US1588893A - Electric switch - Google Patents

Description

, l1922 4 sheets-sheet` 1 June 15 1926.

H. K. KRANTZ ELECTRIC SWITCH Filed August 8 Fig, 1.

June 15 ,1926. 4 1,588393 H. K. KRANTZ ELECTRIC SWITCH Filed Aug-ust a, 1922 AL(Sheets-Sheet 2 Fig,

'WITNESSES: INVENTOR Hdber'f K. Kran-fz.

Q JWM ATTORNEY Jim; ,15 ,1926. 1,588,893

' H. K. KRANTZ ELECTRIC SWITCH Filed August 8, 1922 Sheets-Sheet 5 Fig. 15 H314.

WITNESSES: I A INVENTOR Huber+ K. Krarvz.

ATTORNEY June 15 1926.

. H. K. KRANTZ ELECTRIC swITcH Filed August 8. 1922 4'slwets-Shee't. 4

WITNESSES:

A INVENTOR K. .M 81 82 'r9 5e Huberlh'mnfz.

ATTORNEY Patented June 15, 192.6.

i UNITED STATES PATENT oFFicE.

HUBERT x. KRANTZ, or WILKINSBURG,

PENNSYLVANIA, ASSIGNOB T0 WESTING- HOUSE ELECTRIC & MANUFACTURINGCOMPAINY, ACORPOBATION OF PENNSYL- VAN IA.

ELECTRIC SWITCH.

vApplication led August 8, 1922. Serial No. 580,409.

My invention relates to electric switches and particularly to those of the type wherein more than one switching operation is cm3 ployed for starting motors. V

My invention is particularly applicable for use in connection with small motors, such as are employed for driving household appliances and it has for one of its objects the provision of a compact structure embodying switches for controlling the circuits through the starting and running windings of a motor, together with means for automatically interrupting the circuit through the motor in case a short circuit or an overload occurseither during the starting of the motor or when such motor is operating under running conditions.

Another object of my invention is the provision of means whereby the switch that controls the circuit through ,the starting winding will be automatically moved to open position after suiiicient time has elapsed to enable the motor to attain its normal running speed. i

Another object of my invention is the provision of a simplified form of operating mechanism whereby but a single handle is necessary in order to manual}y e'ect the operation of both switches.

A further object of my invention is the provision of means whereby the position of the operating handle when at rest indicates the position occupied by the running switch.

Another object of my invention is the provision of an improved form of trip-freeI mechanism whereby the switch may be automatically disengaged from the closing mechanism, when the switch reaches its closed position in order to insure that the switch will not be held closed against an overload on the circuit.

Still another object of my invention is to' simplify and improve generally the construction and operation of circuit controlling devices of the character above ,referred to.

As shown in the accompanying drawings, A 4Figure 1 is a plan view of a switch embodymg my invention7 the cover and the handle being removed,

Fig. 2 is a view, partially in side elevation and partially in section, of the switch,

Fig. 3 is a detailview of the stationary contact members,

. Fig. 4 is a plan view of the cover plate,

Figs. 5 and 6 are side elevational and plan views, respectively, of the handle bracket,

Figs. 7 and 8 are plan and side elevational views, respectively, o the bracket which carries the movable contact members of the `running switch,

Figs. 9 and 1.0 are plan and side elevational views, respectively, of the bracket which carries the movablecontact members of the starting switch,

Figs. 11 and 12 are plan and side elevational views, respectively, of thev lever for locking the. running switch, v

Figs. 13 and 1.4 are detail views of the upper and lower bearings respectively for the movable contact bracket members,

Fig. 15 is a detail view of one of the pins employed for effecting a connection between thehandle bracket and the moving parts of' the switch,

Fig. 16 is a plan view showing the positions occupied by certain of the moving parts at one stage of their operation,

Fig. 17 is a diagrammatic view showing the relation of the switches with respect to the circuits that are controlled thereby, and

Fig. 18 is a detail view, in perspective, 4of certain of the tripping mechanism which I employ.

The switch is provided with a cover 18 Aand a base 19. A frame 20 is secured to the base 19 by bolts 21. A bearing 23 is secured to the front of the :trame 20 and is perforated to permit the passage therethrough of a handle shaft 24 that carries a handle 25 which may be osoillated between stop members 26 and 27, the stop members consisting of bent-up portions of the frame 20. A rear bearing 28 is secured to the base 19 by upsetting the lower end at 29 (Fig. 2). The lower end of the shaft 24 is flattened slightly so that the handle bracket 31 may be non-rotatably engaged thereby, by reason of the contour of a hole 32 in the bracket. (See Fig. 6.) The bracket 31 is of U-shape and is provided with a slot 33 at its middle portion within which a pin 34 may slide horizontally.

yThe pin 34 is provided with" grooves 36 (Fig. 15) that are engaged by the ends of a pair of tension springs 37. T'he other ends of the springs .37 are Supported-.by a pin 38, the upperxpand lower ends of which lie in the cut-out portions 39 (Fig. 9) of a carrier 41 for movable contact members V42 (only one of which is shown in Fig. 1) that co-operate with stationary contact members 43 to close the circuit through a starting winding of a motor connected in the circuit.

When the handle 25 is turned in a counter-clockwise direction, the pin 34, by reason .of its locationin the slot 33 of the handle of its ends by the pin 38, Ain a groove similar to the grooves 36 of the pin 34, and at its other end is supported by a pin 51 whose ends lie in recesses 52 of another movable contact bracket 53 (Fi s. 1, 7 and 8) that serves Cas a support or movable contact members 54 that aremoved into and out of engagement with stationary contact members 56 to etl'ect a closure of what is herein designated as the running switch.

When the startinglswitch bracket 41 and the pin 38 that is supported thereby are turned in a counter clockwise direction, the spring 49, which is under tension, is carried across'the axis of the rotatable members, thereby changing the direction of tension exerted by such spring 49 upon the bracket, 53 and causing such bracket to be moved to the osition shown in Fig. 16. At this stage of t e operation, the running and starting switches are both closed. v

As the contact car-rying brackets 53 and f 41 move in clockwise and counter-clockwise directions, respectively, shouldered portions 57 of the bracket 53 engage the front and rear ends, respectively, of the pin 34, moving it radially out of engagement with the shouldered portion 44 of the bracket 41, thus ldisengaging such bracket and permitting lswitch, the movementof the bracket 41 increases the tension of the spring 58. Upon -the pin 34 being tripped free of the shoulder v 44 of the bracket 41, as above described,lthe

tension of the spring 58 is sufficient to return the bracket 41 to the position shown switches are in t in Fig. 1, against the tension of the springs 37 and 49. This movement also returns that lportion of the spring 49 which is supported By tlile pin 38 to 'the position illustrated in A locking lever 62 is pivotally supported in the. frame 20, by a pin 60, and is normally biased in a clockwise direction by the spring 63 (Figs. 1 and 2). A pin 64 extends through openings 65 in the lever 62 and carries rollers 66 at its front and rear ends. When the bracket 53 has been moved to the position shown in Fig. 16, the rollers 66, by reason of the clockwise tension cxerted upon the lever 62 will engage a pair of shoulders 67 on the bracket 53 to hold the bracket 53 in closed position (as shown in Fig. 16) against the tension of the spring 49, when the end of that spring 4which is supported by the pin 38 has been returned to the position shown in Fig. 1, as above explained.

The return movement of the bracket 41, under the-tension of the spring 58, places the handle bracket 31 under tension, by`

reason of the elongation of the springs 37,A

but the bracket 31 is prevented from moving to .o position so long aspthe pin 34 remains in en a ement with the shouldered portion 57 o t e bracket 53. The position` occupied bythe handle 25, with respect to the stop lugs 26 and 27, thus indi the running switch is closed;

An electromagnet 68 for controlling the starting switch comprises two coils, 69 and 70, that may contain unequal ampere turns, and which are connected in the circuit, as shown in Fig. 17, to co-operate with an armature 71 which is carried upon a tail piece 72 of the starting switch bracket 41. The differential in the magnetic forces of the coils excited on the armature 71 is sufficient to hold the startin switch closed when the e position occupied in 16.

The effective holding force of themagnet 68 varies, as will be hereinafter ex lained, but normally holds the starting switc closed against the tension of the spring 58 for a short period. When the magnetism has been sufficiently reduced, as will be hereinafter explained, the tension of the spring 58 will impart an opening \movement to 'the starting switch, as described above.

With the starting switch in the position illustrated in Fig. 1, and the running switch as illustrated in Fig. 16, the motor will operate under normal running conditions and may be stopped either by manually effecting an opening movement of the running switch or by automatically effecting such movement.

rI he running switch may be opened manually by turning thehandle 25 in a clockwise direction, thus bringing the` beveled portions 73 (Figs. 5 and 6) of the handle brackcates that Y los et 31 into engagement with the rollers 66 to cam them out of engagement with the shouldered portions 67 of the bracket 53. The handle is then held in its off position against the stop 26, by the tension of the springs 37, and the running switch bracket 53 is snapped to its open position by the tension of the spring 49.

The running switch may be opened automatically upon the occurrence of an overload by the coil 70 that actuates an armature 74 which is pivotally supported upon the pin and is biased outwardly by a spring 63a. An abnormal energization of the coil 70 will attract the armature 74 against the tension of the spring 63a, and move it into engagement with lugs 62a of the lever 62 and causes a'counter clockwise movement by the lever 62, thus moving the rollers 66 out of engagement with the shoulders 67 of the running switch bracket and permitting the spring 49 to return the running switch bracket 53 to open position. The opening movement ofthe bracket 53 causes the release of the pin 34 from its engagement with the shoulders 57 and allows the handle 25 to be returned to its of position, as in the case of the manual operation above described.

As shown more clearly in Fig. 4, the frame 2O is provided with stop portions 76 for engaging the front ends of the pins 38 and 51 to lnnit. their movements, the rear ends of` the pins engaging the end walls of arcuate slots 76a in the base 19. The bearings 23 and 28 and the handle shaft 24 are of-short length to permit movement of the spring 49 across the axis of the movable parts that are. supported thereby, and the bracket members 31, 41 and 53 are of U- shape, to leave a clear space for movement by the springs 37 and 49. Furthermore, this U-shape construction of the bracket members 41 and 53, together with their recesses, which radiate from their central portions (see Figs. 7 and 9) permits the ready assembly or disassembly of these parts, in that such brackets may be inserted into place from the side of the switch by moving them radially into engagement with the grooved portion of the bearing members 23 and 28. The tension exerted by the spring 49, through the pinsI 38 and 51, serves to hold the recessed central portions of these brackets into close-fitting engagement with the grooved bearing members 23 and 28. The pins 34, 38 and 51 are cach grooved adjacent to their ends in substantially the manner indicated in Fig. 15, so thatsuch end grooves will engage their respective associated brackets to prevent vertical movement by the pins.

Referring now more particularly to Fig. 17, a main circuit 77`is controlled by the running switch 79. The running switch 79 prlmarily controls the supply of current to a starting winding 81 of a motor and a running winding 82 thereof, but only indirectly controls the flow of current to the former winding. l/Vhen the running switch 79 is closed, it completes the circuit through the coil and the winding 82. When starting, the switch 42 is also closed, and the circuit through the starting winding 81 is complete.

Upon the closure of both the starting switch and the runningswitch, current'is supplied to both windings 81 and 82. The differential magnetism lof the coils 69 and 70 is then sufficient to maintain the armatures 71 in the position illustrated in Fig. 16, and a high temperature-coefficient resistance 84 is provided in the shunt circuit 78. After current has been directed through ythe shunt circuit and coil- 69 for a short time, the resistance offered by the element 84 increases by reason of the heating thereof and causes more current to flow through coil 70, thus reducing the holding force exerted by the magnet 68 and permitting the spring 58 to move the starting switch 42 (bracket 41) to open position, as above described. The starting switch will, therefore, notv be held closedV for a period sufficient to cause injury to the motor that the apparatus is designed to co-ntrol.

Fig. 18 shows, in detail, the relation of the coils 69 and 70 too the armatures 71 and 74. When the starting switch is closed and the armature 71 moved to the position shown in Fig. 16, the running switch is caused to close as above. explained. The circuit through the coils 69 and 70 is then complete, causing the armature 71 to be retained in the said position until the resistance 84 becomes heated and the flow of current therethrough reduced. This causes an increased flow of current through the coil 70. The flow of current through the coil 69 being reduced and that through coil 70 increased, and the coils being energized in opposite directions, the differential therebetween that creates a magnetic flux through the core during starting, is reduced a sufficient amount to permit the spring 58 to open the starting switch against the magnetic force exerted upon the armature 71. The circuit through the coil 69 and the starting winding 81 is then broken, leaving only the coil 70 effective. The coil 70, being in series with the main winding 82, then acts as an ordinary overload coil and, owing to the remote position then occupied by the armature 71, any magnetic force set up around the core 86 will be exerted mainly upon the armature 74 against the tension of a spring 63a, thus moving the Varmature 74 against the latch lever 62a and the tension of the spring 63 to free the running switch (running switch 7 9--bracket 53) from the lever 62 and permitting the switch to be moved to open position by the tension spring mn.

49, as above described.

I have, therefore, provided means for insuring that the running switch shall not be maintained in closed lposition so long as an overload obtains on the circuit.

Vhile the device has been described in its application to an J:L ,lteinating current motor, of the induction type, it may be employed in in connection with various other classes of apparatus wherein primary and secondary l0 circuit conditions exist.

I claim as my invention:

l. The combination with a starting winding and a running winding, of means for closing the circuit of the starting winding,

means for closing the circuit of the running winding, and means controlled by conditions in one circuit for effecting an opening of the starting winding circuit after the circuit of the running winding has been closed.

2. The combination with a starting winding, and .-a runningv winding, of means for closing the circuit of the starting winding,

means for closing the circuit of the run-` ning winding, and means controlled by conditions in one circuit for effecting an int-erruption of the starting winding circuitxwithin a short time after it has been closed.

3. The combination with a main circuit and a shunt circuit, of a switch for controlling the main circuit, a switch for controlling the shunt circuit, means for closing the second named switch, and means responsive to the current in the shunt circuit for normally causing an opening movement of the said second named switch after a short `period of vtime `following its closure.

4. The combination with a main circuit, and a shunt circuit, of a switch for control- 40 ling the main circuit, a switch for controlling the shunt circuit, a common means for closing the switches, and means responsive to the current in the shunt circuit for normally causing an opening movement of the '45 second named switch after a short period ot time following its closure.

5. The combination lith a main circuit and a shunt circuit, of a switch for controlling the main circuit, a switch for controlling the shunt circuit, means for closing the switches, and means responsive to the current in the shunt circuit for normally causing an opening movement of the second named switch after a short period of time following the closure of the said switches.

6. The combination with a startin winding and a running winding, of a switch for controlling the circuit through the starting winding, means for closing the switch against tension, means controlled by conditions in the circuit through such switch for holding 'it closed and means normally el'ective after a short period of time for rendering said holding means ineffective.

7. The combination with a starting winding and a" running winding, of a switch for controlling the circuit through the starting winding, means for holding the switch losed and means controlled by conditions in the circuit through the switch and normally eective only after a time interval for rendering the said holding means ineffective.

8. The combination with a switch for controlling a shunt circuit and a switch for controlling a main circuit, of a common means for closing the switches, means for holding the switches closed, means governed by predetermined conditions in one of the' circuits for releasing one of the switches, and means governed by other predetermined conditions in one of the circuits for releasing the other switch.

'9. The combination witha starting switch and a running switch, of a lever manually operable to close the switches, means for disengaging the starting switch from the said lever, means for returning the starting 4switch to open position independently of the lever, means controlled by conditions in the circuit for effecting` an opening movement of the running switch and means for automatically returning the said lever to its off yposition when the said running switch is opened. l

10. The' combination with a starting switch and a running switch, of a common means including -a handle for effecting a substantially simultaneous closing movement thereof, means controlled by conditions in its circuit, for effecting an opening movement of the starting switch, means carried by the running switch for maintaining the handle in its closed position, means controlled by conditions in the circuit of the running switch for ei'ecting an opening movement thereof, and means for returning the handle to its open position when the running switch has been opened.

11. The combination with a starting switch and a running switch, of a main spring, of a handle for closing the starting switch against the tension of the s ring, a yielding connection between the han le and the starting switch, ayielding connection between the starting switch andi the main switch, whereby the main switch is placed under tension to effect a closinr movement thereof when the starting switcli is closed, means for disengaging the handle from the starting switch whenA in its closed position to permit the main spring to return the starting switch to open position and to reverse the direction of tension upon the running switch, a latch for holding the running switch closed, and means controlled by conditions in the running switch circuit for tripping said latch.

l12. The combination with' a starting switch and a running switch, of a sprin a handle for closing the starting switc against the tension of the spring, a'yieldin' connection between the starting switch an the running switch, whereby the running switch is placed under tension to eii'ect a closing movement; thereof when the starting switch is closed, means for disengaging the handle from the Jstarting switch when in closed position, to permit the spring to return the startin switch to open position and to reverse the (rection of tension upon the running switch, a latch for holding the running switch closed, means controlled by conditions in the circuit of the starting switch for holding it closed against the tension of the said spring, and means controlled by conditions 1n the running switch circuit for tripping said latch.

13. The combination with astarting switch and a runnin switch, of a spripg, a handle for closing tiie starting 'switch against the tension of the spring,x a yielding connction between the starting switch and the running switch, whereby the running switch is placed under tension to effect a closing movement thereof when the starting switchv is closed, means for disengaging the handle from the starting switch when in closed position, to permit the spring to return the starting switch to open position and to reverse the direction of tension upon the running switch, a latch for holding the running switch closed, and means for either manually or automatically tripping said latch. l

14. The combination with a starting switch and a running switch, of a spring, a handle for closing the starting switch against the tension of the spring, a yielding` connection between the handle and the starting switch, 'a yielding connection between the starting switch and the running switch, whereby the running switch is placed under tension to effect a closing movement thereof when the starting switch is closed, means for disenga-ging the handle from the starting switch when in closed position, to permit the spring to return the starting switch to open position and to reverse the direction of tension upon the running switch, a latch for holding the runnmg switch closed, and means controlled by conditions in the'running switch circuit for tripping said latch, the first named yielding connection being placed under tension upon opening movement of the starting switch and serving to return the handle to offv position when the running switch is opened.

15. The combination with a main switch,

of an auxiliary switch connected in shunt relation to 'the circuit of the main switch, means for closing the switches, `and means controlled by conditions in the shunt circuit for normally effecting an opening movement of the auxiliaiyeswitch within a relatilvely short time a r' the same has been c OSC 16. The combination with a main switch, of an auxiliary switch connected in shunt relation to the circuit of the main'switch, means for closing the switches, means contro-lled by conditions in the shunt circuit for normally effecting an opening movement of the auxiliary switch within a relatively short period after the same has been closed, and means controlled by conditions in the circuit of the main switch fc-r effecting an opening movement thereof. p

17. The combination with a starting switch and a running switch, of a spring for normally biasing the starting switch to open position,`a handle for closing the starting switch against the tension of the said spring, a magnet in the circuit of the starting switch for holding it closed against the tension of the said spring, and a tension connection between thc starting switch and the running switch whereby the ruiming switch is biased toward the position occupied by the starting switch.

18. The combination with a starting switch and a running switch, of a spring for normally biasing the starting switch to open position, a handle \for closing the starting switch againstthe tension of the said spring, a magnet in the circuit of the starting switch for holding'it closed against the tension of the said spring, and a tension connection between the starting switch and the running switch whereby the running switch is biased toward the position occupied by the starting switch, a latch normally biased into engagement with the running` switch to maintain it in closed position, and an electromagnet in the circuit of the running switch for tripping the latch upon the occurrence of an overloadin the said circuit. 4

19. The combination with a starting switch and a ruiming switch, of a spring for normally biasing the starting switch to open position, a handle for closing the starting switch against the tension of the said spring, a magnet in the circuit of the starting switci for holding it closed against the tension of the said spring, a tension connection between the starting switch and the running switch whereby the running switch is biased toward the position occupied by the starting` switch, a latch normally biased into locking engagement with the running switch to hold it in closed position, manually operable means for tripping the latch, and means controlled by conditions in the circuit for automatically tripping said latch.

20. The combination with a starting switch and a running switch, of a handle for closing the switches, means controlled by conditions in the starting switch circuit for automatically effecting an opening movement thereof, and mea s ,for effecting an o ning movement of t e running switch w en the handle is moved to oif position.

21. The combination with a movable switch member, of an actuating member- 4tromagnet 4ineffective to hold the actuating member in advanced position.

22. The combination with a m'ovable switch member, of an actuating member therefor, an armature connected to the actuating member, a latch for holding the movable switch member in advanced position, an armature for effecting the tripping of the said latch, an' electromagnet for cooperating with the said armatures, and means controlled by conditions in the circuit or selectively directing magnetic` iux from the said magnet through the said armatures.

23. The combination with a starting winding and a running winding, of means for closing the circuit of the starting winding, means for closing the circuit of the running winding, and means controlled by conditions in either circuit for eiiecting an opening of the starting winding circuit after the circuit ofthe running winding has been closed.

24. The combination with a starting wind' ing and a running winding, of means for closing the circuit of the starting winding, means for closing the circuit of the running winding, and means controlled by conditions in both of the circuits for effecting an opening of the starting winding circuit after the circuit of the running winding has been closed. o 25. The combination with astarting windlng and a running winding, of means for closing the circuit of the running winding, and means controlled by conditions in either circuit for effecting an interruption of the starting winding circuit within a short time after it has lbeen closed. I 26. The combination with a starting winding and a running winding,of means for closing the circuit of the running winding, and means controlled by conditions in both circuits for effecting an interruption of the starting winding circuit within a short time after it has been closed.

27. The combination with a switch for controlling a shunt circuit and a switch for controlling a main circuit, of a common means for closing the switches, means for holding the switches closed, means governed -by predetermined conditions in both circuits for releasing one of the switches and means governed by other predetermined conditions v means for closin in one of the circuits for releasing the other switch.

28.` The combination with a switch for controlling a shunt circuitv and a switch for controlling a main circuit, of a common the switches, means for holding the switc es closed, means governed by predetermined conditions in either circuit for releasing one of the switches, and

' means governed by other predetermined conditions in one of the circuits for releasing the other switch.

29. The combination with a main switch, of an auxiliary switch connected in shunt relation to the circuit of the main switch, means for closing the switches, and means controlled by conditions in a circuit controlled by one of the switches for normall eiecting an opening movement of the auxi iary switch within a relatively short time after the same Ahas been closed.

30. The combination with a main circuit and a shunt circuit, a switch for the main circuit, and a switch for the shunt circuit, of a pair of parallel connected electromagnetic devices responsive to conditions in the 4circuits connected thereto, one of the said devices serving to control the main switch and the other serving to control the auxiliary switch. b

31. The combination with a main circuit and a shunt circuit, a switch for the main circuit, and a switch for the shunt circuit, of an electromagnet for controlling the said switches and having two parallel connected coils, and means responsive to current conditions of the circuit including one of the coils for controlling the operation of the electroma et.

32. The combination with a main circuit and a shunt circuit, a switch for the main circuit, and a switch for the shunt circuit, of an electromagnet for controlling the said switch and having two parallel connected coils, and means responsive to current lconditions of the circuits including the coils for controlling the operation of the electromagnet.

33. The combination with a main circuit and a shunt circuit, a switch for the main circuit, and a switch for the shunt circuit, of an electromagnet for controlling the said switches and having two parallel connected coils and means responsive to current conditions of either circuit including the coils for controlling the operation of the electromagnet.

In testimony whereof, I have hereunto HUBERT K. KaANTz.

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