US4399653A — Automatic adjusting deceleration control for a hy…

Claim 1

Independent Claim 110 words

A control device for regulating the operation of a hydrostatic drive, which drive includes a prime mover, a variable displacement pump powered by the prime mover, and a hydraulic actuator means powered by the pump through a directional valve for driving a load through an operating cycle of acceleration, travel, deceleration and travel, said control device comprising: (a) means for determining whether the drive and load reach minimum speed coincident with the load reaching the position in the operating cycle where the load should be at minimum speed; and (b) means for correcting for variations therebetween by adjusting the point at which deceleration is initiated in the next operating cycle.

Claim 2

Dependent Claim 110 words

A control device for regulating the operation of a hydrostatic drive, which drive includes a prime mover, a variable displacement pump powered by the prime mover, and a hydraulic actuator means powered by the pump through a directional valve for driving a load through an operating cycle of acceleration, travel, deceleration and travel, said control device comprising: (a) means for determining whether the drive and load reach minimum speed coincident with the load reaching the position in the operating cycle where the load should be at minimum speed; and (b) means for correcting for variations therebetween by adjusting the point at which deceleration is initiated in the next operating cycle.

Claim 3

Dependent Claim 38 words

The control device in claim 1 wherein said means for determining includes: (a) means for sensing minimum pump displacement; and (b) means for sensing absolute load position within the operating cycle at the point of minimum pump displacement.

Claim 4

Dependent Claim 70 words

The control device in claim 2 wherein said means for correcting includes: (a) means for comparing the absolute load position sensed by said sensing means with the theoretical load position within the operating cycle at the point deceleration should be complete; and (b) means for advancing and retarding the point at which deceleration is initiated in the operating cycle responsive to compared variations between the sensed and theoretical load positions.

Claim 5

Dependent Claim 16 words

The control device in claim 3 wherein said means for sensing, comparing, and correcting are automated.

Claim 6

Dependent Claim 43 words

The control device in claim 3 wherein said means for correcting includes means for using a variation determined by said comparing means to advance or retard the point in the next operating cycle at which the pump initiates a change to minimum displacement.

Claim 7

Dependent Claim 47 words

The control device in claim 2 wherein said means for sensing minimum pump displacement includes an electrical limit switch connected to the minimum displacement stop for the pump, said means for sensing absolute load position includes an optical encoder, said means for correcting includes a programmable controller.

Claim 8

Dependent Claim 26 words

The control device in claim 1 wherein said means for correcting involves only adjusting the point at which deceleration is initiated in the next operating cycle.

Claim 9

Dependent Claim 108 words

A hydrostatic drive device, comprising: (a) a prime mover; (b) a positive displacement pump powered by said prime mover; (c) hydraulic actuator means, powered by said pump through a directional valve, for driving a load through an operating cycle of acceleration, travel, deceleration and travel; and (d) control means for regulating drive operation, said control means includes means for determining whether the drive device and load reach minimum speed coincident with the load reaching the position in the operating cycle where the load should be at minimum speed and for correcting for variations therefrom by adjusting the point at which deceleration is initiated in the next operating cycle.

Claim 10

Dependent Claim 108 words

A hydrostatic drive device, comprising: (a) a prime mover; (b) a positive displacement pump powered by said prime mover; (c) hydraulic actuator means, powered by said pump through a directional valve, for driving a load through an operating cycle of acceleration, travel, deceleration and travel; and (d) control means for regulating drive operation, said control means includes means for determining whether the drive device and load reach minimum speed coincident with the load reaching the position in the operating cycle where the load should be at minimum speed and for correcting for variations therefrom by adjusting the point at which deceleration is initiated in the next operating cycle.

Claim 11

Dependent Claim 40 words

The hydrostatic drive device in claim 8 wherein said means for determining includes means for sensing whether said pump output reaches minimum displacement coincident with load position reaching the point in the operating cycle at which deceleration should be complete.

Claim 12

Dependent Claim 69 words

The hydrostatic drive device in claim 8 wherein said means for determining includes: (a) means for sensing only minimum pump displacement; (b) means for sensing absolute load position within the operating cycle at the point of minimum pump displacement; and (c) means for comparing the absolute load position at minimum pump displacement following deceleration with theoretical load position within the operating cycle at the point deceleration should be complete.

Claim 13

Dependent Claim 50 words

The hydrostatic drive device of claim 8 wherein said means for correcting includes means for advancing and retarding the point at which deceleration is initiated in the operating cycle responsive to the compared absolute load position having attained a position less than or greater than the theoretical load position, respectively.

Claim 14

Dependent Claim 21 words

The hydrostatic drive device of claim 11 wherein said control means and said means for sensing, comparing and correcting are automated.

Claim 15

Dependent Claim 49 words

The hydrostatic drive device of claim 10 wherein said means for correcting includes means for using a variation determined by said comparing means to advance or retard the point in the next operating cycle at which said control means signals said pump to initiate a change to minimum displacement.

Claim 16

Dependent Claim 27 words

The hydrostatic drive device of claim 13 additionally comprising a pump acceleration/deceleration control which receives signals from said control means to initiate changes in said pump displacement.

Claim 17

Dependent Claim 41 words

The hydrostatic drive device of claim 10 wherein said means for correcting for a determined variation includes only adjusting the point in the next operating cycle at which said control means signals said pump to initiate a change to minimum displacement.

Claim 18

Independent Claim 125 words

A method for controlling the operation of a hydrostatically powered device, which includes a prime mover, a variable displacement hydraulic pump, hydraulic actuator means for driving a load through an operating cycle of acceleration, travel, deceleration and travel, and control means for regulating drive operation, comprising the steps of: (a) sensing minimum pump displacement of the device, (b) sensing absolute load position in the operating cycle at the point of minimum pump displacement following deceleration; (c) comparing the sensed load position with the theoretical load position within the operating cycle at the point deceleration should be complete; and (d) correcting for variations between the sensed and theoretical load positions by advancing or retarding the point at which deceleration is initiated in the next operating cycle.

Claim 19

Independent Claim 125 words

A method for controlling the operation of a hydrostatically powered device, which includes a prime mover, a variable displacement hydraulic pump, hydraulic actuator means for driving a load through an operating cycle of acceleration, travel, deceleration and travel, and control means for regulating drive operation, comprising the steps of: (a) sensing minimum pump displacement of the device, (b) sensing absolute load position in the operating cycle at the point of minimum pump displacement following deceleration; (c) comparing the sensed load position with the theoretical load position within the operating cycle at the point deceleration should be complete; and (d) correcting for variations between the sensed and theoretical load positions by advancing or retarding the point at which deceleration is initiated in the next operating cycle.

Claim 20

Dependent Claim 44 words

The method in claim 16 in which said correcting includes the step of using a variation determined by said comparing to adjust the point in the next operating cycle at which the control means signals the pump to initiate a change to minimum displacement.

Claim 21

Dependent Claim 45 words

The method in claim 16 in which said correcting only includes the step of using a variation determined by said comparing to adjust the point in the next operating cycle at which the control means signals the pump to initiate a change to minimum displacement.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1986-08-22	1987-02-21	1987-08-23	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1990-08-22	1991-02-21	1991-08-23	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1994-08-22	1995-02-21	1995-08-23	$7700.00	Window Closed / Lapsed

Automatic adjusting deceleration control for a hydrostatically powered device

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