US1829245A - Blowing device for rock drills - Google Patents

Description

Oct. 27, 1931. w, s JR 1,829,245

BLOWING DEVICE FOR ROCK DRILLS Filed June 29, 1929 I N VEN TOR.

mmamlsmzmw BY X. H15 ATTORNEY Patented Oct. 27, 1931 UNITED TATE ZS l r tTET OFFICE WILLIAM .A. SMITH, JIL, F PEILLIPSBURG, NEW JERSEY, ASSIGNOB TO INGERSOLL- RAND COMPANY, OF JERSEY CITY, NEW JERSEY,

A CORPORATION OF NEW JERSEY BLOWING DEVICE FOR EOCK DRILLS Application filed June 29,

This invention relates to rock drills, but more particularly to a blowing device for rock drills of the fluid actuated type.

One object of the invention is to assure a thorough cleansing of the drill hole.

Another object is to eliminate the necessity of manipulating a plurality of devices to bring about this result.

Other objects will be in part obvious and in part pointed out hereinafter.

In the drawings illustrating one form which the invention may assume in practice and in which similar reference characters refer to similar parts,

Figure 1 is a. sectional elevation of a rock drill having the invention applied thereto, and

Figure 2 is a transverse view taken through Figure l on the line 2-2 looking in the direction indicated by the arrows.

Referring to the drawings, A. designates a rock drill comprising a cylinder B having a piston chamber C in which is disposed a reciprocatory hammer piston D. The piston chamber C is provided with an exhaust port E which is normally controlled by the piston D and is closed at its front end by a front cylinder washer F which also serves to centralize the cylinder B with respect to a front head Gr disposed at the front end of the cylinder B.

The piston D is illustrated as having a forward reduced extension H which extends slidably through the front cylinder washer F and is' provided with a plurality of longitudinally extending flutes J adapted to interlockingly engage ribs K carried in this instance by a chuck L which is adapted to rotate in the front head G and serves as a guide for a hollow working implement 0 against which the piston D delivers its blows.

In the rearward end ofthe cylinder B is an enlarged bore P adapted to receive rota.- tion mechanism Q, and valve mechanism des signated by R. The rotation mechanism may comprise the usual ratchet ring S having introverted teeth T which serve as abutments for spring pressed pawls U carried by the head V of a rifle bar TV. The head V of the rifle bar lies within the ratchet ring S and 1929. Serial No. 374,763.

in the rifle bar W are formed flutes X which may interlock with the piston D in a well known manner to transmit the rotary movement of the rifle bar to the piston and thus to the chuck L for rotating the working implement 0.

Disposed at the rearward end of the cylinder B and in this instance seated on the ratchet ring S is a back head Y which may be clamped in operative position in any suitable manner and has a throttle valve chamber Z in which is disposed a throttle valve 6 for controlling the admission of pressure fluid into the drill A. The throttle valve Z) is illustrated as being of the rotary type and is accordingly provided with a lever c whereoy it may be rotated from one position to another.

Formed coaxially in the throttle valve 6 is a bore d which may be in constant com munication with a source of pressure fluid supply through a hose or other suitable connection (not shown).

a The valve mechanism R comprises a Valve chest 6 consisting in this instance of a pair of plates 7" and g. The plate f serves both as a closure for the rearward end of the piston chamber G and also as a seat for the plate 9 and the plate 9 in turn acts as a seat for the 1Batchet ring S and for the head V of the rifle The plate 9 is suitably recessed to form a distributing valve chamber 7i wherein is disposed a distributing valve 7' of the plate type having opposed wings 7c and 0 which taper outwardly from a central fulcrum p whereon said valve is adapted to rock.

From the valve chamber h leads a front inlet passage which opens at its forward end into the front end of the piston chamber G and a rear inlet passage 9 also leading from the valve chamber it opens into the rearward end of the piston chamber C.

The pressure fluid intended to be distributed by the distributing valve j flows to the valve chamber in through supply passages r in the ratchet ring S and the plate 9 and which passages lead from the supply reservoir s in the back head Y, and the pressure fluid is conveyed to the supply reservoir s by a passage t in the back head Y wherewith a port the throttle valve is adapted to register.

' In the present instance the drill A is provided with a water'tube o whichleads from the back head coaxially through the drill and extends with'its forward end into the rearward end of the working implement 0 so that water may be constantly introduced into the drill steel and thus through the drill steel into the drill hole. During the normal operation ofthedrill the pressure of the water will be augmented to some extent bv pressure fluid flowing from the forward end of the piston chamber C through the flutesJ into the drill steel.

f Under most drilling conditions the means described will assure a fairly clean rock face. There are, times however, when the cuttings accumulate to such an extent in the drill hole that their removal can only be effected by introducing large quantities of pressure fluid into the drill hole'to cleanse the working surface. In furtherance of this end the rock drill A is provided; with a blower valve chest 10 comprising in this instance a cover 00 and a plate g interposed between the cover 00 and .the cylinder B. The partscomprising the valy e chest may be secured to the cylinder in any-suitable and convenient manner as for stance bymeans'of bolts 2 upon which are threaded nuts 2. p I r ;..The,plate 11 is recessed to forma blower valve chamber 3 forthereception of a blower valve 4 in the formof a flat plate adapted L to reciprocate in the chamber E and having a port 5'therethrough which,in the open position ofthe blowervalve, registers with the exhaust port E. I p

In order to normally hold the blowervalve 4 in the open position sothat pressure fluid may exhaust through the exhaust port E to the atmosphere a spring 6 is disposed inthe I valve chamber 3 to bear against one end of the valve land with its other end against the platey. A vent 7 may be formed in theplate y adjacent the spring 6 to prevent the accumulation of pressure in that end of the valve chamber 3.

The valve4 is adapted to be actuated into the closed position by pressure fluid which may be conveyed into the rearward end of thevalvezchamber through a supply passage 8 leading from the'throttle valve chamber Z and to which passage pressure fluid may be supplied from the interior of the throttle valve 12 by a port 9 in the valve. The passage 8 also serves to convey pressure fluid from the valve chamber 3 and in order to exhaust the pressure fluid from the valve chamber 3, the throttle valve is provided with an external groove 10 which, in one position of the throttle valve, registers with the supply passage 8 and with an exhaust port 11 leading fromuthethrottle valve chamber Z to the 7 atmosphere.

In the construction shown the pressure fluid supplied to the front end of the piston chamber for the purpose of blowing the dirt to the drill hole passes through the distributing valve chamber 72, and must therefore pass over a raised end of the valve-j. It istherefore essentialthat the said valve j be prevented from tilting during the blowing op eration. In order to assure this result a cavity 12 is formed in the plate 9 beneath the wing 76 and a conduit 13le ads from-the cavity 12 to the throttle valve chamber Z where it may register with an external groove 14 in the throttle valve 7) which affords communication between the conduit 13 and an exhaust port 15 leading to the atmosphere. The end of'the conduit 13 preferably opens into the throttle valve chamber Z at a point where the port 9 in the throttle valve 6 may register therewith for admitting pressure fluid directly from the throttle. valve into the cavity 12 whenever it is desired to resume drilling. By; thus admitting pressure fluid into the cavity 12, the tendency of the valve 7' to adhere to its seat will be entirely eliminated.

, The operation of the device is as follows: Normally during drilling the throttle valve 6 will occupy a position in which pressure fluid flowsthrough the port a into the passage a" thence through the supply reservoir 3 and the-supply passage 1' into the valve chamber 71. Assuming. then the piston D to be in the rearward position illustrated in Figure 1 pressure fluid will flow over the wing is of of the piston chamber will be compressed and such compression will flow through the inlet passage if to act against the wing 0 of the valve. t about the t1me the piston delivers its blow against the working implement the compression in the front end of thepiston chamber will have, attained its, maximum value and the valve will then be tipped to its other limiting position. The force of the compression-however will be augmented to a considerable extent by'thesuction created by'the pressure fluid flowing. over the raised wing 70. This movement'of the valve however will not occur until thepiston D has un covered the exhaust port E to permit the pressure fluid to exhaust from the rearward end of the piston chamber to the atmosphere.

Upon reversal of the valve in the manner described thepressure fluid will flow over the wing 0' through the inlet passage 29" into the front end of'the piston chamber to drive the pistonD rearwardly. As during the forward stroke, compression will be built/up in the rearward end of the piston chamber during the rearward strok of- .thepiston and i law such compression acting against the wing is, together with the pressure fluid flowing over the raised wing 0, will restore the valve to its initial position.

During the normal operation of the drill, the port 9 in the throttle valve 6 will be in registry with the conduit 13 and pressure fluid will therefore be admitted into the cavity 12 to accelerate .the action of the valve y. In the same position of the throttle valve Z) the groove 10 will aflord communication between the supply passage 8 and the exhaust port 11 so that the rearward end of the valve chamber 3 will be vented to the atmosphere and the valve 4': will be held in the open position by the spring 6. The port 5 in the valve t will then be in registry with the exhaust port E.

When the drill is being thus operated, a

portion of pressure fluid will flow from the front end of the piston chamber C during each rearward stroke of the piston D. The course of such pressure fluid will be through the flutes J in the extension H of the piston and through the chuck L and the hollow working implement 0 into the drill hole. Obviously only a small amount of pressure fluid may be thus introduced into the drill hole. Under some conditions as for instance when drilling shallow holes, the amount thus supplied to the drill hole may be adequate to maintain a clean rock surface. In drilling deep holes however, or when drilling certain rock formations it is practically impossible to maintain a clean working surface by intermittently introducing pufls of pressure fluid into the drill hole and the cuttings will therefore accumulate in the drill hole to such an extent that they interfere greatly with the rotary movement of the working implement.

hen this condition occurs the throttle valve 7) may be rotated to the position illustrated in Figure 1 in which the port 9 in the throttle valve will register with the supply passage 8 and pressure fluid will then be admitted into the rearward end of the valve chamber 3 to actuate the valve 4 into a posi tion in which it will cover the exhaust port E. At the same time the port a in the throttle valve will remain in registry with the passage t so that a full supply of pressure fluid will be delivered to the valve chamber it.

By rotating the throttle valve to the posltion for introducing pressure fluid into the valve chamber 8, the groove ll in the throttle valve will be carried into a position to estab lish communication between the conduit 13 and the exhaust port 15 so that the cavity 12 will be opened directly to the amosphere. In this way the wing is of the valve j will remain firmly seated and the pressure fluid will flow over the raised wing 0 through the inlet f passage p into the front end of the piston chamber C.

Upon entering the front end of the piston chamber, the pressure fluid will drive the pisconveying pressure fluid I chamber, a distributing valve for the piston ton D rearwardly so that the rearward end of the flutes J will be drawn into the piston chamber and a large supply of pressure fluid will then flow through the flutes J and through the chuck L and the working implement into the drill hole. The parts may occupy these positions until the hole has been thoroughly cleansed, whereupon the throttle valve may be rotated to the position previously described in which the rearward end of the valve chamber 3 will again be vented to the atmosphereand pressure fluid will be supplied to the cavity 12 to permit normal operation of the drill. The spring 6 will then open the blower valve 4 and the piston chamber will be opened directly to the atmosphere through the exhaust port E.

v I claim:

1. In a blowing device for rock drills, the combination of a cylinder having a piston chamber and a hammer piston in the piston chamber, an exhaust port for the piston chamber, a pressure actuated valve for con-' trolling the exhaust port, a distributing value for the piston chamber, and means including passages and a throttle valve therefor to simultaneously vent one side of the distributing valve to atmosphere and close the pressure actuated valve.

2. In a blowing device for rock drills, the combination of a cylinder having a piston chamber and a hammer piston in the piston chamber, said piston having a passage for from the piston chamber, a valve chamber in communication with the exhaust port, a pressure actuated valve in the valve chamber to control the exhaust port, means including supply passages for directing pressure fluid to the distributing valve and the piston chamber, a separate passage for directing pressure fluid through the cylinder to the valve chamber, to close the pressure actuated valve and to supply pressure fluid to the passage in the piston, and a conduit for opening one side of the distributing valve to atmosphere while the pressure actuated valve is closed.

3. In a blowing device for rock drills, the combination of a cylinder having a piston chamber and a hammer piston in the piston chamber, said piston having a passage for conveying pressure fluid from the front end of the piston chamber, a distributing valve for the piston chamber, an exhaust port normally controlled by the piston, a valve chamber communicating with the exhaust port, a pressure actuated valve in the valve chamher to form a closure for the exhaust port, supply passages for conveying pressure fluid rom a source of supply to the valve chamber and to the front end of the-piston chamber for supplying pressure fluid to the passage in the piston and for actuating the pressure actuated valve to a position for closing the 1 exhaust. port thus closing communication between: the piston chamber and the atmosphere, a: conduit foropening one side'ot the distributingivalve to atmosphere while the pressure actuated valve is closed, and a throttle valve to control the supply passages andthe conduit 1 I I r 4. In a blowing device for rock'drills, the combination of a cylinder having a piston chamber, and a hammer piston in the piston chamber, an exhaust port for the piston chamber, a blower valve chamber communleating with the exhaust port, a blower valve 1n the valve chamber to form a closure for the exhaust port and thus closing communication between bothends of the piston chamber and the atmosphere, a .distribut-' ing valve chamber for the cylinder having a distributing valve-therein, rear and front inlet passages leading from the distributing valve chamber to the piston chamber, a throtl tle' valve chambergsupply'passages'leading from'the throttle valve chamber to the distributing valve c-hamber,;a supply passage leading fromthe throttle valve chamber for conveying pressure fluid to "and .from the blower valve chamber, a COIlClUltlfldlIlg from one side of the distributing'valve chamber to the throttle valve chamber, and a throttle} valve in :the throttle valve chamber to control the supply passages and the conduit and hav ing ports and passages for opening the conduit'tothe atmosphere for'ventingooneside of thedistributing valve chamberand for simulspecification,

I taneouslyfad-mitting pressure, into tlieifront 'end of thepiston chamber and into the blower valve-chamber to retract the piston and'to close the blower valve. 7 V *In testimony whereof I have signed this WILLIAM ALL-SMITH, 1;

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