US368044A - Edwin j - Google Patents

Description

(No Model.) E. J. ARMSTRONG V GOVERNOR FOR STEAM ENGINES. No. 368.044. Patented Aug. 9, 1887.

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M Attorney,

UNITED STATES PATENT OFFICE,

EDWIN J. ARMSTRONG, OF PAINTED POST, NEW YORK, ASSIGNOR TO THE IVESTON ENGINE COMPANY, OF SAME PLACE.

GOVERNOR FOR STEAM-ENGINES.

SPECIFICATION forming part of Letters Patent No. 368,044, dated August 9, 1887.

Application filed April 30, 1887. Serial No. 236,685. (No model.)

To all whom it may concern.-

Be it known that I, EDWIN J. ARMSTRONG, a citizen of the United States, residing at Painted Post, in the county of Steuben and State of NewYork, have invented certain new and useful Improvements in Fly-Wheel Governors for Steam-Engines; and I do hereby defibcla're the following to be a full, clear, and exact description of the invention, such as will [0 enable others skilled in the art to which it appertains to make and use the same. I

This invention relates to that class of steamengine governors commonly called fly-wheel governors, such as have a laterallymovable eccentric surrounding the'crank-shaft of the engine and weights acting centrifugally in combination with a centripetally-acting spring to vary the position of the eccentric, and thus regulate the movement of the valve and produce a uniform speed in the engine.

It has been usual heretofore in this class of governors to vary the speed of the engine by sliding the weights alongtheir levers, but with entire disregard to the law governing their operation in so far as preserving the same degree of isochronism at all speeds is concerned. Thus when the levers carrying the weights extend directly in a straight line from their pivotal points to the centers of the weights and said weights are moved along said levers toward the pivotal points of thelevers, it is evident that the governing will be less close, for the reason that the movement of the weights in shifting the eccentric then bear a less proportion in distance from the center of the wheel to that which they hear when out to ward the end of the lever, or, in other words, the throw of the weights is lessened, but their distance from the center of the wheel is not. Now, starting with the wheel at rest and the weights at the extreme ends of the lovers, it is evident that when the speed of the wheel becomes high enough the weights will be thrown outwardly,overcoming the normal centripetal force of the spring; but as one end of the springis rigidly secured its retractile strength increases as the weight advances outwardly, and thus increases its centripetalforce, and as the diameter of the circle in which the weights travel is enlarged or becomes greater with the outward movement they consequently have greater centrifugal force with which to meet the increased centripetal force of the spring, and thus effect a balance.

It is found in practice to be necessary to have the centripetal force of the spring increase slightly faster than the centrifugal force of the weights, in order to prevent jumping or unsteady action of the governor. This, though necessary, is an evil, because the gov- 6o ernor, as the weights move outwardly, must obviously be rotated with greater speed. The difference between the speed required to start the weights in their outward movement and that required to maintain them in their extreme outward position is termed by engineers percentage of governor variation, and it is very desirable that this percentage be kept as low as possible. If,now,the weights be moved in a direct line toward the pivotal points of their levers,it is evident that the speed of the governor will have to be higher, by reason of the lessened or reduced leverage, to overcome the tension or resilience of the spring. It is also evident that, although havinga movement 7 through the same are of a circle, they yet do not have the same amount of movement in feet or inches, and consequently in their outward movement the centrifugal force does not increase as rapidly as when the weights are at the So extreme end of the levers. If, then, the centrifugal force does not increase as rapidly, owing to the reduced leverage or the lessened travel of the weight, it is plain that the necessary increase of centrifugal force must be obtained by 8 5 increased rapidity of rotation, which increases the percentage of variation of the governor to a pernicious extent. I overcome this diffi-' culty. by giving the weights a movement in a direction at such an angle to a line drawn 0 through the centers of the pivotal point and the weight as will bring the weights nearer the center of the wheel as their outward movement occasioned by their shortened leverage lessens, and thus preserve the same relation of 5 centrifugal to centripetal force in their various positions. By this means I preserve the same degree of isochronism through all the range of speed of which the governor is capable, which is the principal object of my invention.

In the accompanying drawing, forming a part of this specification, a governor embodying my invention is represented in side elcvation.

A. represents a ily-wheel suitably secured on the main or crank shaft B of an engine. An eccentric, C, surrounds the main shaft and is provided with a projecting arm, D, which is pivoted at its end to one of the spokes of the wheel near its rim, thus suspending the eccentric so that it may swing or have a free lateral movement.

From the opposite side of the eccentric extends an arm, E, having its end formed or shaped liken foot-that is, with two points of diiTerent lengths, which may be called, for the purposes of this specification, the heel b, and toe a. These arms 1) and E are cast with the projecting eccentric-ring 0, though, if desired, they may be cast separately and rigidly secured thereto. Two pins, 1/ a, are secured in the heel and toe I) a, respectively, and project laterally therefrom, or toward the wheel A. To the pin 1) one end of a flat spring, F, is fastened, its other end being rigidly secured to the rim of the wheel. A lever, Gr, having two oppositely-projecting wings, d e, is pivotally secured at f to one of the spokes of the wheel adjacent its rim. The wing d is somewhat shorter than wing c and has its end curved forward and projects behind thetoe (0 of arm E, and there comes in contact with the pin a, secured in said toe. The wing c is of greater length than wing d and terminates at a point about midway between the pivotal points of lovers G and H, the end of said wing being slightly enlarged at its lower side and of rounded or curved form.

To a spoke adjacent the end of wing c, I pivot a lever, II, having a wing, 71, projecting toward lever G and similar lo wing 0, excepting that its curve is reverse to the curve of said wing c, and which is also provided with a rounded end or ii p which projects under the end of wing 0, and when at rest its normal p0 sition is against the point of asuitablc projection, M, extending from the rim of the wheel, the projection shown in this instance being also the balance-plate, which is drawn to a point for the purpose named.

The levers G and II are slightly enlarged at or about their middle portion to one side of their pivotal points and a screw-threaded perforation formed therein, in which a screwthreaded rod, L-one in each perf0ration-is inserted, the ends of said rods carrying suitable weights, N, which are either cast thereon or rigidly secured thereto, as shown in the drawing; but they may, if desired, be adj ustable on the rods and the rods rigidly secured to the arms. As clearly shown in the drawing, these rods L are set in the levers G H or project therefrom at such an. angle relative to each other and the levers that as the rods are screwed into the lovers or the weights moved along the rods toward the levers, if arigid rod and adjustable weight are employed, the weights will be brought nearer the center of the wheel, so that the relative degree of centrifugal force as the weights are thrown outward will be substantially the same as the increasing centripetal force of the spring, which, as above explained, is necessary to the various speeds to which the governor may be ad justed.

It will be noticed. that with this construction of a governor the bearings or wearing points of all the parts are normally under strain, each in some particular directiomwhich direction does not materially change during the operation of the governor, thus preventing any bad effects from lost motion which may be produced from the natural wear of the parts. 7

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is

1. In an automatic governor i'or steam-engines, the combination, with a laterally-movable pivoted eccentric and a spring, of pivoted levers having projecting wings, one of which is in contact with the eccentric, and wei hts secured to said levers adjustable at an angle between the pivotal points of the levers and the center of the wheel, substantially as described.

2. In an automatic governor for steam-engincs, the combination, with a laterally-movable pivoted eccentric and a spring secured to said eccentric, of a pair of winged levers pivoted to the wheel and having their wings in contact, and one of said wings in contact with the eccentric, and rods provided with suitable weights adjustably secured to said levers at an angle between their pivotal points and the center of the wheel, whereby the adjustment of the weights toward the levers will bring them nearer the center of the wheel, as set forth.

3. In a fly-wheel governor, pivoted levers having adj ustable weights secured thereto at an angle trending toward the center of said wheel, whereby the shortening of their leverage will throw them nearer the center of the wheel, substantially as and for the purpose set forth.

4. The combination, in a fiy-wheel governor, of a suitable laterally-movable eccentric, a spring attached thereto, a double-winged pivoted lever having one of its wings connected with said eccentric, a single-winged pivoted lever connected. with said double-winged lever, and adjustable weights secured to said levers at an angle, whereby said weights, when their centrifugal travel is shortened, are brought in closer proximity to the center of the wheel, substantially as set forth.

5. A lly-wheel governor comprising a wheel, A, a spring, F, having one end rigidly secured to said wheel, a pivoted laterally-movable ee- IIO centric having arms D E, the latter having the In testimony whereof I affix my signature in heel and toe b aand pins 1) a secured thereto, presence of two witnesses. a pivoted lever, G, having the Wings (1 e, the pivoted lever H; having the wing h, the rods v EDWIN ARMSTRONG 5 L, provided with weights N, secured to said Witnesses:

levers at an angle, and a suitable projection, PHILIP MAURO, M, substantially as described. 0. J. HEDRIOK.

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