US1195478A - Rock-drill - Google Patents

Description

M. A. KNAPP.

ROCK DRILL.

' APPLICATION man sEPT.5. 191|.

Patented Ang. 22, 1916.

3 SHEETS-SHEET ll m m2 MIN MQ hlw lumi!!- mv O E w?. um Mm, w 9 hH x rv 1... A, P. NQ ...9 Hm MH W/TNESSES:

M. A. KNAPP.

ROCK DRILL.

APPLlcATloN man sEPLS. 191|.V

Emmmmmw mmbw www lllr @UEM By Mr L TTOR/VEKS Patented Aug. 22, 1916.

llllllllllllnlluilllllllllllllillull nllililnn nl n IIN. llllllllllllllllllllllllllllllllllllllllllllllllllllll nu .--.-.----.-......-...--.-...Wm- --.l V :mw A N. LW Jim www M. A. KNAPP.

ROCK DRILL.

FFIQE.

MOSES ARTHUR KNAPP, OF OAKLAND, CALIFORNIA.

ROCK-DRILL.

Application filed September 5, 1911.

To all LU/0m t may concern:

Be it known that I, MOSES ARTHUR KNAPP, a citizen of the United States, and a resident of Oakland, in the county of Alameda and State of California, have invented certain new and useful Improvements in Rock-Drills, of which the following is a specification.

The invention relates to rock drills and especially to rock drills of the hammer type which are operated by a series of sharp percussive blows from a hammer.

The object of the invention is to provide a rock drill for drilling long cylindrical holes from confined spaces in underground workings by means of rapid cutting percussive drilling machines.

A further object of the invention is to provide an improved means for rotating the drill bit as it passes through the material being cut.

Another object of the invention is to lprovide means for conveying water, or water and compressed air to the face of the drill bit, to clear the hole and remove the material as it is cut by the drill bit.

Another object of the invention is to provide a drilling apparatus which will cut deep, straight cylindrical holes in rock without diminishing the size of the hole with increasing depth.

This drill possesses other advantageous features, which, with the foregoing will be set forth at length in the following description, where I shall outline in full, that form of embodiment of the invention which I have selected for illustration in the drawings accompanying and forming part of the present. specification. The novelty of the invention will be included in the claims succeeding said description. From this it will be apparent that I- do not restrict myself to the showing made by such drawings and descriptions as I may adopt many variations within the scope of my invention as eX- pressed in said claims.

My invention may be briefly stated to consist in a drilling device in which the impact of a hammer of the percussion type, operating to apply a series of blows in rapid succession is transferred to the drill bit through a series of rods arranged between the hammer and the drill bit, so that the maximum blow is transmitted t0 the drill bit, The

Specification of Letters Fatent.

Patented Aug. 22, 1916.

Serial No. 647,506.

rods are generally alined by means of a tube provided on its inner end with means for detachably connecting the drill bit thereto, so that a rotation of the tube causes a similar rotation of the drill bit. Means are also provided for rotating the tube either by hand or power, whichever is the most desirable under the circumstances of operation. Provision is also made for introducing a stream of water into the outer end of the tube, and for causing this water to pass through the drill bit, and to its cutting face. I also employ a novel drill bit particularly adapted for use with' the drilling apparatus which drills a straight hole of constant diameter.

Referring to the drawings: Figure 1 is an elevation, partly in section of a-power operated drilling machine provided with means for introducing water into the tube, means for rotating the tube, and means for advancing the tube as the drill bit penetrates the rock, the machine being arranged in position for drilling a horizontal hole. Fig. 2 is a cross section through the drilling machine taken on the line -:c Fig. 1. Fig. 3 is a longitudinal section through the power operated device for rotating the tube, and for moving it longitudinally. Fig. 4: is a cross section through the power operated mechanism shown in Fig. 8. Fig. 5 is a longitudinal sectional detail of an end of the mechanism for advancing the tube into the hole. Fig. 6 is a longitudinal section through the drilling machine showing the tube and one of the rods in position. Figs. 7 and 8 are longitudinal sections through the tube showing the same forward in sections and having the rods arranged therein, the rods in the two figures being of dierent lengths. Fig. 9 is a section through the inner end of the tube and drill bit showing the passage therethrough. Fig. 10 is a view of the end of the tube and the drill bit, showing the method of detachably connecting the two. Fig. 11 is a detail of the end of one of the sections forming the tube, showing the means of connecting the sections together and of supporting the impact rods centrally therein. Fig. 12 is a detail of the outer end of the drill bit showing the means employed for causing the water surrounding the rods to pass through the drill bit. Figs. 13 to 19 inclusive are cross sec- 60 energy at each contact of the series.

tions taken through various parts of the drilling machine, the tube and the drill bit. Fig. 13 is taken on line zr-a, Fig. 6; Fig. 14 online b-, Fig. 6; Fig. 15 on line @-0,

Fig. 6; Fig. 16 on the line cZ-Z, Fig. 6; Fig.

17 on line e-e, Fig. 12; Fig. 18 on line f-', Fig. and Fig. 19 on the line g-g Fig. 10. Fig. 20 is a cross section of the drilling machine taken through the ring' for con- 10 necting the hammer cylinder to the advancing means. Fig. 21'is a sectional detail of the piston which operates to rotate the tube. Fig. 22 is a longitudinal section through the drill bit. Fig. 23 is an external view of the drill bit showing the longitudinal groove therein Fig. 211 is an end view of the drill bit.

The drilling engine may be of any of the various hammer types in general use for applying to the drill bit percussional impulses of high frequency, that shown in the drawings consisting of a cylinder 2 in which is arranged the reciprocating hammer 3 which imparts the blows to the tappet 4. Power 25 is supplied in the form of compressed air or steam through the conductor 5. Arranged adjacent to the tappet 41 is the chuck 6 which is adapted to receive the tube 7 which extends into the hole being drilled.

A series of separate rods 8 are arranged within the tube, which is preferably formed of sections coupled together so that, as .the drill bit proceeds into the hole, more sections may be added. lThese rods 8 extend from the drill rbit 9 to a position in close relation to the tappet 4, oi` the hammer 3, so that the impact of the tappet or hammer is transferred through the various rods to the drill bit. Hereinafter, wherever the blow of the hammer is referred to, it is to be understood that such blow may be transmitted directly to the rod series, or may be transmitted thereto through the tappet.

According to the laws of analytical mechanics, a perfectly elastic body striking another of equal weight transmits its kinetic energy to the latter without loss. My experiments have shown that in the case of tempered steel bars this law is true when the bars are of equal length or approximately so. A 20% difference in weight of the bars causes only a slight loss at impact if the equality of length is preserved. I have found that a row of steel bars, of approximately equal length and weight, placed production of sound and heat waves. If the rods are not of equal length, the tendency to separation with consequent loss of energy will be prevented by the provision of means to hold the rods together. Employing this principle in a rock drill, I am enabled to carry the effect of a blow from the hammer or tappet through the intervening separate rods to the drill bit with but a small loss of power and to drill into rock with a hammer drill almost as rapidly at the end of such composite drill rod of great length as with a short drill bit. As far as I am aware, this method of transferring the energy from the hammer to the drill bit has never been employed before, so that it has been impractical to drill long holes with the hammer drill. At the present time the drilling of long holes is accomplished by the use of the diamond drill and rotary drills, but the cost of such drilling is almost prohibitive in or- .dinary work as is evidenced by the slight use made of them. Y

IVhere the series of rods and drill are of equal length, as is set forth and claimed in Letters Patent No. 1,006,661, granted to me Oct. 24, 1911, there is practically no tendency of the rods and drill to separate when the percussive impulses are applied through the hammer, and hence the rapid vibrations will be transferred to the drill with little loss of energy; on the other hand, if there is inequality of length in the series of rods and bit these elements will separate and there is a severe loss of energy as the result.V In order to overcome this tendency to separation, an important feature of the present invention comprises means for exerting a constant pressure upon the rods to effectually hold them and the bit together during the application of the percussional blows by the hammer.

The length of the rods of the rod series is generally governed by the area of the confined underground space in which the drilling engine is operating, and the distance through which the engine may bermoved on its support. The length of the sections of tube surrounding the rods is also governed by the same conditions. In practice I have drilled into rock to distances up to one hundred feet using rods of lengths between two feet and three and one-half feet, depending on the conditions of operation.

The rods 8 are supported centrally and alined with the tube 7 by means of the longitudinal ribs 12 formed on the interior face of the tube. These ribs support the rods so that they are held in perfect alinement with each other and with the tappet and drill bit, but the contact between the rods and the ribs is such that the rods are free to move lengthwise. These ribs terminate in the tube above the drill bit 9, the shank 18 of which is made to lit the interior of the tube, so that the drill bit is held in a straight line.

As herein shown, (see Figs. 7 and 8), some of the rods 8 are of greater length than others so that the elements constituting the rods and bit series are of unequal length. By inequality of length in this connection I mean material inequality, and not such inequality as might be considered approximate equality.

The drill bit 9 is loosely and detachably connected to the lower section of the tube so that it is free to move longitudinally with respect thereto and may be detached therefrom when desired. This is accomplished by means of a modified bayonet joint 14. The inner end of the tube is provided with an open clutch l5 which opens onto the end of the tube through the slot 16, which is narrower than the cut away portion forming the clutch. The shank 13 is provided with an elongated lug or boss 17 which is adapted to enter through said slot 16 and engage the clutch.

It is essential that the drill bit be rotated during the operationof the drill so that the cutting edges of the drill bit come in contact with all parts of the rock face.

As the drill is operating the tube is rotated in such direction that the lug is moved in the cut away portion to one side of the slot 16, so that the movement of the drill bit is limited to the length of the cut away portion and under such circumstances cannot become detached from the tube. Should the drill bit become stuck in the drill hole so that it cannot be removed, the tube is rotated in the opposite direction, bringing the lug in line with the slot, so that the tube and rods can be withdrawn, allowing the drill bit to remain in the hole.

In order to overcome the friction between the rapidly moving drill bit and the side of the aperture as the tube is being rotated, the faces of the aperture and lug are inclined in such manner that in the forward movement of the drill bit, the lug springs away from the aperture face. This allows all of the energy imparted to the bit to be used in cutting the rock and obviates a loss of energy at that point. The pressure between the lug and the face of the aperture as the drill is being rotated in ordinary work is approximately 500 pounds and the energy lost in overcoming the friction due to such pres@ sure would be very large. By forming the side of the aperture at an angle, however, the lug moves out of contact with the face as it begins its forward fnovement and the friction is avoided.

The tube may be rotated by hand or aower, as desired. When it is to be rotated by hand, a handle 18 attached to the sleeve 29 is provided adjacent to the drilling machine. As the tube advances into the hole, the set screw 31 may be loosened and the sleeve 29 clamped on the next section 0f the lliquid at the face of the drill tube added. The tube may also be rotated by gripping it with a pipe wrench when a handle such as 18 is not convenient. I have also provided means for rotating the tube by power, preferably from the same source as that used to operate the hammer. This mechanism is inclosed in a casing 20 at the forward end of the machine and is supplied with power through the conductor 21. A valve 23 is employed for cutting off the power supply when desired. Within the casing is the reciprocatingl piston 24, which operates the bent lever 25 pivoted to the side of the casing at 20. Mounted on this lever 25 is a spring held pawl 27 which engages the ratchet 28. This ratchet is shown as formed integral with the sleeve or collar 29 through which the tube projects and to which it is clamped by the set screw 31. An oppositely placed spring held pawl 32 prevents a reverse rotation of the ratchet. lt is evident that as the piston 24 reciprocates, the pawl 27 acts to rotate the sleeve 29. The compressed-air for operating the piston enters the annular space 106 formed by the shoulder 112 on the piston through the passage 105, and moves the piston downward. At the end of the stroke, the port 109 registers with the chamber 106 and allows the air to move through the passage 108 into the chamber 107 which reverses the direction of motion of the piston. At the end of the upward stroke the passage 110 registers with the outlet port 111 and allows the air to exhaust. The valve 23 is then opened to allow air to again enter the chamber 106.

Provision is also made for introducing a bit. The upper end of the tube 7 is clamped in the chuck 6 which opens into the chamber 34. Water is supplied to this chamber through the inlet pipe 35 to which is attached the conductor 36. The water is forced into the chamber under the rquired pressure by means of the force pump 37 which may be operated by the compressed air supply. Provision is also made for introducing a quantity of air with the water by connecting the water sup ply conductor 36 with the air conductor by the conductor 38. A cock 39 is arranged at this point of connection to regulate the air supply to the pump 37 and the chamber The tube 7 is clamped in the chuck 6 by means of the clamping ring 41 and the set screw 42 and is held in such position that the end thereof is adjacent to the inner end of the chuck. A ledge 43 is provided on the inner surface of the chuck to seat the tube at the proper place. The last rod of the rod series lies in the tube and projects from the end thereof so that it is in position to be struck by the tappet 4 which also lies partly within the chamber 34. To prevent leakage from this chamber, the chuck and the tappet are surrounded with packing 45 which is held confined by the packing rings 46. These packing rings are held apart and pressed against the packing by the spiral spring 47 thereby providing a very eflicient water tight joint.

The water entering chamber 34 passes into the tube 7 between the tube and the rods and is conveyed to the forward end of the tube. To provide means for transferring the water from the outside of the rods to the inside of the drill bit, the first rod is provided at its forward end with an aperture 48 arranged centrally therein and opening on the side of the rod. The hollow portion is made of the same diameter as the drill shank, which is also made hollow for the purpose of conducting the liquid therethrough. The passage 49 in the drill shank terminates in a groove 51 in the side of the drill bit, and near the upper or rear end of the drill bit head. The groove 51 closed at the rear end extends for the length of the drill bit head and conveys the liquid to the cutting face. The liquid carrying the rock cuttings then Hows backward between the tube and the face of the drilled hole and may be collected and examined to determine the formation through which the drill bit is passing.

rlhe drill bit which I employ in connection with the rod series is of novel construction and is the only bit that l am aware of which will operate in conjunction with the apparatus of my invention to drill a long cylindrical straight hole of equal diameter at all depths. Heretofore, deep holes must necessarily have been drilled smaller at the bottom than at the top, due to the wear on the bit, 'but this objectionable feature has been eliminated by the use of the present bit. ln drilling holes with the present apparatus it is essential that the hole be straight and of substantially constant diameter in order to allow the tube surrounding the rods to enter the hole.

The drill bit is preferably formed with a prismatic head to which is welded the shank which engages the tube. The face of the bit is formed with an eccentric point 87, which is of substantially conical shape. The eccentric point cuts into the face of the rock and the edges 88--101-96 and 10i?J of the body cut into the sides and preserve the width of the hole. These edges are long and suffer very little wear, even on the side opposite the eccentric point, although thrown strongly against the side of the drill hole by the glancing blow of the point. A new drill of the same size inserted into the hole -when the one being used is worn, will always advance to the, end of the hole. The face of the eccentric cone shaped point 87 is provided with cutting edges 89--90- 91-92# 93-94--95 on that side which is farthest from the axis of the drill. The groove in the bit for allowing the water to flow to the drillface is arranged on that side of the drill bit head which is opposite the eccentric point, and which is held against the rock. On account of the eccentricity of the forward cutting edges, and the rotation of the drill, the bit glances on the rock face as it strikes, causing the side edges of the prism to strike against all sides of the drill hole. The sloping edges of the eccentric point do not cut the whole of the end of the drill hole, but leave a small concentric rock shelf which is cut down by the shovel edges 10G- 88, 88-S9, 98-96 and 96-97 on the side of the bit opposite the eccentric point. The effect of the cutting of the side of the drill hole by the long side edges of the prismatic head and of the cutting of the rock shelf by the shovel edges is that the drill hole is always from 9g to fig of an inch larger than the drill bit. The hole remains straight on account of the length of the side edges opposite the eccentric point, their parallelism with the drill axis, and the avoidance of all flare of these edges at their forward ends. This is a novel feature of this bit and practically essential in the drilling of straight holes through broken rock formations.

Provision has also been made for advancing the tube into the drill hole as the rock is cut away and for withdrawing theV tube when desired, the same devices that perform these functions also serving inthe embodiment of the invention herein illustrated, to hold the series of rods and bit together. Arranged below the hammer cylinder 2 and in close relation thereto is the pressure cylinder 52 in which operates the hollow piston 53. The piston 53 is connected to a rod 54, in this instance through the casing containing the power operated tube rotating mechanism. The rod 54 lies adjacent the hammer cylinder 2 and is provided with a series of lugs 55, between any two of which the lug 56 on the rotatable ring 57 on the hammer cylinder' is adapted to engage. The ring 57 is loosely mounted for rotation on the cylinder so that it can be turned to engage or disengage the lug 56 with the rod 54. It is evident that when in engagement a movement of the piston 53 causes a simultaneous movement of the cylinder 2 and the tube rotating mechanism, so that the tube is moved as desired. It will also be evident that the piston 53 will act through the rod 54 and cylinder 2 to hold the tappet 4 against the end rod or in such close proximity thereto that the several rods and bit cannot separate. This is a valuable characteristic of the present improvements, as it is essential that where the rods and bit, considered as a series, are not of equality of length some means be provided to hold them against separation. In this connection, the particular instrumentalities employed for such purpose are not essential to this invention, as other means, such as a weight, might be employed if desired.

The piston 53 is hollow and is provided with valve connections so that the power may be applied from one source to move the piston in either direction. Power is supplied in the form of compressed air through the conductor 21 which also carries the compressed air to the tube rotating means. A four way valve 58 arranged in a block Xed to piston 53 is arranged so that when the compressed air is admitted to one side of the piston head 59 the other side is in connection with the exhaust 6l. As shown in the drawings, the air passes down through the pipe 62 to behind the head 59 thereby moving the piston and tube forward. The air in the cylinder on the other side of the head is exhausting through the port 63, the hollow piston 53, the passage 64 and the eX- haust 6l. When the valve 58 is turned the air current travels in the opposite direction, moving the piston backward and withdrawing the tube. The valve is provided with a handle 65 on the outside of the piston adjacent the tube rotating means so that the longitudinal movement of the tube may be readily controlled.

I claim:

l. In a rock drilling apparatus having a drilling engine of the hammer type constructed to apply percussional impulses of high frequency and in combination with a hammer and drill bit, a series of separate alined contiguous rods intermediate said hammer and said drill bit, a tube surrounding said rods and engaging said drill bit and means for rotating said tube and drill bit without subjecting the rods to torsional strain.

2. In a rock drilling apparatus having a drilling engine of the hammer type constructed to apply percussional impulses of high frequency, and in combination with its hammer and drill bit, a series of separate, alined, contiguous rods intermediate said hammer and drill bit, a jointed pipe inclosing said rod series provided with means for detaching the pipe from the drill including an aperture in the pipe with an inclined face to engage a lug on the drill bit and means for revolving the pipe.

3. In a rock drilling apparatus having a drilling engine of the hammer type and in combination with its hammer and drill bit, a series of rods intermediate said hammer and drill bit, a tube surrounding said rods and the shank of the drill bit, said tube Ibeing provided near its end with an aperture, and a lug on the shank engaging said aperture, the aperture having a bearing surface adapted to bear against the lug when the drill is rotated in one direction, the side of the aperture being inclined to the aXis of the drill so that a forward movement of the drill bit causes the lug to move away from said bearing surface.

4. In a rock drilling apparatus, a drill bitv adapted to extend entirely into the drill hole, a tube surrounding the shank of said drill bit, means for imparting a blow to said drill bit, means for revolving the tube and means comprising interengaging parts connecting said tube and drill bit for revolving the drill bit, said parts having inclined faces operating to minimize the friction between said tube and shank on the forward motion of the drill bit.

5. In a rock drilling apparatus having a drilling engine of the hammer type constructed to apply percussional impulses of high frequency and in combination with its hammer and drill bit, a series of separate rods alined with and intermediate the hammer and drill bit, a tube surrounding said rods and the drill bit shank, said tube being unconnected to said rods, a connection between the tube and the shank to cause a rotation of the drill with the tube, a sleeve attached to the tube at its outer end and power operated means arranged to rotate said sleeve.

6. In a rock drilling apparatus having a drilling engine of the hammer type constructed to apply percussional impulses of high frequency and in combination with its hammer, a drill bit entirely entered into the drill hole, means for transmitting the blow of the hammer to said drill bit consisting of a series of separate rods alined with each other and intermediate said hammer and drill bit, means for continuously holding said rods and bit together, a tube surrounding said transmitting means and means for inroducing a fluid under pressure into said tu e.

7. In a rock drilling apparatus having a drilling engine of the hammer type constructed to apply percussional impulses of high frequency and in combination with its hammer, a drill bit entered entirely into the drill hole, a series of separate rods alined with and intermediate said hammer and drill bit arranged to transmit an energy wave continuously from the hammer to the drill bit, a tube surrounding said rods and the drill bit shank, said tube and drill bit being provided with a continuous passage, means for revolving the tube and drill bit and means for introducing a fluid under pressure into such continuous passage.

8. In a rock drilling apparatus having a drilling engine of the hammer type constructed to apply percussional impulses of high frequency and in combination with its hammer and drill bita series of separate rods alined with and intermediate said hammer and drill bit, means for pressing said rods together, means for continuously holding said rods and bit together, a tube surrounding said rods and the drill bit shank, the shank of the drill bit and the end of the rod adjacent thereto being of substantially the same diameter as the interior of said tube and being provided with alined passages arranged longitudinally therein and terminating at the side of the rod and in a groove on the side of the drill bit, and means for conveying a fluid through said tube and passages.

9. In a rock drilling apparatus having a drilling engine of the vibratory hammer type and in combination with the hammer, a drill bit adapted to be rotated, a tube surrounding the drill bit shank and detaehably connected thereto, a series of rods for transmitting the blow from the hammer to the drill bit arranged intermediate the hammer and drill bit, means for continuously holding the leading rod of the series and the drill bit together during the operation of the hammer, the leading end of the leading rod and the drill bit shank being provided with central alined passages, the rear end.

of the passage in the rod terminating eccentrically of the rod.

10. In a rock drilling apparatus the combination with a hammer constructed to apply percussional impulses of high frequency, a drill bit, a series of alined rods between said hammer and bit, said series of rods and bit being of unequal length, and means for holding the members of the series together.

11. In a rock drilling apparatus the combination with a hammer constructed to apply percussional impulses of high frequency, a drill bit, a series of alined rods between said hammer and bit, said series of rods and bit being of unequal length, and means for holding the members of the series together by pressure in the rear thereof.

12. In a rock drilling apparatus the combination with a hammer constructed to apply percussional impulses of high frequency, a drill bit, a series of alined rods between said hammer and bit, said series of rods and bit being of unequal length, and a power-actuated piston and connections to hold the members of the series together.

13. In a rock drilling apparatus the combination of a hammer drilling engine, a drill bit, a series of alined rods between said hammer and bit, a tube surrounding said rods and the shank of said drill bit, and power-actuated means under manual control for causing movement of said tube in opposite directions for withdrawing it from or inserting it in the drilled hole, said hammer drilling engine being adapted to be removed from the apparatus and said power-actuated means being adapted to move said tube while the drilling engine is removed.

14:. In a rock drilling apparatus, the combination of a hammer constructed to apply percussional impulses of high frequency, a drill bit, a separate rod between the hammer and bit of unequal length with the bit, and means for holding the rod pressed against the bit, said separate rod being several times as long as the hammer and at least twice as long as the drill bit and adapted to transmit by wave action the percussional impulses of the hammer blow, said bit and rod being adapted to be entirely entered into the drill hole.

15. In a rock drilling apparatus having a drilling engine of the hammer type constructed to apply percussional impulses of high frequency and in combination with its hammer, a drill bit entirely entered into the drill hole, means for transmitting the blow of the hammer to said drill bit, consisting of a series of separate rods alined with each other and intermediate the hammer and drill bit, said series of rods and bit being of unequal length and a tube surrounding said rod series, the tube and rods ,being arranged in such position that the blow of the hammer is delivered to the rods and not to the tube, and means for continuously holding said rods and bit together.

16. In a rock drilling apparatus having a drilling engine of the hammer type constructed to apply percussional impulses of high frequency and in combination with its hammer and drill bit, a series of separate alined rods arranged between the hammer and drill bit shank, a tube surrounding said rods and drill bit shank, means for advancing and retiring said tube and a detachable interlocking connection between the tube and the drill bit shank, said connection being such that the tube is capable of considerable longitudinal movement independent of the shank.

In testimony whereof I have hereunto set my hand at San Francisco, California, this 31st day of August, 1911.

MOSES ARTHUR KNAPP.

In presence of- H. G. PRosT, R. HEFFERNAN.

Copies of this patent may be obtained for ve cents each, by addressing the Commissioner of Patents;

Washington, D. (1.

Images