US914356A - Electric-circuit controller. - Google Patents

Description

H. W. LEONARD. ELECTRIC CIRCUIT CONTROLLER. APPLIOATION FILED APR. 6, 1906.

914,356. Patented Mar. 2, 1909.

' P J J N c I g a c d a Q 0 6 I O! 0 M P J J N 1 a" I B YINVENTOR I rm/my current.

HARRY WARD LEONARD, OF BRONXVILLE, NEW YORKv ELECTRIC-CIRCUIT G ONTBOLLER.

No. 914,356. Original application filed November 30, 1 901,

Specification 0: Letters Patent.

Serial No. 237,653. Divided. and this application filed. April 6, 1906.

' Serial No. 310,200. ,7

Patented March 2, 1909.

To all whom it may concern:

Be it known that I, HARRY WARD LEON- ARD, a citizen of the United States, residing at Bronxville, in the county ofWestchester and State of New York, have invented cer tain new and useful Improvements in Electric-Circuit Controllers, of which the following is a full, clear, and exact specification.

This application is a division of my pending application filed November 30, 1901, Serial No.- 84,188,- renewed December 20, 1904, Serial No. 237,653, granted April 10, 1906, Patent No. 817,719, and relates generally to controlling switches and has a articular application to motor starting r eostats, or rheostats employed with electric motors or otheargr ectrical translating devices, in which the resistance is employed not for regulating the energy supplied to the motor or other translating device, but mainly for gradually raising the energy at the terminals 'of the translating device to the full electromotive force.

My invention is also of importance where regulating resistances are used and to prevent their improper operation. v

I have. found inpractice that such rheostats are fre uently damaged by holding or permitting t 1e contact lever to remain on the initial or starting contact or contacts near the same with all the resistance of the rheostat or a considerable portion thereof in circuit. I have also found that operators frequently close the circuit at the initial or starting contact of the nheostat and then return the lever to the idle position, thus drawing an are at the initial contact. This also damages the rheostat. I have also found that operators sometimes close the main circuit when the resistance controlling device, which 'might he used as regulator, is in an intermediate position. This of course allows an excessive and damaging flow of The main object of my invention is to devise a starting rheostat or controller, or to provide the resent type of rheostat with a controlling evice, which will prevent this im roper handling of such. rheostats.

though of importance in connection with hand controlled rh'eostats, my invention is also of advantage in connection with automatically operated rh'costats.

The full torque current is the current which the motor takes in developing its full rated horsegip'ower. Instarting any motor, it becomes necessary to produce a torque larger than thatdue to the full tor ue current because the motor and the load rave to be accelerated, and during the period of acceleration, a larger current will he required than that necessary after the motor has been accelerated to full speed. In the manufacture of motor starting rheostats, it is conimon practice to have such a resistance in the'rheosta-t that the current which will flow when the motor is at rest and the first contact is made at the rheostat, will be fifty per cent. larger than the current taken by the motor when producing its normal full torque. In otherwords, this starting accelerating current is fifty per cent. larger than the full torque current, that is, it is one hundred and fifty per cent. of the full torque current;

In order to prevent the burning at the ini tial contact of the rheostat, due to the closing of the circuit upon insufficient surface, or due to the backward movement of the contact lever after making the first contact, which results in the formation of an arc due to the 'full elcctromotive force and one hundred and ii'fty per cent. of the full torque current (when the motor has no counter electromotive force), the rheostat should be provided with an auxiliary switch, by which the circuit is quickly closed upon an ample surface and which switch will open the circuit with. a snap-action when the contact lever is returned to the initial position. This auxiliary switch should be beyond direct hand control in 0 ening and may be mechanically or electrical y controlled by tho rheostat contact lover or controlling switch.

In my original application, I have dis closed two forms of my invention in which the auxiliary switch ismechanically controlled. The .rcsent application relates more particular Y to forms in which the control of the auxiliary switch is by electrical means. 1

My invention includes various other improvements and advantages which will be understood from the followingdcscription and accompanying drawings.

Inthe accompanying drawings, Fi ure 1 is a diagrammatic View of one form 0- m invention' and Fi 2 is a similar view 0 an other form of m'* invention.

Referring to 1g. 1, there 18 mounted on a a, to which the sections suitable base (not shown) a series of contacts of the resistance a are connected. This resistance, it will be understood is arranged in any suitable manner beneath the base or within a casing, and the sections of resistance will be insulated from each other and in some instances proand in this instance is started by solenoids O and 0 whose cores are connected to the arms of the hammer, and d is the spring for throwing the hammer after it passes the center of equilibrium, although in this arrangement the spring might be dispensed with, since the movement of the cores will be very rapid and move with increasing s eed. The circuit connections are from con uctor P to switch C, to lever B, resistance a and motor M to the conductor N, the field of M being in shunt from lever B around the resistance and motor armature. Coils O and O are. connected in shunt relation between contacts 0 and 0 and conductors P and N. Contacts 0 and 0 are located adjacent to the first and second rheostat contacts a respectively, so that in the initial position lever B will bridge the first contact a and contact 0, and in the second position contact 0 and the second contact a will be bridged. The effect of this, is to connect either coil 0 or O in circuit and as shown coilO is in circuit and its core is drawn down and hammer D is tilted to the right closing switch C. If lever B is returned to its initial position, coil 0 will be out out and coil 0 cut in, thus actuating the core of the latter to throw the hammer to the left and open switch C. When lever B is moved to its final position, both coils will be cut out of circuit and spring d will hold switch C in po sition. 'It is thus apparent that the main circuit will be completed, and that the main, current flow will be interrupted at the auxiliarv switchjC, and the sparking which would otherwise take place at the resistance contacts is avoided. A modification of this arrangement is shown in Fig. 2. Here only one coil 0! is employed, and this coilis connected between conductor P and a contact 0 with which the insulatedshort arm I) of lever B makes contact when in contact with any of the rheostat contacts a from the-second to the'fmal contacts, but not when in' contact with" the initial contact. Switch C (shown as a brush switch) is provided with a rod 2 which breaks the on carbon con- 0 and stirrup 2 tacts z. This switch is mounted on a vertically sliding rod 2 provided at its upper end with a stirrup 2? within which works a foot 0 securedto the lower end of rod 0 projecting from the core or plunger of coil 0 The vertically sliding rods 2 and 0 work in suitable guides, and the lower end of rod 2 is rectangular and works in a correspondingly sha ed bearing to hold switch C in alinement wit its stationary contacts.

As shown in Fig. 2, the rheostat lever B is in its second position, and the circuit to coil 0 is closed and. its core is drawn up and switch Cis closed. If now the operator returns leverB to the initial position, coil 0 will become "demagnetized and its plunger will drop striking a blow to the stirrup, the force of which and. the tension of the brush switch, will drive theswitch downward and 0 en the circuit to the rheostat and motor. V hen the lever B is moved forward, closing the circuit again at contact 0 the plunger of coil 0 will rise, and through the engagement of foot switch C will be closed.

It will be noted that I have indicated a motorM in the drawings having a shunt field winding, and that the supply cricuit to both the armature and shunt winding is opened by means of the automatic switch in the main circuit. 'Also, that when the circuit is opened,

the armature and field are closed on them-' selves, giving aclosed circuit for the field discharge.

It is evident that my invention may be embodied in various forms of construction and that I am not limited in the scope thereof except as indicated in the following claims.

Having thus described my invention, Tdeclare that what I claim as new and desire to secure by Letters Patent, is,-- I

1 The combination of a rheostat, a switch, an electro-magnetic actuating device there for, and means whereby said switch is closed and opened by the forward and backward movement of the movable element of said rheostat at the initial'positions.

2. The combination of a hand operated electric switch, a second switch in series therewith, means for automatically moving said second switch to the closed. or to the openposition com rising electrical controlling means operate by the movement of said hand 0 erated switch.

31' The combination of a rheostat having a movable element for controlling the resistance, a switch in series therewith, means for moving-said switch to the closed or open 0- sition, and electrical contact means control by the position of said element for contFolling said switch moving means.

4. The combination with a rheostat having a movable element for controlling the resistance, of a switch in circuit therewith, an electro-magnetic, actuating device for said switch, and means whereby said switch is exce s limiting positions. Ii

' 5. The combination of a motor riaeostat having a movable element for controlling the resistance, a SWl-tCll in series therewlts, means for moving said switch to the closed or open Cir positions, and electrical contact means controlled bythe position of sa d-element for causing said switch moving means to actuate 1 said switch and complete the circuit and to cause the opening of said switch to interrupt the current flow..

6. The combination of a motor rheostat, a switch for closing the circuit, a control magnet governing its closure, and means for controlling the circuit connections of said magnet dependent upon the return of the resistance controlling element of said rheostat t the initial position. I p

7.. The combination of a motor rlieost-at having a movable element for controlling the resistance, a circuit breaker, a contact engaged by the movement of said element, a coil in circuit with said contact and control ling the closing of said circuit breaker, and circuit connections wl...ere.by said coil is deenergized after said circuit breaker i'as been closed, j i

S. The combination of a motor rl eostat having a movable element'for controlling the resistance, a circuit breaker, a contact engaged by the movement of said element, a

j l l coil in circuit wit said contact and control I ling the closing of said circuit breaker, and

means w? ereby after saidcircuit breaker as been closed tle circuit ofsaid coil may be opened wit? out affecting said circuit breaker.

9. The combination of a supply circuit, an electric motor, a switch for connecting and disconnecting the motor armature to and j from the supply circuit, electromagnetic? means for actuating said switch to connect and disconnect said motor armature to and from the supply circuit, and means whereby said electromagnetic means is automatically deenergiz'ed during normal operation of said motor.

10. The combination of a translating device, a controlling switch, an electromagnetic win ding for effecting the closure of said switch when said winding is energized,

means for holding said switch closed indewndently of said windingafter the switch has been moved to closed position, and means whereby the current in said winding is reduced after the closure ofsaid switch.

11. The combination of-a resistance having a movable element for Varying the resistance, a switch, a coil controlled by the movement of said element for contitolling the closure of said switch, and a second coil controlled by the movement of said element for controlling the opening of said switch.

12. The combination of a resistance-having a movable element for varying the resistance, a switch, electromagnetic means for closing said switch, means controlled by the movement of said element for interrupting the circuit otsaidelectromagnetic means, and auxiliary means for holding said switch closed.

' 13. The combination of an electric motor, an annature resistance, a switch in series with said resistance, a coil for closing said switch automatically, a second coil for automatically opening said switch, and means for insuring the automatic closure of said switch only when a protective amount of resistance is in series with the motor armature.

14. The combination of an electric motor, a switch in series with the motor armature, two actuating coils for controlling the automatic movement of said switch, one of said coils being energized during the closing of said switch and the other of said coils being energized during the opening of said switch, and additional means for maintaining said switch closed.

15. The combination of a supply circuit, an electric motor, an automatic switch in series with the motor armature, a coil for conand connections whereby said coil is connected in series with the motor armature across the supply circuit during the closing period of said switch whereby said coil is subjected to the electromotive force of the supply circuit less any counter electromotive force of the motor armature.

16. The combination of an electric motor, an armature controlling rheostat, an electromagnetically controlled automatic switch, means for controlling .the closing movement of said switch by the movement of thejmo-vable element of said rheostat when moved in the resistance inserting direction, and means controlled by the movement of said element for causing the automatic opening of said switch. y

17. The combination of a supply circuit,

an electrlc motor, an armature resistance, a

sistance, a constant electromotive force supply circuit, an electromagnetic winding, a switch controlled by said windingmlrd means I I said supply circuit,

automatically closable through the agency of for connecting said winding in series with means whereby said first named switch is connected in shunt to said winding.

21. The combination of a constant electromotive force supply circuit, an electric motor, a controlling resistance therefor, an electromagnetic winding, a switch controlled by said winding and adapted to be connected in series with the armature of said motor and in shunt with said winding, and means for said resistconnecting the motor armature,

across the ance, and said winding in series supply circuit.

22. The combination of a constant electromotive force supply circuit, an electric motor, a controlling resistance therefor, an

electromagnetic winding, a switch whose closing movement is controlled by said winding and which switch is adapted to be connected in series with the motor armature and said resistance and in shunt winding, and means for connecting said motor armature, said resistance, and said wind- ?ing in series across the supply circuit.

23. The combination of a constant electromotive force supply circuit, an electric motor, an armature resistance, a manually operated switch, an electromagnetic winding, connections for connectin the motor armature, said resistance, sai switch, and said winding in series in a branch circuit across an automatic switch said winding, and connection whereby said automatic switch, the motor armature, and said resistance are connected in series with each other and whereby said automatic switch is connected-in shunt with said wind- 1n a supply circuit of constant electromotive force, a manually operated rheostat, a switch, said switch and rheostat being in series with each other and with the motor armature across said circuit, and electrical means controlled by the movement of the movable element of the rheostat for controlling the closing and opening of said switch to establish and break the current through the motor armature. v

25. The'combination of an electric motor having a field winding energized independently of its armature current, a manually operated rheostat for controlling the motor armature, a switch for carrying both the ;-through said field winding,

means controlled by with said g 24. The combination of an electric motor,

motor armature current and the current and electrical the movement of the movable element of said rheostat for causing the automatic closing and opening of said switch.

26. The combination of a supply circuit of an electric constant 'ielectromotive force, motor, ai armature controlling rheostat, said rheostat, the motor armature and a field winding oftthe motor bein connected in a closed circuit-,a magnetically moved switch for making and breaking connection between said closed circuit and the supply circuit, and electrical means dependent .upon the movement of the movable element of the rheostat for controlling the opening movement of said switch.

27. The combination of a rheostat having a movable element for controlling the resistance, an automatic switch in series therewith, and: electrical-means operated by the movement of said element for controlling the automatic closing and automatic opening of said switch.

2-8. The combination with a sup ly circuit, of a resistance having a manual y movable element for varying said resistance,. a switch in series therewith, and electrical means for controlling the closing and opening of said switch, said means being controlled by said movable element whereby said switch is closed when said element is manually moved in a direction to reduce resistance and is o ened when said element is moved in a direction to increase resistance.

2-9. The combination of a resistance having a manually movable element adapted to vary the resistance, a switch for controlling the circuit of said resistance, and electricmeans for controlling the automatic closing and automatic opening of said switch, said means being controlled by the movement of said movable element.

30. The combination el a motor, a rheostat for said motor having a manually movable resistance varying element, an automatic. electromagnetic switch, and electric means for causing the manual movement of said element to control the movement of said switch in two directions at the starting position. a

'31.'The combination of a motor, a rheostat for said motor having a movable 're sistance varying element, means for causing an auxiliary electrical contact to be made by the movement of said element to. a certain osition and to be broken'by its movement in a direction to insert resistance, an electroresponsive winding energized independently of the motor operating current and the current in which is affected by the making and breaking of said contact, and aswitch in series with the motor armature controlled by said electroresponsive winding.

the movement of saidielement in a direction.

to reduce said resistance and for. controlling the breaking of said contact; by its movement in theopposite direction, an electrothe current in. which is responsive windln affected by thev ma ring and breaking ofisaid contact, and a switch the closingmovement of which is controlledby said winding.

33. The combination-of an electric motor, a controllin rheostat havin a manually controlled e ement, a switch 1n series with said rheostat, andv electrical means controlled by said element when moved in a direction to insert and in a direction to cut out resistance for causing the opening and closing of said switch independently of the rate of movement of said element.

34. The combination with a rheostat and a movable element for varying the resistance, of a switch for controlling the circuit of said rheostat, and electrical means operated by said element when moved in a forward and backward. direction for respectively controllin the closing and opening movement of saic switch.

35. The combination of a resistance controlling movable element, a switch in series therewith, and electrical means operated by the movement of said resistance controlling element for controlling both the automatic closing and automatic opening of said switch.

36. The combination of a'rheostat having a manually movable element for varying the resistance, a switch for controlling the circuit to said rheostat, and electrical means operated by said element for controlling both the closing and opening movement of" said switch when said element is in position to insert substantially all of said resistance.

37. The combination of an electromotive force producing device, an automatic switch Whose automatic movement is dependent upon a current other than the current passin through said device, a rheostatic movab e element in series with said switch, and a manuall controlled auxiliary contact device functionally-related to said element for controlling the automatic closing and automatic o ening of said switch.

38. he combination of a rheostat having a movable element for varying the resistance, a switch in series therewith, restraining means for holding said switch in closed position, and means controlled by said element (in when substantially all of the resistance is in circuitfor electrically closing said switch.

39. The combination of a rheostat having a movable element for varying the resistance, anv electromagnetic switch in series therewith, restraining means for holding said lectively ener izing said coils.

pendently of the motor current, and a contact at or near the initial position of said element for energizingsaid coil.

41'.. The combination of'a resist'ancecontrolli'n current carryin movable element, said element being adapted to vary the amount ofresistance in circuit but not adapted to interrupt the flow of current, a switch in series with said element adapted to open and close the circuit, and electromagnetic means functionally related to said element for controlling the automatic closing and automatic opening of said switch.

42. The combination of an automatic switch corn rising two actuating coils, a circuit contro ling movable element in series with said switch, and means dependent upon the movement of said element for se- 43. In com inatlon, a motor controller, a switch, and means'for automatically closing and opening said switch, said means comprising a magnet for opening said switch to control the motor circuit, and connections whereby said magnet is ener ized only when the controller is moved bac ward to a cer-.

ment, and means whereby said magnet isj energized only when the controller in its backward movement reaches a predetermined osition. 4

45. n combination, a controller for an electric motor, a switch through which the motor current is supplied when the controller is in a predetermined position, and means for automatically closing and automatically opening said switch comprising a magnet for opening said switch, and means whereby said'magnet is energized only when the controller in its backward movement reaches a predetermined position. 7

46. The combination of a rheostat having a movable element for controllin the resistance, an electromagnetic switc in series therewith, manually controlled. auxiliary electric contact means functionally related to said element for controlling the automatic movement of said element to a protective position.-

47. The combination of an electric motor, an armature controlling rheostat, an electromagnetically controlled automatic switch, means for controlling the closing movement of said switch by the movement of the movable element of said rheostat when moved in the resistance inserting direction, and auxiliary electric contact means functionally related to said element for causing the automatic opening of said switch.

48. The combination of a motor, -a motor controller having a movable element manually movable in both directions, a movable circuit closing element, means for automatically moving said element to close its circuit, said means comprising a magnet for controlling the closing movement of said element, and means whereby said magnet is energized to cause the closure of said element only when the controller in its backward movement reaches a redetermined osition, the connection of said closing coil eing such that said coil is energized inde pendently of the motor armature current.

In testimonywhereof, I affix my signature-

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