Automatic tire pressure control

• US 3,927,708 A
• Filed: 01/28/1974
• Issued: 12/23/1975
• Est. Priority Date: 01/28/1974
• Status: Expired due to Term

• Current Assignee: Clement E. Hulme
• Original Assignee: Clement E. Hulme
• Inventors: Hulme, Clement E.
• Primary Examiner(s): Hoffman, Drayton E.
• Application Number:
  US05/437,065
• Time in Patent Office: 694 Days
• Field of Search: 152/415,418-422
• US Class Current: 152/418
• CPC Class Codes: B60C 23/127 the pumps being mounted on the hubs

Abstract

An air compressor apparatus for maintaining pressure in the tires of an automotive vehicle, the compressor being driven by wheel rotation as an incident to vehicular travel. The compressor rides in an upright position on a crank shaft which is connected to the vehicle axle for rotation therewith. Air compressed in the compressor cylinder is directed to an unloader valve settable to the desired tire pressure and effective to release compressed air to the atmosphere when the tire pressure is above a preset value. A conduit connects the unloader valve to the stem valve of the vehicle tire and has a rotary connector disposed intermediate its length to prevent twisting of the conduit as the tire rotates about the stationary compressor.

Claims

1. Air compressor apparatus for maintaining pressure in the tire of an automotive vehicle and comprising:

a crankshaft to be connected to the vehicle axle to rotate therewith;

air compressor cylinder means having a piston connected to said crankshaft, said cylinder means comprising primary and secondary cylinders, a filter for supplying atmospheric air to the primary cylinder, and a first conduit between the output of the primary cylinder and the input of the secondary cylinder;

a housing encompassing said crankshaft and having bearing means for rotatably supporting said crank shaft;

an unloader valve settable to the desired tire pressure and effective to release compressed air to the atmosphere when the tire pressure is above a preset value;

a second conduit connecting the output of the secondary cylinder to the unloader valve to supply air under pressure to the unloader valve;

a third conduit for connecting the unloader valve to the stem valve of a tire to be inflated; and

a rotary connector interposed in the third conduit.

2. Air compressor apparatus for maintaining pressure in the tire of an automotive vehicle and comprising:

a crankshaft to be connected to the vehicle axle to rotate therewith, said connection comprising a plate to be rigidly affixed to the end of said crankshaft normal to the axis thereof, said plate being disengagably mountable for rotation with a vehicle wheel, with the axis of said crank shaft aligned with the axis of the vehicle axle;

air compressor cylinder means having a piston connected to said crank shaft;

a housing encompassing said crank shaft and having bearing means for rotatably supporting said crank shaft;

an unloader valve settable to the desired tire pressure and effective to release compressed air to the atmosphere when the tire pressure is above a preset value;

a conduit connecting the pressure chamber of said cylinder means to said unloader valve to supply air under pressure to the unloader valve;

conduit means for connecting the unloader valve to the stem valve of a tire to be inflated; and

a rotary connector interposed in said conduit means.

3. Air compressor apparatus according to claim 2 having a counterweight for maintaining the compressor in generally an upright position when the vehicle axle it is to be secured to rotates incident to vehicular motion.

4. Air compressor apparatus according to claim 2 further characterized in that said rotary connector comprises a short cylindrical shaft having an internal passage therein, an annular chamber rotatably mounted thereon, said annular chamber communicating with the passage through an opening in the shaft, and ports in the shaft and annular chamber for connection to said conduit means, the cylindrical shaft being mounted on the outer surface of said housing in line with the axis of said crank shaft.

5. Air compressor apparatus for maintaining pressure in the tire of an automotive vehicle and comprising:

a crankshaft adapted to be ridigly mounted at the end of a vehicle axle in axial alignment with the vehicle axle for rotation therewith;

bearing means rotatably disposed along the crankshaft;

a housing encompassing the crankshaft and supported by the bearing means;

an air compressor cylinder mounted on the housing having a piston reciprocative therein, and driven by said crankshaft, an inlet valve for receiving atmospheric air, and an outlet valve through which compressed air is passed from the cylinder;

an oil sump formed in the lower portion of the housing adopted to contain fluid for lubricating the bearing means, crankshaft and piston of the compressor;

an unloader valve settable to the desired tire pressure and effective to release compressed air to the atmospherE when the tire pressure is above a preset value;

a first conduit connecting the outlet valve of the compressor cylinder to the unloader valve for supplying compressed air thereto;

a second conduit connecting the unloader valve to the stem valve of a tire which is to be maintained at proper pressure;

a rotary connector interposed in said second conduit to prevent twisting of said conduit as the vehicle wheel rotates; and

a counterweight for maintaining the compressor in a generally upright position when the crank shaft and vehicle axle rotate incident to vehicular motion.

6. Air compressor apparatus according to claim 5, further characterized in that said rotary connector comprises a short cylindrical shaft having an internal passage therein, an annular chamber rotatably mounted thereon and communicating with said passage through an opening in the shaft, and ports in the shaft and annular chamber for connection to the first and second conduits, the cylindrical shaft being mounted on the outer surface of the housing in axial alignment with the crank shaft.