US275860A - Bit-brace fastening - Google Patents

Description

(No Model.)

B. E! BOSE.

BIT BRAOE FASTENING.

No. 275,860. Patented Apr. 17,1883.

UNITED STATES PATENT OFFICE.

ELMORE ErRQSE, OF SPRINGFIELD, MASSACHUSETTS.

BlT-BRACE FASTENING.

SPECIFICATION forming part of Letters Patent No. 275,860, dated April 17, 1883.

(No model.)

To all whom it may concern:

Be it known that I, ELMORE E. RosE, of Springfield, in the county of Hampdeu and State of Massachusetts, have invented a new and useful Improvement in Bit-Brace Fastenings, of which the following is a specification and description.

The object of my invention is to provide a fastening for bit-braces and breast-drills in which to secure the drill or boring-bit,whereby the drill or boring-bitwill be securely held during the operation of boring or drilling; and I accomplish this by the mechanism substantially as hereinafter described, and illustrated in the accompanying drawings, in which- Figure I is a side view of a breast-drill provided with my improved fastening. Fig. II is a side view of myimproved fastening as applied to a bit-stock. Fig. III isa longitudinal section of the fastening at line B of Fig. II. Fig. IV is an end view of the fastening. Fig. V is a perspective view of thejaws, jaw-stem, and the block which holds and actuates the jaws. Fig. VI is a perspective view of the jaw-stem to which the jaws are secured. Fig. VII is a perspective view of the threaded block which is inserted into thejaw-stem and engages with the interior thread of the operating-sleeve, and Fig. VIII is a perspective view of one of the springs which operate to open the jaws of the fastening.

In the drawings, 2 represents the shank of a bit-brace or drill-holder, to which the fastening is secured. 1 represents the socket, which is hollow, and through which is made a mortise, 18. This socket 1 is permanently secured to the shank 2 by being made solid therewith or by being brazed thereto, and is provided with asleeve, 3, having an interior screw-thread made therein nearly or quiteits whole length. Thejaws 11 are each provided with a recess, 10, made on theinside of the jaw atalittle distance from the inner end of each, which recess engages on a laterally-projectinglip, 9, of corresponding form, made on each side at the end of thejaw-stem S, and two narrow cuts or slots, 13, are made in thejaw-stem, one on each side of and close to the shank, into each of which is secured a flat spring, 12, preferably by upsetting the metal of the jaw-stem against the spring, so that each spring will be held firmly in its slot in the jaw-stem, with its freeend bearing against the outer face of the jaw at the inner end, as shown clearly in Figs. III and V, the inner end of the jaw being preferably beveled for the bearing of the spring against it, as shown at 15 in Fig. V. The outer face of each jaw, at 17, is inclined inward near its outer end and for a short distance from the end with referenee to the remainder of its length, as shown in Figs. III and V, and this outer face of each jaw is forced outward against the end of the opening 16 in the socket by the inward pressure ofeach spring 12 against its jaw behind the lip 9. A block, 6, having a screw-thread made on each end to engage with the screw-thread on the interior of the sleeve 3, is fitted to and inserted in a mortise, 14, made through the enlarged part of thejawstem, and an annular groove,5,is made around the socket 1, inside the sleeve 3.

To put the parts together the jaws 11 are placed one on each side the shank 8, with the lips 9 in the recesses 10 on the inside of the jaws, and with the free end of each spring 12 hearing on the outer face of the jaw or on the beveled recess 15 at the inner end of thejaw, and the jaw-stem is then inserted into the through said jaw-stem coinciding with the mortise 18 through the socket. block 6 is then inserted into the mortise 14 through the mortise 18 in the socket into its position shown in Fig. III, and the sleeve 3, which, before the block (3 was inserted, was moved back as far as possible upon the shank of the bit-stock, is then turned forward and screwed onto the block 6, with the forward end of the sleeve against the shoulder 20, and a screw, 4, is then turned into a threaded hole made in the sleeve, with the inner end of the screw in the annular groove 5, which holds the sleeve in its placeon the socket. As the sleeve 3 is turned in one direction the block 6, jawstem, and jaws are moved forward, and as the springs 12 press inward against the inner ends of the jaws their outer ends are opened and cause the inclined outer side of each to ride against the end of the opening in the socket at the end. If the sleeve be turned in the other direction, the block 6 and jaw-stem are moved backward, drawing thejaws in again, and as socket lat the open end, with the mortise let,

The threaded the inclined back sides of the jaws ride against the ends of the opening in the end of the socket the jaws are forced together, firmly gripping the shank of a bit or adrill, it placed between the jaws, so that the bit or drill will be firmly held in the jaws while boring with the brace.

It is evident that this device may be secured to the shank of any ordinary drill-stock as well as that of a bit-brace without departing from the invention in the least.

The opening in the end of the socket is made of the proper width to just receive the jaws in the direction of their thickness, so that when the jaws are in place in the socket they just fit the opening as to their thickness, but so as to slide freely therein, with the inclines on the jaws riding against the ends of the opening in said socket.

Having thus described my invention, what I claim as new, is-

1. The combination, in an improved bit-brace fastening, of the mortised jaw-stem 8, the threaded block 6, the recessed jaws 11,inclined of the shank, and an incline on the outside of 35 each jaw, near its outer end, to ride against the end of the opening in the socket, two springs secured in said jaw-stem, with their free ends pressing inward against the inner ends of the jaws, and a block fitted and inserted into the slot or mortise through said jaw-stem, substantially as described.

, ELMORE E. ROSE. \Vitnesses:

T. A. CURTIS, N. E. DWINNELL.

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