US1789698A

US1789698A - Valve for rock drills

Info

Publication number: US1789698A
Application number: US421164A
Authority: US
Inventors: John C Curtis
Original assignee: Ingersoll Rand Co
Current assignee: Ingersoll Rand Co
Priority date: 1930-01-16
Filing date: 1930-01-16
Publication date: 1931-01-20
Anticipated expiration: 1948-01-20
Also published as: GB359779A; DE553372C

Description

Jan. 20, 1931. .J-.' c. CURTIS 1,789,698

VALVE FOR ROCK DRILLS FiledJah. 16. 1930 VENTO ziolm a cuf zis. R

HIS ATTORNEY or shock which usually takes place in ma Patented Jan. 20, 1931 "-UNITEDSTATES PATENT 'oFF1cE7- I]*- JOHNY'CPCURTIS, or msron, PENNSYLVANIA, nssranon 'ro xnennsonnnann an rm, or JERSEY an NEW EBSE A conromwronor NEW JERSEY I VALVE on nocx nmnns Application med J'anuaryi'lB, 1930; seriarne. 421,164.

This invention relates to rock drills, but more particularly to a distributing valve for rockdrills of the fluid actuated type.-

The objects of the invention are to obtain a quick and positive action of the valve, to

assure a heavy blowof the hammer piston against the working implement, and to con- 1 trol the supply of pressure fluid to the ends of the piston chamber in such manner that the hammer piston will strike heavily against the working implement on its forward stroke and that the hammer piston is actuated rearwardly without causing theobjectionable jar chines of this character. w 4

Other objects willbe in part'obvious and in partpointed outhereinafter: A

In the accompanying drawings forming part of thisspecification and in which similar reference characters refer to similar p v Figure 1 is a sectional elevation of a-rock drillequipped with a valve constructed in accordance with the practice of the invention, thevalve being shown iii-position to supply pressure fluid to the rearward end of the piston chamber, and V Figure 2 is v a similar view "showing the valve in a position to supply pressure fluid to the front end of the pistonchamber. Referring more particularly, to the drawingsA designates generally arockd'rill comprising a cylinder B wherein is formed 'a piston chamber C to accommodate a reciprocatory hammer piston D. In the wall of the cylinder B is a piston controlled exhaust port E to afford communication between the piston chamber C and the atmosphere.

A suitable closure is provided for the front end of the piston chamber C in the'form of a head F which may also act as a guide for a working implement G shown as extending withits rearward end into the piston chamberto receive the blows ofthe hammer pistonD. I

A closure is provided for the rearward end of the piston chamberin the form ofa plate H whereon is seated a head block J which in turn serves as a seat for a back head The cylindervB, t ehead F and the elements d ignated by H, J and K form the casing m of the rock drill and such parts may be held in assembled relationship in anysuitablef'and conven ent *nianner, as for instance, usual side bolts (not shown). I

vention the head'block'J is provided witha bore=L toreceive a valve chest 0 having a e The valve s m be provided with e recess or cavlty U to reduce its weight; 'Ne'arithe 7 forward end of the valve is an integralflange Vwhich lies in the enlarged portion Q and spaced slightly 'rearwardly of the'fl'ange is another flange W'which also lieswithinyt'he enlarged portion Q.

by the V In accordance with the practiceof thein- The pressure fl idintended to be die} tributedby the'valve is'introduced between 1 the flanges V and 'W by a port orports'X municate with a supply conduit Y through an annular passage Zin the head block J." if

The pressure fluid utilized for impelling thepiston D forwardly is admitted into the in the valve chest O and the ports -X comrearward end of the piston chamber C through a rear inletpassageb in the plate I and coaxially with the valve S, Thepressure fluid utilized for driving the pistonD rearwardly is conveyed to-thelfront end of the piston chamber by a front inlet passage 0 which extends through the cylinder B, the plate H and the head block J and'communicates with the rearward end of the enlarged.

portion Q, of the valve chamber through ports d in the valve chest 0.

In the flange V are a series of ports 6 through which the pressure fluid flows to the rear inletjpassage b andthe pressure fluid supplied to the front inlet passage 10 flows through, ports f in theflange Theports e are preferably of greater area than vthe ports so that a greater amount ofpressure fluid maybe supplied to the rearward end Of: the piston: chamber within a ,given time than to the front end. -This is desirable for the reason that the forward stroke of the piston is the working stroke. Convenient means are provided for actuating the valve S from one limiting position to the-other. To tlllSBDCl the flange'V is provided at its forward end withan annularpressure area 9 against which the pressure fluid flowingthrough the ports a may, act to'throw the valve rearwardly. Similarly a pressure area h is formed on'the rearward'end of the flange W so that pressure fluid flowing through the ports f will act thereagainst to throw the valve to its forward limiting position. p

Additional means are, however; provided to assist the pressure fluid'acting against the pressure areas 9 andh in throwingtheiyalve. The valve is accordingly provided with an 6 actuating surface 7' against wliichwomp'ression from the rearward iendvofthe'= piston chamber may act'to assist:thexpres'surefluid.

to the rear end of the piston-chamber-C to assist the. forces actingagainst' the a ctuating surface 72 and the pressure surface'hto move the valveS forwardly. Thepressure fluid is, suppliedto the actuating surface owby a port 39 in the end wall'Q of the valvewS.

. In order to assure an immediate:- drop in the pressure fluid acting against the actuating surface 0 after the valve S has been moved forwardly, the valve chamber P: isproVijded with an exhaust passage 1 which "leads through the valve chest 0 and the head block to the atmosphere and is controllediby the rear end of the stem: T. TheeX-ha-ust passage r is preferably so locatedthat it will be only uncovered bythe-stem T of the-valve when the valve reaches its foremost'position in the valve chamber P.

The operation ofthe device is as follows: With the valve in the rearmost position illustratedin Figure 1 pressure fluid will flow through the ports 6 intoan'd through the front end of the valve chamber Pjthence throughthe rearinlet passage Z; into the back end of the'piston chamber to drivethe piston D forwardly. V V

During the admission of pressure 'fl'uid into this end of the'piston chamber pressure fluid will also pass through the port 19 in the end wall g of the val'veto act against the'actuating surface 0. "At'the' same time pressure fluid will be acting against the pres sure surfaces h and g and against the actuating surface y'.

Inasmuch that the actuating surface will be exposed to atmospheric pressure through -the inletipassagecythe pistoncham- I ber C and 'the exhaust port Eythe areas eX- posed. to pressure fluid for holding the'valve rearwardly will be somewhat in excessof those 'exposed 'to pressure fluid tending to throw the'valve" inthe oppositedirection.

Thepiston D will then continue forwardly and at'the" instant the rear end of the piston D .startswto.uncovervtheiexhaust port E there will be a decided drop in pressure against the pressure Earea g and theactuating, surface jsoi'thatthe pressures "acting against the pres? v sure areahand: the actuating surface 0 will immediately :start *the .valve forwardly. After'it-he valve starts in-this direction ,the actuating, surface 70 will also be -.exposed" to pressure fluid so that the valvewill be quickly moved I forwardly where 1 it will be held by the-pressure acting againstthe pressure area h and'the actuatingsurface k. I 1

JASIhB valve Sapproaches itsforemost sition-inthevalve chamber P .theexhaust passage riwillbe uncovered by the stemT ofthe valve and the pressure'fluid which previously acted againstthe actuating surface "96 0 will then be exhausted to the-atmosphere.

This forward movement Qof .the 'valve v will take;place.at aboutthe timetthe piston delivers *it'sf blowf'to the working I implement. In the new position of, the valve pressure fluid will flow through the ports f, the'ports (Land the front inlet passage '0 to thefront end of: the-piston'chamber O to actuate the piston-.Drrearwardly.

After the. exhaust portlEis coveredby the exhaust port E; The valve will then be -held in "its: rearrnostposition by'the pressures acting-"aaainst the entire front area of the r valve as well as against the actuating surface j. rI lclaimz' 1. In-a fluid-actuated rock drill, the combination of a 'cylinderhavinga piston chamber and a piston in the piston chamberganbxha-ust port in the cylinden avalve c-hest haw ingi a valve chamber, inlet passages-leading fromtheends of the valve chamber to the pistoncha'mber, a valve in thevalve-chambercon? trolling the inlet passages and having a pairof flanges, a supply passage in the valvechestfor supplying pressure fluid to the valve chamber between the flanges, pressure areas" on the flanges, ports in the flanges 1:01 supplypressure fluid to the pressure areas-and to the'inlet passages, and opposed actuating surfaces on the valve, one of said actuating surfaces being intermittently exposed to pressure fluid to assist the pressure fluid acting against one pressure area to throw the valve in one di- V rection and the other actuating surface being intermittently exposed to compression to assist the pressure fluid acting against the other pressure area to return the valve.

2. In a fluid actuated rock drill, the combination of a cylinder having a piston chamber and a piston in the piston chamber, an exhaust port in the cylinder, a valve chest having a valve chamber, inlet passages leading from the'ends' of the valve chamber to the piston chamber, a valve in the valve chamber having a pair of flanges, annular pressure areas on the flanges, ports in the flanges to supply pressure fluid to the pressure areas for throwing the valve and to supply pressure fluid to the inlet passages, a supply passage in the valve chest to introduce pressure fluid into the valve chamber between the flanges, a hollow stem on the valve and having an end wall to form opposed actuating surfaces, one of said actuating surfaces beingintermittently exposed to compression to assist in I throwing the valve in one direction, and a port in the end wall supplying pressure fluid to the other actuating surface to assist in throwing the valve in the opposite direction.

3. In a fluid actuated rock drill, the combination of a cylinder having apiston chamber and a piston in the piston chamber, an

exhaust port in the cylinder, a valve chest having a valve chamber, inlet passages leading from the ends of the Valve chamber tothe piston chamber, a valve in the valve chamber having a pair of flanges, annular pressure areas on the flanges, ports in the flanges to supply pressure fluid to the pressure areas for throwing the valve and to supply pressure fluid to the inlet passages. a supply passage in the valve chest to introduce pressure fluid into the valve chamber between theflanges,

a hollow stem on the valve and having an end wall to form opposed actuating surfaces, one

of said actuating surfaces being intermittently exposed to compression to assist in throwing the valve in one direction, a port in the end wall to supply pressure fluid from the rear end of the piston chamber to the other actuating surface to assist in throwing the valve in the other direction, and an exhaust port leading from the valve chamber to the atmosphere and controlled by'the stem to exhaust the fluid acting against the last said actuating surface.

In testimony. whereof I have signed this specification.

JOHN C. CURTIS.