US2081920A - Rock drill - Google Patents

Description

E. G. GARTIN `une l, 1937.

Roux DRILL Filed Aug. 17, 1934 2 Sheets-Sheet l Jlm l, 1937. E, G, GART|N f 2,081,920

ROCK DRILL Filed Aug. 1'?, 1934 2 Sheets-Sheet 2 Ef/mer @anim y AM A www Patented June 1, 1937 PATENT @FFICE 2,081,920 ROCK DRILL Elmer G. Gartin, Claremont, N.

Sullivan Machinery Company,

Massachusetts H., assigner t a corporation of Application August 17, 1934, Serial No. 740,298

10 Claims.

This invention relates to rock drills, and more particularly has reference to improvements in the drill steel actuating and rotation means for a rock drill of the pressure fluid actuated hammer type.

An object of this invention is to provide an improved rock drill. Another object is tov provide an improved pressure fluid actuated hammer motor for a rock drill, having improved fluid distribution means. A further object is to provide an improved rotation mechanism.v for the drill steel of a rockdrill, the rotation mechanism having means associated therewith controlled by the valve mechanism of the fluid distribution means. Yet another object is to provide an improved drill steel rotation mechanism wherein rotative movement is effected by means of a riile bar and having improved means for controlling rifle bare rotation, said control means being associated with and controlled by the valve mechanism of the fluid distribution means. These and other objects and advantages of the invention will, however, hereinafter more fully appear.

In the accompanying drawings there are shown for purposes of illustration one form and a modication thereof which the invention may assume in practice.

In these drawings,-

Fig. 1 is a longitudinally extending, vertical sectional view taken through the villustrative form of the improved rock drill.

Fig. 2 is an enlarged, fragmentary sectional view taken in the planes of Fig. 1, showing details of construction of the improved fluid distribution and rotation means.

Fig. 3 is a view similar to Fig. 2 showing the motor parts in a different position.

Fig. 4 is a cross sectional view on an enlarged scale taken substantially on line 4--4 of Fig. 1.

Fig. 5 is a fragmentary plan View of the fluid supply connection shown in Fig. 4.

Fig. 6 is a rear end elevational View of the front valve chest plate.

Fig. 'I is an end elevational view of the improved iluid distributing valve.

Fig. 8 is an end elevational view of the valve guide bushing.

Fig. 9 is a perspective view showing the improved rotation bar.

Fig. 10 is a perspective view showing the rotation bar control friction.

Fig. 11 is a iront end elevational view of the rear valve chest plate.

Fig. 12 is a detail sectional view taken in the plane of Fig. 1 showing a modified form of fluid supply connection.

In the illustrative embodiment of the invention there is shown a rock drill of the pressure, fluid actuated hammer type comprising a cyline' der I having a bore 2 containing a reciprocatory hammer piston 3. The hammer piston has a forwardly projecting striking bar 4 having a sliding fit in a bushing 5 mounted within a front". buffer ring 5, and this striking bar is adapted to` deliver impact blows to the shank 'I of a usual lugged drill steel 8. The drill steel shank is mounted in a chuck bushing 9 supported within a .chuck sleeve I0 rotatably mounted in a frontN chuck housing II suitably attached toi the for? ward end of the cylinder. The motor cylinder is provided with a rear head plate I3 arranged in a bore I4 alined with the cylinder bore; and also arranged in the bore I4 and abutting the rear surface of the plate I3 is a valve chest plate I5,"'

while interposed between the plate I5 and a rear head block I6 and also arranged in the bore I4 is an annulus I'I. The plates I3 and I5 and the annulus I'I are maintained in position within the bore I4 by the head block and the latter is attached to the rear end of the cylinder in any suitable manner.

Now referring to the improved fluid distribution means, it will be noted that swivelly mounted on a vertical axis on the rear head block I6 is a Figs. 4 and 5. Secured to the swivel valve casing I9 is a hose connection 26 leading toany suitable pressure iiuid source and communicable through a passage 21 in the valve casing and port 23 in the valve with the hollow interior 29 of the valve, Communicable with the hollow interior of the throttle valve is a passage 30 leading to an annular groove or recess 3| formed in the rear face of the annulus I'I. The plates I3 and I5 cooperate to form a valve chest and are suitably bored or recessed to provide a valve chamber 33 in which is reciprocably mounted a fluid distributing valve 34, herein of the sleeve type, having a sleeve-like body 35 and a central external flange 36. The distributing valve is slidably guided on a bushing or sleeve 31 seated at its ends within bores formed in the cooperating plates I3 and I5. Surrounding the valve chamber 33 is an annular groove or recess 39 formed in the forward face of the valve chest plate I5 and communicable through a series of passages 4U with the recess 3|. A front end elevational view of the valve chest plate I5 is shown in Fig. 11, and this plate is traversed by passages 4I, 4I, these passages connecting the valve chamber through passages 42 with the forward end of the cylinder bore. The front valve chest plate .I3 is traversed by passages 43, 43 for connecting the valve chamber directly with the rear end of the cylinder bore. The front face of the plate I5 is arcuately grooved at 44, 44 on an arc struck from the plate center and these grooves are constantly communicative through restricted passages 45, 45, herein in the form of narrow grooves cut in the forward face of the plate l5, with the fluid supply groove 39, while the rear face of the plate I3 is similarly arcuately grooved at 46, 4S, and these latter grooves are constantly communicable, through restricted passages 4l, 4l' herein in the form of narrow grooves cut in the rear face of the plate I3, with the fluid supply groove 3i?. The cylinder is provided with a centrally located piston controlled, free exhaust port 43.

The operation of the pressure fluid motor will be clearly apparent from the description given. When the parts are in the position in Fig. 2, pressure fluid flows from the throttle valve through passage 35, groove 3l, passages 40, fluid supply groove 3S through the valve chamber past the forward surface of the valve flange 36 and through the passages 43 to the rear end of the cylinder bore, the pressure fluid acting on the rear pressure area of the hammer piston to drive the latter forwardly to effect its working stroke, that is, to deliver an impact blow to the shank l of the drill steel 3. At this time the forward end of the cylinder bore is connected to exhaust through exhaust port 46, and as the piston head overruns the passage 48 the communication of the front end of the cylinder with the atmosphere is cut off, and, upon continued movement of the hammer piston, the rear edge of the piston head overruns the exhaust port 48 to connect the rear end of the cylinder bore to exhaust. As a result, there is a sudden drop in pressure within the rear end of the cylinder bore and in passages 43, and the constant pressure in the grooves 43, 43 acting on the rear pres sure area of the valve flange 35, together with the pressure in passages 42 and 4I compressed by the hammer piston, overcomes the opposing pressure in the grooves 44, 44, and as a result the valve is thrown from the position shown in Fig. 2 to the position shown in Fig. 3. When the parts are in the position shown in Fig. 3, pressure fluid flows through passage 36, groove 3l, passages 4B, groove 39, through the valve chamber past the rear surface of the valve flange 33 through passages 4I and 42 to the forward end of the cylinder bore, the pressure fluid acting on the front pressure area of the hammer piston to drive the latter rearwardly to effect its retractive stroke. At this time the rear end of the cylinder bore is connected to exhaust through the exhaust port 48, and as the hammer piston moves rearwardly the piston head overruns the exhaust port 48, thereby cutting off communication of the rear end of the cylinder bore with the exhaust. Upon continued rearward movement of the hammer piston, the forward edge of the piston head overruns the exhaust port 48, connecting the forward end of the cylinder bore to atmosphere, and, upon continued rearward movement of the piston, the pressure fluid trapped within the rear end of the cylinder bore is compressed. This compression pressure in the passages 43, 43, together with the constant pressure in grooves 46, 46 acting on the forward pressure area of the valve flange 33, overcomes the opposing pressure in grooves 44, thereby throwing the valve rearwardly from the position shown in Fig. 3 to the position shown in Fig. 2. These operations are Vrapidly repeated during normal operation of the motor.

Now referring to the improved rotation mechanism for the drill steel 3, and particularly to the improved means controlled by the fluid distributing Valve for controlling the rotation means, it will be noted that the annulus I 'I has formed therein a conical bore 50 having rearwardly converging walls, and arranged Within this bore is a conical member5I in the form of a cone clutch .element having mounted in a peripheral groove 52 thereon suitable friction material 53 for engaging the walls of the bore 55 to hold the member 5I against rotation. The member 5I has formed internally therein splined elements 54 interlocked with splined elements 55 formed externally on a rotation bar 56. This rotation bar is journaled at 5l' within the rear head block I E and extends axially forwardly through bores 58 and 59 formed in the Valve chest plates I5 and I3, respectively, and through the valve guide bushing 3l, and has formed on its exterior periphery spiral flutes 351 inter-locked with spiral vanes 6I formed on a rie nut 32 secured, as by threads 53, within the hammer piston 3. The passages 4I, 4I controlled by the fluid distributing valve lead directly from the valve chamber at the rear side of the valve to the forward end of the bore 5I! at the forward side of the cone clutch member 5I, and when the uid distributing valve is in the position shown in Fig. 2, the forward pressure area of the cone clutch member 5I is connected at atmosphere through passages 4I, 42 and the exhaust port 48. When the fluid ydistributing valve is in the position shown in Fig. 3, pressure fluid iiows from the fluid supply groove 39 to the valve chamber past the rear surface of the central valve ange and through passages 4I to the bore 55 at the forward side of the cone clutch member 5I, the pressure fluid acting on the forward pressure area of this cone clutch member to drive the latter rearwardly into tight frictional engagement with the walls of the bore 50, and due to the interlocking connection between the member 5I and the rotation bar 56, the 1 latter is held against rotational movement at that time. Thus, during rearward movement of the hammer piston, the latter is rotated because of its splined connection with the rifle bar, and this rotative movement of the hammer piston is transmitted to the drill steel through longitudinal grooves 65 formed on the piston striking bar and interlocked with straight vanes 66 formed on the chuck sleeve Il). This chuck sleeve is connected, through a clutch element 5l, to a driver element 68 rotatably mounted within the chuck housing and having drive lugs engageable with the lugs 69 of the drill steel so that when the chuck sleeve is rotated, the driver element 53 and the drill steel 8 are rotated therewith. It will thus be seen that the rotation mechanism is controlled entirely by the fluid distributing means of the pressure uid motor and that the rotation is entirely interrupted during the forward working stroke of the hammer piston and is automatically operated vupon the rearward stroke ofthe hammer piston. As a result the drill steel is intermittently rotated by the hammer piston as it is percussively actuated thereby.

In Fig. 12 there is shown a modified form of fluid supply connection comprising a stud 1!) threaded at 1I within the rear head block and having threaded thereon at its upper end a nut 12. Swiveled on the stud 10 is a valve casing 13 having on its bottom surface a chamfered flange 14 rotatably mounted in a recess 15 surrounding the stud. Formed in the valve casing 13 is a conical bore 16 having rotatably mounted therein a conical throttle valve 11 for controlling the flow of pressure fluid from a supply connection 18 through a passage 19 in the valve casing and a communicating passage 80 in the stud through the passage 3l) of the fluid distributing means. When the nut 12 is loosened the valve casing may be swiveled into any desired position relative to the stud and thereafter held in such position by tightening of the nut 12.

As a result of this invention, it will be noted that an improved rock drill is provided having improved drill steel actuating and rotation mechanism whereby the drill steel is actuated and rotated in an improved manner. It will further be noted that an improved pressure fluid motor is provided having associated therewith improved drill steel rotation means, the rotation means being controlled by the fluid distributing valve of the fluid distributing means, thereby improving the manner of rotating the drill steel while at the same time the rotation parts are comparatively simplied. These and other uses and advantages of the invention will be clearly apparent to those skilled in the art.

While there are in this application specifically described one form and a modification which the invention may assume in practice, it will be understood that this form and the modication thereof are 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:

l. In a rock drill, a cylinder, a piston reciprocable therein, a drill steel actuated by said piston, fluid distribution means for supplying pressure fluid to said cylinder to effect reciprocation of said piston, and drill steel rotation mechanism controlled by said distribution means for effecting steel rotation including a rotation bar interlocked with said piston and having splines and a rotation control clutch including an element having splines interlocked with the splines of said rotation bar, said element slidable relative to said bar, and means controlled by said distribution means for eiecting application and release of said clutch.

2. In a rock drill, a cylinder, a piston reciprocable therein, a drill steel actuated by said piston, fluid distribution means for effecting reciprocation of said piston, and drill steel rotation mechanism controlled by said distribution means and operated by said piston for effecting intermittent rotation of the drill steel including a rotation bar connected to said piston, a clutch element connected to said rotation bar for rotation therewith and movable axially with respect thereto, and a stationary clutch element with which said movable clutch element is engageable.

3. In a rock drill, a cylinder, a piston reciprocable therein, a' drill steel actuated by said piston, iiuid distribution means for effecting reciprocation of said piston including an automatic fluid actuated fluid distributing valve, and drill steel rotation mechanism controlled by said distributing valve and operated by said piston v.

for effecting intermittent rotation of the drill steel including an angularly movable rotation bar connected to said piston, a clutch element connected to said rotation bar for angular movement therewith and movable axially with respect thereto, and a stationary clutch element with which said movable clutch element is engageable.

4. In a rock drill, a cylinder, a piston reciprocable therein, a drill steel actuated by said piston, fluid distribution means for effecting reciprocation of said piston, and drill steelrotation mechanism controlled by said fluid distribution means and operated by said piston for effecting intermittent rotation of the drill steel including an angularly movable rotation bar connected to said piston, a clutch element splined to said rotation bar and movable axially with respect thereto, said clutch element angularly movable through its splined connection with said rotation bar, and a stationary clutch element coaxial with said movable clutch element and with which the latter is engageable.

5. In a rock drill, a cylinder, a piston reciprocable therein, a drill steel actuated by said piston, fluid distribution means for effecting reciprocation of said piston, and drill lsteel rotation mechanism controlled by said fluid distribution means and operated by said piston for eiecting intermittent rotation of the drill steel including a rotation Vbar slidingly interlocked with said piston, a stationary clutch element, and a reciprocable clutch element coaxial with and connected to said rotation bar for angular movement therewith, said reciprocable clutch element movable axially relative to said rotation bar in a direction rearwardly of the cylinder into engagement with said stationary clutch element to effect clutching of the rotation bar in a stationary position and movable forwardly toward ihe cylinder to effect free release of the rotation 6. In a rock drill, a cylinder, a piston reciprocable therein, a drill steel actuated by said piston, uid distribution means for effecting reciprocation of said piston including a valve chest coaxial with the motor cylinder at the rear end of the latter and having a valve chamber, an automatic fluid actuated iiuid distributing valve reciprocable in said valve chamber, passage means controlled by the valve and leading from the front end of the valve chamber to the rear end of the cylinder and passage means controlled by said valve and leading from the rear end of the valve chamber to the front end of the cylinder, and drill steel rotation mechanism controlled by said distributing valve and operated by said piston for effecting intermittent rotation of the drill steel including a rotation bar connected to said piston, and a iiuid actuated clutch for intermittently holding said rotation bar stationary, including a clutch member guided for reciprocation relative to said rotation bar and a stationary clutch member with which said reciprocable clutch member is engageable, and passage means within which flow is controlled by said valve and communicating with said second mentioned passage means for conducting actuating iiuid to said clutch.

7. In a rock drill, a drill steel rotation mechanism comprising an angularly movable rifle bar, a clutch for intermittently holding said rifle bar against angular movement including a reciprocable clutch member coaxial With said rifle bar and connected to said rie bar for angular movement therewith, said reciprocable clutch member guided for axial reciprocation relative to said rifle bar, a stationary clutch member with which said reciprocable clutch member is engageable, said reciprocable clutch member having a pressure area, and means for intermittently subjecting said pressure area to pressure iiuid to actuate said reciprocable clutch member into engagement With said stationary clutch member.

8. In a rock drill, a cylinder, a piston reciprocable therein, a drill steel actuated by said piston, fluid distribution means for effecting reciprocation of said piston including an automatic uid actuated fluid distributing valve for controlling the supply of pressure iiuid to the ends of said cylinder, and drill steel rotation mechanism operated by said piston for effecting intermittent rotation of said drill steel including a rotation bar connected to the piston and a uid actuated clutch for intermittently holding said rotation bar against rotation including a reciprocable clutch element connected to the rotation bar and guided for reciprocation relative thereto and a stationary clutch element with which said reciprocable clutch element is engageable.

9. In a rock drill, a cylinder, a piston reciprooable therein, a drill steel actuated by said piston, fluid distribution means for effecting reciprocation of said piston including an automatic i'iuid distributing valve for controlling the supply of pressure fluid to the opposite ends of said cylinder, and drill steel rotation mechanism associated with said iiuid distribution means and operated by said piston for eieoting intermittent rotation of the drill steel including a rotation bar connected to said piston, a clutch elementi connected to said rotation bar and guided for reciprocation, and a stationary clutch element with which said reciprocable clutch element is engageable, and means controlled by said distrbuting valve for actuating said reciprocable clutch element, said distributing valve when in a position to effect forward piston movement eiTecting automatic release of said reciprocable clutch element from said stationary clutch element and When in a position to eiect rearward piston movement effecting automatic engagement of said reciprocable clutch element With said stationary clutch element.

10. In a rock drill, a drill steel rotation mechanism comprising an angularly movable rie bar, a reciprocable actuator slidingly interlocked with said rifle bar, said rifle bar when held against angular movement eiecting partial rotation of the actuator upon relative sliding movement between said bar and actuator, a clutch for intermittently holding said rifle bar against angular movement including a reciprocable clutch member connected to said rifle bar and movable axially relative thereto, a stationary clutch member with which said reciprocable clutch member is engageable, said reciprocable clutch member hav- .ing a pressure area, and means for intermittently subjecting said pressure area to pressure fluid to actuate said reciprocable clutch member relative to said stationary member.

ELMER G. GARTIN.

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