US3503646A - Self-adjusting hoist sling - Google Patents

Description

March 31, 1970 J. 1... SOLOMON SELF-ADJUSTING HOIST SLING 5 Sheets-Sheet 5 Filed March 8, 1968 lI-IG. 7

IFIG. 6

United States Patent 3,503,646 SELF-ADJUSTING HOIST SLIN G Joseph L. Solomon, 194 Buckminster Road, Brookline, Mass. 02146 Filed Mar. 8, 1968, Ser. No. 711,684 Int. Cl. B66c N18 US. Cl. 29474 4 Claims ABSTRACT OF THE DISCLOSURE A sling is described which is usable with a hoist and which is self-adjusting with load and self-sustaining without load. The sling comprises a pair of wire ropes and a pair of retainer members, each having a connection and a passage. Each rope passes through one retainer member and is pivotally connected to the other so as to form a double sling. The retainer members have both inner and outer retaining surfaces, with the ropes being in frictional contact with the outer surfaces where there is no load.

BACKGROUND OF INVENTION This invention relates to slings and similar means for use with hoists in moving large and heavy objects, as for example, are classified in Class 294 Handling, Hand and Hoist-Line Implements, Subclasses 74 Hoist-Line Slings and 86 Grapples.

Hoist slings that have been previously described for large, heavy and bulky objects have generally been restricted in application and are only useful for a particular size object. Further, prior art slings are usually in a collapsed state when there is no load and, in addition, require difficult and tedious adjustment to insure that the sling is properly wrapped around the object to be handled. One object of the present invention is to provide a sling suitable for a hoist which can be used for a variety of different sized objects, is substantially self-adjusting and is self-sustaining when there is no load. Other objects and advantages of this invention will be apparent from. the description and claims that follow taken together with the appended drawings.

SUMMARY OF INVENTION The hoist of this invention comprises a pair of wire ropes or cables of sufficient length so as to be able to form two loops around the object in question. Each rope is adapted to be connected at one end to a hoist .or other lifting or suspending means. The other end of each rope is pivotally connected to a different one of two retainer or guide members. Each of these retainer members has an opening, typically curved, through which the other rope passes so that the two ropes and two retainer members form a sling with two loops. Means are provided so as to place the rope in frictional contact with the member when there is no load. One such means is provided by having the opening of each of the retainer members comprise an outer retaining surface wherein the rope passing through is in frictional contact with the outer surface when there is no load. The opening is preferably curved and tubular and covers an arc of about one-fourth of a circle. The device is thus self-adjusting with load and selfsustaining without load.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a perspective view of one embodiment of the invention showing the sling engaging a crate.

FIG. 2 is a median section along line 2--2 through the retaining and guiding member 33, with the load as shown in FIG. 1.

FIG. 3 illustrates the same sling as in FIG. 1 hanging without a load.

FIG. 4 is a median section along line 4-4 through retaining and guiding member 33 as shown with no load in FIG. 3.

FIG. 5 is a side elevation of retaining and guiding member 33 showing connection to the end of wire cable 16.

FIG. 6 is an end view along line 6-6 of FIG. 5.

FIG. 7 is a partial sectional view along line 77 of FIG. 5.

SPECIFIC EXAMPLE OF INVENTION As illustrated in the drawings, the sling of this invention comprises two lengths of cable 16 and 31. The ends 15 and 30 of these cables are attached by rings to a ring 12 which is carried on a hook '14 of a hoisting cable. Cable 31 extends through the tubular passageway 37 in retaining and guiding member 33 where it bends and then extends around one end of crate 19 and then terminates in a yoke 40 pivotally mounted on a pin extending through retaining and guiding member 18. Cable 16 extends through the curved tubular passage of retaining and guiding member 18 where its bent end extends around the other end of crate 19, terminating in yoke 25 pivotally attached by pin 36 to retaining and guiding member 33.

The retaining and guiding members 33 and 18 are of identical construction and are illustrated with reference to member 33. The member is made up of a curved outer channel portion 37a, a curved inner channel portion 38b with side plates 34 and 35. As shown in FIGS. 6 and 7, the two channels and the resulting passageway 37 are formed by an outer U-shaped member and an inner bar member 38 which are held together with the yoke 25 by means of pin 36 extending through the corresponding orifices 34a, 38a and 35a. Bar member 38 has upper indentations 38c and 38d matching complementary protrusions and side plates 34 and 35 to prevent rotation of the bar 38 with respect to the outer member 33. Pin 36 is held in position by a cotter pin 36b.

The yoke 25 as illustrated in the drawings is essentially an open swage socket with the socket portion receiving the end of cable 16. The yoke arms 26 and 27 have orifices 26a and 27a for cooperation with the retaining and pivot pin 36.

Having reference in particular to FIGS. 2 and 4, the retaining and guiding member 33 in assembled form has a tubular passageway with an outer surface channel 37a and an inner surface 38b, each of which are approximately one-quarter of the arc of a circle in extent. Under load condition as illustrated in FIG. 2, the cable 31b is in frictional contact with the inner surface 38b after the cables have adjusted themselves to the load 19. In this condition, the cable does not come in contact with the outer surface 37a. However, when there is no load, as illustrated in FIG. 4, the cable 31a makes frictional contact at each end with the adjacent portions 37b and 370 of the outer surface 37a. By virtue of the relative stiffness of wire rope or cable and the high friction resulting from metal to metal contact, this condition permits the selfsustaining position as illustrated in FIG. 3 of a sling of this invention without any load.

I claim:

1. A sling characterized as being self-adjusting with load and self-sustaining without load, comprising in combination: two wire ropes and two retaining and guiding members; each said ropes being adapted to be connected at one end to a lifting or suspending means and to be pivotally connected at the other end to a different one of said members; each said member having an opening through which the other wire rope extends so that the ropes and members form two loops; said opening comprising a curved, tubular passageway having an outer, retaining surface and an inner guiding surface; said rope and passageway being so constructed that said rope is automatically in frictional contact with said outer retaining surface when there is no load.

2. The sling as defined by claim 1 wherein said inner and outer surfaces approximate the extent of the arc of one-fourth of a circle.

3. The sling as defined by claim 1 wherein a said member comprises an outer U-shaped member and an inner bar member held together in nonrotative combination to form a tubular passageway.

4. The sling as defined by claim 3 wherein the pivotally connected end of the rope is mounted on a yoke whose 7/1912 Ramey 294-74 1/1932 McConnell 294--74 X 0 GERALD M. FORLENZA, Primary Examiner GEORGE F. ABRAHAM, Assistant Examiner US. Cl. X.R.

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