VEHICLE ANTI-SKID AND ANTI-SPIN SIGNAL AND CONTROL DEVICE

• US 3,668,629 A
• Filed: 03/22/1971
• Issued: 06/06/1972
• Est. Priority Date: 02/25/1969
• Status: Expired due to Term

• Current Assignee: Walter S. Pawl
• Original Assignee: Walter S. Pawl
• Inventors: Pawl, Walter S.
• Primary Examiner(s): Waring, Alvin H.
• Application Number:
  US05/126,601
• Time in Patent Office: 442 Days
• Field of Search: 340/52,53,71,262 188/68,180,181 303/21
• US Class Current: 340/453
• CPC Class Codes: B60T 8/171 Detecting parameters used in the regulation; Measuring values used in the regulation
• CPC Class Codes: B60T 8/4809 Traction control, stability control, using both the wheel brakes and other automatic braking systems
• CPC Class Codes: B60T 8/74 sensing a rate of change of velocity

Abstract

A means for detecting the point at which the braking wheel begins to skid or the driving wheel begins to spin, by using circumferential accelerometers mounted on the wheels to indicate the initiation of a skid or a spin by an inertial displacement of each of the accelerometer weights as it passes the bottom of its rotation as the wheel starts to decelerate or accelerate its rotation faster than the resulting deceleration or acceleration of the vehicle, or is actually locked while the vehicle is still in motion, or is spinning while the vehicle is motionless. This displacement is used to control the means for reducing the maximum brake pressure or the maximum power that may be applied, to a maximum that the instant conditions of load, tire and road characteristics will permit without causing skidding or spinning of the particular wheel on which the accelerometers are mounted. Thus, by having the maximum pressure that may be applied to the brakes on each wheel, separately and automatically limited in this manner to get the maximum braking without skidding, a safe stop can be made even under the most hazardous conditions, in the shortest distance possible. Likewise, by having the maximum power applied, automatically limited in the same manner, to get maximum acceleration, a fast spurt to the desired speed can be safely and most speedily accomplished, even under adverse road conditions.

Claims

1. An anti-skid and anti-spin control device including an indicator signal means comprising at least one accelerometer mounted circumferentially on a common radius, on each brake and drive wheel of a power driven vehicle having a brake pressure control for the brake wheels and a power control for the drive wheels, said accelerometers being responsive to any imbalance between the rotational and linear inertias of the corresponding wheel at its contact point with the road, indicating the start of a skid or a spin due to the application of excessive brake pressure or of excessive power respectively, a stationary switch for each of said wheels, mounted below the wheel axis closely adjacent the path of said accelerometers for actuation thereby in response to such imbalance of the corresponding wheel, and a signal in the driver'"'"''"'"'s vicinity and operated by said switch to indicate a skid or spin as soon as it is started, to assist the driver in immediately regaining static traction and promptly returning to the maximum brake pressure or power that will not cause another loss of static traction.

2. An anti-skid and anti-spin control device as defined in claim 1, said stationary switch being a magnetic switch, and said accelerometers each including a magnetic weight portion movable from its normally shielded position, in response to said imbalance into an effective non-shielded position to actuate said magnetic switch by a magnetic impulse across the gap between the moving accelerometer and the stationary switch, said signal being a flshing light, and said switches on all the brake and/or drive wheels being connected in parallel to said signal light.

3. An anti-skid and anti-spin control device comprising at least one accelerometer mounted circumferentially on a common radius, on each brake and drive wheel of a power driven vehicle having a brake pressure control for the brake wheels and a power control for the drive wheels, said accelerometers being responsive to any imbalance between the rotational and linear inertias of the corresponding wheel at its contact point with the road, indicating the start of a skid or a spin due to the application of excessive brake pressure or of excessive power respectively, a stationary switch for each of said wheels, mounted below the wheel axis closely adjacEnt the path of said accelerometers for actuation thereby in response to such imbalance of the corresponding wheel, and a brake pressure limiting control operating circuit connected to said switch and having means to instantly reduce said brake pressure sufficiently to regain static traction at said wheel and to immediately return said brake pressure limiting control as closely as possible to the previous maximum before the loss of static traction.

4. An anti-skid and anti-spin control device as defined in claim 3, and a signal in the driver'"'"''"'"'s vicinity included in said switch operated circuits to indicate said loss of static traction.

5. An anti-skid and anti-spin control device as defined in claim 4, all of said limiting control circuits being connected in parallel to a single signal indicating loss of static traction at any of said wheels.

6. An anti-skid and anti-spin control device as defined in claim 5, said signal being a flashing light.

7. An anti-skid and anti-spin control device comprising at least one accelerometer mounted circumferentially on a common radius, on each brake and drive wheel of a power driven vehicle having a brake pressure control for the brake wheels and a power control for the drive wheels, said accelerometers being responsive to any imbalance between the rotational and linear inertias of the corresponding wheel at its contact point with the road, indicating the start of a skid or spin due to the application of excessive brake pressure or of excessive power respectively, a stationary switch for each of said wheels, mounted below the wheel axis closely adjacent the path of said accelerometers for actuation thereby in response to such imbalance of the corresponding wheel, and a power limiting control actuated by a circuit operated by any of the switches for the drive wheels, said drive wheel switches being connected in parallel to said common power limiting control operating circuit, said limit control having means for instantly reducing the power applied sufficiently to restore static traction and promptly returning said power control as close as possible to the maximum applied just before losing static traction at said drive wheels.

8. An anti-skid and anti-spin control device as defined in claim 7, and a signal in the vicinity of the driver connected in said limiting control circuit.

9. An anti-skid and anti-spin control device as defined in claim 7, and a brake pressure limiting control circuit for each brake wheel circuit adapted for connection to the switches on the corresponding wheels, said limiting control having means for instantly reducing the brake pressure on said wheel to restore static traction, and for returning as close as possible to the maximum brake pressure previously applied just before losing static traction.

10. An anti-skid and anti-spin control device as defined in claim 9, and a skid signal in the vicinity of the driver connected to the brake pressure limiting control circuits, and a spin signal similarly located and connected to the power limiting control circuit.

11. An anti-skid and anti-spin control device as defined in claim 10, and a main control switch for selectively activatively activating either the brake pressure limiting control circuits or the power limiting control circuit, as desired.

12. An anti-skid and anti-spin control device as defined in claim 11, and a signal circuit connected directly to each brake wheel and drive wheel switch, said signal circuits having a common terminal contact in the main control switch in an additional position for selectively activating the signal circuits alone to aid the driver in manual adjustment of the brake pressure or power controls respectively to maintain skidless or spinless maximum deceleration or acceleration driving operations, in emergency stops or starts.

13. An anti-skid and anti-spin control device for vehicles having at least one brake wheel and one drive wheel, anD brake pressure control means and power control means for the respective wheel or wheels, comprising sensing means mounted circumferentially on each brake wheel and/or drive wheel responsive to any imbalance in either direction, between the rotational and linear inertias of the corresponding wheel at its road contact point, including accelerometers mounted on said wheels, switch means mounted on the vehicle below the wheel axis closely adjacent to the path of the accelerometers on the corresponding wheel, said switch means being actuated by said sensing means to close an operating circuit when such imbalance occurs, a signal connected to said operating circuit to indicate to the driver the loss of static traction, to assist him in manipulating the brake pressure control means or the power control means to restore and maintain the highest static traction possible under the instant road conditions in either forward or reverse drive.