US1251323A - Coal-drill. - Google Patents

Description

D. S. BACHELDER..

COAL DRILL.

APPLICATION FILED m1; l9, I916.

1,251,323. mm ne. 25,1 17;

ture opens.

UNITED STATES PATENT OFFICE.

DAVID S. BACHELDER, OF TILDEN, ILLINOIS, ASSIGNOR 0F ONE-HALF TO JAMES CONNOR, OI TILDEN, ILLINOIS.

COAL-DRILL.

ran ed that the chips or bits of coal or rockas t ey are cut from the bed are guickly removetffrom the bore which the rill struc- With this object in view the drill com-, prises a head having at one end a socket by means of which it maybe attached to a drill rod in a usual manner; the said head having atits other end portion openings one positioned at the center of the head and adapted to receive thecenter drill bit and the other openings arranged. one at 'each side of the said central openingand adapted to receive the shank of the side'drill bits. The said head is provided at its'exterior with spirally disposed spaced ribs the outer edges of which are relatively sharp and the head between the said ribs is curvedor concaved thereby eliminating angles and sharp corners which would interfere with the free 'passag'eof the drills dust along the said ribs as the said material is being forced from the bore which is opened by the drill structure. The side drill bits have their outer or forward end portions spiral twisted to conform substantially with the spiral disposition or twist of the ribs located at the exterior of the head and the said side drill bits are provided at their forward ends with cutting edges which are substantially radially disposed with relation to the axis of the head.

In the accompanying drawing d 1 is a side elevation of the coal Fig. 2 is a longitudinal sectional view of the same;

Fi 3 is a similar view out on a plane at a rig t angle to that on which the section of 2 is cut;

ig. 4 is a transverse sectional view out on the line 4-4 of Fig. 1;

'" Specification of Letters Patent. Patented Deb. 25,1917.

Application and April 19, 1916. Serial No. 92,191.

Fig. 5 is a similar view out on the line 5 -5otFig.1. i The coal drill comprises a head 1 having at one end a socket 2 adapted to receive a rod whereby the said head may be rotated in a usual manner. Any suitable means may be provided for securing the head upon the rod in a manner which will permit the head to be removed from the rod when desired.

The head 1 is provided at its forward end with a central non-circular opening 3, the inner end of which communicates with the inner end of the socket 2. A center drill bit 4 is provided with a shank 5 which fits snuglyin the opening 3 and a set screw 6 passes transversely through the side of the head 1 and bears at its inner end against the side of the shank 5 and serves as means for .detachably holding the bit 4 in the opening 'gular or non-circulanin transverse -section. Side drill bits. 10 are )rovided with non-circular shanks 11 w ich fit snugly in the openings '8 and the inner ends of the said shanks 11 are receivedin the slots 9. The outer portions of the side drill bits 10 are spirally twisted as at 12 and the said bits 10 are provided at their outer or. forward ends with cutting edges 13 wh. -h are disposed approximately radially with relation to the axis of the head 1 and at acute angles with relation to the said axis. Set screws 14 pass through the head '1 and hear at their inner ends against the shank 95 11 of the side bit 10 and serve as means for detachably holding he shanks in the openbetween the said ribs 15 is concaved or curved whereby the head 1 between the said ribs 15 is devoid of sharp corners or angles which would interfere with the passage of material through the space between the ad'- jacent ribs 15.

In operation the center drill bit 4 is positionedagainst relativelyhard material as for instance rock or slate and. the head 1 is The center rotated in the usual manner. drill bit 4: penetrates into thesaid hard material and the chips or dust cut by the bit 4 is taken up by the twisted portions 12 ofthe side drill bit 10 and moved into the spaces between the ribs 15 which in turn operate upon thesaid material to'work the sametoward that end of the head 1 which is connected with the rod which operates the same at the socket 2.

In view of the fact that the ribs 15 are sharp at-their outer edges and the head 1 between the ribs isdevoid of an les or sharp corners there are'no spaces in w ich the fine material may accumulate and interfere with the operation of the drill or the, free passage, of the chips from the bore which is being cut by the drill. a

Following the bit 4' the cutting edges 13 of the side drill bits 10 enter thematerial.

and enlarge the bore and thechips which are cut from the solid rock or coal by the cutting-edges 13 of the sidebits 10 are moved along the twisted portions of the said side bits 10 and pass into the spaces between the ribs 15 which in turn operate upon the said material to move it alon the head 1 and -eject it-from the head at the ends thereof which is provided with the socket 2.

VV hen 1t isdesired to sharpenthe bits 4 and 10. or to renew the same the set" screw .6 is removed from the head 10 whereb the bit 4 may be slipped out of the openlng3 and the set screws 14' are removed from against the shankll whereby the bits 10 may be remoi'ed from the openings 8. ,In the event that the shanks 11 stick in the openings 8 an implement may be inserted through the slots 9 and against the inner ends of the/said shanks for forcing the shanks out-of the openings 8.

With the drill, such as described herein, it is found the coal and balls of sulfur lodged therein are out very rapidly and evenly and the speed at which the hole is formed correspondinglfi' increased. At the same time, it is foundt at the drill turns very lightly and conjunction with the accompanyin the removal of particles of dust from the hole and thereby prevent interference to' the proper operation of the drill from this cause.

Furthermore the material of. which the head is composed is so disposed about the open--- ings 8 that-the presence of the said openin does notweaken t'he'head hence they may extended for a considerable distance in the head and in view of the fact that they are comparatively long, they may retain drill bits having long shanks. Thesebits having long shanks are susceptible of being sharpened many times before their shanks are ren dered too .short to be securely held in the o enin The sharpening of the bits is e ecte .by flattening portions of their shanks on the horn-of an anvil, and peening down their cutting edges "with a hammer. Hence the bits may be-kept in proper condition without the use of special or expensive sharpenin machines or devices. 7 i 'From t e foregoing description taken in drawing it will be seen that a coal drill 0 sim 1e and durable structure is provided and t at" the. same will efiiciently operate to operi 1a 5 I bore "in solid-goal or rock and remove the chips or cut material from the said bore promptly during the operation of forming the bore in the said solid material.

Havin claimed 1s:-'--' t I A drill comprising ahead provided with openings which extend longitudinally of the head and parallel therewith and adapted to receivedrill bits, said openings at their inner ends terminating in slots. which open at the sides of the head, 'spaced ribs acuminatedin' transverse section and spirally disposed along the periphery of the head at the opposite edges of the slots, the surfaces of the material of the head between the ribs being concavedly curved longitudinally of the head and (wnvexedly curved transversely thereof from edge to edge of the adjacent ribs and the said surfaces intersecting each other at the keen edges of the ribs.

In testimony whereof I aflix my signature.

DAVID s. BACHELDER.

described the invention what is head at the opposite sides of the axis of the

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