US1148760A - Rock-drill. - Google Patents

Description

c. A. DAWLEY.

ROCK DRILL.

APPLICATION FILED MAY13. 1908.

1 1 48,760, Patented Aug. 3, 1915.

4 SHEETS-SHEET l- Inventor:

A ttys 0. A. DAWLEY.

ROCK DRILL.

APPLICATION FILED MAYI3,1908.

Patented Aug. 3, 1915.

4 SHEETS-SHEET 2- Inventor:

C. A. DAWLEY.

ROCK DRILL.v

APPLICATION FILED MAY13| I908.

Patented Aug. 3, 1915.

4 SHEETS-SHEET 3- Inventor:

C. A-. DAWLEY.

ROCK DRILL.

APPLICATION FILED MAY,13,1908. LMSfiSO. Patented Aug. 3,1915.

' I i v 4 SHEETS-SHEET 4.

\m w est: Inventor;

CLARENCE A. DAWLEY, OF PLAINFIELD. NEW JERSEY, ASSIGNOR TO ING-ERSOLL-RAND COMPANY, A CORPORATION OF NEW JERSEY.

ROCK-DRILL.

Specification of Letters Patent.

Patented Aug. 3, 1915.

Application filed May 13, 1908. Serial No. 432,618.

v specification.

My invention relates to improvements in rock drills and comprises an improved pulsatory hammer drill and a motor driven compressor or pulsator operatively connected.

The object of my invention is to provide a pulsatory drill of high efliciency combined with lightness and portability.

I will now proceed to describe my invention with reference to the accompanying drawings illustrating one embodiment thereof.

In said drawings: Figure 1 shows an elevation of the drilling unit above described, both the drill proper and the pulsator being mounted on the same drill column; Fig. 2 shows a top view of the same parts so mounted; Fig. 3 is a detail sectional view illustrating the elastic buffer used in the supports of the compressor or pulsator; Fig. 4 shows the drill and compressor in elevation and without regard to their common mountings, the view being to that extent diagrammatic, both the drillcylinder and the pulsator cylinder being shown in section; Fig. 5 shows an end elevation of the pulsator, the compression cylinder thereof being shown sectioned transversely; Fig. 5 shows a transverse section of the cylinder through the axis of valve 21; Fig. 6 shows a transverse section of the drill cylinder on line 09-22 of Fig. 4; Fig. 6 shows a similar section on line g 3 of Fig. 4; Fig. 7 shows a detail axial section of the cylinder of the pulsator, and the cooperating parts,.the cylinder being shown in a different postion from that occupied in Fig. 1; Fig. 8 shows an axial section ofthe drill cylinder and of the feeding cylinder with which such drill cylinder is customarily provided. Fig. 9 shows a detail elevation of a hand type of tool, and also illustrates the use of one hose only connecting the tool and the pulsator. Fig. 10 shows a detail longitudinal section of-the front portion of a drill cylinder and associated parts, illus trating alternative means for supplying air or water-under pressure to the drill hole.

I will first describe, with especial reference to Figs. 48 inclusive, the construction of the pulsator and'the drill, and the way they operate; it being understood that the particular construction of such pulsator and drill herein illustrated is merely one of numerous possible constructions of combined pulsators and pulsating hammer rock drills, adapted for support upon a common column or the like as illustrated in Figs. 1 and 2. In these figures 1 designates the cylinder of the pneumatic tool (here supposed to be a rock drill of the hammer type), 2 the piston of such tool, 3 a combined rear cylinder head and handle, 4 a front cylinder head, 5 a drill steel, and 6 a guide bush- 1 ing orchuck therefor. The other parts within the cylinder 1 will be referred to hereafter.

7 designates the'compressor or pulsator cylinder, 8 the casing of the driving motor therefor, 9 the driving shaft of such motor, 10 a pinion onsaid shaft-and ll a gear, driven by such pinion and mounted on the crank shaft 12 of the compressor. Cylinder 7 of the compressor is mounted to oscillate upon trunnion 13, and its piston 14 is con nected by piston rod 15 to the crank pin 16 of shaft 12.

A flexible pipe 17 connects the rear end of compression cylinder 7 to the front end of drill cylinder 1. Another flexible pipe 18 connects the front end of the compression cylinder to the end of the drill cylinder, at a point over which the piston2 moves in its rearward travel.

In the wall of compression cylinder 7 there is a by-pass passage 19 serving to bypass around the piston when the latter is at the rear end of its stroke; and in the wall of said cylinder there is also another passage 20 serving to by-pas's the piston when the latteris at the front end of its stroke; this latter passage being controlled by a rotary valve 21 provided with an arm 22 pivoted to link 23 itself pivoted to a fixed point 24. It will be obvious that as the cylinder 7 oscillates this valve 21 will alternately open and close.

Referring again to the parts within tool cylinder 1, the upper end of the drill steel cup packing 28, between said annular rings, and surroundlng the striking'block'25', to"

form a tight joint. I may provide means for introducing water into the bore 29- of the drill steel, such means comprising a storage tank 30 which may contain water under pressure, and a valved pipe 31 connected to the cylinder 1 about opposite the cross-duct 32 in the ring 26.

Thereis. a narrow annular space between ring 26 and the portion of striking block 25 which that ring surrounds and in this portion of the striking block thereis a transverse'duct 33communicating with the longitudinal duct 34 itself in communication with the longitudinal duct 29 of the drill steel. It will be seen that water from pipe 31' entering the duct 32 of ring 26 will pass to this annular space between said ring and the striking block, and thence, flowing through said annular space, will enter the cross duct 33 and thence pass through duct 34 into the longitudinal duct 29 of the drill.

I also provide means for admitting air to this longitudinal duct 29 of the drill, to blow out the drill hole, such means comprising a passage 35 in the wall of cylinder 1, the port ofwhich is uncoveredby piston 2 when the latter is near the upper limit of its stroke. This passage 35 communicates with a' groove 36 in the wall of the cylinder, and the chuck 6 has in it ports 37 connecting this space 36 with an annular space surrounding the drill steel with which the cross duct 38 in the striking block 25 communicates. It will be seen that when the piston uncovers passage 35 air under pressure passes through said passage through groove 36 and ports 37 to the cross duct 38 and thence downward thrciugh the longitudinal duct 29 of the drill stee I Ring 27 seats against a shoulder 39 in the wall of cylinder 2; and cylinder head 4 being a screw head,'by screwing up said head the packing 28 may be compressed as desired to make a tight joint.

The operation of the apparatus as so far described is as follows: During the rearwardstroke of compression piston 14, air is compressed and forced through pipe 17 into cylinder 1 on the front side of its piston 2, forcing said piston backward; the air in rear of said piston 2 exhausting through pipe'18 into the front end of cylinder 7, un

til piston 2 over-rides the exhaust port 41 of cylinder 1, the piston 2 continuing to move backward against the cushion formed by the air imprisoned in the rear end of cylinder 1 until such cushion air is compressed sufficiently to overcome the inertia of said free piston 2 and so prevent it from striking the cylinder head. When compression piston 14 nears the rear end of its stroke by-pass passage 19 is opened by it, and thereby the pressures on the two sides of piston 14 are equalized, the pressure in the front end of cylin; der"? being raised considerably. The pressure in the front end of the drill cylinder1 being thus reduced sharply and being ward (piston 14 closes by-pass passage 19 shortly after it begins to move forward), piston 2 moves forward, and it is further v further reduced by the expansion of the air in rear of piston 14 as the latter-moves forimpelled in such motion by the compression of air in rear of it after it uncovers port-41, piston 2 being thereby caused to strike the striking block 25 andso communicate a blow to the drill. During its forward stroke the pressure in rear of said piston 14 will commonly fall slightly below the. atmosphere (owing to the equalization of pressures on the two sides of the piston which took place when said piston was near the rear limit of its stroke), whereupon a check valve 40 connected to the rear'e'nd of cylinder? will open, admitting air to said cylinder, the. air so admitted serving to compensate for leakage losses and for, air drawn off for various I ton 14 will again be equalized; though this equalization may be delayed somewhat if valve 21 be adjusted to open somewhat after piston 14 has uncovered the port of by-pass 20, as may be the case. This equalization furnishes to the rear end of. cylinder 7 before the beginning of the next compression stroke, a supply of air already compressed considerably above atmospheric pressure. During the compression stroke therefore, the pressure in the rear end of cylinder 7 in pipe 17, and in the front of cylinder 1, will be at all times above atmospheric pressure; and likewise the pressure in rear of piston 2 will be above atmospheric pressure, though of course it will be lower than the pressure in the front end of said cylinder 1. In other words, the unit operates on dense air, and therefore both the drill cylinder and piston and the compressor cylinder and piston may have much smaller cross sectional area than would be necessary if the working pressures varied considerably on both sides of atmospheric pressure. In fact,

except forl'eakage losses and the losses due to drawingoff air from-the front end of cylinder 7 for various purposes, the "mean pressure in the system would gradually rise to a high value, limited only by the clearance spaces. But since some leakage is unavoidable and must-be provided for, and since it is desirable to be able to'draw oif compressed air from the front end of cylinder 7 for various purposes, the mean pressure of the system will not be so high as would otherwise be the case but will still be considerably above atmosphere. That this mean pressure may be as high as deslred, however, to permit the desired reduction in size and weight of the parts of the drill and of the compressor, it is essential to keep the clearance spaces as small as possible, and to this end it is important to locate the compressor cylinder as close as possible to the drill cylinder and with very short connections between the compression cylinder and the drill cylinder, since these connections constitute a large portion of the unavoidable clearance space of the unit. Mounting both drill and compressor upon the same column, as shown in Figs. 1 and 2, permits the use of shorter flexible pipes 17 and 18 connecting the compressor and drill than could otherwise be used practically, and thus adds materially to the economy of the unit besides permitting the parts to be made smaller and lighter, and to operate at a higher speed, all of which conditions are necessary in order that the compressor and drill may be in practice mounted on a single column, as shown in Fig. 1.

Going back again to the consideration of the operation of the unit, it will be noted that when drill piston 2 nears the upper limit of its stroke it uncovers the port of passage 35, thus permitting air under pressure to pass through said passage and the ports 37 to the longitudinal duct 29 of the drill steel, for the urpose of blowing out the hole. Also, if the admission of water to the hole is desired, such admission may be efiected by means of pipe 31 connected to the cylinder 1 as previously described and also connected to the storage tank 30 containing a supply of water under pressure; and such pressure may be derived from the front end of cylinder 7 bymeans of a pipe 42.

Another convenient use for the compressed air which the compressor is capable of supplying in addition to that required for the reciprocation of the drill piston, is, the feeding forward of the drill cylinder. To this end, as shown particularly in F ig. 8, the drill cylinder may be provided with a hollow tubular rearward extension 44 arranged to work as a piston within a feeding cylinder 45 having a stuffing box 46 at its forward end. Air for feeding the drill is supplied through a pipe connection 47 connecting the tubular piston 44 with some convenient source of air under pressure, for example, the pipe 17 connecting the rear end of the compressor cylinder to the tool cylinder 1. In this pipe 47 I interpose a loaded check valve 48 comprising a ball plug 49 and a loading spring 50, the pressure exerted by this spring being regulable by means of an adjusting screw 51. It will be readily understood that compressed air supplied through pipe 47 exerts pressure in cylinder 45 on the hollow piston 44, tending to press cylinder 1 against the work.

For securing the drill to the column, this feeding cylinder 45 is arranged to be gripped bv a clamping collar 52 having a coned base 53 adapted to swivel in a clamping collar 54 adapted to be mounted adjustably upon the column 55 (Fig. 1) or upon an arm projecting from said column, or upon any other convenient means of support; and I provide this clamping collar 54 with a clam-ping device 56 for clamping said coned base in the corresponding recess of said clamping collar.

Referring to Figs. 1 and 2, showing a convenient method of mounting the drill and compressor upon the same mining column, 55 designates said column, 57 an arm adjustably clamped thereon and from which the compressor is hung, and 59 another arm adjustably clamped to said column and carrying the clamp 54 in which the feeding cvlinder 45 of the drill is held. The compressor is hung from arm 57 by means of brackets 60 with which the casing of the motor is provided; the compressor therefore hanging down from said arm 57 so that its ports to which flexible pipes 17 and 18 are connected, may be quite close to the corresponding ports of the drill cylinder, thus permitting the use of very short pipes 17 and 18, the desirability of which has already been described. This method of support also permits the drill to be moved toward and from the work to a considerable extent, without corresponding movement of the pulsator.

In the use of ordinary rock drills such drills are commonly arranged to be clamped upon columns or rods 55, which, according to the position they are to occupy, are called columns, or stoping bars, or shaft bars, etc.; the columnitself being substantially the same device in each case; and columns or bars and arms all having the same diameter; and sometimes the drill is mounted upon the column itself (this is ordinarily the case when the column is set horizontally or nearly so), while at other times the drill is mounted upon an arm clamped to the column or bar. Both compressor and drill of my pulsatory drill unit, may be mounted in each of these various ways, that is, either or both may be mounted on the column or bar itself, or upon an arm or arms projecting from the column or bar.

It is obviously unnecessary for me to illustrate these various methods of mounting the compressor and drill upon the same support, since, as already stated, the mounting of drills themselves in these various ways is a common expedient in the art. But it will be noted that, however the drill and thecompressor are so mounted, they are both always mou'ntedon the same sfupporting column or bar. under such conditions that itheir ports may be close together and that only very short flexible connections are required, and that both motor and drill may be moved to gether with their support, as a singleunit; wherein this unit differs fromformer pulsatory unitsheretofore used.

I have employed the term in as a term generic to mining columns, stoping bars, shaft bars and the like. I I My drill will ordinarily be mounted upon a'fiXed support, as illustrated in Figs. 1 and 2; but when made insmall sizes at least, it may be used as a hand tool, particularly when intended to be used for drilling vertical or nearly vertical holes. In such case, its rear head 3 may be provided with handles 62 as illustrated in Fig. 9. The use of an exhaust connection 18 is not absolutely required, though preferable; and in the case of the hand tool particularly, where extremely portability is desirable, such exhaust connection may. be omitted. This is illustrated in Fig. 9.

To eliminate so far as possible transmission of vibration from the drill to the compressor andparticularly to'themotor thereof, when said compressor and motor are mounted upon the same support as illustrated in Figs. 1 and 2,;Ico1nmonly provide the brackets 60 by which the compressor is ;hung, ,with elasticbufler rings 61 of rubber or othersuitable material.

Instead of employing a hollow drill steel air or water under pressure able means, as for example a casing surrounding the drill-steel, as illustrated in Fig. 10, wherein 62 designates such a casing, secured to the lower head 4; of the cylinder and surrounding the drill steel; the duct'35 in the wall of cylinder 1 in this casejextending to the end of the cylinder, there being in the bottom of the chuck 6 a groove 63 forming a continuation of'this duct 35, and serving to conduct the air to the aperture in the lower cylinder head through which the drill steelpasses. There .is sufiicient loose- Copies or this patent may be obtained for column here- I the pulsator cylinder at each having a cylinder and piston,

ness between the drill steel; and thesides of this 'hole to permit passage of the air from duct 35 into the casing 62, whence theair is conducted into the hole being drilled. Similarly, when water under pressure is tobe supplied to the drill hole, pipe 31may be pressure compression space, since, ow1ng to the greater clearance at the front end of cylinder 7, and for other reasons, the pressure attained during compression in the front end of 'saidcylinder will ordinarily be much lower than the pressure attained during compression into the rear end of said cylinder.

What I claim is:

1. The combination with a pulsatorytoo l having a cylinder andpiston, of a pulsator having. a cylinder and piston, one end of said pulsator cylinder being connected by a fluid conduit to one end ofthe tool cylinder, and. the other end of said pulsator cylinder being connected to the other end ofthe tool oining the ends of cylinder, and passages 1 end of the pulsatorpiston stroke to equalize the pressures therein. e p

2. The combination with a pulsatory tool of a pulsator having acylinder and piston, one end of said pulsator cylinder being connected by a fluid conduit to'on'e end of. the tool cylinder, and

the other end of said pulsator cylinder being connected to the other end of the tool cylinder, and passages bridging the pulsator piston and connecting the ends of the pulsator cylinder at each end of the pulsator piston stroke. I

In testimony whereof I have signed. this specification in the presence of two subscribing witnesses. CLARENCE A. DAWLEY. Witnesses? I p e H.,M, 1\/IARBLE, FRANK E. RAFFM N.

five cents each, by addressing the Commissioner of Patents, Washington, I). C. y i

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