High-low tire pressure signal switch

• US 3,961,309 A
• Filed: 06/18/1975
• Issued: 06/01/1976
• Est. Priority Date: 04/14/1975
• Status: Expired due to Term

• Current Assignee: Dyneer Corp. (Titan International Incorporated)
• Original Assignee: Aspro, Inc.
• Inventors: Eddy, William C.
• Primary Examiner(s): Waring, Alvin H.
• Application Number:
  US05/587,994
• Time in Patent Office: 349 Days
• Field of Search: 340/52 R, 340/58, 340/238, 200/61.22, 200/61.25, 116/34
• US Class Current: 340/448
• CPC Class Codes: B60C 23/043 using transformer type signal transducers, e.g. rotary transformers
• CPC Class Codes: B60C 23/0498 for rim attachments B60C23/0494, B60C23/0496 take precedence

Abstract

An air pressure-controlled electrical switch responsive to a change of pressure either above or below a predetermined desired pressure in a vehicle tire, to actuate a magnetically activated system for signaling such tire pressure change. The switch has piston means subject to one end to air pressure in a tire. The piston means is movable from an intermediate position where it normally is maintained by spring pressure and an opposed force imparted by the predetermined desired internal tire pressure which act i opposition on the piston means. The switch is actuated by movement of the piston means in one direction or the other from the intermediate position. The switch is normally closed when the piston means is in the intermediate position. The switch opens when the piston moves in one direction or the other from the intermediate position upon increase or reduction of the tire pressure from the predetermined desired value. The switch is connected electrically with a magnetically activated electronic signaling system.

Claims

1. In a vehicle tire pressure signaling system of a type in which magnetically activated alarm circuitry is actuated by a pressure switch, the construction including pressure cylinder means having pressure and contactor ends;

rod and O-ring piston means having pressure and switch contactor ends movable in said cylinder means;

spring means in the cylinder means reacting between the cylinder and piston means normally biasing the piston means toward the cylinder means pressure end to maintain the piston means in an intermediate position when the pressure ends of the piston and cylinder means are exposed to predetermined desired tire pressure;

the cylinder means contactor end having electrical contactors;

the piston rod contactor end having contactor means adapted to engage the cylinder means contactors in switch closed position when the piston means is in intermediate position to provide a circuit through the piston rod;

the piston means being movable in the cylinder means in one direction or the other from intermediate position upon change in tire pressure to above or below the said predetermined desired value to establish an open switch condition of the switch contactors and to open the circuit through the piston rod; and

means connecting said switch contactors with magnetically activated signaling system circuitry.

2. The construction defined in claim 1 in which the cylinder means is provided with means adapted to extend through a tire rim for mounting the cylinder on the tire rim with the pressure ends of the cylinder and piston means communicating with the interior of a rim-mounted vehicle tire to subject the pressure end of the piston means to tire pressure.

3. The construction defined in claim 1 in which insulating material plug means closes the contactor end of the cylinder means, in which the cylinder contactors are mounted on the plug means in spaced relation;

and in which electric conductors connected with the contactors are embedded in the plug means.

4. The construction defined in claim 3 in which the spring means reacts between the plug means and piston means.

5. The construction defined in claim 1 in which the piston rod has spaced annular contactor portions connected through the rod at the rod contactor end;

in which the cylinder means contactor end is formed with spaced commutator rings insulated from each other and adapted respectively to contact the piston rod contactor portions when the piston means is in intermediate position.

6. The construction defined in claim 5 in which the spaced piston rod contactor portions are separated by a reduced neck between the contactor portions.

7. The construction defined in claim 5 in which the spaced piston rod contactor portions are separated by an insulator ring.

8. The construction defined in claim 5 in which the piston means has a piston head at its pressure end carrying the O-ring movable in the cylinder means;

in which the piston rod projects to the rod contactor end from the head;

in which insulating material plug means closes the contactor end of the cylinder means;

in which the spaced commutator rings are carried by said plug means; and

in which the spring means reacts between the plug means and piston head.

9. The construction defined in claim 8 in which the spaced piston rod contactor portions are separated by a reduced neck between the contactor portions.

10. The construction defined in claim 8 in which the spaced piston rod contactor portions are separated by an insulator ring.

11. The construction defined in claim 8 in which the plug means is formed with an internal bore;

in which the piston rod contactor end projects into the bore; and

in which the spaced commutator rings are located in the bore adjacent the piston rod contactor end.

12. The construction defined in claim 8 in which the plug means is formed with a T-shaped head;

and in which a transmitter reed switch and inductor coil means are located in said T-head electrically connected by conductor means embedded in the T-head with the commutator rings.

13. The construction defined in claim 12 in which the plug means also is formed with an internal bore;

in which the piston rod contactor end projects into the bore; and

in which the spaced commutator rings are located in the bore adjacent the piston rod contactor end.

14. The construction defined in claim 2 in which the means for mounting the cylinder on a tire rim includes a hollow threaded stem on the cylinder means having an open end communicating with the cylinder, nut and lock washer means for clamping the stem to a tire rim, and filter means covering the open end of the stem.