to bring said electrolyte and said electrodes into contact when said pressure switch detects a pressure in said tire which is below said preset acceptable limit.

4. The apparatus according to claim 3, wherein said electrodes and electrolyte are housed in a casing, said electrolyte is contained in a sealed container within said casing and said casing contains an absorbant material located between said two electrodes and a cushioning material located substantially around said sealed container.

5. The apparatus according to claim 3, further comprising a housing containing said supply means, said pressure switch and said means to bring said electrolyte and said electrodes into contact, said housing being mounted for rotation with said tire.

6. The apparatus according to claim 5, further comprising a circuit including an oscillator and a coil coupled to the output of said oscillator for transmitting an electromagnetic signal corresponding to the output oscillations of said oscillator, the input of said oscillator being connected to the output of said battery without the interposition of switchable mechanical contacts.

7. The apparatus according to claim 6, further comprising a pickup coil mounted on a stationary support relative to said tire for receiving signals transmitted by the coil coupled to said oscillator;

and means coupled to the output of said pickup coil for producing a warning signal when said variation from said preset acceptable limit is detected.