US 2621385 A
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Description (OCR text may contain errors)
Dec. 16, 1952 w J GlLMORE 2,621,385
FITTING FOR WIRE ROPE AND STRANDS Filed Dec. 15. 1947 ATTORNEY Patented Dec. 16, 1952 FITTING FOR WIRE ROPE AND STRANDS William J. Gilmore, Adrian, Mich, assignor to American Chain & Cable Company, Inc., Bridgeport, Conn., a corporation of New York Application December 15, 1947, Serial No. 791,777
1 Claim. 1
This invention relates to fittings for wire rope and strands.
Fittings on ferrous rope or strand are advantageously made in the form of sleeves which are swaged or cold worked onto the rope thus avoiding excessive heat which would damage the rope. However, as a commercial practice, they are very difiicult to apply with the assurance that the hold will be sufiicient if they are subjected to a stress sufiicient to break the rope.
It is therefore a primary object of the present invention to provide a fitting which can be applied on a commercial production basis to develop the full strength of the rope or strand to which it is applied.
Referring now to the drawings:
Fig. 1 is a view showing a cylindrical blank before the first operation thereon;
Fig. 2 shows a similar blank with indentations formed therein as a preliminary step to the fabrication of the fitting, and with a longitudinal hole drilled therethrough;
Fig. 3 is a section taken on line 3-3 of Fig. 2;
Fig. 4 is a view of the fitting after assembly around the strand and after completion of the swaging operation;
Figs. 5, 6 and '7 are sections on lines 5--5, 6-6, and respectively of Fig. 4; and
Fig. 8 is a view of a modified blank used in the practice of this invention.
This invention is described in connection with ferrous strand, for ease of description, and because it is particularly well adapted to strand. It has always been diflicult to grip strand tightly enough, and the failures occur as slippage of the fitting on the wire, rather than as breaking of the wire. However, it is to be understood that the invention is not limited to strand, but can be applied to rope and cable with equal facility.
The example shown is a plain cylindrical fitting, utilized as an ending. As a preliminary step, a solid cylindrical piece of metal l0, preferably with a frustro-conical end II is pressed or punched so as to produce the exterior contour shown in Figs. 2 and 3. This embossing consists of impressing in the cylindrical surface a series of depressions l2 shown as being segments of cylindrical surfaces. It will be noted that they occur in pairs, each succeeding pair being spaced 90 around the periphery of the blank, and all preferably equally spaced from each other. The making of these depressions throws the metal of the blank into a sort of flattened indented shape, as best seen in Figure 3.
After the exterior of the blank has been deformed as above described, a bore I3 is formed therethrough, which may be cylindrical, but preferably has a tapered bell mouth at |4,'the bore being sufficiently large to receive the strand to be secured therein.
A strand [5 is inserted in the bore, and the entire fitting, or at least as much of it as surrounds the strand, is then subject to cold working by swaging, so that it becomes cylindrical. The depressions in the surface are substantially obliterated, and the strand is tightly held by such swaging.
The most important feature of this invention is the arrangement of the depressions and the resultant deformation of the strand under swaging. As shown in Figures 4 to 7 inclusive, the swaging results in a deformation of the strand, by actual displacement of the wires thereof, so that it takes on an oval cross-section directly under each pair of depressions. However, the next adjacent pair of depressions, which is around the periphery of the blank, results in an oval the major axis of which is disposed at right angles to the axis of the first-mentioned oval.
As the wire of which the strand is made is relatively stifi and hard, the deformation is sufiicient to render it impossible to pull the strand out of the fitting. There is considerable friction opposing such withdrawal, but it can be inferred that the development of the full strength of the joint depends upon the rapid change from one oval to another along the axis of the fitting.
This inference is justified by the entire absence of slippage before failure, in testing, as distinguished from swaged fittings without the depressions. This inference is also supported by the fact that the degree of swaging is not overly critical. There is one feature of this invention which is not inherent in the construction, but nevertheless important in the shown structure. As can be seen in Figs. 5 and 6, the material of the sleeve is thickest across the minor axis of the oval. This is as it should be, as the metal is amply strong in tension, and will not rupture in region A as an attempt is made to pull the strand out. Furthermore, the thick Section B cannot bend, which prevents the sleeve from distorting in such a manner as to permit the strand to take a more circular form. Such distortion would, of course, if permitted, tend to result in slippage. This construction is in distinction to sleeves having a uniform thickness around a non-circular strand, which must be made thicker all around to prevent such distortion, and are thus heavier than is theoretically necessary.
Instead of swaging the depressions l2 into the blank, it is perfectly feasible to machine them. As an example, in Fig. 8 a blank I8 is shown with arcuate slots [9 milled across the cylindrical surface, to serve the same function as the deformation practiced in the structure shown in the other views. There are possibly other types of blanks which can be: used, depending on the desired result, and it. is therefore to be understood that the above constructions are illustrative and not limitative, and that the scope of the present invention is to be determined from the appended claim.
An article of manufacture comprising a. ferrous stranded structure and a sleeve compacted thereon, said sleeve having a substantially cylindrical surface, the bore of the sleeve and the portion of the stranded structure therein having oval cross-sections at spaced points along the length, the major axis of the oval cross-section at one point. being. at substantially right. angles,
to the. major axis of the oval cross-section at the other point the transition from one oval cross-section to the other being, in thenature of a widening to a substantially circular cross-section and flattening to the other oval cross-section.
WILLIAM J. GILMORE.
REFERENCES CITED The following references are of record in the file of th'm patent:
UNITED STATES PATENTS Number Name Date 557,037 Toquet Mar. 24, 1896 650,860 McTighe June 5, 1900 650,862 McTighe June 5, 1900 947,601 Schmidmer Jan. 25, 1910 1,711,832 Cooper May 7, 1929 2,008,227 Reilly July 16, 1935 2,109,837 Davis Mar. 1, 1938 2,247,928 Temple July 1, 1941 20 2,276,140 Andren Mar. 10, 1942 FOREIGN PATENTS Number Country Date 528,376 Germany Mar, 25, 1930'