Improved valve for steam-engines
US RE921 E
Abstract available in
Claims available in
Description (OCR text may contain errors)
ADDISON CROSBY, OF FREDONIA, NEW YORK.
IMPFKOVEDY VALV `FOR STEAM-ENGINES.
Specification forming part of Letters Patent No. 25,248, dated August 30, 1859 Reissue No. 92|, dated March (i, 1860.
To all whom, it may concern:
Be it known that I, ADDISON CRosBY, of Fredonia, in the county of Chautauqua and IState of New York, have invented a new and Improved Valve for the Induction and Eduction of Steam to and from Steam-Engines, and for other Purposes; and I do hereby declare that the following is a full, clear, and exact description of the same, reference being had to the accompanying drawings, forming part of this specification, in which- Figure l is a transverse section of the valve. Fig. 2 is a longitudinal view ofthe same. Fig.
3 is a central longitudinal section of the cylinder of a steam engine, showing the manner of applying a set ot' such val ves for induction an d eduction.
Similar letters of reference indicate corresponding parts in the several iigures.
My invention consists in a valve of the oscillating kind, constructed as hereinafter described, with an .opening through it, and with two opposite faces eccentric to its axis of oscillation, and fitted to a double seat of correspondently eccentric form, which contains opposite ports or openings which are covered and closed by the faces of the valve whenever the valve bears upon its seat, such valve, when used in a steam-engine or other apparatus in which there is pressure of steam or other tluid, being subject, when closed, to just sufficient pressure ot steam to keep ittight, but very perfectly balanced as soon as it commences opening, and in all its applications Working entirely without friction between its fa 'res and seat.
To enable others skilled in the art to make and use my invention, I will proceed to describe its construction and operation.
A, Figs. l and 2, is the valve, composed of two eccentricsegments united at one or both ends, and provided with a journal, j, at either or both ends, to work in a suitable bearing in .the end of the valve box or side of the steamd is the opening through the valve, extending nearly from one'end to the other between' the two eccentric segments. The seat for this valve has two faces, e e, which correspond in form with the faces a a of the valve, so that the valve may tit steam-tight therein, and in Y each seat there is a port, f. I propose gener- Y ally to make the seat in a box, which can be inserted within the steam-chest or other place where the valve is to be used and removed therefrom with facility.
In applying my improved valves to a steamengine a set of four is necessary-viz., two for induction and two for eduction,the inductionvalves being arranged on one side and the eductionvalves on the opposite side of the cylinder, as shown in Fig. 3, where A A represent the induction and A A the eduction valves. The valve-boxes B B, which contain the induction-valves, have a somewhat diti'erent arrangement of passages in connection with their ports f f to the arrangement in the boxes B B', which contain the eduction-valves, but these arrangements ot' passages need no particular description, as it will be obvious to the engineer that the arrangement may be varied almost indenitely. The direction in which the steam passes through the valves, ports, and passages is indicated in Fig. 3 by arrows.
It will be readily understood by reference to the dotted outline of the valve in Fig. l, representing it open, and by reference to the lefthand induction and the right-hand eduction valves in Fig. 3, that as soon as the valve is opened in the slightest degree it is entirely surrounded by steam, and so perfectly balanced.
It wi-ll also be understood by a comparison ot' the boldoutline and the dotted outline of the valve in Fig. l that as the valve opens its faces leave the seat, and that it is on" y while the valve is closed that it touches the seat, and hence it works without any friction Lbut that of its'journal or journals, which is incons-iderable, and without any wear of its faces; and it will be understood by reference to the lbold outline of the valve in Fig. 1, and to the right-h and induction-valve and left-hand eduction-valve in Fig. 2, which are closed, that the pressure of the steam on the excess of surface presented by the sides g g of the segments of the valves will tend to keep the valves closel tightly. This excess of surface is, however, so slight that the pressure upon it causes comparatively little resistance to the openings of the valves.
This valve, it may be observed, bears some resemblance to two Well-known kinds of valves-viz.,the butterfiy-valve and the rolling valvebut yet diifers essentially from both. It resembles the butterfly-valve in its having two eccentric faces, but differs from it in having an opening right through it between its faces, and in having its ports opening into the `faces of its seat so that they are closed by being covered by its own face, and, further, in its spindle never being subject to lateral pressure.` In its construction it resembles some ot' the rolling valves in all essential points but in the eecentricity ot its facesand those of its seat, and this point of difference changes entirely the character of its operation, for it is spondently eccentric form, which contains opposite ports or openings that are covered and closed by the faces of the said valve Whenever the said valve is in Contact with the said seat, substantially as herein described.
ADDISON CROSBY. Witnesses:
W. THoMPsoN, v M. M. LIVINGsToN.