US1813773A - Valve for rock drills - Google Patents

Description

July 7, 1931. w. A. SMITH. JR I 1,813,773

VALVE FOR ROCK DRILLS Filed Aug. 14, 1928 J 1' Z. "fd f j F12. -1. B A E 0 IN VEN TOR.

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H15 ATTORNEY.

Patented July 7, 1931 iii; STATES WILLIAM: A. SMITH, JR., F PHILLIPSIBURG, NEW JERSEY, ASSIGNOR TO INGERSOLL- I BAND COMPANY, OF JERSEY CITY, NEW JERSEY, A CORPORATION OF NEXV JERSEY VALVE FOR ROCK DRILLS Application filed August 14, 1928. Serial No. 299,492.

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

The objects of the invention are to obtain p a durable and light weight valve capable of a rapid and positive action for distributing the pressure fluid to the ends of the cylinder.

.Other objects will be in part obvious and in part pointed out hereinafter, and to all of these ends the invention consists of the combination of elements, features of construction and arrangement of parts substantially as hereinafter described and claimed and illustrated in the accompanying drawings, in which Figure 1 is a longitudinal sectional elevation of a portion of a rock drill showing the valve in position for admitting pressure fluid into the rearward end of the cylinder,

and

o an extension E of the piston B.

The rearward end of the cylinder A is suitably recessed to receive a back cylinder washer F which acts as a closure for the rearward end of the cylinder and in this instance 3 also acts as a seat for a back head G which may be secured to the cylinder by means of suitable side rods H, only a portion of one of which is shown. I

-The rock drill is provided with a valve chest J disposed in this instance on the side of the cylinder A and having a bore K to form a valve chamber. In the rearward end of the valve chest J is a throttle valve chamber L in which is disposed a throttle valve 0 whereby the admission of pressure fluid from a suitable source of supply to the bore K is controlled. For this purpose the throttle valve O is provided with a lever P.

The throttle valve illustrated has a central chamber Q, which may be constantly exposed the valve chest leading to the end of the v bore K.

Disposed in the innermost end of the bore K is a bushing T which may be secured in the bore K in any suitable manner and has a. passage U in constant communication with the passage S in the valve chest J. In the opposite or open end V of the valve chest J is a somewhat similar bushing W which forms a closure for the open end of the bore K. The bushing W has an integral flange X which abuts the end of the valve chest J and through which may extend securing means such as bolts Y whereby the bushing W is secured to the valve chest J.

v The bushings T and W are provided with suitable bores Z and b respectively which form reduced portions of the valve chamber. The bushings T and W in this instance are suitably spaced to form an intermediate enlarged portion 0 of the valve chamber.

The distribution of pressure fluid to the ends of the cylinder is effected by a distributing valve d having a longitudinal bore 6 extending entirely therethrough. The bore c is constantly exposed to live pressure fluid which flows from the throttle valve 0 into the distributing valve d through the passages S and U and the port R. The valve 0? is provided with a pair of flanges f and g which are slidably disposed in the enlarged portion 0 of the valve chamber.

Leading from the rearward end of the reduced portion Z to the corresponding end of the cylinder A is an inlet passage 72, through which pressure fluid may flow for impelling the piston B in a forwardly direction. Similarly at the front end of the reduced portion Z-is an inlet passage 7' which leads to the front end of the cylinder. Portions of the passagesh and j in this instance serve both as inlet and exhaust passages and in this instance exhaust passages 70 and 0 lead from the passages h and respectively to the enlarged portion 0 of the valve chamber. The passages 70 and 0 are so disposed that they may be covered by the flanges f and g of the valve for controlling the exhaust of pressure fluid from the ends of the cylinder into the intermediate portion 0 of the valve chamber from whence such fluid may escape to the atmosphere through an exhaust port p in the valve chest, said exhaust port p being centrally located in the valve chamber.

The outermost ends g and r of the flange and g respectively constitute actuating surfaces against which pressure fluid may act for actuating the valve. Such pressure fluid in this instance is conveyed from the cylinder through kicker passages s and t. The kicker passages s and t are crossed in this instance, the passage 8 leading from a point forwardly of the inlet passage h to the front end of the enlarged portion 0 of the valve chamber, and the passage t leading from a point rearwardly of the inlet passage 7' to the rearward end of the enlarged portion 0 of the valve chamber. Vents a formed in the valve chest near the ends of the enlarged portion 0 afford passages for the escape of a portion of the pressure fluid used to actuate the valve and are controlled by the flanges f and g.

In the construction shown the ends of the valve cl constitute holding surfaces. Accordingly a holding surface 1) is formed on the rearward end of the valve and is adapted to cooperate or seat against a surface w in the bushing T for cutting off the supply of pressure fluid to the rearward end of the cylinder. In like manner the front end of the valve is provided with a holding surface 06 against which pressure fluid may act for holding the valve (Z in a rearwardly position and said holding surface w is adapted to seat against a surface y in the bushing V to cut off the supply of pressure fluid to the front end of the cylinder.

lhe operation of the device is as follows: With the valve (5 and the piston B in the positions shown in Figure 1, pressure fluid entering the bore 6 of the valve will flow over the rearward end of the valve and act against the holding surface i) to hold the valve (Z forwardly and thence flows through the inlet passage 7t into the rearward end of the cylinder to actuate the piston B forwardly against the implement intended to be actuated. In this position of the valve the flange f will cover the outlet opening of the exhaust passage is so that there will he no loss of pressure fluid through this passage.

As the piston B proceeds forwardly the kicker passage 8 will be uncovered thereby and pressure fluid will then flow through said kicker passage into the front end of the enlarged portion 0. This pressure fluid will act against the actuating surface 1 of the flange g and will throw the valve (Z rearwardly to the position illustrated in Figure 2 at about the time that the piston B delivers its blow to the working implement.

With the valve thus reversed pressure fluid will flow over the front end of the holding surface 00 through the passage into the front end of the cylinder to actuate the piston B rearwardly. During this admission of pressure fluid to the front end of the cylinder the pressure fluid will act against the holding surface as to hold the valve rearwardly.

After the piston B overruns the kicker passage If pressure fluid will flow through said kicker passage into the rearward end of the enlarged portion 0 to act against the actuating surface for throwing the valve (Z to its initial position. \Vhen this movement of the valve cl occurs the exhaust passage 0 will be uncovered by the flange g and the pressure fluid will escape from the front end of the cylinder through the inlet passage and the exhaust passage 0 into the enlarged portion 0 of the valve chamber. From this point the pressure fluid may readily escape to the atmosphere through the exhaust port p. The portion of the pressure fluid utilized for actuating the valve may of course return to the cylinder to be exhausted through the passages j and 0 along with the pressure fluid utilized for actuating the piston. However, after the vent u is uncovered pressure fluid ill also escape to the atmosphere through said vent.

I claim:

in a fluid actuated rock drill, the combination of a cylinder and piston, a valve chest having a valve chamber comprising an enlarged intermediate portion and reduced end portions, anexhaust port leading from the intermediate portion to the atmosphere, inlet passages leading from the reduced end portions to the ends of the cylinder, exhaust passages leading from the inlet passages at the ends of the cylinder to the enlarged intermediate portion of the valve chamber, a hollow valve in the valve chamber constantly exposed interiorly to live pressure fluid and extending slida-bly with its ends into the re duced portions of the valve chamber, a pair of flanges on the valve slidable in the enlarged portion to control the outlet openings of the exhaust passages, actuating surfaces on the outer ends of the flanges, crossed kicker passages leading from the intermediate portion of the cylinder to the ends of the enlarged portion for conveying pressure fluid to act against the actuating surfaces for actuating the valve, vent ports in the valve chest spaced from the ends of the enlarged portion and adapted to be controlled by the flanges, and holding surfaces on the ends of the valve exposed to pressure fluid flowing to the cylinder for holding the valve in thrown position.

In testimony whereof I have signed this specification.

WILLIAM A. SMITH, JR.

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