US1792881A - Blowing device - Google Patents

Description

Feb. 17, 1931. P. A. WILLIAMS BLOWING DEVICE Filed Aug. 14. 1929 INVIENIOR. 11W hams Pei F QZK.

ATTORNEY Patented Feb. '17. 1931 sTAras "ATE OFFICE;

rn'rnn A. wI LIAMs, or WHITE trains, newyenn, .assrenon ro rrrennsonn-nann COMPANY, or JERSEY crrv, nnwaansnr, a conrene'rron or new JEnsnY BLOWING m1 zen Application filed August 14, 1929. Serial-No 385,886.

This invention relates to rock drills, but

more particularly to a blowing device for fluid actuated rock drills of the hammer type.

One object of the invention is to assurean abundant supply of pressure fluid to the drill hole for removing the cuttings therefrom. Y

Anotherobject is to assure a sealee. con: nection between thehollow working implement' and the source of pressure fluid supply during the blowing period, thus avoiding leakage of pressure fluid through the forward extremity of the rock drill.

Still another object is to avoid contact between the conduitthrough. which pressure fluid is supplied and theworking imple- Qment during the normal operation of the drill.

Other objects will be in part obvious an in part pointed out hereinafter. j

The figure in the drawing is a sectional elevation of a rock'drill equipped with a blowing device constructed in accordance with the practice of the invention.

Referring more'particularly to the drawing, A designates generally a rock drill comprising a cylinder B provided with a piston chamber 0 and having free exhaust ports'D V sagese and f and which also acts'as a closure to afford communication between the piston chamber and the atmosphere.

Disposed in the piston chamber C is a reciprocatory hammer piston E having a forward extension F which extends slidably through a front cylinder washer G at the front end of the cylinder B and is provided with longitudinal flutes H for engagement with ribs J carried by a chuck K. The chuck K may, as illustrated, abut with its rearward end the forward end of the front cylinder washer G and is disposed rotatably within a front head L preferably centralized with respect to the cylinder B by the front cylinder washer G. v

The chuck K may be of a well known'type having a bore 0 to receive and guide a working implement, such as a drill steel, only the I rearward end or shank P of which is shown. The working implement P has the usual bore Q, to convey cleansing fluid to the bottom of the hole being drilled. f

In the rearward end of the cylinder B is an enlarged bore R for the accommodation of rotation mechanism comprising a ratchet ring S and the head T of the rifle bar having flutes V for interlockingly engaging ribs W of, a rifle nut X threaded in the rearward end of thepiston E. The head T of the rifle bar may carry the usual spring pressed pawls (not shown) adapted for engagement with introverted teeth-Y carried by. the-rotation ring S for imparting rotary movement to the piston and thus also to the working implement P through the medium of the chuck K. r p

In the rearward and'forward ends of the 7 rotation ring S are formed annular chambers Z and b respectively, connected in this in"- stance by supply passages 0, also in the ro- "tation ratch S. The annular chamber Z serves as a supply reservoir, and the chamber 6 as a' valve chamber. to accommodate an annular plate type distributing valve d adaptedto control inlet passages e and/f leadingfrom the chamber 7) to the rearward and forward ends respectively of the piston chamber C. Aclosure is provided forthe front end of the chamber 6 bya back cylinderwasher g wherein are formed "the pas- 7 cylinder B in any suitablemanner. By seating the back head on the rotation ratchet S,

said back head for-ms a closure for the rearward end of the supply reservoir Z and in this instance also acts as a housing for a throttle valve 7' having a central chamber 70 into which pressure fluid maybe constantly admitted from a source of supply (not shown) and in the side of the throttle valve is aport 0 adapted to register witha passage 79 in the, back head and leading to the supply reservoir Z. r

During the operationof the parts so far described, the pressure fluid flowing from. the

" throttle'valveto the chamber 71 will be dis-' tributed to the ends of the piston "chamber by,

the valve d. The pressure fluid admitted through the inlet passage 6 into the rearward end of the cylinder will actuate the piston E forwardly to deliver its blow against the working implement P and the pressure fluid admitted into the.front end of the piston chamber will actuate the piston E to the rearward end of the piston chamber.

During the rearward movement of the piston the flutes Hill the extension F will be drawn into communication with the front end of the piston chamber and a portion of the pressure fluid acting against the forward surface of the piston will'then flow through the flutes H and through the chuck K into the drill steel during each-rearward stroke of the piston. This method is generally termed puff-blowing and in some instances the amount-of'pressure fluid thus'admitted to the drill hole may be sufficient to maintain a fairly clean rock face. lVhen drilling cer tain rock formations however, or when drilling holes of considerable depth the small amount of pressure fluidadmitted into the drill hole in this manner is often found to be insufficient to properly cleanse the drill hole. Cuttings will then accumulate around the drill steel rearwardly of the cutting bit where they form a collar and tend to retard the action of the rotation mechanism. In view of these factsit is desirable that means be provided to enable the occasional introduction of a large volume of pressure fluid into the drill hole for effecting a thorough cleansing thereof whenever the conditions hereinbefore related occur.

Various means have heretofore been devised for accomplishing this result. In sub stantially all instances however, the bore through the chuck parts forms a part of the conduit for conveying the pressure fluid to the bore in the working implement. \Vhen the parts are still new this method may not present any serious obj ectionsbut after some usage the parts become worn, particularly the bore 0 of the chuck which acts as a guide for the working implement. If then the pressure fluid is admitted into the chuck cavity a considerable portion thereof flows along the cooperating surfacesof the working implement and the chuck to the atmosphere without doing any useful work.

The present invention aims to assure a sealed connection between the source of pressure fluid supply and the working implement. To this end a tube 9 is disposed slidably in the back head h, the rifle bar U and piston E, and is provided at its forward end with a coniform surface r adapted to cooperate with a correspondingly formed seats at the rearward end of the bore Q of the working implement to form a seal'between the tubeand'the working implement. The rearward end of the tube 9 extends into a re cess 2f inthe back head handcarries aflange u, the rearward end of which serves as a pressure area 0), and the opposite end of the flange a as an end area 10 against which acts a spring a: seated with its opposite end against the bottom of the recess t.

The recess 25 is provided with suitable threads I to receive a threaded plug .2 whereby the recess t may be sealed. As an additional function the plug 2 also acts as a guide for the flange u of the tube 1. The plug is accordingly provided with a recess 2 into which the flange a slidably extends and said ecess serves as a supply chamber through which the pressure fluid flows into the tube. Such pressure fluid is admitted into the supply ehamberthrough ports 3 in the plug .2 communicat with the ports 0 in the throttle valve ...1rough a passage 4 in the back head It.

In structures embodying the form of the invention illustrated in the drawing, wherein the tube is intended to be retracted by spring pressure instead of by pressure fluid, the inner end of the recess i may be vented to the atmosphere through a passage 5 in the back head to pre ent the accumulation of such pressure fluid as may find its way beneath the flange it.

During the normal operation of the drill the throttle valve j will occupy the position in which the port 0 will be in registry with the passage Pressure fluid will then flow to the chamber 6 to be distributed to the ends of the piston chambe' by the valve (Z for actuating the piston. During this operation a portion of the pressure fluid will flow from the front end of the piston chamber to the bore in the working implement in the manner heretofore described.

In the event that the pressure fluid flowing through the flutes H to the bore Q, is found to be insufficient to effect a suitable cleansing of the drill hole the throttle valve j may be rotated to the position illustrated in the drawing in which the port 0 is moved into registry with the passage 4. In this position of the throttle valve communication between its interior and the distributing element is cut ofl so that the piston E will then be idle.

Upon the admission of pressure fluid into the passage 4 such pressure fluid will flow through the ports 3 into the supply chamber 2 and, inasmuch that the combined areas of the ports 3 are greater than the bore in the tube 9, the pressure fluid acting against the pressure area 1) will overcome the pressure exerted by the spring a" and move the tube downwardly until the coniform surface 1' is pressed into sealing relationship with the seat sin the working implement.

Pressure fluid may then flow through the tube and through the working implement under full line pressure until the drill hole is cleansed. After this effect has been obtained the throttle valve may be rotated to cut off the supply of pressure fluid to the supply chamber 2 and the tube 9 will then be retracted by the spring 00 so that the forward end of the tube will be moved out of contact from the working implement P during the subsequent operation of the hammer piston E.

From the foregoing description it will be evident that the present invention contains many desirable advantages. A few of these are that there will be no wastage whatsoever of pressure fluid during'the blowing operation and, that by retracting the tube 9 after blowing has been eflectedflhe tube will not be subjected to the abrading action of the working implement during the normal operation of the drill. The tube will therefore be capable of rendering service for aprolonged period of time since, as is well known, it is at the forward end, that is, the part which comes into contact with the working implement where the tube is usually first rendered unserviceable through wear.

I claim: 7

1. In a fluid actuated rock drill, bination of a cylinder and a hammer'piston therein, a drill steel to receive the blows ot' the piston and having a bore, a back head having a recess; a tube for conveying pressure fluid from the recess to the bore and extending into the recess, and a pressure area on the tube adaptedto be exposed to pressure fluid for eflecting movement of the tube toward the drill steel.

2. In a fluid actuated rock drill, the combination of acylinder and a'hammer piston therein, a drill steel to receive the blows of the hammer plston and havlng a bore, a back head having a recess, a tube for conveying pressure fluid from the recess to the bore and extending into the recess, a flange on the tube having opposed end areas, means for selectively exposing one end area to pressure fluid for effecting endwise movement of the tube in one direction, and a spring acting against the other end area for efl'ecting endwise movement of the tube in the opposite di-. rection.

3. In a fluid actuated rock drill, the combination of a cylinder and a hammer piston therein, a drill steel to receive the blows of the piston and having a bore, a back head having a recess, a tube for conveying pressure fluid from the recess to the bore and extending into the recess, a flange on the tube having opposed end areas, means for supplying pressure fluid to the tube and for exposing one end area to pressure fluid for pressing the forward end of the tube against the drill steel, and a spring acting against the other end area to normally hold the tube out of contact from the drill steel.

4. In a fluid actuated rock drill, the combination of a cylinder and a hammer piston therein, a drill steel to receive the blows of the piston and having a bore, a back head the com- I having a. recess, a tubefor conveying pressure fluld from the recess to the bore, a plug forminga closure for the recess and having a supply chamber tliereim means for, selectively admitting pressure fluid intoothe supe ply chamber and throughthetube into the borepa flange, on the tube disposed in the supply chamber and having a pressure-area at its rearward end exposed to pressurefluid for pressing the tube against the drill steel during the blowing period, and a spring acting against the forward" end 01 the flange for retracting thetube upon the cut-off of pressure fluid'to the supply chamber.

.5. lln. afluld actuatedrock drill, the combination of a cylinder and a hammer piston. therein, a drill steel to receive the blows of the pistonand having a bore, means includ- 1 ing a distributing valve for distributing pressure fluid to the cylinder, a back head having a recess, atube slidable relatively to the cylinder and affording communication between the recess and the bore, a flange on the tube disposed in the'recess and. having a pressure area adapted to be exposed to pressure fluid head having a recess, a tubefor conveying pressure fluid from the recess to the bore, a flange on the tube disposed 1n the recess, means acting against one end. of the flange for normally holding the tube in retracted position, and means for selectively exposing the other end of the flange to pressure fluid for holding the forward end of the tube in sealing relation with the drill steel while simultaneously supplying pressure fluid to the bore. 7. In a fluid actuated rock drill, the combination of a cylinder and a hammer piston therein, a drill steel to receive the blows of the hammer piston and having a bore, a back head having a recess, a tube for conveying pressure fluid from the recess to the bore, a flange on the tube dis posed in the recess, a spring acting against one end of the flange for normally holding the tube in retracted position, and means for selectively exposing the other end of the flange to pressure fluid for holding the forward end of the tube in sealing relation with the drill steeel while simultaneously supplying pressure flui-d to the bore.

8. y In a fluid actuated rock drill, the combination of a cylinder and a hammer piston therein, a drill steel to receive the blows of the piston and having a bore, a back head having a recess, a tube for conveying pressure fluid from the recess'to the bore and extend ing into the recess, a pressure area on the tube adapted to be exposed to pressure fluid for pressing the forward end of the tube against the drill steel, a valve for selectively admitting pressure fluid t0 the cylinder for actuating the piston and to the pressure area for actuating the tube, and means for normally holding the tube out of contactfrom the drill steel.

9. In a fluid actuated. rock drill, the combination of a cylinder and a hammer piston therein, a drill steel to receive the blows of the hammer piston and having a bore, a back head having a recess, a tube for conveying pressure fluid from the recess to the bore and extending into the recess,.a pressure area on the tube, means for selectively admitting pressure fluid to said pressure area to effect end- Wise movement of the tube in one direction, and means for efi't'ecting the reverseniovement of the tube upon the cut-o-li' of the admission of pressure fluid to saidpressure area.

In testimony whereof I have signed this specification.

PETER A. XVILLIAMS.

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