Throttle signal modifying circuit

• US 5,231,965 A
• Filed: 11/23/1992
• Issued: 08/03/1993
• Est. Priority Date: 11/23/1992
• Status: Expired due to Term

• Current Assignee: Deere & Company
• Original Assignee: Deere & Company
• Inventors: Muzzy, Norman E.
• Primary Examiner(s): MILLER, CARL STUART
• Application Number:
  US07/980,077
• Time in Patent Office: 253 Days
• Field of Search: 123/325, 123/333, 123/357, 123/358, 123/494, 414/526
• US Class Current: 123/325
• CPC Class Codes: F02D 11/105 characterised by the function converting demand to actuation, e.g. a map indicating relations between an accelerator pedal position and throttle valve opening or target engine torque
• CPC Class Codes: F02D 41/28 Interface circuits

Abstract

An engine governor system includes an electronic governor which controls the fuel supply to an engine in response to an throttle signal supplied by a throttle potentiometer which coupled to a throttle lever. A circuit is connected between the throttle potentiometer and a potential source. The circuit includes a normally closed foot-operated deceleration switch connected in parallel with a first variable resistor, both connected in series with a third variable resistor. Closing the foot-operated switch will reduce the throttle signal by an amount controlled by the adjustment of the first variable resistor. The maximum possible throttle signal can be controlled by the adjustment of the second variable resistor.

Claims

1. In an engine governor system having an electronic governor, an operator controlled throttle device and a throttle position sensor coupled to the throttle device and connected to inputs of the electronic governor, the throttle position sensor comprising a throttle potentiometer connected to a potential source and with a tap element generating a variable magnitude throttle signal which is utilized by the electronic governor, the engine governor system also having modifying means coupled between the potential source and the throttle potentiometer for modifying the throttle signal supplied by the tap element of the throttle potentiometer, the improvement wherein the modifying means comprises:

a normally closed switch having a first terminal connected to the potential source and a second terminal coupled to the throttle potentiometer; and

a first variable resistor connected between the first and second terminals of the normally closed switch.

2. The invention of claim 1, further comprising:

a second variable resistor connected between the second terminal of the switch and the throttle position sensor.