US24707A - wood and henry howson - Google Patents

Description

WASHINGTON D C N-PETERS. PHO

A'UNITED sTATEs PATENT oEEIoE.

WVM. W. W. VOOD AND HENRY HOWSON, 0F PHILADELPHIA, PENNSYLVANIA, ASSIGNQRS TO JNO. RICE, OF SAME PLACE.

DEVICE FOR OPERATING CUT-OFF VALVES OF STEAM-ENGINES.

Specification of Letters Patent N o. 24,707, dated July 5, 1859.

T o all whom it may concern:

Be it known that we, VILLIAM lV. W. WOOD and HENRY HowsoN, both of the city and county of Philadelphia and State of Pennsylvania, have invented a new and Improved Positive Power Attachment to the Governors of Steam-Engines; and we do hereby declare the following to be a full, clear, and eXact description of the saine, reference being had to the accompanying drawing and to the letters of reference marked thereon.

Our invention consists in causing the positive power of the engine to operate the throttle valves of steam engines, by the employment of t 7o vibrating, reciprocating or rotating strikers, actuated by any positive movement of the engine, in combination with two inclined planes intervening between the said strikers and the valve or appliances connected therewith; any ball or other governor being so connected to the strikers or to the inclined planes, that the movement of the governor, caused by any increase or diminution in the speed of the engine, shall change the position of the inclined planes in respect to the strikers, or that of the strikers in respect to the inclined planes, the latter being thus the intermediate means of regulating the amount of opening of the valve, to correspond with the speed of the engine, while the actual movement of the valve is effected by the power of the engine itself.

The object of our invention is to render the movement of the throttle valve as certain as the movement of the engine itself, and, at the saine time, sensitive of the slightest alteration in the speed of the engine, results which governors have been insufficient of themselves to accomplish, especially when applied to marine engines.

In order to enable others to make and use our invention, we will now proceed to describe the modes in which we carry it into effect.

On reference to the accompanying drawing, which forms a part `of this specification; Figure l, is a plan view of our positive power attachment to governors. Figs. 2 and 3, end views, looking in the direction of the arrow, Fig. 1. Fig. 4, a View, showing a modified forni of our invention. Figu 5, a sectional view of Fig. 4. Fig. 6, a plan View of Fig. 4. Fig. 7, another modification of our invention.

On reference to Figs. l, 2 and 3, A is a lever connected to any ball, vane or other governor now used for regulating the admission of steam to the valve chests of steam engines, this lever vibrating on a pin attached to a bracket a or other suitable attachment, and the movement of the lever depending upon the speed of the engine, in the same manner as the ordinary throttle valve lever of other governors. The short arin of the lever A is forked, and the forked ends have pins fitting into a groove in the sleeve B, which is arranged to slide up and down as well as to turn freely on a stationary pin C. Two bent arms b and b project from and form a part of the sleeve B, the arms having wedge shaped terminations, with straight perpendicular faces on the outside, parallel with the center line of the pin C, and inclined faces on the inside, the inclinations of both being precisely at the saine angle and parallel with each other. 0n the same stationary pin C a lever D is so hung, as to vibrate loosely, its proper vertical position being maintained by collars, pins, nuts, or other suitable attachments. A posi-A tive and limited vibrating motion is iin` parted to this lever, by rigid connections with any working part of the engine, The lever D has two projections al and d one on each side of and at equal distances from its center. The end of the projection d coincides wit-h the perpendicular surface of the wedge c, and the projection d with the per-V pendicular surface of the wedge c. To the same permanent pin C, another lever E is hung loosely, and maintained in its proper position vertically by collars or other appliances. The end of this lever is connected, by any suitable system of rods and levers, to the throttle valve of the steam engine. In the present instance, it is illustrated as connected to an ordinary plate valve F by means of a rod e, an opening f in the plate G, on which the valve slides, representing the coniinunication between the steam pipe and the -valve chest of the cylinder.

The lever E has two curved projections 71. and L, one on each side, the projection h being inclined so as to coincide with and so as to itsnugly against the inclined face of the Wedge. 0, and the end 0f the projection h being also inclined in a contrary direc-r tion, so as to coincide `with and fit snugly against the inclined face of the wedgecf, as seen in Figs. 2 and 3. Y

Vhen a sudden diminution kvin the speed of the engine has caused the governor to elevate the lever A, the sleeve B with its wedges will' have been depressed, and have assumed the position illustrated in Fig. 2, so that the thickest portion of the wedge c will intervene between the projection d on the lever D and the projection it on the lever E, the thinnest portion of the wedge c intervening between the projection cl von-the said lever D andA the ,projection 7L on the lever'E. When the parts are in this -position, the valve will be full open. When a sudden and dangerous -increase in the speed of the engine causes the governor to depress the arm A, -thesleeve B with its wedges will be elevated to the position shown in Fig. 3, in which the thinner portion of the wedge c and the thicker portion of the wedge c intervene between the respective projections above mentioned. lWhen the parts are c in this. position, the valve is closed.

`As before remarked, a limited but positive vibrating motion is imparted to the lever D from any working -part of the en-y gine, the vibrationcontinuing as long as the engine is in motion. The vibration of this lever D is suoli, that its projections di and d, which we'term the strikers, neverj extend beyond certain points in the arcs of the circle in which they move, the distance between the limit of the movement of one striker and that of the other striker, measured over a continuation of the arc in which they move, being exactly the same as the distance between the perpendicular faces of the opposite wedges 0 and c', as measured over the same arc. l v

lThe appliances for operating the lever D should be such,rthat it should make at least three or four complete vibrations for every complete revolution of the engine, inasmuch as the rapidity and promptness in the movement of the valve F dependson the speed of the lever. This will be rendered more apparent hereafter.

Operation: Supposing the valveto be full open, as seen in Figs. l and 2, the governor having elevated the governor arm A, and consequently depressed the sleeve B, until the thickest portion of the wedge c intervenes between the striker Z and the projection 7L, and the thinnest portion of the wedge' c lbetween the striker CZ and the projection L. As long as the engine and governor remain at an uniform speed, the wedges will retain the above position, the strikers l and d during the vibration of the lever D only just touching the perpendicular sides of their respective wedges, without moving them or the valve F.

vthe perpendicular face of the wedge c, will `move it, together with the lever E, to an extent depending upon the thickness of the portion of the wedge presented to the striker. The opening f, therefore, will be closed toa proportional extent, and when the opening is thus partially closed, it will remain so until another variation in the speed of the governor takes place, which .will alter the position of the wedges, so

thatl the strikers will move the lever E and valve F in one direction or the other, ad1nit ting more or less steam to the engine, according to its requirements, thus tending to maintain it at an uniform speed; It will now be seen, that the opening and closing of the valve is not" effectedl directly from the governor as in vother engines, but by the ypower of the enginek itselfpall the aid required from the governor being to raise or lower the sleeve asthe speed of the engine varies, and thus to present such variable intervention to the action of the strikers, as shall move'the valve to an amount corresponding with that of the increase or diminution in the speed of the'engine.A The sudden submerging and emerging of steam boat propellers cause sudden diminutions or equally sudden increases in the speed of the engines, which require the most watchful attention of the engineers. The sudden increases especially have a most injurious, and, not infrequently, a most fatal effect on the engines. It is well known to practical and experienced engineers, that all the governors hitherto applied to marine engines have proved insufficient to remedy this evil, a sluggishnessin the action of the governor or the want of power sutlicient to operate the shut-off valves, being invariably the cause of this want of success. i

It is true, that an auxiliary steam cylinder, operated by a governor, has been used to some advantage,as an intermediate auxiliary between the governor and throttle valve, but this arrangement involves eX- pense, complication and uncertainty of action.

It will be at once seen, that the above described power attachment to governors must be unerring in its action, accurate litting of the appliances for transmitting the must be most sensitive in its action, for the tions Vof the wedges, and move the lever E slightest variation in the position of the wedges must be communicated to the valve.

As to rapidity of action, this, as before remarked, depends upon the speed, with which the lever D vibrates. This may be easily so arranged, that the valve will be operated before one fourth of a revolution of the engine has been accomplished, so that the tendency of the latter to run off, on the emerging of the propeller, is arrested before any injurious effects can take place.

It will be readily seen, that the connec tions with the engine for operating the lever D, those between the governor and wedges, and those for operating the valve must depend upon the particular class of engine to which our invention is applied, and to the position it is intended to occupy with regard to the engine. The invention itself also admits of several modifications, without departing from its main features.

1n Figs. et, 5 and 6, a modified form of our invention is illustrated. 1n this instance, the lever D, with its strikers (Z and 0l', is caused by the engine to vibrate on a permanent pin C, another lever E, with one arm prolonged, so as to connect with the valve, being also hung loose to th`e same pin. Two wedge-formed pieces c and c, connected together, are arranged to slide up and down on a projection on the pin C, the governor rod ai, attached to the arm A, controlling the vertical position of the wedges, one of which bears against the pin 7L, and the other against the pin 71.', said pins being attached to the arm E, at equal distances from its center. Any variation in the speed of the governor will be communicated to the wedges, the thicker or thinner portion of each wedge being presented to one or the other of the strikers as the governor varies, and the wedge that is struck operating on one of the pins 7L or 7L of the arm E, the movement of which actuates the valve, so that precisely the same result is obtained, as that accomplished by the first described modification.

Fig. l is a diagram, illustrating a third modification, in which the wedges c and c are secured to a lever E, which is connected to the valve, both wedges and lever vibrating loosely on a permanent pin C. The strikers Z and (Z project from an arm D, the end of which is hung to a pin on a slide H, to which a reciprocating motion of a determined length is imparted by the engine. The opposite end of the arm D is connected to the governor rod a', so that any variation in the vertical position of the latter must present the reciprocating strikers to different porand valve accordingly. This modification is precisely similar in principle to those above described, the only difference in its operation being, that the vertical position of the strikers is varied by the governor, instead of the wedges being altered, as in the two first described modifications.

1n some instances, the strikers may be attached to a spindle and the latter caused to revolve, so as to come in Contact with the inclined planes, when any movement of the governor takes place.

Having now described the construction and operation of our improved positive power attachment to governors, we wish it to be understood, that we do not desire to confine ourselves to the precise form or construction of the several parts or to any of the modifications described, as the parts may be considerably altered and other combinations and modifications substituted for those set forth, without departing from the main features of the invention. To also wish it to be understood, that we are aware that edges have been heretofore used in connection with governors, for tripping the valves and entirely cutting o the steam from the cylinders of steam engines.

Ve therefore limit our claim to, and desire to secure by Letters Patent,

Causing the positive power of the enOine to operate the throttle valve, by the employment of two vibrating, reciprocating or rotating strikers, actuated by any positive movement of the engine, in combination with two inclined planes, intervening between the said strikers and the valve or appliances connected therewith; any governor being so connected to the strikers or to the inclined planes, that the movement of the governor caused by any increase or diminution in the speed of the engine, shall change the position of the inclined planes in respect to the strikers, or that of the strikers in respect to the inclined planes, and that the latter may thereby be the intermediate means of regulating the extent of the opening of the valve, to suit the speed of the engine, while the actual movement of the valve is effected through one or the other of the strikers, by the power of the engine itself, as herein set forth.

In testimony whereof, we have signed our names to this specification in the presence of two subscribing witnesses.

W'M. YV. 1V. WOOD. HENRY HOVSON. Titnesses HENRY ODIORNE, HORACE SEE.

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