US94973A - Improvement in steam-engine valves - Google Patents

Description

. ani-fw sam @than @tilting ELTING POST, or BOSTON, MASSACHUSETTS.

Letters Patent No. 94,973, dated September 21, 1869.

AnvrPacman/mira' 1N STEAM-ENGINE vALvns.

The Schedule referred to in these Letters lPatent and making part 0f the Same.

To `all personsV to whom these presents may come:

Be it known that I, ELTING POST, of Boston, ofthe county of Su`olk,and State of Massachusetts, have invented a new. and useful Improvement in-` Steam- Engines; and do hereby declare the same to be fully described in the followingspecitication, and represented in the accompanying drawing, which denotes a vertical and longitudinal-,section of a steam-engine cylinder and piston,` the steam-chest and valve, and

- the passages thereof, as provided with my invention.

G is the valve-case, which isa' hollow'eylinder, pro'Y videdwith aninduct, a, arranged in the middle of its top.

The valveis shown at D, it being cylindrical, and provided with two chambers, ,b c, which are arrangedwithin4 it, and on opposite sides of a channel, d, that extends' around and within it atjts middle. i

There are two openings or ports leading out of the bottom of. each of the chambers b c, they being arranged as shown at e f e f'.

Furthermore, the valve-stem g has two shoulders, h i, arranged on itin manner as represented, there being extended between them an arm, k, projecting upward from the piston-rod Z.

The passages for leading steam to the opposite ends of the cylinder are exhibited at m and m', `the steamexhaiist passages being also shown at 'n and n. Each ofthe sai d exhaust-passages opens at its inner end into one ofthe chambers b c of the valve, and at its outer end into the valve-case G.

Furthermore, there are two auxiliary exhaust-passages p p', which are arranged with respect 'to the main exhaustpassages u hf, in manner as shown in the drawing. l

Each of such passages p p may open at one end into a common ednct or discharge-pipe, and each of such passages should have a port or opening leading upward out of it and into the valve-case; such ports or openings being shownat q q', they being arranged with respect to the passages e e', iu manner as shown. i The novel features of the above-described ism may be stated as follows:

l First. The auxiliary passages ee', leading out of the mechanchambers b c of the piston.

Third. The opening of' each of the main exhaust passages a n at its opposite ends into Vthe valve-case.

These features, arranged and employed with others,

as hereinbefore described, will operate in manner as 'may be thus explained:

We will suppose the valve D to be'at the exact middle of the valve-chest C, that is, so that the pas-- sage d shalll be midway between the conducting-passages m m', leading from the `valve-ease to the two ends of the cylinder A. In this instance, the piston willY be at rest. Next, in order to start the engine, the valve should be moved endwise a little, or just far enough to cause the passage d tolap a short distance over one of the mouths of the passages m m. The

steam will next rush through the passage so over-i lapped, which we will suppose to be the passage fm,\`

and will enter the cylinder and move the piston there-k in. The exhaust steam'will escape from the cylinder through the passage mfand into the chamber e, from whence it will' owintn and' through the passage u', and into the valve-case and against one end of the valve, and, by its elasticpower, it will instantly move the valve endwise. The valve will continue its movement untilv thepassage e may have been 'carried b eyond the passage g.

During this movement of the valve, the main portion ofthe steam which may have been in advance of it in its case will escape through the passagesru f, the chamber b, and the passages e, q, and p. The steam remaining in the valve-case in advance of thc valve,

not being able to escape, will serve by its'elast-icity as a spring to cushion the valve.

During this movement of the valve, the passaged will have been carried fully over the mouth of the passage on, so as to supply the cylinder with the necessary amount of steam to complete the back stroke of the piston.

During this bach stroke, the arm k of the piston .Will be forced against one of the tappets or shoulders h z', and will more the valve, so as to lap the passage,

d a little ever the mouth of the passage m. The steam will next rush from the said passage d into and through the passage au', thence into the cylinder, andV will advance the piston. The exhaust steam in the cylinder will at once rush through the passage m into the chamber b, thence through the passages j' and n and into the valveec-ase and against the valve, which instantly will be driven by such exhaust steam` in a direction opposite to its former movement, and will continue to so move until the passage e shall have passed by the passage r1' and thevalvc been cushioned by the steam remaining in that part of the case which Should we dispense with the passages e e', We could not e'e'ot the cushioning of the valve, but still we' could e'ect its movements by thetexhanst' steam, and

' the escape of the balance of such exhaust steam.

What, therefore, I olaim'as of my invent-ion, is as follows:

I claim the combination and arrangement of the auxiliary exhaust-passages p p' q q and the main exhaast-passages n fn, with the passages -m m and with the valve D7 as constructed, with the chambers b c and A the passaves d, j; and f', and passages c e', substantially a's specified. v

ELTI NG POST. Witnesses:

l. H. EDDY, J. R. SNOW.

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