US2765905A - Lifting and pulling devices and the like - Google Patents

Description

Oct. 9, 1956 w, H. sfANDl-ORD 2,765,905

LIFTING AND PULLING DEVICES AND THE LIKE Filed Deo. 25, 1954 Mmm nited States Patent O LIFI'ING AND PULLING DEVICES AND THE LIKE William Herbert Sandford, London, England, assignor of one-half to Rupert Evelyn Law Warburton, Firmley Green, England Application December 23, 1954, Serial No. 477,186!

Claims priority, application Great Britain January 1, 1954 .2 Claims. (Cl. 20S-399)' This invention provides a portable winch comprising a mounting, at least two spaced drums mounted for rotation in the mounting about parallel axes, said drums being formed with circumferential grooves permitting a rope to be coiled around and between them, said rope having an idle leg and a load sustaining leg, driving means for rotating said drums to draw said rope through said mounting, and a clamping device associating with one of said drums for clamping the idle leg of said rope in one of the grooves in said drum.

In use of such a winch, the rope is wound around the grooves in the drums, which are preferably of V-section, in a figure of eight or other desired formation, with any necessary lateral displacement of the rope as it passes from a groove in one drum to a groove in the other drum. The rope can then be wound continuously, either manually or by a suitable source of power driving the drums. The clamping device serves to press the idle leg of the coiled portion of the rope into its groove to provide an initial grip which is progressively increased by the coiling of the rope around the drums to develop the total grip required. This clamping means may comprise a wheel'or roller operated by suitable mechanism, prefer ably by a rocking arm which also provides a means for attaching the winch to a support or to the load to be moved, so that the clamping device is actuated by any pull on the rope and the clamping pressure is proportionate to the load on the rope.

One embodiment of portable winch according to the invention will now be described in detail, by way of example, with reference to the accompanying drawings, in which:

Fig. 1 is a top plan view of the winch, partly cut away for clarity.

Fig. 2 is a corresponding side view, with the winding handle omitted, and

Fig. 3 is a sectional view through A-A in Fig. l.

Referring to the drawings:

Drums 1A and 1B are rotatably mounted on axis pins 2 carried by a mounting 3. The drums are held in position by shoulders 4 formed on the pins 2, which are threaded to engage the mounting 3 and secured against rotation by grub screws 5. The outer ends 6 of the pins 2 are slightly tapered and engage in holes 7 in a side strap 8, which is hinged to the mounting 3 by a pin 9 at one end and secured at the other end by a removable pin 10. The purpose of the taper on the outer ends 6 of the pins 2 is to permit of side strap 8 being swung open or closed for the purpose of ttting a rope as hereinafter described.

Worm wheels 11 are formed integrally with the drums but, alternatively, could be formed separately and xed thereto. These worm wheels 11 engage and are rotated by a common worm 12 keyed to a spindle 13 carried by the mounting 3. The spindle 13 may be manually rotated as required by a crank arm 14, but alternatively a power unit could be used for the purpose, The worm gearing is preferably self-sustaining. Alternatively, a pawl or 2,765,905 Patented Oct. 9, 1956 ICC brake may be fitted to prevent any possibility of the load rotating the gears. A threaded bush 15 is provided to facilitate entering the spindle 13 which is formed with a shoulder 16 to bear against the bush and retain the spindle and worm in position. A set screw 17 is provided to secure the bush against rotation. It will be apparent that, when the worm 12 is rotated, the drums 1A and 113 will rotate in opposite directions.

The drum 1A has two circumferential V-grooves 18A and 19A and the drum 1B has two substantially similar grooves 18B and 19B. The drums are spaced apart to enable the rope to be coiled thereon in a double figure of eight fashion as hereinafter described.

A pressure roller 20 serves to press the idle leg 30 of the rope into the V-groove 19A and is mounted on a rocking arm 21 by a pin 22. The rocking arm 21 is pivoted to the mounting 3 by a pin 24 extending parallel to the axes of the drums. An extension 23 of the arm carries a threaded stud 25 actuatable by a knob 26` (Fig. l) or by a hexagonal head 26B (Fig. 4) and formed with an end 27 bearing against the mounting at 3A so that rotation ofthe stud 2S will actuate the pressure roller 20 to bring about initial grip on the idle leg of the rope. In Fig. 1 the extension 23 is also provided with an eye 28A or other suitable means of attaching the device and this eye is so positioned that the rocking arm 21 is actuated to apply clamping pressure in response to the load on the load sustaining leg 31 of the rope so that any pull on the attaching eye 28A will increase the clamping pressure proportionately to the pull.

In use of the winch, the eye 28A or 28B is first attached to au anchorage (or to the load to be moved) and the leg 31 of the rope is attached to the load (or to an anchorage) and all slack taken up. The rope is then passed under a fairlead 29 and thence in gure of eight coils partly around the grooves 18B and 18A, thence obliquely to groove 19B, partly around grooves 19B and 19A and finally under the pressure roller 20. Any rotation of the worm 12 will now cause the rope to be drawn through the winch and the load to be lifted or moved. Lowering or slacking off is effected by reversing the direction of rotation of the worm.

Normally an angle of 60 is preferred for the V- grooves 18A and 18B and an angle of 45 for the V- grooves 19A and 19B but these angles may be varied. It will be appreciated that the effective winding diameters of the grooves should correspond to obviate any tendency towards slight internal slip on either of the drums.

What I claim as my invention and desire to secure by Letters Patent is:

l. A portable winch comprising a mounting, at least two spaced drums mounted for rotation in the mounting about parallel axes, said drums being formed with circumferential grooves permitting a rope to be coiled around and between them, said rope having an idle leg and a load sustaining leg, driving means for rotating said drums to draw said rope through said mounting, and an arm pivoted on said mounting and adapted to engage a portion of the idle leg of the rope accommodated in one of said grooves, said arm being formed with attachment means for said winch positioned to rock said arm to apply clamping pressure to said idle leg of the rope in response to the load on the load sustaining leg of the rope.

2. A portable winch comprising a mounting, at least two spaced drums mounted for rotation in the mounting about parallel axes, said drums being formed with grooves,` said arrn being formed Withat't'achment means for said winch positioned to rock said arm and thereby to cause said roller to apply clamping pressure to said 1 idle 4leg of the rope in response to the load on the load sustaining leg of the rope.

References Cited in the file of this patent UNITED STATES PATENTS 402,688 Schulz May 7, 1889 4 OKeefe J une 25, Holub Feb. 25, Roberson v July 21,

FOREIGN PATENTS Great Britain Ian. 1, France Apr. 4,

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