US 3562874 A
Abstract available in
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Description (OCR text may contain errors)
Feb. 16, 1971 J. DIPALMA 3,562,874 v CABLE GRIP Filed Jan. 29, 1969 IIII. y L42,
INVINT() United States Patent O U.S. Cl. 24-123 8 Claims ABSTRACT F THE DISCLOSURE A cable grip having a plurality of wire strands forming a woven tubular cable-receiving sheath and a draft end comprising a bunch of unwoven strands forming a loop. A rigid metal sleeve slidably receives and contains said unwoven strands, and is shaped to form an eye portion and adjacent parallel leg portions from which the Wires emerge. The leg portions of the sleeve are flattened in a plane parallel to the axis of the eye portion into wireclamping engagement with the unwoven wires therein, and the eye portion being flattened in a plane perpendicular to the axis of the eye portion into Wire-clamping engagement with the unwoven wires within the eye portion. The hole of the eye portion is of such shape as to receive and fit the bolt of a draft clevis when the draft end of the cable grip is inserted in a draft clevis with a minimum of lost motion between the bolt and the eye.
This invention relates to cable grips which comprise a bunch of strands of suitable wire which, except for a portion intermediate its ends, are woven diagonally to form a sheath to receive the end of a cable which is to be pulled through a conduit or passage which is frequently tortuous, or over sheaves or other objects.
The unwoven intermediate portions of the -wire form a pulling loop which may be engaged by a hook or the like connected to a pulling cable.
Heretofore it was proposed to protect the loop portion of the wire against abrasion or other damage by passing the straight strands of wire through a straight metal sleeve of suitable diameter and length and then bending the metal sleeve with the strands therein into a more or less pear-shaped loop, the ends of the tube projecting beyond the loop being diagonally cut away on adjacent sides so that the wires in the tube-ends may be brought together to hold the extending ends of wire strands firmly together. The ends of the sleeve were held together by a ferrule or collar passed over the wires and slid over the ends of the sleeve.
With the cable grip heretofore suggested, in order for the Wires to be drawn or forced through the sleeve, the latter had to have an internal diameter slightly less vthan the diameter of the bunch of wires, and hence there was no substantial gripping 0r clamping action between the sleeve and the wire, except where the wires entering and leaving the loop were brought together.
This has been found to be insufficient under heavy load conditions to hold the wires together against movement relative to each other and relative to the sleeve probably because the limited gripping contact between the adjacent portions of the wire emerges from the tube.
An object of the present invention is to provide a cable grip within a protective sleeve and secure the entire loop portion of the wires in the sleeve against relative movement and movement relative to the body of the sleeve, and thus distribute the load on the bunch of wires over the entire length of the loop.
For this purpose, according to the present invention, after the wires are inserted in the straight metal sleeve so that approximately equal portions of the wires project from opposite ends of the sleeve, then the sleeve is bent ICC into U-form and then further bent to form an eye portilon having projecting leg portions from which the wires emerge. Preferably, the eye portion is formed over a mandrel and the legs are brought close together so as to form a substantially complete eye. After the sleeve is thus formed, the leg portions are held together by a suitable ferrule, and then a deforming force is applied to the ferrule and the abutting parallel leg portions to flatten the sides thereof and force the leg portions of the tube into clamping engagement with the bunch of unwoven wires.
To further clamp the bunch of Wires in the tube, the eye portion of the loop may be deformed to flatten its sides, preferably in a plane at right angles to the plane in which the sides of the leg portions of the sleeve were flattened.
It has been found that by thus flattening the tube so as to cause the wires to lie in a tortuous course in intersecting planes, the resistance of the Wires to bending which would be necessary for the wires to move in such a course in the sleeve, contributes to maintaining the Wires of the loops immobilized with respect to each other and to the sleeve.
By forming the eye portion so that the eye is substantially enclosed, the eye portion may be made to snugly t the bolt of a draft clevis in which the eye may be inserted without appreciable lost motion in all directions between the eye portion and the bolt.
The eye portion of the loop is preferably so made that its flattened sides may closely engage the walls of the slot in a clevis, thereby preventing excessive lateral motion between the eye and the clevis.
The eye portion may be shaped so as to conveniently receive a hook on a drawn cable, in which case the portion of the eye engaged by the hook may be straight instead of curved.
The shape of the eye portion and the aperture therein may be controlled by the shape of the mandrel oven while the sleeve is formed.
Other features and advantages will hereinafter appear.
In the accompanying drawings:
FIG. 1 is a plan view showing a bunch of wires extending through a protective metal sleeve.
FIG. 2 `shows the step of bending the sleeve and the wires contained therein into U form.
FIG. 3 shows the step of forming the eye portion of the sleeve.
FIG. 4 shows a modification of the eye portion shown in FIG. 7.
FIG. 5 shows the projecting ends of the sleeve to which a collar, shown in section, has been applied, and the end portions or legs being flattened into wire-clamping engagement with the bunch of wires contained therein.
FIG. 6 shows the eye portion being deformed into wire-clamping engagement with the wires.
FIG. 7 is a plan view of the pulling end of the cable grip of the present invention with the ferrule shown in section and the wires emerging from the legs being woven diagonally to form an article-gripping sheath.
FIG. 8 is a cross sectional View of the eye portion taken on the line 8 8 of FIG .7.
FIG. 9 is a cross sectional Niew taken on the line 9-9 of FIG. 7.
FIG. l0 shows a portion of a pulling clevis with the eye grip extending into the slot of the pulling clevis and secured therein by a bolt passing through the eye.
As shown in the accompanying drawings, the cable grip of this invention, in its presently preferred form comprises a rigid metal sleeve 10 into which is slid the end of a bunch of wires 11, each of which usually consists of a plurality of twisted strands of wire, to a position in which the sleeve 10 is located substantially midway between the ends of the wires 11. The wire-containing sleeve is then bent into U-shape form, as shown in FIG. 2, by male and female die members 12 and 13.
The U-formed sleeve is then placed in a die block 14 having a mandrel 15 so that the end portions of the sleeve lproject from the block. While in this position, the end portions are forced into parallel contacting engagement by slides 16 and 17 being brought together as shown in FIG. 3, the mandrel 15 forming an eye portion 18 and the end portions forming legs 19 extending from the eye portion 18 in parallel planes perpendicular to the axis of the eye portion.
Preferably, for reasons stated below, the slides 16 and 17 are shaped to so form the sleeve that the eye portion 18 forms a substantially complete circle about the mandrel 15, or at least an arc of substantially more than 180. After the sleeve is formed, as shown in FIG. 3, a ferrule 20 is slid over the legs 19 to hold them together against spreading apart. Then, after placing a mandrel 21 in the eye 18, force is applied to the ferr-ule 20 and the leg portions 19, as shown in FIG. 5, by tools 22 and 23 to deform the ferrule and leg portions and force them into clamping engagement with the bunch of wires in the leg portions of the sleeve substantially as shown in FIG. 9.
After the legs 19 have been flattened, the eye portion 18 is placed between a block 24 with mandrel 25 extending through the eye 18 and a plunger 26, and force is applied to deform the eye part of the metal sleeve, as shown in FIG. `6, to atten and force the eye portion of the sleeve into clamping engagement with the bunch of wires in the eye portion, as shown in FIG. 8. The portions of the wires 11 projecting from the legs 19 of the sleeve are then brought together and woven diagonally to form a tubular sheath 27, in a manner well known in the art, to receive a cable, pipe or other similar elongate article to be gripped and pulled through a conduit or the like by pulling force applied to lthe eye 18.
The pulling end of the present invention with its substantially flat-sided eye 18 is particularly advantageous for use in situations in which the draft member, which is to engage4 it, comprises a clevis 28, a portion of which is shown in FIG. l0. The clevis 28 is provided with a slot 29 and a bolt 30 extending across the slot.
With the pulling end of the present invention, the eye portion may be made so that when it is inserted in the slot 29 the at sides of the eye may almost engage the at walls of the slot to prevent excessive lateral movement of the eye in the slot. Besides, by having the aperture 31 of the eye formed almost as a complete circle, or at least substantially more than a half circle, and having a diameter slightly larger than the diameter of the bolt 30, lengthwise movement of the pulling end relative to the clevis is avoided.
In the broader aspects of this invention, the eye portion of the cable grip need not be substantially circular as shown in FIGS. 5 and 7. For instance, if the draft member on the draft cable is in the form of a hook 32, shown partly in section in FIG. 4, having a flat surface to engage the eye portion 33, the latter may be formed to have its portion 34 straight instead of curved as shown in FIGS.
5 and 7. Even when so formed, it is advantageous that the aperture 35, being of such dimensions that substantial linear movement of the eye portion 33 in its own plane relative to the hook, be limited by the engagement of the hook portion 36 with the portion 34 and the converging portions 37 of the eye portion.
1. In a cable grip having a plurality of strands of wire woven diagonally to form an article gripping sheath, a rigid metal protective sleeve, an intermediate unwoven portion of the plurality of wires extending through said sleeve, said sleeve having an eye portion and parallel leg portions extending substantially radially from the eye portion, said leg portions of the sleeve being deformed on said wires to have flat sides maintaining the wires in the leg portions under compression and in wire clamping engagement with each other and the leg portions of the sleeve whereby the wires are held against movement in the sleeve.
2. A cable grip as dened in claim 1 in which the eye portion of the sleeve is deformed on the wires to have flat sides maintaining the wires in the eye portion of the sleeve under compression and in clamping engagement with each other and with the eye portions of the sleeve whereby the wires are held against movement in the eye portion of the sleeve.
3. A cable grip as dened in claim 1 in which the at sides of the leg portions are in planes transverse to the plane of the eye portion.
4. A cable grip as defined in claim 2 in which the flat sides of the eye portion are in planes transverse to the planes of the llat sides of the leg portions.
5. A cable grip according to claim 1 in which a ferrule surrounds the leg portions to keep them from spreadmg.
6. A cable grip as defined in claim 1 in which the eye portion has an aperture the greater part of which is circular and has a determinate diameter to slidably receive without excessive lost motion a bolt of a clevis to which the eye portion is to be attached.
7. A cable grip as dened in claim 1 in which the attened eye portion has a determinate thickness to slidably t a slot without excessive lost motion of a clevis to which the eye portion is to be attached.
8. A cable grip as defined in claim 1 in which the flattened eye portion has its portion which is opposite the leg portions straight.
References Cited UNITED STATES PATENTS 1,524,009 l/ 1925 Austin 287-81 1,657,722 1/ 1928 Page 287-81 2,847,244 8/ 1958 Di aPalma 24-123.5UX
BERNARD A. GELAK, Primary Examiner U.S. Cl. X.R. 287-81