US1836838A - Control of electric switches - Google Patents

Description

Dec. 15, 1931- F. T. COLDWELL CONTROL OF ELECTRIC SWITCHES Original Filed April 27, 192'? 2 Sheets-Sheet N M s 4 w ML P w c c. .1

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b4 8 a. v3? e f 3 L 30 I 000 lllll Inventor Frank T. ColdweH, 193 M I A His Attorngy.

Patented Dec. 15, 1931 2 UNITED STATES PATENT OFFICE FRANK '1. COLDWELL, OI ALPLAUS, NEW YORK, ASSIGNOR '10 GEN ERAL ELECTRIC COM-' PANY, A. CORPORATION OF NEW YORK CONTROL OF ELECTRIC SWITCHES Application filed April 27, 1927, Serial My invention relates to improvements in the control of electric switches and particularly circuit breakers. An object of my invention is to provide improved control apparatus such that there is always available until the next operation a definite indication of the last operation whether performed autbmatically or manually. Another object of my invention is to provide improved control apparatus such that a circuit breaker cannot be maintained closed under the conditions for which it is intended to be open.

My invention will be better understood from the following description when considered in connection with the accompanying drawings and its scope will be pointed out in the appended claims.

In the accompanying drawings, Fig. 1 illustrates in perspective a control switch embodying my invention, Fig. 2 illustrates diagrammatically an embodiment of my invention in a circuit breaker control compris- .ing the switch shown in Fig. 1, Figs. 3 a to f inclusive illustrate diagrammatically the different contact controlling positions of the switch shown in Fig. 1 as applied to the circuit breaker control shown in Fig. 2, Fig. 4 illustrates diagrammatically another embodiment of my invention in a circuit breaker control comprising the switch shown in Fig. 1, and Figs. 5 a to f inclusive illustrate diagrammatically the different contact controlling positions of the switch shown in Fig. 1 as applied to the circuit breaker control shown 1n Fig. 4.

The control switch shown in Fig. 1 comprises an operating member, such as a shaft 10, arranged for both rotary and translatory movements, a rotatable member or contact controlling element which may be a sleeve 11 concentric with and rotatable on the shaft 10 and means mechanically interconnecting them so that the sleeve can be rotated only on the translation of the shaft after a predetermined angular movement thereof.

The shaft 10 is mounted for both the rotary and lengthwise movements in bearing plates 12, 13 which may be suitably secured to a base late 14 so as to form a part of'the switch rame. A tie plate 15 which may also No. 187,080. Renewed July 24, 1931.

serve as a terminal and contact supporting member and is then preferably of insulating material, is secured to the bearing plates 12 and 13. For securing the switch to a panel, suitable fastening means such as screws 16 may be passed through an escutcheon plate 17 on one side of the panel, not shown, and through the panel into the bearing plate 13 on the other side of the panel. The shaft 10, which is also arranged to project through the panel, is biased for lengthwise movement in a mounted on the plate 15 and while the arms 20,

21 are shown as a single member they may be separate. Also secured to the shaft 10 is an operating handle or knob 26 on which, in order to accentuate the angular position of the shaft, I prefer-to mount a strip of material 27 so contrasting with the color of the handle as to be easily distinguishable at a distance. With the handle oval shaped as shown, this gives not only a shape but also a color distinction as to the position of the handle.

The sleeve 11 by its rotation is arranged to control a plurality of contacts 28 to inclusive which are mounted on the plate 15. For this purpose and in order to secure a predetermined sequence in the operation, the sleeve may comprise one or more cams 36 Whose contour as shown' is that of a circle minus a segment thereof. These cams 36 are arranged to actuate contact supporting members 37 which carry bridging contacts and which as shown are guided by the contacts and by central stems 38 which project through holes in the plate 15 and a bearing strip 39.

The supporting members 37 are biased towards their respective cams by suitable means such as springs 40 and by reason of the holes for the stems 38 being somewhat larger than the stems a tilting action occurs on contact opening so that a wiping action is obtained. Inthe switch illustrated the cams 36 are so arranged that the pairs of contacts including 28 to 33 are open when the contacts 34, .35 are closed and vice-versa, an angular movement of 90 in the direction indicated by the arrow 25 or the reverse rotation serving to shift from either to the other. The interconnecting means for effecting rotation of the sleeve 11 on rotation of the shaft 10 followed by lengthwise movement thereof in a direction opposite that indicated by the arrow 18 comprises as shown a crank 41 secured to the shaft 10 and carryin a crank pin 42, a crank 43 rotatably mounte on the shaft 10 but reciprocable therewith and v carrying a crank pin 44, a resilient connection such as a tension spring 45 between the cranks 41 and 43,-a crank 46 secured to the sleeve 11 and arranged to be engaged by the crank pin 44 and an interlock plate 47 mounted on the plate 15 and provided with holes in the path of movement of the crank pin 44.

The crank 41 as shown is arranged to permit a substantially 90 movement of the shaft 10 in the direction indicated by the arrow 25 and reverse. For this purpose and so that the shaft 10 cannot be rotated after it has been moved lengthwise a predetermined amount in a direction opposite that indicated by the arrow 18, the crank 41 is provided with slots 48, 49 the extreme sides of which are long enough to engage the lower portion of a stop 50 mounted on the base plate 14. These slots are arranged to receive the higher portion of the stop 50 when the shaft 10 is retracted a predetermined amount. Thus in the switch position shown in Fig. 1, the shaft 10 can be rotated substantially 90 in the direction indicated by the arrow 25 until the longer side of the slot 49 enga es the lower portion of the stop 50 if the sha t is not retracted far enough to have both sides of the slot 49 engage the higher portion of the stop 50. This latter interlock occurs before the shaft 10 can be retracted sufliciently to close contacts 22, 23 or 23, 24. The torsion spring 45 is supported on the hub of the crank 43 and is ar ranged so to bias the cranks 41 and 43 and,

therefore, the crank 46 that they tend to assume the same angular osition. For this purpose the free ends of the spring 45 are arranged on opposite sides of the crank pins 42 and 44 with enough initial bias to hold the crank 41 with the longer side of one of the slots 48, 49 against the lower portion of the stop 50. The crank pin 44 although rlgidly secured to the crank 43 is movable lengthwise in its opening in the crank 46 and the holes in the plate 47. In order to reduce the friction between the cranks 43 and 46, they may be spaced by washers on the shaft 10 and a separator plate 51 secured to the base plate 14. The washer 52 between the plates 51 and the crank 43 is suitably secured to the shaft 10 so that on retraction thereof the crank moves with the shaft. Also in order to prevent overtravel of the sleeve 11 stops 53 arranged in the path of movement of the sleeve crank 46 may be provided.

With the switch parts positioned as shown ,in Fig. 1 only the contacts 34 and 35 are bridged or closed. If the shaft 10 is retracted by pulling outwardly on the handle 26 against the bias of the spring 19, the shaft cannot be turned since the slot 48 in the crank 41 will engage the higher portion of the stop 50. If the shaft 10 is retracted sufficiently the contacts 22, 23 may be bridged by the arm 20, but no change will occur in the contacts controlled by the rotation of the sleeve 11. If, however, the shaft 10 instead of being retracted is rotated by turning the handle in the direction indicated by the arrow 25, energy will be stored in the spring 45 and the rotation will cease when the long side of the slot 49 engages the lower portion of the stop 50. The shaft 10 and, therefore, the crank 43 may now be retracted sufficiently to draw the crank pin 44 out of the hole in one side of the plate 47. In this retractive movement of the shaft 10, the contacts 23, 24 are bridged by the arm 21 prior to the release of the crank pin 44, the contacts 22, 23 and 24 being so mounted as to allow further retractive movement of the shaft after they are engaged by their respective circuit controlling arms. On the release of the crank pin 44 from the plate 47', the cranks 43 and 46 and, therefore, the sleeve 11 will under the bias of the spring 45 be quickly rotated in the direction indicat'ed by the arrow 25 until the crank pin 44 registers with the hole in the other side of the plate 47 Now when the handle 26 is released, the shaft 10 and therefore the crank pin 44 will under the bias of the spring 19 be counter-actuated or moved in the direction indicated by the arrow 18 and consequently the crank pin 44 will pass through the registering hole in the plate 47, thus locking the sleeve 11 against rotation. The rotation of the sleeve 11 effected by the energy stored in the spring 45 causes the opening of the contacts 34, 35 and the closing of the contact pairs comprising contacts 28 to 33 inclusive. The handle 26 and the strip 27 are now vertical and will so remain until the handle is turned in a direction opposite that indicated by the arrow 25 and then retracted sufficiently to release the crank pin 44 from its hole in the plate 47. In this reversed rotation and subsequent retraction, the contacts 22 and 23 are bridged by the circuit controlling arm 20 and the contacts 28 to 35 inclusive restored to the condition shown in Fig. 1 with the handle 26 and strip 27 horizontal- This operation will be obviousfrom the preceding.

In Figs. 2 and 4, I have illustrated embodiments of my invention as applied to a latched closed type of circuit breaker 54 which is arranged to control a circuit 55 and which is provided with suitable opening and closing means. These are s own as comprising trip and closing coils 56 and 57 respectively. The circuit of the trip coil 56 may be controlled by means responsive to a condition of the circuit 55 such as an over-current relay 58 which is arranged to be energized in accordance with the current in a conductor of the circuit in any suitable manner as by a current transformer 59 in the case of an alternating current circuit. The circuit breaker is also provided with auxiliary switches comprising contacts. 60 and 61 which are arranged to be closed when the circuit breaker is open and vice-versa and contacts 62 which are arranged to be closed when the circuit breaker is closed and open when it is open. Since the closing coil 57 may require a relatively large current, it is frequently preferable to control its circuit through a control relay 63 which is provided with contacts suitable for the purpose and which is of the instantaneous closing time delay opening type so as to allow time for the latching of the circuit breaker.

In order to have a visual indication of the closing of the circuit breaker 54, there is provided a red lamp 64 whose circuit is controlled by the auxiliary switch contacts 62 and which may be in series with the trip coil 56 to indicate a failure of the tripping circuit while the circuit breaker is closed. In order to have a visual indication of the opening of the circuit breaker, there is provided a white lamp 65 which is in series with the auxiliary switch contacts and may also be in series with the winding of the control relay 63 so as to indicate a failure of the control relay circuit while the circuit breaker is open. For an audible indication of the automatic opening of the circuit breaker 54, that is by the operation of the relay 58 for example,

there may be provided a suitable device such as a horn-66 which may serve for one or more circuit breakers.

For controlling the opening and closing means and the indicating means, I employ in accordance with my invention a control switch such as illustrated in Fig. 1 so ar-' ranged as to provide independently of the operator an absolute indication of the last operation performed. In Figs. 2 to 5 the control switch is illustrated schematically for simplicity as a rectangle embracing merely the contacts 22, 23, 24 and 28 to 35 inclusive together with the contact bridgin members and connection arrangements 0 the contacts. Thus, for example, in Figs. 2, 3a, 4, and 5a, the control switch is illustrated with the contacts and bridging member in the condition shown in Fig. 1.

Referring now in particular to Figs. 2 and 3 a to f inclusive, the contacts 22 and 35 are connected by a lead 67, the contacts 23 and thereby leaving the 30 by a lead 68 and the contacts 24 and 32 by a lead 69. The circuit breaker 54 is open and the circuit of the white lamp 65 is completedas follows: the auxiliary switch contacts 61, the control relay 63, the conductor 70, the lamp 65, and the resistor 71. The resistor 71 is so chosen that the white lamp 65 is dimly lighted when all of the resistor is in series with the lamp. The control switch handle 26 is horizontal, the circuit of the horn 66 is open at contacts 28, 29, the

v circuit of the control relay 63 is open at the control switch contacts 23, 24 and also at the contacts 32 and 33, and the circuit of the trip coil 56 is open at the auxiliary switch contacts 62 and also at the control switch contacts 22, 23.

To close the circuit breaker 54, the handle 26 is turned in the direction of the arrow 25, Fig. 1, and pulled. The initial pull closes the contacts 23 and 24 through the arm 21 as shown in Fig. 3b and the final pull effects the rotation of the sleeve 11 thereby open= ing the contacts 34, 35 and closing the contact pairs comprising the contacts 28 to 33 inclusive as shown in Fig. 30. The circuit of the control relay 63 is thereby completed through the contacts 32, 33 and 23, 24. Through this relay and the closing coil 57 the closing of the circuit breaker is efiected. The circuit of the horn 66 is momentarily completed. This gives a test of the horn.

The circuit of the white lamp 65 is momentarily completed through only a portion of the resistor 71 sufiicient to permit "a more intense illumination of the lamp. .This ives a test of the lamp. The operatlng han le 26 is now vertical and the red lamp 64 is lighted. When the handle is released, the arm 21 opens the contacts 23, 24 as shown in Fig. 3d, circuit of the control relay 63 open in case the circuit breaker should open.

If the circuit breaker is tripped automatically, that is by the relay 58, the circuit of the red lamp 64 is broken at the auxiliary switch contacts 62 and the circuit of the white lamp 65 is completed through the auxiliary switch contacts 61, the conductor 70, the lamp 65, the upper portion of the resistor 71, and the contacts 30, 31. In this case the lamp 65 gives a more intense indication than when the circuit breaker is tripped manually so that where several circuit breakers are controlled from one switchboard,i-;a mere glance at the switchboard will enablethe operator to tell which of the circuit breakers has opened. This eliminates any necessity for distinguishable audible signals for the different circuit breakers. Consequently one audible indicator such as the horn 66 may be used for all the circuit breakers. The'circuit of the horn 66 is completed through the auxiliary switch contacts 60 and the control switch contacts 28, 29. To stop the born 66 and reduce the intensity of theflanup 65, if the circuit breaker is to reniain open, the operating handle 26 is turned oppositely to the direction indicated by the arrow 25 in 5 Fig. 1 and pulled. The initial pull closes the contacts 22 and 23 by the arm as shown in Fig. 3e and the final pull effects the reverse rotation of the sleeve 11 thereby closing contacts 34 and 35 and opening the contact pairs comprising the contacts 28 to 33 inclusive as shown in Fig. 3f. This opens the circuit of the horn 66 at the contacts 28, 29 and the circuit of the control relay 63 at the contacts 32, 33 and by opening the contacts 30, 31 cuts in all of the reslstance 71 in the circuit of the white lamp 65 which therefore produces a less intense indication, that is like the white lamps of other circuit breakers which may be open. The control switch handle 26 is go now horizontal and when released returns to the position shown in Fig. 1. When the circuit breaker 54 is tripped by the operation of the control switch, the circuit of the trip coil 56 is closed at the contacts 34, 35 and 22.

23 by operating the control switch as described above in connection with Figs. 36 and f. In this case the horn 66 is not sounded and thewhite lamp 65 instead of showing bright and dim shows dim only.

36 In the modification of my invention shown in Fig. 4, the control is such that the operator cannot maintain the circuit breaker 54 closed under the conditions for which it is intended to be open. For this purpose the connections difier from those in Fig. 3 and an auxiliary relay 72 is so arranged that the'operator cannot hold the circuit breaker closed or reclose the circuit breaker without first going through the tripping operation.

In this case, the contacts 23 and 35 are connected by. a lead 73, the contacts 23 and 30 by a lead 74, and the contacts 32 and 34 by a lead 75. The circuit of the control relay 63 is now arranged so that it can be completed only when the auxiliary relay 72 is energized and its contacts 76 closed. When the control switch'parts are positioned as shown in Fig. 1 and as indicated schematicallyin Figs-4 and 5a, the circuit of the auxiliary'relay 72 is completed when the circuit breaker 54 is open as follows: auxiliary switch contacts 61,

conductor 77, resistor 78, relay 72, control switch contacts 34, 35 and leads 73 and 74. If the control switch has not been operated to the tripping position as indicated in Figs. 4 and 5a, it will of course be impossible for the relay 72 to close its contacts -7 6, since the control switch contacts 34, 35 will be open. If.

now the operating handle 26 is turned in the direction indicated by the arrow 25 in Fig. 1 and retracted, the control switch contacts 23 and 24 will be closed by the arm 21, thus clos-' ing the circuit of the relay 2 through its contacts 23 and 24 before the control switch contacts34 and 35 are opened on the final pull of the operating handle which efiects the rotation of the sleeve 11. The control switch contacts are now in the condition shown in Fig. 50 and the handle 26 is vertical. The circuit of the control relay 63 is completed as follows: auxiliary switch contacts 61, control relay 63, control switch contacts 33, 32, lead 75, auxiliary relay contacts 76, control switch contacts 24, 23 and lead 74. When the control switch handle is released, the contacts 23 and 24 are opened as shown in Fig. 5d thereby opening the circuits of both the control relay 63 and the auxiliar relay 72. Since the latter can be energize only when the control switch contacts 34, 35 and the auxiliary switch contacts 61 are closed, the operating handle 26 must be turned oppositely to the direction indicated by the arrows 25 in Fig. 1 and retracted to cause the rotation of the sleeve 11. During this operation as shown in Figs. 5 e and f, the circuit of the trip coil 56 is completed as follows: the auxiliary switch contacts 62, thetrip coil 56, the conductor 7 9, the control switch contacts 22, 23 and the lead 74. The control switch handle 26 when released is horizontal and the control switch contacts as indicated in Figs. 4 and 5a. The circuits of the lamps 64 and 65 and the horn 66 will be obvious by analogy with those traced in connection with the description of Fig. 2.

While I have shown and described my invention in considerable detail, I do not desire to be limited to the exact arrangements shown, but seek to cover in the appended claims all those modifications that fall within the true spirit and scope of my invention.

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

1. A switch comprising an o erating mem- 10 ber adapted to be rotated an to be moved engthwise, a rotatable contact controlling element, means for rotating said element arranged to have energy stored therein on rotation ofsaid member and means for pre- 11 venting rotation of the element until the member has been rotated a predetermined amount arranged to be released on a predetermined lengthwise movement of the member in one direction. 11

2. A control switch comprising an operating shaft adapted to be rotated'and to be moved lengthwise, a contact controlling sleeve concentric with the shaft and rotatable relatively thereto, means for rotating the sleeve 11 arranged to have energy stored therein on rotation of the shaft and means for preventing the energy storing means from rotating the sleeve until the shaft has been rotated a predetermined amount arranged to be re- 11 leased on a predetermined lengthwise movement of the shaft in one direction. I

3. A switch comprising an operating member arranged for rotary and translatory movements, an element arranged for rotary 1 movement and means mechanically inter-- connecting the member and the element for efi'ecting rotation of the element only aiter the member is rotated a predetermined amount and then translated a predetermined amount in one direction,

4. A switch comprising two rotatable concentric members one of which is arranged for translatory movement and means mechanically interconnecting the members for eilectmg rotation of the other member only after the one member is rotated predetermined amount and then translated a predetermined amount in one direction.

5. A control switch comprising a rotatable contact controlling element and actuating means therefor comprising a rotatable and lengthwise movable operating member, means for biasing said operating member for lengthwise movement in one direction and means operative on a predetermined lengthwise movement of said operating member in the opposite direction after a predetermined angular movement thereof for effecting the rotation of said element from one contact controlling position to another.

6. A control switch comprising a rotatable contact controlling element and actuating means therefor comprising a rotatable and lengthwise movable opera-ting member, means for biasing said operatin member for lengthwise movement in one irection, means operative on a predetermined lengthwise movement of said operating member in the "oppo site direction after a, predetermined angular movement thereof for effecting the rotation of said element from one contact controlling position to another, and contacts arranged to be controlled by said operating member on the lengthwise movements thereof.

7. A control switch comprising a rotatable contact controlling element and actuating means therefor comprising a rotatable and lengthwise movable operating member, means for blasmg said operating member for length ,wise movement in one direction, means operative on a predetermined lengthwise movement of said operating member in the oppo:

site direction after a predetermined angular movement thereof for effecting the rotation of said element from one contact controlling position toanother, and contacts arranged to be controlled by said operating member on the lengthwise movements thereof and to cooperate with the contacts controlled by said element,

8. A switch comprising a rotatable and translatable operating member, a rotatable element, and means for effecting rotation of said element only after said member is rotated a predetermined amount and then translated. a predetermined amount in a given direction,

9 A switch comprising two rotatable members, one of which is arranged for translatory movement and means for effecting rotation of the other member only after the one memher is rotated at predetermined amount and then translated a predetermined amount in a given direction.

10. A switch comprising a plurality of movable contacts, a movable member for actuating said movable contacts to one contact controlling position, means "for producing a connter-actuation of said member to move one of said contacts to another trolling position and means for anoth r contact of said conta s file contact controlling position to which it was moved until a further actuation of said movable member,

11. A switch comprising plurality oi" fixed contacts, a plurality cooperating movable contacts, a movable member for actuating said movable contacts to engage their respective fixed contacts, means for producing a countenactuation of said member to disengage one of said movable contacts, and means for maintaining another movable contact in the engaged position until a further actuation of said movable member,

In witness whereof, E have hereunto set my hand this 26th day oi April, 1927,

FRANK T, COLDWELL.

contact con-

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