US790100A - Safety device for motor-starters. - Google Patents

Description

No. 790100. Y PATENTED MAY 16, 1005.-

F. G. BILL.

SAFETY DEVICE FOR MOTOR STARTERS.

' APPLICATION FILED FEB. 21, 1905.

0 o Q Q w Q Q WITNESSES INVENTOI? fififwz fiederz'c%&'. Bz'ZZ A TTOIMEYS UNITED STATES Patented may 16, 1905.

PATENT OFFICE.

FREDERICK G. BILL, OF LONG ISLAND CITY, NEW YORK, ASSIGNOR OF ONE-HALF TO FRANCIS H. MURPHY, OF NEW YORK, N. Y.

SAFETY DEVICE FOR MOTOR-STARTERS.

SPECIFICATION forming part of Letters Patent No. 790,100, dated May 16, 1905.

Application filed February 21, 1905. Serial No. 246,663.

To (r/ZZ whom it may concern:

Be it known that I, FREDERICK Gr. BILL, a citizen of the United States, residing at Long Island City, in the county of Queens and State of New York, have invented certain new and useful Improvements in Safety Devices for Motor-Starters, of which the following is a specification, such as will enable those skilled in the art to which it appertains to make and use the same.

The object of this invention is to provide a device for use in connection with starting devices for electric motors and by means of which the burning out of fuses, rheostats, or armatures is obviated in the event of the rheostat-arm being engaged in any manner in its outward position, as frequently occurs, a further object being to provide a supplemental electrical circuit adapted to operate electrical circuitclosers when the rheostatarm is in its normal position, and thereby close the main circuit in which the'motor is arranged, said supplemental circuit being open when the rheostat-arm is out of its normal position and being closed only when said rheostat-arm is in its normal position.

It will be understood that rheostats are generally employed in an electrical motor-circuit, said rheostat gradually increasing the amount of current through the motor as the arm thereof approaches its outward position,

and it frequently happens that the rheostatarm sticks in its outward position and is overlooked by the operator, and if the main switch of the motor-circuit be opened the motor stops; but if the switch be again closed the motor receives the full force of the electric current directly when the rheostat-arm is in its outward position, and the burning out of fuses or armatures frequently results; and my invention is intended to obviate this possibility, as will be readily understood from the following description, when taken in connection with the accompanying drawing, said drawing representing a diagrammatic view of the main circuit and of the supplemental circuit as well as the mechanical parts which I employ.

In the drawing I have indicated a feed electrical conductor a and a return electrical conductor 6, said conductor being connected with an electrical generator in the usual or any desired manner, said generator not being indicated in the drawing, and the conductor.

a is provided with a contact and the conductor 7) with a contact 5 with each of which a double switch 0 is adapted to operate, said switch beingcon'iposed of two members 0 and c, the member 0 thereof being adapted to operate in connection with the contact a and the member 0 with the contact and connected with the member 0 is an electrical conductor (Z, connected with one side of a motor and also in connection with the member 0 is an electrical conductor 1 which is connected at its other end with an electromagnet 0.

Connected with the member 0 of theswitch c is a conductor f, which is connected at its other end with a contact f and with a conductorf", in electrical connection with one of the members 9 of a plug-box g, the other member thereof being connected with the electromagnet c by means of an electrical conductor f, and also in electrical connection with the member 9 of the plugbox 1 is a conductor la, the other end of which is connected with the member a of a plug-box similar to the plug-box g, and the member 75 of the plug-box lzf is connected with the member g of the plug-box by means of a conductor if.

Pivotally connected with the core 0 of the eleetromagnet c is a lever 1 provided with a contact r, adapted to operate in connection with the contact 7, and the lever is also provided with a plug 1', which is adapted to pass between the spring members and of the plug-box thereby placing the same in electrical communication, and in electrical communication with the lever v' is a conductor of, the other end of which is in electrical connection with a rheostat-arm Z" of a rheostat i and connecting the outer contact of v the r h eostat Zr with a motor d 2 is a co n d ucto r in.

The rheostat-arm 7': is provided with a projecting member A, which is adapted to bear against one of two vertical members m or m of a slide m mounted in a suitable guide m and connected with the guide m is a spring or other friction device 172, which bears against the bottom of the slide m, andthe outer end of the slide m is provided with a plug m, which is insulated therefrom and is adapted to enter the plug-box [L3 and place the members if and h thereof in electrical communication.

In the drawing forming part of this specification the parts of my apparatus are shown in an open position, and if at this time the switch 0 be moved to the contacts a and b the current passes through the wire a, member c of the switch ,0, wires f, f, and h to the member If of the plug-box 72,3, and if the rheostat-arm be in the position shown in the drawing the current passes through the plug 7L6, member [L2 of the plug-box it", wires in and f, through the electromagnet e and wire 6 to the member 0 of the switch 0', and thence through the wire I) to the generator, and the circuit is complete. When the electromagnet e is energized in the manner just described, the lever c' is drawn outwardly until the contacts z' and f touch each other, at which time the plug i enters the plug-box 9, thereby placing the members thereof in electrical communication with each other, and the current then passes through the wire a, member 0 of the switch 0, wire f, lever c, wire 0", rheostat 14*, wire 70 to the motor W, and thence through the wire 03, member 0 of the switch 0, and wire I) to the generator, and the motor 9 is energized through the resistance of the rheostat I0 and as the arm k of the rheostat [r is moved toward its outward position the resistance is cut out and the motor (Z gains momentum and power until the extreme outer position of the arm 70 has been reached, at which time the resistance is entirely cut out; but in this movement of the arm k the member if thereof has forced the slide m backwardly, thereby releasing the plug m from the plug-box b and the members k and h of the plug-box k are no longer in electrical communication, and when it is desired to stop the motor d the switch 0 is operated to break the circuit in the usual manner. When the current is thus shut off from the main or motor circuit, the arm Z0 is in its extreme outward position, and, as previously stated, it frequently happens that the arm it sticks in this position. If there are mechanical means for returning it to its normal position or if manual means are employed for returning the arm In to its normal position, the return thereof is liable to be overlooked by the operator, and if the switch were to be closed with the arm 7c in this position the motor (i would receive the full force of the current at once if the main circuit were complete; but when the slide m is moved backwardly and the members 71. and [L4 of the plug-box k are out of electrical communication the supplemental circuit is broken through theplug-box b and a supplemental circuit is completed through the conductor a, member 0 of the switch 0, wires f and f plug-box g and plug 1*, wire f, electromagnet 0 wire 6, the member c of the switch 0, and wire I) to the generator, thus serving to hold the lever 71 in its innermost position, and when the switch 0 is open the electromagnet e is denergized and the lever i rises, thereby separating the contacts i and f and the main or motor circuit is thereby broken, and if the switch 0 be closed at this time and the arm 70 of the rheostat k be in its outer. position or adjacent thereto the supplemental circuit is incomplete because of the removal of the plug on from the plugboX if, and neither the electromagnet 6 nor the motor d are energized until the arm 70 is returned to its normal position manually, thereby forcing the plug m into the plug-box if, at which time the operation first described is repeated and the motor is energized and the power thereof gradually increased according to the movement of the arm 70. It will therefore be seen that I provide positive means for preventing the closing of a main or motor cirv cuit when the rheostat-arm thereof is out of its normal position and also provide means whereby the main or motor circuit is automatically closed when the rheostat-arm is in its normal position, and in this way a great saving of fuses and other portions of the electrical apparatus results, and it will also be understood that my invention may be adapted to electrical circuits of any kind or class wherein a rheostat is employed, and various changes in and modifications of the mechanical elements shown and described in this specification may be made without departing from the spirit of my invention or sacrificing its advantages.

Having fully described my invention, what I claim as new, and desire to secure by Letters Patent, is

1. In a motor-circuit, a circuit-closer, comprising a lever, an electromagnet in operative connection therewith, a rheostat, an arm therefor, and devices in operative connection with said arm for completing a circuit through said electromagnet when said arm is in its normal position, substantially as shown and described.

2. In a motor-circuit provided with a switch and rheostat, acircuit-closer, an electromagnet in operative connection therewith, a supplemental circuit through said switch and said electromagnet, and devices connected with a lever for closing said supplemental circuit, substantially as shown and described.

3. In amotor-circuit provided with the usual switch and rheostat, a circuit-closer comprising a lever, an electromagnet in operative connection therewith, a plug-box, a plug adapted to operate therewith, a supplemental electrical circuit through said switch, electromagnet and plug-box adapted to be completed and broken In testimony that I claim the foregoing as by said plug, and devices connected with said my invention I have signed my name, in pres- IO rheostat and said plug for completing said ence of the subscribing witnesses, this 20th supplemental circuit when the arm of said rheday of February, 1905.

ostat is in its normal position and for break- FREDERICK Gr. BILL.

ing said supplemental circuit when said rhe- Vitnesses:

ostat-arm is out of its normal position, sub- F. A. STEWART,

stantially as shown and described. C. J. KLEIN.

Images