US2873961A - Centrifugal governor construction - Google Patents

Description

17, 1959 F. HEINZMANN csnmvucm. GOVERNOR CONSTRUCTION 2 Sheets-Sheet 1 Filed July 5, 1957 Q 0 E W I Feb. 17, 1959 F. HEINZMANN 2,873,961

CENTRIFUGAL GOVERNOR CONSTRUCTION 1 Filed July 5, 1957 2 Sheets-Sheet 2 United States Patent CENTRIFUGAL GOVERNOR CONSTRUCTION Fritz Heinzmann, Albershausen, Kreis Goppingen,

Germany Application July 5, 1957, Serial N 0. 670,181 Claims priority, application Germany July 12, 1956 6 Claims. (Cl. 264-15) This invention relates to an improved centrifugal governor construction.

The invention more particularly relates to an improved construction for a centrifugal governor having a rotatable governor body, a pair of opposed flyweights pivotally connected to the governor body for pivoting outwardly by centrifugal force upon rotation of the body, inwardly extending lever arms connected to the flyweights, a control member substantially eoaxially positioned with respect to the axis of rotation of the governor body and a transverse rod connecting the lever arms and the control member for axial movement of the control member upon pivoting of the flyweights with the lever arms. A governor of this construction is for example disclosed in United States Patent 2,807,455 dated Sept. 24, 1957.

As the lever arms connected to the flyweights swing in an are as the flyweights pivot, the openings therethrough for the rod which moves the control member cannot be maintained in exact alignment at all positions of movement and the rod must be able to move transversely in the openings of the lever arm or arms of at least one of the flyweights. conventionally, the rod is a cylindrically shaped rod and fits in a correspondingly shaped cylindrical hole in the lever arm or arms of one of the flyweights. Therefore, upon actuation of the governor the rod will describe an arcuate path with the lever arm of this flyweight. Slots which are transverse to the axis of rotation of the governor are defined through the lever arm or arms of the other flyweight and through the control member. The rod extends through these transverse slots so that as the governor is actuated and the rod describes its arcuate path, the rod slides in the slots. The points of contact where the rod slides along these slots are relatively quickly worn in operation which results in a certain amount of free play so that backlash occurs at each change in movement. This reduces the reliability of the governor in operation and causes the governor to hunt.

One object of this invention is a novel construction which overcomes this disadvantage. This and still further objects will become apparent in the following description read in conjunction with the drawings in which:

Fig. l is a perspective view of an embodiment of a centrifugal governor in accordance with the invention,

Fig. 2 is a side elevation partially in vertical section of the embodiment shown in Fig. 1,

Fig. 3 is a cross section through the rod of Fig. 1 showing the connection of the lever arms and bushing to the rod.

Fig. 4 is a perspective view of Fig. 3,

Fig. 5 is a section through one of the lever arms of Fig. 3,

Fig. 6 is a section through the other of the lever arms of Fig. 3.

Fig. 7 is a side elevation partially in section of the upper half of a further embodiment of a governor in accordance with the invention, and

2 Fig. 8 is a section through the embodiment shown in Fig. 7.

In accordance with the invention, the transverse rodwhich connects the lever arms and control member for movement is a substantially cylindrical rod having at least one and preferably two opposed substantially parallel flattened faces. The rod engages in a substantially cylindrical hole having a diameter corresponding to the cylindrical diameter of the rod defined in the lever arm or arms of one of the flyweights and engages in a slot shaped opening having a width corresponding to the diameter of the flattened portion of the rod and a length greater than the cylindrical diameter of the rod defined in the lever arm or arms of the other of the flyweights.

The control member preferably defines a slot shaped opening therethrough extending transverse to the axis of rotation of the governor body. A flattened bushing is positioned in the slot shaped opening for sliding in a direction transverse to the axis of rotation. The bushing defines a cylindrical opening corresponding to the cylindrical diameter of the rod and the rod extends through this opening. H

In accordance with another embodiment of lite invention, the lever arms are so constructed that their length with respect to the flyweights may be freely varied during operation, as for example, by having them slidably mounted in a corresponding bore in the rod connecting lever arm and the control member for movement is cylindrical in shape and the openings through the lever arms and the control member through which the rod extends has a corresponding cylindrical shape. During operation as the flyweights move out and in, the length of the lever arms vary so that the same may describe a straight line path rather than an arcuate path so that no transverse sliding movement of the rod with respect to any of these parts need be provided for.

Referring to the embodiment shown in Figs. 16 of the drawing, the governor has a rotatable governor body 2 on which two opposed flyweights 1 and 1a are pivotally connected by means of the pivot pins 3 and 3a respectively. As the governor is rotated, the centrifugal force will cause the flyweights 1 and la to pivot outwardly away from each other about the pivot pins 3. The flyweight 1 has the inwardly extending lever arms 4 connected thereto and the flyweight 1a has the inwardly extending lever arms 5 connected thereto. As shown these lever arms are formed as an integral part of their respective flyweights. Slot shaped openings 6 are defined in the ends of the lever arms 4 and cylindrical openings 7 are defined in the ends of the lever arms 5. The central portion of the governor body 2 is provided with a bore 8 which extends coaxial to the axis of rotation. A transverse rod 9 of cylindrical shape with two opposed parallel flattened faces extends through the openings 6 and 7 in the lever arms 4 and 5. The length of the slotted openings 6 in the transverse direction to the axis of rotation of the governor is greater than the cylindrical diameter of the rod 9 and the width of the slotted opening 6 corresponds to the diameter of the flattened portion of the rod 9 so that the rod 9 may slide along the length of the slot shaped opening but may not move in the slot shaped opening in the direction of its flattened faces. The openings 7 have a cylindrical shape with a diameter corresponding to the cylindrical diameter of the rod 9 so that the rod 9 may rotate therein but may not move transversely therein.

A control member in the form of a control rod 10 is slidably positioned in the bore 8 so that the same is eoaxially positioned with respect to the axis of rotation to the governor and may slide eoaxially with respect to this axis. A slot shaped opening 11 is defined transflyweights. The p versely through the control member 10. A flattened bushing 12 is slidably positioned in the slot shaped opening for sliding in a direction transverse to the axis of rotation of the governor. The bushing has a central cylindrical opening corresponding in diameter to the cylindrical diameter of the rod 9 and the rod 9.extends therethrough.

The flyweight 1 has an opening therethrough extending transverse to the axis of rotation and the fiyweight 1a has a corresponding opening 13a. A stay bolt 14 is connected to the governor body 2 and extends through the opening 13 in a direction transverse to the axis of rotation. A similar stay bolt 14a is connected to opposite side of the governor body 2 and extends through v the opening 13a. The coil spring 15 and the coil spring 16 coaxially positioned within the coil spring 15 surround the stay bolt 14. Corresponding springs 15a and 16a are provided on stay bolt 14a. The inner ends of the springs 15 and 16 press against an annular spring bushing 17. A corresponding bushing not shown is provided for the springs 15a and 1611. From the annular spring bushings two arms extend in opposite directions, these arms being provided with knife edges. In Fig. 2, the arm 18a is shown. The arms provided with knife edges rest in correspondingly wedge shaped slots in the fiyweights. The springs 15 and 15 are maintained in place and held for compression by means of the nut 19 screwed on the end of the stay bolt 14 and a corresponding nut 19a is provided on the stay bolt 14a.

The rod 9 is maintained in place by means of the pins 20 extending through the openings 6 and 7 of the outermost lever arms 4 and passed the ends of the rod 9 thus preventing the rod from axially slipping out of the governor.

In operation, the governor is caused to rotate about its axis of rotation by a prime mover, as for example, an internal combustion engine. The control member 10 is connected by means of a suitable linkage to a control element, as for example, the distributor of the engine. As the governor is caused to rotate, the centrifugal force forces the fiyweights 1 and 1a outwardly against the force of the springs 15, 16, a, 16a causing the springs to compress. The outward pivoting of the fiyweights causes a corresponding movement of the lever arms 4 and 5. As the lever arms 5 move, the same describe an areuate path with the center of the are being the pivot pins 3a. The rod 9a is carried along with these lever arms in this arcuate path. The lever arms 4 describe a corresponding opposite arcuate path and the same forces the rod 9 to move in the same direction along the axis of rotation of the governor but the rod 9 slides transversely along the slot shaped openings 6 to compensate for the variation in alignment between the holes 5 and 6. As the lever arm 4 moves the same will of course cause the rod 9 to rotate as the same is held firm from rotary motion in the slotted openings 6. The rod 9 will rotate in the central bore of the bushing 12 and the transverse movement of the rod 9 caused by its arcuate path will be taken up by sliding movement of the bushing 12 in the slotted'openings 11.

As the fiyweights move out, the control member 10 is therefore moved axially effecting the control function. Compressive force of the springs 15, 16, 15a and 16a is taken up on the knife edges of the arms corresponding to the arm 18a connected to the spring bushings corresponding to the bushing 17.

In all positions of movement a firm contacting between the rod 9 and the parts connected for motion therewith is effected. The conventionally occurring points of wear at which wear rapidly occurred are eliminated so that the free play backlash and errors in operation associated with this wear are eliminated.

The construction of the governor as shown in Figs. 7 and 8 corresponds to that shown in the previous figures except that the lever arms 24 and which correspond to the lever arms 4 and 5 on previous embodiments, have a portion 21 of cylindrical shape which slidably fits into a corresponding cylindrical bore 22 in the fiyweights. The openings which correspond [0 the openings 6 and 7 in the ends of the lever arm are all cylindrical as is the opening through the control member 10 to which the rod 23 which corresponds to the rod 9 extends. The cylindrical shape through the ends of these lever arms and through the member correspond in diameter to the diameter of the rod 23 which is also cylindrical in shape. In operation, as the fiyweights are forced out by centrifugal force, the length of the lever arms 24 and 25 with respect to the fiyweights will vary by the cylindrical portions 21 sliding in or out of the cylindrical bores 22 so that the ends of the lever arms and the rod 23 may de scribe a straight line path along the axis of rotation of the governor and provisions need not be provided for transverse movement of the rod in the openings.

While the invention has been described indetail with reference to specific embodiment shown, various changes and modifications will become apparent to the skilled artisan which fall within the spirit of the invention and scope of the appended claims.

I claim:

1. In a centrifugal governor having a rotatable governor body, a pair of opposed fiyweights pivotally connected to the governor body for pivoting outwardly by centrifugal force upon rotation of the body, inwardly extending lever arms connected to said fiyweights, a control member substantially coaxially positioned with respect to the axis of rotation of said governor body and a transverse rod connecting said lever arms and said control member for axial movement of said control member upon pivoting of said fiyweights with said lever arms. the improvement which comprises said transverse rod being a substantially cylindrical rod having at least one flattened face, said rod engaging in a substantially cylindrical hole having a diameter substantially corresponding to the cylindrical diameter of said rod and defined in the lever arm of one of said fiyweights also and engaging in a slot shaped opening having a width corresponding to the diameter of the flattened portion of said rod and a length greater than the cylindrical diameter ofsaid rod said slot being defined in the lever arm of the other of said fiyweights.

2. Improvement according to claim 1 in which said control member defines a slot shaped opening therethrough extending transverse to the axis of rotation of said body, and including a flattened bushing slidably positioned in said slot shaped opening for sliding in a direction transverse to said axis of rotation, said bushing defining a cylindrical opening corresponding in diameter to the cylindrical diameter of said rod, with said rod extending therethrough.

3. Improvement according to claim 2 in which each said fiyweight has two lever arms connected thereto with corresponding openings.

4. Improvement according to claim 3 in which said transverse rod has two opposed substantially parallel flattened faces.

5. Improvement according to claim 1 inwhich said transverse rod has two opposed substantially parallel flattened faces.

6. Improvement accordingto claim 1 in which each said flyweight has two lever arms with corresponding openings defined therethrough.

References Cited in the file of this patent UNITED STATES PATENTS 604,798 Smith et a1. May 31, 1898 1,130,326 Palmer Mar. 2, 1915 1,484,145 Massey Feb. 19, 1924 1,576,933 Romeyn Mar. 16, 1926 FOREIGN PATENTS 732.168 Great Britain June 22, 1955

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