US936878A - Automatic controller. - Google Patents

Description

F. R. FISHBAGK. AUTOMATIC CONTROLLER. APPLICATION FILED JAN. 23, 1909.

- Patentgd 001;. 12, 1909.

ALI'TOHNEY UNIT D STATES PATENT orricn FREDERICK R. FISHIBAGK, F CLEVELAND, QHIO; ASSIGNOR-TO THE- ELECTRIG CON- TROLLER AND MANUFACTURING COMPANY, OF CLEVELANQ, OHIO, A CQB PORATION OF OHIO. I

new

AuToMAT'Ic CONTROLLER.

' Application filed January 28, 1996; Serial No; 473,840.

To all whom it may concern:

Be it known that I, FREDERICK R. FISH- BACK, a citizen of the United States, residin at Cleve1and,in the county of Ouyahoga an State of Ohio, havei-nvented or discovered new and useful Improvements in Automatic Controllers, of which the following is a specification. 1

My invention relates to a system of automatic control for electric motors having particular application to cases where it is desired to stop an electric motor airtomatically when the load driven thereby hasfeached any one of a number of giVenpoin'ts; the particular point'at which the load istobe" I stopped being, determined at the time of starting the motor.-

My-invention provides means for securing this result in a simple and reliable manner.

An example of the conditions which my improved system aof control is particularly designed to meet occurs in the case of an elevator wherein the car may be started from a stationary point and be made to stop automatically at a number of different landings which may not be in full view of: the person starting the elevator.

My inventionfwill be'more fully understood by reference to the accompanying drawing, which is a diagrammatic representation thereof;

A isthe armature of the driving motor; F, its series field winding; and F, its shunt .D and D U and U are switcheswhich close in pairs to determine the direction of rotation of the armature of the moto'r S is a magnetically operated switch, which,

when closed, completesfa local or dynamic braking circuit including the resistance R and the armature Aof the motor;

S, S and S?- are magnetically-operated switches which control the-sections of resistance R, R and R which are made use of in bringing the motor up to speed, The resistance controlling switches S, S", and S are under the control of a relay L, so arranged as to secure automatic successive closure of the resistance'switches 1n a well kIlOlVll 11131111181.

Patent, No.'867,810, granted to A 0. East wood, October 8, 1907. v v I 'X is a 'cnt-out switch having one end of Specification of Letters Patent. Patented 12, 1969.

the arm G connected by suitable gearing";

shown in dotted lines to the armature shaft of the motor A, or other part'of the moving mechanism actuatedby the motor, so that the.

arm shall assume definite positions corresponding to definite positions of the load.

The arm G has a contact brush H arranged to engage the fixed contacts a to g as the arm a to-gv are spaced apart relatively to the length of the brush so that the latter may span anyftwo consecutive fixed contacts, or when centrally arranged on anyfixed contact, will be ont of contact with the adjacent fixed contact on either side thereof. The contacts a to g are connected respectively by the wires 2 to 8 with the fixed. contacts a to g of the dial switch Y, which has --isldriven by the motor. The fixed contacts 7 a central disk B carrying the arc-shaped segments C, D, and E arranged to engage the contacts 'a'g' .The contact E is long enough to engage only one of the fixed contacts at a time. The switch Y has the handle I for moving the pointer J opposite any one of the contacts a to g.

' The segment E is connected by th'e'sf wire 12 to one end of the winding of the dygihfmic brakin switch S;-the segment I) is connected y the wire 9 to the wire 10,-whichis connected to one end of the windings of'lihc reversing switches D and D and the so 5 inch!) C is connected by the. wire 13 tot 1e wires 15 and 14, which lead to one end of the reversing switches U and U respectively;

The remainin ends ofthese five windings are connected y the wire l9.to'.the tnegntive wire 20. The arm G is connected bathe wire i 1 to the positive siderofthe line.

With the arm G of the cut-out switch X and the pointerJ on the dial switchY place/d as shown, a circuit is completed as follovs; from the positive side of the line, throu h the wire 1, the arm G, the contact a, 510

wire 5, the contact d, the wire 12, the winding of the switch S, and the wire 19 to the negative side of the line at 20.. Under this condition the dynamic braking switch S 5 would close, the diagram, however, showing its position just before closure. In order to start the motor, the operator moves the pointer J until it indicates the point corresponding to that at which he wishes the arm G to stop. Assume that he moves the pointer J so that it rests opposite the brush Y), the contact segment E is then in contact with the brush 6. The segment C is in contact with the brush a, and the segment D is in contact with-the remaining contacts 0 to g. In moving the segment E from the contactd, the circuit of the winding ofthe dynamic braking switch S is opened, causing this switch to open. The control circuit then passes from the positive side oft-he line through the wire 1, the arm Gr, the contact d, the wire 5, the contact d, the segment D, the wires 9 and 10 and one end of the windings of reversing switches D and D the wire-19 to the negative side of the line. This circuit obviously closes the switches D and D which complete the circuit through the motor as follows from the positive side of the line, through the resistance sections R, R and R the field F of the motor, the'switch D, the wires 17 and 18, the armature A of the motor, the switch D and thence to the negative main through the wire 21. .The motor should then start with all of the controlling resistance in its circuit. This resistance is subsequently automatically cut out by the switches S, S andS under the control of the relay L, thus bringing the motor up to full speed. As the motor revolves, the arm G of the cut-out switch X also revolves; but in revolving the control circuit is maintainedv through the windings of thereversing switches D and D when the brush H passes off from the contact d onto contact 0, the control circuit then flowing through the wire 1, the arm G, the contact 0, the wire 4, the contact 0, and the segment D on the switch Y to the-windings of the switches D and D as before; When, however, the contact H makes connection with the contacts 0 and 6, two circuits are established, one through the contact c, the wire 4, the contact 0, etc. to the windings of the switches D and D as above described. The other circuit is from the wire 1, through the arm G, the contact H, the contact 6, the wire 3, the contact I), the

segment E, the wire 12, and the winding of,

the switch S. This will tend to cause the BO-switch S to close but the mechanical interlock L will not permit it to close until the swi th D has opened. As the contact arm 0 travels farther it will atthe proper point of travel open circuit with the contact a,

which causes the switches D and D to instantly open, thus permitting the dynamic braking switch S theretofore under tension to instantly close. This quickly throws a braking current on the motor and brings it promptly to rest. Similar actions takeplace when other positions of stopp ,g are selected by moving the disk B of the dial controller Y.

In case the disk 13' be rotated to the left from the position shown on the drawing, the circuits and the operation will be as described except that the-control circuit will travel through the segment C, thewire 13, the wires 15 and 14, and the windings of the reversing switches U and U causing them to close the motor circuit which has the same course as before only the current is reversed through the armature A, causing it to reverse its direction of rotation. The interlock L, instead of the interlock L prevents the closing of the switch S until the arm G is in the proper position.

I claimi 1. The combination of an electric motor, a switch member driven thereby, a series of fixed contacts cooperating with the switch member, a setting switch having fixed contacts corresponding to the first-named fixed contacts, switches for reversing the motor, contacts on the setting switch for governing the reversing switches, a braking switch for connecting the motor armature in a closed braking circuit, and'a contact'on'. the setting switch for governing the braking switch.

2. Thecombination of an electric motor, reversing-switch mechanisms therefor, a braking switch for including the motor armature in a closed braking circuit, a setting switch having contacts for controlling the said switches, a switch driven by said motor, and contacts connected to the setting switch contacts and arranged to maintain a reversing-switch mechanism operative and the braking switch under a closing strain until the motor driven switch reaches a position corresponding to the stopping position of the setting switch. 1

3. The combination of an electric motor, a switch member driven thereby, a series of fixed contacts cooperating with the switch member, a setting switch having fixed con-, tacts corresponding to the first-named fixed contacts, a braking switch for connecting the motor armature in a closedbraking circuit, and a contact on the setting switch for governing'the braking switch.

4. The combination of an electric motor, reversing switch mechanism therefor, 21 braking switchmechanism, a setting switch -having one'set'offcontacts connected to the =said switch mechanism, and another set of 1 contacts cooperating with the first set 'of contacts, a set of fixed contacts connected to the second set of contacts ofthe settingv tact being long enough to engage one fixed contact before leaving another but short enough to engage one fixed contact without engaging the adjacent contact at eithenside thereof.

, Signed at Cleveland, Ohio, this 18th da of January, A. D. 1909.

FREDERICK R. FISHBACK.

Witnesses: A

H. M. DIEMER W. A. TENWINKLE.

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