US2257963A - Rod withdrawing tool - Google Patents

Description

2 sheets-sheet 1 ATTORNEY Ost. 7, 1941 R. J. KENT ROD WITHDRAWING TOOL Filed NOV. 2, 1939 '0a. 7, 1941. R J. KENT 2,257,963

ROD WI THDRAWING TOOL Filed Nov. 2, 1959 2 sheets-sheet 2 BZWWMQ ATTg/QNEV Patented Oct. 7, 1941 UNITED STATE ROD WITImRAwrNqrool.

Robert J. Kent, Jamaica, N. Y., assignor to Bell Telephone Laboratories, Incorporated, New York, N. Y., a corporation of New York Application November 2, 1939, serial No. 392,572

2 Claims.

i 'v This invention relates to rod withdrawing tools and more particularly to tools for withdrawing rods from ducts.

.The'object of the invention is to provide a tool Yfor withdrawing a rod from a duct. The tool may be used, for instance, in withdrawing from 1a duct a rod or a portion of a rod left in the duct by reason of breaking of the rod or breaking or disconnection of a coupling on the rod.

A feature of the invention resides in means provided in the tool for grasping a rod..

Another feature resides in the body structure of the tool.

Other features reside in the form and arrangement of the parts in combination.

In the drawings,

Y Fig. 1 is a side elevational view, partly in section, of a multiple duct Vburied in earth or con.- crete, a rod disposed in one of the ducts and the tool of this invention in a position to be thrust into engagement with the rod. This gure is `drawn to a reduced scale relative to the other gures in the drawings;

Fig. 2 is a side elevational View of the tool;

Fig. 3 is an end view of the front end of the tool, taken from the left of Fig. 2;

Fig. 4 is a side view, partly in section, of a portion of the tool;

Fig. 4A is a view of the same portion'shown in Fig. 4 and with a portion of the rod extending longitudinally through that portion of the tool and Vgrasped by the tool; y Fig. 5'is a cross-sectional View of the part shown in Fig. 4 and taken on the line 55; and, Fig. 6 is a cross-sectional View of Fig. 4 taken on the line 6 6. v In the running of cables of an electrical sysitem through underground ducts it is common ,practice for the cabling crew to thrust a rod 'through a required duct from one manhole to another, each of which is in communication with the duct system. The rod may be equipped with .a suitable tool for cleaning out obstructions in the duct or may be used as a pilot for a cable or winch rope and which in turn may be used to pull in the cable to be laid in the duct. The irod in some instances is made of suitable lengths Aof relatively hard wood with a portion of a separable coupling device provided on each end so that sections of the rod may be readily coupled together in end-to-end relation to form a relatively long sectionalized rod. The rod sometimes becomes broken in the duct or the sections may become uncoupled so that when an attempt is made to withdraw the rod from the duct a portion of the sectionalized rod remains in the duct at some point between the two manholes. The problem then is to remove this portion of the rod from the duct.

As shown in Fig. 1, the tool I has been thrust intoaduct 2 in a multiple duct system 3 which fis buried in-earth or concrete 4. The tool I is in a position from which it can be thrust into engager'oentwith a rod 5. rThe rod 5 is equipped witha coupling 6 and may have become uncoupled at this point from another section 1 of the rod or the section 1 may have become broken as shown at 8. The rod 5 is of much smaller diameter than the duct 2 and normally lies at the bottom of the duct. The coupling 6 is a twopart male and female coupling and has a larger outside diameter than the rod 5 so that the rod 5 and the section 1 thereof are held slightly elevated from the bottom of the duct 2 by the coupling 6.

The tool I as shown in Fig. 2 comprises a tubular body member 9 and a bell-mouthed tubular end portion I which is'joined at its smaller end to the bodyY member 9 and forms the front end of the tool. The body member 9 has asuilciently `large internalr diameter to readily and ylongitudinally receive the rod 5 and coupling 6.

*AT he rear end portion of the body member 9 is 'equipped with a thrust rod I2 which is secured to the outer surface of the body member 9 and extends rearwardly of the body member 9 and in a plane parallel to the outer surface of the body member 9. Since the thrust rod I2 is located on the outside of the body member 9 and is clear of the bore of the tool, it will not interfere with passage of the tool any required distance along the rod 5. The free end of the thrust rod I2 is enlarged and internally bored and threaded as shown at I3 to permit coupling of the thrust rod I2 to a suitably threaded bar I4 shown in Fig. 1 and which serves as an extension of the thrust rod I2 to permit operation .of the tool Within the duet 2 from a remote point such for instance as a manhole, not shown but,

`Whichis in communication with the duct 2.

y The body member 9 carries a set of pivotally supported gripping lingers I5 and has rectangularlaperturesfl vformed in its wall at suitably 'spacedL points to accommodate the gripping iin- .gers I5.

The rectangular apertures I 6 are located in about the central portion of the body member 9 and extend longitudinally thereof and are spaced about equal distances apart. Each gripping linger I5 is transversely apertured at a point oiset from its center and is pivotally `supported on a pin I'I, the lingers I5 being free to turn on the pins I'I and the pins II being secured at their end portions on spaced lugs I8 formed on `the outersurface of the body member S and located on opposite sides of the rectangular apertures I5. The spaced lugs I8 may be simply deposits of metal formed on the outer surface `of the body member 9 and forming welds .between the ends of the pins I'I and the body member '9 or may be of any particular form and Vstructure found suitable for the purpose. The gripping iingers I5 are triangular in form and are transversely apertured at I9 to allow passage therethrough of a helical spring 2'0, the aperture I9 being located offset from the pivotal point. of support of the gripping linger I5 and nearer the apex of the gripping linger than the pin II and toward the rear of the body member 9. The helical `spring is 'disposed in the form of a ring about the body member 9, the ends of the spring being hooked together as shown at 2l, `Fig. 6. The points of passage of the spring 20 through the gripping lingers I5 relative to the pivotal points of support of the lingers and the diameter of the ring formed by the spring are such that the spring 2D tilts the gripping lingers I5 on the pins .ll and urges sharpened end portions 2i of the gripping fingers I 5 through the apertures I5 and toward 'the axial center of the body member 9. The sharpened end portions 2I of the gripping fingers I5 are of chisellike 'form and converge about the axial center of the body member `9 and are directed toward the rear of the body member 9. The portions of the gripping ngers I5 extending within the body member 9 cooperatively form, in a sense, a relatively small but enlargeable triangular passageway within the body member 9. The gripping lingers I5 are arranged to allow the tool I to be telescopically passed about therod 5 when the point of entrance of the rod 5 is through the bellmouthed end portion Ill and toward the rear of the tool. In Vthis movement of the tool I about the rod 5, the gripping lingers I5 rock on their pivotal Ypoints of support so that the sharpened end portions 2| are displaced from their normal positions and are moved outwardly toward the inner wall surface of the body member 9. Figs. 2, 3, 4, 5 and u6 show the gripping lingers I5 in their normal positions; and Fig. 4A shows the -positions ofthe gripping fingers I5 when the rod y5 is within the tool I.

When the gripping lingers I5 are rocked on their pivotal points of support to allow passage -oi the tool I about the rod 5, the helical spring 2li `is stretched since the point of passage of the spring 25 through the linger I5 is nearer the apex of the nger E5 than'the pivotal point of support of the linger and towards the rear of the tool I. The spring 29 is therefore constantly urging the sharpened end portions 2l of the gripping fingers I5 toward the rod 5 and in position to engage the edge portion of the coupling 6 on the rod 5 or even to slightly dig into the outer surface of the rod '5 when a pulling action is applied to the tool I. If the tool I is moved along the duct 2 from the position shown in Fig. 1 and so that 'the tool l is telescopically passed about the section l of the rod 5, and over the coupling 6 and so that the coupling 6 lies in the rear portion 'of the tool and beyond vthe pointed ends 2| of the coupling E.

the gripping lingers I5, any rearward pull applied to the tool I will bring the pointed ends 2I of the fingers I5 against the left-hand edge of The spring v2E) will prevent the pointed ends of the lingers I5 from jumping over the left-hand edge portion of the coupling 6 when a further pulling action is applied to the tool I. Withdrawal of the tool I from the duct 2 will then result in withdrawal also of the rod `5 from the duct 2.

.gripping action of the tool I is shown in Fig. 4A.

` What is claimed is:

LA. rod withdrawing tool comprising in combination, a tubular body transversely apertured at spaced points, 4the transverse apertures being arranged around a common central point, a bellmouthed front end on said body, a set of equally spaced pins mounted on said rbody and extending across the transverse apertures in said body, a set of bevel pointed lingers pivotally supported on said pins and extending inwardly through the transverse apertures in said body and angularly converging about the axial center of said body, the pointed ends of said lingers being directed toward the rear of said body, helical spring `means arranged in the form of a completely 'closed ring extending around said body and vtransversely through each of said lingers at a point between. the pivotal point 4of support and the pointed end thereof and urging the bevel pointed ends of said vlingers toward the axial center of said body, a thrust rod secured to an outer side surface of said body and extending in lparallel `with and rearwardly of said body in a plane entirely clear of the bore of said body and `an enlarged internally threaded end portion on said `thrust rod.

2. In a rod withdrawing tool comprising a tubular body adapted to be passed longitudinally laboutthe rod and having .a series of spaced apertures formed in `the side wall of the body, in combination, a set of pins mounted on said body and extending transversely across said apertures,

'a vset 'of triangular lingers pivotally supported on said pins, veach of said lingers being pivotally supported at a point offset from its apex and having an aperture formed directly under the apex, a Ihelical spring arranged in the form of a Vring Iand closelyembracing said body, said spring extending through the apertures in said `fingers directly under A.the apices of the lingers and tilting said lingers so that a portion of each ofrsaijd lingers extends within the bore of said body, the inwardly directed ends of said fingers Vbeing sharpened to engage the rod, a thrust rod line of bore of said body.

ROBERT J. KENT.

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