US2766011A - Drilling machines - Google Patents

Description

@ct. 9,1956 R. H. B. WINDER DRILLING MACHINES Filed June 3, 1952 3 Sheets-Sheet l t 9, 1956 R. H. B. WINDER 2,766,011

DRILLING MACHINES Filed June 3, 1952 3 Sheets-Sheet 2 I an zzzwp m m Oct. 9, 1956 R. H. B. WINDER DRILLING MACHINES 3 Sheets-Sheet 3 Filed June 5, 1952 INVENTOR RICHARD H. B. WINDER Av ATTORNEYS DRILLING MACHINES Richard Henry Bryan Winder, Cheltenham, England, as-

signor to National Coal Board, London, England, a corporation of Great Britain Application .iune 3, 1952, Serial No. 291,401 Claims priority, application Great Britain June 8, 19511 2 Claims. (Cl. 255-48) This invention relates to drilling or boring apparatus for use in making holes in earth, rock or coal or the like, as for example in making bore holes in a ripping face in coal mining or tunnelling operations.

One object of the invention is to provide an improved drilling or boring apparatus for drilling or boring in earth, rock or coal or the like, and according to the invention such a drilling or boring apparatus comprises a casing, an internal drill tube extending axially right through the length of the casing and adapted to hold a drilling bit at one end, means for imparting to said drill tube unidirectional intermittent rotary motion, and means whereby said drill tube can at will be caused to move axially relatively to said casing simultaneously with the rotary motion. The rotary motion may be provided by means of a pinion in rotary oscillation surrounding the drill tube, a reciprocating rack meshing with said pinion, and ratchet means transmitting motion in one direction from the pinion to the drill tube. Preferably the rack is reciprocated by means of a piston reciprocated by pulsating hydraulic pressure. In an advantageous construction a collar in rotary oscillation surrounds the drill tube, locking means prevent relative axial motion between the collar and the drill tube during rotation of the collar in one direction, and cam means can at will be caused to effect axial movement of the collar and drill tube relatively to the casing. The pinion and the collar may be rigidly connected to each other and the ratchet means and locking means are embodied in one device, for example a spring ratchet. There may be one or more cams on said collar and one or more cam followers engaging the cam or cams and mounted in the casing for rotary adjustment, the arrangement being such that by rotary adjustment of the cam follower or followers the drill tube may at will be caused to move axially forwards or backwards or to remain in a. substantially constant axial position relatively to the casing. In a particularly convenient arrangement a feed control is mounted so that it can be rotationally adjusted relatively to the casing and carries the cam follower or followers, and detent means are provided to hold the feed control in the rotational position to which it is adjusted. Advantageously a stream of fluid, for example water, is led through a space between the casing and the drill tube and back through the drill tube itself to flush away the drillings. A substantially tubular body may be movably mounted in the casing and is split and carries teeth or like projections at its external end, the external end portion being expandable so that the teeth or like projections can be caused to grip in a part of the hole which has been drilled by the apparatus and so hold the apparatus steady while further drilling is eifected. The casing may carry a fixed extension with a flared end and hydraulic pressure may be used to move the tubular body forward so that it is expanded by the flared end.

In the accompanying drawings an apparatus according to the invention is illustrated in somewhat diagrammatic form by way of example,

Figure 1 being a sectional side elevation of the apparatus;

Figure 2 a section on the line II-II of Figure 1;

Figure 3 a view of a detail;

Figure 4 is a bottom plan view of the collar and showing the cam means provided thereon;

Figure 5 is a cross-sectional view taken on line 5-5 of Figure 4;

Figure 6 is a cross sectional view of the tube and casing showing the ratchet means for preventing rotation of the tube relative to the casing during one movement of the collar;

Figure 7 is a longitudinal detailed sectional view of the outer end portion of the drill tube, and,

Figure 8 is a cross-sectional view taken on line 88 of Figure l and showing the mounting arrangement of the spring ratchet which drivingly connects the drill tube to the collar.

Referring to the said drawings, the apparatus comprises a casing 12 having a transverse cylinder 2 in which a piston 1 is given a rapid reciprocating motion by means of a pulsating hydraulic pressure obtained for example from a swash plate pump, a compression spring 3 being provided in the cylinder 2 to return the piston 1 when the hydraulic pressure decreases.

Extending axially right through the length of the casing 12 is a drill tube 10 which is adapted to hold at one end a drilling bit 31 as shown in Figure 3. A collar 6 surrounds the drill tube 10 and carries an integral toothed pinion 5 which meshes with a rack 4 formed integrally with the piston 1. A conventional coil spring ratchet 7 is secured within the collar 6, and as the piston reciprocates and causes the rotary oscillation of the pinion 5 and collar 6 the coils of the spring ratchet '7 alternately tighten and grip the drill tube 10 and then unwind to release the tube 10 so there is imparted to the said drill tube a rapid unidirectional intermittent rotary motion, this motion being clockwise in the arrangement as illustrated in Figure 2. One end of the spring ratchet is anchored or attached to the collar. For example as shown in Figure 8, the driving end of the spring ratchet 7 is secured to the collar by means of a split collet 4t) driven into a tapered bore 41 in the collar 6. The spring ratchet frictionally surrounds the tube. The drill tube remains stationary during anti-clockwise rotation of the pinion 5 and collar 6 either because of the friction of the drill bit or by means of a second ratchet 36 arranged at a convenient position within the casing 12. The ratchet 36 is a conventional ball ratchet as shown in Figure 6. The collar 6 is capable of axial motion relatively to the casing 12. At its forward end the collar 6 is acted upon by a compression return spring 16 the force of which is transmitted through a collar 14 and ball bearing 13. At its rear end the collar 6 is provided with two feed cams 11 each of which is engaged by a cam follower roller 9 mounted in a feed control 3. The feed control 8 is capable of being rotated within the casing 12 in which it is held by means of a screw-threaded collar 32. Un desired rotation of the feed control 8 is prevented by a detent ball 33 which engages in anyone of a series of recesses in the feed control 8 against which it is pressed by means of a compression spring 34 of which the upper end bears against a screw-threaded plug 35. To permit rotation of the feed control against the action of the detent ball 33, the part of the feed control extending outside the collar 32 is either knurled for manual operation or made of non-circular section to receive a wrench or handle. The coils of the spring ratchet 7 are arranged to be a friction fit on the outside of the drill tube 10 and are attached to the collar 6 by one end as shown in Figure 8. When the collar 6 is rotated in the direction which tends to tighten the coils of spring ratchet 7, the initial frictional grip is amplified so that tube 10 is gripped. When the collar is rotated in the opposite direction, the coils of the spinrg ratchet 7 tend to open, and the frictional grip is so reduced as to allow slip between spring ratchet 7 and drill tube 10 to occur. In certain cases, it may be necessary to provide additional means such as the second ratchet 36 to prevent the drill tube 10 from rotating backwards during reverse rotation of the collar 6, due to the slight frictional drag of the spring ratchet 7 slipping on the drill tube 10.

According to the position of the feed control 8, the feed cams 11 can be caused at will to give rise to forward or rearward axial movement of the drill tube 10 relatively to the casing 12 simultaneously with the rotary motion of the drill tube, or to permit the drill tube 10 to remain in a substantially constant axial position relatively to the casing. The collar 6 oscillates through approximately /6 of a revolution. During clockwise rotation of the collar 6 as viewed in Figures 2 and 4 the spring ratchet 7 locks the drill tube 10 to the collar 6 so that the drill tube must take part in any axial and rotary motion of the collar 6. In one position of the feed control 8 and cam follower rollers 9 the low points of the feed earns 11 engage the rollers 9 at the moment when the clockwise motion of the collar 6 is commenced, and subsequently during the clockwise rotation of the collar 6 the rollers 9 act on parts of the cams 11 indicated by the arrows b in Figures 4 and 5 such that the collar 6 and the drill tube 10 are moved forward relatively to the casing 12; during the anti-clockwise motion the ratchet 7 releases the drill tube from the collar 6 and the latter moves rearwardly under the action of the spring 16. With the feed control 8 and cam follower rollers 9 set to a different position, the high points of the feed cams 11 engage the rollers 9 as the clockwise motion of the collar 6 commences, and during clockwise motion the rollers 9 act on parts of the earns 11 as indicated by the arrow in Figures 4 and such that the collar 6 moves rearwardly under the action of the spring 16 and carries with it the drill tube 10; during anti-clockwise rotation of the collar 6 the ratchet 7 releases the drill tube 10 and the feed cams 11 force the collar 6 forwards against the action of the spring 16. With the feed control 3 and cam follower rollers 9 set in an intermediate position the rollers 9 act on parts of the cams 11 as indicated by the arrows a in Figures 4 and 5 so that there is substantially no resultant axial motion of the drill tube 10 relatively to the casing 12 but only a small axial reciprocation thereof with the collar 6.

At its forward end the casing 12 is provided with a fixed tubular extension 18 having a flared end 19. Surrounding the extension 18 is a slidable tubular body 20 mitted through an inlet pipe 25 to an annular chamber 21 the body 20 is forced forwards with respect to the casing 12 and its split end is caused to expand by the flared end 19 of the extension 18 so that the teeth 24 grip the wall of the bore hole.

Water under pressure may also be admitted through an inlet pipe 26 whence it passes along an annular space between the drill tube 10 and the tubular extension 18, through the space 27 (Figure 3) between the Wall 28 of the bore hole and drill tube 10 and so back through the drill tube 10 flushing away the drillings. A water seal 29 prevents water flowing backwards in the casing 12, and a water seal 30 near the end of the tubular body prevents water flowing backwards in the bore hole.

The supply of flushing water and water under pressure through the pipes and 26 may both be drawn from the same source as that which supplies the pulsating hydraulic pressure operating on the piston 1r Additional lengths of hollow drill tube 10 may be used as necessary to lengthen the drill tube.

Instead of or in addition to being held by the teeth 24, the casing may be held in a rig.

I claim:

1. In an apparatus for drilling in earth, rock, coal and the like, the combination of a casing having an open end, a drill tube axially disposed in the casing and extending through the open end, a collar surrounding the drill tube in spaced relation therewith and mounted for rotational and axial movement within the casing, a piston carried by the casing and arranged transversely thereof for axial reciprocation, interengaging means on said piston and on said collar for producing rotary oscillation of the collar as the piston is reciprocated, a coil spring surrounding and frictionally engaging the tube within the collar and fixed to the collar, said coil spring forming a spring ratchet means to frictionally grip the tube and lock the tube and the collar for common rotation when the collar rotates in one direction and to release the tube when the collar rotates in the other direction whereby the tube is given a unidirectional rotary movement relative to the casing, and cooperating means on said casing and on the collar operative upon the rotation of the collar and frictional locking of the tube with the collar to cause the collar and the drill tube to move axially, whereby the drill tube is given an axial movement relative to the casing simultaneously with its rotary movement.

2. The combination of claim 1, wherein said cooperating means includes cam means provided on the collar and a member adjustably supported by the casing and having roller means on which the cam means engages, said member being adjustable to position the rollers in selected relation to the cam means to control the axial movement of the collar.

References Cited in the file of this patent UNITED STATES PATENTS 425,471 Toense Apr. 15, 1890 953,855 Nixon Apr. 5, 1910 953,969 Nixon Apr. 5, 1910 2,299,881 Demo Oct. 27, 1942 2,524,091 Von Zimmermann Oct. 3, 1950

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