US85289A - Improvement in steam-engine exhaust-valves - Google Patents

Description

"te idem/tl agraire @am Letters PatentpNo. 85,289, dated December 29, 1868 lmtedcted December 23, v186e'.

IMPROVBNIENT IN STEAM-ENGINE EXHAUST-VALVES.

The Schedule referred to in these Letters Patent and making part of the same.

* o-OrFw- To all persons to whom these 'presents shall come Be it known that I, THOMAS S. Davrs, of Jersey City, in the county of Hudson, and State of New Jersey, have invented a new and improved Attachment to or Construction ofthe ExhaustPassages to Engines and that the following description, taken in connection with tlie accompanying plate of drawings, hereinafter referred to, forms a full and'complete specification of the same, wherein I have set forth the nature and prineiples of my said improvement, by which my invention may be distinguished from all others of a similar class, together with such parts as -I claim, and desire to have secured to me by Letters Patent.

The principal object of the present invention is .to prevent the access or passage, through the exhaust or eduetion-ports or passages of locomotive oi' other engines, to the valvechests and cylinders of the same, 'of cinders, heated air, and other. detrimental matter; and, for-this purpose,

The invention consists in the arrangement, within` the exhaust or eduction-ports or passages of locomotive or other engines, and at. any point or points of their length, of a valve or valves, whereby they can freely open,` to allow the exhaust-steam to escape from the cylinder, and close the moment the pressure withinzthe cylinder becomes equal to or less than that of the at mosphere within'the smoke-box, so that the entrance of all deleterious matter, such as cinders, heated air,.

86e., to the cylinder or the valve-chest is eii'eetually and entirely prevented.

.In t-he accompanying plate of drawings, my improved arrangement of the exhaustepassages to engines is illustrated- Figure l being an elevation of the portion of an exhaast-passage having a valve arranged in it according to the present invention;

Figurev 2, a plan or top view of the exhaust-passage shown in iig. l; and

Figure 3, a vertical section, taken in the plane of the line :c iig. l. Q

A, in the drawings, represents an exhaust-passage or tube.

This tube A, at its lower end, is provided with two openings or ports, one alongside of the other, to which pipes or tubes, shown in red lines in the drawings, are to be attached, for forming a connection between the passage A and the exhaust-ports of the steam or piston-cylinder to an engine. v i

`The upper end, A2, of' the tube A, when placed in position upon a locomotive-engine, is arranged thereon so as to open into the smoke-chamber of the same, and thus allow the exhaust-steam, passing through the said tube from the cylinder, to escape into the said chamber.

B, a dislevalve, having a centre-stem, c.

This valve B is within the tube A, and, at D, is provided with a seat, E, for it to rest upon, and, above such seat, 'with a fixed cross-bar, F, for its stem to play 'heated air, or other deleterious mattei', to the cylinder or `valve-chest, the valve being only arranged to open upward, for the passage of the exhaust-steam to the -With a valve arranged for operation within the exhaust-passage of an engine, substantially as above described, it is plainly apparent that, while but little obstruction is given to the escape of the exhaust-steam from the cylinder, the entrance of cinders, smoke, coal` dust, heated air, or other deleterious mattei' from the smoke-chamber, to the cylinder or valvechest is entirely and effectually prevented, a result ofthe utmost importance and'advantage in the running of a locomotive-engine more particularly, as, for instance, when the engine is running without steam in the cylinders, and by Aits previous acquired momentum, or when the engine lis reversed, in order tol stop quickly, for thereason that, in such cases, without-the said val ve, there.

wouldvbe no hindrance to the passage of cinders, Sac., from the smoke-chamber to the cylinder and valvechest, which einders, &c., being gritty, would cause great injury'to the,pistons and valves, as welll as to the cylinders and valve-chests, 4finally destroying and rendering them useless.'

And it may be here observed that, while the safetyvalves of most locomotive-engines are suiicient for all ordinary purposes and occasions, they are greatly defeotive in this respect: that they allow, even when wide open, the pressure in the boiler to accumulate to a fearful extent at times, as, for instance, when the engine, with a heavy train, is moving over a down grade, and it becomes absolutely necessary, for safety, to cheek the speed ofthe train by reversing the engine; for, if then the pressure upon the pistons be not suiicient to hold the driving-wheels, or to turn them backwards, the air from the smoke-box is necessarily pumped into the boiler, thus'raising the pressure therein much faster than the safety-valves are able to relieve it, and, as a consequence, either exploding the boiler or collapsing the tubes, the latter. more 'generally being the result. This effect, as is obvious, is a source of great annoyance and expense to roads that have heavy gradesfand necessarily heavy engines to run their trains; and, con`- sequent/ly, in lieu of reversing the engine, the engineers generally depend upon the ordinary brakes of the cars to retard or hold the train, which are not only complicated, but expensive in arrangement, while, if the engine could be reversed without danger of exploding the boiler or collapsing the tubes, no better or more perfeet'and sure brake could be had; and by my invention, as is manifest, the engine is so enabled to be employed, without the least danger thereto or to its boiler,

as the inward passage or pumping of the heated wir, 85o., from the smoke-box cannot possibly occur, but is entirely prevented.

In addition to the several`znlvzn1tages ztnd results above stated as secured by my invention, it may be well to here observe that, as another consequence of the exclusion of gritty particles, heated air, Sie., from the cylinders and valve-chests of an engine, less oil is required to be employed to keep the cylinders, Ste., lnbxicated, as the full e'ect ofthe steam, for sncb purposes, is secured, (steam being well known to be :t suicient lubrieator therefor) thus reduci n g, in that respect, the expense oi' running the engine.

By tlle'arrengement ofthe valve B, above described, it is left free to close by its own gravity, or by the pressure of the :atmosphere within the smoke-box but springs may be employed in connection with it, if so desired.

In locating the valve within Vthe exhaust-passage, l'

prefer, for convenience, to `place it at the extremity oi"

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