US1109807A - Valve-gear for steam-engines. - Google Patents

Description

E. F. WILLIAMS & LE G. SKINNER. VALVE GEAR FOR. STEAM ENGINES.

APPLICATION FILED JULY 21, 1913.

Patented Sept. 8, 1914 UN TED STATES PATENT oFFIoE.

' EDWIN F. WILLIAMS AND LE GnA'ND SKINNER, or ERIE, PENNSYLVANIA, assloNogps TO THE SKINNER ENGINE coMPANY, F ERIE, PENNSYLVANIA, A comonn'rjou' OF PENNSYLVANIA.

VALVE-GEAR r011 STEAM-ENGINES.

Specification 0! Letters Patent.

Patented Sept. 8, 1914;;

Application filed July 21, 1913. Serial No. 780,202.

To all whom it may concern:

lle it known that we, EDWIN F. \Vmmhits and LE GRAND SKINN-En, citizens of the United States, residing at Erie, in the county of Erie and State of Pennsylvania, have invented certain new and useful Improve ments in Valve-Gears for Steaunllngines, of which the following is a-specification,

This invention relates to valvegears for steam engines and is particularly applicable to the exhaust val vesof steam engine cylinders of the 'unitlow type, having a ccn tral exhaust at the middle ofthe cylinder, and auxiliary exhaust passages located between the middle of the cylinder-and the cylinder heads, witlrmechanically operated valves controlling the auxiliary exhaust passages. Although it is preferable, it is not essential that a. central exhaust beused. Then it is used, the opening of the auxil iary exhaust valves may be so timed as to occur after the opening of the central exhaust, permitting'the auxiliary valves to be opened without pressure. ,lVhen the middle exhaust is not used, it isevidentthat the outlet valves will have to be lifted'against whatever pressure exists in the cylinder at the time of release.

In our U. S; Patent'No.;1,033,280 an engine is illustrated having central and auxiliary exhaust ports, and the presentimprovcment relates to the form of the auxiliary valves and the mode of operating and controlling them. In the patent gridiron valves are shown, operated by sliding and rolling cams; in the present case'puppet valves are used, preferably unbalanced, operated by rocking cams, and with means for putting the cams out of operation antomatically by the action of vacuum in the exhaust pipe,'and into operation when vacuum does not exist, as when the'engineis runing condensing and noncondensing, re-' spectively.

In the accompanying drawingsFigure l is a part longitudinal section of the cages and valves, on the line 1-1 of Fig. 2. Fig. '2 is a transverse section on the line 22 of Fig. 1. Fig. 3 is a fragmentary section on the line 3-3 of Fig. 1, showing the vacuum control devices.

Referring specifically to the drawings, T is the cylinder; U the middle exhaust ports;

S the auxiliary exhaust ports, located between the middle ports and the cylinder heads; R theexhaust passage; and P the exhaust pipe leading therefrom.

A is the auxiliary exhaust valve, of thepuppet type, and D its spindle leading through the valve casing B down to an idler cam or lever E which in turn is operated bythe lifter F, which is operated by the rocker arm I and its shaft X to which it is cured. The rocker arm is operated tively by an eccentric on the crank shaft (not shown) or. by attachment-to some equivalent moving part of. the. engine. There is a guide C secured to the valve stem, and above it a coiled spring Q, tending to close the valve. The idler E is fixed to its tubular casing L from which an exhaust pipe V leads to the exhaust'pipe of the envine. The'gear is located in aclosed casing which forms an oil chamber which will be partly filled with oil, making the-gear self oiling.

J is a stutlingbcx to prevent-oil leak along:

the shaft .X and IV is a cap screw which pastshaft N, which has end play, and'is held in its operating position by 'a-spring M in a closes the chamber in which the N opcrates.

H 'is an shaft.

In operation, when the shaft X is rocked, the lifter F comes in contact with the idler E at mid travel, raising it, andby means arm which the rocker of the valve stem, the valve A is-also raised I "and'opencd. Then the motion is reversed the valve follows the movement of'the lifter F downward until it seats, and at the same instant the idler E reaches its rest Y which is-a projection on the inside of the casing,

and the idler E leaves the valve stem D a trifling space, so thatthe idler is free to slide laterally. The foregoing isthe-operation when the engine is operating non .I"

condensing.

In theppesende of a vacuum inthe exhaust pipe, the operation isas follows: As stated, thechamber in -the"' tube L isconnected by the pipe V. to the'exhaust, and

when thereis' sufficient vacuum in the exhaust. the shaft N and the idler E are i drawn sidewise, against the tension of the spring M, until the hub of the idler strikes the face f of the chamber. This movement carries the idler E' outof the path of the lifter F and consequently the exhaust valve A is not lifted, but remains seated; Should I the vacuum break, the spring hi forces the shaft 1 and idier E hook to working posi tion, and the vs The ordinary operation of the mi is on haustports U, which is well known, is such that the auxiliary valves A. wi'li then open without pressure, and in any event will slways close without pressure.

What we claim as new is:

I. In a valve-controlling mechanism for stezmrcngincs, the combination of an exhaust valve, 21 positive gear for operating said val e, means controlled by vacuum in the exhaust pipe for making the gear inoperative, and means for holding said valve closed when the is inoperative.

' 23. In velvecontrolling mechanism for steam-engines, the combination of an exhaust vaive, av spring tending to close said valve, :1, gear operating to open said valve, and means controlled by vacuum in the exhaust pipe for making ti? gear inoperative, whereby the valve will remain clcscd when vacuum exists.

3. In a valve-controlling mechanism for steam-engines, the combination of an exhaust valve, a shiftable rocker, and its shaft acting on said valve to open the same, means controlled by va'cuum in the exhaust pipe to shift the shaft, and rocker to inoperative position when such sufiicient vacuum exists, 'and means to return the shaft and rocker to operative position when the vacuum fails.

4.1m a valve-controlling mechanism for steam-en 'ncs, the combination of an exhaust va ve ofthe puppet type, an operating device bearing under the stem of the valve and acting to lift and open the same, and means controlled by vacuum in the exhaust pipe to move the device to inoperative position.

5. In a valve-controlling mechanism for ,stcamcngincs, the combination of an exhaust valve, a rocker and its shaft acting on said valve to open the same, said shaft being shiftablc endwise to bring the rocker to inoperative position, and a spring pressing against the shaft and tending to hold the same in operative position, said shaft being exposedto vacuum in the exhaust pipes 0peratin' in the presence of suflicient'vacuum, to shift said shaft against the tension of the sprin 6. In a valvecontrolling mechanism for steam-engines, the combination of an exhaust v'zllve, a chamber connected to the exhaust pipe, at rock shaft slidablc lengthwise A will then be c erated.

mosses s it HG exposed at one end to said chamber, a lover acting the valve to when in op rive psition, tending to hoid the in opcrsi. tion.

7. In a valvc-controliing mechanism for stecmcngincs, the combination of the haust valve A, the idler adapted to lift the same, the vacuum chamber L connected to the exhaust pipe, the shifting sliafft N to which the idler is attached, said shaft being exposed at one end in the chamber, whereby it will shift and carry the idler to inoperative position when suflicient vacuum exists in said chum er, a spring tending to sl the shaft in the opposite direction, means to operate the idler,

8. In a valveroni-rolling n'icchcnisic for steam-engines, the combination of an haust valve, a rock shaft and liitcr thereon, a shiftsblc idler lornted b won the iiitcr and valve to operate the luucr, means corn trolled by vacuum in tile exhaust pipe to shift the idler from its position, and means tending to return the idler to said posi .ion.

9, In a valve-controlling mechanism for steam-engines, the combinaiion of an exhuust valve, a rocking cum operating on said valve, means controlled by vacuum in the exhaust pipe for shifting the cum to inoperative position, and means for :hifting the cam to operative 'Josition when the vacuum ceases to exist.

10. In a valve-controlling: mechanism for steam-engines, the comoiuution of an ex haust valve of the puppet type hnvinga projecting stem, a rocking cam adapted to bear against said stem to operate the valve, means controlled by vacuum in the exhaust pipe for'shifting'the cam to inoperative position, and means for shifting the to operative position when the vacuum to exist.

11. In a valve-controlling meclmnism for steam-engines, the combination of an exhaust valve, 21 positive gear for operating said valve, means for making the gear in operative when vacuum occurs in the oxhaust pipe and operate when said vacuum is broken, and means for hohling the valve closed when the gear is inoperative.

In testimony whereof, we do nlli); our sipg natures in presence of two witnesses,

EDWIN F. WILLIAMS. LE GRAND SKI llll.

and

)DULON.

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