US507547A

US507547A - Series multiple electric controller

Info

Publication number: US507547A
Authority: US
Publication date: 1893-10-31
Anticipated expiration: 1910-10-31

Description

(No Mbdell) 3 Sheets-Sheet 1.

A. P. KNIGHT. SERIES MULTIPLE ELECTRIC GONTEOLLEE. No. 507,547. Patented Oct. 31, 1893.

WITNESSES: LINVENTOR: Mum PJ'CVQW ATTYS (No Model.) 3 Sheets-Sheet 2.

A. P. KNIGHT. SERIES MULTIPLE ELECTRIC CONTROLLER. No. 507,547. Patented OCt. 31,1893.

WITNESSES:

(No Model.) 3 Sheets-Sheet 3.

A. P. KNIGHT.

SERIES MULTIPLE ELECTRIC CONTROLLER.

' UNITED STATES PATENT OFFICE.

ARTHUR P. KNIGHT, OF BOSTON, MASSACHUSETTS, ASSIGNOR TO THE THOMSON-HOUSTON ELECTRIC COMPANY, OF CONNECTICUT.

SERIES MULTIPLE ELECTRIC CONTROLLER.

SPECIFICATION forming part of Letters Patent No. 507,547, dated October 31, 1893.

I Application filed January 26,1892. Serial No. 419,268- (No model.)

To all whom it may concern.-

Be it known that I, ARTHUR P. KNIGHT, a citizen of the United States, residing at Boston, county of Suffolk, State of Massachusetts, have inventeda certain new and useful Improvement in Series Multiple Electric Controllers, of which the following is a specification. I

This invention relates to means for con-trolling electric motors, and for transferring-such apparatus from series to multiple relation,or vice' versa, without at any time wholly breaking the circuit of either-of such motors. For this purpose supposing the devices to be in series, a connection is made around each of them, from their line terminals to theirjunction terminals, such connection including a resistance sufficient to prevent short-circuiting of either the devices or the line itself.

This resistance is in fact preferably such that under the normal conditions of use at the time of transfer, each resistance branch will take about the same current that passes through each of the electric devices. This being the case, the junction between the motors will carry little or no current and may then be severed without materially changing the circuitccnditions, and therefore without great sparking.

My invention is designed particularly for use on constant potential circuits, and more especially for transferring a pair of electric motors connected to such circuit, from series to multiple relation, or Vice versa. It is applicable for instance to the case of an electric railway car driven by two motors, which are thus connected to a common load, it being desirable to change the relation of such motors as aforesaid, to effect the changes in speed.

In the accompanying drawings Figure 1 is aplan view of a switch and circuit connections adapted to carry out my invention. Fig. 2 is a vertical section of the switch. Figs. 3, 4, 5, 6, and 7 show successive positions ofthe switch after it has left the open position of Fig. 1. Fig. 10 shows in diagram the electrical con nections for the several positions of the switch.

L, L may represent constant potential lines; or connections to a constant potential tute in effect movable line terminals. contacts 1*, r r are connected together and Figs. 8 and 9 show modifications,-andswitches for similar purposes are now common in the art and are made up in many different .designs, such as the cylinder form,

the disk form and the lever form. Any one of these forms may be adopted as found most convenient. I have shown the lever type of switch,tofacilitateexplanation. Itcomprises a handle or actuator H, a cross arm C and two insulated terminals t, t, all connected mechanically together, as by being mounted on a disk or carrier 0 pivoted at 0. The opposite ends of cross arm 0 traverse respectively the two series of contacts r,r ,r r ,r r located respectively adjacent to contacts 0, c. The terminals 25, t traverse said series of contacts, and

contacts

0,0, and simultaneously bear upon the segments Z, Z which being connected to the line terminals of the motors M, M, cause the pieces t, t to consti- The to contact 0 by resistances R. Similar connections to resistance R are made between contacts 4", r r, and c.

Fig. 1 represents the switch as in the open position, the cross arm C being slightly behind the first contacts r, r, and the arms 2 ,15 being still further behind,and, preferably out of contact also with the line segments-l, Z. The circuit of both the motors is now open. On turning the switch to position of Fig. 3, the motors are placed in series with each other and with all of the resistances, the circuit being as follows: line L, motor M, contact 0, resistances R, contact 4, cross arm C, contact r resistances R, contact 0, motor M, line L. The resistance so introduced has the beneficial effect of preventing undue rush of current to the motors in starting, and more or less of it may be left in, to give a very slow speed, or the switch may be turned to positionof Fig. 4, where all of the resistances are It is ob-- cut-out, the motors being directly in series through the cross bar. In this position arms 25, t are near, but not in contact with the initial contacts 0", 7. Now to transfer the motors from series to multiple connection, the switch is further turned, and passing into position of Fig. 5, brings arms or movable line terminals 15, t on to contacts 1", 1, before contact is broken between cross arm U and contacts a, 0. Two circuits can then be traced, one as before, through the motors and cross arm, another from line L to connection 1, line segment Z, arm 2?, contact 4", resistances R, contact 0, cross arm 0, segment Z, connection 2 and out to line L. The current in the first circuit is determined by the electromotive force of the line, the resistance of the motors and the counter-electromotive force of the motors. The current in the second circuit is determined by the line potential and the resistances. Assuming a that the transfer will generally be made under certain conditions of motor-speed, t. 6., at

about a'certain cou nter-electromotive force, it

is apparent that the resistances R, B may be so proportioned that the currents flowing in I the two circuits above traced shall be about equal. the current pass through the cross arm 0 in opposite directions, so that with the aforesaid substantial equality there would be little or no current passing through said cross arm, each motor in fact being supplied with current only through the rheostat R or R connected to the other side of the circuit. Un-- the motors are in multiple with a resistance in series with each, and byfurther movement of the switch this resistance, or so much of it as desired, may be cut-out, the switch coming finally to position of Fig. 7, with the motors in simple multiple connection.

In Fig. 10 therespective diagrams a, 19,0, (Z, c, show the circuits under the several conditions above described. In diagram athetwo motors are in series with the two resistances, in diagram bthey are in series without resistance, in diagram 0 each motor-is shunted through the resistance, in diagram 01 the immediate connection between the motors is severed, and each motor is inseries with a resistance, but in multiple with respect to the other motor, while in diagram 6 the two motors :are in multiple without resistance.

Independently of the exact or even approximate neutralization of the current in the But the said two circuits or-paths for cross arm, or junction, it will be seen that this controller has the advantage of always leaving a path for the field magnet discharge, so that if the current through the motor is weakened, the energy of extra current discharging from the field magnets is taken up in a closed circuit.

Of course in applying this invention to electric railway service, it would be used in conjunction with any usual or suitable de vices to supplement its action, for example, reversing contacts or switches for the motor armatures or loop connections for the fields. Thus in Fig. 8 are shown resistances R R shunting the field magnets and connected to extra or final contacts 8, s, so that when arm 0 or arms t, t bridge the contacts 0 s, 0' 8 11119 motor field magnets are partially shunted, giving a well known accelerating effect.

In Fig. 9 extra resistances R R are connected between contacts 0 s and c s,so that they are introduced into the cross connection before breaking the same, and the liability of a heavy current being broken is still further diminished. This extra resistance intro duced before breaking may be of any usual or suitable magnitude, and may of course be introduced in sections. Similarly the two series of resistances 7'', r &c., may be divided up into anydesirable number, or each series may constitute only one resistance. In that case, with the form shown in Fig. 1, only contacts c, c, and contacts r, 0"", would be necessary, a single resistance R connecting c and r and another resistance R connecting c and r, the contacts being, however, in any case so placed that the switch arms do not break in passing from one to the other.

In case it is desired to regulate the mechanical action of the switch, so as to prevent its too rapid manipulation, or to cause it to come to rest with certainty in certain normal stopping and running positions, suitable clevices for these purposes may be employed. Thus in Fig. l are indicated in dotted lines, a ratchet wheelw and spring pawlw', which engage in obvious manner to prevent dangerously rapid rotation of the switch, and also to hold it in to certain definite positions, such as the open position, a series resistance position, the full series position, and the full multiple position. This snapping action of j the switch can be facilitated by the interposition of a lost motion connection between the actuator I1 and the switch proper. It will also be understood that a single switch may be actuated in auysuitab'le manner from'controlling hand levers at each end of the car, and may be placed in any suitable location on the car, or duplicate switches may be pro vided at opposite ends of the car. In any case the switch may be provided with duplicate cross connected setsof contacts and reversing contacts in order to reverse the connections of the armature in well known manner. It is obvious also that the motors when open circuited maybe altogether disconnected from the lines, the circuit being closed to each motor only as the switch comes to the position indicated in Fig. 3. Thus when the motors are stated to be connected to the lines, it does not mean that such connections are permanent, but that they exist during the process of changing the connections of the motors in accordance with this invention.

I am aware that it has been heretofore proposed to change motors on a constant potential circuit from series to multiple relation for the purpose of regulating the power and speed of the mechanism driven by such motors in common, but the devices originally suggested for effecting such a change in the relations of the motors contained no provision for overcoming the difficulty presented by the destructive are which is produced by the rupture of the circuit ata time when between different parts of such circuit there existed a difierence in electro motive force arising either from the impressed electro-motive force of the line, the counter-electro-motive force or the self-induction of the motor. Subseq-uent inventors have, it is true, attempted to devise switching apparatus for effecting a change of the motors from series to multiple relation which would be free from objection on account of the aforesaid difficulty. One plan for securing the desired results contemplates the insertion of a sufficient resistance to reduce the line current to a minimum at the moment of making a change in the connections, but such an arrangement introduces the further difliculty that the driven mechanism must be momentarily deprived of its motive power at each change, while the constant, use of a resistance is both wasteful of energy and causes excessive wear on the resistance contacts. It has also been proposed in a constant potential system to change an electric motor from series to multiple relation with a second motor, by first reducing its field magnet strength until it is practically dead; then establishing a connection around it, and finally disconnecting the motor from its series relation and changing it to a multiple relation with the other motor. In such an arrangement however, it has been found impossible to satisfactorily discharge the field magnetism, and apart from this difficulty it is to be also observed that when the shunting or short-circuiting connection is established the machine is in effect not a motor at all, but simply an inactive coil because it .has been deprived of the power to exercise the functions of a motor. I, therefore, for the purpose of distinguishing my invention from such a method desire it to be understood that wherever in the foregoing specification and, in the following claims I have stated that a.

Over the method mentioned above and over all others heretofore devised for the purpose of effecting the change of electric motors from series to multiple relation, I consider that the essential feature of my improvement resides in the fact that a connection is established around a motor from its line terminal to its junction terminal, while it is still active and prior to the severance of the series circuit that extends through the motors from one line to the other. After this connection has been established, the motor is in such condition that it is a simple matter to disconnect the shunted motor from its series relation with the other motor by any suitable switch, so that it may be included in a separate independent circuit, passing directly from oneline to the other either with or without a resistance included therein. By treating both motors in the same manner and suitably adjusting the resistance of the shunting circuits I I am enabled to effect without difficulty the desired change in the relation of the motors from series to multiple.

WVhat I claim as new, and desire to secure by Letters Patent, is

1. The combination with a constant potential circuit of an electric motor in series with a second motor on the said circuit, a separable connection for said motor, and a connection around it containing a resistance.

2. The improvement in the method of changing an electric motor from series to multiple relation with a second motor by interrupting the series circuit and establishing multiple circuits which consists in making a connection around the motor from its line terminal to its junction terminal prior to the interruption of the series circuit.

. 3. The improvement in the method of changing an electric motor from series to multiple relation with a second motor by interrupting the series circuit and establishing multiple circuits, which consists in making a connection containing a resistance around the motor from its line terminal to its j unction terminal prior to the interruption of the series circuit.

4. The improvement in the method of series multiple control involving the changing of an electric motor from series to multiple relation with a second motor by interrupting the series circuit and establishing multiple circuits, which consists in inserting a resistance in the series circuit and then making a connection containing the said resistance around the motor from its line terminal to its junction terminal prior to the interruption of the series circuit.

5. The improvement in the method of series multiple control involving the changing of an electric motor from series to multiple relation with a second motor by interrupting the series circuit and establishing multiple circuits, which consists in placing a resistance in the series circuit,-removing said resistance, and

making a connection including the said re- ICO IIO

sistance around the motor from its line terminal to its junction terminal prior to the interruption of the series circuit.

6. Theimprovementin the methodof series multiple control involving the changing of an electric motor from series to multiple relation with a second motor by interrupting the series circuit and establishing multiple circuits, which consists in placing a resistance in the series circuit, gradually removing said resistance,.and making a connection around the motor from its line terminal to its junction terminal prior to the interruption of the series circuit.

7. Theimprovement in the method of series multiple control involving the changing of an electric motor from series to multiple relation with a second motor by interrupting the series circuit and establishing multiple circuits, which consists in placing a resistance in the series circuit, gradually removing said resistance, and making a connection including the said resistance around the motor from its line terminal to its junction terminal prior to the interruption of the series circuit.

8. Theimprovement in the method of series multiple control involving the changing of an electric motor from series to multiple relation with a second motor by interrupting the series circuit and establishing multiple circuits, which consists in placing a resistance in the series circuit, removing the said resistance, making a connection including the said resistance around the motor from its line terminal to its junction terminal, changing the connections from series to multiple with the said resistance in series with one of the motors, and finally removing the resistance.

9. Theimprovementin the method of series multiple control of two electric motors which consists in regulating the motors while in series, then changing one from series to multiple relation with the other by first making a connection around it from its line terminal to its junction terminal, and then changing the connections and finally regulating the two in multiple.

10. Theimprovement in the method of series multiple control of two electric motors which consists in regulating the motors while in series, then changing one from series to multiple relation with the other by first making a connection including a resistance around it from its line terminal to itsjunction terminal, and then changing the connections and finally regulating the two in multiple.

11. The improvement in the method of series multiple control of two electric motors which consists in regulating the motors while in series by means of resistance, then changing one from series to multiple relation with the other by first making a connection around it from its line terminal to its junction terminal, and then changing the connections and finally regulating the two in multiple.

12. The improvement in the method of series multiple control of two electric motors which consists in regulating the motors while in series by means of resistance, then changing one from series to multiple relation with the other by first making a connection around it from its line terminal to its junction terminal, and then changing the connections and finally regulating the two in multiple by means of resistance.

13. The improvement in the method of series multiple control of two electric motors which consists in regulating the motors while in series by means of resistance, then changing one from series to multiple relation with the other by first making a connection including the same resistance around it from its line terminal to it-sjunction terminal, and then changing the connections and finally regulating the two in multiple.

14. The improvement in the method of series multiple control of two electric motors which consists in regulating the motors while in series by means of resistance, then changing one from series to multiple relation with the other by first making a connection around it from its line terminal to its junction terminal, and then changing the connections and finally regulating the two in multiple by means of the same resistance aforesaid.

15. The improvement in the method of series multiple control of two electric motors which consists in regulating the motors while in series, then changing one from series to multiple relation with the other by first making a connection including the same resistance around it from its line terminal to its junction terminal, and then changing the connections and finally regulating the two in multiple by means of the said resistance.

16. The improvement in the method of series multiple control of two electric motors which consists in changing them from series to multiple relation by first making a connection around each of the two motors from its line terminal to itsjunction terminal, and then changing the connections from series to multiple.

17. The improvement in the method of series multiple control of two electric motors which consists in changing them from series to multiple relation by first making a connection including a resistance around each of the two motors from its line terminal to its junction terminal, and then changing the connections from series to multiple.

18. The method of controlling electric motors and changing them from series to multiple, which consists in establishing a circuit including two motors, and two resistances all in series, then cutting out said resistances, thus making a direct series connection between the motors, then making a connection around each motor, including one of said resistances, then breaking said direct series connection and then cutting out the resistances from the resulting multiple connections.

19. The combination with two electric motors, of two resistances, connections including said motors and resistances, all in series, connections including said motors directly in series independently of the resistances, connections including each resistance in series with one of the motors and in multiple with the other motor, and circuit controlling devices in each of such connections.

20. The combination with two electric motors, of two resistances, contacts connected directly to said motors, contacts connected to said motors through resistances, a cross arm bridging the resistance contacts or the direct contacts alternately and movable terminals connected to the outer terminals, of the motors and engaging with said contacts.

21. The combination with a constant potential circuit, of two motors having outer connections to opposite sides thereof, and inner connections to separate contacts, two sets of resistances respectively connected to said innor connections and to separate contacts, a cross arm bridging said motor contacts or said resistance contacts alternately, and movable terminals connected to the outer connections of the respective motors, and making contact with the resistance contacts of the opposite motors while the cross arm is still in connec tion with the motor.

22. The combination with a constant potential circuit, two electric motors connected respectively thereto, a separable connection between such motors, and separable connections around each motor, each containing a resistance sufficient to prevent short-circuitln g of either the motors or the supply circuit.

23. The combination with a constant potential circuit, of two electric motors, separable connections connecting said motors in series in said circuit, and separable shunting connections around each motor and containing resistances, the total resistance of the path through such shunt connections having about the same ratio to the total resistance of the path through the motors, that the electromotive force of the line has to the efiective elec- 45 trornotive force through said motor path.

In testimony whereof I have hereunto set my hand this 21st day of January, 1892.

ARTHUR P. KNIGHT. Witnesses:

N. F. HAYES, H. J. LIVERMORE.