US461617A - Bit-brace - Google Patents

Description

(No Model.)

O. PEGK. BIT BRAGE.

'Patented 0015.20, 1891.

WITNESS@ NITED :STATES PATENT OFFICE.

OBED PECK, OF ROWE, MASSACHUSETTS.

BIT-BRAC E.

SPECIFICATION forming part of Letters Patent No. 461,617, dated October 20, 1891.

Application tiled January 13, 1891. Serial No. 377,601. (No model.)

To @ZZ whom it may concern.-

`Be it known that LOBED PECK, of Rowe, in the county of Franklin, State of Massachusetts, have invented certain new and useful Improvements in Bit-Braces, of which the following is a description sufficiently full, clear, and exact to enable any person skilled in the art or science to which said invention appertains to make and use the same, reference being had lto the accompanying drawings, forming part of this specification, in which- Figure 1 is a side elevation of my improved bit-brace; Fig. 2, a vertical transverse section of the head or rose; Fig. 3, an end elevation of the chuck; Fig. 4, a vertical longitudinal section of the same, taken between the jaws; Fig. 5, a like View taken through the jaws, and Fig. 6 a sectional view showing-'a drillbit in position in the chuck.

Like letters and figures of reference indicate corresponding parts in the different figures of the drawings.

My invention relates especially to an improvement in the chuck and rose of bit-braces; and it consists in certain novel features hereinafter fully set forth and claimed, the object being to produce a simpler, cheaper, and more eifective device of this character than is now in ordinary use.

The nature and operation of the improvement will be readily understood by all conversant with such matters from the following explanation. l

The chuck B is secured to one end of the sweep by a pin Z). The body (Z of the chuck is reduced at f, and a sleeve gis fitted to rotate on said reduced portion in the ordinary manner. Said sleeve is screw-threaded interiorly at h. Two flaring spring-jaws t' have their innerends screw-threaded atj and work in the threaded portion of said sleeve, the heads k of said jaws being interiorly grooved at 1 and adapted to iare from the mouth of the chuckwhen projected by the screw in the ordinary manner. The body d of the chuck is provided centrally with an opening m rectangular in cross-section, and the walls of which converge inwardly, the jaws i working on opposite sides of said socket in the usual manner. This socket is of the ordinary form employed to center a square-headed tool.

In my improvement I extend the socket m into the body of the chuck at p, said extension being circularin horizontal section and having its walls converging continuously from the rectangular walls of said socket to a point q at the bottom. By this construction the chuck may be employed for holding a round-shank tool or boring-bit, as C, the head of said bit dropping evenlylinto said socket, and when clamped byI the jaws being firmly centered thereby, as shown in Fig. 6.

The rose D is mounted as follows: The opposite end of the sweep A is cone-shaped at r, to form a step for said rose. An annular groove t is formed in said sweep. The rosebody 1J is constructed of metal chambered to receive the sweep-end, and provided interiorly with a seat w forsaid con e-shaped step. Said body o is provided interiorly with a chamber 15, with which the groove t in the sweep-end registers. An opening 17 leads through said body into said chamber and a similar opening 18 (see Fig. 1) leads into the sweep-socket above said chamber. A wooden head 16 is secured to said body by means of brads or projections 19, which penetrate said head, and a screw 20, turned into said body and resting in an annular rabbet in said head. The rose is secured in position on the sweep by means of Babbitt metal 21, which is poured into the chamber 15 through the opening 17, and which enters the groove t in said sweep. The duct 18 serves to admit oil to the cone bearing, and the Babbitt 2l forms an additional lubricant for the rose while preventing it from being withdrawn from the sweep.

The rose mounted as described, while permitting the sweep to rotate freely prevents all lateral movement and enables the wear to be readily taken up by rabbeting.

The circular or cone-shaped socket forms a bearing for the round shank of the tool C and prevents the saine from rocking inv the jaws when in use, as freq uentlyhappens when such tool is inserted in the ordinary rectangular IOO jaws, said socket being angular in cross-sec tion in its outer portion and circular in crosssection in its inner portion and having its Walls converging continuously inward, substantially as and for the purpose set forth.

3. In a bit-brace, the sweep A, having the cone-step 71 and groove t, in combination with the rose D, comprising the body n, chambered at 15, and provided with the seat w, and brads 19, the wooden head 16, the screw 20, turned into said body and projecting into a rabbet in said head, and the Babbitt metal 2l in said chamber, all being arranged to operate substantially as described.

OBED PECK.

fitnessesz O. M. SHAW, K. DURFEE.

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