US555738A

US555738A - Operating mechanism for throttle-valves

Info

Publication number: US555738A
Authority: US
Publication date: 1896-03-03
Anticipated expiration: 1913-03-03

Description

(No Model.) 2 Sheets-Sheet 1.

K. RUSHTON. OPERATING MECHANISM FOR THROTTLE VALVES.

No. 555,738. Patnted M5123, 1895.

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I nventor' Wit 7665565 lferuzet/v .Zluskicm M 5 M W (No Modei.) 2 Sheizs-Sheet 2.

K.RUSHTON.; OPERATING MECHANISM FOR THROTTLE VALVES.

No. 555,738. Patented Mar-Q 3, 1896.

AMBREW BGIAH M PHOID-UMQWASMINEWREE.

lJNrE STATES KENNETH RUSIITON, OF PHILADELPHIA, PENNSYLVANIA OPERATING MECHANISM FOR THROTTLE-VALVES.

SPECIFICATION forming part of Letters Patent No. 555,738, dated March 3, 1896.

Application filed July 31, 1895. Serial No. 557,788. (No model.)

To aZZ whom, it may concern.-

Be it known that I, KENNETH RUsH'rON, a citizen of the United States, residing in Philadelphia, Pennsylvania, have invented certain Improvements in Operating Mechanism for 'lhrottle-Valves, of which the following is a specification.

The object of my invention is to so construct lever mechanism for operating throttle-valves under pressure that the leverage exerted will be greater in starting the movement of the valve than in continuing the movement, whereby when the valve is subjected to pressure the power is exerted most advantageously, while when the valve has been partly lifted and the pressure upon the same reduced or equalized the decreased leverage provides for a quicker movement of the valve than in starting to open it.

A further object of my invention is to hold the valve in the closed position by means of the lever mechanism.

In the accompanying drawings, Figure 1 is a view partly in section of the throttle valve illustrating my invention, showing the valve closed. Fig. 2 is a view of the lever mechanism, showing the valve-stem raised part way. Fig. 3 is a view showing the valvestem raised the full height. Figs. 4 and 5 are views illustrating modifications of the invention, which illustrate a rocking motion. Figs. (5 and 7 are views showing changeable fulcrums of the lever, the lever being shown in. mid-position.

In Fig. 1, A represents the ordinary throttle-valve casing, which is adapted to a locomotive and through which the steam passes from the boiler.

B is the valve having two disks Z) Z) adapted to valve-sears a a on the casing, the pressure being external, as shown by arrows, and the excess pressure being downward,owing to the difference in area of the valvedisks b b. Secured to the valve is a \alvestem 13', having a head 13 in which are slots 0 c, and adapted to these slots are pins d d, mounted on one arm of a lever D fulcrumed at 61- the lever D being connected to an opcrating-rod D at d.

Then the valve is in the position shown in Fig. 1, the pin 61 is in the upper'portion of the slot 0 and the pin (1 is in the lower part of the slot 0 and rests against the bottom of the slot, holding the valve closed.

The first movement of the lever D in the direction of its arrow, Fig. 1, will be to elevate the valve-stem I)" and its valve through the medium of the pin (1, being represented by the lines X Y. Consequently with this leverage the valve can be readily lifted off its seat against the pressure; but as soon as the lever reaches the position shown in Fig. 2 the pin (1 has reached the upper end of its slot. Consequently it acts on the valve-rod, the leverage being then that represented by the lines X. Z. Hence the valve is raised quickly with little exertion, as the pressure on the valve is equalized. Thus, while the movement in starting is comparatively slow, said movement is easy, owing to the advantageous leverage, while when the leverage is decreased the force to be overcome is also decreased as the pressure upon the valve is decreased or equalized. IIence rapid movement of the same is possible without undue effort.

Instead of shifting the bearing of the lever upon the valve-stern from one pin to another, as shown in Figs. 1, 2 and 3, I may substitute therefor a modified form of shifting bearing consisting of a curved head B againstwhich the upper portion of the lever D bears, and as the lever moves in the direction of the arrow, Fig. 4, the leverage will be gradually decreased from X Y to X Z as the valve is raised. Consequently instead of an abrupt shifting of the hearing, as in Fig. 1, a gradual shifting of the same and a gradually-increasing movement of the valve will take place.

In Fig. 6 I have shown the lever as provided with a shifting bearing upon its fixed support instead of upon the valve-stem, said bearing being the two pinsff adapted to slots 9 g, and in Fig. 7 I have shown a rocking bearing B of the lever upon the fixed support. Itwill be evident, therefore, that the object of my invention is attained by the shifting bearing of the lever, whether that shifting bearing be the bearing of the lever on the valve-stem or on the fixed support.

I claim as my invention 1. The combination of a throttle valve closed by pressure, with an operating-lever having a shifting bearing, whereby the leverage exerted is greater in starting to open the valve, than after the movement has been started, the valve-rod being connected to the lever, whereby no movement of the valverod, when the valve is closed, is possible without corresponding movement of the lever, substantially as described.

2. The combination of the casing, the valve therefor closed under pressure, its stem, a head on said stem, a pivoted lever having a fixed fulcrum and a movable connection with the head, the first movement of the lever being to raise the valve slowly against the pressure, the movement of the valve being increased owing to the change of leverage, substantially as described.

3. The combination of a throttle valve closed by pressure with an operating-lever having a shifting bearing, whereby the leverage exerted is greater in starting to open the valve, than after the movement has been started, said lever being so coupled to the rod as to hold it in its closed position, sub stantially as described.

4. The combination of the valve-casing, the valve, its stem, the head on the stem, two slots in the head, a lever having a fixed fulcrum and having projections adapted to the slots, each projection having a certain amount of lost motion Within the slots and so arranged that the projection nearest the fulcrum will act first to move the valve off its seat and the second projection will act to open the valve, substantially as described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

KENNETH RUSHTON.

Witnesses:

HENRY HoWsoN, WILL. A. BARR.