US296403A - goodwin - Google Patents

Description

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W. P. GOODWIN GUT-OFF -MECHANISM. l No. 296,408, Patented Apr. 8, 1884.v

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W. P. GooDWN. GUT-OFP MEGHANISM. No. 296,403.

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W. F. GOODWIN.

GUT-OPF MBGHANISM.' No. 296,403. Y Patented Apr. 8, 1884'.

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XVILLIAM FARB GOOD'VIN,

on STELTON, NEW JERSEY.

CUT-OFF MECHANISM.

SPECIFICATION forming part of Letters Patent No. 296,403, dated April 8, 1884. Application filed May 9, 1863. (No model.) Patented in 'England May 23, 1833, No. 2,594.

.To @Z whom it 'may concern:

Be it known that I, VILLmn FARB Goon- I WIN, a native citizen of the United States, re-

siding at Streiten, in the'county of Middlesex and State of New Jersey, have invented certain new and useful improvements in cut-off mechanism for actuating the induction-valves of steam-engines, so as to obtain a variable cuto', automatic or otherwise; and I do hereby declare the following to be a full, clear, and exact description ofthe same, reference being had to the accompanying drawings, which form a part of this specification, in which-4 Figure l is aside elevation, partly in section, of a cylinder and valve mechanism of a horizontal engine wherein the cut-off is varied automatically by a governor, showing the relative positions of the valves and cut-off mechanism when the port I at the back end of the cylinder is open. Fig. 2 is a side elevation oi' the same, showing in dotted lines a diagram of different positions of the cutoff mechanism and the position of the latter when the port I is closed, Fig. 8 is a side elevation of the cylinder and valve mechanism of a vertical engine wherein the cut-0H is varied by adjusting the center of motion of the rock-beam by means of a screw.

The same letters and gures of reference indicate the same parts in the different figures.

My invention relates to improved cut-offvalve mechanism for actuating the inductionvalves of steam-engines, whereby a variable cut-on is obtained, automatic or otherwise; and it consists, essentially, of two radiusarms and a coupling-link by which the swinging ends of the arms are coupled together, one of the arms being pivoted on the valve-spindle, and the other at a proper distance from the latter, to permitthe swinging ends ofthe coupling-link and radiusarm to pass through a straight line, with their centers of motion actuated by a rod connected with an eccentric motion, the combination and arrangement being such that the intermediate link or coupling-rod and the rockarm act together as a toggle, whereby a varying speed is imparted to the valve, the cut-off taking placewhen the valve is moving at its highest speed. for each valve is a complete system within it- 'lhus the cut-oft mechanism` self` and independent of the other, and could be operated separately; but for simplicity of construction and operation I-prefer to form operatingthecutoti mechanism of both valves. l v

I also form on the double-armed lever a third arm at right angles to the former, by which it is oscillated through suitable gear actuated by the eccentric, the effective length of this arm being adjustable, if desired, for varying the angular motion of the double-armed rocking lever."

In order that those skilled in the art to which my invention appertains may understand how the same is made and used, 'I have illustrated it in the accompanying drawings, and will proceed to describe it with reference thereto.

Referring to the figures and letters of the drawings, the valves V V', preferably selected whcrewith to illustrate my invention, are of the cylindrical type, and work in chambers lacross the cylinder-covers at each end of the cylinder, the valvespindles projecting to rcceve the crank-arms C O. In order to distinguish the two ends of the cylinder in the description of the movement, that end nearest the crank is called the firent-L7 end and the other the back end, and Fig. 'l is placed by the letters at the front end.

rV' V are the induction-valves, and J and J the exhaust-valves. The gear about to be described applies only to the former. The latter may be operated by a similar rocking lever.

without adjustment.

A A is the rocking beam, and B B the links coupling it to the crank-arms C C or" the valvespindles. The beam is pivoted atV on a bearing ,movable in a slot, and carried by a link, l?, pivoted to theslide-block S and to the end of the lever L. The beam or lever AA A is T-shaped, its third arm, A', being slotted to `receive a slide-block, S, attached 4by a pivot, V, to the end of a rod, R, and supported in the slotted arm A by a radius-link, q, pivoted to la iixed point, D. Thus arranged, by raising and lowering the center of motion, W, of rock-lever A A, the effective length of arm A IOO is altered, and the relative positions of the various centers of motion are also altered, thus varying the cut-off.

The governor-lever L is pivotcd at W3, and receives motion from any suitable governor for varying the position of the center of motion of the rock-lever A A. The other end of the rod R is connected at VV2 to a slide-block, S2, received in a slot, T, in a link, K', and earried by link P', joined to the other end of lever L. The link way or slot T is in one piecewith the arm K', supported by a radius-arm, Y jointed to it at E.

B' is an eccentric rod taking hold of the same wrist-pin, E, and B`Z is another eccentricrod joined to the end of link-arm K', and reeeiving (through suitable gear not shown) motion from the same eccentric at an angle to the motion imparted to rod B', thus imparting a compound motion to the link-arm K' and its slotted way T. The second element of this eccentric motion is for the purpose of maintaining a uniform steam admission, while the cut-off is varying and may be varied in any degree within the limits of the slot T and motion of adjusting-lever L', or may be entirely dispensed with when other means are employed to maintain the desired moment of steam admission, in which case the link-arm K' will take the place of the radius-arm Y, the lever A A then receiving its motion d'irect from the eccentric. With the complete arrangement shown, however, the action is quicker'.

The relative arrangement of rock-lever A A, connecting-links B B', and crank-arms C C' of the valves is such that the angular distance traveled by the` ends A A of the rock- -lever is much greater than necessary to open and close the valves, the position of the parts at the moment of opening and closing either valve being such that its respective connecting-link B or B is at about right angles to the lever A A and crank-arm C or C', the latter thus at this moment moving at the same speed as the end of the rock-lever A A, while at other times, when the valves are shut, the motion of the lever A A is more or less lost on them by reason of the links B or B' coming into and passing across a straight line with the lever A A to an angle on the opposite side of the line. The valves thus have a high speed at the moment of opening and closing, without having an amount of travel which would be commensurate with the speed if it were uniform.

Referring to the diagram of motion in Fig. 2, a' represents the position of lever A A when the piston is at the beginning of its forward stroke. AtthismomentthevalveVattheback end of the cylinder is beginningto open, and will continue to open until the lever A A assumes the extreme position a, in which it is shown in Figs. l and 3, at which time the valve V is full open. By the return motion of lever A A the valve is closed when the lever arrives again at position a', (shown in full lines in Fig. 2,) which is the position it occupied when the piston-stroke commenced. During these movements the valve V' at the front end of thecylinder was moved in the same direction as that in which it closes and back again. Both valves remain closed until position c is reached, which is the mean position of the lever, both valves then covering the inductionport to the same extent and with a long lap. Upon the piston arriving at the end of its forward stroke, the lever A A assumes the position as, when the induction-valve V' at the front end of the cylinder is on the point of opening, and by theY continued motion of the lever A A is opened and closed in the same way as was previously described in reference to the valve V at the back end, which itself again receives a similar motion to that previously described in reference to the valve V' at the front end.

It will be readily seen that varying the positions of the centers of motion relatively to the valve-centers will vary the moment of cut-off relatively to the piston-strokes. The varying of the position of the center of motion of the lever A A may be effected by the governor, as before described, or by any other suitable means. If this center of motion be raised, the valves cut off earlier until the center is raised to its highest position, when no steam will be admitted, and if lowered the valves cut off later until steam is admitted for the full stroke. As arranged in Figs. l and 2, it will be seen that when the center of motion of lever AAis raised the block Sl is lower in the slot T, and vice versa, thus coaeting with the variation IOO of the effective length of the arm A' of the le- 4 ver A A, to vary the extent of motion of the lever A A; but, as before mentioned, either of these two adjustments may alone be used; and, if desired, two motions to the pistonstroke can be imparted to the center of motion, W, of lever A A, the downward motion terminating at each end of each piston-stroke and the return or upward motion terminating at the middle of each piston-stroke. Any suitable toggle-j oint gear actuated by the eccentric or otherwise would serve to impart the two motions to the center of motion of the lever A A to each stroke of the piston. Thus arran ged,the valves would open and close quicker byreason ofthe compound motion of lever A A.

For cheaper engines, the rock-lever A A may be carried on a fixed pivot, when the cutoff will be varied by varying its angular motion by means of a slotted link, as shown, or otherwise.

Any suitable means by which the extent of angular motion of the lever A A and links B B' is increased and decreasedwill effect the cut-off. Also any suitable means by which either of the previously-described adjustments of lever A A c anbe operated, separately or two or three together, will effect the cut-off. s

It is readily understood that the rocking mo- IIO tion of lever A A, links B B, and cranks C C',

communicated to the valves, effects the cut-off,

and that any suitable means whereby the lever A A and links B B are rocked, whether applied to one or both ends of the lever A A or to the arm A', as shown in the drawings, the effect would be the same in all cases when the same motion is imparted to the rock lever or levers A A and links B B; hence it is not necessary to describe all the divers methods by which motion can be imparted to the adjustable toggle-cut-off mechanism which constitutes my invention. l. have illustrated such as I have used in practice.

l do not confine my claims to any particular type of valve7 it being as `follows: that the variable motion ofthe crank-arms() C', through their spindles, can be imparted-to other types of induction-valves than that shown. p

Having described the nature of my invention and its mode of operatiomwhat l claim as new and desire to secure by Letters Patent, is-

1. In combination with the induction-valves of a steam-engine, the adjustable lever or rock arms A A A', links B, B', crank-arms C C', pivot NV, and rod R, combined together into a working system, in the manner and for the purpose substantially as described.

' 2. In combination with the levers A A A', linksB B, crank-arms C C-Qvalves V V", and rod R, the adjustable pivot-bearings S, S', and S, slot K, support D, and link q., arranged to operate in the manner and for the purpose substantially as illustrated and described.

3. The lever or combined levers A A A, links B B', crank-arms C C', the link-arm K', slot T, pivot lf f2, and rods It andB, combined together and arranged to operate in the manner and for the purpose substantially as illustrat-ed and described.

VILLIAM FARB GGODWIN.

Vitnesses:

ROBERT GRIMsHAW, VICTOR S. DnLAonoDr.

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