MERCURY SWITCH BRAKING SYSTEM

• US 3,861,489 A
• Filed: 07/05/1972
• Issued: 01/21/1975
• Est. Priority Date: 07/05/1972
• Status: Expired due to Term

• Current Assignee: Joseph A. Lang, Kenneth G. Lang, Robert L. Davis, Thomas J Lang
• Original Assignee: Joseph A. Lang, Kenneth G. Lang, Robert L. Davis, Thomas J Lang
• Inventors: Lang, Thomas J., Lang, Joseph A., Lang, Kenneth G., Davis, Robert L.
• Primary Examiner(s): Blix, Trygve M.
• Assistant Examiner(s): Kunin, Stephen G.
• Application Number:
  US05/269,034
• Time in Patent Office: 930 Days
• Field of Search: 180/103-104 188/112,181A,3R 280/112,432 303/7,20,21CG,24
• US Class Current: 188/112.00A
• CPC Class Codes: B60Q 1/305 Indicating devices for towed vehicles
• CPC Class Codes: B60T 11/107 overrun brakes with fluid means
• CPC Class Codes: B60T 17/22 Devices for monitoring or checking brake systems; Signal devices
• CPC Class Codes: B62D 53/0871 with stabilising means, e.g. to prevent jack-knifing, pitching, rolling, buck jumping stabilising in general B62D37/00; tractors B62D49/08

Abstract

A system is disclosed for sensing the lateral acceleration (centrifugal force) on an automobile which is towing a trailer and automatically applying the brakes of the trailer to prevent the lateral acceleration on the trailer from increasing to the point where the automobile would lose operative control of the trailer. The system consists of a pair of mercury switches which are interconnected to the braking system of the trailer. The mercury switches are placed at opposing variable inclined angles so that one switch senses lateral acceleration in the righthand direction and the other senses lateral acceleration in the lefthand direction. An indicating device which is interconnected into the system is located on the dashboard of a vehicle. The device indicates whether the sensing system is sensing lateral acceleration and whether the brakes are being applied.

Claims

1. An automatic stability control system for a vehicle to prevent swerving and swaying of said vehicle, said system comprising means for sensing lateral acceleration forces acting upon said vehicle to provide electrical acceleration signals representative of said forces, and brake means associated with said vehicle and responsive to said acceleration signals to actuate said brake means to prevent swaying and swerving of said vehicle, said sensing means including sensitivity adjustment means for setting the minimum magnitude of lateral acceleration force to which said sensing means responds to provide said acceleration signals, said sensing means including a pair of inclined mercury switch assemblies oriented to sense left and right lateral acceleration, said adjustment means including manually actuated means to vary the angle of inclination of the mercury switch assemblies, said switch assemblies including means indicating lateral acceleration approaching an unstable condition prior to the actuation of the brake means, each of said mercury switch assemblies including a pair of longitudinally spaced contacts in a container oriented in inclined position, a third contact extending longitudinally in the container in spaced relation to the pair of contacts, a quantity of conductive mercury in the container normally closing a circuit between the third contact and the lowest of the pair of contacts, said quantity of mercury being movable by lateral acceleration initially into a position for closing a circuit between the third contact and both of the pair of contacts to provide means for indicating lateral acceleration approaching an unstable condition and subsequently to a position closing a circuit between the third contact and the second contact of the pair of contacts located at the upper end of the container for applying the brake means when the lateral acceleration reaches an unstable condition thereby providing a precautionary warning of an approach to an unstable condition.

2. The structure as defined in claim 1 wherein said sensing means includes a housing mounted stationarily with respect to the vehicle, said mercury switch assemblies being disposed in said housing, inclined brackets in said housing supporting the mercury switch assemblies thereon, said adjustment means including screw-threaded members extending externally of the housing and being connected to the respective brackets for varying the angle of inclination of the brackets, spring means associated with each screw-threaded member for maintaining the bracket biased to its adjusted position.

3. The structure as defined in claim 1 including means delaying actuation of the brake means in response to intermittent acceleration signals caused by uneven roadways oVer which the vehicle travels thereby actuating the brake means only in response to lateral acceleration causing an unstable condition.

4. The structure as defined in claim 1 wherein said sensing means includes a housing mounted stationarily with respect to the vehicle, said mercury switch assemblies being disposed in said housing, inclined brackets in said housing supporting the mercury switch assemblies thereon, said adjustment means including screw-threaded members extending externally of the housing and being connected to the respective brackets for varying the angle of inclination of the brackets, spring means associated with each screw-threaded member for maintaining the bracket biased to its adjusted position, means delaying actuation of the brake means in response to intermittent acceleration signals caused by uneven roadways over which the vehicle travels thereby actuating the brake means only in response to lateral acceleration causing an unstable condition.

5. The structure as defined in claim 4 together with indicating light means energized by the mercury switch means to indicate a stable operating condition for the vehicle, and a warning light means operated when the brake means are actuated to indicate an unstable condition caused by lateral acceleration.

6. The structure as defined in claim 5 wherein said stable condition indicating light means is energized by said mercury switch means when the mercury therein is in normal condition closing a circuit between the lower contact of the pair of spaced contacts and the longitudinally elongated contact.