Scraper blade control apparatus
First Claim
1. Apparatus for controlling the positioning of an element, said apparatus comprising:
- a three-position operation lever having HOLD, UP, and DOWN positions, said operation lever being actuatable by an operator for generating specified electrical signals at respective operating positions of the operation lever for controlling the positioning of said element;
at least one solenoid pilot valve which is operated in response to an electrical command signal;
a controller for providing an electrical command signal to the at least one solenoid pilot valve in response to at least one electrical signal including a specified electrical signal from said operation lever;
a four-position hydraulic control valve having HOLD, UP, DOWN, and FLOAT positions, wherein said hydraulic control valve is selectively actuated to a respective one of the HOLD, UP, DOWN and FLOAT positions in response to pilot pressure from said at least one solenoid pilot valve;
a hydraulic cylinder which is operated by hydraulic oil supplied from the hydraulic control valve; and
a control device for generating an electrical signal indicating that the FLOAT position is desired and for inputting to the controller the electrical signal indicating that the FLOAT position is desired, whereby said controller causes said at least one solenoid pilot valve to move said hydraulic control valve to the FLOAT position in response to an actuation of said control device and to maintain said hydraulic control valve at the FLOAT position upon the release of the operation lever by the operator.
1 Assignment
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Accused Products
Abstract
In an apparatus for controlling the vertical movement of a scraper blade (18) of a bulldozer, a four-position hydraulic control valve (12), having HOLD, UP, DOWN, and FLOAT positions, maintains the scraper blade in the FLOAT condition without requiring a detent mechanism, even when the three-position operation lever (1, 51) is released with the hydraulic control valve (12) in the FLOAT position. The operation lever (1, 51), having HOLD, UP, and DOWN positions, provides electrical signals to a controller (4) for actuating the hydraulic control valve (12) with pilot pressures provided via solenoid pilot valves (6, 7). A hydraulic cylinder (19), connected to the scraper blade (18), is actuated by hydraulic oil from the hydraulic control valve (12). A control device (2, 52), for generating an electrical signal for the FLOAT position and transmitting that electrical signal to the controller (4), is provided on the three-position operation lever (1, 51), so that the hydraulic control valve (12) is held at the FLOAT position in response to the electrical signal from the control device (2, 52).
24 Citations
20 Claims
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1. Apparatus for controlling the positioning of an element, said apparatus comprising:
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a three-position operation lever having HOLD, UP, and DOWN positions, said operation lever being actuatable by an operator for generating specified electrical signals at respective operating positions of the operation lever for controlling the positioning of said element; at least one solenoid pilot valve which is operated in response to an electrical command signal; a controller for providing an electrical command signal to the at least one solenoid pilot valve in response to at least one electrical signal including a specified electrical signal from said operation lever; a four-position hydraulic control valve having HOLD, UP, DOWN, and FLOAT positions, wherein said hydraulic control valve is selectively actuated to a respective one of the HOLD, UP, DOWN and FLOAT positions in response to pilot pressure from said at least one solenoid pilot valve; a hydraulic cylinder which is operated by hydraulic oil supplied from the hydraulic control valve; and a control device for generating an electrical signal indicating that the FLOAT position is desired and for inputting to the controller the electrical signal indicating that the FLOAT position is desired, whereby said controller causes said at least one solenoid pilot valve to move said hydraulic control valve to the FLOAT position in response to an actuation of said control device and to maintain said hydraulic control valve at the FLOAT position upon the release of the operation lever by the operator. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. A construction machine having a scraper blade and an apparatus for controlling the vertical positioning of said scraper blade, said apparatus comprising:
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a three-position manually actuatable operation lever having HOLD, UP, and DOWN positions, said operation lever being actuatable by an operator for generating specified electrical signals at respective operating positions of the operation lever for controlling the positioning of said scraper blade; at least one solenoid pilot valve which is operated in response to an electrical command signal; a controller for providing an electrical command signal to the at least one solenoid pilot valve in response to at least one electrical signal including a specified electrical signal from said operation lever; a four-position hydraulic control valve having HOLD, UP, DOWN, and FLOAT positions, wherein said hydraulic control valve is selectively actuated to a respective one of the HOLD, UP, DOWN, and FLOAT positions in response to pilot pressure from said at least one solenoid pilot valve; a hydraulic cylinder which is operated by hydraulic oil supplied from the hydraulic control valve, said hydraulic cylinder being adapted to move said scraper blade; and a control device for generating an electrical signal indicating that the FLOAT position is desired and for inputting to the controller the electrical signal indicating that the FLOAT position is desired, whereby said controller causes said at least one solenoid pilot valve to move said hydraulic control valve to the FLOAT position in response to an actuation of said control device and to maintain said hydraulic control valve at the FLOAT position upon the release of the operation lever by the operator. - View Dependent Claims (16, 17, 18, 19, 20)
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Specification