Safety disengagement device for automotive speed control system

• US 4,355,607 A
• Filed: 09/08/1980
• Issued: 10/26/1982
• Est. Priority Date: 09/08/1980
• Status: Expired due to Term

• Current Assignee: Zemco Incorporated
• Original Assignee: Zemco Incorporated
• Inventors: Blaney, Peter G.
• Primary Examiner(s): Myhre, Charles J.
• Assistant Examiner(s): Dolinar, Andrew M.
• Application Number:
  US06/185,352
• Time in Patent Office: 778 Days
• Field of Search: 123/350, 123/351, 123/352, 123/198 D, 180/170, 180/171, 180/176, 180/178, 180/179
• US Class Current: 123/350
• CPC Class Codes: B60K 28/00 Safety devices for propulsion-unit control, specially adapted for, or arranged in, vehicles, e.g. preventing fuel supply or ignition in the event of potentially dangerous conditions for electrically-propelled vehicles B60L3/00; road vehicle drive control systems for purposes not related to the control of a particular sub-unit B60W30/00; drive control systems specially adapted for autonomous road vehicles B60W60/00
• CPC Class Codes: B60K 28/14 responsive to accident or emergency, e.g. deceleration, tilt of vehicle
• CPC Class Codes: B60K 31/10 and means for comparing one electrical quantity, e.g. voltage, pulse, waveform, flux, or the like, with another quantity of a like kind, which comparison means is involved in the development of a pressure which is fed into the controlling means
• CPC Class Codes: F02B 1/04 with fuel-air mixture admission into cylinder
• CPC Class Codes: F02B 77/08 Safety, indicating or supervising devices thermal insulation F02B77/11; rendering engines inoperative or idling F02D17/04; dependent on lubricating conditions F01M1/22; dependent on cooling F01P11/14

Abstract

For use on an automotive vehicle equipped with an internal combustion engine and an automatic speed control system, a device for detecting accidental engine load removal and for providing disengagement of the speed control system to prevent an engine runaway condition. The device comprises a circuit that compares present engine speed with a previous engine speed furnished after a time delay to produce an output signal when a preselected engine speed differential occurs during the delay period. The output signal is utilized to disengage the speed control system directly or alternatively, to turn off the engine ignition system.

Claims

1. A device for automatically disengaging a speed control system on a vehicle with an internal combustion gasoline engine having an ignition system, said device comprising:

(1) an input buffer circuit adapted for connection to the vehicle ignition system for isolating ignition noise;

(2) a tachometer circuit connected to said buffer circuit for generating a signal proportional to the vehicle engine speed;

(3) a delay circuit connected to the output of said tachometer circuit for generating a signal proportional to the engine speed but delayed in time;

(4) comparator means for comapring the tachometer circuit output to the delay circuit output and for producing a trigger signal whenever the tachometer signal exceeds the delayed signal by a preselected amount; and

an output switch means connected to said comparator means for controlling the operation of the vehicle speed control system, whereby, whenever the comparator means is triggered, the output switch means will cause the speed control system to disengage.

2. The device of claim 1 includes a reference circuit connected to said comparator means for detecting when the vehicle engine speed exceeds a preselected maximum value and for triggering said output switch means to disengage the speed control whenever an engine overspeed condition occurs.

3. The device as described in claim 1 wherein said tachometer circuit comprises an operational amplifier that receives an input from said buffer circuit and provides an output with a voltage proportional to engine speed.

4. The device as described in claim 1 wherein said delay circuit comprises a resistor and a capacitor for providing a delayed output of said tachometer circuit with its output at a later predetermined time interval.