US2675507A

US2675507A - Machine control device

Info

Publication number: US2675507A
Application number: US159767A
Authority: US
Inventors: Willard L Geiger
Original assignee: TRONICS Inc
Current assignee: TRONICS Inc
Priority date: 1950-05-03
Filing date: 1950-05-03
Publication date: 1954-04-13
Anticipated expiration: 1971-04-13

Description

April 13 1954 w. GEIGER MACHINE CONTROL DEVICE Filed May 3. 1950 www SSLS f T R. f vw QQ N Mmmm, n mllvw N ,v FM. E e n W6 w l /m C A Q, d 3m w m j -I C@ w N C C QW LJN NQ w: C@ uff xi l QN mh f 1 C Sm f C@ @C C l@ I mm wmwmm ht. Y; X QQ NQ l||. .f N www Q @C NQ( W C QM 6N .C CTS Q Patented Apr. 13, 1954 STATES PATENT OFFICE Machine; CONTROL DEVICE Willard L: Geigenlfonawanda, N.,Y., assignor to -Tronics, Inc., Buffalo, N. Y.

`'--AimicatioblrMaye; 1950,'seria1No`; 159,767A

s claims. (el. 31a-,151)

'Thepresentlinvjntion' rela-testo electrical control "SyStmsj-frlriachinry' of the blass having af' cyfclrofV movementsg for "example-power Ypresses niwhich"fahead reciprocatesin one Adirection from'ia 4"startingfpositionto perform Va-piressing operation on work pieces-and is then reciprocated the other dir'i'cijionto the starting position t complete-:the ycle; f i

VIM-Prior'systems pfffthisv'classhave included provision Afor co ritirnirlziiis.5 Slfl'gl'e-cy`cle-,` and .inching pr esofgoperationln 'such prior systems it h beenjeustorjiiaryv providesynchronization ci'i'rctlyl-fromthe `rinap ine toy meansofk a plur` kityf of -canr op'erait ft'AsWitche's'and/or reif .cuit has consisted `of heavyll 1`0- vbltfaltematmg current elements; In. accordancewith the-present invention a control for suol-1 machines` isprovided? uwherein :only one camk switch -and'- only-lone relay are necessary, part ofthelsynchronizationfunction being-'furnivsh'ed hy a;timevldelaycondenser andwh-erein small; lightfrweightilquick-acting direct. current lements arefusedin. :the 2 circuits; Another 'important -reatiire of-thepresent( invention resides i-nthe'. provision- `oflr anlinching control wherein eachedepressin of the 'inching push-hutten resultsu'injaf den-nite; positive operation of the machine' -forf` 1Jpre= deterrnne'd'f. adjustable ltime, g the elementcffskill outof the thereby ita-kin Y v i inching. operation anda further giving superior resultslo'ver that lo'lvii'ain'a'lzile Lwith Vthefcustom'ary iiiiitime control the "hands of feven the nfiofst liilled operator. lnlaccord with another featureAAof--fthe invention, provisioniis made. lfor introduction'of.aisatety device insuch: a way that thfsafetyf device,functionslappropriately in each phasesofmachinaoperation r' 1 fl fillhei presentiinvention;` has perhaps? Viits "most importantl-:appiicationtolpower: operated presses oi'ltlievertically 'reciprocatory type and will thenefore;he illustrated andrdescribed herein as applied to such a power press, although aszzwll become:iapparentahereinaiterizthe'.. invention is not limitd in applicatirrrto presses. but may be; applied"igenrallyl-:toffmachih'ery .which has a Hence. a Ageneralobject-o `the invention is to provideaniniproved- 'control system for cyclically operated machines to insure that the machines will operate safelyl and efficiently under all conanions of;operai;ici-1fl y ""Anothery object jof theinvention is to provide in al control -systenr- Yfor?cyclically --operating 'maofthetype' employing anielectro-magnetic devic'elt eont'rol-a'cluteh and -brake for the ma- 2 chine, improved control means whereby only .one cam operated switch andl Onerelayare needed for synchronization and llwhereb-y vlight-weigl-it fast operating D. C'. elements are used.

Still another object of the invention is to provide a control systema'for a machine yof 'the cycli-I cally operating typeloywhichduring singlecycle operations the machine may be started only after all of the operators"push-buttonsare closed' and will stopunless all of the push-buttons areheld closed for a predetermined partY of theoperat.- ing cycle of the machineand Iwhich will thereafter continue to run tothe end-of the. ycycle after the push-buttons have been Sreleasedand which will automatically stop at-the end ofthe cycle independently of Whether the-:pushebuttons have been relased and which cannot be started to begina cycleunless all of thefpush-buttons have -rst been released-at the end-of the cycle.

Another importantA object of` the invention is toprovide a novel-inching control. wherein each depression of the'inching push-button results .in a positive pulse of machine operation ofadjustable predetermined time length.

Another object ofthe invention is to provide afcontrol means asi aforesaid which incorporates both hand `and foot operated switches which may beselectively employed `by the machine op? erator to obtain anydesired control.eiectlLA-x` Another object of 1thelinvention is..to. provide in va deviceof the character aforesaid 'means to connect: any eXisting externall additionall safety device to the mechanism ofthe invention without requiring eitherrmechanism` to be 4rewired for operation oftthe protection providingiunit atzall times Awhen necessaryf" i 1 i A still further object of the invention is to provide aprotection feature wherein ythe Iprotection device-is effective at all times when the machine is in continuous operation and;Wherein.;t1ie:pro tection` device is effective only duringthe down,- Ward stroke when the machine is in a singlecycle operation and wherein ,theprotection deizicev is lay-passed during inching operations so thateach phase of operation.. is attended 'oy vspecifically adapted protection conditions. .f f

Other objects and advantages of the invention will appear from the specification hereinafter.

v'In the drawing herewith Fig. 1 is ,a schematic View `illustrating a preferred control system for a machine embodying myY invention; and

Fig. 2 is a diagrammatic view illustratingthe timed sequence of operation of the contactsvof the limit switch of Fig. 1. i r f 3 trolled by the system of the invention may be of the type, for example, in which a driving clutch and brake are alternately engaged to start and stop the press, or it may be of the type in which the brake is continuously engaged; in either case the driving clutch is usually engaged by a pneumatic or hydraulic actuator which is under the control of a solenoid valve such as is diagram- ,matically illustrated at with its coil 30. According to one feature of the invention, synchronization of the control with the machine is effected in part through a limit switch 44 which .is operated by a cam 50 carried by the machine drive shaft 52. The control system of my invention in the illustrated preferred form incorporates a selenium or other suitable rectifier 60 together with a current limiting resistor 62 and a filter condenser 64 to provide a direct current power supply for the system which includes` a plurality of operators run push-buttons 65-65 and an operators pedal 66, a hand-foot selector switch 68, a run timing condenser 10, a condenser bleeder resistor 12, a jog push-button 14, a jog condenser 16, a jog condenser bleeder 16, a continuous push-button 80, a stop push-button 82, a rotary selector switch 84, and a control relay 86, and which is subject to certain overcontrol effects of protection device 88, as will hereinafter be more fully explained.

The rotary selector switch 64 is provided to predetermine whether the press is to run a single cycle and then stop; or whether it is to run continuously, cycle after cycle, after being once started until stopped; or whether it is to be inched ahead by small predetermined increments of movement such as are necessary when the dies on the heads of the machine are being adjusted; and the foregoing positions of the selector switch are such that the

cam elements

90, 92, 94 thereof are correspondingly brought into operation against their respective switch elements, the selector being illustrated in the inch position.

Assuming that it is desired to operate the machine continuously, cycle after cycle without stopping, the rotary selector switch 84 is moved to continuous position whereby the cam element 94 closes its corresponding switch 96. If the "continuous push-button 80 is then depressed, a circuit is established yfrom one alternating current power line LI, through the rectifier 60, by wires 98, |00, |02, and |04, through the push-button 80 and the normally closed stop button 62, through the closed switch 96 and the resistor |06, by wire |08 to the coil ||0 of the relay 86 and thence by wire ||2 to the other` AC line wire L2. This causesthe relay 86 to close whereupon the contact 86A thereof forms a maintaining circuit by wires ||4 and ||6 across the contacts of push-button 80. Assuming that the protection device 88 is energized and its contactor ||8 is thus closed, the closing of the relay 86 establishes another circuit from line LI, by wire |20, through solenoid 30, through contactors I8 and 86C, by wire |22 to the line L2, thus energizing the coil and operating the valve 20 so as to start the press. Since the control circuit has been sealed in through the contact 86A, thelp'ress will continue to run until the circuit of the Yrelay 86 is broken by operation of the stop button62, provided that the ccntactor I I8 of the protection device 88 does not open.-

If it is desired to run the machine `by single cycles, the selector switch 84 is rotated so .that the cam element 90 depresses a pair of ganged switches |24| 26. As will be seen in Fig. 2, if the 4 machine is in position to start a cycle, the cam switch 44 will be depressed so that its contact 44A is open and its contact 44B is closed.

A choice of run operating switches is provided so that the machine may be either hand or foot controlled. For hand operation a plurality of push-buttons 65-65 are provided so as to fully occupy the hands of the operator or operators, and these push-buttons are series wired so that they must be operated concurrently to close either circuit through them. The switch 68 may be thrown to either hand or foot position, it being illustrated and described in the latter so as to put the foot pedal 66 into the circuit. Then with pedal 66 in its normal position with the contact 66A thereof closed, a condenser charging circuit is established from line Ll through the rectier 60 by wires 98, |00, |20, and |30, through a resistor |32, through the closed contact 44B, by wire |34, through the closed contact 66A and the hand-foot switch 60, by wire |36, through the switch |24, by wire |30 to the adjustable condenser 10 which in turn is connected to the line L2 by wire |40. This `circuit quickly charges the condenser 10 to the voltage provided by the rectifier 60. Then, if the-pedal 66 is depressed so as to open the contact 66A and to close the contact 66B thereof, the foregoing charging circuit will be broken and a condenser discharging circuit will be established from the condenser 10 by wire |38, through the switch |24, by wire |36, through the switch 68, through the now closed Contact 66B, by wire |42 and wire |44, through the resistor |06 and the relay coil ||0, by wire ||2, the line L2, and the wire |40 back to the condenser 10. This will close the relay 86 so as to establish a press operating circuit through the contact 86C thereof as before. When the press has traveled degrees, the limit switch 44 will be released thereby closing its contact 44A and opening its contact 44B.

When the contact 44A closes, a circuit will be established from the line L| by wire |20 through the solenoid 30, by wire |46, through the contact 44A, by wire |48, through the switch |26, by wire |50 to the line L2. This circuit will continue to energize the solenoid 30 so as to 'continue to operate the press so long as the contact 44A is closed regardless of whether the relay 86 'and the device 88 are energized. Thus, when the press is being operated under the run phase of control, the pedal 66 may be released at any time after the press has traveled 1'20 degrees without halting operation thereof. Referring to Fig. 2, it is seen that contact 44B is closed during therst 120 degrees of press operation and that contact 44A is closed during the remaining 240 degrees, there being a slight overlap becausel the limit switch 44 is of a make-before-break type. Thus, the condenser 10 can be charged through the contact 44B only during the downward stroke of the press.

The capacity of the condenser 10 is adjusted relative to the current drain of the coil |0 of the relay 86 so that the condenser will furnishsulcient power to continue to energize the relay 06 during the entire 120 degrees downward stroke of the press during which the press is dependenty up-v on the contact 86C for its operation, but the capacity of the condenser 10 is adjusted to be less than the amount which would be necessaryto energize the relay 86 for the remaining 240 degrecs of operation. The condenser 'l0 may be rendered adjustable in any suitable manner, as for example it may be made up of a number of vcorresponding switch |52.

'the jog push-button 14, by wire i condensers 'in parallel with 'provision to disconf neet one or more from the circuit to decrease the total capacity. Thus, if the pedal 66 is depressed `and held, the press will start to operate as a result of the closing of the relay 86, and there will be a sufficient charge in the condenser so that before it is depleted to the point where the relay 86 Will drop out the press will have traveled 120 degrees andthe contact 44A will have closed so as to continue the cycle to completion. During the rst 120 degrees the press may be started and Vstopped at will by operation of the pedal 66, each release thereof re-establishing a full charge on `the condenser l0, However, even if the condenser 'l0 is recharged just before the press reaches 120 degrees, continued holding of the pedal 66will not cause the press to repeat because `the charge on the condenser '10 will have been fully dissipated in the remaining 240 degrees of operation. If the pedal 66 were released during the return portion Aorf-the -cycle while a substantial charge still` remained in condenser 10, it might be possible to redepress pedal 66 just before the end of the cycle and cause the press to repeat were it not for the resistor 'l2 which is adjusted to bleed the condenser 10 during the return stroke of the press even though the push-button or foot pedal isv released. Thus the condenser 70 Will be bled of its charge during the return portion of the run cycle in any event so that a new cycle cannot be initiated until the condenser 'I0 is recharged through

contacts

44B and 66A. It Will be observed that Vin the run phase of control the protective de- .Vice 88 is effective only during the downward stroke of the press,

it being lay-passed through the contact 44A during the upward stroke for reasons which will appear hereinafter.

If it is desired to inch or jog the press by small increments, as, for example, when setting up dies or jigs, the selector switch 84 is rotated so that the cam element 92 thereof depresses the A fjog condenser charging circuit is then established from the line L| through the rectifier 6|), by wires 98, |00, and |54, through the normally closed contact 14A of 56, through the closed switch |52, by wire |58 to the jog timing condenser '16 and thence by wire |60 to the other line L2. If the jog push-button I4 is then depressed, the foregoing charging circuit will be broken by the opening of the contact 14A and a discharging circuit will be established from the condenser 16, by wire |58, through the switch |52, by wire |56, through the now closed contact v141B, by wires |62 and |44, through resistor |06,

by wire |08, through the coil ||0 of the relay 86 and by wires 2, L2, and |60, back to the other side of the condenser 16, thus quickly picking up relay 86 by the full power of the condenser 'I6 so as to close the contact 86C and initiate operation of the press. When the relay 86 has completely closed the contact 86B establishes a condenser bleeder circuit across the condenser 'I6 by wires |58 and |64, through the contactar 86B, by

vwire |66, through adjustable resistor 78 and the xed resistor 'I9 and by wires |68, L2, and |60. This bleeder circuit immediately starts to drain the charge from the -condenser 16, and the rate of drain may be predetermined by adjustment of resistor 18 so that the Voltagel across the con.- denser 16 will reach the drop out value of the relay 86 within any desired interval after the closing of the relay 86 so as to terminate the ljog power impulsa It is a special feature and advantage vof this invention that thejog inter- 6 vvar-is:limited to' an adjustablypredetermined maximum so that all the operatorrneeddo is adjust the resistor I8 for the desired jog increment and then press the jog push-button 'I4 and continue to hold it depressed until the jog impulse has been completed, so that no skill or attention on the part of the operator is necessary to prevent unwanted'excess in the jog movement. It vis another important feature of the invention that the relay. 66 is positively picked up with the `full'powerof the. condenser I6 regardless of how short a jog increment is desired, inasmuch as the variable jog terminating function is not brought Vinto the circuit until the relay 86 actually closes'. Inasmuch as novprotection is needed or desired during the jogging operation, the jog'` push-button.'|4 is provided with a third, normally open contact 14C which shunts the contact S of protection device 88 through wires |10 and |12 whenever the push-button is depressed. i `v ThusVthe invention provides a control wherein the `various elements are brought into cooperative relationships such as to individually satisfy the requirements of each phase of machine operation-continuous, run, and jog. For example, theirelay 86 is utilized in all phases of operation, but it is supplied with unique control circuits for each phase and is by-passed by theY contact 44A during part of the run cycle. Further, the protection device is particularly adapted to each phase of operation; for example, it is effective to stop the machine at all times during continuous cycling so that in addition to preventing injury during the down stroke, it will also detect material fouling or the like on the up stroke. On the other hand, during single cycle run operations the machine is always attended so that the danger of material fouling on the up stroke is not present; on the contrary, it is desirable that the operators be free to serve the press during the non-dangerous part of the cycle without the inconvenience resulting from stopping the press due to tripping of the protection device. Thus, when the machine is being operated under run conditions the protection device is effective during only the first degrees of the cycle, it being shunted by the Contact 44A during the remainder thereof. Finally, during jog operations there is no danger, and, as a matter of fact, it is necessary that the operator be free to enter between the jaws of the press so thathe can adjust the dies, etc.; therefore, the additional contact 14C is provided on the jog push-button 'I4 to shunt protection device so that the latter will not prevent inching of the machine.

From the foregoing it will be apparent that the invention provides an extraordinarily foolproof, light, and compact control for cyclically operated machines while employing a minimum of moving elements and providing for a maximum of safety and efficiency ofA operation. Although only one form of the invention has been illustrated and described in detail, it will be understood that the invention is notl so limited but may be otherwise embodied within the scope of the appended claims.

What is claimed is:

1.v In a control for a cyclicly operated machine, an operators push-button having a norjmally closedcontact and a normally open con.- tact, a. limit switch with a first contact and a second Contact closable substantially alternately, a

first portion of the cycle of the machine'and to close. said second contact during the remainder of the cycle, a source of electric energy, a condenser, a resistor, a relay having a normally open contact, a condenser charging circuit including said source and said first contact of saidlimit switch and said normally closed contact of said push-button and said condenser in series, a condenser discharging circuit including said condenser and said normally open contact of said pushbutton and the input of said relay in series, a condenser bleeder circuit including said condenser and said normally closed contact of said pushbutton and said resistor in series, and a machine actuating circuit including said contact of said relay in parallel with said second contact of said limit switch.

2. In a control for a cyclicly operated machine, an operators push-button having a nrst contact and a second contact, a limit switch with a first contact and a second contact, a cam adapted to be operable by the machine to actuate the contacts of said limit switch, a condenser, a resistor, a relay, a condenser charging circuit including said rst contact of said limit switch and said rst contact of said push-button and said condenser adapted to be under series control of said first contacts, a condenser discharging circuit including said condenser and said second contact of said push-button and said relay adapted to operate said relay under series control of said second contact of said push button and the discharge current of said condenser, and a condenser bleeder circuit including said condenser and said first contact of said push-button and said resistor adapted to be under series control of said nrst contact of said push button, a machine actuating circuit including a contact of said relay, and a second machine actuating circuit including said second contact of said limit switch.

3. In a control for a cyclicly operated machine, an operators push-button having a normally closed contact and a normally open contact, a limit switch with a rst contact and a second contact arranged to be closable substantially alternately, a cam adapted to be operable by the machine to close said first contact during a first portion of the cycle of the machine and to close said second contact during the remainder of the cycle, a condenser, a relay having a normally open contact, a source of electric energy, a condenser charging circuit including said source and said lfirst contact of said limit switch and said normally closed contact of said push-button and said condenser in series, a condenser discharging circuit including said condenser and said normally open contact of said push-button and the input of said relay in series, and a machine actuating circuit including said contact of said relay in parallel with said second contact of said limit switch.

4. In a control for a cyclicly operated machine, a machine control solenoid, an electro-magnetic contacter having a iirst normally open contact, an overcontrol protection device relay having a normally open load contact and an operating coil, said coil having energizing leads arranged for connection to an external protection device as the sole control of said coil, a source of electric energy, a rst machine actuating circuit comprising said first normally open contact and said normally open load contact and said control solenoid in series across said source, continuous and single cycle and inching control circuit means for corresponding types of machine operation,` each said control circuit means being adapted to control said electromagnetic contactor, a selector switch i or selectively bringing said control circuit means into control relation with said electro-magnetic contacter, said inching control circuit means comprising means for limiting the extent of the movement of the machine to a small increment during each operation thereof, said inching control circuit means comprising a shunt contact arranged to be closed by and during operation thereof, and a second machine actuating circuit comprising said shunt contact in series with said solenoid and in series with said first normally open contact and in parallel with said normally open load contact across said source, whereby said machine may be actuated by said solenoid subject to energization of said protection device relay and may be actuated :by said solenoid independently of said protection device relay but subject to closure of said shunt contact, according to the position of said selector switch.

5. In a control for a cyclicly operated machine, a machine control solenoid, an electro-magnetic contacter having a iirst normally open contact, an overcontrol protection device relay device having a normally open load circuit means and an input, said input having control leads arranged for connection to an external protection device as the sole control of said input, a source of electric energy, a first machine actuating circuit comprising said first normally open contact and said load circuit means and said control solenoid in series across said source, a plurality of control circuit means for different types of machine operation each adapted to control said electro-magnetic contacter, a selector switch for selectively bringing said control circuit means into control relation with said electro-magnetic contacter, at least one of said control circuit means comprising a shunt contact arranged to be closed yby and during operation of said machine by said one control circuit means, and a second machine actuating circuit comprising said shunt contact in series with said solenoid and in parallel with said load circuit means across said source whereby said machine may be actuated by said solenoid subject to energization of said protection device relay device and may be actuated by said solenoid independently of said protection device relay device but subject to closure of said shunt contact, according to the position of said selector switch.

6. In a control for a cyclicly operated machine, an operators control device having a iirst switch means and a second switch means, a limit switch device with a rst switch means and a second switch means, said limit switch device being adapted and arranged to ibe operable by the cyclic movement of the machine to actuate the switch means of said limit switch device, a condenser, a resistor, a relay having an input and an output, a source of electric energy, a condenser charging circuit including said source and said rst switch means of said limit switch device and said first switch means of said control device and said condenser adapted to `be under series control of both said first switch means, a condenser discharging circuit including said condenser and said second switch means of said control device and said input of said relay adapted to operate said relay under series control of said second switch means of said control device and the discharge current of said condenser, and a condenser bleeder circuit including said condenser and said first switch means of said control device and said resistor adapted to be under series 'control of said first switch means of said control device, a machine actuating circuit 9 including said output of rsaid relay, and a second machine actuating circuit including said second switch means of said limit switch device.

7. In a control for a cyclicly operated ma chine, an operators control device having a first switch means and a second switch means, a limit switch device with a iirst switch means and a second switch means, said limit switch device being adapted and arranged to be operable by the cyclic movement of the machine to actuate the switch means of said limit switch device, a condenser, a relay having an input and an output, a source of electric energy, a condenser charging circuit including said source and said rst switch means of said limit switch device and said first switch means of said control device and said condenser adapted to be under series control of both said first switch means, a condenser discharging circuit including said condenser and said second switch means of said control device and said input of said relay adapted to operate said relay under series control of said second switch means of said control device and the discharge current of said condenser, a machine actuating circuit including said output of said relay, and a second machine actuating circuit including said second switch means of said limit switch device.

8. In a control for a cyclicly operated machine, an operators control device having a rst switch means and a second switch means, a limit switch device with a. switch means, said limit switch device being adapted and arranged to be operable by the cyclic movement of the machine to actuate the switch means of said limit switch device, a condenser, a relay having an input and an output, a source of electric energy, a condenser charging circuit including said source and said switch means of said limit switch device and said iirst switch means of said control device and said condenser adapted to be under series control of said first switch means and said switch means of said limit switch device, a condenser discharging circuit including said condenser and said second switch means of said control device and said input of said relay adapted to operate said relay under series control of said second switch means of said control device and the discharge current of said condenser, and a machine actuating circuit including said output of said relay.

References Cited in the file 0f this patent UNITED STATES PATENTS