US106886A - Improvement in cornish engines - Google Patents

Description

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JOHN STORER, OF PEEKSKILL, NEW YORK..

Letters Patent N 106,886, dated August 30, 1870; antcrlatcd August 18, 1870.

IMPROVEMENT IN CORNISH ENGINES.

The Schedule referred to in these Letters Patent a'xd making part of the Esame To all whom 'it may concern Be it known that. I, Jol-1N S'rounn, of Peekskill, m the county of Testchester and State of New York, have invented a new and useful Improvement in Cornish Engines; and I do hereby declare the following to be a. full, clear, and exact description thereof, which will enable those skilled in the art to make and use the same, reference heilig had to the' accompanying drawing forming part ot' this specification, in which dwawing- Figure l represents a sectional side elevation ot' this inveution.

Figure 2 is a front' view of the same.

Similar letters indicate corresponding parts.

This invention consists in the arrangement of an adjustable tappet in combination with the exhaustvalve of' the main steam-cylinder and with the cataract-cylimler in such a. manner that, by the action of the cross-head on the tappet the exhaust-valve of the niain cylinder is closed and the weight of the cataract-cylinder is raised and retained by a stop, and by v changing the position ot' the tapp'et the main piston can be arrested in its downward stroke at any desired point. i

The motion of the main piston is produced by means ot' an auxiliary cylinder, and the steam-valve of this auxiliary cylinder receives its motion through the cross-head and a turnier-rod, which connects with the valve-stein by a slotted brac et carrying an adjustable slide, in such a manner that, by adj nsting the slide in the slotted bracket, the rapidity of the valve motion ofthe auxiliary cylinder can be adjusted to the desired speed ot the main piston.

With the tappet-rod is combined an adjustable cam and a trip-dog secured in the cross-head, in such a manner that the steam in the main cylinder can be cnt ottA at any desired part of the stroke.

lhe piston in the auxiliary cylinder is provided with grooves and steam-passages, which 'are closed` by suitable lalves, and the steam-ports open into the cylinder, at certain distances from its heads, in such a manner that the steam in the ends ot' the cylinder is cushioned, and at the same time the steam is enabled to act on the piston at either end of its stroke.

In the drawinglhe letter A designates the steam-cylinder of a Cornish engine, which is 'provided with a piston, B, and which receives steam through a slide-valve, C.

This valve is so adjusted that it opens when the piston has arrived at the lower end ot' its stroke, the steam being employed to raise Ithe piston, while said piston descends by its own gravity, combined with the gravity of the machinery attached to it.

In order` to regulate the descent ofthe piston, a cataract-cylinder, D, iscombincd with tlie exhaustvalve E.

On the stem of this exhaust-valve is mounted a .double-armed lever, l), which connects at one end with a rod, c, that carries a. tappet, d, and on its other end with a rod, c, from which is suspended the tri p-weight f ot'thc cat-aract-eylnder.

l The tappet-rod c passes through the. cross-head F of the main piston7 and, as this piston approaches the lower end ot' its stroke, the cross-head strikes the tappet Za nd `the exhaust-valve is closed. At the same time. the trip-weight f is raised, anda stop-lever, g, catches under a dog, h, projecting from the stem ot' the exhaust-valve, said stop-lever being connected to a lever, i, which is subjected to the action ot' a spring, j.

lhe lever t supports the plunger h of .the cataractcylindcr, and as this plunger descends gradually and forces out the iiuid contained in the, bottom part ot'v j' against a spring catch, j", which is attached to a rod, and extending from said plunger up through the weight. j

When the. plunger has been lifted to the required height, the spring cat-ch is forced back by the action ot' a cam, f, attached to the cataract-cylinder, and the weight is permit-ted to rise the required distance, independent ot' the plunger.

lhe height to which the weight is thus raised may be regulated by a screw-thimble that serves to regulate the length ofthe rod e, and the correct position of the exhaust-valve can thus be insured.

The exhaust steam is carried through a pipe, t, into the upper part of the main cylinder, whence it passes ott` through a pipe., m, so that the cylinder is not allowed to cool olf.

ABy adjusting the tappet tl on its rod c, the time when the exhaust-valve is closed can be adjusted, and the main. pistonA can be cushioned inY its downward stroke to any desired extent, or its downward mot-ion can be arrested sooner or later, as may be re quired.

lhe motion of the main valve is produced by an auxiliary cylinder, l1", the valve of which is provided with a stem, n, that connects, by a friction-clutch, o, with a rock-shaft, p. j

On this rock-shaft is mounted a lever, q, which connects with a slide, r, that is adjustable in a slotted bracket, s.

This bracket is mounted on a rod, t, which slides up and down iu suitable guides, and which carries two tappets, u.

These tappe'ts are situated in the path of a dog, 11, projecting from the cross-head of the main piston, and, as the piston approaches the bottom end of its stroke, the dog c strikes the lower tappet u, the tappetrod is depressed, the valvel of the auxiliary eylinder ismoved, steam is admitted to said cylinder, and the main slide-valve is opened, so as to admit steam into the lower end of the main cylinder, and the main piston begins its up-stroke.

The rapidity with which the valve of the auxiliary cylinderis thrown depends upon the position' of theV slide 'r iu the slotted bracket s.

If this slide Yis moved toward the center of the rock-shaft p, a smaller portion of the stroke of the main piston is required to throw the auxiliary valve than if the slide is moved further from the center of the rock-shaft.

The slide 1* is adjusted by a screw, fw, which extends throughout the entire lengt-h ot' the slotted bracket, and the friction-clutch 0 serves to allow the rock-shaft to -follow the action of the tappet-rod beyond the stroke of the auxiliary valve.

By shifting the slide in the slotted bracket s, the valve-motion of the auxiliary cylinder can be adapted to the speed of the main piston.

'lhe dog o which acts on the tappets u, straddles a cani-rod, at', and it is subjected to the action of a spring, y, which has a tendency to force the same out toward the tappet-rod.

As the cross-head rises the dog c comes in contact with the cam 7 on'the rod x, and it is thereby forced back so as to release the upper tappet u, and the main pistou completes the balance of its Stroke without any further effect-v ou the tappet-rod t.

'lhe tappets u are so adjusted that thevalve of the auxiliary cylinder completes its stroke before the trip-dog w releases the upper tappet, and the camrod x is provided with a screw-shank and nut, so that the cam can be raised and lowered, and by 'these means the steam can be cut oli" at any part of the stroke of the main piston.

Tile piston G of the auxiliary cylinder isl provided with depressions, a1 a2, from which extend one or more openings, bl D, to the ends of said piston, and these openings are closed by valves c c?.

'lhe depressions' a* a2 are so situated that,wheu the piston hasfreached either end of its stroke, the corresponding depression is opposite one of the steamports d* di, these steam-ports being made to pass into the cylinder at a certain distance from its heads.

If the piston G moves in the direction of the arrow marked on it in iig. 1, the port Z1 will be closed before the piston has reached the end of its stroke, and the steam which has not time to exhaust will cushion said piston.

During this lnotion, the valve c is` closed by the pressure of the steam. Y

It' the piston has reached the end of its stroke, the depression al cornes opposite the port dl, and as steam enters throught-his port it passes through the openings bl and lifts the valve cl, so as to drive the piston down.

By this arrangement a simple way of cushioning the piston is produced, and it is obvious that this arrangement is applicable to all steam-cylinders, provided their ports are properly situated.

I am aware that a compensatingr mechanism composed qf a hinged lever and a tappet-rod, one of which is made adjustable, in combination with an auxiliary cylinder, the piston of which actuates the main valve, is not new, a similar arrangement being shown in my patent of September 7, 1869; I donotptherefore, broadly claim such compensating mechanism without reference to its peculiar construction.

What l claim as new, and desire to secure by Letters Patent, is

1. The tappet-rod c, lever b, valve E,and stop-lever g, with the cataract-cylinder D, and cross-head F of the main cylinder, substantially as vshowu'and described.

2. The rod t, carrying the tappets u, and the slotted bracket s, in combination with the lever q, rockshaft y, diction-clutch o, and valve-stern of the aux'- iiiary cylinder E' and with the cross-head of the main cylinder, snbstmftially as set forth.

3. The mechanism herein described for cutting olf the steam at any part of the stroke, consisting of a I trip-dog secured in the cross-head or any other part attached to the piston-rod, and of a device for releasing said trip-dog` at the required point, substantially as herein set forth.

4. The depressions al ai, openings?)l b2, and valves c c2, in the piston of a stean'i-cylinder, constructed substantially as set forth.

JOHN STORER.

Witnesses W. HAUFF, E. F. KASTENHUBER.

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