US955137A - Controller for electric motors. - Google Patents

Description

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CONTROLLER FOR ELECTRIC MOTORS.

'APPLIOATIOR FILED un. 26, 1909.

Patented Apr. 19,1910.

2 SHEETS-SHEET 1.

UNITED STATES PATENT OFFICE.

WILLIAM H. CONNELLY, OF CHICAGO, ILLINOIS, ASSIGNOR TO THE ELECTRIC CON- TROLLER AND MANUFACTURING COMPANY, OF CLEVELAND, OHIO, A CORPORATION OF OHIO.

CONTROLLER FOR ELECTRIC MOTORS.

Specification of Letters Patent.

Patented Apr. 19, 1910.

Application filed January 26, 1909. Serial No. 474,214.

To all whom 'it may concern:

Be it known that I, WILLIAM M. CON- NELLY, a citizen of the United States, residing-at Chicago, in the county of Cook and State of Illinois, have invented or discovered new and useful Improvements in Controllers for Electric Motors, of which the following is a specification.

My invention relates to hand controllers for electric motors and has for its object the rovision of means for causing arcs to be ormed at the contacts of magnetically-controlled switches rather than at those on the hand controller, by which the said switches are governed.

Referring to the accompanying drawings, Figure 1 is a diagrammatic showing of a motor control system embodying the princi les of my invention; Fig. 2, a perspective 0 .the central portion of a pair of connected controller arms which I prefer for actual use; and Figs. 3 4, and 5, front, side, and rear elevations of a hand controller provided with my improvements.

Referring first to Fig. 1, S is a main knife switch and S, S S and S are magnetically operated switches.

A is the armature of the motor to be controlled, and F, its field.

C is a diagrammatic view of the hand controller. The arm C" of the hand controller C is arranged to be moved by the arm C through the connecting rod C The slot C is provided in the connecting rod which allows a certain movement of the arm C before movement of the arm C takes place. If the arm C is moved in the forward direction, it will reach the position p before any movement of the arm C takes place, and by the time the arm C has reached position the arm C will have reached the position P, which is the first running point of the controller. As the arm C is advanced to the successive positions p and 72*", the arm 0 advances toward t e position P In coming to the off-position, the arm G moves through the whole distance allowed by the slot 0* before the arm C starts to move, and the arm C will leave the fixed contact p before the arm 0 can leave the fixed contact P. This causes the ma ets of all the magnetically-operated swltches to be denergized and provides a short interval of time between the opening of these switches and the opening of the connections between the arm C and the contact P. This time interval allows the magnetically-operated switches to open and break the motor circuit. If the arm C and the arm C should leave their fixed contacts at the same time, the short time required for the magnetic switch to open would throw the are on the contacts of the hand controller, especially if the hand controller arm is moved quickly to the ofi position. The delayed motion of the arm C, which is accomplished by my invention, forces the magnetically-operated switches always to break the motor circuit, thus preventing any arcing on the hand controller cont-acts.

On moving the controller arm G to osition p the arm C will be in the position P and the following circuits will be established: from the positive side of the switch S through the wire 12, the operatin solenoid of the switch S, the wire 10, the contacts 0 and 0 the brush b the contact a and the wires 11 and 6 to the negative side of the switch S. This closes the magnetic switch S and establishes a motor circuit as follows: from the positive side of the switch S through the switch S, the starting resistance R, the wire 2, the series field F, the wire 3, the contact 0 the brush 1), the contact 0 the wire 4, the armature A, the wire 5, the contact 0 the brush b the contact 0 and the wire 6 to the negative side of the switch S. This circuit starts the motor in the forward direction with all of the starting resistance in circuit. If the controller arm C is moved to position f, a control circuit is established through the wire 12, the wire 13, the auxiliary contacts of the switch S, the operating solenoid of the switch S the wire 9, the contact 0 the brush 1), the contacts a and c and the wires 11 and 6 to the negative side of the switch S. This closes the secondaccelerating switch S which short circuits part 1" of the starting resistance R, tending to accelerate the motor A. On further movement of the controller handle to positions p and 12 similar circuits are established, closing switches S and S, cutting out the remainder of the starting resistance sections 1' and r and placing the motor directly across the line. If now the controller handle is brought quickly to the off-position, the control circuits of the switches S, S

Pa fre -r.

S, and S will be broken before the brushes Zr and b of arm C5, leaving their contacts 0, c, and 0 0 respectively. If new the controller arm C is moved in the reverse direction, until the arm reaches the position the arm C will have reached the position 32 The switch S now closes by a circuit through its operating coil, the wire 10, the contact 0 the brush 6*, the contact 0*, and the wires 11 and 6 to the negative side of the switch S. This closes the motor circuit from the positive side of the switch S, through the switch S, the startin resistance R, the wire 2, the series field F? the wire 3, the contact 0 and c", the brush 6, the contact 0", the wire 5, the armature A in the reverse direction to that before, the wire 4, the contact 0 the brush 6, the contact 0 and 0 and the wire 6 to the negative side of the switch S. This reverses the direction of the armature A. The switches S S and S are closed as before by advancing the arm C to the positions p, p, and p respectively Bringing the operating handle H again to the off osition to stop the motor, the arm C eaves its fixed contacts before the arm C leaves its fixed contacts, thus again bringing the rupture of the motor circuit on the magnetically-operated switches and preventing the breaking of the motor circuit on the contacts or contact brushes of the arm C.

Although I have shown this device as used with a simple magnetic switch controller with hand reverses, it is possible to use it with a magnetic switch controller employing any system of automatic acceleration, or in connection with any special features used in connection with this class of controllers. The motor may be either series, shunt, or compound wound.

7 My invention may be used with alternating current motors as well as direct current motors.

Although I have shown certain means of obtaining the delayed motion of the contact arm C carrying the motor circuit, it is to be understood that this action may be obtained by any number of mechanical devices without departing in any way from the spirit of the invention.

to be controlled Referring now to Figs. 2, 3, 4, and 5, I show the manner in which I prefer to embody my invention. 14 represents a drumlike casing having on one end the fixed contacts c to 0 and on the other end the fixed contacts 0 to 0 The arm C which cooperates with the contacts 0 to 0 and the arm C which cooperates with the contacts 0 to 0 are carried on the ends of the shaft 15 which occupies a central or axial position in the casing. The arm C is secured rigidly to the shaft 15 by the pin 16, but the arm C is loosely mounted thereon. The arm C has a pair of lugs or shoulders 17, having between them at diametrically opposite positions the depressions or spaces 18 into which the pin 19, extending through the shaft 15, projects. WVhen the arm C is moved the arm C will lag behind, no matter in what direction the former is moved. It is clear that the arms connected as shown in Figs. 5 will produce the same results as those described in connection with the diagrammatic showing on Fig. 1.

I claim 1. An electric circuit, a magnetically-operated switch having contacts in the said circuit, a second switch also having contacts in the said circuit, a third switch having contacts for governing the magnet of the first switch, and a lost motion connection between the second and third switches, by means of which the third switch may operate to open the circuit of the winding of the first switch before the contacts of the second switch are separated.

2. An electric circuit, a magnetically controlled switch having contacts in the said circuit, a controller casing having thereon contacts in the said circuit and in the circuit of the winding of the said switch, arms having brushes for closing the said contacts, a shaft connecting the said arms, and means for causing the shaft to rotate idly for a limited distance and then to cause the rotation of the arm having contacts in the first named circuit.

Signed at Chicago, Illinois, this 23 day of January 1909.

WM. M. CON NELLY. Witnesses:

HARRY W. EASTWOOD, C. S. WATKINS.

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