US2845821A - Switch operating mechanism - Google Patents

Description

E. J. DE NOYERS SWITCH OPERATING MECHANISM Aug. 5, 1958' 2 Sheets-Sheetl Filed May 29. 1957 5, 1958 E. J. DE NOYERS SWITCH OPERATING MECHANISM 2 Sheets-Sheet 2 Filed May 29, 1957 Emil J. Us No em, I?

4 .H a Y I United States Patent 2,845,821 SWITCH OPERATING MECHANISM Emil J. De Noyers, Pittsfield, Mass., assignor to General Electric Company, a corporation of New York Application May 29, 1957, SerialNo. 662,462

6 Claims. (Cl. 74-804) This invention relates to an electrical switch operating mechanism, and more in particular to an improved mechanism for rotating the shaft of a tap switch, the mechanism including indicia for indicating the position of the tap switch, and means for locking the switch shaft.

One form of tap switch operating mechanism is comprised of an operating shaft adapted to rotate the contacts of the switch. The operating shaft has an eccentric portion'adjacent the end controlled by an operator, and a disc-shaped cam is mounted for free rotation on the eccentric portion of the shaft. An annular plate is provided surrounding the shaft, the plate being mounted in a fixed position, for example, to a mounting base member adapted to be bolted to the switch or apparatus contain ing the switch. The annular plate has a crenelated radially inner edge, and a pair of pins mounted on the discshaped cam engage the crenelations of the annular plate so that angular displacement of the shaft effects a lesser angular displacement of the cam.

A hub is rigidly afiixed to the end of the shaft controlled by an operator, and the hub has a bifurcated portion in which a folding handle is pivoted. The discshaped cam has an aperture extending therethrough to expose to view a portion of the face of the annular plate, and indicia on the plate visible through the aperture indicates the tap position of the switch.

The folding handle comprises a link pivoted on one end in the bifurcated portion of the hub, and pivoted on the other end to one arm of an L-shaped member. The other arm of the L-shaped member comprises a crank handle member for an operator to grasp and may have a circular cross section. The link and arms of the fold ing handle have such a dimension that, when folded, the crank handle member engages the aperture in the disc-shaped cam to lock the operating shaft against rotation. Aside from serving to lock the shaft, the folding handle i provided in order that a cover bolted over the handle may have minimum dimensions.

While the above-described operating mechanism has been found to operate satisfactorily, the limitation of the eifective crank arm of the operating handle dictated by the necessity for providing a minimum size for the cover, has limited the size of tap switch upon which the mechanism may be employed, With increases in the size of the tap switch, the torque necessary on the operating shaft to operate the tap switch also increases, and thus with the previously employed tap switch sufficient torque could not be applied to the shaft by an operator to operate a large switch. As a result, when higher tap changing torque was required, it has been necessary in the past to provide more bulky and expensive handwheel drive mechanisms that generally have exposed rotating parts that cannot economically be provided with covers.

It is therefore an object to provide a tap switch operating mechanism characterized by enabling an operator to. develop substantially greater torque on the operating shaft than was possible with the previously described ICE folding handle mechanism, and yet retain the advantages of compactness and a minimum size protection cover.

Briefly stated, in accordance with the one aspect of my invention, I provide a switch operating mechanism comprising an operating shaft having an eccentric means thereon. A disc cam is provided freely rotatable on the eccentric means on the shaft. An annular plate means is rigidly aflixed as to a base member, the annular plate means surrounding the shaft and having internal crenelations. A pair of pins extending from the cam are arranged to engage crenelations such that angular displacement of the shaft effects a predetermined lesser angular displacement of the cam. A hub is provided on the end of the shaft, and a pair of linearly extensible handles are pivoted to the hub, for example, in diametrically opposed bifurcations provided in the hub. Means are provided for locking the shaft comprising a pair of notches in the cam, and a projection on each of the handles. The projections are preferably on the ends of the handles, and are positioned to engage the notches in the cam when the handles are pivoted to positions substantially parallel to the shaft.

While the specification concludes with claims particularly pointing out and distinctly claiming the subject matter which I regard as my invention, it is believed that the invention will be better understood from the following description taken in connection with the accompanying drawings.

In the drawings:

Fig. 1 is a partial cross-sectional view of a shaft operating mechanism according to my invention,

Fig.2 is a partially cross-sectional view of the switch operating mechanism of Fig.1 taken along the lines 2-2 of Fig. 1,

Fig. 3 is a partially cross-sectional view of the switch operating mechanism of Fig. 1 taken along the lines 3-3 of Fig. 1,

Fig. 4 is an end view of the switch operating mechanism of Fig. 1,

Fig. 5 is an exploded view of the operating components of the switch operatingmechanism of Fig. 1,

Fig. 6 is a perspective cross-sectional view of a portion of the switch operating mechanism of Fig. 1, and

Fig. 7 is a perspective view of the hub member of the switch operating mechanism of Fig. 1.

Referring now to the drawings, and more in particular to Fig. 1, therein is illustrated a switch operating mechanism comprising an operating shaft 10 adapted, for example, to rotate the contacts of an electric switch. The shaft 10 extends through a mounting base member 11, and the end 12 (Fig. 2) of the shaft controlled by an operator has an eccentric portion 13. A hub member 15 (Figs. 1 and 2) is pinned or otherwise rigidly mounted on theend 12 of the shaft. The hub member has an eccentric portion 16 extending away from the end 12 of the shaft, and an annular disc-shaped cam 17 is mounted for free rotation on the eccentric portion 16 of the hub. The eccentric portions on the shaft and hub complement each other in order to economically achieve a desired eccentricity, and it will be obvious that it is not necessary functionally for each of these members to have eccentric portions. Thus, for example, if the desired eccentricity is obtainable by the eccentric portion of the shaft, the disc cam may be mounted on the eccentric portion of the shaft and the eccentric portion of the hub may be omitted. This may, however, require either an increase in diameter of the shaft or an offset portion on the shaft. Similarly, if the eccentric portion of the shaft is omitted, it may be necessary to increase the size of the hub to obtain the desired eccentric motion. 7

A pair of extensible handles 20, which may be more clearly seen in Fig. 2, are pivoted to the hub 15 the pivotal mounting enabling the handles to assume positions either parallel or normal to the shaft 10, and a removable cover 21 (shown in phantom in Figure 1) is provided that may be bolted to the base member 11 over the handles when the handles are pivoted to a position parallel to the shaft.

Referring again to Fig. 1, an annular plate 25 is mounted in a fixed position on the base member 11 and surrounding the shaft 10. The plate, which may be more clearly seen in Figs. 3 and 5, is provided with crenelations 26 on the radially inner edge. A pair of pins 27 are provided extending from one face of the disc cam (Figs. 1 and 3), and these cams engage the crenelations of annular plate 25 in the well known manner such that angular displacement of the shaft 10 and hub 15 results in a lesser angular displacement of the disc cam.

Referring now to Figs. 4, and 6, an aperture or notch 30 is provided extending through the disc cam, and indicia are provided on the face of the plate 25 visible through the aperture 30 to indicate the position ofthe tap switch.

The hub 15, which may' be more clearly seen in Fig. 7, has a pair of substantially diametrically opposed bifurcations 31, and the extensible handles are pivoted in the bifurcations 31 as shown most clearly in Figs. 2, 5 and 6 so that the handles may assume positions parallel to the shaft or in planes normal to the shaft 10. The handles 20 may be comprised of links 35 having one end 36 pivoted in the bifurcations of the hub. The links 35 have axially extending slots 37, and tubular handles 38 axially slidable over the links 35 have pins 39 extending into the slots 37 to limit the extension of the tubular handles. The ends 36 of the links are 'of such a length that when the handles 20 are parallel to the shaft .the ends 36 extend beyond the face of the hub and engage notches or grooves 40 in the adjacent face of the disc cam 17.

While the bifurcations of the hub are diametrically opposed, it will be noted in Figs. 4, 5 and 7 that they-are disposed so that the handles are parallel but not coaxial when they are pivoted to be in a plane normal to the shaft. Thus, as illustrated in the drawings, the axis of one of the handles may extend through the axis of the eccentric portion of the shaft 10, while the axis of the other handle may be skewed with respect to the axis of the eccentric portion of the shaft. This relative displacement of the axes of the handles has been provided in order to prevent locking of the shaft at other than full tap positions, as will be explained in more detail in the following paragraphs.

In the normal operating position of the switch, the tubular portions of the extensible handles 20 are slid over the link portions as far as possible so thatthe handles have minimum length, and the handles are pivoted to positions parallel to the shaft (as illustrated by the upper handle of Fig. 2), and the cover 21 is bolted to the base 11 holding the handles in this position. When the handles are thus pivoted, their ends 36 engage the notches 40 to prevent relative angular movement between the hub and disc cam. Since the pins of the disc cam engage the crenelations of the fixed annular plate 25, the disc cam may rotate only if it has an eccentric motion, and thus, preventing motion between the hub and disc cam serves to lock the operating shaft against rotation. Since the handles 20 are axially displaced, they cannot be pivoted parallel to the shaft unless their ends are adjacent the correct notch of the disc cam, and therefore the shaft cannot be locked in an incorrect position.

When it is desired to change taps with a switch controlled by the mechanism previously disclosed, the cover 21 is first removed, the handles are pivoted to positions in a plane normal to the shaft 10 (as the lower handle in Fig. 2), and the tubular portions are slid on the link portions to obtain the maximum handle extension. Then the'hub' is turned by the handles until the desired tap posi- 4 tion is indicated by the indicia on plate 25 visible through aperture 30 of disc cam 17.

With the arrangement of my invention, the torque rating for the drive mechanism has been increased from 16 foot lbs. of the previously described folding handle mechanism to 50 foot lbs., and the increase in torque rating has been obtained Without increase in the dimensions of the mechanism. The increase in torque rating arises from the fact that an operator may employ two hands to turn the shaft, whereas it was only feasible to employ one hand to operate the crank of the folding handle mechanism, and also because the force applied by the operator to the extensible handles is all directed normal to the moment arm, whereas in the folding handle mechanism a component of the applied force tends to twist the crank arm about its own axis.

It will be understood, of course, that, while the form of my invention herein shown and described constitutes thepreferred embodiment of the invention it is notintended herein to illustrate all of the equivalent forms or ramifications thereof. ,It will also be understood that the words used are words of description rather than of limitation, and that various changes may be made without departing from the spirit or scope of the invention herein disclosed, and it is aimed in the appended claims to. cover allsuch changes asfall within the true spirit and scope of the invention.

What I claim. as new and desire to secure by Letters Patent of the United States is:

1. A switch operating mechanism comprising a shaft, a disc-shaped cam means, eccentric means on said shaft for imparting an eccentric movement to said cam means, means cooperating with said cam means to effect a lesser angular displacement of said earn means in response to angular displacement of said shaft, hub means on said shaft, extensible handles pivoted in said hub means, notches in said cam means, and projections on said handles adapted to engage said notches to lock said shaft when said handles are pivoted to positions parallel to said shaft.

2. A switch operating mechanism comprising an operating shaft, disc-shaped cam means, means on said sh'aft imparting an eccentric movement to said cam means upon rotation of said shaft, pin means on said cam means, fixed annular plate means having internal crenelations cooperating with said pin means to effect angular displacement of said cam means upon angular displacement of said shaft, hub means on said shaft, handle means pivotally mounted in said hub means, and projections on said handle means arranged to engage notches in said cam means to inhibit rotation of said shaft when said handles are pivoted to positions parallel to said shaft.

3. A switch operating mechanism comprising an operating shaft, disc-shaped cam means, means on said shaft impart-ing an eccentric movement to said cam means upon rotation of said shaft, pin means on said cam means, fixed annular plate means having internal crenelations cooperating with said pin means to effect lesser angular displacement of said cam means upon angular displacement of said shaft, hub means on said shaft, a pair of linearly extensible handles pivoted to said hub means, a pair of notches in said cam means, and projections on said handle means arranged to engage said notches to inhibit rotation of said shaft when said handles are pivoted to positions parallel to said shaft.

4. A switch operating mechanism comprising an operating shaft, eccentric means on said shaft, disc cam means freely rotatable on said eccentric means, a pair of pins on said disc cam means, fixed annular plate means having internal crenelations, said pins being positioned to engage said crenelations such that angular displacement of said eccentric means eflfects a predetermined lesser angular displacement of said cam means, hub means on saidshaft, a pair of extensible handles pivoted to said hub, and means for locking said shaft comprising a pair of notches in said cam, and a projection on each of said handles, said projections being positioned to engage said notches when said handles are pivoted to positions substantially parallel to said shaft.

5. A switch operating mechanism comprising an operating shaft, disc-shaped cam means, means on said shaft imparting an eccentric movement to said cam means upon rotation of said shaft, pin means on said cam means, fixed annular plate means having internal crenelations cooperating With said pin means to effect lesser angular displacement of said cam means upon angular displacement of said shaft, hub means on said shaft having a pair of oppositely disposed bifurcations, a pair of linearly extensible handles pivoted in said bifurcations, a pair of notches in said cam means, and projections on said handles arranged to engage said notches to inhibit rotation of said shaft when said handles are pivoted to positions parallel to said shaft.

6. A switch operating mechanism comprising an operating shaft, an eccentric portion on said shaft, a hub on said portion having an eccentric complementing said eccentric portion, disc cam means freely rotatable on said eccentric and having a pair of pins extending therefrom, fixed annular plate means having internal crenelations cooperating with said pins to efiect a lesser angular displacement of said cam means upon angular displacement of said shaft, a pair of oppositely disposed bifurcations in said hub, 21 pair of linearly extensible handles pivoted in said bifurcations, one of said handles being pivoted for movement in a first plane passing through the axis of said eccentric and the other handle being pivoted for movement in a second plane parallel to said first plane, and a pair of notches in said disc cam means, the ends of said handles engaging said notches to lock said shaft when said handles are pivoted to positions parallel to said shaft.

References Cited in the file of this patent UNITED STATES PATENTS 290,029 Furney Dec. 11, 1883 541,840 Diehl July 2, 1895 2,356,914 Blancha d. Aug. 29, 1944 FOREIGN PATENTS 715,435 France Dec. 3, 1931

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