US2546844A - Fluid distributing valve mechanism - Google Patents

Description

March 27, 1951 ALLEN 2,546,844

FLUID DISTRIBUTING VALVE MECHANISM Filed May 25, 1946 INVENTOR Roy OHM en.

BY a

H \S ATTORNEY.

Patented Mar. 27, 1951 FLUID DISTRIBUTING VALVE MECHANISM "Roy 0. Allen, Athens, Pa.,-assignor to Ingersoll- Rand Company,.N e.w York, N. Y.., acorporation of New Jersey Application May- 25, 1946; Serial No; 672,275

. 3 Claims: (01. 251 -118) This invention relates to valve mechanisms, and more partciularly to a fluid distributing valve mechanism for fluid actuated tools of the percussive type.

One object of the invention isto assure the retention of the valve parts in the correct assembled relationship with respect to each other.

Other objects will be in part obvious and in part pointed out hereinafter. In the drawings accompanying this specification and in which similar reference numerals refer to similar parts,

Figure 1 is an elevation, partly in section, of a fluid actuated percussive tool equipped with a distributing valve mechanism constructed in ac- I cordance with the practice of the invention, Figure 21s a transverse view taken through Figure 1 on the line 2-2, T

Figure 3 is a perspective view of the distributing valve,

Figure 4 is a similar view of a valve chest part, and

Figure 5- is a transverse view taken through Figure 1 on the line 55.

Referring more particularly to the drawings, the percussive tool of which only so much is shown as will serve to illustrate a practical application of the invention, and desigated in its entirety by 2|], comprises a cylinder 2| having a "piston chamber 22 to accommodate a reciprocato'ry hammer piston 23. The front end of the piston chamber is closed by a head 24 thathas a bore'2 5 to receive slidably the stem 26 of the piston 23, and intermediate the ends of the piston chamber 22 is a free exhaust port 21 that is conrtiollediby the piston 23- In the rearward end of the cylinder. is anenlarged bore 28 to receive-the distributing valve mechanishi'fii which is held irf "position by a back head 3e constituting the rearmost casing par-tot the percussive-tool. The valve mechanism 29 omprises a pair of plates 3| and 32 that constitute a valve chest, and in the member 3| are passages 33 to convey pressure 'fluid from a supply chamber 34 in-the' back head into a valve chamber 35 in the member 3|. Such pressure fiuidis conveyed to the supply chamber by a supply passage 36 in the back head controlled by a throttle valve '31. The pressure fluid passes from the -valve chamber 35 to the rearward end of the piston chamber 22 through a passage 38 in the member 32, and pressure fluid is conveyed to the front end of the piston chamber by a passage 39 in the member 32 and the wall of the cylinder 2|.

2 The valve 48 controlling the distribution of pressure fluid from the valve chamber to the ends Of the piston chamber is of the oscillatory plate type. It is in the form of a disk and tapered uniformly on its opposite sides from the median line, as is customary, and one of the apices thus developed serves as a fulcrum 4| upon which the valve will pivot on a seating surface 42 on the member 32 for controlling the passages 38 and 39. The thickness of the median portion of the valve is slightly smaller than the height of the valve chamber so that the valve may oscillate freely upon the seating surface 42 Without hindrance by the opposed surface of the member 3|.

In order to assure the efiicient operation of the tool the diameter of the valve is, moreover, so proportioned with respect to the diameter of the valve chamber that the spaces or flow areas 43 between the edge of the valve and the wall of the valve chamber and through which the pressure fiuid flows to the inlet passages are sufficiently restricted to assure a slightly lower pressure beneath a raised end of the valve than line pressure to condition the valve for causing an immediate tilting thereof at the instant the pisto starts to uncover the exhaust port 21.

It is essential that the spaces 43 be at all times of substantially constant area in order to avoid an erratic action of the tool and the valve must, therefore, be restrained against movement laterally of the side wall of the valve chamber. To assure this result the member 32 is. provided,

at the central portion of the-seating surface 42,

with a stem 44 that may be integral with the .member 32 or suitably affixed thereto and extends through an aperture .45 in the central portion of the valve 40.. The aperture 45 isof oblong shape :and its; larger transverse dimension is-only sufficiently larger than that of theist'emzM .to-permit of free rocking movement of the valve? The ends 460i the aperture 45'are rounded to conform with the curved surfaces 4! of the stem and are joined by fiatted surfaces 48 that 00- ,operate with similar surfaces 45 onthe stem M to prevent rotative movement of the valve within the valve chamber. The surfaces 48 have sliding fits upon the surfaces 49 so that the valve will also be restrained against movement in the plane of the fulcrum 4|.

To the end that the member 3| may be accurately positioned and retained thus with respect to the peripheral surface of the valve so that the spaces will be of equal areas the stem 44 is formed of a length to extend into an aperture 50 in the member 3|. The aperture 50 may, as illustrated,

position preparatory to the cycleof 1 operation.

be of cylindrical shape but has a snug fit on the curved sides 41 of the stem to maintain the member 3| in the correct position with respect to the valve and the member 32.

In practice it has been found that, owing to the use of only one pin or stem for retaining the valve parts in the correct assembled positions with respect to each other, the flow areas over the ends of the valve necessary for anefiicient operation of the tool may be precisely established and maintained thus throughout the life of the percussive tool.

In the operation of the device and with the valves 37 and 4B in the positions shown in Figure 1 of the drawings, pressure fluid flows through the supply passage 36, the supply chamber 36 and through the passages 33 into the valve-chamber 35. From there the fluid passes through the flow the valve to rock from side to side for controlling the passages in said one member, a stationary stem on one member extending into the aperture and being of only sufficiently smaller diameter than the aperture to permit of rocking movement of the valve about the stem, and means on the valve and on the stem cooperating with each other to prevent rotational movement of the valve within the valve chamber.

2. In a fluid distributing valve mechanism, a valve chest having a valve chamber and comprising a pair of members each having pressure fluid conveying passages opening into the valve chamber and one member having an aperture, an oscillatory plate'valve in the valve chamber to control the flow of pressure fluid through the passages and having an aperture extending axially area 43 at the raised left-hand wing of thevalve I 49 into the forward end of the valve chamber,

thence through the inlet passage 39 into'the front end of the piston chamber'22 to drive the piston '23 rearwardly.

When the piston approaches the rearward end of the piston chamber, during this movement, it

ward surface of the seated wing of the valve through the inlet passage 38, will then tilt the valve M1 to cover the inlet passage 33 and uncover the inlet passage 38.

In the new position of the valve pressure fluid flows from the valve chamber through the flow area 43 at the right-hand end of the valve and through the passage 38 into the rearward end of the piston chamber and drives the piston 23 forwardly on its working stroke. During the intermediate portion of this stroke the piston 23 covers the exhaust port 21 but will uncover it immediately prior to the instant of impact against the implement which the piston is intended to actuate. The fluid will then exhaust from the rearward end of the piston chamber through the exhaust port 21 to the atmosphere,

.and at the same time the pressure fluid acting against the rearward surface of the raised wing of the valve 49 and the air compressed by the piston in the front end of the piston chamber acting against the forward surface of the seated wing of the valve will tilt the valve to its initial I beginningof a new Iclaimfln v I 1. Ina fluid distributing valve mechanism, a

valve chest having a valve chamber and comprising a plurality of members each having pressure fluid conveying passages opening into the valve chamber, an oscillatory plate valve in the valve chamber to control the passages in one member and having an aperture extending axially therethrough, 'a fulcrum at the median line of the valve seating upon one of the members'to enable therethrough,afulcrum at the median line of the valve seating upon one of the members to enable the valve to rock from side to side for controlling the passages in said one member,--'and a stem onone member extending into both apertures to hold the valve in correctly spaced relation with the peripheral wall of the valve cham- .ber and to hold the members in axial alignment with each other, said stein being of only suff ciently smaller diameter than the aperture to permit of rocking movement of the valve abou the stem. 4

3. In a fluid distributing valve mechanism, a valve chest having a valve chamber and comprising a pair of members each having pressure fluid conveying passages opening into the valve chamber and one member having an aperture; in the central portion thereof, an oscillatory plate valve in the valve chamber to control the passages in one member and having an aperture extending axially therethrough, a fulorum at the med-ian lineof .thevalve seating upon one of the members to enable the valve to rock from side to side-for controllin the passages in said one member, a stationary stem on one member extending into both apertures to hold the valve in correctly spaced relation with the peripheral wall of the .valve chamber and to hold the members in axial alignment with each other, said stem being of only sufficiently smaller diameter than the aperture to permit of rocking movement of the valve about the stem, and flatted surfaces in the aper ture of the valve and on the stem to cooperate with each other for holding the valve against rotational movement within the valve chamber.

REFERENCES CITED 7 The following references are of recordj'in the file of "this patent? 'Unrrsn ,s'rffrEs PATENTS. i

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