US1828491A - Valve for rock drills - Google Patents

Description

patented et. 20,1931

PATENT OFFICE UNITED: STATES JOHN c'. cuE'rIs'or EAsroN, PENNSYLVANIA, ASSIGNOR T0 INGERSOLL-BAND COM- IPANY, or EsEY' CITY, NEW JERSEY, A CORPORATION or nEw JERSEY VALVE r03 noon DRILLS Application filed November 1, 1929. Serial No. 404,010.

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

The objects of the invention are to obtain a quick and positive action of thevalve, to assure aheavy blow of the hammer piston against the working implement, and to control 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 onits forward stroke and that the hammer piston is actuated rearwardly without causing the objectionable jar or shock which usually takes place in machines of this character.

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

In the accompanying drawings forming part of this specification and in which similar reference characters refer to similar parts, t

Figure 1 is a sectionalelevation of a rock drill equipped with a valve constructed in accordance with the practice of the invention, the valve being shown in position to supply pressure fluid to the rearward end of the piston chamber, and a p 7 Figure 2 l .is a similar view showing the valve in a position tosup'ply pressure fluid to the front'end of the: piston chamber.

Referring more particularly to the drawings, A designates generally a rock drillcom= prising a cylinder B wherein is fo'rmed a piston chainber C to accommodate a'reciproca- I toryhammer 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 chamberC in the form of a head F which may alsoactas a guide fora working implement Gr shown as extending with its rearward, end'into the piston chamber to receivethe blows of the hammer piston A closure isprovided for the rearward end ofthe'pistoncham'ber in the form of a plate jH whereonis seated at head block J which in turn serves as a seat for a back head K.

The cylinder B, the head F and the elements designated by H, J and K form the casing parts of the rock drill and such parts may be held in assembled relationship in any Sllltflblfi and convenient manner, asfor instance, by .the usual side bolts (not shown). In accordance with the practice of the in 'v'entionthe head block J is provided with a bore L to receive a valve chest 0 having a bore to form a valve chamber P. The Valve chamber P comprises an enlarged portion Q and a reduced portion R to accommodate a distributlng valve S having a hood or stem "T which extends slidably into the reduced portion R to form a bearing portion for the valve. -The valve S cess or cavity U to reduce its weight. Near the forward end of the valve is an integral *fla'nge V which lies in the enlarged portion Q and spaced slightly rearwardly of the flange V is another flange WV which also lies "within the enlarged port-ion Q.

The pressure fluid intended to be distributed by the valve is introduced between the flanges V and W by a port or ports X in the,

valve chest 0 and the ports X communicate with asupply conduit Y through an annular'passage Z in the head block J.

The pressure fluid utilized for impelling the piston D forwardly is admitted into the rearward end of the piston chamber C through a rear inlet passage Z) in the plate H and coaxially with the valve S. The pressure fluid utilized for driving the piston D 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 may be provided with a re rearwardly is conveyed to the front end of portion Q of the valve chamber through ports (Z in the valve chest 0.

In the flange V are a series of ports 6 through which the pressure fluid flows to the rear inlet passage 6 and the pressure fluid supplied to the front inlet passage 0 flows through ports f in the flange WV. The ports are preferably of greater area than the ports f so that a greater amount of pressure fluid may be 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 this end the flange-V is pro-' vided at its forward end with an annular nressure area against which the pressure fluid flowing through the ports 6 may act to throw the valve rearwardly. Similarly a pressure area it is formed on the rearward end of the flange W so that pressure fluid flowing through the ports 7 will act thereagainst to throw the valve to its forward limiting position. 7

Additional means are, however, provided to assist the pressure fluid acting against the pressure areas 9 and h in throwing the valve.

The valve is accordingly provided with an actuating surface against which compression from the rearward end of the piston chamber may act to assist the pressure fluid acting against the pressure area 9 to-throw the valve rearwardly. At the rearward end of the flange V is an annular actuating surface [13 which is subjected to compression from the front end of the piston chamber 0 to assist the pressure fluid acting against the actuating surface 71- in throwing the valve forwardly. Preferably the rearward end of the reduced portion B of the valve chamber is 3 vented to the atmosphere, as for instance, through the through a passage 0 which leads valve chest 0 and the back head K. g

The operation of the device is as follows:

With the valve in the rearward position ilpressure fluid will flow lustrated in Figure 1, through the ports 6 into and through the front end of the valve chamber P and thence through the rear inlet passage 6 into the back end of the piston chamber to drive the piston D forwardly. the pressure fluid through the front end of the piston chamber, such pressure fluid will act against the pressure area 9, as Well as the actuating surface 7', to hold the valve S rearwardly. At the same time, however, pressure fluid will flow through the ports and the flange W to act against the pressure area it of the flange V. But, owing to the fact that the entire forward surface of the valve is exposed to pressure fluid" and this area is considerably greater than the pressure area 7L,

During the passage of the valve will remain in its rearward position.

As the piston D continues forwardly the air in the front end of the piston chamber 0 will be compressed thereby and such compression flowing through the inlet passage 0 will then act against the rearward actuating surface is, so that immediately after the piston D uncovers the exhaust port E and at which time there will be an abrupt drop of pressure acting, against the forward. end of the valve, the pressure fluid acting against the pressure area it and the compression acting against the actuating surface 7c will throw the valve forwardly; c

In the new position of the valve, pressure fluidwillflow from between the flanges V and W through the ports f and through the enlarged portion-Q- cf the valve chamber into the ports (Z and thence through the inlet passage 0 into the front end of the piston cham ber to return the piston to its initial posi tion. As'during the forward stroke, the piston D will compress the air in the front end of the piston chamber and such compression will act against the actuating surface j to sist the pressure fluid acting against the pressure area 9 to again throw the valve rearwardly.

I claim:

1. In a fluid actuated rock drill, the com-- bination of'a' cylinder having a piston chamber and a pistonin the piston chamber, an exhaust port in the cylinder, a valve chest having a valve chambeninlet chambers leading from the endsof the valve chamber to the piston chamber, a valve in the valve chamber controlling the inlet passages and having a pair of flanges, a supply passage for supplying pressure tl'uid to the valve chamber between the flanges, pressure surfaces on the flanges, ports in the flanges to supply pressure fluid'to the pressure surfaces for throwingthe val-ve and for supplyingpressure fluid to the inlet passages, and an eXtension on one end of the valve forming a bearing portion for the valve.

' 2i Ina fluid actuatedrock drill, the combination of a cylind'erhaving a piston cham ber and a piston in the piston chamber, an

exhaust port'in the cylinder, a valve chest having a valve chamber, inlet passages lead ing from the valve chest to the piston chamber, 'a valve in the valve chamber having a pair of flanges, annular pressure areas on the flanges, ports in theflan'ges to supply pressure flu-id to the pressure areas for throwing the valve to supply pressure fluid to the inlet passages, an actuaing surface on one end of the valve subjected to compression to assist in throwing the valve in one. direction, and an actuating surface on the other end of the valve of smaller area than the" first said actuating surface and subjected to compression from the piston chamher to assist in throwing the valve in the opposite direction.

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

7 exhaust port in the cylinder, a valve chest 4:. In a fluid actuated rock drill, the'comto the piston chamber, a valve in the valve chamber controlling the inlet passages, said valve having a central cylindrical body with a pair of external flanges thereon, a supply passage for supplying pressure fluid to the valve chamber between the flanges, pressure surfaces on the flanges, ports in the flanges to supply pressure fluid to the pressure surfaces for throwing the valve and for supplying pressure fluid to the inlet passages, and an extension on one end of the valve forming a bearing portion for the valve.

In testimony whereof I have signed this specification.

JOHN G. CURTIS.

bination of a cylinder having a piston oham her and a piston in the piston chamber, an

exhaust port in the cylinder, a valve chest having a valve chamber, front and rear inlet passagesleading from the valve chamber to the piston chamber, a valve in the valve chamber to control the inlet passages and having a pair of flanges, pressure areas on the flanges, a port in one flange to supply pressure fluid to one pressure area and to the front inlet passage, and a port in the other flange of greater area to supply pressure fluid to the other pressure area and to the rear inlet passage.

5. In a fluid actuated rock drill, the combination of a cylinder having a piston chamber and a'piston therein, an exhaust port for the piston chamber controlled by the piston, a valve chest having a valve chamber comprising an enlarged and a small portion, rear and front inlet passages leading from the ends of the valve chamber to the piston chamber, a valve in the valve chamber to control the inlet passages and having a stem operable in the reduced portion of the valve chamber, a pair of flanges on the valve lying in the enlarged portion of the valve chamber, an-

nular pressure areas on the flanges against which pressure fluid acts to throw the valve, an actuating surface on the front end of the valve subjected to compression to assist in throwing the valve rearwardly, an opposed actuating surface on the valve of smaller area than the first said actuating surface'and against which comgpression acts to assist in throwing the valve forwardly, ports in one flange through which pressure fluid flows to the rearward actuating surface and to the front inlet passage, and ports in the other flange of greater area than the first said ports to supply pressure fluid to the forward pressure area and to the rear inlet passage.

6. In a fluid actuated rock drill, the combination of a cylinder having a 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

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