US3315820A

US3315820A - Crane with winch releasing means

Info

Publication number: US3315820A
Application number: US487552A
Authority: US
Inventors: Robert E Stauffer
Original assignee: Jeffrey Galion Manufacturing Co
Current assignee: Jeffrey Galion Manufacturing Co
Priority date: 1965-09-15
Filing date: 1965-09-15
Publication date: 1967-04-25
Anticipated expiration: 1984-04-25
Also published as: DE1456469A1; DE1456469B2; GB1118978A

Description

April 25, 1957 R. E. STAUFFER CRANE WITH WINCH BELEASING MEANS 2 Sheets-Sheet 1 Filed Sept. 15, 1965 m R F MP W U L 5 T R E w 2 Sheets-Sheet 2 Filed Sept. 15, 1965 wxiwm :02;

KMOZIC Q OHU 200m H NE United States Patent 3,315,820 CRANE WITH WINCH RELEASING MEANS Robert E. Staufier, Galion, Ohio, assignor to Jeffrey Gallon Manufacturing Company, a corporation of Ohio Filed Sept. 15, 1965, Ser. No. 487,552 Claims. (Cl. 21235) The instant invention relates to cranes, and more particularly to a system for operation of the extensible boom and the winch in a crane.

In the crane to which this invention is applicable the boom is extensible and retractable for utilization of the boom to reach within a wide area for picking up and for placing loads at any position within such area. The crane includes a winch on the boom with a line that extends over the boom and depends from the boom. A line block is attached to the line and has a hook, or other suitable means for holding the load. By operation of the winch, the line may be paid out or reeled in to lower or raise the line block, respectively. If the winch is not operated in the course of extending the boom, then the depending portion of the line and the line block will be drawn up against the boom, and as the boom extension continues, a substantial pulling force is developed in the line. In order to limit this pulling force on the line, there is provided in the boom-winch operating system means by which the winch is released, such that it may pay out the line as the boom is extended, in response to the line pulling force, with the result that the pulling force on the line is limited.

It is an object of this invention to provide an improved operating system in a crane for the extensible boom and winch.

It is another object of the instant invention to provide means in a crane whereby the line may be paid out as the boom is extended.

It is a further object of the instant invention to provide an operating system in a crane in which the winch is released during the extension of the boom so that the line may be paid out from the winch to the extent of the length of extension of the boom.

It is also an object of the instant invention to provide means in a crane for limiting the pulling force in the line during the extension of the boom.

Still another object of the instant invention is to provide an operating system in a crane in which the line is paid out from the winch as the boom is extended.

Other objects of the invention will appear hereinafter, the novel features and combinations being set forth in the appended claims.

In the drawings:

FIG. 1 is a side elevational view, in section, of the crane boom and Winch; and

, FIG. 2 is a diagrammatic illustration of the hydraulic operating system.

Referring to FIG. 1, the crane has an extensible boom 10 which is mounted on an upstanding pedestal 11. At the bottom of the pedestal 11, there is a turntable 12 that is rotatably supported on the base frame 13. The turntable 12 is rotatable by suitable driving means on the base frame 13, so that the boom 10 may be swung laterally in -an are from place to place.

The boom 10 has a lower boom 15 which is connected to the pedestal 11 by a pivot 16 for lifting and lowering the boom 10 in an are about the pivot 16, in order to reach different elevations. A boom lift cylinder 17 has its base end connected to the turntable 12 by a pivot 18. The boom lift cylinder 17 is disposed in an upright position in the pedestal 11 and its piston rod end is connected to the lower boom 15 by a pivot 19. The boom 10 is lifted by extension of the cylinder 17, and is lowered by retraction of the cylinder 17.

An upper boom 20 is disposed within the lower boom 15. The upper boom 20 is telescoped in the lower boom 15 so that it may be extended and retracted relatively to the lower boom 15. Within the lower and

upper booms

15, 20 there is a boom crowd cylinder 21, which comprises two separate hydraulic cylinders 21a, 21b. The two cylinders 21a, 21b are arranged in tandem, with an intermediate articulated connection 22 that includes suitable flow passages for the flow of hydraulic fluid from one cylinder to the other. The crowd cylinder 21 may take the form of separate cylinders arranged in tandem, as illustrated herein, or it may be a single cylinder, or other similar power means for extending or retracting the boom 10. The lower end of the crowd cylinder 21 is connected to the lower boom 15 by a pivot 23, and the upper end of the crowd cylinder 21 is connected to the upper boom 20 by a pivot 24. Thus, the force of the crowd cylinder 21 is applied between the lower boom 15 and the upper boom 20 to extend and retract the latter to the extent of the extension and retraction of the crowd cylinder 21.

At the lower end of the lower boom 15, there is a winch 25 on which a hoist line 26 is reeled. The winch 25 is driven by a reversible hydraulic motor 27, which can be operated to rotate the winch 25 in one direction to pay out the line 26, and in the opposite direction to reel in the line 26.

The hoist line 26 extends from the winch 25 over the boom 10. At the upper end of the upper boom 20, there is a head block 28, which is secured to the upper boom 20. The head block 28 includes a plurality of sheaves 29. The hoist line 26 is reeved over the sheaves 29 and depends from the end of the boom 10. A line block 30 has a plurality of sheaves 31, and the hoist line 26 is reeved over the sheaves 31 to support the line block 30 in depending position on the line 26. A hook 32, or other device for holding a load, is secured to the line block 30. Preferably, the hoist line 26 is reeved through the head block 28 and the line block 30 with several parts of line, for a mechanical advantage to increase the load capacity of the hoist line 26. By way of example, the hoist line 26 may have a rated single line pull of approximately five thousand pounds. The hoist line 26 may be reeved through the head block 28 and the line block 30 in five parts, which provides a mechanical advantage of five, whereby the load capacity at the hook 32 is approximately twenty-five thousand pounds.

The winch 25 and the winch motor 27 include a brake which holds the winch 25 and the winch motor 27 in fixed position to prevent the hoist line 26 from being paid out from the winch 25. When the winch motor 27 is operated to rotate the Winch 25 to pay out the line 26, the brake is released as a part of the operation of the motor 27. When the winch 25 and its motor 27 are held in fixed position, there is a fixed length of hoist line 26 that extends over the boom 10. Upon extension of the boom 10, the depending part of the hoist line 26 is drawn upwardly until the line block 30 comes into engagement with the head block 28, which is at the limit of the line available. Further extension of the boom 10 produces a pulling force in the hoist line 26 between the head block 28 and the winch 25. Such line pulling force can break the line, with resultant damage to the equipment. There is also a serious risk involved by reason of the fact that there may be a load on the crane which would he suddenly dropped, in the event of line breakage. By way of example, the crowd cylinder 21 may be designed to apply a force of approximately twenty-nine thousand pounds between the lower boom 15 and the upper boom 20, for extension and retraction thereof. A force of this magnitude is commensurate with the load capacity of the crane. However, the force of twenty-nine thousand pounds is greatly in excess of the rated line pull of five thousand pounds, with the result that the line could be broken by the force of the crowd cylinder 21.

In accordance with this invention, the crane includes a system for operation of the boom 1i and the winch 25, such that as the boom is extended, the winch and the winch motor 27 are released, and in the event of development of an excessive line pulling force in the hoist line 26, such line pulling force is limited by paying out the line 26 from the winch 25.

In FIG. 2, there is illustrated the hydraulic system for operating the crane. A pump delivers the hydraulic fluid to the operating system. A system relief valve 36 is connected at the discharge side of the pump 35 and is selected for the desired relief pressure of the system. The relief pressure may be of the order of 1500 p.s.i., which is then the maximum operating pressure of the system.

A first control valve 37 is connected to the pump 35. The control valve 3'7 may be manually operated with a spring return to neutral position. The control valve 37 is connected to the double acting boom lift cylinder 17 and is reversible for delivering hydraulic fluid to the cylinder 17 in one direction for extension of the cylinder 17, and in the opposite direction for retraction of the cylinder 17. The hydraulic fluid is supplied to the boom lift cylinder 17 through a check valve 38, which prevents return flow of the hydraulic fluid, thereby to hold the cylinder 17 in extended position. To retract the cylinder 17, the hydraulic fluid is supplied to the cylinder 17 through a line 39. A pilot line 46 connects from the line 39 to a pilot operated relief valve 41. When hydraulic fluid is supplied through line 39, the pilot flow of fluid through the pilot line 49 opens the valve 41 to permit return flow of hydraulic fluid from the base end of the cylinder 17. The pilot operated relief valve 41 is connected across the check valve 38 to bypass the latter. The relief valve 41 has a spring return by which it is closed when the pilot flow through pilot line 41 steps.

A control valve 45 is connected in series with the control valve 37. The operation of the boom crowd cylinder 21 is controlled by the control valve 45. The control valve 45 may be manually operated with a spring return to neutral position, and is reversible for flow of hydraulic fluid to the double acting crowd cylinder 21 in opposite directions. Hydraulic fluid is supplied to the boom crowd cylinder 21 in one direction through the check valve 46 for extending the cylinder 21. The check valve 46 prevents return flow of hydraulic fluid, in order to maintain the cylinder 21 in fixed position. Hydraulic fluid is supplied to the boom crowd cylinder 21 in the opposite direc tion through line 47 for retracting the cylinder 21. A pilot line 48 is connected to the line 47 and to a pilot operated relief valve 45. When hydraulic fluid is supplied through line 47, the pilot flow of fluid through pilot line 48 opens the relief valve 49 to permit return flow of hydraulic fluid from the cylinder 21. Such return flow of hydraulic fluid bypasses the check valve 46, since the relief valve 49 is connected across the check valve 46. The pilot operated relief valve 49 has a spring return for closing the valve 49 when the pilot flow ceases.

Another control valve 52 is connected in series with the valve 45. The control valve 52 is reversible and may be a manually operated valve with a spring return to neutral position. The control valve 52 controls the supply of hydraulic fluid to the reversible hydraulic motor 27 of the winch 25, to drive the latter in opposite directions. Hydraulic fluid is supplied through check valve 53 to drive the winch motor 27 and the winch 25 to reel in the hoist line 26. This causes the line block 30 and any load on the hook 32 to be raised, and therefore, is referred to as the up direction of the winch. The check valve 53 prevents return flow from the winch motor 27.

Hydraulic fluid is supplied through line 54 to the winch motor 27, to rotate the latter in the opposite direction for driving the winch 25 to pay out the hoist line 26 and to lower any load that may be held on the hook 32. This is referred to as the down direction of the winch 25. A pilot line 55 is connected to the line 54 and to a pilot operated relief valve 56. When hydraulic fluid is supplied through the line 54, there is a pilot flow through the pilot line 55, which opens the relief valve 56 for return flow of hydraulic fluid from the winch motor 27. Such return flow bypasses the check valve 53, since the relief valve 56 is connected across the check valve 53. There is a spring return for the relief valve 56 to close the latter when the pilot flow ceases.

A winch brake 64' is applied to the winch 25 and the winch motor 27 to hold the winch 25 and its motor 27 in fixed position. The connection of the winch motor 27 to the winch 25 includes a suitable one-way clutch, or like device, which permits the winch motor 27 to drive the winch 25 in the up direction to reel in the hoist line 26. To operate the winch 25 and the winch motor 27 in the opposite direction to pay out the hoist line 26, it is necessary to release the winch brake 60. A single acting hydraulic cylinder 61 is connected to the brake for releasing the latter, when hydraulic fluid under pressure is supplied to the cylinder 61. A return spring 62 is applied to the single acting cylinder 61 for returning the brake 60 to hold the winch 25 and the winch motor 27.

A pilot line 63 is connected to the line 54. When hydraulic fluid is supplied to the winch motor 27 through the line 54, there is a pilot flow through the line 63 and through check valve 64 to the single acting cylinder 61, to operate the latter to overcome the force of the return spring 62 and thereby to release the brake 60. This permits operation of the winch motor 27 and the winch 25 to pay out the hoist line 26. Upon stopping the flow of hydraulic fluid through line 54, the winch brake 60 is again applied by the action of the return spring 62 on the cylinder 61. The flow regulator 65 permits a continuous trickle drainage of hydraulic fluid from the cylinder 61 and the lines to the tank for restoring the brake 60 to hold the winch 25 and its motor 27. The check valve 6% prevents flow of hydraulic fluid from the winch hydraulic circuit to the crowd cylinder hydraulic circuit.

When hydraulic fluid is supplied to the boom crowd cylinder 21 through check valve 46 for extension of the cylinder 21, there is a pilot flow of hydraulic fluid through pilot line 68 and through check valve 69 to the brake cylinder 61, which operates the latter to release the winch brake 60, which in turn releases the winch 25 and the winch motor 27. However, the winch motor 27 is not driven when there is no hydraulic fluid supplied to the winch motor 27 under control of the valve 52. As the boom 10 is extended by the cylinder 21, any line pull that develops in the hoist line 26, as previously described, and which is applied to the winch 25 as torque, tends to rotate the winch motor 27 and to drive the latter as a hydraulic pump with a blocked outlet.

A relief valve 70 is connected across the winch motor 27 and is normally closed to block the flow of hydraulic fluid when the motor 27 is driven as a pump. However, as the pulling force on the hoist line 26 increases, there will be a commensurate increase in the pressure of the hydraulic fluid in the motor 27. When the pressure of the hydraulic fluid exceeds the setting of the relief valve 70, the latter will be opened by such pressure, and there will be flow through the relief valve 70 and the motor 27. The motor 27 and winch 25 may then rotate in response to the pulling force developed in the hoist line 26 to pay out the line 26 from the winch 25. The setting of the relief valve 70 is higher than that of the system relief valve 36, and may be set at 1600 psi. In this operation, the check valve 64 blocks the flow of hydraulic fluid to the line 63 and thereby prevents the opening of the pilot operated relief valve 56. After the operation is completed the pressure of the hydraulic fluid in line 68 can drop off and does not reflect the load that may be on the boom crowd cylinder 21.

In the crane constructed in accordance with this invention an excessive line pulling force cannot be developed in the hoist line 26 during the operation of extending the boom 10. The winch 25 and its motor 27 are released when the boom is extended, and thus, the pulling force that may be developed in the hoist line 26 can pay out the line from the winch 25. Thus, any excessive line pulling force is limited to avoid line breakage and any equipment damage or other risk that might result from line breakage.

Obviously those skilled in the art may make various changes in the details and arrangement of parts without departing from the spirit and scope of the invention as defined by the claims hereto appended, and applicant therefore wishes not to be restricted to the precise construction herein disclosed.

Having thus described and shown an embodiment of the invention, what it is desired to secure by Letters Patent of the United States is:

1. In a crane, an extensible boom, a winch, a line reeled on the winch, said line extending from said winch over said boom to depend from the boom, a line block on said line and depending from the boom, means to hold said winch in fixed position to fix the length of line extending over said boom, reversible operating means to operate said winch in one direction to pay out said line and to lower said line block relatively to said boom or to operate said winch in the opposite direction to reel in said line and to raise said line block relatively to said boom, two direction power means to extend and to retract said extensible boom, reversible means to operate said boom power means in one direction to extend said boom or to operate said boom power means in the opposite direction to retract said boom, and means that is responsive to the extension of said boom by operation of said boom power means in said one direction to release said winch holding means in order to pay out said line from the winch by a pulling force on the line as the boom is extended.

2. In a crane, an extensible boom, a winch, a line reeled on the winch, said line extending from said winch over said boom to depend from the boom, a line block on said line and depending from the boom, means to hold said winch in fixed position to fix the length of line extending over said boom, reversible operating means to operate said winch in one direction to pay out said line and to lower said line block relatively to said boom or to operate said winch in the opposite direction to reel in said line and to raise said line block relatively to said boom, two direction hydraulic power means to extend and to retract said extensible boom, reversible means to supply hydraulic fluid in one direction to operate said boom hydraulic power means in one direction to extend said boom or to supply hydraulic fluid in the opposite direction to operate said boom hydraulic power means in the opposite direction to retract said boom, and means that is responsive to said hydraulic fluid in said one direction as the boom is extended by operation of said boom hydraulic power means to release said winch holding means in order to pay out said line from the winch by a pulling force on the line as the boom is extended.

3. In a crane, an extensible boom, a winch, a line reeled on the winch, said line extending from said winch over said boom to depend from the boom, a line block on said line and depending from the boom, a reversible hydraulic motor to operate said winch in one direction to pay out said line and to lower said line block relatively to said boom or to operate said winch in the opposite direction to reel in said line and to raise said line block relatively to said boom, means to hold said winch hydraulic motor and said winch in fixed position to fix the length of line extending over said boom, two direction hydraulic power means to extend and to retract said extensible boom, reversible means to supply hydraulic fluid in one direction o operate said boom hydraulic power means to extend said boom or to supply hydraulic fluid in the opposite direction to operate said boom hydraulic power means to retract said boom, and means that is responsive to said hydraulic fluid in said one direction as the boom is extended by operation of said boom hydraulic power means to release said holding means in order to pay out said line from the winch by a pulling force on the line as the boom is extended.

4. In a crane, an extensible boom, a winch, a line reeled on the winch, said line extending from said winch over said boom to depend from the boom, a line block on said line and depending from the boom, a reversible hydraulic motor to operate said winch in one direction to pay out said line and to lower said line block relatively to said boom or to operate said winch in the opposite direction to reel in said line and to raise said line block relatively to said boom, means to hold said winch hydraulic motor and said winch in fixed position to fix the length of line extending over said boom, two direction hydraulic power means to extend and to retract said extensible boom, reversible means to supply hydraulic fluid in one direction to operate said boom hydraulic power means to extend said boom or to supply hydraulic fluid in the opposite direction to operate said boom hydraulic power means to retract said boom, and means to release said holding means by said hydraulic fiuid in said one direction as the boom is extended by operation of said boom hydraulic power means, said line being paid out from the winch by a pulling force on the line as the boom is extended, said line pulling force acting on said winch hydraulic motor to drive the motor as a hydraulic pump, a valve connected across said winch hydraulic motor and being opened in response to the pressure of the hydraulic fluid when the winch hydraulic motor is driven as a pump for flow of hydraulic fluid through the motor and the valve.

5. In a crane, an extensible boom, a winch, a line reeled on the winch, said line extending from said winch over said boom to depend from the boom, a line block on said line and depending from the boom, a reversible motor to operate said winch in one direction to pay out said line and to lower said line block relatively to said boom or to operate said winch in the opposite direction to reel in said line and to raise said line block relatively to said boom, a brake to hold said winch motor and said winch in fixed position to fix the length of line extending over said boom, two direction power means to extend and to retract said extensible boom, reversible means to operate said boom power means in one direction to extend said boom or to operate said boom power means in the opposite direction to retract said boom, and means that is responsive to the extension of said boom by operation of said boom power means in said one direction to release said brake in order to release said winch motor and said winch in order to pay out said line from the winch by a pulling force on the line as the boom is extended.

6. In a crane, an extensible boom, a winch, a line reeled on the winch, said line extending from said winch over said boom to depend from the boom, a line block on said line and depending from the boom, means to hold said winch in fixed position to fix the length of line extending over said boom, a reversible hydraulic motor to operate said Winch in one direction to pay out said line and to lower said line block relatively to said boom or to operate said winch in the opposite direction to reel in said line and to raise said line block relatively to said boom, two direction power means to extend and to retract said extensible boom, reversible means to operate said boom power means in one direction to extend said boom or to operate said boom power means in the opposite direction to retract said boom, and means to release said winch holding means as the boom is extended by operation of said boom power means in said one direction, said line being paid out from the winch by a pulling force on the line as the boom is extended, said line pulling force acting on 'said winch hydraulic motor to drive the motor as a hydraulic pump, a valve connected across said winch hydraulic motor and being opened in response to the pressure of the hydraulic fluid when the winch hydraulic motor is driven as a pump for flow of hydraulic fluid through the motor and the valve.

7. In a crane, an extensible boom, a winch, a line reeled on the winch, said line extending from said winch over said boom to depend from the boom, a line block on said line and depending from the boom, reversible operating means to operate said Winch in one direction to pay out said line and to lower said line block relatively to said boom or to operate said winch in the opposite direction to reel in said line and to raise said line block relatively to said boom, a brake to hold the winch in fixed position to fix the length of line extending over said boom, two direction hydraulic power means to extend and to retract said extensible boom, reversible means to supply hydraulic fluid in one direction to operate said boom hydraulic power means to extend said boom or to supply hydraulic fluid in the opposite direction to operate said boom hydraulic power means to retract said boom, and means that is responsive to said hydraulic fluid in said one direction as the boom is extended by operation of said boom hydraulic power means to release said winch brake in order to pay out said line from the winch by a pulling force on the line as the boom is extended.

8. In a crane, an extensible boom, 21 winch, a line reeled on the winch, said line extending from said winch over said boom to depend from the boom, a line block on said line and depending from the boom, means to hold said winch in fixed position to fix the length of line extending over said boom, reversible operating means to operate said winch in one direction to pay out said line and to lower said line block relatively to said boom or to operate said winch in the opposite direction to reel in said line and to raise said line block relatively to said boom, a double acting hydraulic cylinder to extend and to retract said extensible boom, reversible means to supply hydraulic fluid in one direction to operate said hydraulic cylinder to extend said boom or to supply hy- :lraulic fluid in the opposite direction to operate said hydraulic cylinder to retract said boom, a check valve for said hydraulic fluid in said one direction to block return Flow of the hydraulic fluid from said hydraulic cylinder, 1 pilot operated valve connected across said check valve and operated by said hydraulic fluid in said opposite direction to open said valve for return flow of hydraulic Fluid from said hydraulic cylinder past said check valve, and means that is responsive to said hydraulic fluid in ;aid one direction as the boom is extended by operation )f said double acting hydraulic cylinder to release said vinch holding means in order to pay out said line from he winch by a pulling force on the line as the boom is :xtended.

9. In a crane, an extensible boom, a winch, a line 'eeled on the winch, said line extending from said winch )ver said boom to depend from the boom, a line block )n said line and depending from the boom, a reversible hydraulic motor to operate said winch in one direction pay out said line and to lower said line block relaively to said boom or to operate said winch in the op- )OSltC direction to reel in said line and to raise said line block relatively to said boom, a brake to hold said winch hydraulic motor and said winch in fixed posit-ion to fix the length of line extending over said boom, a double acting hydraulic cylinder to extend and to retract said extensible boom, reversible means to supply hydraulic fluid in one direction to operate said hydraulic cylinder to extend said boom or to supply hydraulic fluid in the opposite direction to operate said hydraulic cylinder to retract said boom, a check valve for said hydraulic fluid insaid one direction to block return flow of the hydraulic fluid from said hydraulic cylinder, a pilot operated valve connected across said check valve and operated by said hydraulic fluid in said opposite direction to open said valve for return flow of hydraulic fluid from said hydraulic cylinder past said check valve, and hydraulic power means that is responsive to said hydraulic fluid in said one direction as the boom is extended by operation of said double acting hydraulic cylinder to release said brake in order to pay out said line from the winch by a pulling force on the line as the boom is extended.

10. In a crane, an extensible boom, a Winch, a line reeled on the winch, said line extending from said winch over said boom to depend from the boom, a line block on said line and depending from the boom, a reversible hydraulic motor to operate said winch in one direction to pay out said line and to lower said line block relatively to said boom or to operate said winch in the opposite direction to reel in said line and to raise said line block relatively to said boom, a brake to hold said winch hydraulic motor and said Winch in fixed position to fix the length of line extending over said boom, a double acting hydraulic cylinder to extend and to retract said extensible boom, reversible means to supply hydraulic fluid in one direction to operate said hydraulic cylinder to extend said boom or to supply hydraulic fluid in the opposite direction to operate said hydraulic cylinder to retract said boom, a check valve for said hydraulic fluid in said one direction to block return flow of the hydraulic fluid from said hydraulic cylinder, a pilot operated valve connected across said check valve and operated by said hydraulic fluid in said opposite direction to open said valve for return flow of hydraulic fluid from said hydraulic cylinder past said check valve, and a single acting hydraulic cylinder to release said brake, spring return means for said single acting hydraulic cylinder to apply the brake to hold said winch motor and said winch, means to supply said hydraulic fluid in said one direction to said single acting cylinder to release said brake as the boom is extended by operation of said double acting hydraulic power cylinder in order to pay out said line from the winch by a pulling force on the line as the boom is extended.

References Cited by the Examiner UNITED sTATEs PATENTS 2,787,383 4/1957 Antosetal. 2,919,036 12/1959 Raymond 212- 3,047,160 7/1962 Paul 212 35 3,112,035 11/1963 Knight 212 ANDRES H. NIELSEN, Primary Examiner.

Claims

4. IN A CRANE, AN EXTENSIBLE BOOM, A WINCH A LINE REELED ON THE WINCH, SAID LINE EXTENDING FROM SAID WINCH OVER SAID BOOM TO DEPEND FROM THE BOOM, A LINE BLOCK ON SAID LINE AND DEPENDING FROM THE BOOM, A REVERSIBLE HYDRAULIC MOTOR TO OPERATE SAID WINCH IN ONE DIRECTION TO PAY OUT SAID LINE AND TO LOWER SAID LINE BLOCK RELATIVELY TO SAID BOOM OR TO OPERATE SAID WINCH IN THE OPPOSITE DIRECTION TO REEL IN SAID LINE AND TO RAISE SAID LINE BLOCK RELATIVELY TO SAID BOOM, MEANS TO HOLD SAID WINCH HYDRAULIC MOTOR AND SAID WINCH IN FIXED POSITION TO FIX THE LENGTH OF LINE EXTENDING OVER SAID BOOM, TWO DIRECTION HYDRAULIC POWER MEANS TO EXTEND AND TO RETRACT SAID EXTENSIBLE BOOM, REVERSIBLE MEANS TO SUPPLY HYDRAULIC FLUID IN ONE DIRECTION TO OPERATE SAID BOOM HYDRAULIC POWER MEANS TO EXTEND SAID BOOM OR TO SUPPLY HYDRAULIC FLUID IN THE OPPOSITE DIRECTION TO OPERATE SAID BOOM HYDRAULIC POWER MEANS TO RETRACT SAID BOOM, AND MEANS TO RELEASE SAID HOLDING MEANS BY SAID HYDRAULIC FLUID IN SAID ONE DIRECTION AS THE BOOM IS EXTENDED BY OPERATION OF SAID BOOM HYDRAULIC POWER MEANS, SAID LINE BEING PAID OUT FROM THE WINCH BY A PULLING FORCE ON THELINE AS THE BOOM IS EXTENDED, SAID LINE PULLING FORCE ACTING ON SAID WINCH HYDRAULIC MOTOR TO DRIVE THE MOTOR AS A HYDRAULIC PUMP, A VALVE CONNECTED ACROSS SAID WINCH HYDRAULIC MOTOR AND BEING OPENED IN RESPONSE TO THE PRESSURE OF THE HYDRAULIC FLUID WHEN THE WINCH HYDRAULIC MOTOR IS DRIVEN AS A PUMP FOR FLOW OF HYDRAULIC FLUID THROUGH THE MOTOR AND THE VALVE.