The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 26, 1977
Filed:
Apr. 05, 1976
Herbert C Ovshinsky, Oak Park, MI (US);
Other;
Abstract
The selective drive unit performs the function of dual tandem rear differential drive on heavy duty trucks. The drive unit is employed between the tires on the wheels on the driven axle and those on the dead axle. The drive embodies a rotatable axle mounted on the chassis frame or suspended from the two axles with a pneumatic tire fixed on each end of the axle. The inflatable tires are disposed between a set of tires on the driven and dead axle, preferably on or near the centerline therebetween. The drive tires are preferably expandable and simultaneously or selectively inflated to engage the tires on the driven and dead axle on one or both sides of the truck. The inner tires of the pair located on both sides of the chassis frame are engaged by the expandable tires which may have an extending thread which engages the recesses of a matching tread on the truck tires. This provides a positive non-slip drive between the driven tires and those on the dead axle. The air in the inflatable tires is controlled by the driver from within the cab using the air provided on the truck for operating the brake thereof. The air causes the tires to be pressurized and preferably to be expanded so as to have a substantially flat area of engagement with the tires on the truck. The inflatable tires have the soft rubber surface thereof project within the recessess in the truck tires or, as pointed out above, may have a projecting tread which will mate with the openings in the tire tread to provide a locking engagement which reduces slippage and provides positive and frictionless torque transmission when both of the tires are pressurized. When both of the inflatable tires fixed to the rotatable shaft are pressurized the free wheeling effect of the driven differential is locked and torque from the truck motor is distributed to all eight tires simultaneously. When it is hazardous to lock up all of the eight wheels, only one of the inflatable tires need be pressurized to thereby provide a drive for all of the four tires on one side of the truck.