US2969854A - Lifting, lowering and hauling - Google Patents

Description

3 Sheets-Sheet 1 R BLAIR LIFTING. LOWERING AND HAULING Jan. 31, 1961 Flled May 17, 1957 Jan. 31, 1961 R. BLAIR 2,969,854 LIFTING, LOWERING AND HAULING Filed May 17, 1957 3 Sheets-Sheet 2 Jan- 31, 1961 R. BLAIR 2,969,854

LIFTING, LOWERING AND. HAULiNG Filed May 17, 1957 s Sheets-Shet s United at Pater-it LIFTING, LOWERING AND HAULING Robert Blair, Johannesburg, Transvaal, Union of South Africa, assignor to Anglo American Corporation of South Africa Limited, Transvaal, Union of South Africa Filed May 17, 1957, Ser. No. 659,928

Claims priority, application Union of South Africa May 24, 1956 3 Claims. (Cl. 187-73) This invention relates to the art of lifting, lowering and hauling loads, in which the load is connected by a pair of ropes to a winding drum, which as in a Koepe winder may be a single length wound round the drum, in which case the rope bights are considered herein as two ropes. The invention has predominant, though not exclusive, reference to the hoisting of conveyances in mines and it will be that application which will mainly be discussed herein.

A major problem in the use of several ropes connecting a single drum to a single conveyance is the equalis-ation of the tension in the various ropes. Without such equalisation, a single rope may be called on to sustain the full load with unhappy results.

The main object of the present invention is to overcome this problem. A second object is to minimise the chance of disaster should one of several ropes break in cases Where the ropes are wound over a drum or drums.

According to the invention, in a hoisting system in which a pair of ropes connects the conveyance to the drum, the ends of the ropes are passed around at least part of the periphery of a wheel assembly, in opposite directions, and are secured to the assembly, the load being connected to the assembly about a pivotal axis coincident with the axis of the assembly.

The wheel assembly is preferably a single wheel, but may be two Wheels, one rope being secured to one wheel and the other to the second wheel, each rope passing over both wheels.

Further according to the invention, there is a single wheel with a spiral groove in its periphery.

An embodiment of the invention is illustrated in the accompanying drawings in which:

Figure 1 is a side view,

Figure 2 is a section on the line 2-2 of Figure 1,

Figure 3 is a side view showing the braking means in action,

Figure 4 is a side view of another embodiment,

Figure 5 is a plan view showing the embodiment of Figures 1 to 3 in position in a hoisting system.

In the drawings two ropes, 10, 12 are shown which support a conveyance indicated at 36. The ropes are wound round a drum 139, driven by a motor 140 (see Figure 5). Assuming that the conveyance is guided between spaced vcrtic-al rails 16, differential stretching of the ropes 10, 12 (if they are attached directly to the conveyance) must cause differential tensions in the ropes, since the conveyance cannot tilt to equate the tensions.

According to the invention, the means to equate the tensions in the ropes consists in a compensating wheel 102 that is formed with a circumferential spiral groove 104-. The two ropes are brought down to the centre zone of the wheel and wound around it in the spiral groove 104; and the ends 106 are clamped at 107.

The load, such as the cage 36, is supported by the wheel 102 by structure pivoted about the axis 105 of the wheel. The structure consists in a sheave 206 between the cheeks 108, 109 on which the wheel 102 is mounted.

out to an equal extent. Thus the groove 104- remains fully occupied by rope. However, the ropes could be brought on to the wheel at the sides and be coiledtowards the centre, in which case it would be necessary to leave one or two turns of the spiral empty at each side, to receive rope as the wheel rotates.

In the case of a conveyance such as a mine skip, hoisted by a pair of ropes, if one rope of the pair breaks, the wheel tends to be displaced laterally under the unbalanced tangential force imposed on it by the remaining rope. If the conveyance is guided for vertical movement by means such as the rails 16, and for connection between the wheel and the conveyance is pivotal, the wheel is physically displaced. This displacement is, according to the invention, the wheel to decelerate it smoothly but rapidly so that the remaining rope takes up the increased tension smoothly.

The means illustrated for this end consists in a pair of brake blocks 110, 111 pivotally mounted between the cheeks 108, 109 on cross pins 112, 113 each pair connected by a cruciform linkage 114, the links of which are also mounted on the pins 112, 113. The pins are free of the cheeks.

Each block 110, 111 is connected to an end of a brake band 116, that encircles the wheel periphery.

The ends of the blocks 110, 111 carry rollers 118, 119, and associated with the rollers are stop surfaces 120, 121 on or associated with the conveyance 36, which are normally spaced away from the rollers. If however either rope breaks the wheel 102 is displaced laterally, as is shown in Figure 3. Thereupon one or other of each pair of rollers 118, 119 (depending on which rope is broken) is forced down on to its stop surface 120, 121 and the consequent tilting of the block, acting through the linkage 114, tightens the brake bands 116 around the wheel a1 1d prevents or at the worst slows down the unwinding of the remaining rope from the wheel.

The braking means need not necessarily be mechanical: it may be hydraulic or electrical. But whatever its nature, but for such means if a rope should break the wheel would turn, to pay out the unbroken rope, until complete exhaustion of the rope, when the jar on the rope as the cage is arrested might well cause the rope to break or to be torn from its mooring on the wheel.

When one rope breaks close to the conveyance in a system such as that under discussion, the severed rope, being attached to the winder drum, its weight is not imposed on the conveyance during or after breakage, as is the case with a friction winder. This feature, allied with a braking means on the wheel, greatly enhances the security of the system, so that the factor of safety of the ropes may be materially reduced with consequent saving in prime and operating costs.

In the embodiment illustrated in Figure 4, the wheel assembly comprises two wheels 132 and 133 mounted edge to edge as shown. The Wheels 132, 133 are carried between common cheek plates 138 and excepting that they may be thinner the wheels are the same as the wheel 102 discussed above.

The spacing between the edges of the wheels determines the distance between the ropes and 131. Thus in the embodiment shown the sheaves in the headframe a t J n fil .1251.

made use of to apply a braking force. to

may be fairly close together. The rope 130 is wound round the wheel 132 and its end is secured to the Wheel 133 at 134. Likewise the rope 131 is wound round the wheel 133 and is secured to the wheel 132 at 135.

Both wheels 132 and 133 will rotate sutfi'ciently to take up inequality in the lengths of the ropes at any time.

The wheels 132 and 133 are provided with braking means such as that discussed with reference to Figures 1 to 3, excepting that the Wheel 132 need not have a roller 119 and the wheel 133 a roller 118. As the wheels 133 and 132 are mounted symmetrically about the pivot 136 of the cheeks 138, the cheeks rotate on breaking of a rope 131 or 130 and the relevant roller 119 or 118 comes into operation to brake the Wheel to which the end of the remaining rope is secured.

In the embodiment of Figure 4 the spacing of the ropes and hence of the sheaves is not dependent on the diameters of the Wheels and each may be chosen Without reference to the other.

I claim:

1. A hauling system comprising a winding drum with two separate ropes and a load attached to the ropes, including a compensating device to which the rope ends are attached and which is itself attached to the load, the device consisting in a wheel mounted on a horizontal axis, means to connect the load to the Wheel about a pivotal axis co-incident with the axis of the wheel, in which the rope ends are passed around at least part of the periphery of the wheel in opposite directions, and including braking means associated with the wheel automatically operable on breaking of one rope.

2. The apparatus claimed in claim 1 in which the braking means consists in a brake band around the periphery of the Wheel and means operating automatically to tighten the band on lateral displacement of the wheel due to breaking of a rope.

3. A'hauling system comprising a Winding drum with two separate ropes and a load attached to the ropes, including a compensating device to which the rope ends are attached and which is itself attached to the load; the device consisting in a wheel assembly mounted on a horizontal axis, the rope ends being passed around at least part of the periphery of the assembly in opposite directions; means to connect the load to the assembly about a pivotal axis coincident with the axis of the assembly; braking means consisting in a brake band around the periphery of the assembly; and means operating automatically to tighten the band on lateral displacement of the assembly due to breaking of either one of the ropes.

References Cited in the file of this patent UNITED STATES PATENTS 134,179 Whittier Dec. 24, 1872 1,027,840 Graham May 28, 1912 1,114,180 Pearson Oct. 20, 1914 1,524,198 Morgan 1- Jan. 27, 1925 1,631,340 Rohlfing June 7, 1927 1,641,957 Bledsoe Sept. 13, 1927 1,771,281 Wilsing July 22, 1930 2,590,623 Hulse Mar. 25, 1952 2,752,120 Bogle June 26, 1956

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