US2571960A - Grounding switch operating mechanism - Google Patents

Description

C. W. SMITH GROUNDING SWITCH OPERATING MECHANISM Oct. 16, 1951 2 SHEETS-SHEET 1 Filed Oct. 20, 1949 INVENTOR Charles W. Smith.

WITNESSES:

Oct. 16, 1951 c. w. SMITH 2,571,960

GROUNDING SWITCH OPERATING MECHANISM Filed OG'b. 20, 1949 2 SHEETSSHEET 2 WITNESSES: INVENTOR 1 Charles W.Smi1h I BY Patented Oct. 16, 1951 STATES A'iENT orrics GROUNDENG SWi'liflfi'. OPERATING MECHANISM- in iaims. 1.

This invention relates to transformer grounding switches and particularly to the operating mechanism for actuating grounding switches.

In the operation of electrical apparatus such as transformers, it is desirable to disconnect the transformer from the power circuit and to ground the high voltage feeder when repairs or changes are to be made in order to protect the workman from injury in case someone should accidentally close. the line breaker and again connect the transformer to the circuit. It is also desirable to provide for preventing the improper operation of the grounding switch such, for example, as moving it from the open position to the ground position when the transformer or feeder is energized, which operation might cause serious damage to the apparatus or persons.

' Transformer grounding switches have been developed heretofore for accomplishing such operations, but such switches utilize operating mechani'sms which consist of many complex mechanical parts which are subject to frequent replacement due to wear and breakage, a factor resulting in the loss of much time and money to the industry. I

An object of the invention is to provide an operating mechanism for effecting a positive movement. of a transformer grounding switch from an open position through a transformer position to: the ground position.

Another object of the invention is to provide an operating mechanism for effecting a positive stop of a transformer grounding switch at the transformer position during movement of the switch from an open position to the ground position andto provide means associated with the operating mechanism to effect a positive lock of the transformer grounding switch when the switch is in any one of the open, transformer and ground positions.

A further object of the invention is to provide an operating mechanism for a transformer grounding switch which is of a very simple mechanical structure, permitting operation of the switch. by an inexperienced operator and reducing the time and expense involved in repairing and replacing faulty parts.

Other objects of the invention will become apparent from the following description of an operative embodiment of the invention when taken in. conjunction with the accompanying drawings, in which:

Figure 1 is a view in side elevation of the operating mechanism;

Fig. 2 is a view in front elevation of the op- 2 crating mechanism for the grounding switch ill'u'strated' as positioned in the open position;

Fig. 3 is a view similar to Fig. 2' illustrating the operating mechanism for the grounding switch at a position between the open and transformer positions of the switch during movement of the switch from the open position towards the ground position;

Fig; is a view similar to Fig. 2' illustrating the operating mechanism for the grounding switch positioned at the transformer position;

Fig. 5 is a view similar to Fig. 2 illustrating the operating mechanism for the grounding switch at a position between the transformer and ground positions of the switch during movement of the switch from the open position towards the ground position;

Fig. 6 is a view similar to Fig. 2 illustrating the operating mechanisms for the grounding switch positioned at the ground position; and

Fig. 7 is an enlarged front view of a part of the operating mechanism of Figs. 1 through 6 illustrating the three relative positions assumed by a positive. stop member during movement of the switch from the open position through the transformer position to the ground position.

Referring to the drawings and in particular to Figs. 1 and 2. there is illustrated a grounding switch operating mechanism 10 embodying the teachings of this invention. In this embodiment' the mechanism It] is provided with a chan nel support member 2 for mounting the mechanism on a suitable panelboard or the like (not shown), the channel member t2 having a shaft 54 extending outwardly therefrom at one end thereof disposed to be rotated relative thereto. In order to operate the grounding switch (not shown) through a number of switching positions such as open, transformer and ground positions, a lever i6 is disposed with one end thereof secured to the shaft M, the other end being adapted to be secured to the grounding switch (not shown). The lever I6 is thus rotatable with the shaft It to progressively actuate the grounding switch (not shown) through predetermined positions as the shaft M is rotated.

In. order to effect the rotation of the shaft [4' and consequently actuate the lever it, an arm member 13 is provided having one of its ends secured to the shaft I4. The arm member 'l'8' can therefore be rotated relative to the channel support member I2. As illustrated, the arm member it is provided with a shaft 20 adjacent the free end thereof and disposed for rotation therein. An operating handle 22 is provided. on the shaft 28 to effect the rotation thereof and to move the arm member is to effect thereby a corresponding rotation of the shaft hi to move the lever it through the various switch positions.

Mounted on the base of the support member I2 is an arcuate member 24 having disposed therein a pair of offset recesses or slots 25 and 28 having sides 38-32 and .3436 respectively. The offset recesses or slots 26 and 23 are disposed longitudinally of the arcuate member 24 to cooperate With recess engaging means (referred to hereinafter) affixed to the end of the shaft 20 for effecting a control of movement upon the shaft 28 and consequently for effecting a. corresponding control of movement upon the grounding switch (not shown) during movement of the grounding switch (not shown) from the open position through the transformer position to the ground position. The recess engaging means comprises a segmentally shaped element 38 having a fiat side 45 and a curved side 42, the element 38 being disposed for predetermined movement along the slots 28 and 28 and to engage restraining means disposed in spaced relation along the recesses or slots 26 and 28 in predetermined positions to effect a positive stop of the element 38 in such positions. In this instance the restraining means along the offset slots 28 and 28 comprise a number of substantially circular enlargements 44, 46 and 48 of the recesses or slots 26 and 28, the enlargements being disposed in positions corresponding respectively to the ground, transformer and open positions of the grounding switch (not shown).

In order to prevent movement of the grounding switch (not shown) from the open position to the ground position directly, the enlargement 45 is disposed between the enlargements 44 and 48 for interconnecting the adjacent ends of the offset recesses or slots 26 and 28 to provide a tortuous path for movement of the element 38 between the open and ground positions. The enlargement 46 comprises an arcuate extension 58 of one terminal of the recess side 30 and an arcuate extension 52 of one terminal of the recess side 36. As viewed in Figs. 2 through '7 the extensions 50 and 52 are disposed in diametrically opposite relation and have the configurations of minor arcs of a circle (not shown), the extensions 58 and 52 being disposed for joining together the recess sides 30, 34 and 32, 36 respectively, to provide the tortuous path for movement of the element 38 between the open and ground positions.

The enlargement 44 is disposed for receiving the element 38 therein for effecting a corresponding positioning of the grounding switch (not shown) in the ground position, and comprises an arcuate extension 54 of the other terminal of the recess side 38. The extension 54 is disposed for joining together the recess sides 30 and 32 of the recess 26 and has the configuration of a major arc of a circle (not shown), the center of the circle (not shown) being offset in a direction toward the recess side 32 in relation to an arc line (not shown) disposed midway between the recess sides 30 and 32 and having a curvature identical to the curvature of the recess sides 30 and 32.

The enlargement 48 is disposed for receiving the element 38 therein for effecting a corresponding positioning of the grounding switch (not shown) in the open position, and comprises an arcuate extension 56 of the other terminal of the recess. side 38. The extension 56 is disposed for joining together the sides 34 and 36 of the recess 28 and has the configuration of a major arc of a circle (not shown), the center of the circle (not shown) being offset in a direction toward the recess side 34 in relation to an arc line (not shown) disposed midway between the recess sides 34 and 36 and having a curvature identical to the curvature of the recess sides 34 and 35.

Referring to Fig. l, a locking mechanism 58 is illustrated as disposed for operation to effect a positive lock of the operating mechanism for the grounding switch (not shown) in any one of the open, transformer and ground positions. The mechanism 58 comprises a circular locking plate 60 carried by the shaft 20 adjacent the arm member l3 and disposed for rotation with the shaft 26 relative to the arm member I8. The locking plate 68 is secured to the shaft 29 as by a friction fit or may be keyed thereto, the shaft 20 extending through an aperture 62 therein which is disposed in offset relation to the center of the locking plate 86. In order to provide a positive lock for the operating mechanism when the mechanism is in any one of the open, transformer or ground positions, a spring-biased detent 64 is carried by the locking plate 60 adjacent the outer edge thereof at a point diametrically opposite the aperture 62 in the locking plate 68 for cooperating with an aperture 68 adjacent the end of the arm 18 as described hereinafter.

The detent 64 comprises a shaft 68 extending through an aperture 18 in the locking plate 68, the shaft 68 having affixed to one end thereof a knob i2 disposed to be manually actuated to move a ball-like protuberance or end 14 of the shaft 68 at the other end thereof, out of engagement with the aperture 66 in the arm member l8 when the operating mechanism is to be actuated from any one of the open, transformer and ground positions. In order to bias the end 14 into engagement with the aperture 66, a compression spring 16 is disposed about the shaft 68 between the end 74 thereof and the plate 60. Thus, when the operating mechanism is in any one of the open, transformer or ground positions, it may be locked by rotating the handle 22 to rotate the plate 68 to a position where the end 74 of the detent 84 is biased into engagement with the aperture 66. On the other hand, the operating mechanism may be unlocked by a simple lifting of the knob 72 to compress the spring 16 and move the end 14 out of engagement with the aperture 66.

The following description of operation of the grounding switch operating mechanism l8 when taken in conjunction with Figs. 2 through 7 and especially Fig. 7 will serve to illustrate how the desired positive stop of the grounding switch (not shown) is effected at the transformer position during movement of the grounding switch (not shown) from the open position to the ground position.

As shown in Fig. 2, the element 38 is positioned within the enlargement 48 for effecting the positioning and a positive stop of the grounding switch (not shown) in the open position. In order to initiate the movement of the grounding switch (not shown) toward the transformer position, it is necessary to release the locking mechanism 58 which operates to lock the operating mechanism in the open position. This is accomplished by moving the knob 12 outwardly from the plate 60 to compress the spring 16 and disengage the end 14 from the aperture 65 as described hereinbefore... Upon. the:- release. of the locking mechanism 58, theshaft28 is thenactuated in. a direction; for eifecting: a 9.0" rotation of the element 38 in a counterclockwise:direction to swing the: fiat side. 40. of. the element. 38 into alignment with the recess side 34'. thereby per:- mittingmovement of. the element 38 along the recess or slot; 28 away from the: enlargement 48 asthe: arm I8- is: moved for effecting a corre-' sponding movement of the: lever 16 and. the grounding switch (not-shown) toward the trans-'- former'position. Itlis' apparentthat an. actuation of theshaft 28 in a. direction to effect a 90rotation" of theelement 38 in a clockwise direction would: fail to permit movement of the element 38 along therecess or s1ot28 since, upon effecting such. clockwise rotation, the. curved side 42 of the element 38 is positioned inthe recessed region- 18 of the recess side 34 formedby the extension 56 of therecess side 36- to: thereby prevent movementof the element 38 away fromthe enlargement-48. Thiseifectivel'y prevents move ment of the arm l8 and consequently prevents a corresponding movement of the grounding switch (notshown) toward the transformer position.

It can'be'seen that movement of the grounding switch (not shown) isthus prevented while the element 38- isso disposed for if a force is applied tothe shaft 20- to tend to actuate the element longitudinally of the recess or slot 28 to effect a corresponding movement of the grounding switch (not shown) toward the transformer position, a portion of the curved side 42- of the element 38 is in engagement with a part of the recessedregion 18 thereby preventing movement of the element 38- away from the enlargement 48 to prevent a corresponding movement of the grounding switch (not shown) toward the transformer position;

Withthe element 38- rotated toa position where the flat side 40 thereof is in alignmentwith. the side 34 of the recess 28 asdescribed hereinbefore, a force isapplied to the operating handle 22 to move the element- 38- and consequently the arm 18- towards the transformer position as shown in- Figs. 3 andie. As illustrated, a positive stop is provided: in the transformer positionby reason of the enlargement 46 con.-

necting the oifset slots 25 and 2 8. As the element 38 is movedinto engagement with the enlargement-46, the curved side 42 engages the extension 52 to prevent further continuous movement of; the operating: mechanismtowards the grounding position. When the element 38 is moved into position in the enlargement 46 as describedfor effectinga corresponding movement of: the grounding switch (not shown) into the transformer. position, the. element. 38. is disposed as is illustrated in Figs. 4 and 7..

Further movement of the grounding switch not shown) away from the transformer position adirection toward the ground position may beeffected only upon the performance of a predetermined operation by the switch operator, which operation is time consuming, thereby efiecting'the desired positive stop of the grounding' switch (not shown) at the transformer position. The effect of. the positive stop is to give the switch operator the opportunity of deter"- mining' whether or not the transformer is energized, the grounding. switch (not shown) being in the transformer position during: the delay or positive stop. Such. a positive stop also. provides sufficient. time delay to permitrthe. operation of electrical interlocks; (not shown) which are usually associated with the grounding switclr..- If the operator discovers that the transformer is energized, he may have the breakers again thrown open, whereupon he may perform the predetermined operation for permitting movement of the grounding switch (not shown) into the ground position without fear of causin damage to the transformer or the switch.

In order to effect the further movement of the operating mechanism". towards the ground position from the transformer position illustrated in Fig. 4,11; is necessary to actuate the. shaft 28 in a direction for eifecting a 180 rotation of the element 38 in the clockwise direction for moving the curved side 42 of the. element 38 out of engagement with the extension 52, thereby swinging, the fiat side 48 of the element 38 around intoalignment with the recess side 32 A subsequent actuation ofthe shaft 20, while the element 38 is so disposed, in a direction for actuating the element longitudinally of the-recess or slot 25 as shown in Fig. 5, effects a. movement of the operating mechanism and consecLuent-ly a corresponding movement of the grounding switch (not shown) toward the ground'posi tion illustrated in Fig. 6; H

The performance of the predetermined operation and the subsequent actuation of the shaft 28 having been completed, free, movement of the grounding switch (not shown) is permitted toward the ground position. After the element 38 is moved into the enlargement 44 for efiecting a corresponding movement of the grounding switch (not shown) into the groundposition, the switch operator must then actuate the shaft 20 by means of the operating handle 22 in a direction to effect a rotation of the element 38 in a counter-clockwise direction for operating. the locking mechanism 58 to lock the operatingmeche anism' and the grounding switch (not shown) in the ground position, thereby preventing accidental or unauthorized movement of the grounding switch (not shown) from. the ground position.

The invention .as described possesses several features of advantage over the grounding switches utilized in the industry today. The operating mechanism comprising the invention has relatively few mechanical parts and is, therefore, capable of prolonged service uninterrupted by breakdowns and failures. of the operating parts, thereby resulting. in a more efficient operation and. less. expenditure of time andmoney.

Improper operation of the operating mechanism is made impossible by the inclusion of the positive stop means-for providing a positive stop of the grounding switch at the transformer position during movement of the switch from the open to the ground position. Movement of the switch directly from the open to the ground position is thereby prevented. The inclusion. of the positive stop means thus prevents-the:- switch operator from connecting. the power circuit; con ductors' to ground while. energized, an operation which would result in the. presence of a heavy grounding current and possible destruction of the switch. During the positive stop of the switch at the transformer position, the operator may determine whether or not. the transformer is energized and throw open the circuit breakers if the transformer is. found tobe energized and the electrical. interlock (not. shown) is. operated;

The switch may then bemoved. into the ground position without fear of injury to the apparatus 'or the workmen. f A further feature of the invention which practically assures a safeguard against injury to the apparatus or the workmen is the locking mechanism associated with the operating mechanism of the'grounding switch. The operation of the locking mechanism in any one of the various switch -positions prevents the accidental or unauthorized movement of the switch operating mechanism from any one of the switch positions. It will be understood that a padlock or other suitable locking device may be utilized in lieu of the detent 64.' Many modifications of the structure illustrated and described may be made within the spirit of the invention.

I claim as my invention:

1. In an operating mechanism for effecting the movement of a transformer grounding switch between an open position, a transformer position, and a ground position, in combination, a support member for the operating mechanism, a member having a longitudinal recess therein affixed to the support member, an arm member pivotally mounted on the support member, a shaft rotatably carried by the arm member, recess engaging means carried by the shaft disposed for movement longitudinally of the recess, a plurality of restraining means disposed in spaced relation along the recess to correspond to the open, transformer and ground positions of the switch, one of the restraining means cooperating with the recess engaging means for effecting a positive stop of the switch at the transformer position during a movement of the switch from the open position to the ground position, and means carried by the shaft disposed to cooperate with the arm member when the recess engaging means is in any one of the open, transformer and ground positions for locking the recess engaging means in such position.

2. In an operating mechanism for effecting the movement of a transformer grounding switch between an open position, a transformer position, and a ground position, in combination, a support member for the operating mechanism, a member having an arcuate longitudinal recess therein afiixed to the support member, an arm member pivotally mounted on the support member, a shaft rotatably carried by the arm member, recess engaging means carried by the shaft disposed for movement longitudinally of the recess, and a plurality of restraining means disposed in spaced relation along the recess to correspond to the open, transformer and ground positions of the switch, one of the restraining means cooperating with the recess engaging means for effecting a positive stop of the switch at the transformer position during a movement of the switch from the open position to the ground position.

3. In an operating mechanism for effecting the movement of a transformer grounding switch between an open position, a transformer position and a ground position, in combination, a support member for the operating mechanism, a member having a plurality of arcuate longitudinal recesses therein affixed to the suport member, an arm member pivotally mounted on the support member, a shaft rotatably carried by the arm member, recess engaging means carried by the shaft disposed for movement longitudinally of the recesses, and a plurality of restraining means disposed in spaced relation along the recesses to correspond to the open, transformer and ground positions of the switch, each of the restraining means comprising a substantially circular enlargement of the longitudinal recesses, the en largement corresponding to the transformer position being disposed to interconnect the adjacent ends of the plurality of recesses to provide a tortuous path for movement of the recess engaging means along the recesses from the open position, through the transformer position, to the ground position, one of the restraining means cooperating with the recess engaging means to effect a positive stop of the switch at the transformer position during a movement of the switch from the open position to the ground position.

4. In an operating mechanism for effecting the movement of a transformer grounding switch between an open position, a transformer position and a ground position, in combination, a support member for the operating mechanism, a member having an arcuate longitudinal recess therein carried by the support member, an arm member pivotally mounted on the suport member, a shaft rotatably carried by the arm member, recess engaging means comprising a segmentally shaped element having a flat lateral surface carried by the shaft disposed for movement longitudinally of the recess, restraining means disposed in spaced relation along the recess corresponding to the open, transformer and ground positions of the switch, and means carried by the shaft disposed for operation to rotate the recess engaging means when the engaging means is in the transformer position whereby the flat surface of the engaging means cooperates with one side of the recess between the open and transformer positions and with the other side of the recess between the transformer and ground positions to control movement of the switch and effect, a positive stop thereof in the transformer position during such rotation.

5. In an operating mechanism for effecting the movement of a transformer grounding switch between an open position, a transformer position and a ground position, in combination, a support member for the operating mechanism, an arcuate member having a plurality of arcuate longitudinal recesses therein carried by the support member, an arm member pivotally mounted on the support member, a shaft rotatably carried by the arm member, and recess engaging means carried by the shaft disposed for movement longitudinally of the recesses, the recess engaging means coinprising a segmentally shaped element disposed for cooperation with restraining means disposed in spaced relation along the recesses to effect a positive stop of the switch at the transformer position during movement of the switch from the open position to the ground position.

6. In an operating mechanism for effecting the movement of a transformer grounding switch between an open position, a transformer position, and a ground position, in combination, a support member for the operating mechanism, a member having an arcuate longitudinal recess therein carried by the support member, an arm member pivotally mounted on the support member, a shaft rotatably carried by the arm member, recess engaging means comprising a segmentally shaped element having a flat lateral surface carried by the shaft and disposed for movement longitudinally of the decess, restraining means disposed in spaced relation along the recess corresponding to the open, transformer and ground positions of the switch, means carried by the shaft disposed for operation to rotate the recess engaging means 180 when the engaging means is in the transformer position whereby the fiat surface of the engaging means cooperates with one side of the recess between the open and transformer positions and with the other side of the recess between the transformer and ground positions to control movement of the switch and effect a positive stop thereof in the transformer position during such rotation, and means carried by the shaft disposed to cooperate with the arm member when the recess engaging means is in any one of the open, transformer and ground positions for locking the recess engaging means in such position.

7. In an operating mechanism for effecting the movement of a transformer grounding switch between an open position, a transformer position, and a ground position, in combination, a support member for the operating mechanism, a member having an arcuate longitudinal recess therein afiixed to the support member, an arm member pivotally mounted on the support member, a shaft rotatably carried by the arm member, recess engaging means carried by the shaft disposed for movement longitudinally of the recess, a plurality of restraining means disposed in spaced relation along the recess to correspond to the open, transformer and ground positions of the switch, one of the restraining means cooperating with the recess engaging means for effecting a positive stop of the switch at the transformer position during a movement of the switch from the open position to the ground position, and means carried by the shaft disposed for imparting a predetermined rotating movement to the engaging means in each of the open, transformer and ground positions.

8. In an operating mechanism for efiecting the movement of a transformer grounding switch between an open position, a transformer position and a ground position, in combination, a support member for the operating mechanism, a member having a plurality of arcuate longitudinal recesses therein affixed by the support member, an arm member pivotally mounted on the support member, a shaft rotatably carried by the arm member, recess engaging means carried by the shaft disposed for movement longitudinally of the recesses, a plurality of restraining means disposed in spaced relation along the recesses to correspond to the open, transformer and ground positions of the switch, each of the restraining means comprising a substantially circular enlargement of the longitudinal recesses, the enlargement corresponding to the transformer position being disposed to interconnect the adjacent ends of the plurality of recesses to provide a tortuous path for movement of the recess engaging means along the recesses from the open position, through the transformer position, to the ground position, one of the restraining means cooperating with the recess engaging means to effect a positive stop of the switch at the transformer position during a movement of the switch from the open position to the ground position, and means carried by the shaft disposed to cooperate with the arm member when the recess engaging means is in any one of the open, transformer and ground positions for locking the recess engaging means in such position.

9. In an operating mechanism for effecting the movement of a transformer grounding switch between an open position, a transformer position, and a ground position, in combination, a support member for the operating mechanism, a member having an arcuate longitudinal recess therein afiixed to the support member, an arm member pivotally mounted on the support member, a shaft rotatably carried by the arm member, recess engaging means carried by the shaft disposed for movement longitudinally of the recess, a plurality of restraining means disposed in spaced relation along the recess to correspond to the open, transformer and ground positions of the switch, each of the restraining means comprising a substantially circular enlargement of the longitudinal recess, one of the restraining means being disposed to cooperate with the recess engaging means to effect a positive stop of the switch at the transformer position during movement of the switch from the open position to the ground position, and means carried by the shaft disposed to cooperate with the arm member when the recess engaging means is in any one of the open, transformer and ground positions for locking the recess engaging means in such position.

10. In an operating mechanism for effecting the movement of a transformer grounding switch between an open position, a transformer position and a ground position, in combination, a support member for the operating mechanism, a member having an arcuate longitudinal recess therein carried by the support member, an arm member pivotally mounted on the support member, a shaft rotatably carried by the arm member, recess engaging means disposed for movement longitudinally of the recess, the recess engaging means comprising a segmentally shaped element disposed for movement simultaneously with movement of the shaft, a plurality of restraining means disposed in spaced relation along the recess to correspond to the open, transformer and ground positions, one of the restraining means cooperating with the segmentally shaped element for effecting a positive stop of the switch at the transformer position during a movement thereof from the open to the ground position, a plate member carried by the shaft, and locking means disposed to prevent relative movement of the plate member to the arm member when the segmentally shaped element is in any one of the open, transformer and ground positions for locking the segmentally shaped element in such position.

CHARLES W. SMITH.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,577,757 Re Qua Mar. 23, 1926 1,791,469 Maranda Feb. 3, 1931 2,369,690 Roth Feb. 20, 1945 FOREIGN PATENTS Number Country Date 10,600 Great Britain May 2, 1911

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