US2777424A - Automatic water valve for rock drills - Google Patents

Description

Jan. 15, 1957 G, FUEHER 2,777,424

AUTOMATIC WATER VALVE FOR ROCK DRILLS Filed Nov. 16, 1953 2 Sheets-Sheet 1 O V .l 8. y@

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@freeway I Jan. 15, 1957 G. H. FUEHRER 2,777,424

AUTOMATIC WATER VALVE FOR ROCK DRILLS United States Patente@ 2,777,424! Y AUTOMATIC WATER VALVE EUR fRCflCKL-DRILLS.l

George H. Fuehrer, Downey, Calif., assignor to Thor Power Tool Company, Aurora,- lIll.,` a corporation of Delaware Application November 16, 1953SerialiNo. 392,134 Y 6 Claims. (Cl. 12-1'10)"A This invention relatesr to` fanautomatic. water valve which is operable to start4 or stop the feed of-:water to the cutting bit of a rock drillingI apparatus without the necessityof moving any` controlknobs, handles, or levers of any sort. i

In automat-ic rock drillingapparatus, .forfexample the stopers, sink'ers, and drifters Ausediformining and;' -tunn eling operations, it is conventional practice) to feed Water to thel cutting bit as the drilling` progresses y The pur.- pose of the-water is to eifectcontinuous.cleaning or blowing of thejh-ole, sotha'tthe drills-teeth always engageand act on the holebottom insteadiofyon chips or fragments previously broken fromy -thefmain body ofthemass beingv drilled. The' feeding ofV iwater .toutheghole "bottomy hasI the additional Iand veryimportant purposeof eliminating the dust which is extremelyfdangerousand-otherwise unf desirable in 'a mine-or tunnel.:

During the full-speed drilling operatiomdtheuwater feedworks no hardship onza;A miner since he; isxthenable.- yto standwell yaway from :the -hole; and is ano-trshowered,` or splattered with the* waterfandrmuck: inherent ,inthel operation. However, lthezfeeding ofwater during other portions of 'the drilling operation may'resultiinaconsider.-

able hardship to the operatorwhois ythen.rlrenchedfwith,v

water and muck. This Ais particularly true'when the operator vis forming a coll-infor.. starting hole, IatwhichA time the drill motor is operating relatively slowly and the operatorV must standy close to the drill. biti infordark to guide it. f

I-n appreciation of the fact that itis often undesirable to feed water to the drill bit during the lstarting orcollaring operation, certain mining companies require that an automatic water valve be so designed that it` =will shut loff the ow of water during collaring butwwill permit water flow during full-speed drilling. Other companies, on the other hand, require automatic water valves whichy effect the flow of water at all ,times when thedrillvmotory is operating, including `duringthe collaring operation. lt may be seen, however, that the presence orv absence of water flow during collaring and'similar operations is not a matter which can be determined for large lnumbersy of operations and all situations, lbut instead is one which will vary with thetype of rock being drilled,'|the `location and angle of the drill, and otherrfactors which can onlybe determined by the operator. Although this fact is Awell recognized, the complexity and* fragility of au-tomatic water valves which permit the drill operator'to selectively start and stop water ow during the collaring operation, :or other similar operations,y has previously prevented their acceptance and use-on commercial drilling apparatus `of the type indicated.

In view of the abovefactors characteristic -offthe field of automatic water valves for rock drills,-` -it is aniobject of the present invention yto provide an iextremelylsimple and rugged means for. yselectively startingand. stopping the iiow of water to the drill bit duringone of severaly types of drilling operations.

Another object of theinvention .isrto provide. ausystemf.;

' backhead vof an offsettelesoopic feedileg s-toper incor- 2,777,424 yPatented Jan. 15, 1957 by which the operator may start Iand Istop water ow without moving any handle or knob, but instead, by mere'- ly placing-his iingerwover a vent holeA or removing Ait therefromr,

An additional yobject is to providefan automaticwater valvefassociated with` the drill throttle valvev and which in ysome throttle valve positions isfcontrolled bothby the throttle valve and. byanoperater-controlled,vent, and, in other throttle valve positionsr is controlledbytheythrotitlevalvealone.

vOther-objectsand; advantages of the invention; ywillbe more,Q 4fully set forthvin thev followingspecificatione and. claims considered in conneotionwith therv attached drawings *to which `they relate.

Figure; 1 'is a vertical central sectional viewof the porating the present invention', the throttle valve andautomatic watervalvebeing shown as connected by passage means in the backhead; f.

Figure 2 is' ayhorizontal sec-tional view taken along line yJZ-.Zof Figure l and looking in the. directionof the arrows, both it and Figure l showing the drill throttle valve in its-collar or starting holeposition;

'Figure .3 illustratesthe automaticwater valve of Figure lA fasnshifted* from its closed to its ,-open position;

FiguresA, Sand 6 lare sectional views taken along line;l 4--4' of ,Figure 2 and showing the throttle valve in its collarrfull. throttle andoiy positions, respectively; Figures 7` and\8 are sectional views of the throttle valve andiasshown-inFigurelI but illustrating, respectively, the throttle valve afterfshiftingfrom the collan'ngposi tionfofFigurevl to the full throttle and of positions.

Referring tothey drawings, thelinvention is illustratedt' as `employed in `the ybackhead 10 of -an automatic rock f l drillingapparatus ofthe Ioffset telescopic feed legstoper type. Associfatedwwi-th: the backhead 10 are the automatic water valve 11 and the throttle valve 12, the construction andoperation of which will be described in detail subsequently. Also associated with the backhead isfanarm13 connectedtothe yoffset feed llegwhich is indicated Ffragment'arilyat 141in Figure l.

Watervalve ll'preferably comprises a plug-like casing llthreaded into Ia recess 17which communicates with the water tube r'18, -theflatterextendinglongitudinally' through the drill body, not shown, to the drill steel and cuttingbit. In the lembodiment illustrated, |the recess17 isformed in -a plug or cap member 19 which` is suitably mounted on the rear surface of backhead 10 and is shapedfwitha cylindricalfboss 21y jsealingly seated in a` correspondingbackhead recess 22. The casing 16, con# taining the (pistone-and'plug components offthe water valve aswill vnextbe described, -is removable to permit replacement of water 'tube' 18z when necessary, and is inten. changeable with the conventional watery tube plugfound on rock drills ofthe type indicated.

Casing .16'. contains a piston plunger 23 ywhich is no-rmally-l urged: forwardly by a. compression spring. 24 to thepositionshownin Figure l, at which its pointed or conical; innerend 26 is pressed against. a resilient seat washer,2'7: to cflosethe end of Water tube 18; To shift the piston plunger 23'rearwardlyffrom the-closedzposition shownf'invFigure l toftheiopcn position ofI Figure'2and' thusstart1the flow of water-tothe cuttingbit, air is admitted to anair'chamber 28 the rear wallsofwhichare formed? byboss or flange portionsof piston plunger 23. TheOWof water isfroma water chamber generally in l backhead recessf22and sealed by sealing rings 29; the

chamber being fedy withfwater from= a suitable supply, source,A notl shown. Forf amore complete description of the watervalve 11, particularly with :reference toits pas-y sage,- sealingandventn1eans5y reference is made to my co-pending application Serial No. 355,679, filed May 18, 1953, for an Automatic Water Valve for Rock Drills, and which is now Patent No. 2,728,328, issued December 27, 1955.

The throttle valve 12 comprises a tubular valve sleeve 31 which is mounted in a corresponding transverse bore in the lower portion of` baekhead and is adapted with a handle 32 for rotation to its various controlling positions. As shown in Figure 2, one end of valve sleeve 31 is closed and is provided with a relatively small diameter stern 33 on the outer portion of which the handle 32 is mounted as by a lock nut 34.V The other end of the valve sleeve is connected to an air supply hose, not shown, to elfect a constant feeding of air pressure to the chamber 36 within the sleeve. Referring to Figures l, 7 and 8, valve sleeve 31 is provided with a port 37 adapted to register with a backhead passage 38 leading to the distributing valve and piston hammer of the drill. When the throttle is in the position shown in Figure 1, port 37 is only partially registered with passage 38and the drill motor is accordingly operated relatively slowly to form the starting or collar hole. In Figure 7, on the other hand, the port 37 and passage 38 are shown in the fully registered or full-throttle positions, while in Figure 8 these elements are shown in their` unregistered or olf positions.

For a more complete description of the elements operated by the air passing through port 37 and passage 38, reference is made to my co-pending application Serial No. 379,207, led September 9, 1953, for a Pneumatic Rock Drill with Selective Drill Steel Rotation, and which is now Patent No'. 2,726,640, issued December 13, 1955. That application also contains a complete description of the rotation release valve 39 (Figure 2) which is mounted on valve stem 33 but is movable independently of it. The valve 39 is operable to selectively startand stop drill steel rotation as may be desired by the operator of the apparatus.

According to the present invention, means are provided to associate the throttle valve 12 and water valve 11 in such a way that the latter is always closed when the throttle valve is in the off position shown in Figure 8, and is always open when the throttle valve is in the fullthrottle position shown in Figure 7. However, in the collar or any other intermediate throttle valve position, the operator may selectively open and close the water valve 11 by merely placing his iinger over the end of a vent or bleed passage 41 which preferably terminates in a replaceable restrictormeans 42 at the outer end of valve stem 33. The location of the end of vent passage 41 at the end of valve stem 33 is very desirable since the drill operator may, with one hand, turn the throttle valve handle 32 and the rotation release valve 39, and selectively block or open the bleed passage.

The specific air passages and ports for connecting the water and throttle valves 11 and 12 and vent or bleed passage 41, in order to accomplish the above results, comprise first and second arcuate grooves 43 and 44 on the external surface of valve sleeve 31, and a generally U-shaped backhead passage 46 the ends of which are adapted to register with the grooves 43 and 44 when sleeve 31 is in predetermined rotated positions. Groove 43 communicates through a passage or port 47 with valve chamber 36, and groove 44 communicates with an obliquely extending portion 48 of bleed passage 41. The U-shaped passage 46, which lies in a horizontal plane, communicates through an upwardly extending passage 51 in backhead 10, a passage 52 in plug or cap member 19, and a passage 53 in water valve casing 16 with the air chamber 28 inwardly adjacent the llange portions of piston plunger 23. The connections between passages 51, 52 and 53 include annular grooves 54 and 55 which cause the passages to be in communication regardless of the relative rotated positions of the abutting elements.

The lengths and locations of arcuate grooves 43 and 44 are such that both will be out of registry with U- shaped passage 46 when throttle valve 12 is in the off position shown in Figures 6 and 8. The water valve 11 will then be in the closed position shown in Figure 1, since the ow of air pressure from valve chamber 36 to air4 chamber 28 is effectively blocked and the compression spring 24 is operative to seat plunger end 26 on seat washer 27. When, however, the handle 32 is turned to rotate throttle valve 12 to the full-throttle position shown in Figures 5 and 7, groove 43 is registered with U-shaped passage 46, but groove 44 is stillout of registry therewith. It follows that air then ows from valve chamber 36 through port 47, groove 43, U-shaped passage 46, and passages 51, 52 and 53 to air chamber 28. The air pressure in the air chamber 28 is thus increased to force piston plunger 23 rearwardly against the bias of spring 24 and to the unseated position shown in Figure 3, so that tlow of water through water tube 18 to the drill bit is permitted. It will be noted that the air pressure in air chamber 28 is allowed 'to build up since there is no vent or bleed from U-shaped passage 46 to vent passage 41, the groove 44 and passage 46 being out of registry at this time as previously indicated.

At all or substantially all intermediate throttle valve positions, for example the collar position shown in Figures 1 and 4, both of the grooves 43 and 44 are registered with U-shaped passage 46, and a path is created from valve chamber 36 both to the air chamber 28 and to the vent or bleed passage 41. While the bleed passage 41 is open, air will bleed off and the air pressure in chamber 28 will not build up to a value sufcient to shift piston plunger 23 rearwardly. The blocking of bleed passage 41 by an operator pressing his finger against restriction means 42 will, however, prevent further bleeding and will cause the air pressure in chamber 28 to build up and effect rearward piston shifting until the water valve is open as shown in Figure 3. It follows that the operator may selectively open and close the water valve, during collaring or any other intermediate throttle valve position, by merely pressing his finger against restrictor 42 or removing it therefrom. The diameter' of the bore in restrictor 42 is substantially the same as the diameter of port 47. It follows that the rate of bleed is approximately equal to the rate of air feed to the Water valve, So that air pressure in the Water valve will not build up until the bleed passage is blocked.

To briefly summarize the operation of the automatic water valve, let it be assumed that throttle valve 12 is in the off position shown in Figures 6 and 8, at which time the flow of air from valve chamber 36 to water valve l1 and to bleed passage 41 is blocked. The spring 24 is then operative to hold the piston plunger 23 against seat washer 27 and block the flow of water through tube 18 to the drill bit. Should the operator then desire to form a starting or collar hole, he stands relatively close to the drill bit and turns throttle valve handle 32 to rotate valve sleeve 31 to the collar position shown in Figures 1 and 4. Chamber 36 then communicates through U-shaped passage 46 both with air chamber 28 and vent passage 41, so that the operator may eti-ect shifting of water valve plunger 23 rearwardly to its open or Figure 3 position merely by placing Ihis finger on restrictor 42 at the end of the vent passage. In normal operation, the operator Will only cause water flow to the extent necessary to eliminate dust, since a continuous flow of water is undesirable at this time due to the location of the operator `close to the drill steel where he is subject to being showered with water and muck. After the collar hole has been formed, the operator turns throttle valve 12 to the full-throttle position shown in Figures 5 and 7, and steps back away from the drill steel where he is not likely to be contacted by the water and muck inherent in the operation. The flow of water at this time is continuous since a path is formed from valve chamber 36 to air chamber 28 but the vent through bleed passage 41 is blocked, the groove 44 and U-shaped passage 46 being out of registry as shown in Figure 5.

Throughout the application the structure 11 has been referred to as the water valve since it contains the valve plunger, etc. lt will be apparent, however, that the entire water valve comprises not only the structure 11 but the bleed passage 41 and all of the passages interconnecting throttle valve 12 and the structure 11.

While the particular apparatus herein 'shown and de scribed in detail is fully capable Iof attaining the objects and providing the advantages hereinbeore stated, it is to be understood that it is merely illustrative of the presently preferred embodiments of the invention and that no limitations are intended to the details of construction or design herein shown other than as `defined in the appended claims.

Iclaim:

1. In a water valve for pneumatic drilling apparatus, a valve element including an actuating piston movable between a position permitting the flow of water to the drill steel of said drilling apparatus anda position blocking water tlow thereto, means to admit air under pressure to a chamber adjacent said Valve element and housing said actuating piston to effect shifting `of said piston and valve element to one of said positions, and means to vent said air pressure to the atmosphere during the period of its admission to said chamber, said vent means having a cross-sectional area suiciently large to prevent said air pressure from building up to a value sucient to etfect valve element shifting to said one position, the discharge end of said vent means being disposed to facilitate blocking thereof by the operators linger to effect shifting of said valve element to said one position, said vent means being operatively associated with said throttle valve of lsaid drilling apparatus, and means associated with said throttle valve to block said vent means continuously when said throttle valve is in a predetermined controlling position.

2. In a water valve for a pneumatic rock drilling apparatus having a water passage leading to the drill steel of the apparatus, means forming a piston chamber, a valve piston mounted in said piston chamber and movable between opened and closed positions at which water ow through `said passage is respectively permitted and blocked, means to bias said piston to said closed posi tion, conduit means to conduct air pressure to said piston chamber to move the piston and open said valve against the action of said bias means, and vent means to bleed air from said conduit means and from said piston chamber, said vent means being suthciently large to prevent building up of a pressure adequate to shift said piston to said open position, said vent means having a discharge end disposed to permit blocking thereof by the operators nger, and means associated with the throttle valve of said drilling apparatusvalso operable to block said vent means at a point intermediate said piston chamber and said discharge end when said throttle valve is in full throttle position.

3. An automatic water valve system for a pneumatic rock drilling apparatus having a water tube adapted to deliver water to the drill steel of said apparatus, which comprises a piston plunger mounted at Ithe backhead of said apparatus and adjacent the end of said water tube, said piston plunger being movable between open and closed positions respectively permitting and blocking the ow of water through said water tube, a compression Ispring mounted on one side of said piston plunger and adapted to bias the same toward said closed position, means to define an air chamber one wall of which comprises the yother side of said piston plunger, a throttle vaive mounted in said backhead lto control the flow of air from a source of air pressure to the distributing valve and piston hammer of said apparatus, a Vent passage terminating in an outlet orifice to the atmosphere; and means in said throttle valve and backhead `to interconnect said air chamber, said vent passage and sai-d air pressure source when said throttle valve is in collar position, and to connect said air pressure source and air chamber but -to block the flow of air through said vent passage when said throttle valve is in full-throttle position.

4. The invention as claimed in claim 3, wherein the last-named means comprise a throttle valve sleeve having first and second grooves therein and forming a valve chamber connected to said air pressure source, a port in `said sleeve and connecting said valve chamber and said first groove, passage means adapted to selectively register with said first and second grooves and connected to said air chamber, and means to connect said second groove and said vent passage, said grooves being so related that both register with said passage means when the throttle valve is in collar position, but only said first groove registers with said passage means when that throttle valve is in fullthrottle position.

5. The invention as claimed in claim 4, wherein said port and said outlet orice are relatively small and of approximately the same diameter.

6. The invention as claimed in claim 3, wherein said throttle valve is formed with a stem terminating in a control handle, said vent passage is through said stem, and said outlet orifice is adjacent said control handle.

References Cited in the tile of this patent UNITED STATES PATENTS 787,705 Templin Apr. 18, 1905 1,845,805 Nell Feb. 16, 1932 2,205,736 Schorle .lune 25, 1940 2,215,217 Gustafson Sept. 17, 1940 2,678,056 Ditson May 11, 1954

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