Improvement in osciluating steam-engines
US 36885 A
Descripción (El texto procesado por OCR puede contener errores)
VILLIAM D. ANDREVS rrn STATES OF NEV YORK, N. YQ
Sln-icilication forming-part ol' Letters Patel .To all whom it may concern.-
Beit known that I, WILLIAM D. ANDREWS, ofthe city, county, and State of New York, have invented certain new and useful Improveprovements in Oscillating Steam-Engines; an d 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 vertical section of'fan engine with my improvements, takenl longitudinally through the cylinder, steam-chest, and valve. Fig. 2 is a vertical section of the same, parallel with Fig. l, through one of the trunnionbearings.
Similar letters of reference indicate corresponding parts in the two figures.
rlhe first part of my invention relates to the construction ot' the oscillating engines with a valve-seat and valve arranged lengthwise of the cylinder in the form of cylindrical arcs concentric with the axis of oscillation, to enable the induction and ed uction of the steam to and from the cylinder to be effected by the oscillation "of the cylinder.
It consists in the construction of the valveface on the cylinder in an arc of such radius extending the whole length of the cylinder that if continued to a complete circle it would entirely circnmscribe the cylinder, thereby not only enabling it to be faced in a turning-lathe, but obtaining the greatest possible length of valve-seat andvalve, the valve-seat beingfaced to correspond, and its face being as much longer than that of the valve, and consequently than the cylinder, and keeping the whole length of the valve-face in Contact with it during the entire oscillation ofthe cylinder.
The second part of my invention consists in a certain mode of applying springs to the trun- Dion-boxes and in relation to an arc-formed valve face and seat arranged lengthwise of the cylinder, so as to permit the trunnion-boxes to adjust themselves to the expansion of the cylinder valve and seat whenever desirable.
To enable others skilled in the art to make and use my invention, I will proceed to describe its construction and operation.
A is the cylinder, arranged horizontally with the valve-face aon its under side. The form of this face is shown in Fig. 1, where it will be seen thatit is at such distance from the axis 0f the trunnions c that a complete circle, formlt No. Sl. dated November ll, 13672.,
ing a continuation of its are, would circumscribe the whole cylinder, such circle being represented in red color. This construction of the face enables the cylinder to revolve in a lathe about the axis of the trunnions, and so permits the trunnions to be turned and the valve to be faced without recenter-ing the c yl` inder in the lathe. The arrangement of the steamports d d in this vave-face is such that the distance between is equal to the width of the central port,f, in the stationary valve-seat b b, which is formed on the steam-chest B, the said chest being bolted to the bed-plate or framing F of the engine by bolts m m. The space e represented between the ports is si-mply to lighten the casting, and is open on each side to .the atmosphere. The valve-seat b b has provided in it the central port, f communicating with the steam-chamber g, and-two other ports, h hf, communicating with the exhaust chamberi. The cham ber g has connected with it the steam-pipe g from the boiler, and the chamber i has connected with it the exhaust-pipe z". The chamber i, pipe i', and ports h h may, however, be for the introduction of'stcam, and the chamber g, port f, and pipe g for the exhaust, which would cause the engine to work in the opposite direction to the first-mentioned arrangement. The valve-seat Z) is faced up to t the face of the valve by turning it, the steam-chest B B being placed in a lathe for the purpose. The length of the said scat exceeds thelength of the face a of the valve to the extent of the length of the oscillating movement of the valve-face, so that the valve-face always has a bearing in the seat throughout its entire length.
By making the valve-face of the full length of the cylinder and the seat so much longer they wear better and keep tighter, and this is effected without any more friction than if the surfaces were smaller, for the tendency of the pressure of the steam is to force the surfaces apart and not to press them together, and l' am enabled to make very large ports for the induction and eduction of the steam, thereby preventing choking or wire-drawing, and enabling the engine to run at a high speed.
Each trunnion-box G is arrangedin aplumber-block, D, one or more adjusting-screws, kk 7c, above, below, and on each side of it to adjust it upward, downward, or sidewise.
Between the top of the box and the uppermost screw or screws, 7c, there is placed a spring or springs, E, made of corrugated steel plate, as represented in Fig. 2, or of any other construction, the tension of the said spring or springs being so adj usted by the screw k as to make it just sufficient with the weight of the cylinder and piston to overcome the tendency of the pressure of the steam to raise the cylinder and keep the valve-face always in contact with the seat b, and the screw lc being so adj usted as to prevent the screw 7c from pressing the valve tcoo hard upon its seat.
Thespring orsprings Epermitthe trunnions to rise as much as necessary to compensate automatically for any expansion of the cylinder and valve-chest, and so prevents any exeessive friction from being produced between the valve and seat when the steam is used ata very high pressure and temperature, and keeping the valve tight under a low temperature.
Between the screw or screws k and the spring or springs E there is interposed a plate, l, to distribute the pressure of the screw over the spring.
G is the solid piston, made with grooves n n for the collection of Water of condensation to form a water packing.
His the piston-rod continued beyond the rear of the piston and passing directly through stuffing-boxes p p in both heads of the cylinder. By thus extending the piston-rod of an oscillating engine through both cy1inder-heads it is made to act upon the cylinder, to produce the oscillation on opposite sides of the trunnion at the same time, and thus the pressure and friction of the rod is distributed between the two stuffing-boxes, and the rod, being sustained at two points, is kept exactly in line with the cylinder, and the piston so far steadied that the Wear will be so very slight-Jess than in a stationary cylinder-that I amA enabled to use the solid piston, and thus save much of the expense of the construction of the engine, and avoid undue friction from pressure of piston -springs, which, especially in small engines, very materially reduces the power.
These improvements are also applicable to oscillating pumps.
What I claim as my invention, and desire to secure by Letters Patent, is
1. The construction of the valve-face on the cylinder in the form of an arc of such radius extending the whole length of the cylinder concentric with the axis of oscillation thereof that if continued to a complete circle it would circumscribe the whole cylinder, thereby not only obtaining the greatest practicable length of valve-face, but allowing the said face to be turned in a lathe while centered therein for turning the trunnions, substantially as herein described.
2. The springs E, applied in combination with the trunnion-boxes andl in relation to an are formed valve face and seat arranged lengthwise of the cylinder, substantially as and for the purpose herein specified. l
XVM; D. ANDREVS.
Witnesses R. GAWLEY, J. XV. CooMBs.