US3069742A - Electric and electronic circuits for controlling friction presses - Google Patents

Description

U. WALCHHUETTER C AND ELEC Dec. 25, 1962 3,069,742 ELECTRI TRONIC CIRCUITS FOR CONTROLLING FRICTION PRESSES 3 Sheets-Sheet l Filed April ll, 1957 Dec. 25, 1962 U. WALCHHUETTER 3,069,742

ELECTRIC AND ELECTRONIC CIRCUITS FOR CONTROLLING FRICTION PRESSES Filed April ll, 1957 5 Sheets-Sheet 2 m wv om N? omw-9-mv ww Inventor um@ wauw@ B7 im@ A v v wv: @MW Si O]- SFNNSS Bmw m SE n 2 d ai 3m. 2: e: A

Dec. 25, 1962 U. WALCHHUETTER C AND ELECTRO ELECTRI NIC CIRCUITS FOR CONTROLLING FRICTION PRESSES 3 Sheets-Sheet 3 Filed April l1, 1957 Inventor: [,Url'w walcklaueferk @7W S. 5w@

3,069,742 ELECTRIC AND ELECTRNS CERCUE'ES FR CONTRLMNS FRECTHIJTJ Ulrico Waichhnethter, Via Spartacio iii, lvi'iian, Italy Filed Apr. 1l, 1957, Ser. No. 652,20i Ciaims priority, application litaiy .italy 2l, i956 5 Claims. (Cl. 25-45} The present invention `relates to electric control systems for friction drive presses. More particularly, the invention relates to a series of improvements introduced to electric and electronic control circuits of friction drive presses.

An object of this invention is to provide who-ily automatic movement of the material carrier or material. transporting carriage by applying an electric current properly synchronized with the operation of the machine so that the forward and `the return movements of said carrier occur only when the press ram of the machine is in its uppermost position, thus avoiding collisions between it and the carrier.

Appropriate means are utilized to ensure a return movement of the carrier when the press is blocked or stopped for reasons that are not related to the carrier.

Another object of this invention is the provision of ydirecting relays acting on the control circuits determining the movements of the press, said relays being capable of selecting switch contacts in circuits that at a given instant are to be operative or non-operative independently of the momentary open or closed position of the particular switches. The capacity of the directing relays therefore permits .the arrangement of said switch contacts so as to ensure the best timing of the movement of the press and consequently a more speedy and reliable operation thereof.

Another object of the invention is the provision of a stopping or blocking system that comprises a relay to be energized each `time when, for any possible reason, the synchronism of the control devices is upset, and particularly in case of interruption of the synchronism between the movements of press and carrier. Blocking or stopping is to be provided also in case the press die or mold, carried by the carrier, does not retake its prescribed position in the press area at the end of the forward stroke or movement of the carrier.

Presses of the type set forth are conventionally equipped with an actuating bar movable from an idle position into positions causing engagement of the friction drive means `for downward and upward movement of the press ram, respectively, and controlled by an electromagnet acting against a return spring.

Another object of this invention is the use o-f means influencing the grid potential of `an electron tube inserted in the circuit of `the magnet that controls through the above-mentioned actuating bar the downward stroke of the press ram, in order to maintain the current constant in said magnet circuit regardless of a variation of the voltage in the feeding power line.

Still another object of this invention is the provision of electronic circuits operating alternatively by influencing the grid potential of the electron tube inserted in the circuit of said magnet, and causing an intensive initial current for energizing the magnet and in this way causing through said actuating bar the displacement of the driving discs of the press into engaging position, and a reduced current for the whole period of time in which the magnet is kept energized.

In accordance with lthe present invention, a combined operating and actuating arrangement for a press includes a Support portion for a workpiece and a press ram and a material carrier. The press ram and the material carnite tats Fate Patented Dec. 25, i952 rier are mounted reciprocably in operating direction from an initial position spaced from the .support portion to an operating position in the region of the support portion and in return direction from operating position to the initial position. The combined operating and actuating arrangement includes ram advancing apparatus for automatically moving the ram in the operating direction toward the support portion, ram return apparatus for automatically moving the ram in the return direction away from the support portion, carrier advancing apparatus for automatically moving the material carrier in the operating direction toward the support portion and carrier return apparatus for automatically moving the material carrier in the return direction away from the support portion. The operating and actuating arrangement includes a ram stopping arrangement associated with the ram advancing apparatus and a carrier stopping arrangement associated with the carrier advancing apparatus, the ram and carrier stopping arrangements being interconnected for automatically interrupting movement in the operating direction of the ram and of the material carrier by the ram advancing apparatus and the carrier advancing apparatus, respectively, when during simultaneous movement in the operating direction of both the ram and the material carrier, the ram reaches a predetermined point of its movement in operating direction after the material carrier has reached another predetermined point of its movement in operating direction. The operating and actuating arrangement further includes an arrangement for automatically actuating the ram return apparatus and the carrier return apparatus for returning the ram and the material carrier respectively .to the respective initial position thereof after movement in the operating direction of the ram and the material carrier has been stopped by the ram and carrier stopping arrangement.

In order that the present invention may be readily carried into effect, it will now be described with reference to the accompanying drawings wherein:

FIG. 1 is a side view of a conventional friction drive press, drawn in dotted lines, in combination with an embodiment of the controlling contacts for the directing relays of the present invention;

FIG. 2 is a schematic diagram of an embodiment of an electric circuit comprising the relays and pertaining contacts, that control the various movements of the press, and including the directing relays and the stopping or blocking relays; and

FIG. 3 is a schematic diagram of an embodiment of a circuit for controlling and regulating the current for the magnet.

Referring now to FIG. l, the yfriction drive press to which are applied the improvements according to this invention comprises two friction discs 1 in spaced location opposite each other and mounted on a common shaft journallcd with axis of rotation 1 in the frame Z of the press itself.

In the space between said two discs l. is rotatably supported by said frame 2 a friction wheel 3, at right angles to the discs l and coupled with a spindle or screw 4 acting on the press ram 5 so that the latter is controlled for its downward and upward movements, respectively depending upon the direction of rotation of said wheel 3.

Discs are displaceable in the longitudinal direction of i the axis l' of their shaft so as to be put into engagement alternatively with one or the opposite side of the wheel 3, in order to rotate said wheel in the respective direction of rotation, depending upon with which one of said discs l the wheel is infrictional engagement, with the purpose of thus causing the upward or downward movement of the press ram 5', respectively. rThe displacement of said spoof/e2 discs l is controlled by metns of an actuating bar (not shown) that through the action of a return spring (not shown) tends to maintain in engagement the one disc for causing an upward stroke of the rain 5. For the do-wnward stroke of the same there is provided a magnet that, by acting upon said actuating bar causes, against the action of said spring, the displacement of the discs in a manner that the other disc l engages the wheel 3 and thus causes rotation of said wheel in the opposite direction.

The rain 5 is thus mounted reciprocably in operating direction from an initial position spaced from the support portion for a workpiece at the base of the apparatus to an operating position in the region of the support portion and in return direction from the operating position to the initial position. The ram 5 is automatically moved by the discs l and wheel 3 in the operating direction toward the support portion and in the return direction away from the support portion.

Mounted for vertical movement jointly with screw 4' of the press is a control bar 4 that is carried by the arm 5.

The control bar 4 controls by means of an attached earn 6 four contacts l, la, ll, lla. The control bar 4 controls by means of a second cam 7, which is displaceable for a predetermined limited distance along said control bar, the opening and closing of a contact Cs. When the cam '7 moves downward with the control bar 4, said cam opens the contact Cs and when said cam moves upward with said control bar, the said cam closes said con tact.

The control mechanism comprising the contacts I, In,

ll, lla and Cs, and the control bar 4 are mounted, as shown in FlG. l, in proximity to the press to enable vertical movement of the screw il and therefore vertical movement of the press ram 5 to produce vertical movement of said control bar in the corresponding direction.

The closing and opening of contacts Cs caused by the cam 7 serves to close or respectively to open the circuit of a sensing relay RS in order to place the circuits of said contacts I, la, Il, lla into operative or non-operative condition, respectively, for the hereinafter explained reason, and in order to control stopping or blocking circuits described below.

'l'he function and operation of the abovedescribed arrangement will be explained with reference to FlGS. l and 2.

ln the diagram of FIG. 2, the coils of the individual relays are indicated by circles with a reference symbol like Rl, RS, RL-li, lll-2, etc. inscribed. The switch contacts operated by the individual relay coils are shown, for the sake of clarity of the diagram, separated from the coils, and in normal position, marked with reference symbols containing the symbol of the pertaining relay plus an added numeral indicating that the particular contact is the iirst, second, etc., contact of that relay, eg. llRl-ll, ZELL Sill-l. lf no numeral is added to the contact reference symbol, then the relay reference symbol marking a Contact indicates that it is the only Contact of the particular relay.

As shown, contacts l, la, ll, llo are connected in circuit with directing relays Ril-ll, Rll-2 and Rl-S, respectively, and control, through the relays Rl-l, Ril-2, and lll-3, the actuating relay Rl-l. Contact Cs controls the circuit of a sensing relay RS which, when energized, operates through a plurality of contacts lRS, ZRS, SRS the circuits directing relays Rit-l, Rl-Z and Ril-3 in the following manner.

Supposing the press is Working, and therefore the main switch TL (FGURE 3) is in closed position, whereby contact tTL is opened and a blocking relay Rb is thus not energized (FIG. 2) and a starting relay Rl is enen gized via closed Contact ZRb so as to hold contact lill closed, and supposing the press is terminating the last portion of its upward movement so that cam 7 is carried upward by the collar 7 fixed to bar 4 and causes contact Cs to close, whereby relay RS is energized and contacts lRS, ZRS and QRS are closed, the following situation eX-v rl`he cam 6 also moving upwardly causes the closure of contact l, so that Contact ZRS being closed, the di-A recting relay Rl-l is energized. The relay Rl-l thenv closes the contacts lRl-ll and SRL, and opens contact' QLRt-l. Contact ltRl-il closes the circuit of the actuating relay Rl-l, which, upon being energized, moves contacts A1 and Bl of the electronic circuit (FlG. 3), thus causing the closure o-f the circuit of the electromagnet mentioned above. The magnet, upon being energized, causes, as described, the displacement of the discs 1 for causing downward movement of the ram 5. Simultaneously with the ram, the control bar 4 moves downwardly and with it cam 7 so as to cause the opening of contact Cs, thus interrupting the energization of relay RS whereby contacts ERS and lRS are again opened, while relay 'Rl-l remains energized due to the holding circuit estab-f lished by the still closed contact la and the contact ZRl-l. 'Participating in the downward movement of the press ram 5', control bar d, through cam 6, causes the opening of contact la, thereby deenergizing relay Iii-l. Consequently, contact SRl-l opens, contact 2R11 is closed again, and contact lRl-l is opened, thus interrupting the energization of actuating relay R143, and thereby causing the interruption of the magnet circuit at A1 and Bl (FlG. 3).

Since the magnet 8 is then deenergized, the abovementioned return spring can move the actuating bar so as to move the discs 1 in opposite direction for causing an engagement of the friction drive for the upward stroke of the ram 5. Notwithstanding this situation, the press, although under a braking effect between the friction drive' members, continues by inertia and weight its downward movement until a first compression is effected in the mold, while cam 6 during this continued movement operates, or closes, the contacts IIa and H, although without any effect due to the contacts ZRS and SR1-2 being open. Thus, the press ram 5', after having causedv said lirst compression, and having consumed the downward directed force of inertia, will be moved upwards. Thus, rst Csi is closed by the upward movement of cam 7 and accordingly relay RS is energized to close Contact IRS (but without any effect, because contact SR1-1 is open) and contact ZRS will close. During the continuation o-f the upward movement of ram 5', cam 6, which had reached a position 6', closes the contact II that can now close the energization circuit of relay Rit-2, which circuit also includes a con-tact ItR-S, which, however, is closed.

Relay lll-2 closes the contact lRl-Z obtaining a holding current as well as contact ZRl-Z (for energizing the actuating relay R-d) `and also closes contact 3111-2. Through this energization of relay R1-4 the magnet 8 (FIG. 3) is energized so that the friction discs are again displaced for causing engagement of the friction drive for the downward stroke of the ram 5. The ram is thereby reversed to downward movement. During this movement, Cs is opened by cam 7 and relay RS is deenergized again so as to close Contact SRS. During this second downward movement of the ram 5 contact lla is closed so as to cause energization of relay Rl-, that is held energized through closed contact 2Rl-3, and opens lill-3 thus interrupting the energization of relay Rit-2 and causing therefore the opening of contact ZRl-Z (besides causing the other contacts of relay Rl-Z to open). This results in the interruption of the energization of actuating relay Rit-4l so that the magnet circuit is cut off and the press ram 5 is reversed to upward movement. The upward movement of the prees ram 5 does not cause any action due to the operation of contact lla, because contacts SRl-Z and SRS are open, nor any action due to operation of contact Il, because contact llRlis open, since relay Rl-3 is still energized. "t" he relay Rl-S has also closed contact ltRlwhich is connected in circuit with contact RS (that is closed due to cam 7 being in its upper position because the ram 5 is in its upward species movement) and also with contact llRb, that is also closed, so that the carrier or carriage relay Rc may be energized by closing contact lbs, as will be explained more in detail hereinafter.

As shown, the provision of the sensing relay RS greatly simplifies the circuit, since it controls alternatively during upward or downward movement of the press ram 5' the circuits of the directing relays Rl-l, Rl-Z and Rl-S. Furthermore, the sensing relay RS permits mutually independent positioning of said contacts l, Ia, II and Ila. In particular, contact lla can be positioned at the same level or even above contact ll (as shown in FIG. 1), and the same can be done with contacts I and la, in order to best utilize the inertia of the press ram 5, without in any way affecting the principle of its operation.

lt is to be noted that relay Rl-S at the termination of the downward movement of the press ram 5 has caused the closure of contact 3R1-3, thus permitting contact lbs to close the circuit of the carrier or carriage relay Rc. Contact libs together with contact Zbs constitute a double contact bs which is controlled by the rod 9 (FlG. l). The rod 9 is operatively connected with movable parts of the mold or press and is therefore lifted after every pressing operation, by means of a mechanical device controlled by the press itself, for the purpose of electing the molded or pressed product. The rod 9 stoves the double Contact bs by means of a projection or ring it) to its closed position during its upward stroke, and opens said double Contact when it moves down to its low position.

The closure of contact lbs causes therefore the energization of the carrier or carriage relay Rc so as to close Contact lRc, for holding the relay energized, and Contact ERC, thus closing the circuit of the relay TF. The relay TSF, when energized, closes Contact lTF, thereby energizing coil .l5 of an electromagnetic friction coupling means il (FIGS. l, 2 and 3) disposed on shaft 12 of a motor 13 which uninterruptedly rotates, and the purpose of which is to impart a forward movement to the carrier or carriage M (FlG. 1) through a suitable crank device (not shown). The forward movement of the carrier or carriage 14 is controlled by cam 16, rotated in coordination with said movement, and which is provided with a recess or step in order to permit the return of the second double Contact bc to the position shown in FlG. l which, in this normal position will maintain contact bc closed. When the contact tbc is closed, the carrier relay Rc holds itself in energized condition, the contact 2bn being also maintained thereby in open position (FiG. 2). As soon as cam lo beUins to rotate, the second double contact bc is moved so that contact 2bn will close, thus feeding current to relay TF, while contact bc opens in order to deenergize the carrier relay Rc. Deenergization of the carrier relay Rc causes contacts lRc and ZRc to open, while the holding current through the relay TF maintains the connection for a whole turn of cam lo, corresponding to a full cycle of movement of the carrier, i.e. for its forward and return stroke. The material carrier l@ is thus automatically reciprocably moved in the operating direction from an initial position spaced from the support portion at the base of the apparatus to an operating position in the region of the support portion and in the return direction from the operating position to the initial position, said carrier moving toward the support portion in the operating direction and away from said support portion in the return direction. Contact Zbc therefore ensures the return of said carrier, even when, for whatever reason, the press is stopped, or when all other circuits are interrupted.

At the termination of a complete rotation of cam 16, contact bc will move back to normal position, opening contact Zbc and therefore, by interrupting the energizetion of relay TF, contact bc causes contact lTF to open and to deenergize the circuit of coil l5 so as to disengage the friction coupling means ll and to stop the carrier 14 d in its full return position. At the same time, contact lbc is closed again without any effect on the carrier relay Rc, Contact lRc being open. From the preceding description, it is evident that the automatic movement of the carrier is controlled in a remarkably simple, yet reliable manner.

A further feature of this invention is the provision of a stopping or blocking relay Rb for manually stopping the press at will, by pressing down, or closing, a suitable switch button. rhe blocking or stopping relay Rb will also stop the press automatically when the carrier or the mold are in danger of being crushed by the press ram. Relay Rb is energized by contact lTL (FIGS. 2 and 3) which is closed when switch TL is open. When the press is put in operation and TL is closed, said contact TL is open so that the stopping or blocking relay Rb may be deenergized by manual operation of a button Mc to open contact lMc, whereby relay Rb is disconnected even if contact Rb, in series therewith, should be closed tending to hold relay Rb in energized condition. Relay Rb can then be energized at any time by pressing a stop switch button Pa in order to block or stop the press at will, due to the fact that stop switch button Pa actuates contact lPa together with contact ZPa for energizing; the relay Rb and simultaneously disconnecting the starting relay Rl. An automatic energization of stopping relay Rb occurs in two particular cases in which contact 2bs is closed. The first case occurs when rod 9 and double contact bs (FIG. l) are not moved to normal position after the press ram 5 has completed its upward stroke or when the mold does not return to normal condition after the ejection of a molded object, in which case contact Zbs which was closed at the beginning of the downward stroke of the ram, would be left in closed position. At the same time, relay RS, due to closing of contact Cs during the downward stroke, closes Contact SRS. Contacts Zbs and SRS, connected in series, in the abovementioned case, close the circuit of stopping relay Rb, thereby energizing it with the effect of stopping the press as described below.

The second case of automatically stopping the press occurs when the feeding `of the powdered material to be pressed is not uniform or is insuflicient, so that the press ram 5 moves downward in operating direction during the pressing operation to an excessive extent, beyond the predetermined level, and the space (or thickness of compressed material) between the upper press member of the press die and the bottom of the mold would be unduly reduced. Thus, in order to avoid damaging the mold cavity, and also in order to ensure uniformity of the product in the aforesaid eventuality, the press is provided with a limit contact bt, (FIGS. 1 and 2) which is actuated and closed by the press ram 5' when its stroke is excessive, so that the stopping relay Rb is energized and then remains closed through holding current provided by the closing of the Contact 3Rb connected in series with the now closed control contact lvl'c. Whatever may be the cause of energization of relay Rb, it will move both contacts lRb and ZR!) to open position. Contact ZRb opens the circuits of the relays Rl, RS, Rl-l, 'Rl-2, R-E': and Rit-4, so that by the interruption of the circuit of magnet 8 (FlG. 3) a downward stroke of the ram is prevented or stopped. Contact lRb is opened and causes thereby interruption of the energization of the carrier relay Re so that in case that the carrier relay should have been in energized condition the contacts lRc and tlc would be opened. ln any case, the carrier lit being in motion and contact Zbc therefore being closed, the carrier will continue its movement until it reaches the end of its return travel in which moment cam 16 returns to normal position and contact Zbc opens again. Thus, whatever should be the instant when the: press ram is stopped, contact Zbc assures that the carrier i4 will continue its movement until it reaches the position that corresponds to the idle condition of the press, whereby the carrier is protected against any damage.

A subsequent starting of the carrier 14 is not possible in such situation because of the fact that the now open contact 1R15 (stopping relay Rb being energized) prevents the energization of the carrier relay Rc and consequently any operation of the carrier 14 is prevented. ln order to restart the operation of the press, it is necessary to interrupt the energization of stopping relay Rb by pressing down the control button Mc, the contact 1Mo of which opens and thus interrupts the holding circuit f relay Rb, while at the same time the contact 2Mc closes the circuit for carriage relay Rc and thus provides for the start of operation of the carrier 14. Thereafter, it is possible to start the press again, by pressing down both the buttons Pc connected in series (for safe two-hand operation) and thereby energizing the starting relay Rl which holds itself energized through the holding contact ZRI and the stop switch contact ZPa.

Another feature of this invention is the provision of a device for the regulation of the current in the circuit of the actuating magnet 8. Referring to FIG. 3, which is to be understood to be an extension of the circuit arrangement of FIG. 2, the line ends x, y of FIG. 3 being con nected with the line ends x, y, respectively, of FIG. 2, there is provided in the electric power line L a main switch TL. The switch TL permits the energization of the carrier drive motor 13, and permits the energization of the electromagnet 8 through the secondary switch TL, via a transformer T1. A single phase portion of the electric line power is used for feeding all the devices operating on direct current. To this end, a transformer T4 is fed with A C. in order to feed D.C. through the circuit x, x/y, y to the relay by means of a rectifier RAS. A seco-nd transformer T3, which is provided with two secondary windings, feeds two circuits A and i3. Connected in the circuits A and B are respectively the rectitiers RA1 and RAZ, at the output of which the current is smoothed by the condensers C1 and C2, respectively, in order to properly feed the discharge tubes V2 and Vd, which cause a constant voltage drop. A potentiometer Pi is connected in series with tube V4 for adjusting the operating voltage between terminal 17 and the terminal 1S of contact A1 of relay R1-4 mentioned above. The voltage taken from potentiometer P1 is further reduced by a potentiometer P3, to the sliding tapping point of which terminal 18 of contact A1 is connected.

In the deenergized position of relay R1-4 (FIG. 2), contacts A1 and B1 are positioned as shown in FIG. 3, and the grid of tube V1 of the magnet circuit remains biased with negative voltage as determined by the potentiometer P3 and supplied by the circuit A that is made t stable by the discharge tube V4. In this condition of the arrangement, there is no current in the circuit of the magnet 8, due to the opposing potential of the grid of tube V1. Upon energization of actuating relay .R1-4, contacts A1 and B1 are removed to a second position. Contact A1 disconnects the circuit A from the cathode of tube V1 in favor of the circuit B that suppiies a posi* tive voltage at terminal i8 which opposes that supplied by the circuit A. The voltage supplied by circuit B via the connection 13, 17 is now less negative than that supplied before by the circuit A or even positive, so that at the grid of tube V1 there is applied a voltage that is suiiciently more positive to ensure the maximum conductivity of tube V1. So in this first phase of operation, there is available instantaneously in the circuit of tue magnet coil 8 as intensive a current as is required to produce in the magnet the necessary force for attracting and operating the actuating bar.

Contact B1, which is also operated by the coil of actuating relay lll-4, connects, when moved from the shown position of rest into its second position, in the circuit B the condenser CL which is charged within a period of time that depends upon the positioning of potentiometer P2, thereby reaching after a certain delay a potential that is suiiicient to render the tube V conductive; the tube V5 having been connected'in the enode cathode circuit of tube V1 by contact Bi in its second position. The tube V5 provides for the iiow of current in resistance R1 thereby causing a voltage drop that reduces the voltage originally supplied by circuit B, so that the voltage that results from the series-connection of the circuits A and B becomes zero or even negative to a certain degree. The reduced voltage is applied as bias to the grid of tube V1, and may finally oe adjusted to a desired value through the po` tentiometer P3. At this point, therefore, the current in the circuit of the magnet S diminishes, and remains the same until the contacts A1 and B1 return to the normal position as shown. At the moment when the contacts A1 and B1 return to their normal position, the condenser CL discharges across resistance R2. ri`he above described circuit not only regulates the magnet current, but also serves in accordance with the invention to control the constancy of the current in the circuit that comprises magnet coil 8, tube V1 and transformer T1, by adjusting the voltage supplied by the power line at L. in fact, when a variation or fluctuation of the line voltage occurs, the potentiometer P1 will cause a variation of voltage in proportion with that occurring in the power line. The sliding tapping point of the potentiometer P1 transmits in this way to potentiometer P3 a varying voltage, so that, when A1 is switched to connect the output of the circuits A and B in series, the difference between the voltages supplied by circuits A and B, after the tube VS has become conductive, will result in causing the potential of the grid relative to the cathode of tube V1, to become almost zero or slightly negative, as hereinabove explained. supposing that the voltage of the network drops, then a proportional drop of voltage will occur across the potentiometer P1. This reduction of voltage across potentiometer P1 will reduce the negative voltage at 17 so that the positive voltage supplied by circuit B at 18 is counteracted to a lesser degree and a positive voltage is applied to the grid of tube V1, thus establishing in the circuit T1, V1, 8 the normal operating conditions that prevailed at normal line voltage, i.e. before said drop thereof. Of course, in the case of an increase of the line voltage the positive potential from circuit B will be more effectively overcome by the negative bias voltage furnished by circuit A and therefore the bias voltage of the grid will vary by becoming more negative and thus diminish the conductivity of V1, and thus again keep the voltage applied to the magnet coil 8 at the desired constant level.

Of course, the a-bove-mentioned improvements may also -be realized in a diiferent manner than that hereinabove described, by a modification of the electric circuits described in detail, without departing from the gist and scope of this invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adept it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspect of this invention and, therefore, such adaptations should and are intended to be comprehended within the mea-ning and range of equivalence of the following claims.

What is claimed as new and desired to be secured by Letters Patent is:

l. A combined operating and actuating arrangement for a press including a support portion for a workpiece, press ram means and material-carrier means, each of said press ram means and said material-carrier means being mounted reciprocabiy in operating direction from an initial position spaced from said support portion to an operating position and in return direction from said operating position to said initial position in the region of said support portion said combined operating and actuating arrangement including ram advancing means for automatically moving said adegua ram means along a ram path in said operating direction toward said support portion;

ram return means for automatically moving said ram means along said ram path in said return direction away from said support portion;

carrier advancing means for automatically moving said material-carrier means along a carrier path in said operating direction toward said support portion;

carrier return means for automatically moving said material-carrier means along said carrier path in said return direction away from said support portion;

ram stopping means associated with the ram advancing means for stopping upon operation advancing movement of said ram advancing means;

carrier stopping means associated with the carrier advancing means for stopping upon operation advancing movement of said carrier advancing means;

first actuating means constructed so as to be actuated automatically when said material-carrier means passes beyond a predetermined point during its movement in operating direction along said carrier path;

second actuating means constructed so as to be actuated automatically when said ram means passes beyond a predetermined point during its movement in operating direction along said ram path; and

operating means associated with said first and second actuating means and adapted to operate said ram stopping means and said carrier stopping means simultaneously the moment said ram means passes during its movement in operating direction said predetermined point of said ram path after said material-carrier means passes during its movement said predetermined point of said carrier path so as to stop advance movement of both ram means and said material-carrier means when after passing of said material-carrier means along said carrier path lbeyond said predetermined point thereof said ram means passes along said ram path beyond said pre- :determined point thereof.

2. A combined operating and actuating arrangement 'ifor a press including a support portion for a workpiece,

press ram means and material-carrier means, each of jsaid press ram means and said material-carrier means tuating arrangement including ram advancing means for automatically moving said ram means along a ram path in said operating direction toward said support portion;

ram return means for automatically moving said ram means along said ram path in said return direction away from said support portion;

carrier advancing means for automatically moving said material-carrier means along a carrier path in said operating direction toward said support portion;

carrier return means for automatically moving said material-carrier means along said carrier path in said return direction away from said support portion;

ram stopping means associated with the ram advancing means for stopping upon operation advancing movement of said ram advancing means;

carrier stopping means associated with the carrier advancing means for stopping upon operation advancing movement of said carrier advancing means;

rst actuating means constructed so as to be actuated automatically when said material-carrier means passes beyond a predetermined point during its move ment in operating direction along said carrier path;

second actuating means constructed so as to be actu- Y ated automatically when said ram means passes beyond a predetermined point during its movement in operating direction along said ram path;

operating means associated with said tirst and second actuating means and adapted to operate said ram stopping means and said carrier blocking means simultaneously the moment said ram means passes during its movement in operating direction said predetermined point of said ram path after said material-carrier means passes during its movement said predetermined point of said carrier path so as to stop advance movement of both said ram means and said material-carrier means when after passing of said material carrier means along said carrier path beyond said predetermined point thereof said ram means passes along said ram path beyond said predetermined point thereof; and

means for automatically operating said ram return means and said carrier-return means after operation of said ram stopping means and said carrier stopping means.

3. A combined operating and actuating arrangement for a press including a support portion for a workpiece, press ram means and material-carrier means, each of said press ram means and said material-carrier means being mounted reciprocably in operating direction from an initial position spaced from said support portion to an operating position in the region of said support portion and in return direction from said operating position to said initial position, said combined operating and actuating arrangement including electrically energized driving means for driving said ram means;

electrical supply means for electrically energizing said driving means;

ram advancing means for automatically moving said ram means along a ram path in said operating direction toward said support portion;

a ram return means for automatically moving said ram means along said ram path in said return direction away from said support portion;

carrier advancing means for automatica ly moving said material-carrier means along a carrier path in said operating direction toward said support portion;

carrier return means for automatically moving said material-carrier means along said carrier path in said return direction away from said support portion;

ram stopping means associated with the ram advancing means for stopping upon operation advancing movement of said ram advancing means;

carrier stopping means associated with the carrier advancing means for stopping upon operation advancing movement of said carrier advancing means;

first actuating means constructed so as to be actuated automatically when said material-carrier means passes beyond a predetermined point during its movement in operating direction along said carrier path;

second actuating means constructed so as to be actuated automatically when said ram means passes beyond a predetermined point during its movement in operating direction along said ram path;

operating means associated with said first and second actuating means and adapted to operate said ram stopping means and said carrier stopping means si muitaneously the moment said ram means passes during its movement in operating direction said predetermined point of said ram path after said material-carrier means passes during its movement said predetermined point of said carrier path so as to stop advance movement of both said ram means and said material-carrier means when after passing of said material-carrier means along said carrier path beyond said predetermined point thereof said ram means passes along said ram path beyond said predetermined point thereof;

11 means for automatically operating said ram return means and said carrier return means after operation of said ram stopping means and said carrier stopping means; and

electrical control means interposed between said driving means and said electrical supply means for proiding an initial energizing current of sufficient magnitude to start actuation of said driving means for driving said ram means in operating direction and for reducing the energizing current after actuation of said driving means to a substantially lower magnitude suicient to maintain actuation of said driving means.

4. A combined operating and actuating arrangement for a press including a support portion for a workpiece, press ram means and material-carrier means, each of said press ram means and said material-carrier means being mounted reciprocably in operating direction from an initial position spaced from said support portion to an operating position in the region of said support portion and in return direction from said oeprating position to said initial position, said combined operating and actuating arrangement including electrically energized driving means for driving said ram means;

electrical supplying means for electrically energizing said driving means;

ram advancing means for automatically moving said ram means along a ram path in said operating direc tion toward said support portion;

ram return means for automa 'cally moving said ram means along said ram path in said return direction away from said support portion; carrier advancing means for automatically moving said material-carrier means along a carrier path in said operating direction toward said support portion;

carrier return means for automatically moving said material-carrier means along said carrier path in said return direction away from said support portion;

ram stopping means associated with the ram advincing means for stopping upon operation advancing movement of said ram advancing means; carrier stopping means associated with the carrier ad vancing means for stopping upon operation advancing movement of said carrier advancing means;

iirst actuating means constructed so as to be actuated automatically when said material-carrier means passes beyond a predetermined point during its movement in operating direction along said carrier path;

second actuating means constructed so as to be actuated automatically when said ram means passes beyond a predetermined point during its movement in operating direction along said ram path; operating means associated with said first and second actuating means and adapted to operate said ram stopping means and said carrier stopping means simultaneously the moment said ram means passes during its movement in operating direction said predetermined point of said ram path after said material-carrier means passes during its movement said predetermined point of said carrier path so as to stop advance movement of both said ram means and said material-carrier means when after passing of said material-carrier means along said carrier path beyond said predetermined point thereof said ram means passes along said ram path beyond said predetermined point thereof, said operating means comprising control circuit means energized by said electrical supply means, a plurality of relay switch means connected in said control circuit means and sensing relay switch means connected in said control circuit means with said relay switch means for controlling the energization of selected ones of said relay switch means in accordance with the energizaf l1.2 tion of said sensing relay switch means, said rst and second actuating means comprising a plurality of control contact switch means mounted in proximity to said ram means andconnected in said control circuit means with said relay switch means in a manner whereby said control contact switch means control the energization of selected ones of said relay switch means, direction-sensitive switch means mounted in proximity to said ram means and connected in said control circuit means with said sensing relay switch means in a manner whereby said direction-sensitive switch means controls the energization of said sensing relay switch means, and switch control means for controlling the operation of said control contact switch means and said direction-sensitive switch means in accordance with the movement of said ram means; means for automatically operating said ram return means and said carrier return means after operation of said ram stopping means and said carrier stopping means; and i electrical control means interposed between said driving means and said electrical supply means for providing an initial energizing current of sui'licient magnitude to start actuation of said driving means for driving said ram means in operating direction and for reducing the energizing current after actuation of said driving means to a substantially lower magnitude sufficient to maintain actuation of said driving means.

5. A combined operatingvand actuating karrangement for a press including a support portion for a workpiece, press ram means and material-carrier means, each of said press ram means and said material-carrier means being mounted reciprocably in operating direction from an initial position spaced from said support portion to an 0perating position in the region of said support portion and in return direction from said operating position to said initial position, said combined operating and actuating arrangement including electrically energized driving means for driving said ram means;

electrical supply means for electrically energizing said driving means;

ram advancing means for automatically moving said ram means along a ram path in said operating direction toward said support portion;

ram return means for automatically moving said ram means along said ram path in said return direction away from said support portion; carrier advancing means for automatically moving said material-carrier means along a carrier path in said operating `direction toward said ysupport portion;

carrier return means for automatically moving said material-carrier means along said carrier path in said return direction away from said support portion;

ram stopping means associated with the ram advancing means for stopping upon operation advancing movement of said ram advancing means; carrier stopping means associated with the carrier advancing means for stopping upon operation advancing movement of said carrier advancing means;

first actuating means constructed so as to be actuated automatically when said material-carrier means passes beyond a predetermined point during its movement in operating direction along said carrier path;

second actuating means constructed so as to be actuated automatically when said ram means passes beyond a predetermined point during its movement in operating direction along said ram path; operating means associated with said rst and second actuating means and adapted to operate said ram stopping means and said carrier stopping means simultaneously the moment said ram means passes during its movement in operating direction said predetermined point of said ram path after said material-carrier means passes during its movement said predetermined point of said carrier path so as to stop advance movement of both said ram means and said material-carrier means when after passing of said material-carrier means along said carrier path beyond said predetermined point thereof said ram means passes along said ram path beyond said predetermined point thereof, said operating means comprising control circuit means energized by said electrical supply means, a plurality of relay switch means connected in said control circuit means and sensing relay switch means connected in said control circuit means with said relay switch means for selectively rendering selected ones of said relay switch means operable and for selectively rendering selected ones of said relay switch means inoperable in accordance with the energization of said sensing relay switch means, said lirst and second actuating means comprising a plurality of control contact switch means mounted in proximity to said ram means and connected in said control circuit means in a manner whereby saidcontrol Contact switch means control the operation of selected ones of said relay switch means, said control contact switch means being adapted to be opened and closed to respectively open and close corresponding ones of said relay switch means, direction-sensitive switch means mounted in proximity to said ram means and connected in said control circuit means with said sensing relay switch means in a manner whereby said direction-sensitive switch means controls the operation of said sensing relay switch means, said direction-sensitive, switch means being adapted to be opened and closed t respectively deenergize and energize said sensing relay switch means, and switch control means for controlling the operation of said control contact switch means and said direction-sensitive switch means in accordance with the movement of said ram means,

ifi-

said switch control means comprising a control member carried by said ram means and positioned in operative proximity to said control contact switch means and to said direction-sensitive switch means in a manner whereby said control member opens and closes selected ones of said control contact switch means and thereby opens and closes the correspondY ing relay switch means connected in said control circuit means with said control contact switch means in correspondence with the movement of said ram means through a plurality of positions during reciprocation thereof and whereby said control member opens said direction-sensitive switch means thereby deenergizing said sensitive relay switch means in correspondence with the movement of said ram means in operating direction and closes said direction-sensitive switch means thereby energizing said sensing relay switch means in correspondence with the movement of said ram means in return direction;

means for automatically operating said ram return means and said carrier return means after operation of said ram stopping means and said carrier stopping means; and

electrical control means interposed between said driving means and said electrical supply means for providing an initial energizing current of sucient magnitude to start actuation of said driving means for driving said ram means in operating direction and for reducing the energizing current atter actuation of said driving means to a substantially lower magnitude suicient to maintain actuation of said driving means.

References Cited in the le of this patent UNITED STATES PATENTS 2,674,008 Van der Pyl Apr. 6, 1954 2,712,168 Kenline July 5, 1955 2,770,862 Miller Nov. 20, 1956 2,803,852 Cook Aug. 27, 1957 2,923,973 Winneman Feb. 9, 1960

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