AUTOMATIC PRESSURE WARNING DEVICE FOR PNEUMATIC UNITS

• US 3,593,268 A
• Filed: 12/17/1968
• Issued: 07/13/1971
• Est. Priority Date: 12/17/1968
• Status: Expired due to Term

• Current Assignee: John A. Arvan
• Original Assignee: John A. Arvan
• Inventors: Arvan, John A.
• Application Number:
  US04/760,257
• Time in Patent Office: 938 Days
• US Class Current: 340/442
• CPC Class Codes: B60C 23/0467 Electric contact means, e.g. slip-rings, rollers, brushes
• CPC Class Codes: B60C 23/0496 Valve stem attachments positioned outside of the tyre chamber

Abstract

An improved automatic warning device for tires to identify pressures outside of predetermined ranges. The device is secured to a standard valve stem. An opening in a plug allows the interior tire pressure to bear against a spring biased plunger. The biasing force of the spring is varied by adjustment of a screw member. The plunger rod bears against a spring biased conductor and in the normal state, the rod maintains the conductor out of electrical contact. If the pressure falls below a certain level the plunger rod withdraws away from the conductor, and the conductor is moved by its biasing means into electrical contact. If the pressure rises above a certain level, the plunger rod bears more strongly against the conductor, and the conductor is moved against its biasing means in the opposite direction and into electrical contact.

Claims

1. An improved automatic warning device for pneumatic units to identify pressures outside of a predetermined range comprising:

a. a housing secured to an outlet from the pneumatic unit providing the device from a signal at all times equivalent with the pressure within the unit;

b. plunger means within the housing responsive to the pressure within the pneumatic unit, the plunger means having a rod;

c. compression spring means urging said plunger toward the outlet;

d. adjustment means within the housing to vary the forces within the spring, said means being adjustably spaced from the plunger means and locating the compression spring therebetween; and

e. a closure cap assembly detachably secured to the housing;

f. contact means within the cap assembly, said means including a conducting cup and a second compression spring urging said cup toward the outlet, said cup being movable from a first contact position to a second contact position, the rod of the plunger means engaging the cup to move said cup from the first contact position to a median position without contact, and to the second contact position, depending on the pressure within the pneumatic unit.

2. The invention according to claim 1, wherein the conducting cup has a detent sized to receive the rod of the plunger means.

3. The invention according to claim 1, further including an insulating sleeve surrounding said cup and second spring, a second conducting cup telescoping over said sleeve and having a shoulder portion forming the first contact position, and a conducting washer abutting said second conducting cup and spaced from the shoulder portion thereof forming the second contact position.

4. The invention according to claim 1, wherein said adjustment means comprises a screw member having a seat in one end to receive the compression spring and a stem portion at the other end thereof, said screw member being located intermediate the plunger means and the closure cap assembly and having a through-opening therein, the rod of said plunger means passing through said opening.