US154363A - Improvement in cut-offs for steam-engines - Google Patents

Description

UNIT-Ensures 'PATENT' OFFICE.

4DAivinL A. wooDBURY, oRocHEsTER, NEW YORK.

lmp'RovEMl-:NT IN Vcu-r-oFFs FpoR STEAM-ENGINES- Specification forming `part of `Letters Patent o. 154,363, dated August 25, 1874; application tiled i i February 20, 1874.

To all whom t may @encarar Be it known that I, DANIEL A. WOODBURY,

of Rochester, in the countyoil Monroe and State of New York, have `invented certain Improvements in .Automatic Cut-Offs for Steam-En# gines,of which the following is a specification: The object of my invention is to provide a simple, durable, and ett'ective cut-oft gear which `f` can becontrolled with ease by thegovernor;

and lit. consists chieiiy in the useof .a balanced cylindrical cut-off valve sliding in a chamber in the back of the mainvalve, and Aarranged to admit steam? into passages in the latter by means of spiral ports inthe cut-ofi' valve-seat,

the point of 1cu't-oftfbeing determined by roll` ing'the valve in its seat, and it further con- "ffsists in a method of compensating the4 wear of the valves and. seats. 1

In the drawing, Figure l is a'horizontal sectional view of my device .applied to the steamchest of a side engine. Fig'. 2 is a vertical sectional view of the cut-oft' valve and connections, showing those parts 'above the dotted line Fig. 1. Fig. 3 is a transverse section of the valves at the dotted line y, Fig. 1.

A, Figs. 1 and 3, is the main or distributing valve, moving upon a face on the cylinder B in the usual manner, and having the ordinary exhaust-passages, and also steam-passages c c,4 communicating with chambers formed in the back of the valve. Gis a cylindrical cut-0E valve tted closely into a seat provided in the main valve. This valve admits steam from the chest D at its ends, and ports a a are provided in its seat, which communicate, through the chambers before mentioned, with the steamopenings c c in the face `of the main valve, as indicated by full and dotted lines .in Figs. 1 and 3. The ports a a are cut spirally around the valve-seat, there being two or more openings near each end around the periphery of the seat, as shown in Figs. 1 and3. The extremities of the valve C are also of spiral form, to correspond with the ports a a, and there are consequently two or more spiral admissionedges, b, at each end, one foreach port a. The valve C is reciprocated in its seat by means of the stem d and the usual eccentric attachments, and it is plain that, if a rolling movement be imparted to it through the stem d, the point of cut-off will be varied, since the length of .the valve is thus virtually altered.

It will be seen that by this construction of `valve and arrangement of ports the former is perfectlyV balanced, the steam pressing upon `it equally in all directions, whether the ports be open or closed, and that thus the force necessary to work it is reduced to the minimum, and, at the same time, it is perfectly free to be rotated by the governor through suitable couynections. The latter, particularly, isa great desideratum, since in the valves of this class heretofore used the pressure upon them, when a port was closed, was so great as to hinder, if

, not actually prevent, the action of the governor.

y The spindle d passes freely through the valve C to that extremity opposite the sturling-box e, and is rigidly fastened to it by a set-screw, j', Fig.' 1,v or other suitable device. By this .means the elasticity of. the rod is made available to allowthe valves to wear upon their seats within certain limits, and also to permit the main valve to retreat in case of water gathering in the cylinder. By thusmaking the distance between the stuffing-box and the point f considerable, the attachment of the valve to I the rod is much simplied, for it is found necessary to make some provision for change in position of the valves, and this plan allows the change to occur as necessity requires, within small limits.` The valve-stem d is secured at its outer extremity to the sleeve or enlarged rod g, Figs. 1, 2, and 4, which is supported in bearings inthe bracket E. This bracket is Y.

bolted steam-tight to the face of thev steamchest D, and receives the stuffing-box e. The sleeve g has a ball-and-socket joint at its extremity, which forms the attachment `to the eccentric-rod, and is provided with longitudinal grooves, (shownin Fig. 4,) into which splines in the arm t it. This arm is located between the two bearings m and n of the bracket E, and consequently has no lateral movement, but permits that of the sleeve g through it. The rod j is pivoted to the outer end of the arm t', and proceeds to au ordinary centrifugal governor or other suitable regulating device. Thus it will be observed that the sleeve g, stem d, and valve are free to move longitudinally in vobedience to the eccentric, while, at the same amounts of adjustment. lThe upper face of time, a circumferential movement may be im. parted to -them through the splined arm, thus adjusting the point of cut-o'. The openingl in the Wall of the steam-chest, through which the stem d passes, is considerably larger than such stem, and the bracket E is made adjustable along the face ofthe steam-.chest by means of slotted bolt-holes or otherwise. By this means, when the Wear of the valve-seats becomes greater than the elasticity ofthe rod d is able to compensate, the stuliing-box and supporting-bearings of the valve-stem may be adjusted to correspond with such Wear, and in the case of a side engine, with the settling of the valve upon its supporting-surface also. This adjustment of the bracket E is not a substitute forthe compensation obtained by the elasticity of the rod d, but is intended as an adjunct thereto, that derived from the rod being automatic and Within small limits, While the other is available for larger and fixed the bracket E also affords a convenient base for the support of the governing device, in case such location is desirable.

The cnt-off valve may be a hollow cylinder, having suitable provision for attaching the stem d, and, instead of the admission-edges b, spiral openings may be formed in its shell, the operation being the same in eithercas'e.

The ball-joint h permits the rolling movement of the rod g, and also the vertical swing of the eccentric-rod; and it Will be observed in this, as Well as in regard to the frictional surfaces of the sleeve g, rod d, and valve C, there is a continuous positive movement imparted 4 vloy the eccentric, which greatly facilitates the other part of the valve C, and the flexibility of the valve-stem still retained.

I am aware that slide-valves having a rolling adjustment in their seats, in connection with spiral vor diagonal ports and corresponding admission-edges on the valves, are in u se, and I dol not claim such construction of valve and arrangement of ports; but

What I claim as my invention is- 1. The cylindrical cut-off valve C, provided with ports or admission-edges b, and capable of a rollingadj ustment in its seat in the main valve, in combination with the main valve A, having spiral ports a and passages c, substantially as and for the purpose set forth.

2. In combination With a valve, C, having a rolling movement in its seat, the stuffing-box e, made adjustable along the face of the steamchest laterally to the valve-spindle, for the purpose of following up the Wear ofthe valve and seat.

3. In combination with a valve, G, having a rolling movement in its seat, the bracket E, supporting the stufing-box e and spindle-bear-A ings m and n, and 'capable of adj ustmentV along the face of the steam-chest, substantially as'- and for the purpose set forth. l Witnesses: D. A. WOODBURY.

JAMES E. BOOTH, WM. A. MONTGOMERY.

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