US43142A - Improvement in valves for steam-engines - Google Patents

Description

Wars:

D. B. TRAVIS. VALVE EoE TEAM ENGINES.

Patented June 14. 1864.

UNITED STATES PATENT OFFICE.

o. BTRAVIS, or LA caossn, WISCONSIN.

8i IMPROVEMENT m VALVES Foe. STEAM-ENGINES- Specification forming part of Letters Patent No. 43,11), :latcil June 1-1, 1864.

To all whom it may concern: I

Be it known that I, DAVID B. TRAVIS, of

5 La Grosse, in the county of La Orosse and State of Wisconsin, have invented a new and useful Improvement in Steam-Engines; and I engine illustrating my improvement. Fig. 2'

is a plan of the valve-seats and horizontal section of the valves. Fig. 3 is a-simila-r view to Fig. 2, but showing the parts in different positions. Fig. 4 is a plan of the bottom of the valve-chest.

Similarletters ofreferenceindieatclike parts.

This "invention consists in a novel system of movable valve-seats and stationary and movable ports in combination-with slide-valves in a steam-engine, whereby the engine is enabled to be reversed and stopped very quickly and easily.

The invention is applied in connection with two slide-valves, A A, one for eflecting the induction and eduction of the steam to and from oneend, and the other for effecting the induction and eduction to and from the other end, of the cylinder, the said "alves' being inclosed within a valvechest, B, to which the steam is admittc d, and the two being connected by a rod, 0, and worked by a rod or [width of the chest, and arranged on one side of a line drawn longitudinallyand centrally upon the face a, and the two at each end communicate with a single steam way, (7, which communicates with their'respective end of the cylinder. The two ports 0, which are forthe exhaust, are arranged between the same parallel lines drawn lengthwise upon the seat a,

and on the opposite side of the central longitudinal line to that on which b b are arranged, I

and each is arranged opposite the middle of the space between its respective portsb b, and the two communicate, as shown in dotted lines in Figs. 1, 2, and .4, \v'ith a. common exhaustchamber, 0. j

F F are the movable val\ e-seats, twoin number, one for each valve. Each. consists of a.

flat plate of iron faced on'bot' sides and fitted to the face a, which maybe called the permanentseat, and titted to work frecl y between the sides of the'valve chest or between suitabie guides provided therein, and each is made with astem,f, to enable it to be connected with one ofthe two arms g g ofa shalt, G, which is arranged perpendicular to the seat a, and fitted to a bearing in the center of the said seat, and toa striding-box, h, in the center of the cover B of the valve chest. The-said stems are arranged on' opposite sides of the said shaft, and the said arms set in opposite directions, so that "byturning the said shaft by m'eans of 'a. lever, H, or its equivalent, secured to it outside of the valve-chest, the two seats may be moved in opposite directions both toward or both from the ends of the chest. A. pinion may be substituted for the arms 9 g to work in toothed racks on the valve-stems. In each of the movable seats there are three ports, 01 t" j, passing through it. The ports z i are so arranged that they occupy the same space in the width of the valve-chest as the ports b b but they are about one-third narrower in the direction of the length of the chest, and are set nearer together, the difference being a. little more than the width of 01 e of the portsii, so that when the movable seats are close up to the ends of the valvechest, as shown in Fig. 3, and the outer edges of the outer ports, -i i, are in the same vertical lines with the outer edges of the outer ports, b b, the inner ports, b b,are effectually closed by the movable seats, and when thcsa'id seats are brought to the reverse positions shown in Fig. I, and in black outline in Fig. 2-that is tosay-with the inner edges of thein ner ports,

ii, in the same vertical lines with the inner ports, b b-the ports I) b are etfectually closed by the valve-seats. The exhaustports j in the movable seats are arranged, like thoseot 0, in thepermanent seat-that is to say, on the op posite side of the center of the valve and midwaybetween the two portsi i; but the exhaustports 0 in the permanent scat are made so Fir. 2.

right-hand end of the chest in Fig. 1, each in port j,and that when the said seatsare in the I by the movements of the valves toward their engine is produceddcpends upon the position much wider than those of j in the movable seats that there is always free communication between the said ports) and c, whatever he the positions of the movable seats. Stops k k are secured in the-permanent seat a to prevent the movable seats approaching each other nearer than is necessary-to bring the 'ports j to the positionsdescribed with reference to '1" he valves A A are of such area that their exhaust-cavitiesl will cover-the whole three of their respective'portst' 1'' 'and the said valves are so set thatwhen the movable seats are in the positionreprescnted in Fig. 1 and black outline in Fig. 2 the said valves will 11' cover and admit steam to the two inner 1) its, 6 i, as will be seen by reference to the itsturn, and always bring the other one into communication with its respective exhaustposition shown in Fig. 3, the said valves will client the induction ot'steam to and from the two outer portsg i i. In the last-mentioned I position of the movable seats the opening of the ports to the steam is effected by themove- 111 *nt of the valves away from their respective e ids of the steam-chest, and in the first-mentioned position of the said seats it is efi'ected respective ends 'ofthe chest, and hence the direction in which the rotary, motion of the of the valves. It will therefore-be understood that (it is only necessary to shift the herein. set forth.

ports b b in the permanent seat a, any steam that might be in the cylinder at the time of thevalves brought to that position will escape through the exhaust-ports, leaving the piston free.

"In setting'the valves with 4 lead, whatever lead is given for running the engine in onedirection is also given in running in the opposite direction, without changing from one wrist to another of the valve rock-shaft.

I do not claim, broadly, the employment of movable valve-seats for eflecting'thc reversal of steam-engines; but- What I claim as my invention,'amldesire to secure by Letters Patent, is

The combination, with two slide-valves, A A,

of two movable three-ported valve-seats, F F, and a system of six ports in the permanent seat, the whole. constructed, arranged, and operating substantially as. and for the purpose a DAVID B. TRAVIS. Witnesses; 4 g

' HARVEY E. HUBBARD,

, A. T. CLINTON.

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