US2257418A

US2257418A - Detachable bit rock drill

Info

Publication number: US2257418A
Application number: US199200A
Authority: US
Inventors: Knutson Gustave
Original assignee: Internat Detachable Bits & Equ
Current assignee: Internat Detachable Bits & Equ; International Detachable Bits & Equipment Ltd
Priority date: 1938-03-31
Filing date: 1938-03-31
Publication date: 1941-09-30
Anticipated expiration: 1958-09-30
Also published as: GB522193A

Description

Patentecl Sept. 30, 1941 DETCHABLE BIT ROCK DRLL Gusta.ve Knutson, South Porcupine, Ontario, Canada, assignor, by mesne assignments, to

International Detachable Bits & Equipment, Limited, Timniins, Ontario, Canada, a corporation of Ontario, Canada Applieation March 31, 1938, SerialN0. 199,200

Claims.

My invention relates to improvements in detachable bit rock dril1s particularly of the type wherein the connecton between bit and shank comprses a dovetail tongue on one member inseitable into a dovetail slot in the other member, and. an object of the invention is to devise en improved form of dovetail connection between bt andshank which will tend to 1etain the bit in axia1 aiignmeht vvith the shank during drilling end obviate the liability of its being deflected rom its course due to siips and other changes in rock formation.

A- furtherobject of the inventon is the previsin of means on the dovetail tongue engageable with an abutment in the dovetail slot for further assisting in keeping the bit in axia1 algnment with the shank as it can only be detached from such shank trom theside from which it has been inserted.

With the above and other objects in view which will hereinafter appear as the specification proceeds my invention, in ts preferred embodment, consists of the construction en as hereinafter more particularly descrbed and illustreited in the mccompanying drawing in which:

is applied to the shank in axial alignment and the dri1l nserted into a hole in the rock which may have been previously begun by a starter dri11 or other dri1l, the axes of bit and shank Wil1 remain substantially coincident as the bit cannot s1ide sidewise relatively to the shank unless its axis is disposed angularly to the shank. Such augu- 1arity is obvously prevented by the wa1l of the hole being drilled.

Referring to the specific construction of my invention as illustrated in the drawing, the shank l provided with the usual axia1 Water orfice 2 therethrough has a. cupped bt engaging end 3 with a dmetrical slot 4 of dovetail cross-section extending thereacross.

longitudinal verticai section conforming with the Fig. 1 is a. side view of a, rock dril1 constructed according to my invention.

Fig. 2 is a. similar view taken at right angles to Fig. 1.

Fig. 3 is a side view (partly in secton) showing the detachable bit partially inserted into or detache-d from the shank.

Fg. 4 is a vertical section of the shank taken on the line 4-4 (Fig. 5).

Fig. 5 is a, plan view of the snank, end Fgs6 and 7 are side views of the detachable bit teken at right ang1es to each other.

Like characters of reference indicate correspondng parts in the different views of the drawng. 1 l -I1XO it has been the practice in dovetail connections betweer bit and snacnk to have the dovetail slot and dovetail tongue extend straight across shank -zmd bit respectively at substantilly right angles to their axes. 'Ihe disadvantage of such construction is that the dovetai1 tongue, bing lateraliy movable in the dovetail slot, tends to permit the bit to get out of axial algnment With the shank during drilling and to be deflected frem ts course.

According to my invention, I obviate this disadvantage by making the dovetail tongue substantially arcuate in longitudinal vertica1 section and the dovetail slot a1so correspondingly arcuate curvature of the eupped end 3. Arcua.te

grooves

5 and 6 are provided respectively in each side wa11 of the slot 4 in the vicinity of its arcuate roof and such grooves areopposedly positioned in the side wa11s of the slot so as to extend fromtheir ends to substantialiy emid-point in their 1ength. The detachable bit provded with cutters 8 and an axia1 water orifice 9 has a domed upper portion l0 corresponding to the cupped end 3 of the shank into which it is adapted to be received and a diametrically extending tongue U of dovetail cross-section corresponding to that of the dovetail slot 4 inthe shank surmounts the domed upper portion II) of the bit, such tongue being arcuate in iongitudinal vertical section corresponding with the curvature of the slot 4 in the shank. A- projection 12 is provided en e sidewall of the tongue II at its mid-point and is receivable into a groove 5 or 0 in the wa1ls of the slot 4 when the bit is applied to the shank.

In appiying the bit to the shank, its axis is dsposed at an angle to the axs of the shank as illustrated in Fig. 3 and the end of the tongue II is inserted into the slot 4. Simultaneously the projection 12 is inserted into the

groeve

5 or 6 depending from which side of the shank the tongne is introduced. Then by sliding the bt laterally, the tongue II foliows the slot 4 until the axis of the bit becoms coincident with the axis of the shank. In such postion the projection I2 abuts aganst the end Of the

groove

5 or 6 and further movement of the hit in such direction is prevented. The bit. can now only be moved in a reverse direction to the direction in which it has been inserted in the shank.

The cupped end 3 of the shank I abuts the domed portion 10 of the bit and consequently a, rigid detachable connection between bit and.

in the same secton. Consequently, when the bit shank is consttuted.

Such slot is arcuate in From the above desoription t will be apparent that I have devised a detachable bt drill in which the dovetail connecton between bit and shank is suchthat in drillng, lateral movement of the former relatively to the latter is obviated by the provision of the arcuate tongue and arcuate slot assisted by the projection on the tongue abuttng the end of a groove in one sde wa1l of the arcuate slot.

Although I have illustrated and described the arcuate tongue as being on the bit and the arcuate slot in the end of the shank these elements may, if desired, be reversed. l

What I claim as my invention is:

1. In a detachable bit rock drill, the combination with a shank member and detachable bit member, of a detachable connection between bit and shank members comprising a. diametrical tongue of dovetail cross-section and arcuate in longitudinal vertical seotion on the end of one of the members receivable into a correspondingly shaped slot in the end of the other member.

2. In a. detachable bit rock dril1, the combination with a shank member and detachabie bt member, of a detachable connection betweenbit and Shank members comprising a diameizrical tongue of dovetail cross-section and arcuate in longitudinal vertical secton on the end of one of the members receivable into a. correspondngly V shaped slot in the end of the other member, and

coaoting means between tongue and slot for preventing the tongue being inserted into the slot further than a postion in which the axes of bit and shank are coincident.

3. In a detachable bit rock drill, the combinaton wth a shank member and detachable bit member, of a detachable conhection between bit and shank members Comprising a, diametrical tongue of dovetailcross-section and arcuate in longitudinal vertical section on the end of one of the members receivable into a correspondingly shaped slot in the end of the other member, and a projection on a side wall of the tongue insertab1e into an arcuate groeve in a side wall of the slot, said groove terminating at a mid-poimt in the length of the slot.

4. A detachabie bit rock dri1l comprising a shank havng a diametrical slot of dovetail crosssection in its bit engaging end, said slot being arcuate in longitudinal vertical seetion, and a detachable Dit having a diametrcal tongue of dovetail cross-section on its shank engaging end, said tongue being arcuate in longtudinal vertcal section correspndng to the curvature of the slot into which it is inserted.

5. A detaichable bit rock dri1l comprising a shank having a) diametrcal slot of dovetal crosssection inits bit engaging end, said slot being. arcuate in 1ongitudinal vertcal section, and a detachable bit having a dametrical tongue of dovetail cross-section on its shank engaging end, said tween bit and shank for preventing the insertion of the tongue into the slot past a position in which the axes of bit and shank are coincident.

6. A detachable bit rock dri1l comprisng a shank having a dametrical slot of dovetail crosssection in its bit engaging end, saidslot being arcuate in longitudinal vertical section, a detachab1e bit having a diametrical tongue of dovetal cross-secton on its shank engaging end, said ongue beng arcuate in longitudinal vertical secton corresponding to the curvature of the slot into which it is inserted, and 2, projecton on a side WaQ1l of the tongue insertable in an arcuate 'groove in a. side wa11 of the slot, said groove terminating at a mid-point in the length of the slot.

dmetrical slot of arcuate cross-section in such tongue being arcuate in longitudinal vertical section corresponding to the curvature of the slot into which it is inserted, and coactingmeans beend, said slot beng arcuate in longitudinal vertica.l section, 2. 'detachable bit; having a domed portion receivable into the cupped end of the shank, and a diametrcal tongue of dovetail cross-section and arcuate in longitudinal vertica.l section corresponding to the curvature of the slot in the shank int0 whch t is receivable, and coacting mans between bit and shank for preventing the insertion of the tongue into the slot past a position in which the axes of bit and shank are coincident. 9. A detachable bit rock drill comprising a shank witha cupped bit engaging end and a diametrical slot of arcua te cross-section. in such end, said slot being arcuate in longitudinal vertica1 secton, adetachable bit h aving a. domed portion recevable into the cupped end of the shank, a diametrical tongue of dovetail crosssection and arcuate in longitudinal vertical section correspondng to the curvature of the slot in the shank into which it is receivable, and a, projection en a side wall of the tongue insertabl in an arcuate groove in a Sde Wa11 of the slot, said groove terminatng at a. mid-point in the length of the slot.

10. In a rock-drlng combination, a shank member havng a concave end portion curved on a radius having a center on the axs of said shank and provided with a diametric dovetail slot curved on a radius havng a center coinciding wigh said first named center, and a bit member having an end portion and.diametric dovetail portion curved complementally to, and adapted to engage, respectively, sad curved shank end and dovetail slot.

GUSTAVE KNUTSON.