US769332A - Valve-gear for fluid-pressure engines. - Google Patents

Description

No. 769,332. PATENTED SEPT. 6, 1904.

E'..E.ARNOLD.

VALVE GEAR FOR FLUID PRESSURE ENGINES.

nrmonxon nun 21:3. 6. 1903. NO MODEL.

WITNESSES:

I i "gin/ran KBWHM lowing is a specification.

UNITED STATES Patented September 6, 1904.

P TENT OFFICE.

EDWIN E. ARNOLD, OF WILKINSBURG, PENNSYLVANIA, ASSIGNOR TO THE WESTINGHOUSE MACHINE COMPANY, A CORPORATION OF PENNSYLVANIA.

VALVE-GEAR FOR FLUID-PRESSUREENGINES.

SPECIFICATION forming part of Letters-Patent No.. 769,332, dated September 6,1904.

Application filed February 6, 1903.. Serial No. 142,236. (No model.) I V I To all whom, it 711100; concern:

of VVilkinsburg, in the county of Allegheny.

and State of Pennsylvania, have invented'a new andnsei'ul Improvement in Valve-Gear, for Fluid-Pressure Engines, of which the fol- My invention relates to fluid-pressure engines, and especiallyto valve-operating mechanism therefor.-

The object of my invention is to provide a simple and reliable means for effecting the opening of inlet-valves in accordance with the load upon the engine and the prompt and effective closing of such valves irrespective of such load and also without regard to the degree of pressure in the engine, against which the valve closes, whether the same be greater or less than atmospheric pressure.

My invention is shown as applied to the inlet-valve of a horizontal gas-engine and for convenience will be so described, without intention, however, of limiting the invention to any specific type or kind.

In the accompanying drawings, Figure 1 is a view, partially in side elevation and partially in section, of an engine. provided with a valve-gear embodying my invention, certain parts which have no directloearing uponthe invention being omitted or broken away. Fig. 2 is a view, partiallyin plan and partially in section, of the principal elements of the valve-gear, v e Y As illustrated in the drawings, the engine 1 is supported upon suitable masonry 2 and provided with an inlet-pipe 3 and an exhaustpipe 4, arranged for utilization in the usual manner. The port between the inlet-pipe 3 and the explosion-chamber 5 of the engine is opened and closed at the desired intervals by 7 means of a puppet-valve 5, the opening of said valve being effected by-means of gravity and a coil-spring 6.

The upper end of the valve-stem 7 is pro: vided with a cap 8, within which is located a small coil-spring 9, one end of which bears against the upper end of the cap and the other end of which bears against ablock 10, which is mounted upon the valve-stem and has a limited degree of longitudinal movement thereon. A lateral projection 11 from this block is fitted to movein guides 12, with which the casing 13 forthe valve-stem and the parts mounted thereon is provided. The block 10 is also provided with two rollers 14, with which ton 19, the latter operating in cylinder 20.

Rigidly attached to or formed integral with the cams 15 and lever-arm 17 is a sleeve 21, having a projection 22, with which engages a hook 23, pivotally supported upon a leverarm 24. The outer end of the lever-arm 24 is connected by means of a rod 25 to the strap 26 of an eccentric 27 on the shaft 28, the latter being suitably geared to the main shaft of the engine. (Not shown.)

Rigidly connected to the hook'23 is a knockoif lever 29, which rests upon a sleeve or collar 30, having a cam '31 andan arm 32, the outer end of which is connected to the governor of the engine. (Not shown.) As the hook'and knock-off cam and lever mechanism are similar to those embodied in the ordinary tion withthe governor will be readily-underthe connecting means;

In the positions .of the several parts indicated in Fig. 1 the valve 5 is held in closed position and'the spring 6 compressed by reason of the engagement of the rollers 14 on the block 10 with substantially the. highest points of the operating-surfaces of the cams 15. Assuming that the shaft 28 is rotating, its further movement from the position indicated will serve, through the action of the eccentric 27, the strap 26, and rod 25, to raise the lever. 24, and with it the hook 23 and knock-off lever 29. Since the hook is in engagement with the pro jection 22, which is rigidly connected to the cams 15, the latter will be moved forward be- Corliss valve-gear, their operation in connecend of the rod 18 of a vacuum dash-pot pisstood without illustrationof the governor and neath the rollers 14, and the latter, together with the valve and its stem, will be moved downward by the action of the spring 6, and fluid will be thus admitted to the chamber 5 from the inlet-pipe 3. This action will be continued and maintained within the limits of movement of the parts and the contour of the cam-surfaces until the knock-off lever 29 comes into engagement with the knock-off cam 81, and at this point the hook will be thrown outward to release the projection 22, and since the forward movement of the parts above referred to has also rocked the lever 17 and raised the dash-pot piston 19 thelatter when released by the throwing off of the hook 26 will, on account of the resultant pressure upon its upper surface, due to the vacuum produced in the cylinder, quickly restore the piston to the position indicated in the drawings and by the same movement return the cams, the block 10, the valve 5, and the spring 6 to the positions shown. In order that the valve may now be held shut against any drop in pressure that may occur in the cylinder, I have provided that there be an additional travel of the block 10 on the stem of the valve 5 against the spring 9, thus placing the valve-stem under tension and holding the valve on its seat. In case the dash-pot fails to return the earns 15 with sulficient force to give the additional travel of the block 10 against the spring 9 I have provided a reverse-hook 23 on the previously-described hook 23, which engages with the projection 22 of the cams 15 and positively draws these cams back under the rollers 14 of the block 10 to their original position. The spring 9 behind the block 10 also serves to lessen the shock which would otherwise result from the seating of the valve by acting as a cushion to receive the impact of the movement stated.

Since the shaft 28 is geared to the main shaft of the engine, it will serve to determine the instant when the valve 5 shall begin its opening movement and to regulate the speed of such movement, while the position of the cam 31, which trips the knock-off lever 28, determines the degree of opening movement of the valve and the length of time it remains open in accordance with the load on the engine. The speed of the closing movement of the valve is substantially invariable, since it is dependent upon the vacuum dash-pot 20.

It is conceivable that variations from what is shown as regards form, dimensions, and relative location of parts may be made which deviate considerably from what I have specifically shown and described, and I therefore desire it to be understood that all such variations are within the spirit and scope of my invention provided they do not involve substantial departure from the described mode of operation and result.

I claim as my invention 1. In a valve-gear for fluid-pressure engines, the combination with a valve, a spring for opening the same, a cushioned head for the stem of said valve, and cam, lever and dashpot mechanism acting upon said head in opposition to the spring, of an eccentric, lever-audhook mechanism operated by said eccentric to relieve said spring, and governor-controlled means for disconnecting said levcr-and-hook mechanism from the cam, lever and dash-pot mechanism.

2. In a val ve-gear for fluid-pressu re engines, the combination with a valve and a spring for opening the same, of eccentric, lever-and-cam mechanism for releasing said spring and a dash-pot and lever mechanism actuated in one direction by the eccentric, lever-and-cam mechanism and acting independently in the other direction to close the valve.

3. In a valve-gear for fluid-pressure engines, the combination with a valve and a spring for opening the same, of means for normally holding said spring under compression, means for periodically releasing said spring in accordance with the speed of the engine and means for closing the valve independently of the speed of the engine.

4:. In a valve-gear for fluid-pressure engines, the combination with a valve and a spring for opening the same, of a vacuum dash-pot and motion-transmitting mechanism between the same and the valve-stem whereby the valve is seated, an eccentric and motion-transmitting mechanism whereby the spring is released to open the valve.

5. In a valve-gear for fiuid-pressure engines, the combination with a spring-opened valve and valve-closing mechanism having a cushioned connection with the valve-stem, of valvereleasing mechanism that is regulated in accordance with the load on the engine.

6. In a valve-gear for fluid-pressure engines, the combination with a spring-opened valve and spring-releasing mechanism that is regulated in accordance with the load on the engine, of cushioned valve-closing mechanism that is moved into operating position by the spring-releasing mechanism and then operates independently to close the valve.

7 In a valve-gear for fluid-pressure engines, the combination with a spring-opened valve, a valve-closing cam and a cushioned connection between the same and the valve, of governor-regulated means for moving said cam in its valve-releasing direction and independently-acting means for moving the cam in its valve-closing direction.

8. In a valve-gear for fluid-pressure engines, the combination with a spring-opened valve and power-storing means having a uniform speed of operation for closing the same, of governor-regulated mechanism for simultaneously releasing the valve-spring and storing energy in the valve-closing means and then releasing the latter.

9. In a valve-gear for fluid-pressure engines, the combination with a spring-opened valve gines, the eembinationwith a spring-opened inlet-valve and a fluid-pressure-aetuated means for closing the same, of a governor-regulated IO mechanism for releasing the valve-spring and at the same time storing energy in the valveclosing means and then releasing the latter.

In testimonywhereof I have hereunto subscribed my name this 27th vday of January, 1903. i

EDWIN E. ARNOLD. Witnesses: I

H. R. TAYLOR, JAMES B. YOUNG.

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