Four wheel drive vehicle with antilock brake device and associated method operation
First Claim
1. An antilock brake device for a four wheel drive vehicle having front and rear axles, left and right wheels on each axle with brakes associated with each wheel, a power unit drivingly connected to one of said axles, the other axle being coupled for drive together with said one axle, a hydraulic braking system for controlling the hydraulic pressure applied to the brakes, and antilock control means coupled to said braking system for controlling the hydraulic braking pressure to reduce the pressure when a wheel is about to be locked, said antilock control means comprising a front wheel control section for controlling the brakes of the front wheels and a rear wheel control section for controlling the brakes of the rear wheels, and means included in said front and rear wheel control sections for keeping the hydraulic braking pressure reduced up to the completion of a braking operation, when any of the wheels is about to be locked.
1 Assignment
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Accused Products
Abstract
An antilock brake method and device for a four wheel drive vehicle having front and rear axles, left and right wheels on each axle with brakes associated with each wheel, a power unit drivingly connected to one of the axles, the other axle being coupled for drive together with the driven axle, a hydraulic braking system for controlling the hydraulic pressure applied to the brakes, and an antilock control system coupled to the braking system for controlling the hydraulic braking pressure to reduce the brake pressure when a wheel is about to be locked. The antilock control system includes a front wheel control section for controlling the brakes of the front wheels, a rear wheel control section for controlling the brakes of the rear wheels, and circuit elements included in the front and rear wheel control sections for keeping the hyraulic braking pressure reduced up to the completion of a braking operation, when any of the wheels is about to be locked. In a particular embodiment the rear wheel control section reduces the braking pressure in the rear wheel brakes and maintains the pressure reduced during a braking operation when any of the wheels is about to be locked.
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Citations
18 Claims
- 1. An antilock brake device for a four wheel drive vehicle having front and rear axles, left and right wheels on each axle with brakes associated with each wheel, a power unit drivingly connected to one of said axles, the other axle being coupled for drive together with said one axle, a hydraulic braking system for controlling the hydraulic pressure applied to the brakes, and antilock control means coupled to said braking system for controlling the hydraulic braking pressure to reduce the pressure when a wheel is about to be locked, said antilock control means comprising a front wheel control section for controlling the brakes of the front wheels and a rear wheel control section for controlling the brakes of the rear wheels, and means included in said front and rear wheel control sections for keeping the hydraulic braking pressure reduced up to the completion of a braking operation, when any of the wheels is about to be locked.
- 11. A method of controlling a hydraulic braking pressure supplied to brakes of a four wheel drive vehicle having left and right wheels on front and rear axles which are driven from a power unit, said method comprising sensing conditions at each wheel during braking to detect when one of said wheels is about to become locked, reducing the braking pressure to both brakes on one of said axles in response to detection that one of the wheels is about to be locked and maintaining the reduction of the braking pressure on both brakes on said one axle during the entire period of braking.
Specification