US3592346A

US3592346A - Winching with greater speed downwardly

Info

Publication number: US3592346A
Application number: US741048A
Authority: US
Inventors: Wilburn Kelly Brown
Original assignee: Pettibone Corp
Current assignee: Pettibone Corp
Priority date: 1968-06-28
Filing date: 1968-06-28
Publication date: 1971-07-13
Anticipated expiration: 1988-07-13

Abstract

In a hydraulic crane in which the line or winch speed is usually limited by the output of a positive displacement hydraulic pump, a faster speed downwardly is provided by a valve (preferably foot controlled) which will add to the normal flow in the ''''down'''' hydraulic conduit additional fluid from a supplemental source of supply which may be one not always available. The hydraulic fluid provided for another function of the crane, e.g. from a slewing pump, can be used. A check valve prevents reverse flow from the ''''down'''' conduit.

Description

United States Patent [72] inventor Wilburn Kelly Brown Morton Grove, Ill.

[21] Appl. No. 741,048

[22] Filed June 28, 1968 [45] Patented July 13, 1971 [73] Assignee Pettibone Corporation Chicago, Ill.

[54] WINCHING WITH GREATER SPEED kui ilii sl on ER CV f FUNCTION 3,208,221 9/1965 Schuetz 60/97 (P) 3,312,059 4/1967 Stuteville.. 60/97 (P) 3,390,785 7/1968 Lado 254/186 3,018,902 1/1962 Minty 212/26 3,458,053 7/1969 Reuter 254/172 FOREIGN PATENTS 1,007,428 10/1965 Great Britain i. 254/184 Primary Examiner-Harvey C. Hornsby Attorney-Darbo, Robertson & Vandenburgh ABSTRACT: In a hydraulic crane in which the line or winch speed is usually limited by the output of a positive displacement hydraulic pump, a faster speed downwardly is provided by a valve (preferably foot controlled) which will add to the normal flow in the down" hydraulic conduit additional fluid from a supplemental source of supply which may be one not always available. The hydraulic fluid provided for another function of the crane, eg from a slewing pump, can be used. A check valve prevents reverse flow from the down conduit.

PATENTED JUL 1 3 l97l 3; 592 346 2 OTHER cvi FUNCTlON Inventor wliburn. Kellg Brown.

WINCHING WITH GREATER SPEED DOWNWARDLY BACKGROUND OF THE INVENTION This invention relates to an improvement in the manufacture and function of hydraulic cranes. It is particularly advantageous when used with cranes having long booms requiring payout of long lengths of line. In such cranes the speed with which the line is paid out is usually limited by the output ofa positive displacement hydraulic pump. Excess size in such pumps would be costly, and they accordingly tend to be chosen of a size which will fully utilize the engine horsepower in raising a maximum load.

It is an object of this invention to provide a crane capable of winching with greater speed downwardly. Another object of this invention is to provide more uniform horsepower utilization comparing that of the crane when winching upwardly and when winching downwardly.

SUMMARY In accordance with this invention a faster winching speed, e.g. downwardly, is provided by an operator-controlled valve which, without appreciable other cost, connects to the winching hydraulic conduit a supplemental source of hydraulic fluid. Typically the supplemental supply is a supply needed anyway for another purpose, even though not always available. This supplemental source of fluid can be the bypass hydraulic fluid from another idle function of the crane, e.g. the slewing mechanism; or it could even be the fluid used in such other function and hence of lower pressure. The presence of a check valve in the supplemental supply line prevents reverse flow from the main down" conduit.

DESIGNATION OF THE FIGURES OF THE DRAWINGS FIG. 1 is a perspective view of a truck-borne hydraulic crane of the type in which this invention is particularly advantageous.

FIG. 2 is a schematic diagram showing a relationship between various mechanical and hydraulic components which is in accordance with this invention.

DESCRIPTION OF PREFERRED EMBODIMENT Although the following disclosure offered for public dissemination in return for the grant of a patent is detailed to ensure adequacy and aid understanding, this is not intended to prejudice that purpose of a patent which is to cover each new inventive concept therein no matter how others may later disguise it by variations in form or additions or further improvements. The claims at the end hereof are intended as the chief aid toward this purpose; as it is these that meet the requirement of pointing out the parts, improvements, or combinations in which the inventive concepts are found.

FIG. 1 illustrates a truck-borne crane having a telescoping boom 11 in which the hydraulically controlled

sections

13 and 14 telescope in and out of the bottom boom section 12. When the boom is in its fully extended condition, the loadsecuring device such as the hook 16 may be required to travel repeatedly from a considerable height.

FIG. 2 is a schematic diagram showing various mechanical and hydraulic components involved in the paying out and reeling in of the winch line in accordance with this invention. Conventionally hydraulic fluid from reservoir 20 is supplied at high pressure by a positive displacement pump 21 to valve mechanism 22 which is manually operated by handle 23. Unless otherwise indicated the valves and pumps referred to in the schematic diagram are entirely conventional and the details of their construction will hot be discussed at length herein. In normal operation when handle 23 is in a position which permits no passage of hydraulic fluid to or from hydraulic motor 24 the high-pressure fluid is returned to reservoir 20 in return conduit 25. When valve handle 23 is in the position which causes the up movement of hook 16 the high-pressure hydraulic fluid goes to hydraulic motor 24 by way of up conduit 26 and is returned from hydraulic motor 24 by way of down" conduit 27. Returning hydraulic fluid goes through valve 22 and return conduit 25 to reservoir 20. When control handle 23 is in the position which causes the down" movement of hook l6, high-pressure fluid from pump 21 goes through down conduit 27 to hydraulic motor 24 and returns to the valve through up" conduit 26 and to the reservoir 20 by way of return conduit 25. A pilotactuated check valve 28 in the line 26 prevents discharge from motor 24 in the loadlowering direction unless it receives a predetermined pilot" pressure from line 27, such as 400 pounds.

Operation of hydraulic motor 24 rotates worm gear 30 and worm wheel 31 meshed therewith. Worm wheel 31 is fixed to shaft 32 which is carried by bearing means 33. Fixed onshaft 32 is winch reel 34 which in turn carries the line or cable 15. Hence when the handle 23 is in the up position the motor 24 is driven in such a direction that the reel 34 reels-in cable 15. The opposite is true when handle 23 is in the down position.

Other functions of the crane such as boom extension, slewing motion, i.e. side-to-side swing of the boom, and boom elevation and lowering are hydraulically powered by hydraulic fluid passing from reservoir 20 through conduit 40, pump 41, conduit 40 and valve 42. Each such other function may be controlled by a hydraulic motor 46 which may be a rotary motor or a cylinder and piston. Valve 42 is intended to represent either a single valve or a valve bank, controlling one or more other functions of the crane. Valve 42 (or each valve of the bank) is operated by a handle 44. Valve 42 is preferable of the power beyond" type. Hence, when valve 42 is in the off" position the hydraulic fluid is bypassed. When it has passed the last manual valve that may use it, it flows through conduit 43 which heretofore has lead directly to the reservoir 20. When handle 44 is in on position, fluid passes to a hydraulic motor (not shown) and returns through valve 42 through a return conduit, perhaps separate from conduit 43, to reservoir 20. In the schematic showing conduit 43, therefore, represents any conduit returning fluid from valve 42 to the reservoir, whether spent fluid or power-through fluid. Reservoir 20 is shown at two different locations on the schematic diagram. This is a mere schematic convenience, a single tank being contemplated. All pumps are driven by the crane engine, here shown as the truck engine'48 (FIG. 1).

All the components designated by numbers less than 50 in the drawing illustrate components which have been in conventional use. Components designated by the number 50 and numbers greater than 50 are added in order to provide the improvement in accordance with this invention.

In accordance with this invention valve 50 is interposed in the bypass or return conduit 43. Alternative possibilities, less desirable, are for it to interrupt conduit 40 or to be connected with some other low-cost source of hydraulic fluid under pressure, perhaps lower than that available from

pumps

21 and 41. Valve 50 is controlled by an operator-operated control such as foot pedal 51. Valve 50 includes resilient means such as spring 52 for automatically returning the valve setting to its passthrough condition whenever pressure is not applied to foot pedal 51. Hence, when pressure is not applied to foot pedal 51 the fluid in conduit 43 passes freely directly through the valve in its normal passthrough circuit, e.g. to reservoir 20 by way of conduit 43. Because it passes freely, it is then at low pressure. When the operating lever mechanism, e.g. foot pedal 51, is moved the hydraulic fluid in conduit 43 is shunted through conduit 53 to the winch down" conduit 27 which supplies hydraulic fluid to winch motor 24. Connected in conduit 53 is check valve 54 which permits fluid flow into the down" conduit 27, and prevents return of hydraulic fluid from the main down" conduit 27.

Hence, in the operation of the improvement of this invention the amount of hydraulic fluid supplied to hydraulic motor 24 is not limited by the output capacity of pump 21 during the downward winching or line payout functions. When, in accordance with the use of this invention, the foot pedal 51 is depressed during the downward winching or line payout function, additional hydraulic fluid is supplied to the hydraulic motor 24.

When in accordance with a preferred embodiment of this invention, fluid passes from a slewing control valve 42 into conduit 43, particularly when valve 42 is in the of position and the hydraulic fluid passes through the power beyond" or bypass conduit, depression of pedal 51 causes valve 50to divert the returning fluid in conduit 43 into conduit 53. It is apparent that the supplemental fluid is then available to the winch hydraulic circuit. In accordance with this preferred embodiment the pressures which re potentially available from this supplemental source are substantially the same as the fluid pressures which re potentially available to the slewing motor. During down winching the pressure is usually lower, however, because the winch, doing no work at this time, does not develop much back pressure.

In accordance with this invention, part of the potential power available from the other function pumps which are operating even though the other functions are idle is utilized to increase the down speed of the winch line. The engine driving the pumps also has power available at this time because it is not doing the work of pumping against maximum pressure. Hence, my invention utilizes more of the available horsepower when a load is being lowered and the "other functions" are idle. In accordance with my invention this is preferably achieved without providing more pumps than are already present on the crane.

Valve 50 must not be so connected that when it is operated the output of pump 41 would not be protected by a pressure relief valve. Protection unaffected by valve 50 is represented in the drawing by pressure relief valve 55. Such a relief valve is always provided and it is merely necessary to make sure that is discharge is not through valve 50.

In conjunction with the improvement of this invention, an engineer may choose for worm 30 and worm wheel 31 a high ratio and low lead angle which will make it fully self'locking, thus giving even greater safety than does valve 28. When lifting heavier loads seems more important than speed of lift, the increased down speed of this invention may make this choice attractive.

ACHIEVEMENT Whether or not the special option just mentioned is chosen, this invention permits attainment of a faster downs'peed, when deemed safe, with almost no additional expense except that cost of valve 50 and the foot pedal for operating it. In the preferred form, using the positive displacement pump provided for another function, no change is needed in safety features such as the pilot-actuated check valve 28.

I claim:

1. A crane including a raisable, swingable, extensible boom, a load-lifting line hanging from the boom, a hydraulic-motored winch for winding the line, valves with manual levers for controlling, respectively, the raising, swinging and extension ofthe boom and the winding of the winch, an engine, a first relief-valved positive displacement pump means driven by the engine for winding the winch either way at will under control of one of said valves and of a size to substantially utilize the horsepower available from the engine when lifting a load at the maximum pressure permitted by the relief valve; a down conduit for carrying fluid from the winch control valve to the winch motor, a second conduit serving as a return conduit for carrying said fluid back to he valve, a pilot-actuated check valve preventing the return of the fluid in said return line except when subjected to a substantial pilot pressure from the down line; and a second relief-valved positive displacement pump of large capacity having its output controlled by at least one of said valves other than the winch control valve, characterized by:

a foot-operated high-speed-down valve for connecting flow from said second pump to said down line to increase the speed of lowering a load and more nearly utilize the horsepower available from the engine when the lowering of a load results in utilizing the full output of the first pump means at a pressure far below the maximum and at consequently reduced pumping horsepower, the high-speeddown valve being incapable of use for connecting its second pump to said second conduit for raising a load.

2. A boom and winch apparatus for a crane including a movable boom, a load-lifting line hanging from the boom, a hydraulic-motored winch for winding the line, a manual winch control valve, boom control valve means for controlling movement of the boom, an engine, a first relief-valved positive displacement pump means driven by the engine for winding the winch either way at will under control of said winch control valve and of a size appropriate for the horsepower available from the engine when lifting a load at the maximum pressure permitted by the relief valve; a down" conduit for carrying fluid from the winch control valve to the winch motor to drive the winch in a load-lowering direction, a second conduit serving as a return conduit for carrying said fluid back to the valve, a pilot-actuated check valve preventing the return of the fluid in said return conduit except when subjected to a substantial pilot pressure from the down line; and a second relief-valved positive displacement pump of large capacity having its output controlled by said boom control valve means, characterized by:

3. A boom and winch apparatus for a crane including a movable boom, a load-lifting line hanging from the boom, a hydraulic-motored winch for winding the line, a manual winch control valve, boom control valve means for controlling movement of the boom, an engine, a first relief-valved positive displacement pump means driven by the engine for winding the winch either way at will under control of said winch control valve and of a size appropriate for the horsepower available from the engine when lifting a load at the maximum pressure permitted by the relief valve; a down conduit for carrying fluid from the winch control valve to the winch motor to drive the winch in a load-lowering direction, a second conduit serving as a return conduit for carrying said fluid back to the valve, a pilot-actuated check valve preventing the return of the fluid in said return conduit exceptwhen subjected to a substantial pilot pressure from the down line; and a second relief-valved positive displacement pump oflarge capacity having its output controlled by said boom control valve means, characterized by:

an operator-operated high-speed-down valve for connecting flow from said second pump to said down line to increase the speed of lowering a load and more nearly utilize the horsepower available from the engine when the lowering of a load results in utilizing the full output of the first pump means at a pressure far below the maximum and at consequently reduced pumping horsepower, the highspeed-down valve being incapable of use for connecting its second pump to said second conduit for raising a load.

4. A boom and winch apparatus for a crane including a movable boom, a load-lifting line hanging from the boom, a hydraulic-motored winch for winding the line, a manual winch control reversing valve, boom control reversing valve means for controlling movement of the boom, by changes in connections of its controlled ports to fluid supply and return-fromvalve conduits, an engine, a first relief-valved positive displacement pump means driven by the engine for winding the winch either way at will under control of said winch control valve and of a size appropriate for the horsepower available from the engine when lifting a load at the maximum pressure permitted by the relief valve; a down" conduit for carrying fluid from the winch control valve to the winch motor to drive the winch in a load-lowering direction, a second conduit serving as a return conduit for carrying said fluid back to the valve, a pilot-actuated check valve preventing the return of the fluid in said return conduit except when subjected to a substantial pilot pressure from the down line; and a second relief-valved positive displacement pump oflarge capacity having its output controlled by said boom control valve means, characterized by:

an operator-operated high-speed-down valve for connecting necting its second pump to said second conduit for raising a load.

Claims

1. A crane including a raisable, swingable, extensible boom, a load-lifting line hanging from the boom, a hydraulic-motored winch for winding the line, valves with manual levers for controlling, respectively, the raising, swinging and extension of the boom and the winding of the winch, an engine, a first reliefvalved positive displacement pump means driven by the engine for winding the winch either way at will under control of one of said valves and of a size to substantially utilize the horsepower available from the engine when lifting a load at the maximum pressure permitted by the relief valve; a ''''down'''' conduit for carrying fluid from the winch control valve to the winch motor, a second conduit serving as a return conduit for carrying said fluid back to he valve, a pilot-actuated check valve preventing the return of the fluid in said return line except when subjected to a substantial pilot pressure from the down line; and a second relief-valved positive displacement pump of large capacity having its output controlled by at least one of said valves other than the winch control valve, characterized by: a foot-operated high-speed-down valve for connecting flow from said second pump to said down line to increase the speed of lowering a load and more nearly utilize the horsepower available from the engine when the lowering of a load results in utilizing the full output of the first pump means at a pressure far below the maximum and at consequently reduced pumping horsepower, the high-speed-down valve being incapable of use for connecting its second pump to said second conduit for raising a load.

2. A boom and winch apparatus for a crane including a movable boom, a load-lifting line hanging from the boom, a hydraulic-motored winch for winding the line, a manual winch control valve, boom control valve means for controlling movement of the boom, an engine, a first relief-valved positive displacement pump means driven by the engine for winding the winch either way at will under control of said winch control valve and of a size appropriate for the horsepower available from the engine when lifting a load at the maximum pressure permitted by the relief valve; a ''''down'''' conduit for carrying fluid from the winch control valve to the winch motor to drive the winch in a load-lowering direction, a second conduit serving as a return conduit for carrying said fluid back to the valve, a pilot-actuated check valve preventing the return of the fluid in said return conduit except when subjected to a substantial pilot pressure from the down line; and a second relief-valved positive displacement pump of large capacity having its output controlled by said boom control valve means, characterized by: a foot-operated high-speed-down valve for connecting flow from said second pump to said down line to increase the speed of lowering a load and more nearly utilize the horsepower available from the engine when the lowering of a load results in utilizing the full output of the first pump means at a pressure far below the maximum and at consequently reduced pumping horsepower, the high-speed-down valve being incapable of use for connecting its second pump to said second conduit for raising a load.

3. A boom and winch apparatus for a crane including a movable boom, a load-lifting line hanging from the boom, a hydraulic-motored winch for winding the line, a manual winch control valve, boom control valve means for controlling movement of the boom, an engine, a first relief-valved positive displacement pump means driven by the engine for winding the winch either way at will under control of said winch control valve and of a size appropriate for the horsepower available from the engine when lifting a load at the maximum pressure permitted by the relief vaLve; a ''''down'''' conduit for carrying fluid from the winch control valve to the winch motor to drive the winch in a load-lowering direction, a second conduit serving as a return conduit for carrying said fluid back to the valve, a pilot-actuated check valve preventing the return of the fluid in said return conduit except when subjected to a substantial pilot pressure from the down line; and a second relief-valved positive displacement pump of large capacity having its output controlled by said boom control valve means, characterized by: an operator-operated high-speed-down valve for connecting flow from said second pump to said down line to increase the speed of lowering a load and more nearly utilize the horsepower available from the engine when the lowering of a load results in utilizing the full output of the first pump means at a pressure far below the maximum and at consequently reduced pumping horsepower, the high-speed-down valve being incapable of use for connecting its second pump to said second conduit for raising a load.

4. A boom and winch apparatus for a crane including a movable boom, a load-lifting line hanging from the boom, a hydraulic-motored winch for winding the line, a manual winch control reversing valve, boom control reversing valve means for controlling movement of the boom, by changes in connections of its controlled ports to fluid supply and return-from-valve conduits, an engine, a first relief-valved positive displacement pump means driven by the engine for winding the winch either way at will under control of said winch control valve and of a size appropriate for the horsepower available from the engine when lifting a load at the maximum pressure permitted by the relief valve; a ''''down'''' conduit for carrying fluid from the winch control valve to the winch motor to drive the winch in a load-lowering direction, a second conduit serving as a return conduit for carrying said fluid back to the valve, a pilot-actuated check valve preventing the return of the fluid in said return conduit except when subjected to a substantial pilot pressure from the down line; and a second relief-valved positive displacement pump of large capacity having its output controlled by said boom control valve means, characterized by: an operator-operated high-speed-down valve for connecting flow from said return-from-valve conduit to supply fluid therein derived from the second pump to said down line to increase the speed of lowering a load and more nearly utilize the horsepower available from the engine when the lowering of a load results in utilizing the full output of the first pump means at a pressure far below the maximum and at consequently reduced pumping horsepower, the high-speed-down valve being incapable of use for connecting its second pump to said second conduit for raising a load.