Electronic control device

• US 3,915,325 A
• Filed: 08/16/1974
• Issued: 10/28/1975
• Est. Priority Date: 11/09/1972
• Status: Expired due to Term

• Current Assignee: Komatsu Dresser Company E Sunnyside 7TH St Libertyville IL A General Partnership Under The Uniform Partnership Act of The State of de
• Original Assignee: Marvin D. Jennings, Wayne W. Lark
• Inventors: Lark, Wayne W., Jennings, Marvin D.
• Primary Examiner(s): Spar, Robert J.
• Assistant Examiner(s): Weaver, Ross
• Application Number:
  US05/498,009
• Time in Patent Office: 438 Days
• Field of Search: 214/762,763,764,132,1CM 318/674
• US Class Current: 414/701
• CPC Class Codes: E02F 3/432 for keeping the bucket in a predetermined position or attitude
• CPC Class Codes: E02F 3/434 providing automatic sequences of movements, e.g. automatic dumping or loading, automatic return-to-dig
• CPC Class Codes: E02F 9/2004 Control mechanisms, e.g. control levers control levers per se G05G
• CPC Class Codes: E02F 9/2041 Automatic repositioning of implements, i.e. memorising determined positions of the implement for dipper-arms or bucket-arms E02F3/434, E02F3/437, E02F3/438, E02F3/439 take precedence

Abstract

An electronically controlled return to dig assembly, which after initial indexing, automatically positions the tool on a tractor loader. The electronic assembly operates to compare current in different circuits, upon detection of current imbalance hydraulic means are employed to achieve a zero imbalance which corresponds to the initial indexing position.

Claims

1. An implement control mechanism for use with the actuation lever of a hydraulically power implement, said actuation lever having a neutral position and an implement operating position with pressure means for constantly urging said lever to said neutral position, the improvement of said implement control mechanism comprising a master potentiometer, a slave potentiometer and voltage source electrically connected together in parallel, the wiper arm of said slave potentiometer operatively connected to the movement of said implement, voltage comparator means electrically connected between the wiper arms of said potentiometers for providing an electrical signal in response to a voltage difference between said wiper arms, and electrically responsive holding means energized by said electrical signal for providing a holding force to restrain said actuation lever in said implement operating position until a zero voltage difference condition occurs between said wiper arms, said holding force being greater than and opposite to the constant force exerted by said pressure means and terminating upon the occurrence of said zero voltage difference to cause said actuation lever to return to said neutral position.

2. The implement control mechanism of claim 1, wherein said electrically responsive holding means comprises an electromagnet and wherein said actuation lever includes a latching arm portion of magnetic permeable material that is disposed within the magnetic field of force of said electromagnet when said actuation lever is placed in said implement operating position, the magnetic attraction of said magnetic field on said latchinG arm portion being greater than and opposite to the constant force exerted by said pressure means and being terminated upon the occurrence of said zero voltage difference to cause said actuation lever to return to said neutral position.

3. An implement control mechanism for a tractor having a pair of boom arms, a bucket pivotally supported between said boom arms on an axis transverse to the longitudinal axis of said tractor, a hydraulic cylinder for effecting rotation of said bucket about said transverse axis, a hydraulic circuit including valve means for regulating the flow of hydraulic fluid to said hydraulic cylinder, lever means operable between neutral and roll position connected to said valve means in such a manner to cause said bucket to rotate when said lever means is in said roll position, and return spring means for constantly urging said lever means towards said neutral position, the improvement of said implement control mechanism comprising a master potentiometer, a slave potentiometer and an electrical voltage source electrically connected together in parallel, voltage comparator means electrically connected between the wiper arms of said potentiometers for providing an electrical signal in response to a voltage difference between said wiper arms, said slave potentiometer being operatively connected between said bucket and said boom arms in such a manner that a change in the angular orientation of said bucket causes a proportional displacement of said slave potentiometer wiper arm, and electromagnet means energized by said electrical signal for providing a holding force greater than and opposite to the force exerted by said return spring means to hold said lever means in said roll position until the bucket rotates to a pre-set angular orientation whereupon there occurs a zero voltage difference between said wiper arms to deenergize said electromagnet means and thereby permit the force of said return spring means to return said lever means toward said neutral position.

4. The implement control mechanism of claim 3, wherein said lever means includes a latching arm portion of magnetic permeable material that is disposed within the magnetic field of force of said electromagnet means when said lever means is placed in said roll position the magnetic attraction of said magnetic field on said latching arm portion being greater than and opposite to the constant force exerted by said pressure means and being terminated upon the occurrence of said zero voltage difference to cause said actuation lever to return to said neutral position.