US2635200A - Control mechanism - Google Patents

Description

April 14, 1953 w. DE L. BERRY 2,635,200

CONTROL MECHANSM Original Filed Sept. 3, 1946 2 SHEETS--SHEET l April 14, 1953 w. DE L, BERRY 2,635,200

CONTROL MECHANISM Original Filed Sept. 3, 1946 2 SHEETS--SHEET 2 ms. MM p. 455mm/ atroz/41.114,

Patented Apr. 14, 1953 CONTROL MECHANISM WilliamlDe LohrV Berry, Pittsburgh, Pa., assigner to General Motors: Corporation', Detroit, Mich., a corporation of Delaware Original application September 3, 1946, Serial'No.

694,644'. Divided and this application Januaryl 12', 1951*, Serial'N;.205,695

(Cl. S10-93) l2A Claims.

1 This invention relatesto a control system and morespecically to av system fork controlling the operation. oi a motor driven press Welder and is adivision of a co-pending application Serial No. 694,644 filed September 3, 1946, in the names.

oi William De Lohr. Berry, Sterling G. Vigars, and William E, Adamek entitled Control Mechanism. In. the operation of that. class of heavy machinery such as punch presses and pressweld erswhichperforma pressing, stamping or clamping. operationa heavy ram isz provided.L which is.

moved with respect to a stationary platten. Conventional driving meansA for the ram in these machines has: heretofore been in the form of a' large heavy flywheel thatY is driven bythe motor and suddenlyv clutched to the driving means for the, ram by means of a. jaw clutch, This causes high initial stresses in the parts and attendant noise. and vibration. It also makes the service problem a major one. In order to eliminate the problems attendant such construction and provide a smooth rapid acceleration of the ram it is proposed to utilize'an electromagnetic clutch between thev flywheel and the ram drive so' that there will be no direct mechanical connection. between parts which willbe driven by a magnetic flux interlinliage.A

Itis therefore an object of my invention to providey a control system for an electromagnetic.-

drivefor-heavy machines.

It is a` further object of my: invention to provide a control system for an electromagnetic clutch and brake'iorvheavy machines.

It is a still further object of my invention to provide a control system for an electromagnetic drive forl press welding machines.

.With these and other objects in view which will become apparent as the specication proceeds, my invention will be best understood by reference to the following specication and claimsv and the illustrations in the accompanying drawings, in which.:v

Figures 1 and 1A form parts of a complete cir,- cuit diagram of. the control system of my inven tion. and Figure 2 is a diagrammatic showing of cam.- switch operation associated therewith.

Figure 1l and Figure 1A are combined by connecting the four lines at the bottom of Figure l als indicated by arrowsl with similar four lines at the top of Figure-1A.

Figure 2 is a diagrammatic showing of the phased mechanical operation of the cam operated switches;

AFigure 3- is a schematic diagram off the drive.4

between the motor and movable machine part.

` to rotate in the opposite Inasrnnch as each relay coil when energized actuates a plurality of switch contacts either to open or close the same, it would be confusing to, show on the drawings the connections between each relay actuatingy coil and its associated contacts and so for purposes of this application the relay coils will be, designated by letters, such for example. as A and the contacts actuated thereby by the same letters plus identifying numerals such as AI and1A2 etc., depending upon the number of contacts. actuated thereby.

Referring now morespeccallyto the circuit, there is shownl a threephase power supply, lines 2, ll and Si connected to a main control switch 8, three input conductors, lines I, I2 and i4 being connected to the opposite side of the switch. Line I terminates in a pair of parallel conductors I6 and iiwhich are in turn connected to one termi nal 20 of the three phase driving motor 22. In each ci the lines I6 and I8 there is a switch FI and RI respectively. Lines I2 and I4 are crossconnected by lines 24 and 2E, which connections have serially incorporated therein switches F2 and F3 respectively. serially interposed in lines I2 and Iware switches R2 and R3, line I2 being connected' to terminal 2S and line I4 to terminal 30 of motor 22. Connected across lines I2 and I4 by lines 36 and 38 is primary 32 of transformer 34; This-is a power transformer which provides the` necessary energy for the various actuating relays. Lines 36 and 38 are connected ahead of the various. switches F2, F3, R2, R3 so that the transformerwill be energized as soon as the main switch 8 is closed. Power line 4D is connected to line I2 between. these switches and the motor 22 and the associated power line d2 is connected to line I4 in. like manner. These latter lines therefore are not energized unless either the series F switches or the series R switches are energized. It will thus be obvious that as soon as the main power switch is closedthe motor will be energize to run in one direction by the closure of the F seriesswitches', or'forward, or it may be energized direction or reverse by the closure; of. the R series switches.

Secondary 44 of transformer 34 has line 4t connected to one terminal and 48 connected to the opposite to providelower voltage power leads than lines 40-42, tov provide current for the various relays and further switches. Directly connected acrossbetween these lines is an indicator lamp which indicates to the operator whether or not the.y power supply is, energized. Directly connected in series relation between lines 46 and 48 are a series of control switches and energizing coils for controlling the forward and reverse contacts F and R which include a switch 52, a stop switch &3, a manually closed switch 5S which the operator closes to energize the motor 22 in a forward direction, a normally closed contact R4, relay coil F and. a normally closed contact 53 which is thermally controlled by motor temperature and is operated by coils 69 in the motor line. Thus if the temperature of the motor exceeds a certain value this safety switch 58 will open. It will thus be obvious that switches 52, 54, Ril and 53 under normal conditions would be closed and therefore when the operator depresses switch 5B, relay coil F willV be energized to close the F series contacts and energize the motor 22 to rotate in a forward direction. In shunt around the switch 55 is a normally open contact Fd which is closed upon the energization of the F coil to maintain coil F energized but permit release of switch 56.

In parallel to that portion of the circuit just described including switch 55, contact R4 and relay coil Fis a second circuit for controlling the reverse rotation coil R which has in series with it a contact F5 which is closed when relay coil F is de-energized, a reverse switch 6l operated by the operator and a similar hold in shunt switch R5 which by-passes manual switch 6 l. Through this circuit relay R can be energized by the manual closure of switch which in turn actuates all the R contacts and causes the motor to run in a reverse direction. .At this point it will be obvious that there is provided conventional switching means for a three-phase motor to cause the same to rotate in either one of two desired directions.

This motor is mechanically connected to a flywheel which must be placed in spaced driving relation with some means on the shaft of the press so that the same will operate. This is accomplished through. magnetic flux clutching means between a drum on the press shaft and this iiywheel.

The control for the magnetic clutching means will now be described. Switch 62 is directly connected to line GS for power and is operated or maintained in normally closed position by air pressure in a line (not shown) which provides air to booster cylinders to give the press an initial push to start the same. Thus, under normal conditions this switch would be closed as long as air pressure is provided to the cylinders. A second switch Ell is connected in series with the switch 62 and also is normally closed by air pressure, but in this instance it is by the air pressure provided to the solenoid operated air brake so that the device will not operate unless air is being provided to the brake system. Further in the series connection with the two switches 62 and 64 is a fuse E5. A series of emergency stop buttons 68, lll, l2 and 'M next follow in series relation but placed, of course, in various convenient places around the machine and are normally closed but can be opened to deenergize the whole system if the necessity arises. Y

Connected to the last of the emergency switch buttons is a relay contact Hl which is opened upon deenergization and is controlled by the relay coil I-I which is itself connected across power lines 46 and i8 and has in series therewith only the inch-run switch 16. It will be obvious that when this switch is moved to the position shown or run position the relay coil H will be energized, but when it is moved to itsI upper contact 18 relay coil H will be deenergized and the machine will be capable of inching operation only which will be described. In continued series relation there is connected contact R6 which is closed when the relay coil R is deenergized and opened upon energization of relay coil R, therefore when the motor 22 is running in reverse direction this circuit may not be energized. Line is connected at a point between switch 14 and contact I-Il and extends to contactor CI which is in turn serially connected with contactor SI and relay coil E, the opposite terminal of which is connected to power line 43. Coil E is the relay control coil for the solenoid operated mechanical brake.

Line t2 is connected at a point between contactors I-Il and R3 and extends to normally closed contactor LSB which is operated by one of a series of synchronously driven mechanical cams which appear in Fig. 2 and whose relationship is adjustable and will be later described in more detail. Contactor LSS is in turn serially connected with contactor L53 and contactor E3 which is opened upon deenergization of coil E and closed upon energization thereof. Connected to line 8B is a normally closed contactor H2 which is opened whenever relay I-I is energized, which under all normal conditions is when the switch l is in run position. vIn series with contactor H2 is a manually operated switch 8d which is the inch operation switch. In other words, when switch 16 is moved to contact point 18, the operator may then inch the machine along by closing switch 8 and opening it when the machine has proceeded to the desired point. Continuing in serial relation to switches H2 and 84 is switch Ll which is controlled by the relay coil L which in turn is directly connected across the power lines 56 and 48 and has in series therewith only a time delay operated switch Se. This is controlled by an electronic thermal relay 83 in circuit with the power tubes 9i! and 92 which provide current for the magnetic brake and clutch and this prevents the operation of the whole circuit until the tubes have had an opportunity to heat up.

Continuing in the series relation with the main control line are a series of what is known as run buttons or manually operated switches 94, the number depending upon the number of operators which the machine is to have, two buttons being provided per operator. These switches are normally biased to upper position as shown and when in that position close the circuit through relay coil A to power line 48. When, however, they are in depressed position they tend to complete a circuit through relay coil B. In series relation, however, to the circuit for relay coil B there is a second contactor L2 operated by coil L which maintains the switch L2 closed during the running period of the machine. Also in series relation to coil B is a contactor Al which is controlled by relay coil A and is closed when this coil is energized. To the left of the series of switches operated by the run buttons in this circuit is a switch contactor Ml which is closed upon deenergization but opens upon energization of the relay coil lVI which is the weld cycle initiating relay the intent being to maintain this circuit open when the welding control is dominating and actually performing welds so that the press motor may not be moved at this time.

A conductive line 56 is connected between switches R6 and 94 and extends to a cam operated switch LS2, the opposite side of which is connected to line 98, which in turn extends to an intermediate point between switches Bl and B2. In

shunt relation around the cam operated switch LS2-` isa second cam` operated' switch LS1. Also connected to line. 96 is a contacter N| whichv is controlled by relay coilN andcloses upon energi zation thereof. In series with thisswitch is a pressure actuated switch |06. which is maintained closed byv pressure in the welding gun return line and opens' upon the release thereof. The; opposite.y side; oi the pressure switch is connected through linev i with a pointv intermediate switches A| and L2. Thev two lines just to. the

left of coils C and D which are shown byarrows` ing circuit for relay coil A is provided around the` run buttons194 through conductive'line |04 which has in series relationv three contactors LSI, LSG and A2. under normal springv biasand the relay E isenergized to remove the braking pressure by closure oi two contacts El and E2k which are in series with the brake coil T. The three elements being in series across the lines 45 and d3.

TheV relay coil M is the welding cycle-initiating relay and when this coil is energized the welding machine proceeds through its normal cycleA of welding, the press during'this timeremaining in stationary clamped position. Serially connected with the relayv coil M are the following switch contactors LSE, H5, E4, P2, open when press is not in motion and closed when press is in motion and N2. Connected at an intermediate point between switches H5 and E4 in this series connection is a line |06 which extends to` a control circuit from the Welder indicated bythe two downwardly directed arrow tipped'lines shunted bya switch |08 and thence to the relay coil N. This switch |08` is a limiting switch which is operated by the last contact of the welder timer. In shunt around this Welder controlled switch is a holding contacter N3. InV series with the relay'coil P between lines 46 and 48 is a controlling` switch I0 which is opel`M ated by the speed ofthe member driving the platen and is closed at low speeds and opened at higher ones, such for example asy those above 40 RLP; M.

The power transformer H2 whichv supplies the;

power'for the magneticclutch and brake has its primary H4 connected across lines 40 and 42 of the power supply and has in series'therewith two control contactors D2v and C2 and in shunt relation around each of these contactors are further switch contactors KI and J l' respectively: The secondary ||6 of this transformer is center tapped and connected to line H8. One of the outside terminals is connected through line |20 with a rectifier tube 00 the oppositesecondary terminal is connected through line |22v to a secs SupplyingY the filament. power for these rectierV tubes is a` transformer:

ond rectifier tube 92.

|24 whose primary |26 is connected between lines 40A and' 42 and whose secondary |28 has its two outside terminals connected to lines |30 and |32 which extend to the iilamentv circuits of tubes 90, 92 and 88. Secondary |28 is also center tappe'dandli'ne |34 connected thereto.

The mechanical solenoid brake isset then closed andV H8. and has in seriesrelation thereto coil S' which is provided with some time delay means. switch contactor D3 and C3, on one side and a pair of torquelimiting resistors |38 and switch contactors C4 and D4 on the oppositeside. The two torque limiting; resistors |38Y are. by-passed by a shuntV circuit which include switch contactorsA H5 and H4. on theother hand shown at |40 is also connectedv between lines |34 and ||8 and has in series relation therewith on one side contactor J2 and K2 and on the oppositev side K3 and J3.

FigureV 2. diagrammatically shows the phased mechanical operation of the various, cam operated switches, the. shaded portions indicating the time periods inV acomplete cycle of rotation duringA which the switch actuated thereby is closedV and the unshaded or clearV portions that period,

turned to its lowermost position. The diagrams as will be noted are numbered from 1 tov 9 and the switches in the circuit diagrams of Figs. 1

and` 1A have been identified as LSI. 2 or 3 asf operated by cams 2 or 3 of'Fig; 2.

In Figure 3 the motor 22 is shown provided with apulley 23 driving a rotatable ywheel 25 through a belt 21. The ux generating coil |36 is carried by the flywheel. Rotatably mounted within the, ilywheel is. a spider 29 made of magnetizable material` which is an integral partof a shaft section, 29'. A crank 3| isrigidly connected to the outer end of the shaft section and a link 33 is pivotally connected to the crank end and to a movable part 35 of a machine or press which it is desired to drive or move. A friction brake 31 is spring biased to engage the shaft to prevent its rotation by spring 39 and may be movedy away from braking position by solenoid E. The flux brake coil |40 is supported on a stationary drum 4| within the spider. Thus, with the flywheel continuously rotating when coil |36 is energized', the spider will be driven thereby through theilux linkage and when the coil |36 is. deenergized and coil |40 energized the spider will have` a braking action applied due. to the.

stationary iiux eld. The friction brake is operated to remove the braking action by energization of coil E in proper further described.

The operation of the device will now be` explained in detail. Assuming that the machine is de-energized and in a position of rest, which under normal circumstances would be when the platten is in lowered position ready for the insertion of a part to be welded between the upper andv lower electrodes, the switches all being shown, either open or closed in the position when itsl operating coil is `de-energiaed. Switch. 8 is which appliespower to transformer 34. The power circuit. to the driving motor 22 may be completed by closing' of either switch 56 or 6| as thecase may be depending upon whether the operator desires the motor to run in one direction or the other.

Let us assume that it is desired to energize the motor sot-hat it will run in a forward direction. the. operator then closes switch 56 which compl'etes anobvious circuit through coil F since all The dynamic, brake. coil,

timed relation as will be normally closed by either safety switches or interlock switches. The energization of coil F therefore causes the F contacts in the power line to close and the motor 22 will rotate in the for- Ward direction.

Transformer H2 and transformer I2@ are now energized and until the tubes 90 and 92 have heated a predetermined length of time, none of the remainder of the control circuits may be energized. This is due to the fact that electronic thermal switch 88 will not permit the closure of time delay switch contacts 86.

Since, however, the motor is not clutched to the ram drive no movement of the latter will be aiected. In order to move the ram up into welding position the clutch must be energized. After a suiiicient time period has passed to cause the thermionic time delay means t3 to conduct, it closes switch 86 which in turn energizes relay coil L. Assuming further that it is desired to run rather than inch the press, switch 'i8 is moved to its lower position completing the circuit through relay coil H and that is therefore also energized.

This completes a circuit through relay coil A as follows: Power line et, normally closed switches 32,65, S8, 1B, 12, ljswitch HI, switch R6 which is normally closed when relay coil R is (ie-energized, a series of switches S4, coil A to power line t8. As soon as this circuit is completed, a holding circuit for relay coil A is provided through line IGA, switches LSI, LS and contactor A2 'which is now closed. Referring momentarily to Fig. 2 it will be seen that cam controlled? switches I and l are closed at this time since the shaded portion of these diagrams begins at the upper or zero position of rotation. Relay coil A being energized, AI is now closed, switch L2 has previously been closed as soon as the time delay contacts are closed as previously described, and switch MI is closed inasmuch as relay coil M is de-energized. As soon therefore as all the run buttons S4 are depressed by the operators, relay coil B will be energized through an obvious circuit which closes switches BI and B2 thus completing a circuit through relay coils C and D. The reason for these two coils being connected in parallel and operated simultaneously is strictly for safety reasons. Thus, if contacts operated by one freeze in, the other will still operate the circuit normally since the contacts operated by the two are always in series and the device will not assume any abnormal operation.

The energization of these two coils C and Dv opens contacter DI and closes contactors CIy C2, D2, C3, D3, C, Yand De to complete the power circuit to the clutch coil 36 energizing the same. This magnetically locks the motor to the press drive and the ram begins to ascend since the mechanical brake is also released by the energization of C and E. If the clutch does not become energized, through a tube or brush failure, the series relay S does not pick up and consequently the Si contact in series with relay E does not allow the spring set magnetic brake to release. However,` if current ows through the S relay the magnetic brake will release simultaneously with the closing of the contacts D3 and C3, C and D4 and the press will operate through approximately 155 oi rotation on the depression of buttons 94, at which time cam number 2 operating the LS2 switches will close which by-passes the run buttons 94 which may then be released and the cam LSZ controls the rotation, as shown by theshaded portion in the middle of cam 2 on Fig. 2.-

During the time the cam' 2 takes over cam I allows its contacts LSI to open de-energizing relay coil A which provides an anti-repeat operation should the run buttons still be depressed. This permits cam L52 to control the energization periods of coils C and D and release them at a predetermined point slightly less than a When these coils are de-energized the magnetic clutch, of course, immediately ceases to drive. Just as the clutch is released thc dynamic brake is energized by the closing of the LSII contacts in series with the coils J and K, and acts to bring the moving member to rest. As the ram comes to rest LSB opens to set the magnetic brake and hold it. Therefore the dynamic brake stops the load and the mechanical brake holds it.V

As previously described, the coil H energized so that switch H3 will be closed and also coil L has been energized closing contacts L3. Therefore, when cam reaches a predetermined point, LSd will close energizing coils J and K which, referring now to the bottom of Fig. 1A, completes an obvious circuit through the dynamic brake coil Idil. This combined braking action will bring the press t0 a stop between dead center and 10 ahead of this point and is controlled by the setting of the cam' fi. As soon as motion has ceased relay P opens due to the zero speed switch il to de-energize the dynamic brake, the mechanical bralse holding the device stationary.

In order to insure that'the welding is actuated at the proper time it is controlled by the camv switch 5 which is closed only within the desired range. Therefore, the weld initiating relay M is controlled by contact LSE, the zero speed switch relay P and the magnetic brake relay E which, of course, control the operation of switches Erl and P2 in the series circuit, switch H5 being closed as previously described and N2 being normally 'closed upon coil de-energization as well as E4.

The energization of coil M sets the normal welding cycle off and the welding guns are fired. To assure that welding pressure will be maintained on the work throughout the welding cycle, the

- shunt circuit around switch 'I6 is closed by contactor M2 so that even if switch 'iii is accidentally opened the circuit will still be maintained. After the last gun is fired a contact in the timer, switch HB3, energizes relay N which immediately closes contacter N3 and completes an obvious holding circuit around switch I 58 to hold in relay N. This also causes switch N2 to open, de-energizing relay coil M, which completes the welding cycle. The energization of relay N also closes switch NI which by-passes the run buttons and starts the press on the down stroke or last half of the cycle.

This completes aV circuit for the energization of coil B through line s6, switch N i, switch IBI), line m2, switch L2, relay coil B and this re-energization of coil B closes ccntactors BI and B2 to again energize the magnetic clutch coils C and D and in turn the magnetic braise relay E to release that brake.

As previously described, this action clutches the drive motor 22 to the driving means for the press releases the brake and the press begins to descend. After rotation of a few degrees beyond the welding position, cam l' assumes control by the closure of cam operated switch LS? to maintain cnergization of coils C and D, by-passing contactor N I which initiated the movement. The press continues automaticallyv to move downward until the clutch is (ie-energized by the opening of switch LST slightly ahead of its completion of 360, As the clutch releases the dynamic brake and vice versa when 'is released by the zero 4speed switch ||0 which de-'energizes coil P dropping out coils J .and K Vand their associated contacts.

It might be mentioned at this point that there isa second anti-'repeat cam L'S in series with the rst cam LS! to prevent re-energization of ycoil A and vthus the continuation of the press past the '360 cycle. If Vany of the buttons 94 are released during approximately the Viirst 155 of travel, the press will stop by action of the dynamic and mechanical brakes, but if 155 is past, cam L52 takes over and the press will go through its operation. This operation of pressing the buttons of course, is repeated each time it is desired to operate the press Welder.

Assuming now that it is desired to inch the press rather than to drive the same through a full cycle, switch 16 is placed on contact 'It for operating position. The press rotation is then directly under the entire control of the manually operated inch button 84 and whenever it is depressed an obvious circuit through relay coils C land D will be completed to energize the clutch coil |36 and the press will be driven. However, in this case coil H is not energized and `the bypass around limiting resistors |38 remains open and the resistors are placed in series with the magnetic clutch |36 to cut down Jche current now therethrough to `a smaller amount to reduce the ilux so that the driving force will be less. Whenever the vinch button is released the brakes will be immediately set. The welding sequence during inching operation will not function since lthe relay M cannot be venergized due to the fact that the contactor H remains open. The welding guns however can be actuated manually by the closing of a selector switch on the weld timer which by-passes a switch operated by the vcoil M (not shown).

If it is desired to operate the motor in the reverse direction the switch 6| instead of switch 56 is depressed and the motor will be rotated in that direction. As soon as switch El is pressed to energize coil R, hold in'switch R5 will be closed to maintain the motor operating in this direction. This action also causes switch R5 to open, since this is a switch which is normally closed. This opens the circuit for the run buttons 94 and Vmakes them inoperative. The magnetic clutch and solenoid brake can now only be actuated by the inch switch 84, the clutch being energized vand the brake released. when switch 84 is closed l the same is released, since it controls the energization of coils C and D.

I claim:

1. In a control system for a press, a source vof alternating current power, a motor connectible to said power, rotatable means for driving said press, magnetic hun clutch means between the motor and the'rotatable ydriving means, energiaing coils mounted in the clutch means, dynamic flux brake means associated with the rotatable means to stop the same, a second series of energizing coils for the brake means, rectiiying means' connected to said source oi power, means for connectingsaid two series of coils across the rectifier outputV and resistance means automati- 10 cally insertable in series with the coils for the clutch to vary the'power thereof.

2. In control means for a press having a movable ram, operating means for said ram, magnetix flux clutch means mounted between the operating means and the ram to drive the latter only through a magnetic held coupling, inductive means in said magnetic iiux clutch for providing said field, a source of power, conductive means connecting said source with the inductive means for the clutch, a solenoid friction brake'mounted to bear against the operating means, and relay actuating means for controlling said solenoid brake connected in series with the inductive means for the clutch so that the brake is released when the clutch is energized.

3. In control means for a press having a movable ram, operating means for said ram, magnetic flux clutch means mounted between the operating means and the ram to drive the latter only through a magnetic eld coupling, inductive means in said magnetic flux clutch for providing said field, a source of power, conductive means connecting Vsaid source with the inductive means for the clutch, dynamic flux braking means connected to the operating means, a second inductive means in said braking means to provide vthe magnetic eld therefor connected to the source of power, switching means in the circuit of the rst inductive means of both manual and cam controlled type actuated by press movement 'to energize the clutch field for driving the ram and deenergize the same upon the press reaching a predetermined point, and second switching means of both relay and cam controlled type connected in the circuit to the second inductance to control the energized periods of the brake field, one of the second switching means including a speed responsive member for actuating a switch, said speed responsive member connected to. the operating means to open upon the speed thereof being reduced below a predetermined 'value so that the dynamic brake eld is deenergized as the mechanism comes to rest.

4. In a control system for a press, a source of alternating current power, a motor connectsable to said power, rotatable means for driving said press, magnetic flux clutch means between the motor and the rotatable driving means, energizing coils mounted in the clutch means, dynamic iiux brake means associated with the rotatable means to stop the same, a second series of energizing coils for the brake means, rectifying means connected to said source of power, means for connecting said two series of coils in parallel across the rectier output, resistance means in series with the energizing coils for the clutch and shunting means for the resistance means including relay switching means to vary the iiow of current through the clutch coils and therefore the strength thereof.

5. In a control system for a press, a source oi alternating current power,I a motor connectable to said power, rotatable means for driving said press, magnetic iiux clutch means between the motor and the rotatable driving means, energizing coils mountedin the clutch means, dynamic ux brake means associated with the rotatable means to stop the same, a second series oi energizing coils for the brake means, rectiying means connected to said source of power, means for connecting said two series of coils across the rectifier output, relay switching means connected to the energizing coils for the brake means,

aeeaaoo and speed conscious control means mounted on the rotatable means and connected to the relay switching means to control the energization of the iiux brake coils with regard to speed of movement.

6. In a control system for a press, a source of alternating current power, a motor connectable to said power, rotatable means for driving said press, magnetic iiux clutch means between the motor andthe rotatable driving means,` energizing coils mounted in the clutch means, dynamic iiux brake means associated with the rotatable means to stop the same, a second seriesof energizing coils for the brake means, a solenoid released friction brake applied to the rotatable means, means interconnecting the source of power and the two series oi coils in parallel, relay coil means in series with the energizing coils of the flux clutch, and switching means controlling the solenoid released friction brake operated by the relay coil means so that the friction brake will not be released unless current is flowing through the clutch coils.

7. In a control system for a press, a source of alternating current power, a motor connectable to said power, Arotatable means for driving said press, magnetic iiux clutch means between the motor and the rotatable driving means, energizing coils mounted in the clutch means, dynamic flux brake means associated with the rotatable means to stop the same, a second series of energizing coils for the brake means, rectifying means connected to said source of power, means for connecting said two series of coils across the rectifier output, resistance means and relay coil means connected in series with the energizing coils for the ux clutch, and control switching means operated by the relay coil means to provide control dependent upon the energization of the flux clutch coils.

8. In a control system for a press, a source of alternating current power, a motor connectable to said power, rotatable means for driving said press, magnetic ux clutch means between the motor and the rotatable driving means, en'- ergizing coils mounted in the clutch means, dynamic flux brake means associated with the rotatable means to stop the same, a second series of energizing coils for the brake means, a solenoid releasing friction brake applied to the rotatable means, rectifying means connected to the power source and to the two series of coils, transformer means connected to the source and to the solenoid, relay coil means connected in series with the clutch coils, and switching means operated by the relay coil means and controlling the solenoid friction brake so that the brake will not be removed unless current is fiowing through the clutch coils.

9. In a control system for a press, a source of alternating current power, a motor connectable to said power, rotatable means for driving said press, magnetic ux clutch means between the motor and the rotatable driving means, energizing coils mounted in the clutch means, dynamic flux brake means associated with the rotatable means to stop the same, a second series of energizing coils for the brake means, a solenoid released friction brake applied to the rotatable means, rectifying means connected to the power source and to the two series of coils, transformer means connected to the source and to the solenoid, and relay coil means and resistance means connected in series with the iiux clutch coils.

l0. In a control system for a cyclically operating press machine, a source of power, driving means connectable to said source, operating means for the press, magnetic clutch means between the driving means and the operating means, dynamic ux braking means applicable to the operating means, mechanical solenoid brake means applicable to the operating means, switching means for controlling the clutch and brakes to initially energize the flux clutch and remove the magnetic brakeat the beginning of a cycle in moving from a position of rest, energize the flux brake, deenergize the iiuX clutch and apply the friction brake when the press is in clamping position at an intermediate portion of the cycle, and further switching means actuated at the termination of the clamping portion of the cycle to again cause actuation of the rstnamed switching means to energize the ux clutch and remove the friction brake to return the apparatus to a position 0f rest.

ll. In a control system for a press, .a source of power, a motor connectable to said source, ro tatable means for driving said press, magnetic ilux clutch means between the motor and the rotatable driving means, energizing coils mounted in the clutch means, dynamic flux braking means and mechanical solenoid braking means applicable to the operating means, energizing coils in the flux braking means, combination relay and cam controlled switching means to energize the flux clutch coils and remove the friction brake to cause the press to move from a position of rest to a position slightly in advance of the clamping position and then deenergize the iiux clutch, energize the flux brake and then apply the friction brake to stop the press in clamping position to perform work on a clamped part, and additional switching means actuated by the completion of the acts performed upon the clamped part to cause the clutch and brake control switching means to recycle to bring the press back to a position of rest.

l2. In a control system for a press, a source of power, a reversible motor, switching means for connecting the motor to the source of power for rotation in either direction, rotatable means for driving the press, flux clutch means between the motor and the rotatable driving means, energizn ing coils for the clutch means, magnetic flux brake means associated with the rotatable means to stop the same, energizing coils for the iiuf; brake means, solenoid released friction brake means applicable to the rotatable means, switching means for operating said clutch and brakes in timed sequence to produce an operating cycle when the motor is driving in one direction and further switching means to controlthe clutch and brakes to drive the press in the reverse direc tion only as long as the further switching means is held.

WILLIAM DE LOHR- BERRY.

No references cited.

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