US215884A - Improvement in valve-gears for steam-engines - Google Patents

Description

2 Sheets-Sheet 1'.

G. H. GORLISS. Valve-Gear for Steam-Engines.

' No. 215,884. Patented May 27,1879.

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A G. H. GORLISS. Valve-Gear fo r Steam-Engines.

No. 215,884. Patented May 27,1879.

UNITED STATES .e'rnu'r OFFICE.

GEORGE H. GORLISS, OF PROVIDENCE, RHODE ISLAND.

JMPROVEMENT IN VALVE-GEARS FOR STEAM-ENGINES.

Specification forming part of Letters Patent No. 215,884, dated May 27, 1879; application filed February 6, 1879.

To all whom it may concern:

Be it known that I, GEORGE H. OORLISs, of Providence, in the State of Ithode Island, have made certain new and useful Improvements relating to Steam-Engines; and I do hereby declare the following to be a full and anism engages and disengages at each stroke.

I have devised an apparatus for this pur pose in which the opening mechanism is connected with the valve by means of a steel shoulder on a light lever, which is operated by means of a light detaching-rod turning on an adjustable center, a stop (which may be adjustable) carried by said rod causing said lever to turn to release the valve and allow it to be closed. The steel shoulder engages with a steel catch-piece 011 the valve-arm, holding it securely, but offering great facility for liberation by a small movement of the light lever which carries the shoulder. The lever carrying the shoulder turns on the same center as the valve, so that there is no rolling motion of one part upon the other. The detachingmovement is effected with certainty at the proper moment, and without exerting any appreciable disturbing influence on the governor.

The following is a description of what I consider the bestmeans of carrying out the invention.

Figure 1 is an elevation of the general arrangement. 'Fig. 2 is an elevation, partly in section, illustrating the invention. Fig. 3 is a plan. Fig. 4 is a detail perspective view of one of the swivel-guides and part of one of the steel-pointed followers.

Similar letters of reference indicate like parts in all the figures.

A description of the mechanism for operating one valve will suffice for both.

0 is the stem or shaft of a steam-inlet valve of the circular sliding description invented and used by me. (Not represented.) K is an arm rigidly fixed thereon.

K is a rod connected to the arm K, and having at its lower end any suitable device for pulling the arm K in the direction to close the valve on the shaft (J.

K is arocking lever, centered on the same valve-shaft O, and receiving a positive rocking motion through suitable connections. (Not represented.) Y

K is alight lever with steel shoulder K", turning on a pivot, K", carried on the lever K having a spring, K, which urges it toward the shaft 0. The shoulder K on the lever K, at each upward movement of lever K engages with the steel catch-piece K on the arm K and lifting thelatter opens the valve.

By releasing the catch K from the shoulder K at the desired point in the stroke, the point of closing the valve, called the point of cut-off, is determined.

K is a light slotted rod loosely embracing a pin, K, fixed in the upper end of the lever K and pivoted at K to another lever, K the position of which latter is controlled by a governor or other means, as shown in Figs. 1, 2, and 3.

The position of the stop K in the slotted rod K determines the point in the stroke at which its shoulder K becomes disengaged from the catch K on the valve-arm K to allow the latter to drop and close the valve.

The slot in the slotted rod K is of sufficient length to accommodate the extreme throw of the parts in every possible adjustment.

At each oscillation of the rocking lever K the shoulder K engages the catch K on the valve-arm K and lifting it opens the valve; but as soon as the pin K", above mentioned, meets the stop in the slotted rod K formed by the end of the slot in the rod, the further motion of the rocking lever K disen gages the valve-arm K and allows it to drop. Shifting the stop K to the right or left by the action of a governor or other means will delay or hasten the period of such dropping. There is no rolling movement of the shoulder K upon the catch K at any time, and no sliding movement except at the instant of disengagement.

A very slight force of resistance applied at the stop K is sufficient to cause the disengagement of the shoulder K from the catch K; but until such force is applied the parts remain engaged without any tendency to separate.

In Fig. 1, I have represented connections adapted for effecting the regulation by the aid of a governor. The levers K turn on fixed centers, their arms being connected to the steel-pointed followers K K the other ends of which play through the swivel-guides K and rest easily against the cam-shaped surfaces 2' i, which are moved up and down, as required, by a governor I as represented.

It will be understood that the descent of the governor-balls I lowers the cam-surfaces i i, and by allowing the steelpointed followers K K to move to the left under the influence of the coiled spring K (shown in Fig. 3,) or other force, moves the center K to the right, and delays the cut-off by delaying the impact of the pin K with thestop K in rod K and liberates the valve-arm X.

By means of the rod K resting on the pin K of the light lever K, as shown, I obtain a delicatemeans of effecting the detaching movement, and can move the other center, K, forward andbackward, either by the means shown or by other means, to effect the changes in the point of cut-off. I esteem it particularly important, however, in connection with my cams z i, which serve as a medium for communicatingthe changes from the governor, which cams are made the subject of a separate application for patent.

Modifications may be made. ism for both ends of the stroke may be operated by any suitable mechanism controlled by the governor; or I can vary the positions of the stops K by hand adjustment, or any other means.

The rod K, with stop, need not be slotted. The lower half of the slotted part may be removed, and it will still maintain the contact of the upper part with the pin K by gravity.

It will be seen that in Fig. 1 the cam-shaped surfaces are shown as operated by a speed governor, while in Figs. 2 and 3 provision is made for a hand adjustment.

The mechanism herein shown and described for regulating the speed is made the subject of a separate application.

I do not claim, broadly, a valve mechanism in which the valve is opened by a dog or shouldered lever pivoted on a rocking lever turning on the same center as a valve; but

I claim as my invention- The rocking lever K carrying the light leverK, with the shoulder K engaging with the catch-piece K on the valve-arm K the whole moving on a common axis with the valve to be operated, in combination with the stop K carried by the light detaching-rod K turning on the adjustable center K and controlled substantially as herein specified, the whole being arranged, constructed, and operated substantially as herein set forth.

In testimony whereof I have hereunto set. my hand this 1st day of February, 1879, in the presence of two subscribing witnesses.

GEO. H. CORLISS.

Witnesses:

JEssE WALRATH, GEORGE A. Donen.

The mechan-

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