US2676687A

US2676687A - Press having an antirepeat control

Info

Publication number: US2676687A
Application number: US162213A
Authority: US
Inventors: Sterling D Millhouse
Original assignee: Revere Copper and Brass Inc
Current assignee: Revere Copper and Brass Inc
Priority date: 1950-05-16
Filing date: 1950-05-16
Publication date: 1954-04-27
Anticipated expiration: 1971-04-27

Description

April 27, 1954 s. D. MILLHousE 2,675,687 PRESS HAVING AN ANTIREPEAT CONTROL F'iled May 16, 1950 5 Sheets-Sheet l g h il 765 w 0 @22111-9 j* l l 2, y .s -Il; ,ffl w l l M will" NIW" "Il Mh I LJW,

April 27, 1954 s. D. MILLHOUSE 2,676,687 PRESS HAVING AN ANTIREPEAT CONTROL Filed May 16, 1950 5 Sheets-Sheet 2 April 27, 1954 5.2m. MILLHoUsE PRESS HAVING AN ANTIREPEAT coNTRoL Filed May 16, 1950 5 Sheets-Sheet 5v- April 27, 1954 s. D. MILLHousE PRESS HAVING AN ANTIREPEAT CONTROL 4Filed May 16,l 1950 5 Sheets-Sheet 4 April 27, 1954 s. D. MILLHOUSE 2,676,687

PRESS HAVING AN ANTIREPEAT coNTRoL Filed may 1e, 195o 5 Sheets-Sheet 5 Patented Apr. 2'?, 1954 UNITED STATS PRESS HAVINGAN ANTIREPEAT CONTROL Sterling D. Millhouse, Rome, N. Y., assigner to Revere Copper and Brass Incorporated, Rome, N. Y., a corporation of Maryland Applicationll/ay 16, 1950, Serial No. 162,213

v14 Claims.

My invention relate to presses `fory shaping blanks by use of cooperating dies, the ypress having provision for causing the press head to-be normally maintained in such position as `to cause the dies to be separated so that the blank. may be inserted between them,` the press also having operator actuated control means whichv when actuated causes the press head to move through its working stroke to close the dies and then return to its normal position. and stay there until the control means is again actuated. `The invention particularly relates to the provision of means for insuring against .the possibility of the operator having either of his hands between the dies during the working stroke of the press head and for preventing the press from accidentally making the working stroke when it is not desired to have it d so.

En the drawings:

Fig. l is an elevation of a press according to the invention, with parts omitted;

Fig. 2 is a side elevation of the press according to Fig. l, with parts omitted;

Fig, 3 is a schematic diagram of the apparatus for operating and controlling the press; and` Figs. i to 8 inclusive show across the line diagrams of the electric circuit connections according to Fig. 3 with the parts in diierent operative position, respectively, these figures also showing a control switch for thel press, and the press cylinder and its distributing valve, in dilerent operative positions corresponding to the positions of parts in these across the line diagrams.

Referring particularly to Figs. 1, 2 and 3, the press comprises the base l on which is mounted a supporting frame 3. On this frame is reciprocally mounted a vertically moving lpress head 5, the latter carrying a die part, conventionally shown at l, which part cooperates with a second die part, conventionally shownat 9, carried by the base of the press. For reciprocating the press head shown a piston l mounted for reciprocation in the vertical cylinder t3 carried bythe frame of the press, the piston rod I 5 connecting Ythe piston to the press head so that when the piston is reciprocate'd the press head will recwcate with it.

In: the embodiment of the invention shown an operator controlled reciprocatory distributing valve l'i or the piston type, fitting the-bore of the valve casingl I9 (Figs. 2 and 3) in a uid tight manner, is provided for controlling'the reciprocations or the piston H. Normally this valve is maintained at the left hand end of its travel, Aas viewed in Fig. 3, for admittingl pressureuid from a source of 'supply to 'the-lower end of the Y cylinder and for connecting `the uppe;1 end of the vcylinder to exhaust Yso as -to maintain lthe press head at the upper end: of vitsstroke-for holding the two f die parts in separated relation. B'y''the' operator-causing the valve to moveto-the (Cl. 12R-131) right hand end of its travel pressure fluid will be admitted to .the upper end of the cylinder while the lower lend of the cylinder will be connected to exhaust for causing the piston to make a downward stroke for ciosing the die parts. In the embodiment of the invention illustrated when the piston reaches the lower end portion of its stroke the valve .is automatically shifted to the first mentioned end of its travel, causing the piston to move to the upper end of its stroke and to be maintained therein until the operator again causes the valve to move to the right hand end of its travel.

In the present embodiment of the invention, for casing the distributing valveto move to that end of its travel which causes the press head to make its downward stroke, a pair of push buttons 2l and 23 are provided, each of these push buttons being of a common type in respect to the switch part thereof being biased into open position by a compression spring or the like (not shown) so that the switch part will automatically open upon the push button being released by the operator. The circuit connections are such that both push buttons must be depressed to close them before the controlling valve can be so moved. Also the push buttons are positioned far enough apart so that the operator mustv employ both hands to depress them. The circuit connections are further such that after the piston makes a downward stroke both the push buttons must be released by the operator before the distributing valve can be shifted out of its normal position to cause the press head to make a second downward stroke.

In normal operation the operator dips the blank in a so-called drawing compound which is commonly an oily liquid and then places it on the lower die part 9 with the presshead at the upper end of its stroke. He then olepressesY both push buttons to cause the press head to make its downward stroke, the press head automatically returning to the upper end of its strokeA after it has operated upon the blank to shape it, whereupon theY operator removes the finished work from the lower die and places a new blank thereon. yThe time it takes for the press head to make its downward stroke, and the placing of the push buttons a considerable distance from lthe path of travel of the upper die part-make it next to impossible for the operator to get either of his hands between the dies while the downward stroke of the press head takes place. Furthermore, because both push buttons must be permitted to open before `the press head can make a second downward stroke,A the press is rendered inoperative in case either push button becomes short circuited or tails to `open upon-being released. Heretofore, when-it was 4attempted to control thepressby a pair of push buttons, the circuit aereos? connections were such that if one push button became short circuited, say by the drawing compound seeping into it, or became mechanically defective so that it would not open when released, neither of these circumstances would be discovered until the other p-ush button became short circuted or defective, in which case when said other push button became short circuited or defective the press would repeat its downward stroke and in some instances while the operator had his hands between the dies in inserting the blank or removing the finished work, with very distressing results. Still further, when heretofore attempting to control a press by a pair of push buttons, it was possible for the operator to prop one push button in depressed position and operate the press by use of the remaining push button, thus leaving one of his hands free to manipulate the blank, with the result that if the last mentioned push button became short circuited the press would repeat its downward stroke and sometimes while the operator had his iree hand between the two die parts, again withdistressing results. All these possibilities o the press accidentally repeating its downward stroke are eliminated by the present invention.

As indicated in Figs. l, 2 and 3, an electric motor 25 is provided for driving a pump 2l, the motor, as shown, being energized by the line having the leads 29, in which line is conveniently interposed a suitable switch or starter (not shown) for establishing and interrupting operation of the motor as desired. When the press is in operation normally the motor will be continuously operated. Conveniently the motor and pump are mounted on the frame of the press as shown by Figs. l and 2.

As diagrammatically shown by Fig. 3, the pump 2l has an inlet. or suction pipe 3l in communication with an oil tank or sump 33 so that the pump will draw oil from said tank and discharge it under pressure into the outlet pipe 35 or the pump. Excess pressure in the outlet pipe be prevented by use of a pressure relier` valve in a pipe 39 connecting the outlet pipe to the oil I tank 33.

The outlet pipe S of the pump 2l', as shown by Fig. 3, opens into the distributing valve casing i3 through a port il@ midway the length of that casing. Near one end the valve casing has an s exhaust port il connected by a pipe t3 to the oil tank 33. Near its opposite end it has a second exhaust port 45 connected by a branch pipe fil to the pipe 43. As further shown, the valve casing has a port et operatively positioned between the ports le and lis, which port le is connected by a pipe 5i to the upper end of the cylinder I3, and has a further port 53 operatively positioned between the ports lil and di, which port 53 is connected by a pipe 55 to the lower end of the Cylinder. The distributing valve il, as shown, is provided with the spaced annular grooves 5l and 59. When the valve is in its position shown by Fig. 3 the groove 5l will connect the inlet port 'd to the port 53 to admit pressure fluid from the pump through the pipe lili to the lower end of the cylinder, while the groove 5&3 will connect the port lle to the port iii to connect the pipe 5l to the exhaust pipe il so as to exhaust the upper end of the cylinder and thus maintain the piston and press head at the upper ends of their strokes. When the valve is shifted to the opposite end of its travel, as shown or example in Fig. 6, the groove 59 will connect the inlet'port 40 to the port 49 to admit pressure fluid from the pump through the pipe `5i to the upper end of the cylinder, while the groove 5l will connect the port 53 to the port lil to connect the pipe 55 to the exhaust pipe i3 so as to exhaust the lower end of the cylinder and thus cause the piston to make a. downward stroke. After the piston reaches the end of its downward stroke shifting of the valve from its position shown by Fig. 6 to that shown by Fig. 3 will cause the iston and press head again to return to the upper ends of their strokes where they will remain until the operator again causes the valve to shift to its position shown by Fig. 6.

As illustrated, the distributing valve Il is shifted to the end of its travel opposite that shown in Fig. 3 by the operator causing a solenoid -l to be energized for drawing into the solenoid "n associated armature t3. This armature is shown as connected by a rod 65 to one end of a lever 6l (Figs. 2 and 3) pivoted intermediate its length, at t9, to a stationary bracket "il carried by the frame of the press, the opposite end of this lever being connected by a link i3 to the outer end of one arm of a bell crank lever lli, the outer end of the other arm of the bell crank lever being pivotally connected to the valve stem ll', while the bell crank lever adjacent the juncture or its two arms is swingingly connected by a link 'i9 to the valve casing .59. Cooperating with the armature @3 is a compression spring 8l which normally holds the valve in its position shown by Fig. the solenoid ti when energized drawing the armature t3 downward, as viewed in Fig. 3, against the upwardly exerted force of this spring so as to shift the valve.

For energizing the solenoid (il so as to shift the distributing valve il to the right as viewed in Fig. 3, and for deenergizing the solenoid to permit the spring 8i to return the valve to the position shown by Fig. 3 and be maintained in that position, the terminals of the solenoid are shown as connected by leads S3 and t5 to the stationary contacts 8l and S9, respectively, of a normally open switch 9i) having a further stationary contact Eli adapted to be placed in electrical communication with the contact Si by a movable contact 33, the switch also having a still further stationary contact adapted to be placed in electrical communication with the contact St by a further movable contact el. The contacts ill and t5 are shown as connected by leads S8 and se to leads itl and w3, respectively, which leads lill and lila are shown as tapped oil of two o1 the leads :29. The movable contacts Si?, and ill are diagrarninatically shown by Fig. 3 as carried in insulated relation to each other by a rod m5 with which cooperates a compression spring lill for normally holding the switch in open position. For closing the switch the rod carries an armature lil@ with which cooperates a solenoid l l l for drawing the rod downward against the upwardly exerted force of the compression spring for closing the switch when the solenoid is energized. As diagrammatically shown, the rod lll5 also carries the movable contact lift with which cooperate the contacts lle and lll forming a switch part which is closed when the switch part comprising the contacts 93 and ill is closed.

For energizing the solenoid lll of the switch t, so as to cause the distributing valve l1 to move to the opposite end of its travel to that shown in Fig. 3, one terminal of the solenoid is shown as connected by a lead l le to one side i2i of a line, the opposite side of which line is constituted by a lead |23. The leads constituting the opposite sides oflthis-llineareA shown'as connected to the-.opposite terminals, respectively, of the secondary winding of a-step down transformer |25 the primarywinding of which is energized by the line'formed by the leads ||I| and w3. The otherterminal'of the solenoid is shown as connected by a lead |21 to the stationary contact '|29of a switch |3| having a second stationary contact |33, which two contacts are adapted vto -placed in electrical communication by a movable contact |35 when the solenoid |31 of the switch-ISI is energized. The

The push buttons 2| and 23 hereinbefore mentioned are diagrammatically shown in Fig. 3 'as being of the 4i-pole single-throw type, two of the poles or contacts l5 |l and |53 of each of which are connected by the leads |55 and |51 to opposite sides, respectively, ofthe line |2|, |23, while the other two poles orcontacts |59 and ISI of each of which are connectedfby theleads |63, |65 to the opposite terminals of thesolenoids |31 of the two switches |3|, respectively. It will be observed from the across the line diagram of Fig. 4 that connecting the push button circuits across the line in parallel and the employment of 4-pole push buttons serve to isolate each solenoid |31 from both sides of thevline when the push button for energizingthat solenoid is open, and that this reduces to a minimum the possibility of ground currents by-passing either push button and energizing the solenoid associated with it.

From the above it will be observed that the two switches |35 each comprising the pair of contacts |255, |33 are connected in series, and therefore that both must be closed -by energization of their solenoids IS'i-by depression of the two push buttons 2| land 23 to complete the circuit which energizes the solenoid so that the solenoid 6| will be energized to cause the valve |'i to shift to the right from its position shown by Fig. 3 to cause the press head to make a downward stroke. As hereinafter explained, the switches |3| are tripped into-open position by such shifting of the valve, which tripping of said switches, if means were'not provided to prevent it, would cause the solenoid I to be deenergized so that the spring |81 would open the switch part comprising the movable contacts 53 and 91 and return the valve to its position shown by Fig. 3 before the downward stroke of the press head was completed. For preventing such action the movable contact ||3 -of the switch 90 when it contacts with the stationary contacts 5 and I1 oi that switch establishes a holding circuit for the solenoid Hi tok keep -it energized until such holding circuit is interrupted. This'holding circuit is established by the lead |1| (Fig. 3) which connects thecontact ||5 to one" terminal of the solenoid i i, andby the lead" |13'whichconnects the-opposite contact Y| |1-to ther lea-d'MI at thek point |1|l.- VItwill be observed that'by'these con- -at 2|5, .the spring ith and weight ofthe p nections the holding circuit shunts the two series connected switches |3l, the holding circuit being connected across the linein parallel with the push button circuits for those switches, and containing connected in series the normally closed switch` |133, lthe normally closed push button |41, and the switch part having the movable contact |l3, as more clearly shown in the across the line diagram of Fig. 6.

The push button |41 is of a common construction in which the switchpart thereof is biased into closed position by a compression spring so that the switch part will automatically close when the push button is released. This push button is provided for interrupting4 the above described holding circuit at any time while the press head is making its downward stroke so that the solenoid I I will be deenergized to cause deenergization of the solenoid 6| and thus permit the spring 8| to shift the valve to its position shown by Fig. 3, with the'result of causing the press head to return `to the upper end of its stroke before making a complete downward stroke.

The switch m3 hereinbefore mentioned, as diagrammatically illustrated, comprises a lever llt pivoted for swinging movement at |11. The lever carries in fixed relation thereto a contact |13 which cooperates with a stationary contact |3| to which the lead |135 providing part of the holding circuit is connected. The switch is normally held in closed position by a tension spring |83 'connected to one end of the lever. At its end opposite the spring the lever is shown as carrying a vertically adjustable screw |35 the upper free end of which is adapted to be struck by the member |31 of insulating material carried by the press head whenv the latter reaches the desired extent of its downward movement. This member ll', when it so strikes the screw, will swing the lever about its pivot to move the contact |13 from engagement with the contact isi so as to open the holding circuit, as shown in Fig. 8, and thereby cause the solenoid 6| to be deenergized to permit the spring 3| to shift the valve from the right hand end of its travel to its left hand end, as viewed in Figs. 3 and 8, to cause the press head to make its upward stroke.

The two switches |3| are alike except that one, as viewed in Figs. 2 and 3, is a mirror image of the other, that is to say, one is of right construction and the other of left construction. A description of one therefore will suflice-for the other. As shown by Fig. 4, cooperating with the solenoid |31 of the switch is a verticallymovable armature |39 having an extension iti pivoted at |93 to a lever |55 intermediate the length of the latter. This lever ist is nivo-ted at one at |31, for swinging movementand is heid in its position shown by Fig; 4 Yby-a compression spring its bearing at one end against the ley and at its opposite end against a fixed abutr Zei. At its free end the lever is shown pivotally connected at 2&3 to one end of a li t V201i, the other endof which linkis pivotally co `nected at 251 to the outer end of a` lever 2&9. The

lever 239 is pivotally connected at iii! at 'intermediate portion of its length -to the outer end portion of a further lever 2|@ swingingly pivoter?,

connected to therlever 259 .normally causing lever 2 B3 to rest against a stop 3|?.` As diagram- `matically shown, the lever 2 i3 adjacent its outer end carries atits upper side aninsulatingblock 2 i 9, which l'block carries lanupwardlyprojecting pin 22| on which the contact |35 is slidably and loosely mounted, a light compression spring 223 surrounding the pin and bearing at opposite ends against the block 2|9 and contact |35, respectively, causing that contact yieldably to adjust itself against the contacts |29 and |33 when the lever 2|3 is swung upwardly to close the switch. As further diagrammatically shown, the switch ESI comprises a lever 225 pivoted at one end for swinging movement at 221, the opposite free end of the lever resting against the upper side of one end portion of a still further lever 229, which latter is pivotally mounted, at 23|, intermediate its length for swinging movement, a compression spring 233 bearing at its lower end against the abutment 20| and bearing at its upper end against the lever 22% normally holding the outer end o that lever against a stop 235. As shown, the lever 225 has an upwardly projecting portion 231 the upper free end of which is adapted to 'cooperate with the notched. end portion 239 of the lever 2d@ for a purpose hereinafter described.

When the parts are in their positions shown by Fig. fi, and the push buttons 2| and 23 are depressed for energizing the solenoids 31 of the switches Iii, the armature E89 of each switch will be drawn upwardly against the resistance of the spring |99 to swing the lever 2F59 about its pivot 2|I and cause the notched end portion 239 of that lever to contact with the upper end of the vertically projecting portion 231i of the lever 225. Under these conditions the upper end of the projection 231 acts as a fulcrum for the lever 229 to cause the latter, upon continued upward movement oi the armature |33, to swing the lever 2|'5 about its pivot 2&5 and move the parts into their positions shown by Fig. 5, in which positions the switch ISI is closed. The depression oi both oi the push buttons and 23 causes both of the switches ISI to close in this way, for energizing the solenoid I I I as above explained. When the solenoid il! is thus energized the switch part comprising the contacts 23 and e1 closes to energize the distributing valve controlling solenoid SI also as above explained. At the same time the energization of the solenoid III closes the switch part comprising the 'Contact H3 so as to establish the above den scribed holding circuit for the solenoid III so as to maintain energization of the solenoid i! upon opening of either or both of the switches ISI, all of which will be clear from the across the line diagram shown by Fig. 5. When the circuit connections shown by Fig. 5 are completed the solenoid I shifts the valve il to the right hand end ci its travel, as shown in Fig. 6, so as to cause the piston i! and press head to make their downward strokes.

As shown in Fig. 2, the two switches ISI are carried by the oil tank 33 above the lever 61, which latter is swung downward for operating the valve |1 when the solenoid 6I is energized. The outer ends of the levers 229 of the two switches ISI project toward each other from the casings of those switches, and to such end of each lever is connected a chain 24|, the lower ends of which chains are connected to the upper end of a tension spring 243, the lower end of this spring being connected by a wire or the like 245 to the lever 51 adjacent the pivotal connection of the rod 65 to one end of that lever. When the solenoid 6| is energized to swing this end of the lever 61 downward the connections between the lever and the two levers 22S will pull each lever 229 downward from its position shown by Fig. 5 to its position shown by Fig. 6, the spring 2l3 preventing the application oi an excess force to the levers 229. Such movement of the lever 229 of each switch |3| moves the upper end of the upwardly projecting member 231 of the lever 225 of that switch from under the notched end 239 of the lever 209, which will cause the lever 2I3 of the switch to drop and move the contact |35 downward and thus open the switch, the parts of the switches ISI then being in their positions shown by Fig. 6 if the push buttons 2| and 23 are still closed to energize the solenoids |31, or in their positions shown by Fig. 7 if the push buttons 2| and 23 are released to deenergize the solenoids |31 and permit the springs 29 to swing the lever |95 to their downward positions. It will be observed that when the switches |3| are tripped by the levers 229 neither of those switches can be closed again by depressing either of the push buttons 2| and 23 until the trip mechanism of each switch is reset by movement of the lever 22S of that switch back to its position shown by Fig. 4.

When the piston Il reaches the downward end portion of its stroke and opens the switch It?, the holding circuit will be interrupted, as clearly indicated by the across the line diagram shown by Fig. 8. This will deenergize the solenoid III to permit the spring |61 (Fig. 3) to open the switch part comprising the contacts 93 and 91 for deenergizing the valve controlling solenoid El. When the valve controlling solenoid 5| is deenergized in this way the spring 8| (Fig. 3) will move the valve I1 again to the left hand end oi its travel, as shown in Fig. 8, for admitting pressure fluid to the lower end of the cylinder i3 and exhausting it from the upper end of the cylinder so as to cause the piston and press head to move to the upper ends of their strokes. The switch |43 closes during the upward stroke of the press head 5 because of the member |31 (Fig. 3) carried by the head moving out of con tact with the screw |85, but, as the deenergization of the solenoid III when the switch It?) opened causes opening of the switch part comprising the movable contact I3, the solenoid I I will not be reenergized by such closure of the switch m3 until each push button 2| and 23 is released and again depressed for closing the switches I3|. In these connections it will be noted that when the spring 8| swings the left hand end of the lever 51 upward the compression spring 233 0I" each switch I3| will move the le ver 22? oi that switch to its position shown by Fig. 8, so that when the push buttons 2| and 23 are again depressed by the operator upon the piston reaching the upper end of its stroke the upper end of the portion 231 of each lever 225 will be in position to cooperate with the notched end of the associated lever 229.

Also it will be noted from Fig. 6, which indicates the push buttons 2| and 23 in closed position and the piston making a downward stroke,

, that although by opening the push button lli? the valve i? will be shifted from its position shown by Fig. 6 to the left hand end of its travel to cause the piston to return to the upper end of its stroke without making a complete downward stroke, such opening of the push button li'l will not reset the trip mechanism of either switch Ii, although the lever 229 will be returned to its position shown by Fig. 8, because the notched end 239 of the lever 209 will be in position to cooperate with the projection 231 of 4the lever 225'on1y if the solenoid l31" for operatin'g'each lever 209 is rstdeenergized by openingr of the push buttons 2| and 23 to place the parts of the'switches |3| `and ofthe parts shown bythe across the -line diagrams in their positions shown by Fig. 4, which positions are exactly like that shown by Figy except that in the last mentionedngure the switch 143 is open. Thus should either push button 2l or 23 become short circuited it will be impossible by use of the push button I4? to reset the tripv mechanism of that switch I3! which the short circuited push button controls. Only by correcting the short circuit, so that the solenoid |31 controlled by the short circuited push button may be'deenergized, can the trip mechanismbe reset.

It will be understood that within the scope of the appended claims Awide deviations may be made from the form of the invention described without departing from the spirit of the invention.

I claim:

l. Control mechanism for a press or the like having a member which is reciprocated in a work stroke and a return stroke and also having mechanism governing the supply of energy thereto comprising a movable element which has a rst position which provides a flow of energy effective to move said member. in Vits'return stroke and a second position which provides a flow of energy effective to move said .member in its work stroke, said control mechanism comprising means for moving said element from' its said first position to its said second position comprising circuit means controlled jointly by a pair of operator controlled switches which-'only when both are closed causesaid circuit means to be energized for so moving said element; aseparate circuit breaking means associated with each of said operator controlled switches tripped into open position when said elementis so moved for rendering that associated switch inoperativev to control said circuit means, andmeans for'resetting each of said circuit breakingmeans controlled by. opening of the operator controlled switch associated with it.

2, Control mechanism for a press or the like having'a member which isreciprocated in a work stroke and a returnstroke and also havingmechanism governing the supply of energy thereto f comprising a movable element which `has a rst position which provides a low of energy effective to move said member in its return stroke and a second position which provides a now of energy effective to move said member in its Vwork stroke, said control mechanisn'i.` comprising means for moving said eiement from'its said first position to its said second position comprising circuit means controlled jointly by a pair of operator controlled switches which only when both are closed cause said circuit means to be energized for so moving said element, a separate circuit breaking means associated withv each of said operator controlledswitches tripped.. into open position when said element is so moved kfor rendering that associated switch inoperative to control said circuit means-means for causing movement of said element from its said secondposition to its said iirstposition after it has been so moved to its said second position, and means for' resetting each of said circuit ybreaking means operated jointly in responsetothe last mentioned movement of said element and the opening ofv the operatorcontrolledi switchassociated with that icircuit breaking means.

3. Controlimechanism forl apress or the like having a member which vis reciprocated in a Awork stroke and a return stroke and also having' mechanism governing the supply of' energy thereto comprising a movable element which has a rst position which provides a iow ci energy eiective to move said member inits return stroke and a second position whichprovides a flow of energy effective to move said member in its work stroke, said control mechanism comprisingv means for normally maintaining said element in itssaid first rposition for holding said member at the end of its return stroke, operating means for said element comprising a circuit energized by closure of a pair oi switches in series for moving said element from its said first position to its said second position for causing a work stroke of said member, means for trippingsaid switches, and means for establishing a holding circuit for said operating means in shunt with said switches, upon said iirst mentioned circuitbeing sov energized; means for automatically interrupting said holding circuit when said member reachesthe end portion of its work strokeV for causingrmovement of said element from its saidsecondposition to its said rst position forA returning said member to the end' of its return stroke, and means for separately closing said switches-comprising a separate circuit for eachand a'pair of operator controlled switches, each off said latter for separately controlling those: circuits, `each operator controlled switch when closed energizing the circuit controlledl by it. for closing the associated switch of said pair of switches; each operator controlled switch-when released by the operator -automatically openingfor ldeenergizing the circuit controlled by it,"the meansfor tripping said switches beingV operated into reset position jointly in response to deenergization of :both of said circuits controlled by saidoperator controlled switches and theinterruption of said holding circuit.

4. Control mechanism for a press or the like according to claim 3 in which each operator controlled switch is a four-'pole single-throw switch, the means for closing the switches ofthe pair of switches in series comprising 'a'separate solenoid for each of those switches energized by `closure ofsaid operator controlled switches, respectively, the terminals of each solenoid being connected to a pair of the poles of said operator controlled switch and the other pair of said poles being connected to opposite sides of a line for isolating the solenoid from both sides of said line when the operator controlled switch is open.

5. Control mechanism for a `press or thev like according to claim 3 in which a normally closed switch is included in the holding circuit, which switch when opened interrupts the holding circuit formoving the element from its second position toits rst position, said holding circuit and the circuits controlled by theoperator controlled switches being connected across theline in parallel. f

6. Control mechanism for a press or the-like havingY a` member which is reciprocated inawork stroke and a return stroke and also having mechanism governing the supply of energy thereto comprising a movable element which-has a-irst position which provides a flow of energyv effective to move said member in its return-stroke and al second position which provides a iiowv of energy effective to move said member in its workv stroke, said control'me'chanism comprising; means=-for normally maintaining said yelement-in its-.said

nrst position for holding said member at the end of its return stroke, operating means for said element having a controlling circuit comprising a pair oi switches in series which when closed cause said operating means to move said element from its said iirst position to its said second position, a separate operating means for each of said pair oi switches comprising a circuit having an operator controlled switch normally biased into open position and which when closed by the operator causes the last mentioned operating means to close such switch of said pair of switches, a separate trip mechanism for each switch of said pair of switches for automatically tripping the switch into open position when both switches of said paii1 or switches are closed for causing said element to move from its said iirst position to its said second position, and resetting means for each trip mechanism controlled jointly by movement of said element from its said second position to its said iirst position and deenergization of the circuit for the operating means for that switch.

7. Control mechanism for a press or the like having a member which is reciprocated in a work stroke and a return stroke and also having mechanism governing the supply of energy thereto comprising a movable element which has a rst position which provides a now oi energy eiiective to move said member in its return stroke and a second position which provides a flow of energy effective to move said member in its work stroke, said control mechanism comprising means for normally maintaining said element in its said iirst position for holding said member at the end of its return stroke, operating means ior said element having a controlling circuit comprising a pair of switches in series which when closed cause said operating means to move said element from its said iirst position to its said second position, a separate operating means for each of said pair of switches comprising a circuit having an operator controlled switch normally biased into open position and which when closed by the operator causes the last mentioned operating means to close such switch of said pair of switches, a separate trip mechanism for each switch of said pair of switches for automatically tripping the switch into open position when both switches of said pair of switches are closed for causing said element to moveirom its said first position to its said second position, and resetting means for each trip mechanism controlled jointly by deenergization o both said controlling circuit and said circuit for the operating means for the switch adapted to be tripped by the trip mechanism.

8. Control mechanism for a press or the like having a member which is reciprocated in a work stroke and a return stroke and also having mechanism governing the supply of energy thereto comprising a movable element which has a iirst position which provides a flow of energy effective to move said member in its return stroke and a second position which provides a iiow of energy effective to move said member in its work stroke, said control mechanism comprising means for normally maintaining said element in its said irst position for holding said member at the end of its return stroke, operator controlled means -for moving said element into its said second position when said member is at the end of its return stroke, automatic means for moving said element into its said iirst position when said member is at the end of its work stroke, said operator controlled means comprising a circuit having a pair of switches connected in series, which circuit when said switches are both closed causes said operator controlled means to move said element into its said second position, said operator controlled means also comprising separate circuits each for operating a separate one or said pair of switches, each oi said separate circuits being controlled by an operator controlled switch which when closed by the operator energizes the circuit having the same to cause closing of the associated switch of said pair of switches, a separate trip means associated with each switch of said pair of switches for automatically tripping that switch upon closure ci both oi those switches, and means for separately resetting said trip means upon both the operator controlled switch controlling the circuit for closing the associated switch of said pair of switches being opened and said automatic means acting to move the element from its said second position to its said first position.

9. Control mechanism for a press or the like having a member which is reciprocated in a work stroke and a return stroke and also having mechanism governing the supply oi energy thereto comprising a movable element which has a rlrst position which provides a flow of energy effective to move said member in its return stroke and a second position which provides a flow of energy eiective to move said member in its work stroke, said control mechanism comprising means for normally maintaining said element in its said nrst position for holding said member at the end oi its return stroke, operating means for said element having a controlling circuit comprising a pair of switches in series which when closed cause said operating means to move said element from its said iirst position to its said second position, a separate operating means for each of said pair of switches comprising a circuit having an operator controlled switch normally biased into open position and which when closed by the operator causes the last mentioned operating means to close such switch of said pair oi switches, a separate trip mechanism for each switch of said pair of switches, each trip mechanism comprising a first part and a second part each movable into and out of a position in which they cooperate with each other for rendering said operating means for the switch operative and inoperative, respectively, to close said switch, the said first part when moved out of such position tripping the switch from closed to open position, said controlling circuit for said operating means for said element comprising a holding circuit for shunting said pair of switches when the latter are in open position and said element is in its said second position, a normally closed switch connected for operatively interrupting said holding circuit when that switch is opened, means for opening the last mentioned switch in response to movement of said member to the end of its work stroke for opening said holding circuit to interrupt the controlling circuit for the operating means for the element so as to cause said element to ve from its said second position into its said first position and to cause said nrst part of each trip mechanism to move into its position in which it is adapted to cooperate with said second part of said mechanism, and means operated only in response to deenergization of said controlling circuit fcr closing each switch of said pair oi switches for moving said second part of each of said mechanisms into its position in which it 13 cooperates with said first part of that mechanism.

10. Control mechanism for a press or the like having a member which is reciprocated in a work stroke and a return stroke and also having mechanism governing the supply of energy thereto comprising a spring-pressed movable element which has a rst position to which it is moved by the spring, in which position it provides a ow of energy eiTective to move said member in its return stroke and a second position which provides a ilow of energy eiective to move said member in its work stroke, said control mechanism comprising a solenoid for moving said element against the resistance of the spring to its second position, circuit means comprising a switch for energizing said solenoid when said switch is closed, a second spring for normally holding said switch in open position, a second solenoid for moving said switch into closed position against the resistance of said second spring, circuit means for energizing said second solenoid for'so moving said switch into closed position comprising a second and a third switch in series with said second solenoid, circuit means comprising separate solenoids for operating said second and third switches, respectively, into closed position for energizing said second solenoid whereby to cause the latter to close the rst mentioned-switch for energizing the element operating solenoid for causing the latter to move the element to its said opposite end of its travel, circuit means having separate operator controlled push buttons for, when closed, separately connecting said solenoids for said second and third switches in parallel across a line for separately energizing those solenoids, separate trip mechanisms associated with said second and third switches, respectively, each trip mechanism having means operated in response to energization of said element operating solenoid for tripping such associated switch into open position and each having means operated in response to deenergization of both said element operating solenoid and the solenoid for such associated switch for resetting said mechanism to permit the associated switch again to be closed by energization of its solenoid, a holding circuit comprising a fourth switch operated into closed position, by said second solenoid when the latter is energized upon said push buttons being closed by the operator, for establishing a shunt connection around said second and third switches for continuing the energization of said second solenoid when said second and third switches are so tripped into open'position, a fth switch in series with said second solenoid adapted to be moved into open position by movement of said member to the portion of its work stroke for deenergizing said second solenoid and consequently the element operating solenoid for resetting said trip mechanisms when the solenoids for said second and third switches are deenergized by the operator permitting said push buttons to open.

11. Control mechanism for a press or the like according to claim 10 in which the solenoid for each of the second and third switches has an associated movable armature, a member operated by movement of said armature in one direction as a result of energization of said solenoidy for swinging said member about a fulcrum for closing the switch, the'element operating solenoid having an associated movable armature, mechanism operated in response to movement of the last mentioned armature in one direction as 14 a result of deenergization of said element operating solenoid for moving said fulcrum into a position in which it is adapted to be in cooperating relation with said member and for moving said fulcrum out of such position for tripping the switch into open position when said last mentioned armature is moved in the opposite direction as a result of energization of said element operating solenoid upon closure of said switch, said mechanism for swinging said member being operated by movement of the first mentioned armature in the opposite direction as a result of deenergization of the first mentioned solenoid for moving said member into a position in which it is adapted to be in cooperating relation with said fulcrum.

12. Control mechanism for a press or thetlike according to claim 9` in which the operating means for each switch of the pair of switches connected in series comprises a solenoid, while each operator controlled switch is in circuit with a separate one of said solenoids for energizing it when the operator controlled switch is closed, the operator controlled switches each being a fourpole single-throw switch, the terminals of each solenoid being connected to a pair of said poles of the operator controlled switch in circuit with it while the other pair of poles are severally connected to opposite sides of the line for isolating the solenoid from the line when the operator controlled switch is open.

13. Control mechanism for a press or the like according to claim 9 in which the holding circuit also has a normally closed operator controlled switch which when opened interrupts said holding circuit, the holding circuit and the circuits of the separate operating means for the switches of the pair of switches connected in series being connected in parallel across the line.

14. Control mechanism for a press or the like according to claim 9 in which the operating means for each switch of the pair of switches connected in series comprises a solenoid, while each operator controlled switch is in circuit with a separate one of said solenoids for energizing it when the operator controlled switch is closed, the operator controlled switches each being a fourpole single-throw switch, the terminals of each solenoid being connected to a pair of said poles of the operator controlled switch in circuit with it while the other pair of poles are severally connected to opposite sides of the line for isolating the-solenoid from the line when the operator controlled switch is open, the holding circuit also having a normally closed operator controlled switch which when opened interrupts said holding circuit, the holding circuit and the circuits controlled by the first mentioned operator controlled switches being connected in parallel across the line. Y

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