US3399868A

US3399868A - Rope pay-out apparatus

Info

Publication number: US3399868A
Application number: US627552A
Authority: US
Inventors: Karl E Reischl
Original assignee: Bucyrus Erie Co
Current assignee: NORTHWEST ENGINEERING Co A CORP OF
Priority date: 1967-03-31
Filing date: 1967-03-31
Publication date: 1968-09-03
Anticipated expiration: 1985-09-03

Description

p 1968 K- E. REISCHL 3,399,868

ROPE PAY-OUT APPARATUS Filed March 51, 1967 INVENTOR KARL E. REISCHL ATTORNEY United States Patent 3,399,868 ROPE PAY-OUT APPARATUS Karl E. Reischl, South Milwaukee, Wis, assignor to Bucyrus-Erie Company, South Milwaukee, Wis., a corporation of Delaware Filed Mar. 31, 1967, Ser. No. 627,552 8 Claims. (Cl. 254-1753) ABSTRACT OF THE DISCLOSURE A cable drum is connected through a gear train containing a sprag clutch to drive an hydraulic pump when it pays out cable. The cable passes over a sheave and is held against the sheave by a roller under pressure from an hy'draulic cylinder. A gear with sloping friction surfaces is gear driven from an hydraulic motor and the friction surfaces are held in driving engagement with the groove of the sheave by another hydraulic cylinder. The hydraulic pump energizes both hydraulic cylinders and the rotary hydraulic motor to pull the cable from the drum during pay out.

Background of the invention An hydraulic crane for oceanographic uses, such as retrieving research submarines, must have a cable sufficiently heavy to sustain heavy loads; but the hook at the end of the cable must be as light as possible to minimize the danger of injury to divers or damage to water craft. When the power winch for the cable is mounted at or near the foot of the boom of the crane, the weight of the hook and length of cable hanging from the boom is insufficient to pull the cable away from the Winch when it pays out the cable. Hence, a positive pay out for the cable is needed; and since the speed of pay out may have to respond accurately from speeds of zero feet per minute to three hundred feet per minute, the response of the rope pay out must be precise. Finally, the positive pay-out apparatus must not impose a load on the cable or winch when the winch is winding in cable, and its weight, cost and complexity must be minimized.

The present invention solves those problems effectively and efficiently. Since such a rope pay out will have utility in many other devices in addition to oceanographic cranes, the invention is not to be considered as limited to oceanographic cranes. For example, in the prior art, positive rope pay-out devices have been used with log skidders, US. Patent No. 2,141,469, and with traveling cranes, US. Patent No. 2,359,073, where the cable winch has a stationary mounting and the cable is carried horizontally by a. carriage supported on cables or beams. However, those devices cannot achieve the precision operation of the present invention, nor do they provide for release of the cable when pay out ceases; but to the extent that the prior art approached such results, the weight, cost and complexity of the gear required was prohibitive.

Summary of the invention The present invention resides in the combination of a power-driven cable drum and a cable sheave remote from the drum, along with a fluid pump which is driven by said drum when said drum pays out cable, a rotary fluid motor which is driven by fluid from said pump, and a linear fluid actuator which is also driven by fluid from said pump and which acts to move said rotary fluid motor into driving relationship with said sheave.

Brief description of the drawings FIG. 1 is a side elevation of an embodiment of the present invention in a crane having a jib pivotally mounted on it.

ice

FIG. 2 is a top view partially in section of the sheave and sheave drive mechanism taken along the line 22 in FIG. 1.

FIG. 3 is a schematic representation of the hydraulic circuitry of the embodiment of the invention shown in FIG. 1.

FIG. 4 is a rear elevation of a portion of the apparatus shown in FIG. 1 illustrating the drive for the hydraulic pump.

Description of the preferred embodiment FIG. 1 illustrates an embodiment of the present invention on a crane similar to the oceanographic crane disclosed in my co-pending application entitled Crane Jib, Ser. No. 628,934 filed on Apr. 6, 1967. The only parts of the crane structure shown in FIG. 1 are those that relate directly to the present invention, and they include aboom 1 and a main jib 2, which is suspended from a pivotal mounting 3 on the underside of the boom 1. Further detail of the structure of this crane can be obtained by reference to the above-mentioned co-pending application. Suffice it for the purposes of this application to show a foot end 4 of the boom 1 with a main cable drum 5 mounted on top of the foot end 4 of the boom 1. The main cable drum is 5 power driven by hydraulic motors (not shown), it has a main Working cable 6 Wound upon it. The cable 6 extends from the cable drum to a sheave 7 which is pivotally mounted coaxial with the pivotal mounting 3 of the main jib 2. After passing over the sheave 7, the main working cable 6 passes down between a pair of pulleys (not shown) at the opposite end of the main jib 2 (not shown), and it has a light Weight hook (not shown) on its opposite end for lifting objects such as small vessels, or submarines used in oceanographic exploration.

The sheave 7 is shown (in section in FIG. 2) pivotally mounted about a shaft 8, which is concentric with the pivotal mounting 3 of the main jib 2. On one side of the sheave 7 there is a friction drive and gear wheel 9 that has row of teeth 10 about the center of its circumference and tapered frictional drive surfaces 11 and 12 on each side of the teeth 10. The tapered friction drive surfaces 11 and 12 engage opposite walls 13 and 14 of a cable groove 15 formed in the center of the circumference of the sheave 7. On the other side of the sheave 7, a freely rotatable grooved roller 16 bears against the cable 6 in the bottom of the cable groove 15 of the sheave 7 to hold the cable 6 in frictional driving engagement with the sheave 7. The teeth 10 of the gear wheel 9 are drivingly engaged by a pinion 17; and when the pinion 17 drives the gear wheel 9, the frictional drive surfaces 11 and 12 on the gear wheel 9 engaging the walls 13 and 14 of the cable groove 15 of the sheave 7 rotate the sheave 7. The grooved roller 16 holds the cable 6 against the cable groove 15 of the rotating sheave 7, and thus the cable 6 is driven, or positively paid out, by the sheave 7.

The main cable drum 5 on the foot end 4 of the boom 1 is coupled through a gear train 18 to drive a fluid pump 19, which in this embodiment is preferably a vane-type hydraulic pump, or an axial piston hydraulic pump. The gear train 18, which couples the cable drum 5 to the fluid pump, 19, is made up of a gear wheel 20 that is mounted to rotate with the cable drum 5, and a pinion 21 that is drivingly engaged by the gear wheel 20 and mounted on a common shaft 22 with the second gear wheel 23. To complete the gear train 18, the gear wheel 23 engages a gear wheel 24 that drives the drive shaft 25 of the fluid pump 19. FIG. 4 illustrates a portion of the pinion 21, common shaft 22, and gear wheel 23 on the common shaft 22, and the gear wheel 24 on the drive shaft 25, and it shows the gear wheel 24 fastened to the driving element 26 of a sprag clutch 27, so that a driven element 28 of the sprag clutch 27 can be mounted on the drive shaft of the fluid pump 19. Thus, the gear train 18 serves two functions: first, the one-way clutch 27 allows the cable drum 5 to drive the pump 19 only when the cable drum 5 is paying out cable 6; and secondly, it gears up the rotational drive speed from the main cable drum 5 to ensure that the fluid pump 19 will be driven at an efficient speed even when the cable drum 5 is paying out cable 6 at the slowest possible rate.

The fluid pump 19 is connected through fluid circuitry 29 to a rotary fluid motor 30 and two

linear fluid motors

31 and 32, which are mounted on the end of the main jib 2. The

linear fluid motors

31 and 32, which are single action hydraulic cylinders, are end mounted on brackets 33 and 34 on opposite sides of the main jib 2. A pair of

arms

35 and 36 are pivotally mounted at one end about a pin 37 on the main jib 2 just beneath the sheave 7. The arm 35 on the left of the drawing, opposite its pivotally mounted end, has a free, forked end 38, in which the groove roller 16 is rotatably mounted, and the linear motor 31 has its piston rod 39 fastened to act upon the forked end 38 of the arm 35. The other linear motor 32 on the opposite side of the main jib 2 has its piston rod 40 fastened to a forked end 41 opposite from the pivotally mounted end of the arm 36, and the friction drive and gear wheel 9 is mounted in forked end 41 of the arm 36. The forked end 41 of the arm 36 also has projections 42 extending from it, which support the rotary hydraulic motor 30 and a gear train 43 for coupling the pinion 17, and thus the gear wheel 9, to be driven by the rotary motor 30. The gear train 43 includes a gear 44 on the shaft 45 of the rotary motor 30, and a gear 46 with the pinion 17 on a shaft 47 mounted on the projections 42 of the forked end 41 of the arm 36, and the gear 46 is engaged by the drive gear 44 on the motor shaft 45. Each of the

arms

35 and 36 is biased away from the sheave 7 by extension springs 48 and 49, respectively, to hold the drive gear wheel 9 normally out of engagement with the sheave 7 and the grooved roller 16 normally out of engagement with the cable 6 on the sheave 7.

When the cable drum 5 is driven by its drive source to wind in on the cable 6, the sprag clutch 27 prevents rotation of the drum 5 from acting on the fluid pump 19, and therefore the drive gear wheel 9 and the grooved roller 16 are held out of engagement with the sheave 7 and the cable 6, respectively, so that the wind in of the cable 6 is free from any additional drag occasioned by the positive pay-out mechanism. However, when the cable drum 5 is driven to pay out on cable 6, the rotation of the cable drum drives the fluid pump 19 at a speed proportional to the rate of pay out. When the fluid pump 19 is driven, it actuates the rotary hydraulic motor 30 and the linear

hydraulic motors

31 and 32. The

linear motors

31 and 32, respectively, drive the grooved roller 16 into engagement with the cable 6 on the sheave 7 and the drive gear wheel 9 into a frictional driving engagement with the walls 13 and 14 of the cable groove 15 of the sheave 7, and the rotary motor 30 driving the friction drive gear wheel 9 through the gear train 43 causes the sheave 7 to rotate at a speed proportional to the speed of the main cable drum. The ratios of the gear train 18 driving the fluid pump 19 and the gear train 43 driving the friction drive gear wheel 9 are such that the sheave 7 is always driven approximately 5% faster than the main cable drum 5. This feature provides a constant tension in the main cable 6, regardless of the speed of pay out, which is the same as the cable 6 and cable drum 5 would experience if there were a heavy weight on the end of the cable 6.

FIG. 3 illustrates in schematic arrangement the apparatus discussed above in conjunction with the fluid circuitry 29 by which it operates. A suction line 51 connects the suction side of the hydraulic pump 19 with a reservoir 52, and a working line 53 connects the discharge side of the hydraulic pump 19 with the

linear motors

31 and 32 and the pressure side of the rotary motor 30. A return line 54 connects the other side of the rotary motor 30 to the reservoir 52. Hence, the

linear motors

31 and 32 and the rotary motor 30 are connected in parallel to the working line 53. In parallel with the rotary motor 30 joining the working line 53 and the return line 54 is a bleed line 55, which contains, in series, a restricted orifice 56, which in this embodiment is variable and would be a needle valve, and a spring loaded check valve 57, which allows fluid under pressure to flow in one direction only, viz, from the working conduit 53 to the return conduit 54. A check valve 58 is inserted in the suction line 51 inside the reservoir 52 to hold fluid in the suction line 51 when the pump 19 is not operating. A relief line 59 containing a pressure relief valve 60 connects the working line 53, adjacent the pump 19 to the reservoir 52. Finally, a drain line 61 from the rotary motor 30 empties into the reservoir 52.

When the hydraulic pump 19 is driven by the cable drum 5 as it pays out cable 6, hydraulic fluid is pumped from the reservoir 52 through the suction line 51 and the hydraulic pump 19 to the main working line 53. This hydraulic fluid under pressure simultaneously actuates the two

linear motors

31 and 32 and the rotary motor 30, with the portion of the fluid that actuates the rotary motor 30 returning to the reservoir 52 through the return line 54. When the rope pay out is stopped and the pump 19 ceases to pump fluid, a slight relaxation in fluid pressure is achieved through the spring loaded check valve 57 and the restricted orifice 56 in the bleed line as the return springs 48 and 49 draw the grooved roller 16 and the friction drive gear wheel 9, respectively, away from the sheave 7, forcing the piston rods 39 and 40 into their

hydraulic motors

31 and 32, respectively. However, the springloaded check valve 57 closes as soon as the fluid pressure drops below the spring loading to maintain the fluid in the main working line 53 so that the next time the main cable drum 5 begins to pay out cable 6, the rope pay out apparatus will respond instantly with the first energization of the pump 19. Also the check valve 58 in the reservoir maintains fluid in the suction line 51 to provide immediate supply to the pump 19. By contrast, if the fluid were allowed to drain out of the main working line 53 or the suction line 51 when the pump 19 is not operating, a substantial delay could result when rope pay out is again started while the pump 19 would refill the working conduit 53 and build up suflicient pressure to drive the

motors

30, 31 and 32. During that delay, the cable 5 could become fouled.

The restricted orifice 56 in the bleed line 55 will allow a continuous discharge of hydraulic fluid from the working conduit 53 to the return conduit 54, but the volume of fluid flow through that restricted orifice 56 is so minuscule as to have no adverse effect on the operation of the system. However, the bleed through the restricted orifice 56 is sufiicient to permit the piston rods 39 and 40 of the

linear motors

31 and 32 to be retracted to /2 inch in order to provide the necessary f or 5 inch clearance between the sheave 7 and the friction drive gear wheel 9 and between the cable 6 on the sheave 7 and the grooved roller 16, when the pressure of the fluid is relaxed. The relief valve in the relief line 59 is set to maintain the desired pressure in the working line 53, but to spill over in the event an overload does develop.

Of course, it will be apparent that common substitutions may be made in this embodiment of the invention without departing from the scope of the invention. For example, the

linear motors

31 and 32 in this embodiment are singleacting hydraulic cylinders or rams; but for the short distance of operation employed here, a diaphragm or other type of linear actuator might also be used. The spring return effected by the external biasing springs 48 and 49 might also be achieved with an internal spring inside of the

linear motors

31 and 32, or some other such variation. There are many different types of rotary motors 30,

any one of which could be used if desired. The same is true of the rotary vane pump 19.

In some applications it may also be possible to eliminate the bleed line 55, and allow the fluid from the release of the

linear motors

31 and 32 to bleed through a fractional rotation of the rotary motor 30'. In such an embodiment it may be desirable to insert a light back pressured motor discharge check valve (not shown) in the drain line 54 to prevent a draining developing in the drain line 54 due to oil gravity when the system is deenergized to cause a syphoning of fluid through the motor 30 back to the tank 52. There are, of course, any number of still further substitutions and modifications that could be made to arrive at additional embodiments of this invention, but these need not be catalogued here. The invention, in its full scope, is set forth in the claims that follow.

I claim:

1. A positive cable pay-out apparatus comprising the combination of a drum power driven to wind in and pay out cable;

a sheave rotatably mounted remote from said drum to receive said cable on it;

a coupling means connecting said power-driven drum to said fluid pump to drive said fluid pump when said drum pays out said cable;

a rotary motor driven by fluid from said fluid pump;

a sheave drive means connected to be driven by said rotary motor to rotate said sheave and adapted to be placed in and out of driving engagement with said sheave;

a linear motor means driven by fluid from said fluid pump, and mounted to automatically place said sheave drive means into driving engagement with said sheave;

and fluid circuitry including a reservoir and interconnecting said reservoir, said pump, said rotary motor and said linear motor.

2. A positive cable pay-out apparatus as set forth in claim 1 including means for holding said cable in frictional driving engagement with said sheave only when said rotary motor is driven by fluid from said pump.

3'. A positive cable pay-out apparatus as set forth in claim 2 wherein said means for holding said cable in frictional driving engagement with said sheave includes a grooved roller movably mounted to engage said cable on said sheave and connected to said linear motor means to be moved thereby into engagement with said cable on said sheave only when said rotary motor is driven by fluid from said pump.

4. A positive cable pay-out apparatus as set forth in claim 1 wherein said fluid circuitry includes a conduit connecting said reservoir to said fluid pump, a second conduit connecting said pump to said rotary motor and said linear motor means and a third conduit connecting said rotary motor and said linear motor means to said reservoir;

said linear motor means and said rotary motor are connected in parallel across said second and said third conduits;

and a bleed line having a restricted orifice and spring loaded check valve permitting flow of an amount of fluid only sufficient to relax fluid pressure when rope pay out ceases is connected across said second and third conduits.

5. A positive cable pay-out apparatus as set forth in claim 4 wherein a check valve is mounted in said second conduit between said fluid pump and both said pilot line and said linear and rotary motors permitting fluid flow from said pump to said linear and rotary motors;

a check valve is mounted in said pilot line permitting fluid flow from said second conduit to said third conduit;

said second conduit is connected to said reservoir through a pressure relief valve;

and a drain line is connected from said rotary motor to said reservoir.

6. A positive cable pay-out apparatus as set forth in claim 1 wherein said coupling connecting said power-driven drum to said fluid pump is a gear train including a one-way clutch to transmit force only when said power-driven drum pays out said cable. 7, A positive cable pay-out apparatus as set forth in claim 1 wherein said sheave drive means includes a movably mounted gear wheel connected by a gear train to be driven by said rotary motor, and said gear wheel has friction surfaces engageable with the groove of said sheave to drive said sheave and is normally spring biased out of engagement with said sheave groove; and said linear motor means includes a single action hydraulic cylinder connected to said movably mounted gear wheel to force said gear wheel into friction driving engagement with said sheave groove when said fluid pump is driven. 8. A positive cable pay-out apparatus as set forth in claim 1 wherein said apparatus is mounted on a crane having a boom, a jib pivotally suspended from said boom, and a cable for lifting loads on said jib and extending from a free end of said jib to a foot of said boom;

r said power-driven drum is mounted on said foot of said 4 boom;

and said sheave is mounted coaxial with the pivotal suspension of said jib from said boom.

References Cited UNITED STATES PATENTS 2,279,853 4/1942 White 254175.7 2,283,321 5/1942 Doe 53 2,436,510 2/1948 Ferguson 254-1391 3,005,622 10/1961 Garnier 254 17s.7

FOREIGN PATENTS 1,203,759 1/1960 France.

60 RICHARD E. AEGERTER, Primary Examiner.

H. C. HORNSBY, Assistant Examiner.