US2646978A - Centrifugal governor having weights successively supported by spaced pivots - Google Patents

Description

1min.

July 28, 1953 c, BARNES 2,646,978

CENTRIFUGAL GOVERNOR HAVING WEIGHTS SUCCESSIVELY SUPPORTED BY SPACED PIVOT-S I Filed 001;. 6, 1952 2 Sheets-Sheet l IN VEN TOR.

R. C. BARNES July 28, 1953 CENTRIFUGAL GOVERNOR HAVING WEIGHTS SUCCESSIVELY I SUPPORTED BY SPACED PIVOTS 2 Sheets-Sheet 2 Filed Oct. 6, 1952 Y INVENTOR. fism/d mm BY ATTORNEY Patented July 28, 1953 CENTBIFUGAL GOVERNOR HAVING WEIGHTS SUCCESSIVELY SUPPORT- ED BY SPACE!) PIVOTS Randolph C. Barnes, Peoria, 111., assignor to Caterpillar Tractor 00., Peoria, 111., a corporation of California Application October 6, 1952, Serial No. 313,323

3 Claims. 1

The present invention relates to centrifugal type engine governors and particularly to a type of governor adapted for automotive use in which it is desirable to reduce the fiyweight effect when the engine is operating at a high speed.

In governors of this type, it has been common practice to employ two sets of fiyweights to obtain satisfactory governing throughout the entire speed range of the engine. A large set of flyweights having two pivots or fulcrum points speeds, and a second smaller set comes into operation as the engine attains higher speed.

It is the object of the present invention to provide an engine governor of the centrifugal type with a single set of fiyweights capable of operation throughout the entire speed range of the engine by exerting a relatively small force as they are rotated at high speed. A furthe object of the invention is to provide a governor with fiyweights having two pivots or fulcrum points on each weight spaced different distances from the heavy end of the fiyweight and coming into operative position selectively during different operative speeds of the engine. Further and more specific objects and advantages of the invention are made apparent in the following specification wherein a preferred form of the invention is described in detail by reference to the accompanying drawings.

In the drawings:

Fig. 1 is a view in side elevation of a governor embodying the present invention with parts shown in section to expose details of construction and with the fiyweights illustrated in the position assumed in the low speed operating range,

Fig. 2 is a fragmentary view illustrating one of the flyweights in the position assumed when the engine is operating in its high speed range,

Fig. 3 is a perspective View of the flyweight carrier, shown in Fig. l, with some of the parts associated therewith, and

Fig. 4 is a perspective view of one fiyweight with its supporting shaft.

Referring first to Fig. 1 of the drawings, a conventional governor assembly is illustrated as comprising a governor shaft supported for rotation in bearings, one of which is illustrated at H. The shaft ID is driven at speeds corresponding to engine speeds through a gear train, not shown, ending with a gear l2 secured by any suitable means against rotation on the shaft l0. Secured to the gear 12 and preferably formed as an integral part thereof is a flyweight carrier l3, the form of which is most clearly illustrated in Fig. 3.

A pair of fiyweights M, as shown in Fig. 4, is supported by means presently to be described in detail for rocking movement in the carrier [3, and each flyweight has a weighted end l5 and a finger Is at its opposite end adapted to bear against a collar ll which is supported for sliding movement upon and for rotation about the shaft The operation of the governor is conventional to the extent that upon the event of high speed, the fiyweights tend to move outwardly so that the fingers l6 urge the collar ll to the right, as viewed in Fig. 1, to bear against a roller I8 carried by a lever is. The lever 19 is supported for rockin movement on a shaft 20 and carries a crank arm M to which is anchored one end of a governor spring assembly, generally indicated at 22. The end of the lever [B is connected as by a link 23 to an engine speed control device such, for example, as a rack bar which adjusts the volumetric output of fuel feed pumps or the like, a portion of the rack bar being illustrated at 24. The spring assembly 22 opposes the action of the flyweights in their tendency to shut down the engine by moving the rack bar 24 toward the right.

In the present case, the spring assembly comprises a low rate spring 25 effective for slow speed operation and a spring 26 of higher rate which becomes effective when the engine is operating in its higher speed range. This is accomplished by providing a rod 21 slidable through the upper spring anchor 28 of the low rate spring and having a head 29 thereon engageable with the spring anchor when the spring has been extended to a predetermined limit. The same spring anchor 28 anchors the lower end of the high rate spring 26 so that upon engagement of the head 29 therewith, the high rate spring is placed in tension and becomes effective. The upper anchor 30 of the high rate spring is pivotally connected with a manual control mechanism of conventional type through a lever, partly shown at 3|, and designed to vary the adjusted tension of the spring assembly in order to control the operating speed of the engine.

Each of the flyweights I4, as best illustrated in Fig. 4, is provided with a pivot shaft 32 projecting from opposite sides of the fiyweight and having its projecting ends shaped to provide spaced fulcrum points 33 and 34. These fulcrum points are in efiect long knife edge or low friction bearings and are arranged to bear in V-shaped recesses 35 and 36 (see Fig. 3), respectively, depending upon the position of the fiyweights. The

bearing points for the fulcrums 33 and 34 are formed adjacent the edges of the fiyweight carrier I3, the central portion of which is recessed or cut-away, as shown, to provide clearance for the rocking movement of the flyweights. In operation, the centrifugal force set up by the tendency of the fiyweights to separate or swing outwardly retains the fulcrum points or edges 33 and 34 in their proper bearing positions, and in order to prevent the flyweights from falling out of the carrier when the engine is at rest, a bar 38 is secured as by cap screws 39 to each side of the carrier, one such bar being shown in Fig. 3. This bar is suitably recessed, as illustrated at 40, to provide sufficient space for free rocking movement of the shafts 32 which support the flyweights. Due to this construction the flyweights move with a minimum of frictional interference. The low speed operating position of the flyweights is illustrated in Fig. 1 of the drawings wherein the fulcrum point 34 bears in the notch 36 and since the fulcrum point 34 is spaced a greater distance from the weighted end [5 of the fiyweight, the effect of the weight is greater as though heavy weights were being employed. As the engine attains higher speed and the weights swing outwardly, as illustrated in Fig. 2, the fulcrum point or edge 33 comes to bear in its notch 35 and the edge. 34 is moved out of bearing contact. Consequently, the fulcrum point now in effect is closer to the weighted end of the flyweight and the change in the leverage has the same effect as though lighter weights were in use.

With the construction herein described, a single pair of governor flyweights serves to produce the effect previously obtained with two sets of fiyweights operating selectively during different speed ranges of engine operation.

I claim:

1. In a centrifugal type engine governor in which a set of fiyweights acts in opposition to a governor spring assembly, two fulcrum points associated with each fiyweight and spaced different distances from the weighted end thereof, a carrier for the flyweights providing seats against which said points can bear, and means supporting the fiyweights for free movement so that the fulcrum points may bear selectively on their respective seats during different speed ranges of engine operation.

2. A fiyweight for a centrifugal type engine governor having a supporting shaft permitting it to rock under influence of centrifugal force, said shaft being formed with spaced bearing edges, and a carrier for the fiyweight providing spaced notches to receive said edges selectively as engine speed changes whereby the fulcrum point of fiyweight action will change between low speed operation and high speed operation.

3. In a centrifugal type engine governor in which a set of flyweights acts in opposition to a governor spring assembly, a carrier supporting the fiyweights for rocking motion, and two knife edge bearings between each fiyweight and the carrier providing fulcrum points at different distances from the weighted end of the fiyweight, whereby the flyweights will rock about different fulcrums under different speed conditions.

RANDOLPH C. BARNES.

No references cited.

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