US1040292A - Electric controller. - Google Patents

Description

A. 0. EASTWOGD. ELECTRIC CONTROL LEE APPLIUATION FILED $358124, 1910. RENE WED JULY 16,1912.

- Patented Oct. 8, 1912 2 SHEETS-SHEETI.

FIG. 1

WITNESSES iNVENTOR ,9

I AM/24M g7 m EAS- 790B" ELECTRIC CO1? APPLIQATIQE FILED 322m 1910. 1,040,292'

TEOLLER.

RENEWED JULY 15, 1912v UNITED STATES: PATENT OFFICE.

(I. EASTNOOD, OF CLEVELAND, OHIO, ASSIG-NOR TO THE ELECTRIC CGN- TEOLLER AND MANUFACTURING COMPANY, OF CLEVELAND, @515), A CQR?OIEIA TIDN 9F @HIO.

ELECTRIC CONTROLLER.

specification of Letters Patent.

Patented Oct. 8,191.

Application filed September 24, 1910, Serial. No. 588,577. Renewed July 15, 1912. Serial No. 709,575.

To all whom it may concern."

Cleveland. in the county of Cuyahoga and State of Ohio, have invented new and usetul improvements in Electric Controllers, of?

which the following is a specification.

My invention relates to electric controllers of that type in which a series of individually I operated switches are employed in control-; ling the [low of current in an electric circuit or circuits. In controllers of this t pe, to carry out a given scheme of control, it is necessary, or at least advisable, to provide means for compelling the various switches to close in an invariable sequence to carry out the scheme of control for which the controller is specifically designed.

My invention relates particularly to means for compelling such invariable sequence in the closure of a series of independently operated switches.

My invention. in addition to making the closure of one switch depend upon the closure of a switch which precedes it in normal operation, goes further than this and provides means whereby the succeeding switch cannot close not only till the preceding switch has closed, but till the circuit controlled by the preceding switch has closed. This I consider a point of material improvement over controllers in which the closure of one switch is made to depend upon the closure of the preceding switch, but such closure does not depend on whether or not the circuit through the preceding switch is closed.

My invention has the further advantage that so called auxiliary or control circuit contacts are removed from the switches which control the main. circuit connections. Referring to the accompanying drawings,

Figure 1 is a diagrammatic view illustrating my invention. in connection with a simple non-reversing controller for a series-Wound motor. Fig. 2 is a sectional View partly in elevation of a form of relay which is adapted for use in my invention.

On Fig. 1, S is a main switch connecting the motor and the controller to a source of current supply. A is the armature of the motor; F, the series field winding; R, R and R, sections of resistance adapted to he successivelyconnected in the controlled circuit. These sections of resistance are governed respectively by the magnetically-oper- Be it known that l, Anita-inn C. l l-is'rwoon, j a citizen of the United States, residing at ated switches S, S", and S. Vvhen switch S is closed, the resistance section B is in series with the motor. When switch S closes, the resistance section R is placed in parallel with the resistance R, thus reducing the resistance in the motor circuit. \Vhen switch S closes the resistance section B is connected in parallel with resistance sections R and R thus further reducing the resistance, and when the switch 3* closes, the entire resistance is short circuited through the wire 4. The switches S to 5* are provided with actuating windings C to C, respectively. M indicates a master switch of the drum type, by which the windings ot' the switches may be successively energized at the will of the operator by turning the drum of the switch so asto bring the contact strips n to 9 successively into contact with the stationary contact fingers m to m, respectively. The lower ends of each of the actuating windings of the magnetic switches are connected, respectivel), to the contact fingers m to'm of the master switch. Each of the switches S to S is provided with a series relay, the winding of which is included in the circuitclosed by the switch. Each of these relays controls a pair of normally open contacts such that when current flows through the winding of the relay, these contacts are bridged and electrically connected together. It will be seen that the contacts of the relay L are included in the circuit of the winding of the switch S"; the contacts of the. relay L are included in the circuit or thcwiirling of the switch S and the contacts of the rclay L included in thecircuit ()f the winding of the switch S.

The operation of this controller may be described as follows: Assuming tha the main switch S is closed and that the (m ni of the masterswitch or controller is moved to bring the contacts or and '21. into contact with the respective fingers 1a and m, the; following circuit will be established: from the positive side of the switch S through. the wire 1, the finger m of the master switch, the contact strips 1i and n, the contact linm the winding C of the switch S, and... the wires 5 and 3 to the negative side. of the switch 5. This completes the circuitthrough the winding of the switch S which will then,close. The circuit through the v sistance in the motor circuit.

controlled by the switch S includes the motor is then completed as follows: from the positive side of the switch S through the wire 1, the contacts bf the switch S', the winding of the relay L, the resistance section ll, the wire 2, the field F and the arma' ture A of the motor, and the wire 3 to the negative side of the switch S. Current thus flows through the winding of the relay L which lifts its plunger and bridges the contacts 'a.

W hen the master switch is moved into its next position, that is, when the strip a is brought into contact with the finger m the winding C of the switch S is energized through the following path: from the positive side of the switch. S, through the wire 1, the contact finger m, the contacts n, 9%., and a of the master switch, the finger m the winding C of the switch S the contacts a of the relay L, and the wires 5 and 3 to thenegative side of the switch S. The switch S then closes, thus connecting the resistance section R in parall" with the resistance section B", reducing the totalre- The circuit winding of the relay if, and if this circuit is complete, that is to say, if there are no broken connections in the circuit controlled by the switch S the winding of the relay L will be energized, and this relay will lift its plunger, thus closing the contacts a which are in the circuit of the winding C of the switch S which is the next switch to close. Similarly, by further rotation of the drum of the master switch, the switch S is caused to close, thereby energizing the relay L and putting the switch S in a position to be closed, ,upon moving the master switch another step. When the switch 5 closes, all of the resistance is short circuited, current then flowing through the motor as follows:

from the positive side of the switch S,

throughthe wire 1, the winding of the relay U, the contacts of the switch 5*, the wire 4, the field and the armature of the motor, and the wire 3 to themegative side of the switch S. The closure of the switch S", therefore, in addition to short circuiting resistance sections R, R and R also short circuits the windings of the relays L and L These two relays, therefore, drop their plungers and the switches S and S automatically open. The switch 8*, however, is maintained closed through the contacts of the relay L since the motor current flows through the winding of this relay.

"When it is desired to stop the motor, the drum of the master switch is turned back to its initial or ofi-position, which causes the switch S5 to open and interrupt the motor circuit.

adapted to switches, or they may be shunted so that any desired portion of the motor current will flow through the relay windings. I have. indicated at K a shunt-around the winding of the relay L By properly proportioning the resistance of this shunt with respect to the resistance of the winding .of the relay L any desired proportion of motor current may be causedto flow through the relay form, the additional valuable result may be obtained of preventing successive closure of the switches until the current taken by the motor has dropped to a suitable value; in other words,succeeding switches will not close unless the motor'current is below a predetermined value. By this means the current taken by the motor during acceleration may be made substantially constant and independent of the rapidity with whichthe operator moves. his master controller. Where it is desirable to do so, the master controller, having a con-tact for each switch, -may be replaced with a simple switch controlling the circuit of the switch S, the other switches closing automatically in predetermined order and only closing when the current taken by the motor is at a predetermined and proper value.

In Fig. 2 l have shown a form of relay the purposes of the relays L to L In this relay 6 is a frame of magnetic material, the upper portion of which is provided with a central depending pole piece 12 K is the winding of the relay adapted to-beconnected as indicated in Fig.1. 6 is a core of magnetic material provided with a stem or extension 6 also of magnetic material. This stem 6 extends into the bore of a hollow adjustable plug 6 of mag netic material. The upper end of the core I) 'is provided with an extension Z1 of brass or other non-magnetic material. This extension'carries at its upper end a contact disk 6 suitably insulated from the stem. and adapted to bridge or connect the stationary. contact points 6 and 6. The shoulder 6 serves to limit the downward motion of the core. This relay possesses the remarkable characteristic that, if a current at or below a predetermined value flows through the .winding K, the core 6 will be attracted to the boss 5 thereby causing the relay to face the plug; Z) and the core will not until the current has been reduced to the said prede ermined value. The value of current at which the relay will act to bridge its contacts may be adjusted in various ways, but preferably by the air gap bet "eon the face the plug and the lower face of the core 6*, this being accomplished by screwing the plug 1 in or out.

Y the switch shown in Fig. 2, the mag netic flux appears to tow in a divided path in a part oi the magnetic circuit, when the winding energized. The magnetic flux may be regarded flowing from a point in the frame T), such as the pole across the air ap inin'iediately below the pole and into the core Zr. At the lower end of the core the fill}: divides into two paths, one path through the core-extension 5 and into the plus J and the lower end 01 the me and the other path being from the lower end of the core b across the air-gap immediately below it and into the top of the plug 72 and thence through the plug to the lower end of the frame Z). The flux i the upper gap produces a "ce tending to raise the core 71*, While the i'i lK. through the lower gap produces a force tending to prevent the core from being raised. H the winding is excited a relati vely low value, the larger part of the flux; produced thereby will flow through. the extension 6 and since this flux passes horizontally into the frame, there is no tendency to prevent the plunger from moving upwa dly, only a small part of the flux passing across the lower gap around the extension 5 the winding is excited at a high value the restricted area in the magnetic circuit through the extension forces more llux to pass across the lower gap into the plug or pole 5, thereby increasing the force tending to prevent the upward movement of the core. The extension Z) is in the said applications oi Cantield surrounded by a sleeve of non-magnetic material which serves as a guide tor the core and prevents the core vfromsticking to the pl ugb l disclaim the specific construction of this r lay as part of this invention as the same is the invention of Harry R. Canfield and tor-ins the subject matter of his [applications tor il'nited States Patent, Number SHEWO tiled trleptcinber 21, 1910', and Se I :51, tiled January i5) rial Number 30 H, n, do. how-o'er, claim @combinatiou including; this reuiy or its equivalent connected 'l minted in Fig. l, or in modified ways rezuily suggest themselves to iii skilled in the a 1 rice now to Fig. 1, with the relays L to L constructed as shown in Fig. 2, as some that the operator moves his master switch suddenly to the full speed position, that is, until all of the contact strips n to a are in contact with their respective fingers m to m". A circuit is then completed through the winding G of the switch S, causing this switch to close. 1n closing the switch S closes the main motor circuit through the winding of the first relay L. It the current which then flows is greater than that for which the relay is adjusted, the relay cannot lift its plunger and the winding C of the switch remains deenergized. When, however, the motor current has fallen to a safe or predetermined value, the relay lifts its plunger, thus brid i ing the contacts a and completing the circuit through the winding C of the switch main or motor circuit through the winding of the relay which in a similar manner cannot permit the closure of the switch S until the current has dropped to a prede termined value, 11 the current exceeds the value 7 which the relay L is set. The relay L acts in a similar manner to prevent the closure of the switch S until the current has dropped to a predetermined value.

With the described scheme of control, the operator may control the number of switches closed by the position to which he moves the master switch, but he cannot, however, control the rate of progression of the closure of the switches since the rate is governed by the motor current through the agency of the relays L to L; nor can he cause the switches to close out of their predetermined order, which is also determined by the relays Li to L. lit will be understood that, if open circuits exist in any or the resistance sections R, R and R or their connections, the successive closure of the switches will be interrupted when this point is reached in the acceleration and the motor cannot be brought up to full speed until the trouble is repaired. For instance, if there should be an open connection in the circuit of the resistance section R when the switch closes, no current could flow through the winding of the relay L consequently, the winding of the switch S cannot be energired until the trouble is remedied. Similarly, if there is an open circuit in-the connection including the resistance section R no current could flow through the winding of the relay L even though the switch S is closed; consequently, the switch S could not be closed.

clain ln electric controller, the combination of a series of magnetically operated switches to be successively closed, the circuits of the actuating windings of the said magnetically operated switches being in The switch S then closes, closingthe' iiu shunt with or derived from the controlled circuit, and means for preventing further successive closure of said switches in case any one of said switches when closed fails to establish a circuit through its main contacts.

In combination, a series of magnetic switches each adapted to close a pair of main contacts, each of said switches having an actuating winding independent of the circuit controlled by said main contacts, and means for preventing the closure of succeeding switch unless current flows through the main contacts of the switch which precedes in operation.

3. The combination, in in electric controller, of a series of switches each having main contacts and an actuating winding, relays associated with certain of said switches and having normally open contacts in the circuit of the winding of the switch next to close, said relays having windings arranged to be successively connected in the controlled circuit hy the closure of the main contacts of the said switches and movable contacts on said relays actuated by the said windings to close the said normally open contacts.

st, in an electric controller, a series of magnetically-dperated switches to be suc cessively closed, means for inforcing said successive closure, said means comprising normally open contacts in the circuit of the winding of each of said switches except the first to operate, a relay for each of said normally-open contacts, said relay being ar ranged to connect said contacts when its winding is energized, the winding of the relay controlling the contacts in the circuit of the winding of thesecond switch being in cluded in the controlled circuit by the closure of the first switch, the winding of the relay controlling the circuit of the winding of the third switch being included in the controlled circuitloy the closure of the sec- 0nd switch.

5. In an electric controller, a series of consecutively-acting magnetic switches, a relay adapted when energized to close the circuit through the actuating winding of each of said switches, except the first to close, each of said relays being included in the controlled circuit by the switch which precedes in operation.

6. In an electric controller, a series of consecutively-acting magnetic switches, a relay arranged to control the circuit through the actuating winding of each of said switches, except the first to close, each of said relays being included in the controlled circuit by the switch which precedes in opration, said relays havin, normally open Contacts being constructs to close their contacts only when the current through their windings is less than a predetern'nned amount.

notc es 7. The combination, in an electric con troller, of a series of switches each having 8. The combination, in an electric conc troller, of a series of switches, each having main contacts and an actuating winding, re lays associated with certain of said switches and having contacts in the circuit of the winding of the switch next to close, said relays having windings arranged to he successively connected in the controlled circuit by the closure of the main contacts of said switches, each of said relays having normally open contacts being so constructed as to close its contacts only when the current through its winding is below a predetermined value, and means for adjusting the said relays as to the current value at which they will close their contacts.

9. In an electric controller, a series of magnetically operated switches to be successively closed, means for iniorcing their successive closure, said means comprising normally open contacts in the circuit of the winding of each of said switches except the first to operate, a relay for each of said normally open contacts, said relay being ranged to connect said contacts when ts winding is energized by a current below a predetermined value, the winding of the relay controlling the contacts in the circuit cf the winding of the second switch heing in cluded in the controlled circuit by the clo sure of the first switch, the winding of the relay controlling the circuit of the winding of the third switch being included in the controlled circuit by the closure of the sec ond switch, and so on.

10. In an electric controller, a series of magnetically operated switches to he succea sively closed, means for intorcing their successive closure, said means comprising normally open contacts in the circuit of the winding of each of said switches except the first to operate, a relay for each of said normally open contacts, said relay being ar-- ranged to connect said cont-acts when its winding is energized by a current below a predetermined value, the winding of the relay controlling the contacts in the circuit of the winding of the second switch being included in the controlled circuit by the ole sure of the first switch, the winding of the rela controllin the circuit of the'windin ,1 operation, each of said relays being so constructed as to close its contacts only when an LAG u rent through its winding is below a ermined value.

in an electric controller, a series of consecutively acting magnetic switches, a rec third switch being included in the lay adapted when energized to close the circuit through the actuating winding of each of said switches except the first to close, each of said relays being included in the controlled circuit by the switch which precedes in operation, each of said relays being so constructed as to close its contacts only when the current through its winding is below a predetermined value, and means for adjusting said. relays as to the current value at which they will close their contacts.

Signed at Cleveland, Ohio, this 19th day 30 of September, 1910.

ARTHUR C. EASTWOOD.

Witnesses:

J. H. HALL, H. M. DIEMER

Images