US281812A

US281812A - Cut-off valve

Info

Publication number: US281812A
Authority: US
Publication date: 1883-07-24
Anticipated expiration: 1900-07-24

Description

(No Model)" N. W. WILLIAMES. CUT-OFF VALVE.

a ented J u1y 24, 1883.

N. PETERS. Pnmum her. immune u. c.

UNITED STATES PATENT OFFICE.

NAPOLEON V. \VILLIAMES, OFlFHILADELPI-IIA, PENNSYLVANIA.

CUT-OFF VALVE.

SPECIFICATION forming part Of Letters Patent N0. 281,812, dated July 24, 1833.

Application filed April 27, 1883. (No model.)

To aZZ whom it may concern.-

Be it known that I, NAPOLEON W. WILL- IAMES, of the city of Philadelphia, county of Philadelphia, and State of Pennsylvania, have invented an Improvement in Automatic Cut- Off Valves for Steam-Engines, of which the following is a specification. 7

My invention has reference to cut-off valves and valve-gear for steam-engines; and it consists in supporting the cut-off valves upon the main slide-valve and carrying them thereby in one direction, and synchronously with the said slide-valve, the latter being reciprocated by asingle eccentric or cam, the said cutoff valves being moved at or about at right angles to the movement of said slide-valve by means of levers pivoted to the slide-valve, and having their free ends working in slots of limited length in the ends of arms which are moved automatically by the governor to control the location of said slots, and consequently the points of cutoff, from zero to one half-stroke or more, and in many details of construction, all of which is fully set forth in the following specification, and shown in the accompanying drawings, which form part thereof.

The object of my invention is to provide a simple, cheap, and eflioient automatic cut-off for valves of steam-engines.

In the drawings, Figure 1 is an elevation of my improved automatic variable cutoffivalve mechanism for steam-engines with the steamchest broken away. Fig. 2 isa section of same on line at m. Fig. 3 is an elevation of a steamengine with my valve mechanism attached thereto. Fig. 4 is a cross-section of thevalvc on line 1 7 and Fig. 5 is an elevation of a modified form of apparatus.

A is the steamchest. B is the cylinder. 0 is the face or valve-seat. D are the steamports; and E are the exhaustports. The construction shown is a twin valve; but while I prefer to make it this, it is selfevident that I may use the ordinary Dvalve, the only difference in construction being that the valve would only contain one exhaust-cavity and there would only be one exhaust-port. I

F F are the two valve-heads, and are con nected by bars F, the whole being reciprocated by a single valve-rod, F and eccentric or cam F" on the engineshaft T; or it may be reciprocated by any other of the numerous well-known valve mechanisms. Each of these heads F has an exhaust cavity, G, and a steam -port, which is made of a transverse groove, H, extending almost across the face of the valve, and into which the steamis admitted by slots or ports J, opening through the valveheads. \Vorking in grooves K across said valve-heads, and immediately above the ports J are the cut-off valves K, which are provided with apertures or ports L, corresponding in size and distance apart with the ports J. These cut-oil valves K are reciprocated across the slide or main valve, while being rcciprocated by said main valve during its movements, by means of levers M, pivoted to said main valve at m, and connecting with said outoff valves by means of pins 70. The other or free ends of levers M are provided with pins N, which Work in slots 0 on the ends of arms 0, pivoted to and radiating from a dashpot plunger, 1?, arranged to have vertical movement in a cylinder, P, by means of rod Q, which is raised or lowered in accordance with the variations in steanrpressure, and also the speed of the engine. In the position shown in Fig. 1 the steam is cut off from both ends of the cylinder, as is also the exhaust; but upon moving the valve to the left the exhaust-steam would escape from the right-hand end, and steam would be admitted to theright-hand end of the cylinder. The pin N, striking the end of slot 0, suddenly moves the cut-off valve and closes the ports J, and, as set, cutting off the steam at half stroke. Upon reversing the movement of the slide or main valve the reverse operation takes place, alternately admitting steam and cutting off at each end of the cylinder. Now, it is evident that if the dash -pot plunger 1 be raised, the arms 0 assume more of a horizontal position, moving the slots 0 farther apart, and this action necessarily varies the time of reciprocating the valves K, and consequently the cut-off, and when they are horizontal there is no admission of steam at all. The rod Q is raised by either of two mechanisms, or both combined.

R is a cylinder, open on the top, in which a piston, Q, secured to rod Q works, steam being admitted to the under side 7 of said piston, either from the valve-chest or steam'pipe R, or both. N ow, if the boiler-pressure vary, the piston moves up or down, varying the cut-off of the engine, and thereby overcoming any variation of speed due to this cause. The rod Q extends up, as at Q, being forked, if desired, and is secured to a cross-head, Q", which is raised or lowered by the usual centrifugal or ball governor upon increase or decrease in speed, due to varying the amount of work put upon the engine. v

The two exhaust-ports E may be connected by one exhaust-pipe, E.

It is evident that in place of levers M racks and pinions or segments of gear may be used, and in place of making two distinct levers or segments a single one may be used, as shown in Fig. 5, inwhich M represents the segmental gear; and in place of putting the slots 0 in the arms 0 or stationary part, they may be made in the lovers M or segment M, and the pins N put in the said arms or dash-pot plunger P, as shown also in Fig. 5, in which N is the slot, and N the pin. By moving the pin up in slot N the time of cut off is varied, as set forth above. The operation of the devices is similar. Again, it is'evident that in place of using straight cut-off valves they might be made integral with the segment or arms 5 but this is not desirable.

By the construction of my improved valve the main valve remains fixed as to its lead, lap, &c.; but the lead and lap of the cut-off valves are varied 'by the governor to suit the different loads that may be thrown upon the engine at different times.

Having now described my invention, what I claim as new, and desire to secure by Letters Patent, isp 1. A main slide-valve, in combination with two independentlyacting cut-off valves supported and carried thereon, and arranged to be reciprocated at right angles to the movement of said main valve, substantially as and for the purpose specified.

2. A main slide-valve, in combination with two independently-acting cut-off valves supported and carried by said main slide-valve, in combination with means to reciprocate said main valve, and mechanism to separately reciprocate said cut-off valves at right angles to the line of movement of the main valve, substantially as and for the purpose specified.

3. A main slide-valve, in combination with two independently-aeting cut-off valves supported and carried by said main slide-valve, in combination with a single eccentric or cam to reciprocate said main valve, a governor, and mechanism controlled by the governor to separately reciprocate said cut-off valves at right angles to the line of movement of the main valve and vary their points of cut-off, substantially as and for the purpose specified.

4. A main slide-valve, in combination with two independently-acting cutoff valves supported and carried by said main slide-valve, a rod, mechanism, substantially as described, and located wholly within the valve chest, connecting said rod with said cut-off valves, and automatic mechanism controlled by the speed of the engine to move said rod and vary the point of cut-oil, substantially as andfor the purpose specified.

5. A main slidevalve, in combination with cut-off valves supported and carried by said main slide-valve, a rod, mechanism, substantially as described, connecting said rod with said cut-off valves, and automatic mechanism controlled by the varying pressure of the steam to move said rod and vary the point of cut-off, substantially as and for the purpose specified.

6. A main slide-valve, in combination with cut-off valves supported and carried by said main slide-valve, a rod, mechanism, substantially as described, connecting said rod with said cut-off valves, and automatic mechanism controlled by the speed of the engine, and varying steam-pressure to move said rod and vary the point of cut-off, substantially as and for the purpose specified.

7. The combination of main slide-valve and cut-off valves carried thereby, with levers M, arms 0, having slots 0, rod Q, a governor to move said rod, and means to reciprocate said main slide-valve, substantially as and for the purpose specified.

8. The combination of main slide-valve and cut-off valves carried thereby, with levers M, arms 0, having slots 0, dash-pot P, plunger P, rod Q, a governor to move said rod, and means to reciprocate said main slide-valve, substantially as and for the purpose specified.

9. The combination of main slide-valve and cut-off valves carried thereby, with levers M, arms 0, having slots 0, rod Q, a governor to move said rod, piston Q, cylinder R, and means to reciprocate said main slide-valve, substantially as and for the purpose specified. 10. A main slide valve in combination, and a single eccentric or cam to reciprocate it, with cut-off valves carried by said slidevalve, and means, substantially as described, for reciprocating them at right angles to each other, said means being located wholly within the valve-chest, substantially as and for the purpose specified.

In testimony of which invention I hereunto set my hand.

NAPOLEON XV. \VILLIAMES.

iVitnesses:

It. M. HUNTER, R. S. CHILD, Jr.

IOCi

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