US3259421A - Hoisting grapple - Google Patents

Description

July 5, 1966 c. w. DAVIS ETAL HOI STING GRAPPLE Filed Dec. 13, 1965 Charles W. Davis Willia 5 Brooks INVENTORS ATTORNEY United States Patent 3,259,421 HOISTING GRAPPLE Charles W. Davis, Huntsville, and William B. Brooks,

Guntersville, Ala, assignors to Thiokol Chemical Corporation, Bristol, Pa., a corporation of Delaware Filed Dec. 13, 1963, Ser. No. 330,375 1 Claim. (Cl. 294-93) This invention relates to handling devices and, more particularly, to a hoisting grapple adapted to the handling of apertured shells.

In the handling of light-weight pressure vessels and their component parts, rocket engines, nozzles and the like, care must be take-nthat grapple means used does not damage the object being handled. Additionally, the grapple means should be simple and easy to use.

Known-art devices, such as the common triple-hook chain sling, tongs, clamps, and the like, can very easily damage the light, thin-walled metal and plastic components which have found increasing use in the missile field, for example. Magnetic devices can obviously be used only on magnetic materials, and even then their use is frequently objectionable because of residual magnetism induced by their use. Harnesses and frame Works of relative complexity have been used, but their installation and removal require inordinate amounts of time.

It is accordingly an object of the present invention to provide a simple hoisting grapple particularly adapted to the handling, without damage, of apertured shells.

It is a further object of the present invention to provide a hoisting grapple which can be rapidly attached and removed without the use of tools.

The objects of the present invention may generally be obtained through the use of a grapple means comprising three equal-size wedging masses tethered by equal-length tethering means to a single fulcrum means. In its simplest form the grapple means comprises three equalsize balls tethered to a hoisting ring by equal-length cables.

The single figure depicts, in a partially sectioned perspective view, one embodiment of the present invention being used to hoist a section of missile casing.

In the figure, 1 is a section of missile casing, consisting of a truncated conical shell 2 having its smaller open end 3 uppermost. The hoisting grapple 4 of the present invention comprises -a hoisting ring 5, three equal- size spheroids 6a, 6b and 6c and three equal- length tethering lines 7a, 7b and 70, being hidden from view, tethering the spheroids 6a, 6b and 60 to the hoisting ring 5. A hookter-minated hoisting line 8 connects the hoisting grapple 4 by means of the hoisting ring to a known-art hoisting engine (not shown).

To lift the casing section 1, the hoisting grapple 4 is lowered onto the section 1 and the spheroids 6a, 6b and 6c inserted, one at a time, into the opening 3. With all these spheroids inside the casing section, the slack in the hoisting line 8 is taken up. Because the spheroids 6a, 6b and 6c are suspended by equal- length tethering cables 7a, 7b and 7c, all three are lifted simultaneously toward the opening 3. but, because of interference with one another, become wedged below the opening 3. After the casing "ice section has been transferred to its new location, the hoisting line 8 is slacked off and the spheroids 6a, 6b and 60 extracted, one at a time, by means of the tethering cables 7a, 7b and 7c.

The wedging masses are not restricted to a spheroidal shape, but may be in the form of hemi-spheres, spherical segments, cylindrical sections or truncated conical sections. The only critical feature is the size of each mass in relation to the size of the opening through which it is to be passed. The size must be such that one wedging mass and two tethering means can be simultaneously passed through the opening, but three wedging masses can not be simultaneously passed through the same openmg.

In the specific case of spheroidal wedging masses, their diameter may be from 55 to percent of the diameter of a circular opening. For openings of other configurations, the dimensions of the wedging masses will be determined from the diameter of a circle circumscribed about the opening.

The wedging masses may be made of any suitable material, the choice being determined by the size and material of construction of the object to be lifted. Elastomeric materials of limited deformation, such as natural and synthetic rubbers and similar plastics are suitable for most uses where freedom fro-m damage is essential. Wood and various metals, which may optionally be coated with a resilient coating, are also useful. The tethering means may be rope, wire cable, chain or the like, optionally covered with a resilient coating or sheath.

While the present invention has been described by means of specific example and in a specific embodiment, it should not be limited thereto, for obvious modifications will occur to those skilled in the art without departing from the spirit of the invention or the scope of the subjoined claim.

What is claimed is:

A. hoisting grapple comprising a fulcrum hoisting ring,-

three equal-length flexible cables, having one end of each cable looped through said hoisting ring so that each of said one ends will lie in a plane in diametrically-opposed parallel relation to their respective cable, three equal-size spheroids formed of an elastomeric material, one of said spheroids connected to the opposite end of each of said cables and a clamp engaging the said one end of each cable and that portion of the cable that is in diametrically opposed relation to the said one end of the cable to detachably tether said cable to said hoisting ring.

References Cited by the Examiner UNITED STATES PATENTS 2,848,269 8/1958 Havens 29486 X FOREIGN PATENTS 585,963 10/1959 Canada.

GERALD M. FORLENZA, Primary Examiner.

SAMUEL F. COLEMAN, Examiner.

G. F. ABRAHAM, Assistant Examiner.

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