US2961216A

US2961216A - Lifting, lowering and hauling and especially in mine hoisting

Info

Publication number: US2961216A
Application number: US590731A
Authority: US
Inventors: Blair Robert
Original assignee: Individual
Current assignee: Individual
Priority date: 1955-06-12
Filing date: 1956-06-11
Publication date: 1960-11-22
Anticipated expiration: 1977-11-22
Also published as: BE548579A

Description

R. BLAIR ,961,

LIFTING. LOWERING AND HAULINIG AND ESPECIALLY IN MINE noxs'rme Nov. 22, 1960 3 Sheets-Sheet 1 Filed June 11. 1956 Nov. 22, 1960 R. BLAIR 2,

LIFTING, LOWERING AND HAULINIG AND ESPECIALLY IN MINE HOISTING Filed June 11, 1956 5 Sheets-Sheet 2 Nov. 22, 1960 R. BLAIR 2,9

LIFTING. LOWERING AND HAULINIG AND ESPECIALLY m MINE HOISTING Filed June 11, 1956 s Sheets-Sheet :5

50 MAI/V sup/ac Y REV.

o o-I United States Patent LIFTING, LOWERING AND HAULING AND ESPECIALLY IN MINE HOISTING Robert Blair, 43 Main St., Johannesburg, Union of South Africa Filed June 11, 1956, Ser. No. 590,731

Claims priority, application Union of South Africa June 12, 1955 4 Claims. (Cl. 254-172) This invention relates to installations in which long lengths of a flexible element such as a rope or cable (referred to herein as a rope) are payed out or wound in at slow speed during the operation of the installation. The primary application of the invention is to mine hoisting and especially to the lowering and raising of stages during shaft-sinking; but the invention is not restricted to such uses.

The usual method of winding the rope in multiple layers on to the drum of a winch has disadvantages, the most significant of which is evident when the rope has to be wound on to the drum under high tension, for it will be appreciated that, when dealing with ropes which may be of the order of 20,000 feet or more in length tensioned to the order of some tons, binding and nipping of the coils in adjacent layers is apt to occur. Furthermore, it is obviously necessary when the rope is delivered from the factory to wind it on to the drum under the required tension, an operation which is not without its inconveniences; and the drum itself and the structure associated with it must be massive enough to withstand the forces imposed on them and must consequently be costly.

The primary object of the present invention is to provide equipment which avoids or minimizes the difiiculties of known procedure.

According to the invention, the equipment consists in a driven wheel around which the rope passes in driving engagement with the wheel, a winch drum on which the rope is wound, a motor to drive the winch at a speed that ensures a rate of pay'in and pay-out at all times exceeding that of the wheel when the winch is in motion, means to form a loop in the rope between the wheel and the winch, and means to maintain the length of the loop between predctermined limits while keeping the tension in the rope of the loop substantially constant.

Further according to the invention, the loop-forming means consists in a jockey pulley suspended freely from the rope, and the means to maintain the loop within its prescribed limits of length are control switches located to be actuated by the pulley (or by structure associated therewith), when the loop attains the limits of its prescribed range of lengths, the switches controlling the motor that drives the winch.

In the operation of the equipment the wheel acts to divide the rope into a zone of high-tension (between it and the load) and a zone of low-tension (between it and the winch). The tensional differential between the zones depends upon the nature of the wheel, the co-efiicient of friction between the rope and the wheel and the angle of contact between the rope and the wheel, and can be selected if not theoretically then empirically so to limit the tension in the low zone that the multi-layer wrapping of the rope around the winch drum is not disadvantageous. Also, since the winch is in the low-tension zone it need not have the robustness of a winch handling highly tensioned rope, its function being merely to pay-out rope as it is demanded by the wheel and wind it in as the wheel surrenders it.

A further aspect of considerable importance is that the tension in the low zone can be so selected that the rope can be wound on to the winch drum under the selected tension at the rope factory, thereby avoiding troublesome and costly rewinding at the place of use.

Thus far the case of a single rope has been discussed. it will be appreciated however, that the invention is equally applicable to a plurality of ropes which are to be synchronously operated, such as occurs in shaft-sinking when stages have to be supported. In fact, as will be shown later, the invention has at least one advantage in these installations which is not present in single-rope installations. In multi-rope installations the wheel is made to receive all the ropes, or several wheels may be gauged, in which case all, or all but one of the wheels, may be provided with clutches; or each wheel may have its own winch and motor.

An embodiment of the invention is illustrated in the accompanying drawings, in which Figure l is a perspective view of hoisting equipment made in accordance with the invention;

Figure 2 is a vertical section through the centre of Figure 1;

Figure 3 is a fragmentary view of a safety braking system, in elevation; and

Fig. 4 is a schematic diagram of the electrical circuit.

The equipment is shown as handling two

ropes

10, 11, but it will be apparent that it could equally well be constructed to deal with fewer or more than two ropes, depending on the nature of the duty which the hoist is to perform.

Each

rope

10 or 11 is fed from a

winch drum

12 or 13, round a direction-changing pulley 14 or 15, down into the cavity 16 of a compensating tower 17, round a

jockey pulley

18 or 19, upwardly towards and over a second direction-changing

pulley

20 or 21, round a driving wheel 22 or 23 and so away to the point of application of the load.

The operations of paying-out and winding-in the ropes are performed by the driving wheels 22, 23. To this end the wheels are driven through suitable drive-transmitting mechanism such as a pinion 24 which meshes with a gearwheel 25 keyed to the shaft 26 of one wheel, and rotated by a motor 26a, the drive to the second wheel being transmitted from the first wheel through a clutch (not shown).

To ensure that there is no significant slip between the ropes and the driving wheel, the ropes are lapped several times around the wheels.

Within the tower 17 the ropes are constrained to form

loops

27 and 28 by the weight of the

jockeys

18 and 19 and the structure associated therewith, which weight may be adjustably varied. These jockeys are guided for vertical movement within the cavity of the tower by pairs of vertical rails 29, 3t) and 31, 32 which areengaged by rollers 33, 34 mounted on the sheaves 35, 36 of the jockeys.

The lengths of the

loops

27 and 28 vary as the

jockeys

18 and 19 move upwardly or downwardly in the tower 17.

The driving wheels 22, 23 divide the ropes into two zones, one, which is that between the wheels and the load being a zone of high tension, the magnitude of which is governed by the load, and the other of which lies between the Wheels 22, 23 and the

winch drums

12, 13

and which is a zone of low tension. The magnitude of.

the rope tension in the low-tension zone is governed by the weights of the

jockeys

13, 19 and remains substantially constant as long as the jockeys are freely suspended from the

loops

27, 28, irrespective of the magnitude, or variations in the magnitude, of the rope tension in the high-tension zone.

If the rates of pay-out and wind-in of one rope are always the same as those of the other rope, the

winch drums

12, 13 may be driven by a single motor 51 housed in a suitable covering 50 with perhaps a clutch on one or either drum to'correct loss of synchronism, but if, as is assumed not to be the case-in the equipment being described, the rates'may vary, then each drum is driven by its own motor.

The drive to the

drums

12, 13 or each of them is so designed that the drum is rotated at a rate that ensures that the wind-in or pay-out of the drum will at all times exceed that of the driving wheels 22, 23.

It follows that when the motor or motors 51 is or are running, the loop of rope 28 or 29 in the compensating tower 17 appropriate 'to'that' motor is always on the increase while rope is being payed out by the

winch

12 or 13, and onthe decrease while it is being wound in. It follows too that themeans'that ke'epsthe length of the

loop

27 or 28; within its prescribed range must be one that arress'tn'e fotatiori' of -the

winch drum

12 or 13 when the limits of'the range are reached. In the embodiment being described the means consist in two

control switches

39, 40 located to be actuated by contact with the chassis 37 or38 on which the

jockey pulley

18 or 19 is mounted, whenever the pulley reaches its upper and its lower limits, the switches being comprised in the circuit of the drum motor or operating a clutch between the motor and the Winch drum.

When the rope is being payed out and the length of the rope in the

loop

27 or 28 is increasing, actuation of the lower switch 40 immobilizes the winch drive whereupon continued lowering of the load on the rope causes the loop to shorten, until the jockey reaches its upper limit and remobili zes the motor. A further quota of rope is then payed out; and so on.

l When a rope is being wound in, the reversal of the drive to the driving wheel 22 or 23 is arranged also to reverse the winch drive and the control switches 39, 44?, so that the reverse operation occurs, the winch drum being stopped when the jockey pulley reaches its upper limit and being started when it reaches its lower limit.

The embodiment may also comprise certain safety devices which come into operation in case of need. These may include

limit switches

41, 42 beyond the

control switches

39, 40, which, should the

jockey pulley

18 or 19 fail to actuate the

control switches

39, 40 or the latter not function, immobilize the entire system. There may also be included a braking device on, associated with, or actuated by, the jockey pulley 1 8 or 19. This device may consist (Fig. 3) in a pair of brake shoes 43, 44 irirespect of each

jockey

18 or 19. Each pair of brake shoes 43, 44 is carried on bell cranks 45, 46, pivotally mounted on a horizontal member 47 of the framework of the tower 17 At rest, the shoes are close to but free from the periphcr es of the

pulleys

15, 21, which may be thickened to provide braking surfaces. The spacing of the shoes from the pulleys is adjustable by screws 48, 49 that make contact with the bell cranks 45, 46.

In use, when the jockey 19 moves above its permitted range, it makes contact with the shoes 43; 44 and jams them between itself and the

pulleys

15, 21. The train of pulleys is thus immobilized, with the ropes kinked around them soto resist further paying out of the ropes that the ropes slip on the driving wheels 22, 23.

The brake device has also a valuable function in a multiple rope installation where one of the ropes breaks. In these circumstances the jockey pulley associated with the broken rope actuates the lower limit switch 41 to bring the system to a stop.

' In Fig. 4, which is a circuit diagram, M1 and M2 represent respectively the motors that drive the

winch

12 or 13 and the driven wheel 22, 23.

There are in fact two motors that drive the

winches

12, 13,0ne for each, but for ease of description, only one and its control means are illustrated and described. The second is merely a duplication of the first.

M1 is fed from a mains supply 50 through a reversing contactor 52. M2 is fed from the mains supply 50 through a circuit breaker 54.

The upper and lower control switches 39, 40 operate to start and stop the motor M1 through the reversing contactor 52. I

Assuming a forward wind of the driven wheels 22, 23 (that is the load is being lowered) the jockey 18 travels upwardly until it comes into contact with the top control switch 39 and closes it to operate the motor circuit 59, 52. This circuit is operated by the

control circuit

58, 39, 40,

directional switch

56, 41, which is closed by the closing of the control switch 39.

Motor M1 is set in motion and pays out rope, allowing the jockey 18 to move downwards. On reaching the bottom control switch 40, it opens the switch to open the control circuit, which in turn opens the motor circuit to stop the motor M1. The jockey then moves upwardly, to close switch 39, to restart the motor, and so on.

On reverse wind (i.e.vthe load ascending) the jockey moves downwardly until it reaches the bottom control switch 40, thereby closing

circuit

58, 42, 39, 40, 56, which in turn operates motor circuit 50, 5-2 to start the motor. Rope is now wound on to the winch drum and lifts the jockey, which ascends to open the top control switch 39 and stop the motor M1. The jockey descends, and so on.

In the event of the control switches failing to operate, the limit switches 42, 41, situated respectively at the top and bottom of the tower 17 are operated by the jockey to open the control circuit and thereby to open the motor circuit to prevent overor underwind.

I claim:

1. Lifting, lowering or hauling equipment comprising a rope, a driven wheel around which the rope passes in driving engagement with the wheel, a motor to drive said wheel, a winch drum on which the rope is wound, a load to which the end of said rope remote from said winch is attached, a motor to drive the winch at a speed that ensures a rate of pay-in and pay-out at all times exceeding that of the wheel when the winch is in motion, a tower located between the wheel and the winch, pulleys arranged to lead the rope into and out of the tower, a jockey pulley freely suspended from the rope within the tower to form a loop of rope between the pulleys, which loop is contained within the tower, switches located to be actuated by structure associated with the jockey pulley, when the loop attains the limits of its prescribed range of lengths, said switches controlling the motor that drives the winch; limit switches beyond said switches arranged to be operated by structure associated with the jockey pulley to stop said driven wheel and winch motors when the loop length moves out of the prescribed range; and braking means to lock the equipment if the length of the loop moves out of the prescribed range, consisting in shoes that are arranged to be jammed between the jockey pulley and pulleys due to shortening of the loop.

2. Lifting, lowering or hauling equipment comprising a rope, a driven wheel around which the rope passes in driving engagement with the wheel, a motor to drive said wheel, a winch drum on which the rope is wound, a load to which the end of said rope remote from said winch is attached, a motor to drive the winch at a speed that ensures a rate of pay-in and pay-out at all times exceeding that of the wheel when the winch is in motion, pulleys including a jockey pulley to form a loop in the rope between the wheel and the winch, and means to maintain the length of the loop between predetermined limits while keeping the tension in the rope of the loop substantially constant; and including also braking means to lock the equipment if the length of the loop moves out of the prescribed range.

3.' Equipment as claimed in claim 2 in which the braking means comprises shoes that are arranged to be between the jockey pulley and pulleys due to shortening of the loop.

4. Lifting, lowering or hauling equipment comprising a rope, a driven wheel around which the rope passes in driving engagement with the wheel, a motor to drive said Wheel, a winch drum on which the rope is wound, a load to which the end of said rope remote from said winch is attached, a motor to drive the winch at a speed that ensures a rate of pay-in and pay-out at all times exceeding that of the wheel when the winch is in motion, a tower located between the wheel and the winch, pulleys arranged to lead the rope into and out of the tower, a jockey pulley freely suspended from the rope within the tower to form a loop of rope between the pulleys, which loop is contained within the tower, control switches located to be actuated by structure associated with the jockey pulley, when the loop attains the limits of its prescribed range of lengths, the switches controlling the motor that drives the winch; limit switches beyond the control switches arranged to be operated by structure associated with the jockey pulley to stop said driven wheel and winch motors when the loop length moves out of the prescribed range; and braking means to lock the equipment if the length of the loop moves out of the prescribed range, consisting in shoes that are arranged to be jammed between the jockey pulley and pulleys due to shortening of the loop.

References Cited in the file of this patent UNITED STATES PATENTS 1,475,855 Murdock Nov. 27, 1923 1,832,430 Siebs Nov. 17, 1931 2,203,946 Doescher June 11, 1940 2,603,428 Newcombe July 15, 1952 2,741,437 Haworth Apr. 10, 1956 2,825,512 Andren Mar. 4, 1958 FOREIGN PATENTS 463,216 Italy Apr. 20, 1951