US2244824A - Extracting tool - Google Patents

Description

June 1o, 1541. H. CAMINEZ 2,244,824

EXTRACTING 'rooiJ Filed Jan. 24. 1939 INVENTOR A492020 CQM//Vfz TTORNEY Patented June 10, 1941 Exrasc'rmc roos Harold Caminos, Kew Gardens, N. Y., assignor to Aircraft Screw Products Company, Inc., Long Island City, N. Y., a corporation of New York Application January 24, 1939, Serial No. 252,557

2 Claims.

The present invention relates to a tool for extracting a wire coil embedded in the Ithread groove of a female screw member as described in my copending applications Ser. Nos. 91,263, 190,-

168, and 246,814, filed July 18, 1936, Feb. 12, 1938,

and Dec. 20, 1938, respectively. In the removing of such coils from their seats in threadgrooves diillculties are encountered, because the coil tends to expand and thus to wedge in the thread groove so much so that any torque to remove the coil is counteracted by friction.

The object of the present invention is the provision of a tool for facilitating the removal of such coil, and the invention mainly consists in a tapered instrument adapted to grip the flrst convolution from the interior of the coil, and to apply thereto a torque in such. a sense as to screw the coil out of the thread groove. In this manner, the second and the following. convolution will contract and readily follow the movement oi the tool.

Further details and objects of the invention will be apparent from the description hereinafter and the appended drawing illustrating an embodiment thereof by way of example.

In the drawing, Fig. 1 is a side elevation of the tool; Fig. 2, a sectional view along line 2-2 of Fig. l, and Fig. 3, a sectionalview of a female threaded member with a wire coil therein and the new extracting tool applied for removal oi' the coil.

Referring now to the drawing the tool consists of a head portion I, a shank portion' 2 -and a tapered end portion l. The top portion is pro- 'vided with a means, e. g. handle I, for applying a torque about the longitudinal axis I. The end portion 3 is tapered and has at least lone sharp edge intended to engage with the ilrst convolution of a coil. In the preferred embodiment the portion 3 has a four cornered cross-section as shown in Fig. 2. Two-corners 8 are hook-like projecting from the substantially rectangular cross-sectional area and are sharpened so as to grip the coil securely when the tool is used. .For the removal of a wire coil 1 embedded in the thread groove 8 of a female member 9v as shown in Fig. 3, the tool is pushed with its end portion l into the coil so that the corners 6 bite into the ilrst convolution I0 of the coil. By 'turning the tool in such a sense as to screw the coil out of the thread groove 8, al1 convolutions will be contracted owing to the friction between the coil and the female member 9, except the first convolution whichis spread by the tool proper. Thereby the frictionris sumciently reduced for an easy removal of the coil.

I have found that the illustrated form of the tool giv'es the best results in removing wire coils of the type described in virtue of the following prevailing conditions: In general, the wire is made of a hard material, but because of its shape is fairly resilient. It is, therefore, necessary that the extracting tool be so designed that it can imbed itself into the hard wire without causing much radial pressure between the hard wire and the thread groove in which it is fed. If much radial pressure is exerted, and particularly if such pressure is exerted simultaneously at many points of the periphery of one convolution. the hard wire and especially its end, will catch into the softer threaded groove thereby damaging the tapped hole. One pair of diametrically opposed edges, therefore, produces the best results. On

the other hand, a tool having only two edges t' vtorque which is applied through the edges l will bear not only against the latter but also against" the edges I'. In this manner, the extracted portion of the coil will be suiliciently supported to transmit the extracting force to the convolutions which are still embedded in the thread groove. 'Ihe blunt edges offer the additional advantage that they guide the tool so as to engage the coil with its two cutting edges at approximately diametrically opposite points.

What I claim: l

1. 'An extracting tool for the removal of a wire coil embedded in the thread groove of a female screw member comprising a shank portion and a tapered endportion, and means for applying a Atorque about the longitudinal axis of the tool,

said tapered end portion including two projecting cutting edges diametrically opposite each other, and two non-cutting portions intermediate said cutting edges, said non-cutting portions being arranged on a smaller diameter than the cutting edges but at such a distance from the shank axis that coil convolutions contracted by said tool ap- 2 emesse plied thereto may bear against said non-cutting portions.

2. An extracting tool for the removal of e, wire coil embedded in the thread groove of a, female screw member comprising a shank portion and e. tapered end portion, and means for applying e torque about the longitudinal axis of the tool,

said tapered end portion having a substantially square cross-section. the ends of the opposite sides of the square, at one pair of diametrically opposed corners, projecting slightly beyond the outline of a true square, and the adjacent ends of the other pair of sides being curved so as to form hollow cutting edges with said projecting ends respectively.

HAROLD CAMINEZ.

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