US901424A - Electrically-controlled switch. - Google Patents

Description

A. s; GUBITT. ELEGTBIGALLY GONTBOLLED SWITCH.

APPLICATION FILED APBJB, 190a.

Patented 0013. 20, 1908.

Witnesses I 5 41 Kin-9 UNITED STATES PATENT OFFICE.

AROHIBALD S. CUBIIT, OF SGH'ENEG'IAIIY, NEW YORK, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OI NEW YORK.

ELECTRICALLY-CONTROLLED SWITCH. r

To all whom it may concern:

Be it known that I, AnoHmALn; S. Contra, a subjectof the King of Great Britain, residing tudy, State of Nw Yorlohave invented certain new and useful. Improvements in Electrically-ControlledSwitches, of which the following is a specification.

In connection with certain forms of electrical apparatus electrically controlled switches areused in which a current carrying coil is' employed 'for maintaining the at which the holding coil releases may bevaried by means operable from a distance.

It is an object of my invention to provide means for satisfyingthis need in a simple and ellicientmanner.

My invention is particularly adapted for use in connection with relays in which a movable core is by some means moved to a certain position and held there-at by the magnetizing effect of-afholding coil. Such relays are often employed in connection with s stems-of coutrol for dynai'no elcctric Ina-- c nnes in which a plurality; of electricallyi controlled switches are arranged ,to operate in succession .for the purposeof eflecting certain desired connections in the circuits of the controlled apparatus. For example, in certain systems of motor control now wellk nown to those skilled in thisart the resistance interposed in the motorcircuit on starting is automatically removed sectio rby-section by means of a plurality of electrically-controlled switches which operate successively under the control of a so-ealled notching-relay which interrupts the actucircuit for the switches aft'er theopcratron of each switch and-maintains said atin circuit interrupted as long as the current in the motor circuit exceeds a certain-"value. It is to these relays that my invention isespecially applicable, and the needfor'itferises especially where, because of inequalities 'in the load upon the controlled apparatus','it is Specification of Letters Patent.

Application filed April 22, 1908. Serial No. 428,628.

at Schenecta dy,' county of Schenec-,

Patented on. 20, 1908.

desirable to vary the llinit of current permissible in the circuits of the controlled apparatus and thereby regulate the rate of acceleration. I

Systems of control in which the cutting out of the starting resistance in the motor circuit takes place automaticaly are now used to a large extent in the operation of electrically-driven;vehicles, such as cars and locomotives, and it is in this line of work that my invention is especially useful.

In the following description and in the drawing I have described and illustrated a notching relay having my invention embodied therein, but I do not wish to be understood aslilniting it to this application since it may be used in many other connections, as will be obvious to those familiar with this art.

The drawing illustrates in front elevation a notchi ng relay hai ing my invent-ion incof Ora-ted therein. i

Re erring to the drawing, 1' is a back plate of any su1tiiblje insulating material upon which are mounted the various parts of the device;

2 is the iron? frame: of the rela secured in any suitableunannerto the baci plate 1,

within which frameis an actuating coil 3 of insulated wire and a holding coil 4 of heavy conductor. Arranged formovement within the coils?) and 4 isa core 5 of magnetic material carrying near its lower end a- 'steel" contact disk fiwhich when the core is in the position shown bridges fixed contacts 7 and 8 of magnetic material. The contact disk 6 is slidingly arranged upon an extension 9 of the core 5 between a shoulder 10 ands sprin 11. Coils 12 and 13surround the fixe contacts 7 and 8, res ectively, and are connected in series with 't ese contacts and serve to (produce a magnetic field which retains the isk 6 in engagement with the contacts 7 and 8 durin the first part of the upward movement 0? the core, thereby delaying the o nm of the contacts and also giving a quic brea A fixed core 15 of magnetic material is screwed into the top of the frame 2, being held in position by a set screw '16. This core protects into the own in the the coil 3 as s di i iviii g i the movable core 5 rod 1'1 extends upward from and is connectedat its ,upper end to the movable member 18 of a dash-pot 19. This dash-pot allows the movable core to rise freely but retards it in its downward movement. I

The parts of the relay so far described,

- except for a slight change in the rod 17,

. herelnafter mentioned, may be of any suit! able and well-known form.

Secured in any suitable manner, either to the frame 2 or directly to the back plate 1,

, is a frame 21' in which at 22 is pivoted a lever 23 through a hole in which the upper reduced portion 24 of the rod 17 freely passes, as clearly shown in the drawin A.

Washer 25 maybe provided on the reduced )ortion 2 1 of the rod 17 between the shouler formed by the larger part of the rod 17 I and the lever 23. The lever 23 carries at its outer end an armature 26 of magnetic mate rial which when the lever is in the position shown in full lines bridges the oles of an phosphor-bronze in order to prevent sticking 1 core 5'."

of the armature to the magnet when the latter is deenergiz'cd. The steel disk 6 and the fixed contacts 7 and 8' may besilver plated on their cooperating surfaces for the same reason and in order to insure good electrical contact at these points The last two mentioned expedient's'are well-known.

The operation of the device is as follows: When current passes through the actuating coil 3, which may be connected in series with the coils l2 and 13 and the contacts 7 and 8 as shown, the core 5 rises into the magnetic field produced, and if the the et 27 1s deiingerized-the lever 23 will be 1i (1 to the posltionshown in dotted lines. The air gap between the top of the movable core 5 and the fixed core 15 will then be small and ajcurrent of a certain value in the coil 4will be required to hold the core in this raised" position after the disk 6. has broken engagement with contacts 7"and 8, thereby interrupting the circuitthrough the coil 3. If, however, the magnet 27 is energized prior to the energization ofthe actuatingcoil 3, the armatilre lti will be held down in engagement with the magnet and thellever '23 willbe enga ed by the washer 25 and will serve tostop teupward movement 'of the The-core 5 will, therefore, have a new limit-to its upward movement'and'the gap existing after'operation between the top ofthe core 5' and the bottom of the core 15 willbe greater than'it was when the core was free to .rnove ,upward its maximum amount unimtpcded by the lever 23. By increasing in is way the ga which exists between thscoresaand-law the'corefi is in its upper position, the permeability of the magnetic circuit of the holding coil 4 is decreased and a larger current is required in the coil 4 to hold the core 5 in its, upper position. This means that when a relay equipped as shown is used asa notching relay 1n a system of control, it may be controlled from a distance by energizing or deenergizin the ma net 27 and will give two limits ey ond w ich if the current in the motor circuit is increased, further cutting out of resistance will be prevented. By locating the switch which controls the energization of the coil 28 near the point from which the operator controls the system the change is easily made from operation at one current-limit to operation at the-other.

What I claim as new anddesire to secure by Letters Patent of the United States, is,

i 1. In a switch, a current carrying coil, a core movable in the field thereof, means for moving said core into the field of said coil-, and means operable from a distance for varying the permeability of the magnetic circuit of said coil.

2. In a switch, a current carrying holding coil, a core movable in the field thereof, means foamoving said core into the field of said holding coil, and means operable from a distance for varying the permeability'of the magnetic circuit through the movable core.

3. In a relay, a current carrying actuating coil, a current carrying holding coil, acor movable in the, fields of said coils and ar-,

ranged to be moved by" said actuating coil and held by said holding coil, and means operable from a distance for varying the permeability of the magnetic circuit of the holding coi 4. In a relay, a current carrying actuating coil, a current carrying holding coil, a core movable in the fieldsof said coils and arranged to be moved b said actuating coil.

and held by said holding coil, a fixe lcore of magnetic material toward which the movable core .moves, and'ineans operable from a distance for varyin the "ap existing between the movable an 'fi'x movable core has been moved to its extreme position towardssaid fixed core.

6. In a relay, a current carrying actuating coil, a current carryingholding' coil, :1 core of magneticmaterial movable in the fields of sai coils and arranged to be moved by said actuating coil and coil, a fixed core of ma etic material toward which said movab core rnovm, and

cores when. the

eld by said holding of said coils and arranged to be mov means operable from a distance for varying the limitof movement of the toward the fixed core.

.7. In a relay, a current carrying actuating cull, a current carrying holding coil, a core of magnetic material mbvable in the fields of said coils am, arranged to be moved by said actuating coil, a fixed core toward which said movable core moves, and electromagnetieally operated means for varying the gap existing between said movable and movable core fixed cores after said movable core has been moved to its extreme position toward said fixed core.

' 8. In a relay, a current carrying actuating coil, a current carrying holding coil, a core of magnetic material movable in the lds y said actuating coil and held by said'holding coil, a fixed core of magnetic'material toward which said movable core moves, and

elect-romagnetically operated means for .varyingthe limitof movement of said movthe limit of movement of said movable core toward said fixed core. y

In Witness whereof, I have hereunto set my hand this 21st day of April, 1908. I

ARCHIBALD. S. CUllllT. Witnesses I BENJAMIN 1-5. Hum, HELEN ()nrom).

coils, contacts opened by said core in

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