US768566A - Electric controller. - Google Patents

Description

PATENTED AUG. 23, 1904.

B em. 6 v 8 6 7 m N APPLICATION FILED JUNE 4, 1904.

N0 MODEL.

UNITED STATES} Patented August 23, 1904.

MINER S. HORTON, OF ROCHESTER, NEW YORK.

ELECTRIC CONTROLLER.

SPEGIFICATIONfOrming.part of Letters Patent No. 768,566, dated August 23, 1904. Application filed June 4, 1904. SerialNo. 211,122.. (No model.)'

T0 at whmn it may concern:

Be itknown that I, MINER S. HORTON, a citizen of the United States, residing at Rochester, in the county of Monroe and State of New York, have-invented a new and Improved Electric Controller, of which the following is a specification.

This invention relates to that class of electric controllers in which the speed of the motor is made use of through the mechanism of a centrifugal governor carried thereby to gradually cut out resistance in series with the armature as the speed of the motor increases until at nearly thenormal speed of the motor forthe potential impressed all of the resistance is cut out by the action of such governor.

My present invention pertains more espe cially, in connection with such an arrangement of centrifugal governor and rheostat as just above described, to means for permitting the contact-arm of such a rheostat to return to that point in its travel where the maximum resistance is cut into circuit. with the armature of the motor immediately upon an opening of the circuit, preferably, though not necessarily, of both the field and armature circuits of such motor.

In carrying out my invention I prefer to make use of a rheostat of substantially the usual construction, with the contact-arm thereof provided with some mechanism, such as a weight or spring, tending normally to return such contact-arm to the point in its travel where the maximum resistance is cut into circuitwith such armature. Instead of operating this switch-arm of the rheostat directly from the centrifugal governor I prefer to operatea second arm directly by or from the centrifugal action of the governor and to se' cure an electromagnet1c connection when desired between this second arm operated directly from the governor and the switch-arm proper. For this purpose it is preferable that a portion at least of the second arm and the switch-arm constitute a magnetic path and that there be carried by one of such members an electromagnet having its exciting-coil encircling a portion of the mass constituting such magnetic path. The normal tendency of the rheostat-arm proper to return to its initial or starting point cutting inmaximum resistance in series with the armature is overcome by themagnetic attraction between the switch-armv proper and the secondary arm acted upon directly from the governor when the energizingcoil is in circuit with a suitable source of electric energy, and immediately upon opening such'circuit the switch-arm returns to its initial position, cuttingin maximum resistance in series with the armature. At this ti me by means of a suitable pole-changer the armature-circuit of the motormay be reversed and the armature caused to revolve in the opposite direction, which of course can occur only after a brief stop of the armature, at which time the centrifugal governor is brought to its neutral or initial position, also carrying with it the secondary arm, and thereby closing mechanically the magnetic circuit between the switch-arm and the secondary arm. Then upon closing the circuit of the energizing-coil for such switch-arm as the motor starts up to revolve in the opposite direction the switch arm proper, carried by and with the second arm,

is caused again to cut out successively differentisections of the resistances in series with the armature, allowing the same to again reach its full speed in the opposite direction.

The accompanying drawings, illustrating my invention, are as follows:

Figure 1 is an elevation of my controller and shows also connected therewith in both mechanical and electric diagram a motor and the necessary. switches and mechanism for opening and closing the circuits in the manner above described. Fig. 2 is an elevation of the controller proper, showing the parts thereof in the positions which they assume When the motor is running at maximum speed in either. direction. Figs. 3 and 4 show details to be explained.

Similar letters and figures refer to similar parts throughout the several views.

Ais an armature of a motor, having brushes a and a bearing upon the commutator thereof in the usual way. O is the field of such motor, from which the wire 7 leads to one terminal of the. coil of magnet m, while from the. otherterminal of the coil of magnet m wire 8 leads-to contact 0 of the switch From the pivotal point of this switch 19 wire 4 leads to the brush (4 The pivotal point of switch p is connected by wire 2 with one end of the rheostat R, having five contact-points and, of course, four sections of resistance. The norinalposition of the switch-arm V, pivoted at o, is, as indicated in Fig. 1, upon the contact 0 cutting the entire resistance R in series with the armature A. For maintaining such arm V in its normal initial position any desired mechanism may be made use ofsuch, for instance, as a weight w, seen on a horizontally-disposed arm connected to or formed integrally with this switch-arm V. Swinging upon this same pivot o is seen the secondary arm E, having its lower end connected, by means of the link a, with the lever 7L, arranged to be held to the left, as indicated, by means of the spring i. This lever h is pivoted at f and has the usual gibbed connection with the slidable element S of the centrifugal governor G, carried by the shaft y and caused to revolve by means of the belt 6, passing over a suitable pulley on such shaft y and also over another pulley on the shaft 0 of the armature A. This secondary arm E is curved, as indicated, and carries at its upper end an electromagnet m, the energizing-coil of which has connection such as already described.

F and F constitute the main feeders, which are connected, respectively, by means of Wires 1 and 5. to the pivotal points of the doublepole main switch T, through which the feeder F" may be connected, as seen, to the contactpoint 0* and by means of wire 8 to one terminal of the coil of magnet m, while the feeder F may be connected, as shown, to contact-points c, 0, 0 and 0 The two switch-arms p and p constitute the two arms of a pole-changer of the usual construction, and arranged to be operated simultaneously therewith is seen the switcharm 19 arranged to bear upon either the contact 0 or contact 0 It will at once be understood that by moving arms 19 p, and p to the right from the position shown in Fig. 1 will result in opening the circuit of armature A and also the circuit containing the coil of field-magnet C and the coil, of magnet m. Tis shown as closed in Fig. 1, so as to start the armature A of the motor, which begins to revolve and causes the govereor G to revolve alsotherewith. As the speed of the armature A increases the centrifugal action of the governor G causes the slidable member S thereof to be carried to the right in the usual Way, thus carrying with it the upper end of the arm it against the action of the spring 2', and by means of the connecting-link (t the secondary armE is caused to swing over tothe left, carrying with it the switch-arm proper, V, and as the rotation of the armature. A increases this action continues until at maximum speed for the armature A all of the resistance R is out out of circuit with the armature A. WVhen it is desired to stop the motor, the switch-arms p p p are moved to the right to neutral or open positions, at which time the magnet on is deenergized, permitting the arm V to return to neutral position against its stop Z, cutting in maximum resistance in series with the armature A, and as the motor slows down the action of the spring causes the parts of the centrifugal governor G to assume their initial positions, such as seen in Fig. 1. Immediately upon moving the switch-arms p, p, and p still farther over to the right the direction of the current through the armature A is reversed, while the coil of field-magnet C and also the coil of magnet m are again energized in the same direction as before, causing the armature A to again revolve in the opposite direction, at which time the action upon the centrifugal governor is the same as already described, causing the parts of my controller to assume the positions, respectively, such as indicated in Fig. 2 for maximum speed of the armature A.

The relative positions of the parts of my controller-via, the secondary arm and the switch-arm proper-immediately upon opening the circuit and before the armature A has slowed down any are indicated in Fig. 2, where the secondary arm E has been moved over to the left to its extreme position, and the magnet m having been deenergized the switch-arm proper, V, is permitted to return to its initial position (indicated in dotted line at VI in Fig. 2) against its limiting-stop Z.

Refer now to Figs. 3 and 4:, which show a detail of the last contact r. hen all the resistance has been cut out by the movement over to the left of the switch-arm V, this switch-arm V, carrying the usual carbon contact-brush 0, held in position by the spring 0, is caused to engage the right-hand end of the spring-actuated plunger 6, which is, as indicated, by means of the flexible connector 9 in electrical contact with the last contact 9* of the series of contacts 7, 1*, r W and r of the rheostat. This plunger 0 is normally held to the right by the action of the spring 02, contained within the barrel like extension 20, formed on an upwardly-extending arm of the contact 0'. Slight changes in the speed of the motor when at practically full speed are such as to cause a continual movement to and fro of the brush-arm V and the contact-carbon 0 on the last contact 0 of the rheostat R, and this last contact 9 is for this reason extended so as to cover a reasonable amount of such angular movement of the switch-arm V, and

were it not for the mechanism just described such slight movements to and fro of the switcharm V would cause a continual wearing of the carbon contact 0, which would in carrying the current be considerably greater than when not carrying the current or any considerable portion thereof, and such continual movement to and fro would also cause more or less areing between the carbon 0 and the contact 0'. To overcome this objection,the spring-plunger is provided, arranged to be held to the right, as indicated, against the switch-arm .V by the action of the spring a. In Fig. 3 this plunger e is seen as engaged by the switch-arm V and somewhat to the left, while in Fig. ithe normal position for this spring-plunger e is indicated and the switch-arm V is shown as over to the right and away from the contact r.

WVhat 1 claim is 1. Two main feeders, connected up in series between such feeders an armaturea resistance and a movable switch-arm arranged to bear upon successive contacts connected to different pointsin such resistance, means operating to retain such switch-arm at that point in its travel cutting in maximum resistance in series with such armature, a centrifugal governor mechanically connected to such armature, a first element of an electromagnet carried by such switch-arm, a second element of such electromagnet carried by the movable element of such governor, such first and second elements of such electromagnet having coincident paths whereby when such electromagnet is energized such switch-arm is caused by the movable element of such governor to pass over and engage successive contacts connected to such resistance according to the speed of such governor, and means for energizing and deenergizing such electromagnet as desired.

2. Two mam feeders, connected up 1n series between such feeders an armature a resistance and a movable switch-arm arranged to bear upon successive contacts connected to diiferent points in such resistance, means operating to retain such switch-arm at that point in its travel cutting in maximum resistance in series with such armature, a centrifugal governor mechanically connected to such armature, an electromagnetic connection between the movable element of such governor and such switch-arm operating when energized to cessive contacts connected to such resistance, cutting resistance in and out of series with such armature according to the speed of such armature and governor carried thereby, and means for energizing and deenergizing as desired such electromagnetic connection between such switch-arm and the movable element of such governor.

3. Two main feeders, an armature and a rheostat having a movable switch-arm connected in series between such main feeders, acentrifugal governor mechanically connected to such armature, such switch-arm connected to such governor and arranged to be operated thereby, an elongated final contact for such rheostat cutting out all the resistance therein from in series withsuch armature, such elongated contact arranged to engage such switcharmat all times throughout the entire range of its movement caused by variations in the speedof such armature due to fluctuations in the load thereon or in the line potential, an elastic or yielding connection between the main circuit and such switch-arm independent of such final contact and arranged to move with and thus connect such switch-arm to such main circuit at all times when in engagement with such elongated final contact.

' MINER S. HORTON.

Witnesses:

CLARA M. SIEUER, OSBORNE H. GURNEY.

I cause such switch-arm to travel over such suc-

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