US2159840A - Detachable drill bit shank slotting device - Google Patents

Description

C. E. COOK.

May 23, 1939.

DETACHABLE DRILL BI'T SHANK SLOTTING DEVICE' Filed Sept. 23, 1957 A35". A 3. A m 2 l x v v v N M 9 8 1 6 A: A; r

[LEnEUDK v Patented May 23, 1939 UNITED STATES PATENT OFFICE 1 2,159,840 DETACHABLE DRILL BIT SHANK SLOTTING DEVICE Charles Edward Cook, South Porcupine, Ontario, Canada, assignor to International Detachable Bits & Equipment, Limited, Timmins, Ontario, Canada, a corporation of Ontario, Canada Application September 23, 1937, Serial No. 165,239

1 Claim. (Cl. 76-95) tail cross-section in the shank end solely by ing application Serial No. 165,238 filed September 23, 1937, Methods of forming detachable drill bit shanks. My device is designed to forge the straight walled slot in the shank end into a slot of dovetail cross-section whichis the ultimate form it assumes, solely by a forging operation.

With the above and other objects in view which will hereinafter appear as the specification proceeds, my invention consists, inits preferred embodiment, of the construction and'arrangement all as hereinafter described and illustrated in the accompanying drawing in which:

Fig. 1 represents a vertical section through my device showing the detachable drill bit shank in position therein ready to be dollied and the device mounted in a drill steel sharpener.

Fig. 2 is a similar view to Fig. 1 only showing the shank end provided with the straight walled slot illustrated in Fig. 1 dollied into one of dovetail cross-section by my device.

Fig. 3 is a vertical cross-section through line 3-3 (Fig. 2).

Fig. 4 is a vertical cross-section through the the , line 44 (Fig. 2).

Fig. 5 is a perspective detail of my dolly, and

Fig. 6 is a plan view ofthe shank end showing the removable head of the dolly applied thereto but partially detached therefrom.

Like characters of reference indicate corresponding parts in the different views of the draw- My device comprises a divided clamping die having a lower or stationary portion l adapted to be mounted upon the lower die block 2 of a drill steel sharpener, and an upper or vertically movable portion 3 adapted to be mounted on the ram 4 of the drill steel sharpener and to coact with the portion I for clamping the detachable drill bit shank A in position therebetween.

The interior of the divided die is enlarged at one end to receive the enlarged end of the shank. When such shank is in position in the clamping die its end is dollied by a dolly 5 adapted to be mounted in the dollying attachment (not shown) 01 the drill steel sharpener.

The dolly 5 has a cylindrical bore 6 extending axially from its end which receives the removable cylindrical head I. The end face of the head is provided with a diametrically extending rib 8 of dovetail cross-section of the form of the slot in the shank end it is designed to forge.

Upon the heated detachable drill bit shank A (which has had previously a diametrical straight walled slot 9 forged in the end thereof, for instance, by a dollying operation such as described in the above mentioned co-pending application) being clamped between the portions l and 3 of the clamping die and the dolly 5 being aligned with its longitudinal. axis coincident with the longitudinal axis of the shank A, the dollying attachment is actuated with the result that the reciprocation of the dolly 5 causes its head 6 to impart a dollying action upon the end of such shank swaging such end so that the straight walled slot 9 therein is forged into a slot Ill of dovetail cross-section conforming with the shape of the rib 8 which has been initially inserted into the slot 9. 1

When the dollying operation is complete the dolly 5 is withdrawn leaving the head 6 attached to the shank. The ram 4 is then retracted and the shank with the head 6 attached is removed from the clamping die. By means of a hammer the head is then tapped transversely with respect to the shank as illustrated in Fig. 6 wherein the rib 8 is detached from the slot ll) of dovetail cross-section formed in the shank end by the dollying operation.

The shank A is now ready foruse without the necessity of any machining whatsoever and the detachable bit may be attached thereto.

From the description it will be apparent that I have originated a device which will forge the shank end into the ultimte form necessary for its connection to the detachable bit.

Although I have described and shown my device as of. the form suitable for forging the end of the shank into the required shape for. connection to a detachable bit of the specific construction described in United States Patent No. 2,030,576, issued February 11, 1936, it will be understood that by varying the configuration of the end of the head 6 my device may be used for forging the end of the shank to receive detachable bits of other constructions.

By the use of my-device any machining, milling or other operations entailing a removal of metal from the shank, the employment of special machines and consequent highly skilled labour, are avoided as the shank end is formed by my device in a standard drill steel sharpener entirely by a forging operation.

Such device is equally applicable for forging the ends of new shanks or for reconditioning worn or damaged shanks which have been previously used.

What I claim as my invention is:

. CHARLES EDWARD COOK.

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