US2868921A - Switch actuator - Google Patents

Description

Jan. 13, 1959 M. RIGERT 2,86

SWITCH ACTUATOR Filed Sept. 29, 1955 3 Sheets-Sheet l L INVE NTOR. Max 94397?! BY %W M M. RIGERT SWITCH ACTUATOR Jan. 13, 1959 5 Sheets-Sheet 3 Filed Sept. 29, 1955 INVENTOR. Max Bayer: BY

Httorngr United States Patent SWITCH ACTUATOR Max Rigert, West Allis, Wis., assignor t0 McGraw-Edison Company, a corporation of Delaware Application September 29, 1955, Serial No. 537,359

8 Claims. (Cl. 200-87) This invention pertains to an improved electromechanical actuator and more particularly, but not exclusively, to a device for opening and closing a circuit interrupter from a remote station.

It has been conventional practice to accomplish electromechanical operation of circuit interrupters by resorting to one of the following alternatives;

First, by employing a pair of solenoids which may be selectively energized for individually driving the interrupter into opened and closed positions, respectively; or, secondly, by employing a single solenoid, which during one of its strokes, drives the interrupter and simultaneously stores energy in a spring which provides energy for a return stroke.

Where the first above mentioned practice is followed, it is immediately apparent that there would be advantage in eliminating one of the solenoids, because considerable cost reduction would be effected. This results not only from reduction in the number of solenoids but also from eliminating mechanical and electrical interlocks and other accessories frequently used with such arrangements. in the second example, Where a single soleniod is employed, it must obviously be inordinately large in order to deliver energy for opening and closing operations while executing a single power stroke. Moreover, additional relays or mechanical trips are often required for releasing the g energy stored in the spring.

This invention avoids the above complications and disadvantages and has as one of its principal objects the provision of an actuator embodying but a single solenoid assembly capable of performing both switch opening and switch' closing operations.

Another object of the invention is to provide mechanism which automatically conditions suitable auxiliary controls'witches for enabling the solenoid to execute alternate opening and closing strokes in response to intermittently applied electric signals.

Yet another object is provision of an actuator which is mutually noninterfering; that is, the device to which the actuator is attached may be operated without interference from the actuator and the actuator may perform normally without impairing manual operation. 7 A still further object is the provision of an inexpensive, simplified and improved actuator. Achievement of the foregoing and other more specific objects will be evident throughout the specification which follows.

An example of a circuit interrupter to which the novel actuator may be applied, is illustrated in U. S. Patent No. 2,560,831, issued July 17, 1951, to A. Van Ryan et al. and assigned to the assignee of this invention.

In general terms, the novel actuator is characterized as a unitary structure which includes as its prime mover a solenoid and plunger assembly. Through suitable linkage, alternate reciprocations of the plunger are converted to alternate oscillations of an oscillator cam segment from which the power output of the actuator is directly derived. Actuated by the oscillator segment is another system of linkage constituting an over-center arrangement which transfers its position on either side of its rotational center in response to oscillations of the segment. In this illustrative embodiment, the over-center linkage is arranged to alternately actuate a pair of normally closed auxiliary selector switches which, in conjunction with a control station, prepare the solenoid for its next operation immediately following its last one. Incorporated in the overcenter linkage is a tension coil spring which performs the dual function of causing the over-center linkage to act with a quick motion and in addition, restores the plunger to its uppermost or inactive position in preparation for its next power stroke.

A more detailed description of the invention will now be given with reference to the drawings in which:

Fig. 1 represents in elevation acircuit recloser provided with the novel actuator enclosed in its housing;

Fig. 2 is a front elevation view of the actuator, with parts in section and parts broken away, the components thereof being in a first inactive or de-energized position;

Fig. 3 is a section view taken on a line corresponding with 3-3 of Fig. 2, certain components being represented fragmentarily;

Fig. 4 is a back elevation view taken with reference to the structure represented in Fig. 2;

Fig. 5 shows in elevation the disposition of the actuator components during one active or energized step of its operational sequence;

Fig. 6 shows in elevation the disposition of the actuator components when in a second inactive or tie-energized position; and

Fig. 7 illustrates one form of circuit diagram for use in conjunction with the novel actuator.

In Fig. 1 the novel actuator, designated generally by the reference numeral 1 is shown mounted on a sleet hood 2 forming part of a cover 3 of an oil circuit recloser such as that illustrated in detail in the above cited Van Ryan et a1. patent.

The reclosing type circuit interrupter of Fig. 1 is provided with an eyeleted operating handle 4 which may be engaged by a hook stick, not shown, for manually opening or closing its main electrical load contacts, not shown. Shaft 7, upon which handle 4 is keyed, is part of the recloser mechanism as will be evident from inspection of the cited patent. As illustrated, recloser handle 4 is in its uppermost position corresponding with closed circuit position of the recloser main contacts. It is well known in the art, that after the recloser executes a number of rapid, closely successive operations it will lock out its main contacts, due to inherent structure illustrated in the cited patent, thereby causing handle 4 to rotate counterclockwise with shaft 7 through an angle of less than degrees, thus visually indicating that the recloser is in open circuit condition. It will appear more fully hereinafter that the structure of the actuator is such that it does not interfere with the free automatic operaion of recloser handle 4 and that manual operation of the closer handle 4 will not interfere with the normal electromechanical operation of actuator 1.

Fig. 2 is a section View taken through the housing 6 of the actuator and shows its interior mechanism in considerably greater detail. Note that operating handle 4 is provided with a second arm 9 which is connected to an oscillator 10 in the form of an oscillating cam segment through the agency of a power output link 5 which passes through an aperture 11 in the bottom of housing 6. It is evident that by this arrangement, operating handle 4 will be raised and lowered in accordance with oscillations of cam segment 1%.

Power for oscillating segment 10 is derived from a solenoid assembly including a magnetic coil 13 and a plunger 14 adapted to reciprocate in the magnet coil in response to alternate energization and de-energization thereof. A

walking-beam type power input lever 15, driven by plunger 14, is mounted on a fixed or stationary pivot 16 and is connected at one end to a cross pin 17 in the free end of plunger 14 by means of an elongated hole 18. Hole 18 is elongated to compensate for binding which may result from connection of the linearly moving plunger to the swinging power input lever 15.

Pivotally connected at 19 to power input lever is an intermediate link 22 connected through a pin 23 to a crank arm 24. Crank arm 24 is fixedly pinned on a shaft 25 which is journalled in suitable bearings 26 provided in a pair of spaced supporting plate members 27 and 23, respectively. Support plates 27 and 28 support other bearing members to be described hereinafter, as well as fixed pivot pin 16 of the power input lever 15, referred to above. Near the end of shaft 25 remote from crank 24, a cam actuating lever 30 is fixedly pinned to shaft 25. In the illustrative embodiment, the angular position of actuating lever 30 is practically coincident with that of crank 24 and since crank 24 and actuating lever 30 are each permanently pinned to shaft 25 they maintain their angular coincidence, one concealing the other in the elevation views.

Oscillator segment 10 is journalled for free rotation on a reduced portion 31 of shaft 25 substantially midway between upstanding support plates 27 and 28. Angular positioning of segment 10 is controlled by its interengagement with actuating lever 30. In the preferred form of the invention here illustrated, this is accomplished by providing the actuator lever 30 with a drive pin 32 (see Fig. 3) which extends laterally into a sectorial notch 33 in oscillator segment 10. Notch 33 is defined by angularly spaced radially extending edges 34 and 35 against which pin 32 of the actuator lever may selectively strike in order to oscillate segment 10.

Although segment 10 has a substantially circular configuration in the preferred embodiment, other configurations for it may be elected. For example, it may be formed as a three armed bell crank journalled on shaft 25 and having arms extending therefrom to define the equivalent1 20f notch 33 and another arm for supporting transfer PlIl From the structure thus far described, with attention directed mainly toward Figs. 2, 3 and 4, it will be evident that energization of solenoid coil 13 will cause plunger 14 to execute a rapid downward motion which will in turn rotate power input lever 15 in a counterclockwise direction, as viewed in Fig. 2. Through intermediate link 22, this will cause angular rotation of crank 24 and accordingly, actuator lever 30. After the small free play between actuator drive pin 32 and radial edge 34 of the segment is taken up, pin 32 will cause edge 34 and segment 10 to be driven through a limited counterclockwise angle, thereby causing power output link 5, which is pivotally pinned at 36 to segment 10, to move downwardly. It may be remarked that whether segment 10 is in a first angular position such as in Fig. 2 or a second angular position such as in Fig. 6, some clearance or free play is maintained between actuator pin 32 and radial edges 34 and 35, respectively, for the purpose of permitting the actuator pin to gain some momentum before commencing to drive the segment ltl. This tends to overcome the inherent initial weakness in the magnetic pull of solenoid 13 on plunger 14 when a considerable portion of the plunger is extending from the solenoid, as in Figs. 2 and 6.

In proceeding with the detailed description of the actuator it will be appreciated that means must be provided for restoring plunger 14 to its uppermost position, as in Fig. 2, after it has executed a working stroke and solenoid coil 13 has been de-energized. According to the invention this is accomplished by use of a transfer lever 40 which is pivoted intermediate its ends on a fixed pin 41 supported on one of the vertical support plates 28. In the preferred form of the invention a transfer pin 42 is fixed in oscillator segment 10 and extends laterally thereof into the Cir 4 slotted end 43 of the transfer lever 40. Of course, the converse arrangement is also possible, that is, pin 42 may be carried by transfer lever 41) and a slot may be provided in segment 10 to obtain the same cooperation between those elements. Thus, in Fig. 2 it is evident that a counterclockwise rotation of transfer pin 42 along with segment 11) will cause transfer lever 40 to rotate in a clockwise direction and the slotted end 43 thereof to assume a new position on the left side of a line drawn through transfer lever pivot 41 and the center of shaft 25 supporting the segment. This latter result is observable in Figs. 5 and 6.

A coil spring 46 interconnects the free end of transfer lever 40 through the agency of a grooved cross pin 47 further supported on a pivotal arm 48. The other end of spring 46 attaches to an end of actuator lever 30 through the medium of a slot 49 and a cooperating pin 50 arranged in an obvious manner. It will be seen in the ensuing paragraphs how transfer lever 40 and actuator lever 30 interact upon each other during an operational sequence of the actuator so that restoration of the plunger to its uppermost position, after de-energization, will be achieved.

Although electrical control of solenoid coil 13 will be completely explained hereinafter, in conjunction with Fig. 7, it may here be commented that a pair of two pole, short stroke normally closed switches 52 and 53 are provided for that purpose. An appropriate form of switch is that designated Microswitch. These auxiliary selector switches 52 and 53 are supported on vertical support plate 27 in the swinging path of cross pin 47 being driven by actuator lever 40. Thus, in Figs. 2 and 4, it is evident that for a first position of operating handle 4, switch 52 is depressed to open circuit condition by cross pin 47, whereas, in Figs. 5 and 6, corresponding with a second position of operating handle 4, switch 53 is depressed open. in place of individual selector switches 52 and 53 may be substituted a unitary single pole double throw switch such as suggested by 57 in Fig. 7.

Automatic preparation of the single solenoid plunger 14 for executing its next operational stroke is accomplished by an electric circuit illustrated schematically in Fig. 7 and corresponding with conditions of Fig. 2. Here two broken line enclosures are shown, the first being designated by numeral 55 encloses the electrical components to be found in the actuator proper. The second broken line enclosure 56, embodies a single pole double throw switch 57 which would most likely be located at a station quite remote from the circuit interrupter to be controlled by the actuator 1. Switch 57 is shown in neutral position and is merely illustrative, it being understood that a push button station, the contacts of an induction relay, or any other control means may be substituted for it. A pair of power lines 58 and 59 at a nominal voltage such as volts are provided, one of which 59 runs directly to one side of solenoid coil 13. One terminal 60 and 61 of each auxiliary switch 52 and 53, respectively, is connected to the other by means of a jumper 62 which is in turn joined to another terminal of solenoid coil 13.

For a position corresponding with that of the actuator .in Fig. 2, it will be noted that switch 52 is in open position and that 53 is in normally closed position. Thus, if control switch 57 is swung clockwise so as to contact terminal 65, a circuit will be completed through control switch 57, auxiliary switch 53 and solenoid 13. Upon this event, segment 10 will execute its counterclockwise angular swing as viewed in Fig. 2 and transfer bar 40 will swing to the opposite sides of its center as depicted in that figure so that auxiliary switch 52 will close and 53 will open (see Fig. 6). Thus the actuator is placed in a condition of readiness for another operation in response to closing of control switch 57 against terminal 64.

Having described the various components of the actuator in detail, its mode of operation will now be outlined. Refer to Figs. 2, 3 and 4 where the actuator 1 is in inactive position, that is, de-energized electrically, and

either of two directions.

eyeleted operating handle 4 as in its uppermost position corresponding with closed circuit position of the circuit interrupter. Now if the solenoid coil 13 is energized by closing remote control switch 57 against its terminal 65, coil 13 will first slowly and then rapidly attract plunger 14 downwardly to its active position in Fig. 5. This will cause actuator lever 30 to rotate counterclockwise and pin 32 carried thereby to react against radial edge 34 of sectorial notch 33, thereby rotating segment to the position shown in Fig. 5. At the same time, transfer pin 42 rocks counterclockwise to the position illustrated in Fig. 5 and return spring 46 is fully extended between cross pin 47 and actuator lever 30. Now recloser operating handle 4 is driven to its lowermost counterclockwise position as in Fig. 5 and the power stroke is completed. Note that, in Fig. 5, cross pin 47 is now depressing auxiliary selector switch 53 thus opening it.

After completion of the power stroke, it is necessary to withdraw the plunger 14 from solenoid 13. Since energization of the solenoid plunger has been terminated by automatic opening of auxiliary selector switch 53 the mechanism is in condition for coil spring 46 to take over from its extended position in Fig. 5 so that following in rapid sequence to de-energizati'on of coil 13, the spring will flip actuator lever 30 in a quick clockwise direction until its pin 32 comes to rest near radial edge 35 of the segment as illustrated in Fig. 6. This action causes a corresponding clockwise rotation of shaft and crank arm 24 so that' plunger 14 is elevated by the action of intermediate link 22 cooperating with power input lever 15. in Fig. 6 it will be observed that return spring 46 is now on the right hand side of a line of action extending from shaft 25 through the axis of fixed transfer bar pin 41 as compared with Fig. 2 where it rests on the left hand side of the sarn'e'line. Consequently, the actuator 1, resting in a second inactive position, is now in readiness for a converse operation.

Assuming that it is desired to manually swing eyeleted operating handle 4 from its position in Fig. 2 to that of Fig. 6, this may be done without interference or the necessity of re-cycling the actuator. Hence, the actuator has the attribute of being trip-free. In other words, merely pulling downwardly on the handle from its Fig. 2 position, will cause a force to be exerted on oscillator cam segment 10 so that transfer lever 40 will rock to the same final position in Fig. 6 thus allowing auxiliary selector switch 52 to close as if the actuator had been elec tromechanically operated. Of course, pulling on eyeleted handle 4 will exert a corresponding torque on recloser shaft 7 thus actuating the recloser to open circuit position. By reason of spring 46 being provided, actuator lever and actuator pin 32 will be urged into its lost motion relation adjacent radial edge as described above in connection with electrical operation.

In summarizing, the aforego-ing specification has described an actuator for a switch or any other mechanical device, which embodies but a single solenoid although it performs equal quantities of work when operating in The actuator is further seen to include a compact assembly of easily formed components. Moreover, the actuator may be used to operate a switch from a remote station, or in the alternative, the switch may be operated manually without interference or impairment of the proper operational sequence of the actuator by itself.

It is claimed:

1. A switch actuator comprising, a solenoid coil having a reciprocable plunger therein, a shaft, linkage means interconnecting said plunger and said shaft for converting alternate reciprocations of said plunger into alternate oscillations of said shaft between predetermined angular limits, an oscillator rotatable about the axis of said shaft, actuating lever means fixed on said shaft and in engagement with said linkage means and said oscillator for oscillating the latter about said shaft axis in response to intermittent energizations and de-energizations of said solenoid coil, spring means interposed between said transfer means and said actuating lever means for storing energy while said oscillator moves from one position and for releasing that energy when said oscillator substantially reaches its other position, selector switch means adapted to close and open the circuit to said solenoid coil in accordance with the change of oscillator angular positions, transfer means actuable by said oscillator for operating said selector switch means and for positioning said plunger, and power output means interconnected with said oscillator.

2. A switch actuator comprising, a solenoid coil having a reciprocable plunger therein, a shaft, linkage means interconnecting said plunger and shaft for converting alternate reciprocations of said plunger into alternate oscillations of said shaft between predetermined angular limits, an oscillator journalled for rotation on said shaft, actuating lever means rigid with said shaft and in engagement with said oscillator for actuating the latter from one to another angular position in response to intermittent energizations and de-en'ergizations respectively of said coil, transfer means movable from one to another posi tion in synchronism with corresponding positions of said oscillator, spring means interposed between said actuating lever means and said transfer means for storing energy while said oscillator is in movement to another position during energization of said coil and for releasing that energy to said actuating lever means when said coil is de-energized, whereby said plunger is forced to its initial position, selector switch means adapted to close and open the circuit to said solenoid coil in accordance with the change in oscillator angular positions, means for operating said selector switches, and power output means interconnected with said oscillator.

3. A switch actuator comprising, a solenoid coil having a reciprocable plunger therein, linkage means interconnecting said plunger and shaft for converting alternate reciprocations of said plunger into alternate oscillations of said shaft between predetermined angular limits, an oscillator journalled for rotation on said shaft, actuating lever means rigid with said shaft and in engagement with said oscillator for driving the latter from one to another angular position in response to intermittent energizatio-ns and deenergizations respectively of said coil, transfer means movable from one to another posi tion in synchronism with corresponding positions of said oscillator, said transfer means including a fixedly pivoted lever engaged at one end with said oscillator and having spring attaching means at the other end, said oscillator being adapted to drive said pivoted lever to opposite sides of a line extending from the shaft axis through the pivoted lever axis, over-center spring means interposed between said lever and actuating lever means for storing energy while said oscillator is in movement to another position during energization of said coil and for releasing that energy to said actuating lever means when the coil is deenergized, whereby said plunger is forced to its initial position, selector switch means adapted to close and open the circuit to said solenoid coil in accordance with the change of oscillator angular positions, said selector switch means being operated by said transfer means, and power output means interconnected with said oscillator.

4. The invention according to claim 3 wherein said oscillator comprises, a disc having a sectorial notch therein and said actuating lever means including means freely engaging said actuator between radial limits of said notch.

5. In a circuit interrupter including an actuator therefor, the combination of an operating handle manually placeable in a first position and automatically and manually swingable to a second position, a solenoid having a reciprocable plunger therein, a shaft, linkage means in terconnecting said plunger and shaft for converting al ternate reciprocations of said plunger into alternate oscillations of said shaft between pre-determined angular limits, an oscillator rotatable in either angular direction about the axis of said shaft, means connecting said oscillator in power exchange relationship with the operating handle, actuating lever means carried rigidly by said shaft and including means in lost motion engagement with said oscillator for oscillating the latter about said shaft axis in response to intermittent energizations and de-energizations of said solenoid coil, said lost motion engagement permitting said operating handle to swing to either of its two positions substantially unimpeded by said actuator, means responsive to changes in angular positions of the oscillator for controlling the solenoid circuit, and spring means interposed between said last named means and said actuating lever means for storing energy while said oscillator moves under the influence of said plunger during energization of said solenoid coil and for releasing that energy to said actuating lever when said solenoid coil is deenergized.

6. In a circuit interrupter including an actuator therefor, the combination of an operating handle manually placeable in a first position and automatically and manually swingable to a second position, a solenoid having a reciprocable plunger therein, a shaft, linkage means interconnecting said plunger and shaft for converting alternate reciprocations of said plunger to alternate oscillations of said shaft between predetermined angular limits, an oscillator rotatable in either angular direction about the axis of said shaft, means connecting said oscillator in power exchange relationship with said operatmeans and said actuating lever means for storing energy while said oscillator moves from one position and for releasing that energy to said actuating lever when said oscillator substantially reaches its other position, and means operable by said transfer means in response to changing angular positions of said oscillator for controlling the solenoid circuits.

7. The invention according to claim 6 wherein said oscillator comprises, a disc having a sectorial notch therein and said actuating lever means including means freely engaging said oscillator between radial limits of said notch.

8. A switch actuator comprising a solenoid having a reciprocable plunger therein, a shaft, actuating lever means affixed on said shaft, link means connecting said actuating lever means and said plunger for converting reciprocation of the plunger into oscillations of the shaft, oscillator means journalled for rotation on said shaft, said actuating lever means normally being in one position of separable engagement with said oscillator means, transfer lever means operatively connected with said oscillator for changing angular positions therewith, overcenter spring means connected between said actuating lever means and said transfer lever means, said spring means being placed in stored energy condition by manual rotation of said oscillator and by said plunger rotating said oscillator, when said oscillator moves through a predetermined angle said spring means being adapted to yield its stored energy for shifting said actuating and transfer levers to different positions and for positioning said plunger through the agency of said link means.

References Cited in the file of this patent UNITED STATES PATENTS 1,007,886 Miller Nov. 7, 1911 1,916,360 Crane July 4, 1933 1,956,847 Ainsworth May 1, 1934 2,497,466 Olson Feb. 14, 1950

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