US914355A - Electric-circuit controller. - Google Patents

Description

H. W. LEONARD.

ELECTRIC GIBGUIT CONTROLLER.

APPLICATION TILED APR. 6, 1906.

914,355. Q Patented Mar. 2, 1909.

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INVEIVTQR ATTORNEY n15: NORRIS PETERS ca, WASHINGYON, mc.

n. w. LEONARD. ELECTRIC 01301111 CONTROLLER.

APPLICATION FILED APR. 6, 1908.

Patented Mar. 2, 1909.

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ATTORNEY rm: Nomws PETERS H. w. LEONARD. ELEGTBIG GIBGUIT GONTROLLBB. APPLICATION FILED APR, 6, 1906.

914,355. Patented Mar. 2; 1909.

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WITNESSES. MIVEIYTOH My fiwwz HARRY WARD LEONARD, OF BRONXVILLE, NEW YORK.

ELECTRIC-CIRCUIT CONTROLLER.

Specification of Letters Patent.

Patented March 2, 1909.

Original application filed November 30, 1901, Serial No. 237,653. Divided and this application filed April 6, 1906.

Serial No.

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 of Westchester and State of New York, have invented certain new and useful Improvements in Electrio-Circuit Controllers, of which the follo wing is a full, clear, and exact specification.

This application is a division of my application 'led November 30, 1901, Serial No. 84,188 renewed December 20, 1904, Serial No. 237,653, and granted April 10, 1906, Patent No. 817,719 and relates generally to controlling switches and has a particular application to motor starting rheostats, or rheostats employed with electric motors or other electrical translating devices in which the armature 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. I have found in practice that such motor starting rheostats are frequently damaged by holding or permitting the contact lever to remain on the initial or starting contacts, 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 rheostat and then return the lever to the idle position, thus drawing an are at the initial contact. This also damages the rheostat.

The main object of my invention is to devise a starting rheostat or controller, or to provide the present type of starting rheostat with one or more controlling devices, which will prevent this improper handling of such rheostats.

The full torque current is the current which the motor takes in developing in a full field its full rated horse power. In starting any motor, it becomes necessary to produce a torque larger than that due to the full torque current because the motor and the load have to be accelerated and during the eriod of acceleration, a larger current will "e re uired than that necessary after the motor has been accelerated at full speed.

In the manufacture of motor starting rheostats, it is common practice to have such a resistance in the starting rheostat that the current which will flow when the motor is at rest and the circuit is made to start the motor, will be fifty per cent. larger than the current taken by the motor when producing its normal full torque. In other words, 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 initial contact of the rheostat, due to the closing of the circuit upon insufiicient 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 electromotive force and one hundred and fifty 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 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 opening and may be mechanically or electrically controlled by the rheostat contact lever or controlling switch.

In my original application, I have disclosed two forms of my invention in which the auxiliary switch is mechanically controlled. The present application relates more particularly to forms in which the control of the auxiliary switch is by electrical means.

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

Figure 1 is a diagrammatic view of one form of my invention; Figs. 2 to 5 inclusive, are similar views of modified forms; and Fig. 6 is a perspective view indicating the construction of certain parts.

Referring to Fig. 1, there is mounted on a suitable base (not shown) a series of contacts a, to which the sections 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 provided with means for absorbing the local energy developed therein. B is a switch in the form of a rheostat contact lever pivoted on the base. In this form of my invention, the movement of the rheostat lever B controls a coil which actuates a plunger or controls a plunger, to trip a spring actuated switch, and which switch may be one element of a douple pole circuit breaker.

The auxiliary switch of Fig. 1 is an automatic circuit breaker of the type shown in the patent to Leonard and Ball, No. 705,102, granted July 22, 1902. G and G are independently movable switches cooperating with stationary contacts, between which is connected an overload coil H, said switches and coil being connected in series between conductors P and N. Switch G in this form serves as the auxiliary switch, and its opening movement in response to the backward movement of the contact lever at the initial position is controlled by fine wire coil H,

which is connected across conductors P and N through a suitable resistance. The coil H is controlled by an automatic switch which is preferably a double arm switch S and s, pivoted on a common pivot and provided with a spring tending to throw them toward each other. Switch S makes contact with a spring clip connected with coil H, and which clip holds it in position, while arm 5 makes contact with a button connected to conductor N. This arm is held by a latch s which is tripped by the action of the core or plunger of coil S. Arm .9 is not provided with an operating handle and is arranged to be moved onto its contact by arm S. The coil S for controlling this switch is connected across the first resistance contact or the rheostat and a blind initial rheostat contact. A no-voltage magnet F for holding the rheostat arm in its final restrained position is shown connected in series with a field winding of the motor M. A yieldable switch B is shown carried by the arm B and in final position this switch engages the fixed contacts as, r and thus shunts the main current from the resistance contacts of the rheostat. The plunger of coil H is normally down, and when raised by the passage of an overload current through the coil, the latches of both switches G and G will be tripped as is customary in double pole circuit breakers and as in the Leonard and Ball patent above referred to. The plunger of coil H is normally up during running condition, and upon the occurrence of no voltage, or when this coil is denergized, its plunger will fall and trip the latch holding switch G closed and so interrupt the main circuit.

The construction of suitable automatic switches is indicated in Fig. 6. Here each switch G, G is shown as carried by the pivtomatic switch S, .9.

oted part 9 and each part having a handle for manual closing. Each part 9 has a projection g adapted to be engaged by a latch g for holding the switch in a closed position. The latches g of both switches are controlled by the coil H and its core h. hen the core is raised, due to the large current passing in coil H, both switches will be tripped by reason of the cross piece It engaging the extensions g 0 connected to the latches. The switches will then be opened, as by the force of springs g and the rods 9", since the latter are drawn outward by the tension of the springs, and which rods engage the surfaces 9 on the switches. W hen core h of the coil H is allowed to fall by reason of the reduction or absence of current in H, switch G will be opened. This is accomplished by the engagement of the cross piece h of the core h when falling with the extension 9 connected to latch g and so move the latch to release switch g which will then be opened by the force of the spring 9 It will be noted that the starter of Fig. 1 has no open circuit point. To start the motor or other translating device, the operator first closes the switch G, then switch arms S and s are closed, and then the operator holds down the plunger of coil S and closes switch G. It will be seen that when this is done the circuit connections will be as indicated, that coil S is energized, and that if the operator permits lever B to remain on the initial or lind contact and lets go of the plunger of coil S, that plunger will release switch arm 1 s and open the circuit of coil H, which in turnwill drop its plunger and efiect the opening of switch G and the circuit to the rheostat and translating device. If the operator moves lever B to its final position, as he should do, it will be seen that the circuit to coil S is opened the instant lever B leaves the initial contact, and that switch arm .9 will remain locked until lever B is returned to its initial position, whereupon coil S becoming energized will trip latch s and cause the opening of the circuit of coil H, which in turn will effect the opening of the main circuit by the quick acting switch G. The circuit is thus opened at the outside switch automatically, and arcing at the rheostat contacts is avoided. The circuit will always be protected from overload by the action of overload coil H and will be protected from 110-voltage by the action of coil H which upon abnormally low voltage, or upon failure of voltage, will release its plunger to open switch G Also when the arm B is in final position, the magnet F will act to protect the circuit from no-voltage conditions by its release of the arm B.

In Fig. 2, the coil H is connected across the circuit in series with switches G, G, the rheostat, the translating device, and the au- The construction is otherwlse the same as in Fig. 1. W 1th tms construction the tripping of latch s by the upward movement of the core of coil S will cause the opening of the main circuit directly at switch 8.

Instead of connecting the auxiliary switch of Figs. 1 and 2 as shown, it might be arranged to close a normally open shunt around coil H. This is shown in Fig. 3. When current passes through the coil S, its core is raised and the switch carried thereby closes the shunt around coil H. Its core then drops and opens switch G.

The switch and coil might be arranged as a time switch by placing an iron or nickel resistance between the initial and first resist ance contacts of the rheostat, so that coil S will be connected as a shunt to an initial resistance step of variable resistance, which in this case would act automatically to increase its resistance, due to its high temperature coeflicient, and send an increasing current through coil S. This is illustrated in Fig. 4, the resistance T having a high temperature coefiicient. When redeterminable current passes through coil and raises its core, the switch in circuit of H is opened. Instead of such a resistance, a time fuse might be employed, which when fused would cause the current to flow through coil S. This modification is shown in Fig. 5, in which the time fuse is indicated at F between the first two contacts, and is fused after carrying the starting current a predetermined length of time.

It will be noted that I have indicated a motor M in the drawings having a shunt field winding, and that the supply circuit 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 themselves, giving a closed circuit for the field discharge. It will also be noted that I have provided in the forms of my invention shown in the accompanying drawings two no-voltage devices, one controlled by the coil H of the circuit breaker, and the other which retains the resistance controlling element in its final position. In the case of the no-voltage device comprising coil H, when no-voltage occurs under running conditions, the coil H would be deenergized comparatively quickly and the circuit would be quickly opened by the left hand arm G of the circuit breaker. But the resistance c011- trolling element would not be released by its retaining magnet until the counter electromotive force of the motor in the closed local loop, had decreased to a very low amount which would be several seconds in usual practice. In the meantime the operator would observe by the opening of G that no voltage had occurred, and he could usually close this switch before the motor VOIIJS 1121.6 (II'OPPGU. sulllclell ly b0 I'GIBZLSGJJIIB rheostat arm. If the line voltage had been restored in the mean time, the motor'could continue running and so avoid interruption of service. It is thus of advantage to have the two no-voltage devices, one acting comparatively quickly on the circuit breaker and unaffected by the motor volts, and the other having a delayed action and dependent upon a determinate reduction of the motor volts. Also the two separately acting novoltage devices, each acting upon its own movabe element, and these movable elements being in series with each other and with the motor armature, give a higher degree or reliability of protection. The em ployment of two no-voltage devices is not, however, essential to all forms of my invention, and my invention has many advantages other than those described.

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, I declare that what I claim as new and desire to secure by Letters Patent, is,

l. The combination of a motor rheostat having a movable element for varying the resistance, an outside main switch, an overload electro-responsive winding for controlling the opening of said switch, a novoltage elcctro-responsive winding for controlling the opening of said switch, and a contact controlled by movement of said element for controlling the magnetization and demagnetization of said no-voltage winding.

2. The combination with a motor rheostat, of a circuit breaker, a no-voltage coil for controlling said circuit breaker when closed, a control coil for the circuit breaker, and a circuit contact closed by the movement of the resistance controlling element for controlling said control coil.

3. The combination with a motor rheostat, of a circuit breaker, a no-voltage coil for controlling said circuit breaker when closed, a control coil for said circuit breaker, and a circuit contact adjacent to the first resistance contact of said rheostat and engaged by the resistance controlling element for controlling said control coil.

4. The combination of a motor controlling rheostat, a switch in the main circuit, means for protecting the circuit from overload, a 110-voltage device for opening said switch, and a controlling means having a contact at or near the off-position of the resistance controlling element of said rheostat.

5. The combination of a rheostat having a movable element for controlling the resist ance, a circuit breaker in circuit with said rheostat, an overload coil for effecting the opening of said circuit breaker, a no-voltage coil for controlling the opening of said circuit breaker, and a switch contact controlled by the movement of said element for affecting the movement of said circuit breaker.

(5. The combination of a resistance, a movable element for controlling said resistance, a switch in circuit therewith, an electromagnetic winding for controlling the movement of said switch, and a second electromagnetic winding controlled by the movement of said element for affecting the current in said first named winding.

7. The combination of a resistance, a movable element for controlling said resistance, a switch in circuit therewith, an electromagnetic winding for controlling the movement of said switch, and a second electromagnetic winding controlled by the movement of said element at its resistance all in position for affecting the current in said first named winding.

8. The combination of a resistance, a movable element for controlling said resistance, a switch in circuit therewith, an electromagnetic winding for controlling the movement of said switch, a second electro-magnetic winding controlled by the movement of said element for affecting the current in said first named winding, and an overload electro-magnetic device for automatically openiru said switch.

The combination with a motor rheostat, of a circuit breaker, a no-voltage coil for controlling said circuit breaker when closed, a control coil for the circuit breaker, and a circuit contact controlled by the movement of the resistance controlling element for controlling said control coil.

10. The combination of a motor controlling rheostat, a switch in the main circuit, a no-voltage device for opening said switch, means for protecting the circuit from overload, and a controlling means having a contact at or near the initial position of the resistance controlling element of said rheostat.

11. The combination of an electric motor, an armature resistance having a movable element, an electroresponsive controlling device, means for including said device in series with said resistance in the armature circuit of the motor by the movement of said movable element from running position, and )rotective means automatically controlled by said device.

12. The combination of an electric motor, an automatic circuit breaker automatically responsive both to no voltage and overload current, a circuit controlling element, means for normally restraining and automatically releasing said element, and electrical means for controlling the circuit breaker controlled by the movement of said element.

13. The combination of an electric motor, an automatic circuit breaker comprising two independently closable switches for automatically opening the motor armature circuit at two places upon overload current, a no voltage 0011 for controlling the automatic 0 enmg of at least one of said swltches upon the occurrence of no voltage, a spring actuated motor starting rheostat, and means for functionally relating said rh eostat and circuit breaker.

14. The combination of an electric motor, an automatic breaker in series with the motor armature comprising two controlling coils, each of said coils controlling said circuit breaker independently of the other and one being responsive to overload current through the motor armature and the other to no voltage, an armature controlling rheostat, and electrical means functionally relating said rheostat to said circuit breaker.

15. The combination of an electric motor, a movable circuit controlling element for controlling the armature circuit of said motor, said element being manually movable in both directions, a magnetic circuit breaker for protecting the motor armature from overload, and electrical means protectively relating the said element and circuit breaker, said means comprising a normally energized magnetic winding for controlling the circuit breaker under certain conditions.

16. The combination of an electric motor, a resistance having a movable element for controlling the armature circuit, an automatic st itch in series with the motor armature, an electroresponsive device for controlling said s11 itch, said device being normally energized, and means dependent upon the movement of said element for deenergizing said device and thereby controlling said itch.

17. The combination of an electric motor, two independently movable switches for producing tn 0 breaks in the motor armature circuit, said switches being in series with each other, a magnetic coil in series it ith the motor armature circuit for automatically opening said SfiitCl'lSS in response to overload current to the motor armature, a coil normally energized independently of the cur rent in the motor field or armature for controlling the automatic movement of at least one of said s1. itches, a third motor controlling sv. itch protectively related to one of said stitches, and means for causing the automatic protective movement of said third s':-. itch.

18. In a hand operated controller for a motor, the combination of four circuit controlling movable elements each of which may be moved manually independently of the others, three of said elements being in series tith each other and with the motor armature across a constant electromotive force circuit and the fourth being in a circuit in parallel "with the motor armature, and means for automatically and protectively moving three of said elements upon the oo- 19. The combination of an electric motor, an automatic magnetlc overload circuit breaker the switch of which carries the entire motor current, a second switch, no voltage responsive means energized by a current independent of the said motor current for causing the automatic opening of the motor armature circuit by said second switch upon the occurrence of no voltage, an independently movable motor controlling element functionally related to said second switch, and means for causing said element to be automatically and protectively moved under certain conditions.

20. The combination of an electric motor having a permanently closed local loop containing the motor armature, armature resistance and shunt field winding, and two automatically responsive protective switches for connecting and disconnecting said loop to and from the supply mains, one of said switches being automatically controlled by two responsive windings, one of said windings being in series with the motor armature and the other not in series with the motor armature relative to the supply mains, each of said two windings being responsive independently of the response of the other windings.

21. The combination of a resistance, a movable element for varying said resistance, a winding connected in series with said element and v. ith saidresistance by the move ment of said element from running position to a certain position, and automatic means for controlling the circuit controlled by said winding.

22. The combination of an electric motor, an armature resistance having a movable element, and automatic protective means comprising a winding for controlling said means, and means for including said winding in series with said resistance and the armature of said motor only by the movement of the movable element of said resistance to its initial position.

23. The combination of an electric motor, a starting resistance, protective means comprising an electroresponsive device, and means for connecting said device in series with some part of the starting resistance by the movement of the movable element of said resistance from running position to in.- clude a part of said resistance in the motor circuit.

24. The combination of an electric motor, a starting resistance, a protective switch, means for automatically controlling said switch comprising two electroresponsive windings, and means for connecting both of said windings in series with said resistance and the motor armature.

25. The combination of an electric motor,

' omprising DWO g electroresponsive windings, means for connecting one of said windings in series with said resistance and the motor armature and for causing said winding to be effective only when said resistance is in circuit, and means for connecting the other of said windings in series with said resistance and motor armature.

26. The combination with a supply circuit and a translating device, of an automatic protecivte circuit controlling element, said controlling element being automatically res onsive to change of current in two contro ling windings, and a third controlling winding for controlling the current in one of said two windings.

27. The combination of a supply circuit of constant electromotive force, and a branch circuit across said supply circuit, said branch circuit including in series the armature of an electric motor, a resistance for the motor, a movable resistance controlling element, an electroresponsive protective winding for said resistance, and the controlling winding and switch of an automatic overload circuit breaker.

28. The combination of a circuit controlling movable element normally acted upon by a force tending to move it, means comprising an electromagnetic winding for normally restraining said element,a second electromagnetic winding automatically placed in series with said element when said element is released and moved under the action of said force whereby said latter winding is adapted to be energized by a current thereafter passed through said element, and protective means controlled by said latter winding.

29. The combination of an automatic circuit breaker comprising two independently closable switches in series with each other and with a motor armature, each of said switches adapted to automatically open the circuit independently of the other upon overload current, and means for automatically opening at least one of said switches, said means comprising a magnetic winding normally out of circuit and which is automatically introduced in circuit in series with said switches under certain circuit conditions.

30. The combination of an electric motor, a starting resistance, and means for protecting said resistance against undue heating when current is established through the starting resistance comprising an electro magnetic winding in series with the motor armature, and connections for rendering said winding effective only when a current is passed through said starting resistance.

31. The combination of an electric motor, an automatic circuit breaker automatically responsive to two different abnormal current conditions, a starting rheostat for the motor,

electrical means for protectively relating said rheostat and circuit breaker, and electrical means for automatically controlling the movement of said starting rheostat.

32. The combination 01' an electric motor, an automatic circuit breaker automatically responsive both to no voltage and overload current, a circuit controlling element, means for normally restraining and automatically releasing said element, and a winding for controlling the circuit breaker controlled by the movement of said element.

33. The combination ol an electric motor, a controlling resistance, an electromagnetic winding, connections for placing said winding in series with the resistance when the movable element of the resistance is moved from a running position to insert resistance, and a circuit controlling element whose movement is automatically responsive to magnetization of said winding.

34. The combination of an electric motor having a shunt field winding connected to a circuit of constant electromotive 'l'orce,three independently movable protectively related circuit controlling elements, means forcontrolling the automatic movement of said three elements comprising a magnetic winding in series with the motor armature responsive to overload for controlling the automatic movement of said three elements, and means responsive to no voltage for controlling the automatic movement of at least two of said elements.

35. The combination of a motor having a shunt field winding connected to a constant electromotive l'orce circuit, and controlling means for said motor comprising two independently movable automatic circuit controlling elements in series with each other and with the motor armature, a magnetic coil also in series with the armature circuit for controlling the automatic protective movement of said elements when overload current is passed through the motor armature, a magnetic coil connected across the constant electromotive force circuit for causing the automatic movement of at least one of said elements when said latter coil is deenergized, a third automatically movable element lunctionally related to at least one of said two elements, and means for controlling the automatic movement 01' said latter element under certain conditions.

36. The combination of a supply circuit of constant electromotive force, an electric motor having a shunt field winding, an armature resistance, the motor armature, field winding and said resistance being connected in a permanently closed loop, two independently movable switch elements in series with each other and with said loop across said cir cuit, restraining means for at least one of said elements, overload responsive means controlling the automatic opening of both of said switch elements, said overload responsive means having a magnetically moved mass adapted to be moved and deliver a low to release said restraining means, and no voltage responsive means controlling the automatic opening of at least one ol' said switch elements, said latter means comprising a magnetic winding connected in parallel with said loop.

37. The combination of two functionally related motor controlling movable elements, at least one being a resistance varying element, means responsive to no voltage 'l'or automatically and protectively moving both ol said movable elements, said means comprising an electroresponsive device actuated by a current independent of the motor current, and an independently movable overload magnetic circuit breaker comprising an overload coil and a mass magnetically moved thereby for delivering a blow to release the switch of the circuit breaker.

38. The combination of a shunt wound motor, a constant electromotive lorce supply circuit, three inde endently manually movable circuit control ing elements, means responsive to no voltage for automatically controlling the movement of at least two of said elements, and means res onsive to overload current for automatically controlling the movement of at least one of said elements.

39. The combination of a motor having a field winding energized independently of the armature current, a movable circuit controlling protective element, means comprising a magnetic winding responsive to no voltage and normally energized independently of the current in the motor armature or field winding for controlling the protective movement of said element upon the occurrence of no voltage, a movable resistance controlling element manually and independently movable, means for causing said latter element to automatically move to a protective position upon the occurrence of no voltage, and an independently movable overload magnetic circuit breaker.

40. The combination of a constant electromotive lorce supply circuit, an electric motor having a shunt field winding, two independently movable automatic switches connected in series with each other and with said motor, an armature resistance having a movable element for varying said resistance, means comprising an overload coil for controlling the automatic movement of both of said switches, means comprising a no voltage winding for controlling the automatic movement 01' at least one 01' said switches, two pivotally connected switch elements connected in series with said no voltage winding across said supply circuit, a spring tending to force said switch elements toward each other, a latch for holding one of lllllg POSLtlUrl, Zulu 1115mm LUl latch comprising an electroresponsive winding energized by movement of said resistance varying element to its initial position whereby the said movement of the resistance varying element to its initial position will cause the said no voltage winding to be deenergized.

41. The combination with an electric motor, of controlling means comprising a movable member, a second movable memher, a resistance controlled by the latter member, and electrical contact means rendering the former member ineffective while the latter member occupies predetermined positions.

42. The combination with an electric motor, of controlling means comprising a movable member, a second movable member, a resistance controlled by the latter member, electrical contact means rendering the former member ineffective while the latter member occupies predetermined ositions, and a protectively functionally re ated circuit breaker.

43. The combination with an electric motor, of controlling means comprising a movable member, a second movable member, a resistance controlled by the latter member, electrical contact means rendering the former member ineffective while the latter member occupies predetermined positions, and an overload circuit breaker comprising two independently closable automatically openable switches in series with each other and with said resistance controlling member.

44. The combination of an electric motor, a movable element for controlling the circuit of said motor, automatic protective means comprising a winding, and means whereby the movement of said element from a running position connects said winding in series with the motor circuit and thereby causes said protective means to be effective.

45. The combination of an electric motor, a movable element for controlling the motor, motor controlling means, and means whereby electrical contacts are made and broken by the movement of said element for rendering ineffective and effective the said motor controlling means.

46. The combination of an electric motor, a rheostat having a movable element for controlling resistance in series with the armature of the motor, a no voltage protective switch, and means for controlling the no voltage device of said switch when the movable element of said rheostat is moved to a certain position and thereby cause the protective movement of said switch.

47. The combination of an electric motor, a protective switch automatically responsive to no voltage, restraining and releasing means therefor comprising a latch and an vnvwnm s W mg.

48. The combination of an electric motor, an armature rheostat and a no voltage switch in series with each other and with the armature of said motor, said no voltage switch comprising a magnetic winding, and means whereby the circuit of said winding is controlled by said rheostat for causing the protective movement of said switch.

49. The combination of ano voltage switch comprising a restraining latch, an actuating spring, and a magnetic coil for releasing the latch, a rheostat in series with said switch, and means whereby the circuit of said coil is controlled by the movement of said rheostat.

50. The combination of an electric motor, an armature rheostat, ano voltage switch, said rheostat and switch and the motor armature being in series with each other, and the said rheostat and switch being mounted independently of each other, the said switch being controlled in its protective movement by a coil acting independently of the motor current, and means whereby said coil is controlled by the movement of the movable element of said rheostat.

51. The combination of an electric motor, an automatic circuit breaker responsive to overload and no voltage and comprising two independently closable switches in series with each other and with the motor armature, an armature resistance also in series with said switches, said armature resistance having no open circuit position, and a manual switch adapted to deenergize the no voltage winding of said circuit breaker and thereby open the circuit at the circuit breaker.

52. The combination of an electric motor, an armature rheostat comprising stationary and movable contact elements and having no open circuit position, means for short circuiting said contact elements of said rheostat when the movable element is moved to final position, a separate automatic circuit breaker responsive to no voltage and overload, and a manual switch adapted to deenergize the no voltage winding of the circuit breaker and thereby cause the opening of the circuit breaker at the will of the operator.

53. The combination of an electric motor, a double pole circuit breaker comprising two independently closable switches in series with each other and with the motor armature, an armature rheostat also in series in the armature circuit and adapted to vary the resistance without opening the armature circuit, the said circuit breaker having a coil also in series in the armature circuit and controlling the automatic opening of the circuit breaker upon overload and also having a coil energized independently of the motor armature and field winding for controlling the automatic opening of the armature circuit at the circuit breaker upon no voltage, and a manual switch for deenergizing the said no voltage coil and thereby cause the opening of the circuit at the circuit breaker.

54. A motor controlling apparatus, comprising an armature rheostat, an automatic circuit breaker responsive to no voltage and to overload, a switch adapted to be manually opened and closed, the said switch being connected so as to cause when operated the actuation of the no voltage device of the circuit breaker and thereby cause the opening of the circuit breaker at the will of the operator, and means protectively relating the rheostat and circuit breaker for insuring their proper operation.

55. The combination of a constant electromotive force supply circuit, an electric motor, two automatic independently closable switches both of which are automatically responsive to overload current, a controlling rheostat, the said switches, rheostat and motor armature being connected in series with each other across said supply circuit, means comprising a winding responsive to no voltage and adapted when deenergized to cause the opening of at least one of said switches, and a manual switch controlling the operation of said no voltage responsive winding whereby the circuit can be opened at one of said first named switches at the will of the operator.

56. The combination of a constant electromotive force supply circuit, an electric motor, two automatic independently closable switches both of which are automatically responsive to overload current, a controlling rheostat, the said switches, rheostat and motor armature being connected in series with each other across said supply circuit, means comprising a winding responsive to no voltage and adapted when deenergized to cause the opening of at least one of said switches, and an automatic switch controlling the operation of said no voltage responsive winding whereby the circuit can be opened at one of said first named switches.

57. A motor controlling apparatus comprising a rheostat having a movable element, two independently movable switches, means whereby one of said switches is automatically responsive to no voltage, and means whereby the other of said switches is caused to be operated by the movement of said movable element to a certain position.

58. A motor controlling apparatus comprising a rheostat having a movable element, two independently movable switches, means whereby one of said switches is automatically responsive to no voltage, means whereby the other of said switches is caused to be operated by the movement of said movable element to a certain position, and means for functionally relating the operation of said two switches.

59. The combination of an automatic switch responsive to no ltage, a rheostat having a movable element, means for controlling the opening movement of said switch by the movement of said element to a certain position, and means for automatically controlling the movement of said element by said no voltage switch.

60. A motor controlling apparatus comprising three automatic functionally related manually movable elements, one of said ele-' ments being a switch responsive to no voltage, and means wnereby another of said elements controls the opening movement of said no voltage switch when manually moved to a certain position.

61. The combination of an electric motor, an armature controlling rheostat having a movable element, an automatic switch responsive to no voltage connected in series with said rheostat and the motor armature, means for causing the automatic opening of said switch when the movable element of the rheostat is moved to a certain position, and manual electrical means whereby the opening of said switch may be caused at the will of the operator.

62. The combination of an electric motor, an automatic switch responsive to no voltage, a rheostat having a movable element in series with said switch and motor armature, means for controlling the automatic opening of said switch when said element is manually moved to a certain position, and means whereby the movement of said element is automatically controlled upon the automatic movement of said switch.

63. The combination of a switch, a pivoted latch for holding said switch in closed posi tion, means whereby said switch is automatically responsive to no voltage, a rheostat having a movable element, and electrical means controlled by said switch for causing the automatic movement of said element.

64. The combination of a switch, a latch for holding said switch in closed position, means whereby said. switch is automatically responsive to no voltage, a rheostat havin a movable element, electrical means control ed by said switch for causing the automatic movement of said element, and electrical means for controlling the automatic movement of said switch when said element is moved to a certain position.

65. The combination of a constant electromotive force supply circuit, an electric motor, three automatic switches in series v. ith each other and with the motor armature across said supply circuit, each of said switches being automaticall openable independently of the others, at least one of said switches being controlled in its automatic movement by a no voltage winding independent of the armature and field current of the motor and at least two of said switches being controlled in their automatic movement by a winding in series with the motor armature.

66. The combination of an electromotive force producing winding, two circuit controlling movable elements in series with each other and with said winding, means for causing each of said elements to be automatically responsive to no voltage, and means whereby the manual movement of one of said elements electricall controls the automatic movement of t e other.

67. The combination of a circuit controlling element, a rheostat having a movable element in series therewith, means for causing said first named element to be automatically responsive to no voltage, and electrical means for causing the automatic movement of said first named element when the rheostatic element is moved to a certain position.

68. The combination of an electric motor, an automatic switch, a rheostat having a manually movable element in series with said switch and the motor armature, said element being manually movable in both directions, said switch comprising a winding responsive to no voltage, and means whereby said winding is controlled by the movement of said element.

69. The combination of an electric motor, an automatic switch, an automatic rheostat having a movable element in series with said switch and the motor armature, said switch and said rheostat each comprising a winding responsive to no voltage, and means for rendering the no voltage winding of said switch ineffective by the movement of themovable element of the rheostat to a certain position.

70. In a controlling apparatus, a circuit controlling element, a pivoted latch for holding said e ement in closed position, a no voltage windin for controlling the opening movement 0% said element, a second circuit controlling element in series with the other element, and no voltage responsive means for controlling said second element.

71. The combination of a constant electromotive force supply circuit, an electric motor, an automatic switch, an armature rheostat having a movable element, a winding responsive. to overload current, said switch, rheostat and winding being connected in series with the motor armature across said supply circuit, said automatic switch comprising a winding responsive to no voltage, and means whereby said no voltage winding is denergized upon the occurrence of overload current through said overload winding and also denergized when said movable element is moved to a certain position.

72. The combination of an electric motor, an automatic switch, a rheostat having a manually movable element in series with said switch and the motor armature, said element being manually movable in both directions, said switch comprising a winding responsive to no voltage, and electric means dependent upon the movement of said element to a predetermined position for controlling a current and thereby controlling the automatic movement of said switch.

7 3. The combination of an electrically controlled, automatically movable switch, said switch being automatically responsive to no voltage, a rheostat having a movable element in series therewith, said element bein manually movable in both directions, and electric contact means dependent upon the movement of said movable element to a certain position for electrically controlling the automatic movement of said switch.

In testimony whereof, I affix my signature in the presence of two witnesses.

H. WARD LEONARD. lVitnesses L. K. SAGER, GEO. A. HOFFMAN.

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