This governor was designed in 188:1. and has been applied to a number of CTIalFR'S with unbalanced as well as balanced valves. A small shaft //is junnialed in the hub of the fly-wheel. and is parallel to the main shaft. The eccentric. whose center is at 1), one end of the shaft B. and the cross-arm d to the other. The center• of the eccentric may this move about li, across the shaft. and produee the variable valve-motion. Eaeh end of the eross-arm d nected by a link to an arm e. pivoted at P. The tlying-weight W fixed to the arm 0. also pivoted at P, tends to move outward as the speed increases. is resisted by a weight E acting (am the arm b. also pivoted at P. whirl! 1110VeS inward when moves outward. The spring S. whose• axis is radial, also acts on arm b, and assists the weight E to urge It in ward. The calve resist ;Mee als,i assists the weight E. The arms a 1.) r nil formed in one piece. The weights II' stud E and spring N move as nearly as possible upon radii from the center of rotation. For Ilse purpose of reducing the friction to a minimum. the pivot P, which sustains the greatest strain, and Ill(' lit the vials of arms b, are made in the form of knife-edges of hardened steel.
They require lilt le or no oil. and are inclosed so as not to gather dust. The joints of the links suPPurt fit I iv strain. and are usually made simple pin connections. eccentric• being mounted on the B., which has a long bearing in the hub of the lly-wheel, requires little force to move it. The shaft B may, besides, be oiled while the engine is running, by means of a small pipe extending from the center of the main shaft to the middle of shaft B, so that the friction here is also reduced to a very small amount. This governor is readily
adapted to run in either direction. The spring has only to take up the difference of centrif ugal force of the weight W in its inner and outer positions, instead of the whole of that force, as in most governors. The spring may therefore be small and short, and still not be strained to such an extent as to fatigue the metal. A common compression-spring, such as is in use under cars, has been employed, and found simple and effective. If a spring breaks, the en gine stops. The initial tension of the spring. which is what supplies the greater part of the centripetal force in most governors, is here replaced by the centrifugal force of the weight E, which force is practically constant within the range of speed variation. A variation of speed of less than 1 per cent between no load and 0.7 cut-off may be readily obtained in practice, and this regulation can be maintained during long-continued runs. When this governor is applied to center-crank engines with valve connections outside of the fly-wheel the eccentric can be dispensed with, and replaced by a wrist-pin D' formed on the end of an arm extending from the cross-arm d, as shown in dotted lines to the left of Fig. 3.
The Rice Aidomatic Engine-Governor is shown in Fig. 4. It consists of two balls hung on pivots, and held in equilibrium against centrifugal force by two elliptic springs, whose tension may be increased or diminished by the tension-bolt which connects them. The balls are con nected to a lever, which in its turn is connected with the eccentric through the hollow crank-pin. The balls are cast hollow, and may be loaded with shot. (See ENGINES,