US 3166810 A
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Description (OCR text may contain errors)
G. C. ENSLEY Jan. 26, 1965 CABLE GRIP 2 Sheets-Sheet 1 ilgd July l0, 1965 A, JAummumJ l Il aan@ 7m Jan. 26, 1965 G. c. ENSLEY 3,166,810
CABLE GRIP Filed July lO, 1963 2 Sheets-Sheet 2 INVENTOR. 3L VER 6'. ENSLE Y www United States Patent Oice ll Patented Jan. 26, .1965
v3,165,810 CABLE GRIP Glover C. Ensley, 52S N. Woodland Drive, Kansas City North, Mo. Filed July 10, 1963, Ser. No. 294,122 3 Claims. (Cl. ZAL-125) This invention relates to improvements in devices for drawing or pulling electric cable :through tubular conduits or the like.
The Vprincipal objects of the present invention are: ,to provide acable grip which easily and quickly secures to the free end of a cable for drawing same through a conduit; to provide such a ygrip which holds the cable securely while under great tensile force and is easily pulled over sheaves or through sharp bends in the conduit; to provide such a grip which is easily and quickly attached to a pull rope loop and presents no tendency to cut the pull rope; to provide such a device which may be smoothly drawn through conduit Without significant danger of hanging up; and to `provide such a device which is simple in construction, long-lived, and easily disengaged from the cable after pulling.
Other objects and advantages of this invention will become apparent from the following description taken in connection with the accompanying drawings wherein are set forth by way of illustration and example certain embodiments of this invention.
FIG. 1 is :a perspective view of a cable grip embodying this invention.
FIG. 2 is a vertical cross-sectional View through the grip taken on the line 2 2, FIG. 3, particularly showing thewire-receiving bores and wire rope loop anchor.
FIG. 3 is a transverse cross-sectional View through the 'grip taken on the line 3 3, FIG. 2, particularly `showing the cooperation between a cone-pointed set screw and an aligned, conical depression in a wire-receiving bore for securing a wire strand in the grip body.
FIG. 4 is a vertical cross-sectional View through the grip taken on the line 4 4, FIG. 3, showing thevwire strand Ypartially urged into a pair of conical depressions.
FIG.5 is a side elevational View of the grip on a reducedk yscale showing the insertion of theV grip body through a pull rope loop for the pull rope.
FIG. 6 isasideelevational viewof the. grip and extending wire-strands Vof a cable on areduced scale showing the strands in positionfor insertion into respective wire-receiving bores.
FIG. 7 is a fragmentary perspective view on a reduced scale illustrating the use of thegrip in pulling cable over a sheave.
FIG. 8 is a partially schematic sectional elevation on a reduced scale illustrating the grip pulling a cable through a QO-degree conduit bend.
Referring to the drawings in more detail:
The reference numeral-.1 generally indicates a cable grip embodying this invention for drawing electric power cable 2 through conduit 3 or over a rotatable sheave 4. The cable 2 may be of any well known type having core wire strands or outer multiple wire strands which may project forwardly from the protective sheath 6 of the cable. The cable grip 1 comprises a generally cylindrical body 7 having a top surface 8 'and a bottom surface 9 respectively having peripheral beveled portions 9. A coaxial bore 10 extends through the cylindrical body 7 and changes abruptly in diameter near the center of the body forming an annular internal shoulder 11. The shoulder 11 is thereby located in the bore 10 between a larger diameter section 12 communicating with the bottom surface 9 and `a smaller diameter section 13 communicating with the top surface 8.
Two lengths 14 of flexible wire rope form a loop portion 15 located. externally of the body 7 above the top surface 8. Opposite end portions 16 of the lengths 14 together extend longitudinally past the top surfaces, 'through the smaller section 13, past the shoulder 11 and into the larger `section 12. An elongated cylindrical plug 1.7 is axially `and rotatably slidable in the larger section 12 but greater in diameter than the smaller section 13. .The plug 17 is of a type commonly used for anchoring wire rope and may be secured thereto by great pressure which induces plastic deformation of the plug metal into intimate contact with the wire rope strands. 'Ille plug 17 receives and is securely anchored to the wire rope end portions 11S-while the latter are extended past the lbottom surface 9 and the plug is subsequently withdrawn into the-large diameter bore section 12 where-it bears axially against the annular shoulder 11 for preventing the further withdrawal of the end portions 16 from the body during pull on the loop portion 15A By permitting relative rotational movement between the shoulder 11 and plug 17, the body 7 may be easily :axially rotated withprespect to the loop portion 15 for ease in securingy to a cable after attaching to a pull -ropeas described hereinafter.
A resilient flexible elongated protective sleeve 18` covers the loop portion 15 substantially symmetrically with respect to the body over an angle of greater than degrees to prevent scoring of the wire rope against the inside surface of the conduit and also to prevent cutting of the pull rope by wire rope strands. n
VA plurality of wire-receiving bores 19, in the illustrated example four, extend from the bottom surface 9 upwardly through the body 7, opening into the top surface 8. The wire-receiving bores 19 extend parallel to the cylindrical taxis 20 of the body 7 and a-re ,equally radially andpequally circumferentially spaced about .the axis 7. The wire-receiving bores 19 lare beveledat 21 adjacent the top and bottom surfaces 8 and 9 to prevent thel danger of cutting wire strands during pulling as noted hereinafter.
. A pairof Yspaced-apart threaded bores 22 extend transrversely into the body 7 for each wire-receiving bore 19. The threaded bores 22 extend at right angles to respective planes containing the body cylindricalaxis 20. The bores 22 transversely communicate with the respective `wire- Vreceiving bores 19 and enlarged counterbores 23 extend from the surface of the body 7 coaxially inwardly to communicate withthe respective threaded bores 22 for easily depositing cone-point set screws .2A-v thereintro. Conical depressions 25 are located in the body 7 'respectively coaxially yaligned with each of the threaded lbores 22 and communicate with the respective wire-receiving bores 19 in* positions opposed to the threaded bores 22. The set screws 24 are threadedly received in the threaded bores 22 and are of a length wherebyrthey extend beneath the surface of the body 7 when projecting into la wire-receiv ing bore 19. It is noted `that the continued rotation of the respective set, screws 24 will extend the oone point 26 thereof into the respective depression 25 if no wire strand obstruction is encountered.
If desired, a central band groove 2S may be provided encircling the body 7 to mount an instruction or indentifying label 26' lthereon in a safe position.
In use, a pull rope 27 is threaded through the conduit 3 in a conventional manner and formed into a loop 28 at the end of the conduit into which the cable 2 is to be inserted. The pull rope loop 28 is passed through the wire rope loop portion 15 and -around the body 7, as best illustrated in FIG. 5 A separating force between the body 7 and the loop 28 causes the loop portion 15 to become iirmly anchored or engaged with the cylindrical body 7 as illustrated in FIG. 6. The strands of wire 5 extending forwardly `from the cable are then inserted areasro into the wire-receiving bores from the bottom surface 9 to a point where the ends 29 thereof extend past the respective threaded bores 22 closest to the top surface 8. The respective set screws 24 are then urged inwardly by rotating with a conventional Allen wrench 3i! until the cone points 26 urge portions Si of the wire strands 5 partially into the conical depressions 25, producing a secure coupling between the body 7 and respective wire strands 5 which has sutiicient holding power to cause a tensile parting of the wire strands themselves rather than slippage within the coupling. Thus, the cable 2 is secured with respect lto the body for pulling the cable through the conduit 3 by the loop portion l5.
In pulling the pull rope 27, any convenient tensile force applying apparatus may be used, in the illustrated example a caps'tan type cable puller 32 is illustrated anchored to suit-able rigid structure 33. The beveled portions Si' at the top surface 8 prevent hanging up in the conduit due to small obstructions. It is noted that the body 7 is relatively short in length compared to the diameter thereof, that is, ythe length approximately equals the diameter, whereby the cable grip easily passes around tight 90-degree bends in the conduit such as that illustrated thereof, the Wire strands 5 are easily withdrawn from the wire-receiving bores i9 by backing oir" the respective set screws 2.4 and the cable grip may be easily disengaged from .the pull rope loop 25 by reversing the looping step illustrated in FIG. 5.
It is to be understood that while one example of this invention has been illustrated and described, it is not to be limited to thespecic form or arrangement of parts herein described and shown except insofar as such limitations are included in the claims.
What I claim and desire to secure Letters Patent is:
1. A cable grip for drawing multiple wire strand cable through conduit comprising: a body of generally cylindiicalV shape and having a length not less than the diameter, saidrbody having end surfaces and anchoring means operatively associated with one end surface, pulling -means secured to said anchoring means, a plurality of wire-receiving bores extending longitudinally yfrom the other end surface into said body generally axially thereof and spaced radially outwardly of the axis of said body,
' said body having an outer side surface, said body having threaded bores for each wire-receivin g bore, said threaded bores having openings in the outer side surfaceV of the Vbody spaced circumferentially therearound and extending of a cable are inserted into the respective wire-receiving bores from said other end surface and engaged by said respective set screws to secure the cable with respect 4t0 said body for pulling the cable through conduit by said pulling means.
2. The cable grip as set forth in claim l wherein each of said wire-receiving bores has a pair of said spacedapart threaded bores communicating therewith, and said body has depressions in the wire-receiving bores in opposed relation to and coaxially aligned with each of said threaded bores.
3. A cable grip lfor drawing multiple wire strand cable through conduit comprising: a generally cylindrical body of roughly equal length to diameter, said body having a top and bottom surface and a coaxial bore therethrough, said coaxial bore changing abruptly in diameter along the length thereof forming an annular shoulder therein between a larger diameter section communicating with said bottom surface and a smaller diameter section cornrnunicating with said top surface, a length of flexible wire rope having a loop portion located above said top surface and opposite end portions together extending longitudinally through said smaller section past said shoulder and into sm'd larger section, a plug sli-dably received in said larger section but greater in diameter than said smaller section, said plug receiving and securely anchoring said end portions therein and bearing axially against said annular shoulder for preventing the withdrawal of said end portions from said body toward said top surface, there being a plurality of wire-receiving bores extending from said bottom surface upwardly into said body and spaced about said body cylindrical axis, there being a pair of spaced-apart threaded bores for each of said lwire-receiving bores, said threaded bores extending transversely into said body and transversely communicating with said respective Wire-receiving bores, there being depressions in said body respectively coaxially aligned with said threaded bores and communicating with said respective wire-receiving bores in positions opposed to said threaded bores, and set screws threadedly engaged in said threaded bores and extending beneath the surface of said body when projecting into said Wire-receiving bores, whereby separate wire strands of ya cable are inserted upwardly into said respective wire-receiving bores at said bottom surface and urged at spaced-apart locations partially into said depressions by said set screws to secure the cable with respect to said body for pulling the cable through conduit by said loop portion.
References Cited by the Examiner UNITED STATES PATENTS y 7/ 33 Parrish Erl-243.2
DNLEY l. STOCKING, Primary Examiner.