US714351A - Induction-motor starting device. - Google Patents

Description

Patented Nov. 25, I902. A. H. ABELL. INDUCTION MOTOR STARTING DEVICE.

(Application filed Apr. 19, 1902.)

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(No Model.)

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No. 7l4,35l. Patented Nov. 25, I902.

- A. H. ABELL.

INDUCTION MOTOR STARTING DEVICE.

(Application filed Apr. 19, 1902.)

(No Model.) 2 Sheets-Shoe: 2.

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' UNITED STATES,

PATENT OFFICE.

ARTHUR H. ABELL, OF SOHENEOTADY, NEW YORK, ASSIGNYOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEIV YORK.

INDUCTION-MOTOR STARTING DEVICE.

.SPECIFIGATION forming part of Letters Patent No. '7 14,351, dated November 25, 1902.

A Application filed April 19, 1902.

T0 on whom it may concern.-

Be it known that I, ARTHUR H. ABELL, a citizen of the United States,residin g at Schenectady, county of Schenectady, State of New 'York, have invented certain new and useful Improvements in Induction-Motor Starting Devices,(Oase No. 2,473,) of which the following is a specification.

The present invention relates to starting devices for alternating-current motors, espe-- cially such induction-motors as use a resistance in the secondary circuit, which resistance is gradually cut out when starting the motor.

The main object of my invention is to so construct said device and so connect the mainline switch with the resistance-varying means as to render it practically impossible to close said main-line switch until the resistance has been inserted in the secondary circuit and also to prevent said resistance from being reinserted while the motor is running without first opening the main-line switch.

My invention consists of a switch for connecting the primary of the induction-motor or transformers connected with the same to the line and mechanism for operating the means for varying the resistance in the secondary winding of the motor to cut out said resistance after the main switch has been closed. The said mechanism comprises a shaft capable of rotation in one direction only, means for preventing a reverse rotation of said shaft, an operating-handle for said shaft, and arms or lugs carried by the shaft for operating the main switch and the resistance-varying means.

Instead of varying the resistance of the secondary circuit in starting the motor my device may be usedin connection with the means commonly employed for varying the fractional voltage impressed upon the primary of the motor.

My invention will be more readily understood if reference is had to the accompanying drawings, of which- Figure 1 is an elevation of the main-line switch and the mechanism for connecting the same to the resistance-varying means. Fig. 2 is a plan view of the same. Fig. 3 is a detail of said mechanism in a different position Serial No. 103.729. (N0 model.)

from that shown in Fig. 1. Fig. 4. is a plan view showing one way in which the present invention may be applied to a motor-generator set, and Fig. 5 is a diagrammatic representation of the electrical connections between the motor starting device and the motor when the starting resistance is inserted in the secondary circuit.

Referring now to Fig. l, A represents a switch in the main-line circuit. The switch here shown is a Well-known type of gravityopening oil-switch and forms no part of my present invention. The switch proper comprises the fixed contacts 5 and the movable contacts .9. (Shownin their normal open position in dotted lines in Fig. 1.)

0 represents a casing surrounding said "switch-contacts, and 10 represents the linewires leading from the same; Attached to the upper part of the casing c is the frame f, which carries the switch-operating mechanism. One arm n of the bell-crank lever m n, pivoted in the frame f at t, is attached to the movable switch contacts 3', while the other arm m is connected to one end of the link 6', the other end of the link e being pivoted to the arm n of the bell-crank lever m n, pivoted to the frame f at r. Therefore it will be seen that a movement of the arm 'm to the left will serve to close the switch A, in which position the switch is held by the dog (1, pivoted to the frame f at d, riding over and catching on the pin 6, carried by the arm m. The switch is opened by gravity when the bell-crank lever m n is released. Also supported by the frame f is the shaft 0, carrying the operating-handle h and the arm or lug b, on the outer end of which is mounted the roller 0, which coacts withthe arm or of the bell-crank lever m n. The shaft or also carries a finger h, which coacts with the dog 61 to trip the same when it is desired to open the switch A, and an arm f, on which is mounted the pin g, operating in the slot 7c of the link Z, which connects the operating mechanism with the resistance varying device through the levero and the rock-shaftp. The shaft 0, is adapted to be rotated in one direction only. As shown, it is in a clockwise direction and is prevented from rotating in a reverse direction by means of a ratchet-andpawl mechanism comprising the ratchetwheel r fixed upon the shaft a, and the pawl p, pivoted to the frame f.

The operation of the device will now be described. The shaft a is rotated in a righthanded or clockwise direction by means of the handle h, and as it rotates the roller 0, carried by the arm I), engages the arm m and closes the switch A, the dog (1 riding over the pin e to maintain said switch in its closed position. During this first movement of the shaft a the shaftp is not operated, the pin g, carried by the arm f, merely traversing the slot in the link I. A further movement of the shaft a causes the shaft 19 to rotate, thereby cutting out the starting resistance and speeding up the motor. When all the resistance has been cut out, the operating mechanism is in the position shown in Fig. 3, one hundred and eighty degrees from its original position. The resistance may be varied by any of the well-known means-such, for instance, as that shown and described in the patent to H. G. Reist, No. 678,034, granted July 9, 190l the shaft 9 of the herein-described device being connected to the shaft for operating the registance-varying switch of said patent by means of a rack-and-pinion or yoke mechanism, whereby when said shaft 19 is rotated the said resistance-switch-operating shaft will be moved in and out to vary the resistance. When it is desired to stop the motor, the shaft a must be moved forward in the same direction as before, the ratchet mechanism 19' 1' preventing any reverse movement of said shaft. During this forward movement the dog at is first tripped by the finger 1), thereby releasing the arm m and allowing the switch to open by gravity, and then the starting resistance is cut into the secondary circuit and the starting mechanism is returned to its original position, the shaft at having made one complete rotation.

In Fig. 4 I have shown my starting device as applied to a motor-generator, M representing an induction-motor, in the secondary of which the starting resistance is connected. A represents the main switch, and C a pedestal on which said switch is mounted. The resistance carried by said motor-armature may be varied by the means above described.

Fig. 5 shows diagrammatically the electrical connections between the main switch A, the motor M, and the resistances r,which are located in the secondary circuit of said motor. The link Z is connected to the lever 03, attached to the moving contact 1 of the resistance varying means. In the position shown all the resistance is in circuit in the secondary; but as the contact 3 is rotated to the right the resistances are gradually cut out, until in its final position the contact y forms a short circuit for said resistances. The resistances may be carried by the armature of the motor or may be mounted on a switchboard-panel at a distance from said motor-armature. In either case the operation of my present invention would be as above described.

Although I have shown and described my invention as applied to alternating-current motors, in which the starting resistance is placed in the secondary circuit, I do not intend to limit myself to such an application, as the invention is equally applicable to systems in which the starting resistance is included in the primary circuit, or to such systems as use a low-impressed electromotive force in the primary of the motor, increasing the same gradually up to the potential of the line as the motor increases in speed.

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

1. In combination with an alternating-current induction-motor, a switch for opening and closing the circuit between the motor and a suitable source of supply, a resistancecontrolling or other regulating device for controlling the fiow of current in the motor circuit at starting, and operating mechanism constructed and arranged to first close the switch, then to operate the regulating device, and thereafter to open the said switch by a continued movement of the operating mechanism in the same direction.

2. In combination with an alternating-current induction-motor, a switch for opening and closing the circuit between the motor and a suitable source of supply, a resistancecontrolling or other regulating device for controlling the flow of current in the motor-circuit at starting, and operating mechanism constructed and arranged to first close the switch, then to move the regulating device to increase the speed of the motor, and thereafter to open said switch and return the regulating device to its original position by a continued movement of the operating mechanism in the same direction.

3. In an induction-motor starting device, a switch in the primary circuit, a resistance in the secondary circuit, means operated by a single handle for closing said switch and cutting out-said resistance, and means operated by a further movement of said handle for opening said switch and cutting in said resistance, said switch being opened before the resistance is cut in.

4. In an induction-motor starting device, a switch in the primarycircuit, a resistance in the secondary :circuit, a shaft adapted to move continuously in one direction only, means for preventing the reverse movement of said shaft, and means carried by said shaft for closing said switch, cutting out said resistance, opening said switch and cutting in said resistance in the order named.

5. In an induction-motor starting device, a switch in the primary, ,a resistance in the secondary, means for varying said resistance, a shaft adapted to be rotated by an operatinghandle, means carried by said shaft for closing said switch, means independent of said shaft for maintaining said switch in its closed position, means carried by said shaft for causing said switch to open, and means also carried by said shaft for operating said resistance-varying means to cut out said resistance after said switch has been closed and to cut in said resistance after said switch has been opened.

6. In an induction-motor starting device, a switch in the primary, a resistance in the secondary, means for varying said resistance, a shaft adapted to be rotated in one direction only, means for preventing said shaft from being rotated in the opposite direction, means carried by said shaft for closing said switch, means independent of said shaft for maintaining said switch in its closed position, means carried by said shaft for opening said switch, and means operatively connected with said shaft for causing said resistance-varying means to operate to cut out said resistance after said switch has been closed and to cut in said resistance after said switch has been opened.

'7. In an induction-motor starting device, a switch for opening and closing the circuit between the motor and a suitable source of supply, a resistance-controlling or other regulating device for controlling the flow of current in the motor-circuit at starting, a shaft adapted to be rotated in one direction only, means for preventing a reverse movement of said shaft, an arm carried by said shaft adapted to coact with said switch to close the same, a dog for maintaining said switch in its closed position, a finger also carried by said shaft adapted to trip said dog to allow said switch to open, and means operatively connected with said shaft adapted to operate said regulating device.

8. In combination, a gravity-opening oilswitch, a rotatable shaft, an arm mounted on said shaft adapted to cooperate with said switch to close the same, a dog independent of said shaft for holding said switch closed, and a finger mounted on said shaft for tripping said dog to allow said switch to open.

9. In combination, a switch, a rotatable shaft, an arm mounted on said shaft adapted to coact with said switch to move it into a certain position, a dog adapted to maintain said switch in said position, and afinger also mounted on said shaft adapted to trip said dog to allow said switch to return to its original position.

10. In combination, an oil-switch, a resistance, means for varying said resistance, a rotatable shaft, an arm carried by said shaft adapted to cooperate with said switch to close the same, a dog for holding said switch closed, means operatively connected with said shaft adapted to operate said resistance-varying means, and a finger carried by said shaft adapted to trip said dog to allow said switch to open.

11.. In combination, an oil-switch, a resistance, means for varying said resistance, a shaft capable of rotating in one direction only, ratchet-and-pawl mechanism for preventing a reverse movement of said shaft, an arm carried by said shaft adapted to coact with said switch to close the same, a dog in dependent of said shaft for holding said switch closed, means operatively connected with said shaft for operating said resist-ancevarying means, and a finger carried by said shaft adapted to trip said dog to allow said switch to open.

In witness whereof I have hereunto set my hand this 17th day of April, 1902.

ARTHUR H. ABELL.

Witnesses:

BENJAMIN B. HULL, HELEN ORFORD.

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