US355628A - topmillee - Google Patents

Description

(No Model.) 2, Sheets-Sheet 1.

B. TOPMILLER.

GUT-OFF VALVE.

'No. 355,628.. Patented Jan. 4, 1887.

N. FETEflSPMlu-Lilhngmpher. Washingim. D C.

2 t h S .w w. h S. 2 R E L L T M P 0 T (No Model.)

GUT-OFF VALVE.

No. 355,628. I Patented Jan. 4, 1887.

lJNiTE STATES rince.

BENNARD TO'PMILLER, OF CINCINNATI, OHIO, ASSIGNOR OF TW'O THIRDS TO SIMON OBERMAYER AND JACOB A. HEINSHEIMER, BOTH OF SAME PLACE.

CUT-OFF VALVE.

SPECIFICATION forming part of Letters Patent No. 355,628Idated January 4,1887.

Application tiled Decem er 3. 1884. Serial No. 119,424. (No model.)

steam-engines, and particularly to that class of cut-off valves in which independent laps are employed to control the admission-ports; and it consists of peculiar main and cut-off valves which are balanced at all points of theirstroke.

It consists, also, of independentlaps and means for actuating the same to control the cut-off at any point of the stroke desired, either automatically regulated by the speed of the engine under control of a governor or controlled by the engineer.

The invention will be first fully described in connection with the accompanying drawings, and the novel features particularly referred to and pointed out in the claims.

In the accompanying drawings, in which similar reference-letters indicate like parts whereverthey occur in the various views, Figure 1 is a vertical sectional view of a steamchest and valves embodying my improvements, shown mounted in position upon the cylinder, which is shown broken away. The section of the chest and valve in this view is taken through line a: a; of Fig. 2. section of the steam-chest, taken through line 3/ y of Fig. 1. Fig. Sis a side elevation of a steam-engine having the valve-actuating device attached. The valve box and cylinder are shown in vertical section, and the main valve isa modification of the form shown in Figs. 1 and 2. Fig. 4 is an elevation, upon an enlarged scale, of the driving-shaft and the eccentrics which actuate the main an d'auxiliary valves.

the point of out off through alever under control of the engineer.

Referring first to Figs. 1 and 2, the valvechamber A is in general form cylindrical, and has two heads, a a, provided with bearings, through which the axes of the valves pass. The valves and valve chamber are made Fig. 2 is an axial,

This viewillustrates a means to vary slightly tapering, similar to the ordinary plugvalve. The steam is admitted through port a and that end of the valve being the larger the pressure of steam will be sufficiently great to keep the valve'tight and compensate for wear by use.' The main .valve-B has four points of contact with the case A. These points cover, when the valve is in its vertical position, the ports 0 0 (Z d. There are in the main valvetwo ports, b Z), one through each end of the valve. These pass each other through the axes of the valve, as seen in dotted line, Fig. 1, and each extends from one of the cylinderports a or 0 to the port at or d, diagonallyopposite it. In theposition shown in Fig. 1 the valve B has just started to admit-steam into thecylinder, and has partially uncovered the ports 0 d for this purpose, and has also commenced to open the ports 0 d for the exhaust from the opposite end of the piston-cylinder. It will be seen by the arrows that steam is admitted back of the piston directly from the chest through port 0, and also indirectly through ports d I), while theexhaustis at the same time opened through ports 0 0 and 1/61. This provides for a rapid admission and exhaust, and the relief from the steam-pressure being equal upon all sides of the valve Bit is equallybalanced in every position. The smaller end of the chamber A is counterbored, as shown, so -as to prevent forming a shoulder as the circular valve-seat is worn by use. The cut-oft or valve C consists of two segmental laps mounted upon arms C and united by bolts 0". These arms have inwardly-projecting flanges, upon which the segments C rest. The main valve is oscillated by the shaft b which passes through the tubular bearings of the cut-oft valve. to receive the opposite bearing of the valve B. The pocket has a set-screw passing through it, to bear against the end ofthe shaft of valve B. The cut-off valve is oscillated by the tubular crank-shaft c, which has-one of its hearings in the head a. The other bearing is in the arm C, at the opposite end of the valve through which the shaft 12 passes.

Referring now to Fig. 3, and assuming that The smaller head, a", has a pocket, a,

mounted upon the cylinder, I will describe the means by which the valves B and G are actuated. -D is a bar, which is fitted to slide in stationary bearings d. One end of this bar is connected to the eccentric E in the usual manner and theother is connected to the crank 12 of the main-valve shaft If. The bar D and its two connecting-rods operate the main valve B just as the ordinary eccentric rods operate the common slide or rotary valves. F is a bar fitted' to slide in bearings j, which are stationary on the bar D. Upon the bar D, and between the two bars D and F, is journaled a cam, G, which has depending from it an arm, g. Upon pins projecting from the inner face of the bar F are two friction-rollers, one upon each side of the cam G. These are shown in dotted lines. The object of the cam G and friction-rollers is to give the bar F motion independent of the bar D; to produce a variable cut-off, which is accomplished by the means now to be described. Projecting up from bar F is an arm, f, which is connected to the crank-arm c of the cut-ofi' valve 0. The crank-pin of the cam-arm g is connected to aneccentric, H, which is fitted to slide around the drivingshaft alongside of the eccentric. The eccentric H has-a hub, 71 which projects within the flange or rim of a wheel, I, which is secured upon the driving-shaft in proximity to the cocentric. (The hub of the wheel I is removed and the arms or spokes of the wheel I are broken away to expose the parts back of them.) Projecting inwardly from the rim of wheel I are lugs t, and to these are pivoted swinging weights J. The opposite ends of these swinging weights J are connected by rods j to lugs 71 which are part'of the hub h. It will be seen that as the wheel I revolves the eccentric H will be carried around with it. K are spiral springs which, when the engine is at rest or running at a slow speed, draw the swinging ends of weights J toward the axis of revolution. In this position the eccentrics E and H coincide, and the arm 9 will be at and'remain in the perpendicular position. \Vhilc the arm 9 is in this position the arms 0 will always be at right angles to the side of the main valve, the relative position of the valves will be maintained, and the cutoff will only occur at full-stroke. As the speed of the engine is increased the weights J will be carried outward by centrifugal force and the relative position of the arms E and H will be changed. Thus when the heavy ends of the armsJ are thrownagainst the rim ofwheel'i the following lap G will close up against the following ends of the main valve before the admission-port is opened, and no steam will be admitted to the cylinderuntil the speed of the engine decreases. In the position shown the weights are in a position to cut off at about quarter-stroke of the piston. (The positions of the connecting-rods in Fig. 3 are shown in dotted lines.) In the position shown the piston of the engine has just completed its stroke and the valve B hasjust commenced to open in Fig. 3.

the port to admit steam back of .the piston. As the valve B is moved by its connectingrod the eccentric H acts on the bar F, through the cam G, with accelerated motion, and by the time the piston has reached quarter-stroke the following lap G will be closed up against the following end of the valve B, thus cutting off the steam. It will remain in this position until the piston has completed its stroke and the valve has returned to a vertical position, as shown in the drawings. If the speed of the engine is accelerated, the eccentric H will be carried around the shaft in the direction of the arrow and the valve 0 will be brought against the valve B quicker. If the speed of the engine should be decreased by a diminished pressure of steam,or on account of more machinery being put in motion by it,'thc weights J will drop inward and the lap G will close against .ply of steam will be regulated automatically,

keeping the engine at uniform speed,whatever the pressure of steam may be, or whatever duty may be required of the engine, and it will also be seen that as steam is admitted to and exhausted from the cylinder simultaneously by two admission and two exhaust ports a greater area for the passage of steam is provided than is possible with the same amount of valve travel in the old form of valves. The crank-governor shown in this figure is no partof my invention. It is old and well known, and is simply used to illustrate the means of automatically regulating the cut-off withmy peculiar formation of valve, and any of the well-known crank-governors may bereadily applied by any one skilled in the art without invention.

The form of valve shown in Fig. 3 difi'ers from the form shown in Figs. 1 and 2, in having but one opening through the valve to the auxiliary exhaust, and in having laps upon the upper sides of the valve B to prevent steam from the chest passing into the escape-port above.

In Fig. 4 I have shown a means to control the cutoff by a lever. In this View the eccentric-straps are removed and eccentric H is loosely j ournaled upon the shaft, the same as It has projecting from one side a. pin, L, which passes through the web of the wheel M. This wheel M has a feather or spline which projects into the'spiral groove m in the driving-shaft. It has also a grooved periphery to receive the shoes n, which are pivoted to the forked ends of the lever O, which is pivoted upon the stationary block 0. The wheel M is moved back and forth on the shaft by this lever, and as it moves in either direction is partially rotated, carrying with it the eccentric H. The relative positions of the cams E and H are the same as shown in Fig. 3that is, they are arranged to cut off at about quarterstroke. WVhen the wheel M is drawn up close to the cam, there is no cut off. WVhen it is drawn back to the position shown in dotted line, the eccentrics H and E coincide, and arm 9 of cam G will always remain in the vertical position and the bars D and F move together. Thecutbff valve 0 will therefore remain inactivethat is, it will always be at right angle to it and keep the same relative position. The cut off will then of course be at fullstroke.

The invention herein shown, so far as the tripping mechanism of the main valve and cut-0ft is concerned, is .an improved modification of the tripping mechanism shown in my pending application heretofore filed, and it is evident that these tripping devices may beused interchangcably,whether the valve be a rotary balanced valve, like the one herein shown, or asliding valve, as shown in my said application.

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

1. The combination, substantially as specified, of a cylindrical steam chest, an oscillating balanced valve to open the steam-ports, operated directly by the eccentric, and independent cut-off valves upon opposite sides of the main valve and having a movement independent of the main valve, with suitable mech' 'main valve by a bar, F f, controlled. by the variable eccentric H, substantially as specified.

4. In a tripping mechanism for cut-oft valves, such as described, the combination, substantially as specified, of bar D, mounted to slide in stationary bearings and having its opposite ends connected, respectively, to the eccentric and the main valve, with the bar Ff, mounted in bearings-seen red upon the slide D,

having one end connected to the crank-arm of the cutoff valves, and a cam, G, mounted upon bar D and having an arm, 9, which is connected to a variable eccentric, as H, and friction-rollers mounted upon the opposite bar, to be engaged by the cam G for the purpose of giving the bar F an accelerated movement to rapidly close the cut-off against the main valve when the variable eccentric is moved in advance of the rigid eccentric, either by the ac.-

celerated speed of the engine or by a lever under control of the engineer.

BENNARD TOPHILLER.

Witnesses:

GEo. JJMURRAY, GAsPER' MILEs.

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