Pipelayer hydraulic drawworks with free-fall

Claim 2

In a system for operating and controlling a winding gear driven by a rotary hydraulic motor of the kind including a first member having a plurality of radial bores, a motor element displaceable in each of the bores and each having an associated driving means, a cam ring having cam faces engaged by the driving means and means for selectively supplying hydraulic fluid to the bores to displace the motor elements radially in a predetermined sequence and by pressure engagement of the driving means with the cam faces to produce relative rotation between the cam ring and said first member, the system including pump means for supplying hydraulic fluid to the hydraulic motor, normally applied brake means for said winding gear, fluid pressure means including fluid communication means for releasing said brake means, the improvement comprising; free-run means including fluid communication means for applying to the motor elements of the hydraulic motor a hydraulic pressure differential to displace the motor elements radially inwardly and withdraw the associated driving means from contact with the cam faces of the cam ring whereby the cam ring can rotate freely, said free-run means including means for preventing said fluid pressure means from releasing said brake means until said pressure differential has been developed to condition said motor elements and associated driving means to move radially inwardly away from contact with said cam faces of said cam ring, the hydraulic pressure for the free-run means being derived from a source separate from the pump means supplying the motor.

Claim 3

The invention of claim 1 including a casing for said hydraulic motor and means for applying, on actuation of the free-run means, a hydraulic pressure in the interior of said casing of the motor higher than that obtaining in said bores.

Claim 4

The invention of claim 1 including means for reducing, on actuation of the free-run means, standing hydraulic pressure in said bores.

Claim 5

The invention of claim 2 further including valve means for actuating the free-run means.

Claim 6

The invention of claim 4 including a casing for said hydraulic motor and wherein said valve means are adapted, on actuation, to connect a source of hydraulic pressure to the interior of said casing.

Claim 7

The invention of claim 5 further including means for maintaining a standing pressure in the bores when the motor is idle and wherein said valve means, on actuation, operate means for releasing said standing pressure from the bores of the motor.

Claim 8

In a system for operating and controlling a winding gear driven by a rotary hydraulic motor of the kind including a first member having a plurality of radial bores, a motor element displaceable in each of the bores and each having an associated driving means, a cam ring having cam faces engaged by the driving means and means for selectively supplying hydraulic fluid to the bores to displace the motor elements radially in a predetermined sequence and by pressure engagement of the driving means with the cam faces to produce relative rotation between the cam ring and said first member, the system including pump means for supplying hydraulic fluid to the hydraulic motor, normally applied brake means for said winding gear, fluid pressure means including fluid communication means for releasing said brake means, the improvement comprising; free-run means including fluid communication means for applying to the motor elements of the hydraulic motor a hydraulic pressure differential to displace the motor elements radially inwardly and withdraw the associated driving means from contact with the cam faces of the cam ring whereby the cam ring can rotate freely, said free-run means including means for preventing said fluid pressure means from releasing said brake means until said pressure differential has been developed to condition said motor elements and associated driving means to move radially inwardly away from contact with said cam faces of said cam ring, valve means for actuating the free-run means, a casing for hydraulic motor and wherein said valve means are adapted, on actuating, to connect a source of hydraulic pressure to the interior of said casing, means for maintaining a standing pressure in the bores when the motor is idle and wherein said valve means, on actuation, operate means for releasing said standing pressure from the bores of the motor, said valve means, on restoration to its normal position after actuation, acting to connect a source of hydraulic pressure to the bores of the motor to restore the standing pressure.

Claim 9

In a system for operating and controlling a winding gear driven by a rotary hydraulic motor of the kind including a first member having a plurality of radial bores, a motor element displaceable in each of the bores and each having an associated driving means, a cam ring having cam faces engaged by the driving means and means for selectively supplying hydraulic fluid to the bores to displace the motor elements radially in a predetermined sequence and by pressure engagement of the driving means with the cam faces to produce relative rotation between the cam ring and said first member, the system including pump means for supplying hydraulic fluid to the hydraulic motor, normally applied brake means for said winding gear, fluid pressure means including fluid communication means for releasing said brake means, the improvement comprising; free-run means including fluid communication means for applying to the motor elements of the hydraulic motor a hydraulic pressure differential to displace the motor elements radially inwardly and withdraw the associated driving means from contact with the cam faces of the cam ring whereby the cam ring can rotate freely, said free-run means including means for preventing said fluid pressure means from releasing said brake means until said pressure differential has been developed to condition said motor elements and associated driving means to move radially inwardly away from contact with said cam faces of said cam ring, valve means for actuating the free-run means, a casing for hydraulic motor and wherein said valve means are adapted, on actuating, to connect a source of hydraulic pressure to the interior of said casing, means for maintaining a standing pressure in the bores when the motor is idle and wherein said valve means, on actuation, operate means for releasing said standing pressure from the bores of the motor, said valve means, on restoration to its normal position after actuation, acting to connect a source of hydraulic pressure to the bores of the motor to restore the standing pressure.

Claim 10

The invention of claim 7 wherein said valve means, on restoration of its normal position after actuation, connect a source of hydraulic pressure to the bores of the motor to restore the standing pressure, said means for preventing brake means release being also provided for ensuring that the brake means is applied before the standing pressure is restored.

Claim 11

In a system for operating and controlling a winding gear driven by a reversible rotary hydraulic motor, driving means for selectively supplying hydraulic fluid to said rotary hydraulic motor to rotate said hydraulic motor and said winding gear, said driving means including first supply means for supplying hydraulic pressure fluid to said hydraulic motor, normally applied brake means for said winding gear, fluid pressure means including fluid communication means for releasing said brake means, free-run means including fluid communication means foR applying to a portion of the hydraulic motor a hydraulic pressure to allow said hydraulic motor to rotate freely without load, said free-run means including second supply means for supplying said hydraulic motor portion, said second supply means including a source of hydraulic fluid separate from the source of hydraulic fluid for said drive means, said free-run means including means for preventing said fluid pressure means from releasing said brake means until said hydraulic pressure has been supplied to said portion of said motor to condition said motor to rotate freely without load, said driving means for said reversible rotary hydraulic motor further including a motor control valve for controlling flow of hydraulic fluid to said hydraulic motor for driving rotation thereof, said control valve having a first portion for supplying fluid to cause said motor to rotate in a first direction, a second position for supplying fluid to cause said motor to rotate in the reverse direction, and a neutral position in which fluid flow to and from said hydraulic motor is blocked and a hydraulic fluid lock is created which retards rotation of said hydraulic motor in either of said first or reverse directions, said free-run means further including a secondary valve means separate from said motor control valve for controlling the supply of hydraulic fluid pressure to said motor portion.

Claim 12

In a system for operating and controlling a winding gear driven by a reversible rotary hydraulic motor, driving means for selectively supplying hydraulic fluid to said rotary hydraulic motor to rotate said hydraulic motor and said winding gear, said driving means including first supply means for supplying hydraulic pressure fluid to said hydraulic motor, normally applied brake means for said winding gear, fluid pressure means including fluid communication means for releasing said brake means, free-run means including fluid communication means foR applying to a portion of the hydraulic motor a hydraulic pressure to allow said hydraulic motor to rotate freely without load, said free-run means including second supply means for supplying said hydraulic motor portion, said second supply means including a source of hydraulic fluid separate from the source of hydraulic fluid for said drive means, said free-run means including means for preventing said fluid pressure means from releasing said brake means until said hydraulic pressure has been supplied to said portion of said motor to condition said motor to rotate freely without load, said driving means for said reversible rotary hydraulic motor further including a motor control valve for controlling flow of hydraulic fluid to said hydraulic motor for driving rotation thereof, said control valve having a first portion for supplying fluid to cause said motor to rotate in a first direction, a second position for supplying fluid to cause said motor to rotate in the reverse direction, and a neutral position in which fluid flow to and from said hydraulic motor is blocked and a hydraulic fluid lock is created which retards rotation of said hydraulic motor in either of said first or reverse directions, said free-run means further including a secondary valve means separate from said motor control valve for controlling the supply of hydraulic fluid pressure to said motor portion.

Claim 13

In a system for operating and controlling a winding gear driven by a rotary hydraulic motor, driving means for selectively supplying hydraulic fluid to said rotary hydraulic motor to rotate said hydraulic motor and said winding gear, said driving means including first supply means for supplying hydraulic pressure fluid to said hydraulic motor, normally applied brake means for said winding gear, fluid pressure means including fluid communication means for releasing said brake means, free-run means including fluid communication means for applying to a portion of the hydraulic motor a hydraulic pressure to allow said hydraulic motor to rotate freely without load, said free-run means including second supply means for supplying said hydraulic motor portion, said second supply means including a source of hydraulic fluid separate from the source of hydraulic fluid for said drive means, said free-run means including means for preventing said fluid pressure means from releasing said brake means until said hydraulic pressure has been supplied to said portion of said motor to condition said motor to rotate freely without load, said free-run means further including tertiary valve means for preventing said rotary hydraulic motor from returning from the freely rotating condition to the driving condition prior to the re-application of said brake means.

Claim 14

In a system for operating and controlling a winding gear driven by a rotary hydraulic motor, driving means for selectively supplying hydraulic fluid to said rotary hydraulic motor to rotate said hydraulic motor and said winding gear, said driving means including first supply means for supplying hydraulic pressure fluid to said hydraulic motor, normally applied brake means for said winding gear, fluid pressure means including fluid communication means for releasing said brake means, free-run means including fluid communication means for applying to a portion of the hydraulic motor a hydraulic pressure to allow said hydraulic motor to rotate freely without load, said free-run means including second supply means for supplying said hydraulic motor portion, said second supply means including a source of hydraulic fluid separate from the source of hydraulic fluid for said drive means, said free-run means including means for preventing said fluid pressure means from releasing said brake means until said hydraulic pressure has been supplied to said portion of said motor to condition said motor to rotate freely without load, said free-run means further including tertiary valve means for preventing said rotary hydraulic motor from returning from the freely rotating condition to the driving condition prior to the re-application of said brake means.

Claim 15

In a system for operating and controlling a winding gear driven by a rotary hydraulic motor of the kind including a first member having a plurality of radial bores, a motor element displaceable in each of the bores and each having an associated driving means, a cam ring having cam faces engaged by the driving means and means for selectively supplying hydraulic fluid to the bores to displace the motor elements radially in a predetermined sequence and by pressure engagement of the driving means with the cam faces to produce relative rotation between the cam ring and said first member, the system including pump means for supplying hydraulic fluid to the hydraulic motor, normally applied brake means for said winding gear, fluid pressure means including fluid communication means for releasing said brake means, the improvement comprising; free-run means including fluid communication means for applying to the motor elements of the hydraulic motor a hydraulic pressure differential to displace the motor elements radially inwardly and withdraw the associated driving means from contact with the cam faces of the cam ring whereby the cam ring can rotate freely, said free-run means including means for preventing said fluid pressure means from releasing said brake means until said pressure differential has been developed to condition said motor elements and associated driving means to move radially inwardly away from contact with said cam faces of said cam ring, an operator''s control for the motor wherein the free-run means includes means coupled to the operator''s motor control for ensuring that the free-run means can only be actuated when the motor control is in the off position.

Claim 16

In a system for operating and controlling a winding gear driven by a rotary hydraulic motor of the kind including a first member having a plurality of radial bores, a motor element displaceable in each of the bores and each having an associated driving means, a cam ring having cam faces engaged by the driving means and means for selectively supplying hydraulic fluid to the bores to displace the motor elements radially in a predetermined sequence and by pressure engagement of the driving means with the cam faces to produce relative rotation between the cam ring and said first member, the system including pump means for supplying hydraulic fluid to the hydraulic motor, normally applied brake means for said winding gear, fluid pressure means including fluid communication means for releasing said brake means, the improvement comprising; free-run means including fluid communication means for applying to the motor elements of the hydraulic motor a hydraulic pressure differential to displace the motor elements radially inwardly and withdraw the associated driving means from contact with the cam faces of the cam ring whereby the cam ring can rotate freely, said free-run means including means for preventing said fluid pressure means from releasing said brake means until said pressure differential has been developed to condition said motor elements and associated driving means to move radially inwardly away from contact with said cam faces of said cam ring, an operator''s control for the motor wherein the free-run means includes means coupled to the operator''s motor control for ensuring that the free-run means can only be actuated when the motor control is in the off position.

Claim 17

In a system for operating and controlling a winding gear driven by a rotary hydraulic motor, driving means for selectively supplying hydraulic fluid to said rotary hydraulic motor to rotate said hydraulic motor and said winding gear, said driving means including first supply means for supplying hydraulic pressure fluid to said hydraulic motor, normally applied brake means for said winding gear, fluid pressure means including fluid communication means for releasing said brake means, free-run means including fluid communication means for applying to a portion of the hydraulic motor a hydraulic pressure to allow said hydraulic motor to rotate freely without load, said free-run means including second supply means for supplying said hydraulic motor portion, said second supply means including a source of hydraulic fluid separate from the source of hydraulic fluid for said drive means, said free-run means including means for preventing said fluid pressure means from releasing said brake means until said hydraulic pressure has been supplied to said portion of said motor to condition said motor to rotate freely without load.

Claim 18

In a system for operating and controlling a winding gear driven by a rotary hydraulic motor, driving means for selectively supplying hydraulic fluid to said rotary hydraulic motor to rotate said hydraulic motor and said winding gear, said driving means including first supply means for supplying hydraulic pressure fluid to said hydraulic motor, normally applied brake means for said winding gear, fluid pressure means including fluid communication means for releasing said brake means, free-run means including fluid communication means for applying to a portion of the hydraulic motor a hydraulic pressure to allow said hydraulic motor to rotate freely without load, said free-run means including second supply means for supplying said hydraulic motor portion, said second supply means including a source of hydraulic fluid separate from the source of hydraulic fluid for said drive means, said free-run means including means for preventing said fluid pressure means from releasing said brake means until said hydraulic pressure has been supplied to said portion of said motor to condition said motor to rotate freely without load.

Claim 19

The invention of claim 12 wherein said rotary hydraulic motor is reversible and said hydraulic motor drive means further includes a motor control valve for controlling flow of hydraulic fluid to said hydraulic motor for driving rotation thereof, said control valve having a first position for supplying fluid to cause said motor to rotate in a first direction, a second position for supplying fluid to cause said motor to rotate in the reverse direction, and a neutral position in which fluid flow to and from said hydraulic motor is blocked and a hydraulic fluid lock is created which retards rotation of said hydraulic motor in either of said first or reverse directions.