US1380554A - Drill - Google Patents

Description

A. L. HAWKESWORTH.

DRILL.

APPLICATION FILED MAR.2I, I9I9.

L38U 554v Patented June 7, 1921.

v Arz/wL-jm/marm- 4 ATTORNEY.

ARTHUR L. HAWKESWORTH, 0F BUTTE, MONTANA.

. DRILL.

, Specification of Letters Patent.

Patented June "3, 1921i.

Application fi1ed Mar'ch 21, 1919. Serial No. 283,954.

tion being to provide means for effectively locking the bit to the shank of the drill and yet permit of its ready removal when the occasion arises to detach the bit for purposes of sharpening the same, or replacing a worn out bit with a new one. The advantages of the improved construction will be fully apparent from the following detailed description in connection with the accompanying drawings in which-- Figure 1 represents an elevation of a drill turned so as to present the wide ends of the central interlocking tongue and groove of the bit and shank respectively; Fig. 2 is a side elevation of the drill; Fig. 3 is an eleva tion of the bit detached and turned to present the narrow end of its tongue; Fig. 4.- is an elevation of the shank turned to present the narrow end of its groove; Fig. 5 is a bottom plan of the bit; and Fig. 6 is an end view of the shank showing in plan the several formations cooperating with the formations on the bottom of the bit.

Referring to the drawings, 1, represents a a drill-bar or shank provided with an axial pasage-way or duct (4 for the circulation of water usually employed in drilling operations as well understood in the art. The shank terminates at one end (the end opposite that from which the same is operated) in a tapering transverse groove 2 disposed across the axis of the shank, the groove being of uniform depth and being disposed on a diagonal or at an incline to the axis (longitudinal) of the shank. The end faces h, h, of the shank on either side of the groove are disposed in the same plane, said plane being parallel with the plane of the bottom of the groove. The taper of the side or bounding walls of the groove is in a direction away from the cutting end of the drill for a reason to presently appear. Leading from the sides of the groove 2 are recesses 3, 3, of

uniform and equal depth, the bottoms of the recesses under the circumstances being necessarily parallel to the conver ing side walls-of the groove from which t ey lead. The bit 4 is formed or provided with a tongue 5 snugly fitting the groove 2, said tongue being provided with side ribs 6, 6, cooperating wtih the recesses 3, 3. To attach the bit to the shank, thetongue 5 is inserted with its narrow end into the wide end of the groove 2, the ribs 6, 6, at the same time being received by the recesses 3, 3. By then moving the bit across the shank the full llmit or until further movement is arrested .by the converging walls of the groove, the

bit will be in proper working position. WVhen in position the duct a with which the bit is provided will be in alinement with the duct a of the shank so that the water is free to flow'to the surface being drilled.

The taper of the groove 2 (and necessarily that of the tongue 5) being away from the cutting end 'of the drill, it follows that when the bit is once attached and the drill operated, the axial pressure or blows imparted to the shank to carry on the drilling" I.

will tend to drive the shank up the incline of the top face t of' the tongue, or what amounts to the same thing, to' drive the bit down the incline of the bottom of the groove 2, this action having the effect of tightening the bit on the shank instead of loosening the same, the bit being all the time forced toward the narrow end of the groove 2. At the same time the interlocking action between the members 3 and 6 serves to prevent displacement of the bit in the line of the axis of the shank. To detach the bit a slight tap delivered against the same at the narrow end of the groove 2 will force the bit across the shank axis toward the wide end of the groove as indicated by the arrow I in Fig. 2, thereby permitting ready withdrawal of the bit. While in the present embodiment of my invention I show the tongue 5 disposed on the bit and the groove 2 and recesses 3 on the shank, it would be fully within the spirit of my invention to reverse the positions of the members, forming-thetongue on the shank and the groove with its'recesses on the bit, The cross-sections of the groove and recesses may obviously be varied, my invention in no wise restricting me to the forms here shown. In the present embodiment of the invention, when the parts are assembled, the faces of the ofisets e, e, on

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- either side of the tongue rest against the faces h, k, on either side of the groove 2, the top face at of the tongue bearing against'the bottom of the groove. In the form here shown the lateral recesses 3 are disposed in a common plane transverse to the axis of the drill, necessitating a like disposition for the ribs 6; but it is obvious that I am not to be limited to this precise arrangement for these parts. stricted to ribs 6 made continuous as here shown, any equivalents thereof coming within the scope of the invention. The tool may in fact be changed in many particulars without involving a departure from the basic principle of the invention.

Having 'described my invention What I claim, is: I

I. In combination with a drill-bar or shank, a bit movable across the shank, taper= in transverse groove disposed across the axis of the drill and at an incline to said axis being formed on one of the members, the end faces of the memberon either side of the groove being parallel to the bottom of the groove, a corresponding tapering tongue and bounding offsets therefor-being formed on the opposite member and interlocking'with the formations on the first member, the direction of the taper of the groove and tongue aforesaid relatively to the cutting end of.

the drill being such as to cause the bit to tighten on the shank during the drilling operation, suitable recesses having parallel side walls leading from the groove aforesaid, and formations on the opposite member engaging said recesses, whereby the bit is positively secured-to the shank.

2. In combination with a drill-bar or shank, a bit movable across the axis of the shank, a tapering transverse groove dis- Neither do I wish to be rerestate posed across the axis of the drill and at an incline to said axis being formed on one of the members, the end faces of the member on either side of the groove being parallel to the bottom of the roove, a corresponding tapering tongue and bounding offsets therefor being for-med on the opposite member and interlocking with the formation on the first member, the direction of the taper of the tongue and groove aforesaid relatively to thecutting end of the drill .being such as to cause the bit to tighten on the shank in the drilling operation, recesses having parallel side walls leading from the sides of the grooves aforesaid, and suitable formations on the tongue for entering said recesses and positively securing the bit to the shank. I 3.- In combination with a drill-bar or shank, a bit movable across the shank, a transverse groove disposed across the axis of the shank at an incline to said axis and tapering on the sides in a general direction from the cutting end of the drill, lateral recesses having parallel side walls leading from the groove in a direction transverse to the axis of the shank, the faces of the

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