US1740690A - Drilling mechanism - Google Patents

Description

Dec. 24, 1929. E. G. GARTIN DRILLING MECHANISM Filed Nov. 29, 1927 X rlllwfml li f l 1 mm @www ww ww www ,-Mwlwwgww- Patented Dec.'l 24, 1929 UNITED STATES PATENT OFFICE ELMER G. GARTIN, 0F CLAREMONT, NEW HAMPSHIRE, ASSIGNOR TO SULLIVAN MA- CHINERY COMPANY, A CORPORATION OF MASSACHUSETTS DRILLING MECHANISM Application led November 29, 1927. Serial No. 236,538.

This invention relates to drilling mechanisms and more particularly to the arrangement of the fluid distribution valve and fluid conducting passages in a hammer drill having a rear and rotation mechanism.

The invention has for its object to provide a generally improved design of a rock drilling mechanism. A more specific object is to locate the distribution valve in alinement with the motor and surrounding a rear piston extension and the rifle bar of a rotation mechanism. Another object is to conduct the motive fluid to the drill motor through the rear head member in a substantially straight line direct to the rear end of the cylinder. Still another object is to provide fluid actuated means for throwing the distribution valve controlled by the piston extension. Other objects and advantages will, however, hereinafter more fully appear.

In the accompanying drawings I have shown for purposes of illustration one form which my invention may assume in practice.

Fig. 1 is a central longitudinal section, in part diagrammatic, of a drilling mechanism embodying my invention.

Fig. 2 is a similar view showing the moving parts in a different position and broken off further back from the front end of the drilling mechanism.

Fig. 3 is a detail elevational view yof the distribution valve.

In this illustrative embodiment there is shown a pressure fluid actuated rock drill of the hammer type, generally designated 1, comprising a cylinder 2 having a bore 3 in which a hammer piston 4 is reciprocable. Mounted in the forward end of the cylinder is a buffer ring or cylinder head member 5 clamped between the forward end of the cylinder and a flange 6 on a chuck housing 7. Into an enlarged bore 8 in the rear end of the cylinder member 2 is fitted a cylinder head member l9 and between this cylinder head member and a ring 10 at the forward end of this cylinder extend usual side rods (not shown), the same being secured by any suitable means as lugs formed on the rear cylinder head and ring 10. Into the enlarged bore 8 there is secured in this instance a plurality of bushings or fluid conducting members 11 and 12, the former being preferably pressed into the bore 8 against the shoulder 13 formed between the bores 3 and 8. Between the bushing 12 and the rear cylinder head there is mounted the ratchet ring 14 of a ratchet and pawl rotation mechanism ot a usual construction. Rotation is transmitted from this ratchet mechanism through a rifle bar 15 to the piston 4 and further by means of the lugs 16 cooperating with the grooves 17 in a chuck nut 18 to the rotating chuck 19. It will of course be understood that a nonrotatable connection is provided between the chuck and drill steel, a part of which is shown at 19', so that the rotation of the ratchet mechanism is transmitted to the drill steel in the manner described.

The bushing 11 is provided with a reduced bore 20 adapted to receive and form a bearing for the larger portion of the rear piston extension 21. In the bushing 12 there are provided a plurality of bores 22 and 23 to receive the reduced spools 24 and 25 and enlarged spool 26 respectively of a fluid distribution valve. The still smaller bore 27 in the bushing 11 receives the reduced guiding extension 28 of the valve. It will be noted that the valve is coaxial with the piston extension 21 and is provided with the large central bore 29 in which the piston extension is ada ted to reciprocate. The valve chest is ormed principally by the bushing 12 and is provided with an enlarged annular groove 30 serving to conduct the live pressure fluid to the valve chest, and onv either side of an annular flange 31 defining one side of this groove, the walls of the bushings are for the main part hollow to form comparatively unrestricted fluid conducting passages, those leading to the valve chest being designated 32 and those leading from the valve chest to the rear end of the cylinder, 33. The valve chest provides two additional annular grooves 34 and 35, the former communicating with the front end of the cylinder through the passage 34 and the latter communicating with the atmosphere through the port 35 and being adapted to take care of part o f the exhaust :from the front l tle valve 42 which is illustrated in open poend of the cylinder. The piston extension 21 has formed on its surface an annular groove 36 and the bushing 11 is provided with a plurality of passages 37 adapted to communicate with the annular groove 36 to sup ly throwing pressure from the interior of t ie valve to the enlarged spool 26. The space formed by the bore 38 in which the enlarged spool 26 reciprocates is vented to the atmosphere through a restricted leak passage 39.

The rear end of the bushin 12 has an integral central web 40, provi ing by means of the bore 41, a bearing for the rotatable rifie bar. Motive fluid is adapted to be supplied through the rear cylinder head by means of a connection controlled by a throtsition. The rear head member is provided with an annular space 43 communicating.

with the throttle valve through the passage 44 and the ratchet ring has a plurality of passages 45 extending therethrough to conduct the motive fiuid to an annular space 46. The bushing member 12 provides a suitable number of passages 47 to suppl motive fluid from the annular space 46 to t e interior of the hollow valve member where it constantly acts on the end of the piston extension. A central exhaust port 48 in the cylinder wall communicates directly with the atmosphere and serves to exhaust the rear end of the cylinder and partially exhaust the front end of the cylinder. Cleansing fluid may be supplied to the drill steel throu h a central tu e 49 extending through the ri e bar and piston by means of some suitable connection as indicated at 50.

The operation of m drilling mechanism in view of the above escription of its construction will be readily apparent. lVith the arts in the position shown in Fig. 1 motive uid is conducted from the throttle valve 42 through the passages 44, 45 and 32 to the annular groove 30 and around the reduced portion of the distribution valve to the passages 33 where it acts on the rear of the piston 4 l which surrounds the piston extension. The

passages 47 sup ly motive fluid to the interior of the valve w ereby constant pressure acts on the rear end of the piston extension. The piston is thus forced forwardly until it de- 'vers a blow on the drill steel, the forward end of the cylinder being open to exhaust through the passage 34', grooves'34 and 35 and the passage 35. The rear end of the cylinder is exhausted through the port 48 as soon as said port is uncovered by the piston.

f On the forward stroke of the piston it will be position'shown in Fig. 2 due to live pressure acting bn the extreme end surface of the spool 24. The shifting of the valve serves to connect the forward end of the cylinder with the motive fluid supply through the annular grooves 30 and 34 and the passage 34. The effective area of the forward side of the piston being greater than the area of the end of the rear piston extension, the piston will be forced rearwardly. During the rearward stroke the annular recess 36 in the rear piston extension again serves as a means of communication between the passages 37 and the motive fiuid supply, whereupon the valve will be thrown to its opposite position, namely the position illustrated in Fig. 1, due to the fact that the effective area of the enlarged spool 26 exposed to live pressure is greater than the area of the end spool 24. The central port 48 serves to conduct most of the pressure fluid to the atmosphere directly and, after being cut off on the rearward stroke of the piston, the fluid which is thereby trapped will be compressed and cushion the piston. AS the motor continues to operate the same cycle of events as has just been described will simply be repeated as long as the throttle valve 42 is open.

As a result of my invention, it will be clear that I have provided a novel arrangement for the distribution valve which eliminates objectionable projections as are necessary when the Valve and valve chest is disposed on the side of the drill cylinder. It will also be evident that the direct connection between the rear end of the cylinder and motive fluid supply involving principally only straight passages will tend to make the blow of the piston more effective due to the fact that there is a minimum degree of restriction in the passages supplying the motive fiuid on the power stroke.

While I have in this application specifically described one form which my invention may assume in practice, it will be understood that this form of the same is shown for purposes of illustration and that the invention may be modified and embodied in various other forms without departing from its spirit or the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent is:

1. In a drilling apparatus, the combination tion of a drilling motor comprising a cylinder and piston reciprocable therein, rotation mechanism comprising a rotatable rifle bar extending into the rear end of the cylinder, sald piston having a rear extension surrounding said rifle bar', fluid distribution means for said motor comprising a reciprocatory valve surrounding said rifle bar and piston extension, and means for subjecting the end of said piston extension interiorly of said valve to live fluid pressure inclu `ing a constantly open connection between the same and a source of live pressure fluid. i

3. In a hammering motor, a cylinder, a piston reciprocable therein and having portions of different diameters, fluid distribution means for said motor including a tubular valve surrounding one of said portions of the piston, and means wholly controlled by a portion between the ends of said latter-portion for controlling the opposite movements of said valve.

4. In a drilling apparatus, the combination of a cylinder, a piston reciprocable therein and having an extension, rotation mechanism for rotating adrill steel including a rifle bar extending into the cylinder and cooperating with the extension on said piston, fluid distribution means for said cylinder and iston including a valve surrounding said ri e bar and piston extension, said valve having a surface exposed to constant pressure for actuating the same in one direction and an opposed surface of larger area, and means for subjecting said opposed surface to variable pressure for actuating the valve in the opposite direction.

5. In a drilling apparatus, the combination of a cylinder, a piston reciprocable therein and having a portion-of reduced diameter, and fluid distribution means for said irnotor including tubular longitudinally reciprocable valve surrounding said reduced portion, said reduced portion having fluid conducting means formed thereon adapted to control the actuation of said valve.

6. In a drilling apparatus, the combination of a cylinder and piston reciprocable therein and having an extension, rotation mechanism for rotating a drill steel including a riiie bar extending into the cylinder and cooperating with the extension on said piston, said extension having portions of different diameters, fluid distribution means for said cylinder and piston including a valve surrounding said rifle bar, and a passage positioned to communicate intermittently with live fluid pressure through a reduced portion of said extension, for controlling the actuation of said valve.

7 In a drilling apparatus, the combination of a cylinder, a piston reciprocable therein, a tail rod projecting rearwardly from said piston, fluid distribution means for said cylinder and piston including a valve surrounding said tail rod, said valve having a surface subjected to constant pressure for actuating the Valve in one direction and a larger opposed surface communicating With the atmosphere through arestricted leak passage, and means controlled by said tail rod for alternately subjecting said enlarged surface to live fluid pressure for actuating the valve -in the opposite direction.

8. In a drilling apparatus, the combination of a cylinder, a piston reciprocable therein and having a reduced rearward extension, means partially closing the rear end of said cylinder and telescopically receiving said piston extension, fluid distribution means for said motor comprising a fluid supply connection adjacent the rear end of said drilling apparatus, substantially straight longitudinal passages formed in said closing means leading from said fluid supply connection to the rear end of the cylinder, a fluid distribution valve reciprocable in said closing means for controlling said passages, and a constantly open fluid supply passage connecting said fluid supply connection with thc end of said piston extension.

9. In a drilling apparatus, a cylinder, a piston reciprocable therein and having an extension, rotation mechanism for a drill steel including a rifle bar extending longitudinally of the cylinder and cooperating with said piston extension, fluid distribution means including means for constantly subjecting the end of said extension to live motive fluid and a valve controlling fluid supply to opposite sides of said piston and surrounding said rifle bar and piston extension, and fluid pressure means for actuating said valve including a throwing passage controlled by said piston extension.

l0. In a drilling apparatus, a cylinder, a piston reciprocable therein and having a grooved extension, rotation mechanism for a drill steel including a rifle bar extending longitudinally of the cylinder and cooperating with said piston extension, fluid distribution means including a valve surrounding said rifle bar and piston extension, and fluid pressure means for actuating said valve including a throwing passage supplied with pressure fluid through the extension groove.

11. In a drilling apparatus, the combination of a drilling motor comprising a cylinder and a piston reciprocable therein, rotation mechanism comprising a rotatable rifle bar extending into the rear end of the cylinder, said piston having a rear extension surrounding said rifle bar, fluid distribution means for said motor comprising a reciprocatory valve surrounding said rifle bai' and piston extension, and common means for constantly subjecting the end of said piston extension interiorly of said Valve to live fluid pressure and for subjecting the end of said valve to pressure to bias it. toward one position.

12. In a drilling apparatus, the combina-.

tion of a cylinder, a piston reciprocable therein and having ahead and an extension, rota` tion mechanism for rotating a drill steel including a rifle bar extendin into the cylinder and cooperating with t e extension on said piston, uid distribution means for said cylinder and piston including a valve lsurrounding said rie bar and plston extension and operative to control Huid supply to opposite sides of said piston head, sa1d valve having a surfaceexposed to constant pressure for actuating the same in one direction and an opposed surface of larger area, and means for subjecting said opposed surface to variable pressure for actuating the valve in the opposite direction.

13. In a drilling apparatus, the combination of a cylinder, a piston reciprocable therein and having an extension, rotation mechanism for rotating a drill steel including a rifle bar extending into the cylinder and cooperating with the extension on said piston, fluid distribution means for said cylinder and piston including a longitudinally reciprocable valve surrounding said riie bar and piston extension, said valve having a surface exposed to constant pressure for actuating the same in one direction and an opposed surface of larger area, and means for subjecting said opposed surface to variable pressure for actuating the valve in the opposite direction.'

14. In a drilling apparatus, the combination of a cylinder, a iston reciprocable therein and having a hea and a portion of reduced diameter, and fluid distribution means for said motor including a tubular valve surrounding said reduced portion and operative to control luid supply to opposite sides of said iston head, sa1d reduced portion having uid conducting means formed thereon adapted to control'the actuation of said valve.

In testimony whereof I allix m si nature.

ELMER G. A TIN.

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