US769373A - Valve-operating mechanism. - Google Patents

Description

No. 769,873. PATENTED SEP' G, 1904.

E. E. ARNOLD.

VALVE OPERATING MECHANISM.

APPLIGATION FILED FEB. 6, 1903. N0. MODEL.

WITNESSES: m Var/ran '%&mu 7 I a v 'nm UNIT-ED. STATES Patented September 6, 1904.

PATENT OFFICE.

EDWIN E. ARNOLD, OF WILKINSBURG, PENNSYLVANIA, AS SIGNOR TO THE WESTINGHOUSE MACHINE COMPANY, A CORPORATION OF PENNSYL- VANIA.

VALVE-OPERATING MECHANISM.

SPECIFICATION forming part of Letters Patent'No. 769,373, dated September 6, 1904. Application filed February 6, 1903. Serial No. 142,237. (No model.) i

To all whom it may concern.-

Be it known that I, EDWIN E. ARNOLD, a citi- Zen of the United States, and a resident of VVilkinsburg, in the county of Allegheny and State of Pennsylvania, have invented a new and use ful Improvement in Valve-Operating Mechanism,of which the following is a specification.

My invention relates to mechanism for operating and controlling exhaust valves of fluid-pressure engines; and it has for its object to provide a simple and eflicient means for this purpose which shall operate'effectively and without danger of injury to the valve or any of the cooperating parts by reason of the different pressures which obtain upon the two sides of the valve when closed.

In the accompanying drawings, Figure 1 is a view, partially in end elevation and partially in section, of a horizontal gas-engine 2o equipped with my invention, the parts not essential to adisclosure of invention being partially broken away or entirely omitted. Fig.- 2 is a view, partially in side elevation and partially in section, of'a portion of the valveoperating mechanism, the view being at right angles to that of Fig. 1.

For convenience and definiteness of description I have illustrated my invention as applied to the exhaust-valve of agas-erigine, but with- 0 out intending to limit its scope or use to engines of any specific type or kind, except'in so far as limitations may be imposed by conditions met in practical service.

The engine 1 here shown is provided with 3 5 a supply-pipe 2, through which an explosive.

fluid is fed to the explosion-chamber, no means vfor regulating and controlling the supply be ing shown, since such means do not pertain to my present invention. The products of combustion are exhausted from a chamber 3 through an exhaust-pipe 4:, the port leading from said chamber to said pipe being opened and closed by means of a puppet-valve 5, the stem 6 of which projects into and through a cylinder 7 and is provided nearits lower end with a piston 8, which closely fits said cylinder. ,Below the piston 8 is a stem extension 9, having adjacent to the piston an enlargement or collar 10 of such diameter as to closely fit the interior of the outlet-tube 11, which is in open communication with the lower end of the cylinder 7 at one end and with the atmosphere at the other. The cylinder 7 is also provided at one side with a small port 12, which is above the piston 8 when the latter is in its lowest position .and which communicates with the atmosphere through a passage 13, having a check-valve 14 and an adjustable stopl5 therefor. The cylinder 7 contains also a piston 16, which has a hollow stem or sleeve 17,

both having a sliding fit upon the stem 6.

tr'atedand described is durable and efiicient;

but it may be replaced by a device having different structural characteristics, if desired, provided the modified structure is adapted to perform the required functions.

The sleeve 17 is provided adjacent to the upper surface of the piston 16 with lugs or bosses 21, to which are pivoted links 22, the upper or free ends of which are in turn pivoted to the arms 23 of a bell-crank lever 24:,

having a pivotal support 25 .on a stationary part of the engine. The outer or free end of the long arm'26 of'this bell-crank lever is connected to the strap 27 of an eccentric 28 by a connecting-rod 29, the eccentric being rigidly mounted upon a shaft 80, which is rotated from the main shaft of the engine by suitable gearing. (Not shown.)

With the parts in the positions indicated in Fig. 1 the valve 5 is obviously closed and will be opened by the rotation of the shaft 30 and the eccentric 28 and the resultant movement of the parts connected thereto. The valve may be opened against the action of a pressure that is superiorto that of the atmosphere and may be held closed at the'proper time,

hereinafter described, against a pressure which may be less than that of the atmosphere. In order to take up the shock due to sudden movement of the parts to unseat the valve when it is of large size, the buffer-spring 18 is provided. This has obviously a limited degree of spring action; but it is sufiicient for the purpose. After this buffer-spring has absorbed the shock of starting the opening movement the valve and its stem will be raised by the movement of the eccentric and the parts connecting its strap with the piston 16, and as the latter is raised it will raise the valve 5, together with the piston 8, which is attached to the lower end of the valve-stem 6. Air will thus be permitted to flow in under the piston 8 through passage 11; but the volume of air between the pistons 8 and 16 will remain constant, with a consequent stationary pressure. When the shaft has rotated a sufficient distance, the valve and its stem will obviously begin a downward movement, and any air which has entered the cylinder below the piston 8 through the tubular passage 11 will flow out until the enlargement or collar 10 engages with the walls of said tube, and this will leave a sufficient amount of air in the cylinder to be compressed and serve as a cushion for the valve. Assuming that this seating of the valve takes place before the shaft has made a complete revolution, the piston 16 may continue to descend without effect on the valve, except that it will compress the air between the two pistons,and thus serve to hold the valve closed, whatever may be the difference in pressure upon the two sides of the valve, and in such manner as to avoid all shocks or injury to the parts and also to avoid the wear and deterioration which would attend the employment of a metallic spring for effecting the same function. During the operation of the pistons 8 and 16 more or less leakage of air from the space between the two pistons may take place, and if such is the ease the normal volume will be restored by admission of the proper amount through the passage 13 and the port 12.

The details of construction may of course be varied as regards form, dimensions, and relative location of parts without changing the mode of operation and result, and I therefore desire it to be understood that all such variations are within the spirit and scope of my invention.

a piston, of a cylinder for said piston, a second piston located in said cylinder and movable upon said stem to open the valve, a butlerspring upon the stem against which the second piston impinges in its valve-opening movement and means for actuating said second piston.

3. In a fluid-pressure engine, the combination with a valve having a stem provided with a buffer-spring and with a piston, of a cylinder for said piston, an independently-movable valve-opening piston having a sleeve extension for engagement with said spring in its valve-opening movement and means for mechanically actuating the independently-movable piston.

4:. In a fluid-pressure engine, the combination with a valve having a stem provided with a piston at or near the end opposite the valve and with a buffer-spring at an intermediate point, of a cylinder for said piston having a side port provided with a cheek-valve, a second piston having a sleeve extension and movable upon said stem against said spring to open the valve-and away from it to close the valve and eccentric and lever mechanism for operating said second piston.

5. In a fluid-pressure engine, the combination with a valve having a stem provided near its outer end with a piston and at an intermediate point with a buffer-spring, of a cylinder having a side port provided with a check-valve and an end port, a valve-opening piston having a sleeve extension adapted to engage the spring on the stem in its valveopening movement, an eccentric and lover and link mechanism for operating said valveopening piston.

6. In a fluid-pressure engine, the combination with a puppet-valve having a stem provided with a piston near the end opposite said valve and with a piston-valve beyond said piston, of a cylinder for said piston having a side port provid ed with a check-valve, a second piston located in said cylinder and movable upon the stem against a yielding buffer projection in the direction of the puppet-valve and means for actuating the second piston.

7. In a fluid-pressure engine, the combination with an exhaust-valve having a stem provided with a piston, of a cylinder for said piston, a second piston located in said cylinder and movable in one direction independently of the first piston, an eccentric and connections between the same and the second piston for positively operating and controlling the latter throughout its range of movement.

In testimony whereof I have hereunto subscribed my name this 27th day of January, 1903.

EDWIN E. ARNOLD.

Witnesses:

H. R. TAYLOR, JAMES B. YOUNG.

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