US2727227A - Control and signal means for motor driven machines - Google Patents

Description

Dec. 13, 1955 E, Q MEAD 2,727,227

CONTROL AND SIGNAL MEANS FOR MOTOR DRIVEN MACHINES Filed June 25, 1952 2 Sheets-Sheet l L1 L2 a, M 1 i Mia M" 5a LA 1TR\ 14o g SIGNAL 7821 3:. INCH g 56 2x17 TR 6a INEC 8 C 9B IO: SAFE b f LIGHTS `SIGNAL O mams Dec. 13, 1955 E, Q MEAD 2,727,227

CONTROL AND SIGNAL MEANS FOR MOTOR DRIVEN MACHINES Filed June 25, 1952 2 Sheets-Sheet 2 SM lTR SAFE STOP OFF- ON LM ETR INCH SIGNAL ON-l ICR I O O 3 a O O la o o 1J O O \`l4b D D 18/0 n D o o lob Z O O V 5a! O O 9 o o k f, a 14' O O 6I7 kb LZ) Il@ O loa /7 c f5@ Q @"0 \4 O O a O 9 s? CONTROL AND SIGNAL MEANS FOR MOTOR DRIV EN MACHINES Edward Q. Mead, Milwaukee, Wis., assigner to Cutler- Hammer, Inc., Milwaukee, Wis., a corporation of Delaware Application June 25, 1952, Serial No. 295,575

6 Claims. (Cl. 340-267) This invention relates to controllers for motor driven printing presses and other machines, and more particularly to controllers embodying signaling means.

Controllers for large printing presses are commonly required to afford signaling sufficiently in advance of starting whether for inching, threading or running to enable the workmen who may be working on the press to protect themselves. Only a short signal period is necessary and it is often important to avoid needless delay in starting.

The present invention has among its objects to provide a controller affording the protection aforementioned, and at the same time affording other desirable operating characteristics.

Another object is to provide a controller of the atorementioned character not only having improved operat n ing characteristics but having also relative simplicity of construction and of Wiring.

Another object is to provide a controller aifording the aforementioned safe feature and improved operating characteristics as functions of depression of certain of the pushbutton switches now commonly employed in printing press controllers.

Other objects and advantages of the invention will hereinafter appear.

In accordance with the present invention as applied to a printing press drive having a relatively small motor for inching, threading and slow speed running and a relatively large motor for high speed ruiming, it is proposed to equip the controller with the usual control instrumentalities including separate pushbutton switches for inching and running. In accordance with the preferred form of the invention it is proposed to provide means whereby depression of either the inch or run buttons will result in both visual and audible warning signals followed by the respective inching or ruiming operation a predetermined time following such depression. It is proposed to have the signalling terminated at the time that the inching or running operation is commenced. It is intended to automatically provide such characteristics following the above-mentioned depression of the inch or run buttons. lt is further proposed to provide the above-mentioned predetermined time interval by means of certain electromagnetic timing relays. Of course recitation of these specific proposals is not to be regarded as limiting the present invention thereto or as setting forth in full the desirable operating characteristics contemplated.

The novel features which l consider characteristic of my invention are set forth with particular-ity in the ap* pended claims. The invention itself, however, both as to its organization and its method of operation, together with additional objects and advantages thereof, will best be understood from the following description of a specic embodiment when read in connection with the accompanying drawings, in which- Figure l is an across-the-line diagram of the controller;

Fig. 2 is a chart showing vertically aligned each coil and its respective contacts of Fig. 1.

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Similar reference characters indicate corresponding parts throughout the several views of the drawings.

First referring to Fig. 2, it will he observed that the controller has certain switches and a number of relays having contacts as follows:

LM relay having a winding l and a set of three normally open contacts 1a;

SM relay having a winding 2 and a set or" three normally open contacts 2a and normally open auxiliary contacts 2b;

A normally open limit switch 3 and a normally closed limit switch 4, each responsive to operation of either the LM or SM relays;

`ZTR relay having a winding 5 and normally open contacts 5a provided with instantaneous closure and timed opening;

lTR relay having a winding 6 and normally open contacts 6L provided with instantaneous opening and timed closure;

inch relay having a winding 7, normally closed contacts 7L and 7b, and normally open contacts 7c and 7d;

Safe relay having a winding 3 and normally open contacts 8a and normally closed contacts 8";

Signal relay having a winding 9 and normally open contacts 9a and normally closed contacts 9b;

Stop relay having a winding l0 and normally closed contacts lila and two normally open contacts lill and 10;

ON-l relay having a winding lit and normally open contacts 11a;

An otf relay having a winding 12 and normally open con- `tacts 12a;

A lCR relay having a winding 13 and normally open contacts 13a and 13b;

- And an On relay having a winding 14 and normally closed contacts 14a and normally open contacts 14h and 14C.

Referring to Fig. l, the relays LM and SM respectively control energization of a large motor and a small motor (neither being shown) for the purpose of operating the press (also not shown).

As will be understood, the press drive will comprise either D. C. or A. C. motors, whereas it is assumed that the motors are A. C. and of the three phase type, wherefore both switches are shown as of the triple pole type.

The system illustrated comprises in addition to the aforementioned switches and relays a crosshead type controller 26 to be operated by a pilot motor M having an armature a and series field windings f and f1, to be excited selectively to effect reverse operations of the motor and hence reverse operations of the crosshead arm 262' of the controller 26. Use of such a crosshead type of controller for a double motor drive for printing presses whether A. C. or D. C. has been common practice for such a long period that both the motor connections and resistances have been omitted, the crosshead controller being shown only as provided with those connections re- 'quired for the LM and SM switches and the pilot motor.

As will be understood, the crosshead has a positionshown as its extreme left-hand position-in which it enables the SM switch to be energized for inching, whereas the crosshead is movable from such position through the medium of the pilot motor M to other positions first to establish running connections for the small motor and then to start the large motor and to regulate the speed ofl the latter.

The pilot motor M is controllable for shifting the crosshead arm 26a to select the positions through the medium of the aforementioned on and oit relays 14 and 12 which in turn are controllable by on and olf pushbutton switches 15 and 16, shown and so labeled in Fig. l.

Further, referring to Fig. l, the same also shows an inch pushbutton switch 17, a stop pushbutton switch 18, and a run-safe pushbutton switch 19. Fig. l also shows the usual limit switches 3 and 4, operatively associated with switches SM and LM as depictedz in Fig. 2. Limit switch 3 is normally open while limit switch 4 is normally closed, but both are jointly operable by either switch SM or switch LM. The arrangement is such that operation of either of said motor switches closes switch 3 and opens switch 4.

The signaling means shown in Fig. 1 comprises signal lights 20 controlled by a flasher 21 comprising a motor 21a and contacts 21h, and also a bell 22. The flasher and the bell are controlled by contacts 9b and 9"',` respectively, of the signal relay.

To inch the press when the crosshead` a1jm`26a is in the position shown and when. all of theswitches and relays are deenergized, the inch button 17 is depressed.` The operation is very simple and expeditious, but so many circuits are involved that the cycle will be described as follows:

When the inch pushbutton switch 17 is depressed a circuit is completed to the ZTR relay through said button 17, winding 5 and the normally closed contacts 14e and 8b. Energization of winding 5 causes contacts Sa to close, thereby energizing the lTR winding 6 and the signal Winding 9. Said signal winding is energized through a circuit consisting of said contacts 5a, the normally closed inch contacts 7a, the normally closed on contacts 14a, and the normally closed safe contacts 8b. Energization of signal winding 9 affords power connections to the bell 22 by virtue of closure of the normally open con tacts 9a. Such energization also opens the normally closed signal contacts 9b, thereby removing the signal lights 20 from across the line and making such lights dependent upon closure of contacts 21b which, as above mentioned, is controlled by motor 21a. It is believed apparent that Fig. l clearly shows the cam arrangement,

whereby continued energization of motor 218L causes contacts 21b to be alternately closed and opened, thereby affording interruptedenergization of the signal lights 20.

The aforementioned energization of the lTR coil 6 causes contacts 6a to begin timed closure. The mechanism for affording contacts 6a with` timedv closurev is shown in Fig. 2 to consist of a dashpot 6b which is, of course, only, illustrative, it being fully realized that.V there are many forms of timing structures which could beused` for this purpose. When said contact 6EL iinally closes, the inch winding 7 is energized byy the, virtue oa-circuit includingthe inch button17, said contacts 6a, andthe normally. closed safe contacts 8b. Energization ofthe inch winding 7 .causes the normally closedinch contacts 7a and 7b-to open and the normally open-inch contacts` 7dvand 7c to close. Opening of contacts 71 removes power from the signal winding 9, thus causing the. power tofibe.

removed from the bell 22, and. the signal lightsto be continuously energized byv virtue of closure of contacts 9*?.

toclosureof the inchcontacts 7d. Energizationof stop winding closes the normally open contacts 10.Il which together with contacts7", now closed by virtue of fenergizationlof winding7, affords energization of the SM switch through said contacts 7C and 10b, the crosshead arm 2.6,a andrwinding `2. Energization of winding 2 causes tobe deenergized due toreturn to normally open positionof the inch contacts 7. Return `to the normallvclosed position, of'inch contacts 71L causes reenergization ofthe signal winding 9, thereby effecting power connections tothe bell 22'v and intermittent operationy ofthesignal Simultaneous with such deenergization ol` thebell 2,2. isr energizationA of the. stop winding 10, due.

lights 20, caused respectively by closure of, contacts 9 a and opening of contacts 9b. Said visual and audible signaling will continue until the ZTR contacts 5 time open, the ZTR coil 5 having been deenergized by virtue of release of pushbutton 17. If the inch button 17 is depressed before the ZTRk contacts 5@- have timed open and terminated the signaling, the inch coil 7 willV be immediately energized` since the lTR contacts 6al are still closed. Thus a second inching operation will be commenced without the aforementioned time delay. Such operation is very advantageous, in that it enables the operator to effect rapid successive inching operations without` needless signaling and time delays. Should an inching operation be desired after the ZTR contacts 5 have timed open, depression of the inch button 17 will instigate the signaling and delayed inching operation as above explained. This results due to the time interval necessary to, close contacts 6a'. When saidV contacts 5a finally open, all of the windings are deenergized. The stop winding 10 has been deenergizeddue toclosure of the inch contacts 7b which short out powerto said winding 10, thus interruptingthe-maintaining circuitfor said winding-which was'previously afforded by stopcontacts 10C.

Duev to theabove mentioned deenergizationof the SM switch, power connections to the small motor are disconnected, thereby permitting the press to come to rest.

To run the press in its normal manner, theon pushbuttonl switch 15 is depressed and subsequently released when the desired press speed has been obtained. The normal run cycle also will be described fully, itv being assumed that the several switches and relays occupy the respectivepositions illustrated in Fig. l.

Depression of the on pushbutton switch 15 energizes the ON-l relay winding 11 through a circuit.L composed of switch 15 and contacts 14?d and 8b. Energization of winding 11 closes thenorrnally. open ON--l contacts 11a', thereby energizing the ZTR' winding 5. Energization of winding v5 immediately-closes the normally open ZTR contacts 5a, thereby instigating the audible and visual signaling asprecedestheaboveexplained inching operation. inch winding 7 is energized and the signaling operations are terminated by virtue-of opening of contacts71. As above explained, closure of contacts 7d energizes the stop winding 10fand cause contacts 10b to vcl0se;lsaid contacts 10b together with the inching contacts 7c efiect energization of the SMwnding 2, thereby causing the smallmotor to. operate. Energization of winding 2 causes the normally open auxiliary contacts` 2b to close, -therebyenergizing the ON winding 14 through a circuit consisting of switch 15 and contacts 2b and 8b.` Energization of Winding 14 opens contacts 14@ and closes contacts 141? and 14a.

Opening of contacts 142?L affords deenergizationof the ZTR winding 5, thereby permitting-the 2TR contacts.5a to time .open during energization of.winding `14, thus insuring the elimination of signaling followingl normal running of the presses.. also affords deenergization of the ON-l winding 11. Closure of contacts14.c affords continued energizaton of the inch winding 7 after the 1TR.winding 6l has been deenergized by. virtue of the timed opening of said contacts 5a'. Thel limit switch 3, in series-,with the normally open on contacts14b and the field winding]c of the pilot motor M, is now closed due to the aforementioned energization of winding 2. As above noted said limit switch 3 is responsive. to energization of either the SM or LM switches. Suchclosure oflimit switch' 3-together with closure` of contacts 14h affords energization of the field winding f causing the pilot motor M to operate to effect movement olrcrossheadV arm 26a from'itsextreme lefthand position. The aforementioned energizationof winding zf-has causedenergizationrof the: smallmotor, thus causing the presses .to operate slowly..

As soon as the lTR contacts 6a time closed, the

Said opening of contacts 14?' increases in speed until a point 261 is reached, at which point the ICR winding 13 becomes energized by virtue of the circuit completed through limit switch 3, members 26c and 26d of crosshead 26, and contacts 11th. inergization of winding 13 closes the normally open contacts 13a, thereby affording energization of the LM winding 1. Energization of winding 1 closes contact set 1SL thus affording power to the large motor (not shown). The small and large motors are so constructed that when the large motor is energized the small motor is automatically deenergized due to mechanical interlocks therebetween. The presses are thus rotated by virtue of energization of the large motor which increases in speed until the on pushbutton 15 is released or until the crosshead 26lau reaches the eXtreme right hand position.

Should it become desirable to increase the speed of the presses While the crosshead 26a is in an intermediate position, such change in speed can be effected by de` pressing the on switch 15. Such closure of switch 15' reenergizes winding 14 thereby closing contacts 14h and effecting energization of the field winding f of motor M, causing arm 26EL to be moved to the right.

Closure of the off pushbutton switch 16, on the other hand, effects energization of the oft winding 12 which causes contacts 12a to close, thereby effecting energization of field winding f1 and causing arm 26a to move from the right to the left, decreasing the rotational speed of the presses. Release of the off pushbutton switch 16, of course, effects deenergization of said winding 12., opening the contacts 12a and removing power from the pilot motor M.

When it is desired to bring the presses to rest, it is only necessary to momentarily close the stop pushbutton switch 18. Such closure effects deenergization of the stop winding causing contacts 102L to return to closed position, thereby effecting energization of the off winding 12. Deenergization of the stop winding 10 also causes contacts 10b to open the circuit to windings 2 and thus removing power connections from all of the press motors. The presses are thus brought to rest. Energization of the off winding 12 causes closure of contacts 12@ thereby effecting energization of the field winding f1 which causes the pilot motor M to move the crosshead arm 2d into its extreme left hand position. When such extreme left hand position is reached, the ofl:` winding 12 is deenergized by virtue of a conventional limit switch (not shown), in circuit with said off winding 12 and operable by virtue of movement of arm 26a into its extreme left hand position. Thus the controller is completely deenergized.

If it is desired to effect threading of the presses it is merely necessary to maintain the on switch 15 depressed until arm 26EL moves into the position whereby winding 2 is energized through a circuit consisting of limit switch 3, arm 26a, the winding 2, and contacts 10b. At this point the on button 15 can be released to eliect slow threading operation of the presses by virtue of the continued energization of the small motor. From this position the presses may be varied in speed or completely shut down as above explained for the normal run operation.

When at rest the press may be made safe by closing the run-safe switch 19. Such closure energizes winding 8 thereby opening contacts 8b and causing inch switch 17 and run switch 15 to be inoperative. Energization of winding 8 also effects closure of the normally open safe contacts Sia thus affording continuous energization of the safe lights 23. Before the presses can be operated again, the run portion of the run-safe switch 19 must be depressed. This, of course, removes power from the safe lights 23 and closes contacts 8b, thereby setting up the energizing circuit for winding 7 so that subsequent closure of either inch switch 17 or on switch 15 will effect energization of said inch winding 7 as heretofore explained.

It is thus apparent that signaling will be effective before inching, running or threading operations.

Although I have shown and described a specific embodiment of my invention, I am fully aware that many modifications thereof are possible. My invention, therefore, is not to be restricted except insofar as is necessitated by the prior art and by the spirit of the appended claims.

i claim:

1. In a safety controller for an electric motor, in combination, an electric motor, a time delay starting circuit and warning signal means, said circuit comprising a starting switch and first and second electrically energizable timing relays having timed closing and timed opening contacts respectively and starting means for said motor comprising the contacts of said first relay and said starting switch, the contacts of said second relay being in the energizing circuit of said first relay, and said signal means being responsive to actuation of the contacts of both of said timing relays.

2. in an electric motor controller, in combination, a starting switch, a first timing switch operative after a predetermined interval following energization thereof to actuate its contacts, a second timing switch operative after a predetermined interval following deenergization thereof to actuate its contacts, an electric motor, means including said starting switch and contacts of said first timing switch for energizing the motor, an energizing circuit for said first timing switch comprising contacts of the second timing switch, and an energizing circuit for the second timing switch comprising said starting switch 3. In a motor controller for inching operation of an electric motor, energizing means for the motor comprisimI an inching switch and means to render said energizing means ineffective for a predetermined time following actuation of said inching switch, and means to maintain said energizing means effective for a predetermined perind following cessation of an inching operation of the motor.

4. in a controller for safely inching an electric motor, in combination, an electric motor, electro-responsive means to energize the motor, energizing means for said electro-responsive means comprising an inching switch and means responsive to actuation of the inching switch to prevent energization of the electro-responsive means for a predetermined period following actuation of the inching switch and to permit energization of the electroresponsive means during a predetermined interval foln lowing actuation of said inching switch whereby successive inching operations may be commenced without time delay only if commenced within a predetermined interval following a previous inching operation.

5. The combination defined in claim 4t including safety signalling means and means including said inching switch to initiate signalling thereby, and means to terminate said signalling during periods in which said motor is inched.

6. In a safety controller for an electric motor, in combination, an electric motor, an inching switch for affecting inching operation of the motor, means responsive to actuation of the inching switch to prevent inching operation of the motor during a given interval following actuation of the inching switch, and means to permit inching operation of the motor in response to actuation of the inching switch during a given period following an actuation of the inching switch, whereby successive inching operation may be commenced without delay only if commenced within a given period following a previous inching operation.

References Cited in the file of this patent UNITED STATES PATENTS 1,588,087 Billingsley June 8, 1926 1,709,517 Billingsley Apr. 16, 1929 1,790,681 Smith Feb. 3, 1931 2,241,589 Feldhausen May 13, 1941

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