US 3678725 A
Container forming press comprised of a combined punch, drawing die, and stripper means for effecting the formation of and ejection of a container from the press during a full cycling of the same. The press further includes an improved electrofluidic control system connected to the punch and drawing die means which operates to detect malformed containers and to stop the apparatus so that the malformed containers can be removed.
Claims available in
Description (OCR text may contain errors)
United States Patent Langewis 15 3,678,725 July 25, 1972 CONTAINER FORMING APPARATUS 72] Inventor: Cornelis Langewis, Walnut Creek, Calif.
 Assignee: Kaiser Aluminum 8; Chemical Corporation, Oakland, Calif.
 Filed: Oct. 19, 1970  Appl.No.: 81,854
52 user. ..12/344, 72/348 511 Int.Cl ..B2ld45/00  FieldofSearch ..72/349,36l,348,344
 References Cited UNITED STATES PATENTS 3,312,098 4/1967 Henrickson etal 3,338,997 8/1967 Tigner ...72/345 2,901,995 9/1959 Lavigne ..72/344 601,738 4/1898 Stampacchia ..1 13/120 Wintriss ..72/36l FOREIGN PATENTS OR APPLlCATlONS 531,213 12/1940 Great Britain ..72/28 Primary E.\'aminer-Richard J. Herbst Attorney-James E. Toomey. Paul E. Calrow. Harold L. Jenkins and John S. Rhoades  ABSTRACT Container forming press comprised. of a combined punch, drawing die, and stripper means for effecting the formation of and ejection of a container from the press during a full cycling of the same. The press further includes an improved electrofluidic control system connected to the punch and drawing die means which operates to detect malformed containers and to stop the apparatus so that the malfonned containers can be removed.
13 Claims, 8 Drawing Figures ELECTED FL lI/DIC C 0N T 30L 3 YSTE M Patented July 25, 1972 4 Sheets-Sheet 1 TEN CUBA/EL [6 L ANGEWl-S IAIVEA/TOR By A T TOE/V5 Y Patented July 25, 1972 4 Sheets-Sheet 2 COR/VEL/S LANGE w/s nvunvroe B y 90 w QM ATTORNE Patented July 25, 1972 4 Sheets-Sheet 4 m a. g
CONTAINERFORMING APPARATUS BACKGROUND OF THE INVENTION This invention relates to a press apparatus for drawing a workpiece into a container. More particularly, it relates to a fast acting press apparatus which operates to draw and reverse draw a workpiece into a container together with a control system which includes improved means for stopping the apparatus if a malformed workpiece is detected.
Various prior art draw and reverse draw apparatus used to form a workpiece into a container have involved the usual series of interrelated platens and punch and die assemblies for forming a workpiece into a container. In some instances, the
punch of the punch and die assembly of a press has been provided with an internal fluid passageway for use in holding or discharging a workpiece relative to the punch during operation of the apparatus. None of the prior art apparatus, however, contemplated utilizing the fluid passageways of a punch in combination with a novel electrofluidic sensing means to detect malformed containers. Examples of typical prior art apparatus for drawing and reverse drawing the workpiece into a container are exemplified by US. Pat. No. 2,602,411 to Schnell, granted June 8, 1952; US Pat. No. 2,901,995 to Lavigne, granted Sept. 1, 1959; and US. Pat. No. 3,312,098 to Henrickson et at, granted Apr. 4, 1967.
SUMMARY OF THE INSTANT INVENTION It is the primary purpose of the instant invention .to provide an improved press apparatus for producing single or multiple containers during a full operating cycle of the press from metal coil stock incrementally advanced or fed to the press. The press is provided with a punch and die assembly advantageously equipped with the unique and exceptionally sensitive electrofluidic control system of the invention to detect malformed containers. The control system operates smoothly without'interfering with the nonnal continuous cycling of the punch and die assembly and acts to stop the apparatus at a predetermined point substantially as soon as a malformed container is detected.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmentary end elevational and somewhat diagrammatic view with parts broken away of a preferred embodiment of the press apparatus and control system of the instant invention;
FIG. 2 is an enlarged partial sectional view with parts added when taken along line 2-2 of FIG. 1;
FIG. 3 is a schematic view of a preferred embodiment of an electrofluidic control system that can be used with the apparatus of FIG. 1;
FIG. 4 is a perspective view taken in the area of reference line 4-4 of FIG. 2 and with parts added;
FIGS. 5-7 comprise a series of enlarged fragmentary elevational and somewhat diagrammatic views of the press punch of the instant invention and illustrate various operative positions of the punch during a full operative cycle of the press, with these various operative positions being cross-indexed with the graph illustrated in FIG. 8; and
FIG. 8 is a graphic depiction of certain operating positions assumed by a punch of the press of the instant invention during a full operating cycle of the press.
DETAILED DESCRIPTION With reference to the drawings, a preferred embodiment of the press 10 of the instant invention is shown together with the unique electrofluidic control system 11 therefor. Although the press apparatus to be described is shown as having a plurality of punches, e.g., four, whereby four blanks can be simultaneously drawn and then reversely drawn into containers C from a length of aluminum coil stock, the press could be provided with a single punch if desired. During the initial part of each operating cycle, the press 10 acts to simultaneously sever or blank out four flat metal disc-shaped blanks from a length of sheet metal stock S fed incrementally to the press. These four severed blanks are progressively drawn and redrawn into four cup-shaped containers C and then finally ejected from the press. Since each of the four containers will usually have the same shape, only one such container C is shown in any detail throughout the drawings.
The apparatus is generally comprised of a heavy duty framework 12, a stationary platen 14 connected thereto and a plurality of three movable platens 15-17. As will be more fully set forth hereinafter, each of the platens 15-17 is separately connected to and driven by a common cam drive shaft 23' so that platens 15-17 can move relative to each other in directions toward and away from fixed platen 14 during the drawing and reverse drawing of a workpiece into a container. As indicated in FIGS. 1-2 and 5-7, movable platen 15 is preferably disposed immediately above the top or open face of fixed platen 14 while the movable platens 16-17 are preferably disposed on each side of movable platen 15 in the manner shown in FIGS. 1-2 and 5-8.
Operatively affixed to and associated with platens 14-17 is a plurality of laterally spaced, punch and die assemblies 19. The punch and die assemblies 19 include improved means for stripping and ejecting containers therefrom in a manner whereby there is no serious disturbance or interference with the normal cycling of the press 10.
As graphically illustrated in FIG. 8,. control system 11 detects or senses the presence of a properly formed or malformed container C at a prechosen point P of a given operative cycle of the press. If a malformed container is detected at the prechosen point P, on the graph, the control system immediately functions to stop the apparatus such as at a subsequent predeterrnined point P in the same or next operative cycle. Stoppage of the press during an operative cycle occurs at the point where the operator will have ready access to the die assembly for the purpose of removing the defective container.
The cup-shaped container formed by the press in the instant invention can be further redrawn and ironed in a draw and ironing press or the wall of the container can be merely ironed in an ironing press. A detailed description of the press and the control system 11 will now be given.
Framework 12 can be made up of a plurality of welded plate elements of various types and sizes symmetrically arranged about the central axis 20 of the press 10. As regards FIG. 1, it is to be understood that the righthand part of the press, although not shown in the drawing and unless otherwise specified, is substantially identical to that shown on the lefthand side of axis 20. Top plate 21 of framework 12 is provided with a plurality of upwardly projecting spaced bosses 22. A drive shaft 23 is inserted through aligned openings in bosses 22 and journalled in the bosses. An air operated brake and clutch device 24 is connected to one end of shaft 23' and flywheel 23 mounted on the shaft 23 is connected to the output shaft and pulley assembly 26 of motor M by a conventional drive belt 25. Motor M is suitably mounted in the base of framework 12.
The bottom platen 14 is appropriately anchored to the base of the framework and at the same time rigidly connected to framework top plate 21 by way of a box-like support 25', a corner portion of which is shown in FIG. 1.
In an advantageous embodiment of the invention, movable platen 15 is advantageously cam-connected to drive shaft 23' in the following fashion. As indicated particularly in FIGS. 1 and 2, the lower ends of a pair of parallel spaced rods 32 are affixed by a cap screw retainer assembly 31 to the upwardly facing side of platen 15. Rods 32 project through the laterally spaced apertures 33 in platen 17. Each of the roller carriages 36 affixed to the upper end of a rod 32 is provided with an idler roller 42 that engages the outer periphery of a cam 34 I ample, a pair of fixed pins not shown which depend from top plate 21 and slidably engage the apertured opposed ends, not shown, of a carriage 36 in conventional fashion. Rollers 42 for a movable platen are maintained in positive rolling engagement with their associated cam on shaft 23' during the rotation thereof by a biasing mechanism continuously acting on movable platen 15 as will now be described. The biasing mechanism generally comprises a pair of spaced jack-like platen guide rods 44 and pneumatically actuated piston cylinder devices 46 connected thereto. Each device 46 is dependingly affixed to the underneath side of an apertured plate 51 provided in the base of the framework at opposite ends thereof. The rod end of the piston rod 47 subassembly of a given device 46 projects upwardly through an aperture in plate 51 as best shown in FIG. 1. Apertured bosses 48 are partly and dependingly inserted and locked within openings 49 on either side of top framework plate 21.
Apertured bosses 50 are affixed to the top of plate 51 mounted on the piston and cylinder device 46 at opposite ends of the press. Jack-like rods 44 are journably and slidably disposed within the opposed apertured bosses 48 and 50. Moreover, an intermediate portion of a given rod 44 is journably connected to fixed platen 14 as indicated at 50 in FIG. 1. The lower end of a rod 44 can be suitably connected to the piston rod subassembly 47 of a piston cylinder device 46 when the lower end of the rod 44 is inserted within a boss 50.
The ends of movable platen 15 are provided with downwardly depending and apertured support ears 52 and the apertured end of an ear 52 is aligned with platen aperture 53. The intermediate portion of the rod 44 fits within the aperture 53 and the apertured car 52 is appropriately keyed to rod 44 so that an upward urging of rod 44 will also urge platen 15 upward. A line 55 connected at one end to a piston cylinder device 46 and at the other end to a pressurized air source, not shown, operates to continuously supply air under pressure to the piston side of its associated device 46. If necessary, a control valve 57 and a check valve 59 can be located in line 55 in the manner shown in FIG. 1. When both lines 55 introduce air under pressure to their associated device 46 of a pair of devices, piston rod subassemblies 47 are biased upwardly together with rods 44 and platen 15. This upward biasing of platen 15 causes rollers 42 interconnected with platen 15 by way of rods 32, etc., to engage and remainengaged with cams 34 on drive shaft 23'.
In an advantageous embodiment of the invention fixed platen 14 can be provided with a plurality, for example, four suitably spaced apertures 62 disposed between opposite ends of framework 12, one for each punch and die assembly 19. A tool fitting 56 is fitted within each aperture. Each tool fitting 56 includes a workholder 58 provided with a central aperture 57 and an outer ring connected thereto. A given too] fitting 56 can be affixed to platen 14 in an appropriate manner. Each ring 60 and workholder 58 have matching shoulder elements 70 and 72 and the bottom ofa ring 60 is cut away to define an annular recess or receptacle 66 for receiving a coil spring 68. Upon attachment of a tool fitting 56 to platen l4, springs 68 bear against the top surface of platen 14 and act to urge the shoulder 72 of a ring 60 against the shoulder of a workholder 58. This in turn means that top surface 74 of ring 60 will be urged into coplanar alignment with the top surface 76 of the workholder insert 75.
In a further advantageous embodiment of the invention, the platen 15 is provided with a plurality of apertures, for example, the four apertures 77, each of which is aligned with an aperture 62 in platen 14. A workholder die element 78 of a punch and die assembly 19 is inserted in each aperture 77 in the manner shown in FIGS. 1-2.
A die element 78 generally comprises a generally cylindrically shaped female die insert 80 provided with a reduced neck portion 81 at one end and a flange 83 at the other end surrounded by a keeper ring 82. Die insert 80 has an enlarged aperture 85in its flanged end 80 and a smaller aperture 87 at its reduced end 81 thereof all as indicated in FIGS. 1, 34, and
68. A radial shoulder 89 interconnects apertures 87 and 85. Ring 82 and its associated die insert are provided with complementary shoulders 91 and 92 respectively, and a series of cap screw assemblies 95 are employed to secure keeper ring 82 and female die insert 80 to platen 15. Sheet stock S in FIG. 1 is incrementally fed along pass line L between fixed platen 14 and movable platen 15 at approximately 80 of an operative cycle as designated by point 99 in FIG. 8. During incremental feeding of stock S, it is supported by the top surfaces 74 and 76 of the various tool fittings 56. Upon rotation of shaft 23 from about [00 of an operative cycle of the apparatus 10, reference being made to FIG. 8, movable platen 15 is advanced towards fixed platen 14 until opposed tool elements 56 and 78 of a given punch and die assembly 19 clampingly engage a selected portion of the sheet stock S at approximately 180 of an operative cycle as generally indicated at point 101 in FIG. 8. As movable platen 15 continues to advance towards fixed platen 14, ring 82 of a die element 78 contacts the opposed ring 60 of an associated tool fitting 56 and causes a compression of the spring 68 whereby inner peripheral cutting edge 98 of ring insert 96 on ring 82 can cooperate with the outer peripheral edge 100 of upper end face insert 75 of die portion 58 which now becomes exposed to effect severance or blanking out of a workpiece or disc W from the sheet stock S during a given operative cycle of the apparatus at about point 101 in FIG. 8. The remainder of the severed sheet stock S is clampingly or otherwise disposed between opposed rings 60 and 82 of the given assembly until the stock is again incrementally advanced through the press for another operative cycle thereof as somewhat indicated in FIG. 1.
Since face 102 of the insert 104 for flange 83 of the female die 80 is offset inwardly of the surface 97 of ring 82 thereof, a pocket is provided for the severed blank W.. This allows the blank to be loosely yet firmly held, between opposed surfaces 76 and 102 of opposite die portions 58 and 80 of a given assembly 19 when platen 15 is fully advanced towards fixed platen 14 while the remainder of sheet stock S is clampingly held between the opposed die ring surfaces 74 and 97 of a given assembly as aforedescribed. The remainder of sheet stock S remains clampingly held between opposed ring surdicated particularly in FIG. 1, lower movable platen 16 is interconnected to drive shaft 23 as follows. Opposed ends of platen 16 are provided with depending and apertured ears 108. Ears 108 and adjacent parts of platen 16 are provided with common openings 110 for slidably receiving rods 44. Each ear 108 is equipped with a pin 112 for connecting the ear to a crank rod 114. Crank rod 114 is passed through the aligned apertures 115 and 116 in plate 21 and platen 14 respectively and the upper end of the crank 114 is connected to its respective cam 118 provided on shaft 23.
The topmost movable platen 17 is connected to shaft 23 by way of apertured ears 122 provided with a pin 125 to which the lower end of a crank rod is pivotally connected while the upper end of rod 126 is pivotally connected to the other periphery of a cam 128 located on shaft 23' intermediate cams 34 and 118 all as shown in FIG. 1. In operatively connecting rod 126 to a cam 128, it is to be understood that the rod is slidingly fitted within an aperture 129 in plate 21. A rod 44 also passes through the opening 124 in ear 122.
By reason of the apertured ears 110 and 122 of rams l6 and 17 being slidably connected to guide rods 44, these rams are maintained in proper alignment relative to fixed platen 14 despite the compound movement imparted to crank rods 114 and 126 upon rotation of shaft 23' with cams 118 and 128 thereon.
As a result of rods 44 acting to restrain the lateral movement of rod 114 and 126 during rotation of shaft 18, the lower ends of these rods are left free to pivot about the pins 112 and 125 on the ears 108 and 122 of platens 16 and 17. The aligned apertures 115 and 116 in plate 21 and platen14, of course, are of sufficient lateral extent to provide adequate clearance for rods 114 that move in these apertures upon compound movement of the rods 114 during rotation of shaft 23'. Similarly, an aperture 129 in plate 21 is of sufficient lateral extent to compensate for lateral movement of a rod 126 therein upon compound movement of the rod 126 during rotation of shaft 23. In view of selective and controlled advancement of platens 16 and 17 by their respective pairs of crank rods 114 and 126 during rotation of shaft 23', each severed blank W is loosely, yet firmly, held between the opposed tool fitting elements 56 and 78 of a given punch and die assembly 19 so that it can be drawn and reverse drawn into a container body C as will now be described.
Movable platen 16 is advantageously provided with a plurality of laterally spaced apertures, for example, four apertures 130, aligned with apertures 62 on platen 14. A hollow and stepped punch element 132 that forms a major part of the overall punch and die assembly 19 is fitted within aperture 130 of platen 16 so as to project upwardly therefrom in the manner shown in FIGS. 1-2 and 5-7.
Punch element 132 is comprised of an enlarged base portion 133 directly secured to platen 16 by cap screw and retainer subassembly 134. Punch element 132 includes an intermediate reduced portion 134 adapted to be concentrically and freely inserted in the aperture 62 of platen 14. The outer surface 135 of the upper or forward end 136 of element 132 has a diameter smaller than the outer surface of intermediate portion thereof so that it can fit within opening 57 of die ele ment 58 or the enlarged aperture 85 of the die member 80. Punch 132 when attached to platen 16 as aforedescribed projects above platen 16 such that the nose 137 on the forming end 136 will remain slightly spaced from annular shoulder 89 of die 80 upon the advancement of platen 16 towards fixed and movable platens 14 and as shown in FIGS. l-2 and 58 during operation of the press.
Movable platen 17 is provided with a plurality of apertures, for example, four apertures 140 all aligned with apertures 62 in fixed platen 14. A generally solid punch element 142 comprised of a base section 143 and a punch section 144 is affixed to and carried by platen 17. Base section 143 ofthe punch 142 is made up of a body portion 145 which carries an outer flange 146. The base section of a punch is provided with an axial bore 148 having an enlarged counterbore at the outer flanged end 146 thereof. The reduced end 149 of punch section 144 fits in the counterbored end of bore 148 all as indicated in FIG. 2 and cap screw assembly 150 is used to lock punch section 144 to base section 143. Cap screw assemblies 152 are used to directly secure outer flange 146 of the punch device 142 to platen 17 adjacent an aperture thereof whereby a punch 142 will be attached to platen 17.
The outer surface 153 of punch 144 has a diameter that is smaller than the diameter of the opening 85 of the die element 80 affixed to platen 15. Punch 144 has a length such that it will project below the bottom side of platen 15 when punch 144 is moved into the hollow interior of the larger punch element 132 during the reverse drawing part ofa press cycle.
After the movable platen 15 and a die element 78 thereof has commenced its advancement towards the top side of fixed platen 14 to effect severance of a workpiece disc from the sheet stock S during a press operating cycle, punch 132 of each punch and die assembly 19 is progressively advanced from its bottommost position at point D or 140 of an operative cycle of the apparatus in FIG. 8 until the forward or leading end of the punch initially engages the severed blank at point 155 or approximately 190 of the same operative cycle.
Continued advancement of platen 16 and the punch 132 of each assembly results in the punch advancing the blank W into the die aperture 85 of the die 80 and causing it to assume a shallow cup-shaped configuration along the lines of that shown in FIG. 6. The depth of die aperture 85 can be greater than the depth of the sidewall of the drawn workpiece W and the advancing punch 13 will normally effect this full first drawing of the workpiece at approximately 250 of an opera tive cycle as indicated at 156 in FIG. 8. Such full drawing of a workpiece W by an advancing punch 132 at approximately 250 of an operative cycle is required so that the blank W will be properly ready for reverse drawing by punch 144 which begins to move downwardly from its topmost position A at approximately l of an operative cycle into final engagement with the bottom of the partly drawn. workpiece W when the opposed strokes of both advancing punches 144 and 132 of the given assembly initially overlap at the aforementioned or common point 156 at approximately 250 of an operative cycle. During continued advancement of the punches 144 and 132 in overlapped relation from their mergence at point 156 in this operative cycle, the initially drawn workpiece W becomes partly reversely drawn into a container C about the forming end of punch 144 before punch 132 reaches its topmost position at point E in approximately 320 of an operative cycle of the apparatus as indicated in FIGS. l-2 and 7 8.
At the same time, punches 132 and 144 overlap such as at point 156 on the graph of FIG. 8, a die element 78 affixed to movable platen 15 is also advanced from its bottommost position indicated at the aforementioned point on the graph of FIG. 8 to its topmost position indicated at 158 on the graph at a rate substantially consistent with the rate of advancement of movable punch 132 from an intermediate position adjacent to point 156 on the graph to its topmost position at point B thereby preventing injury to an initially drawn workpiece W during the reverse drawing thereof as shown in FIGS. 1-2 and 68.
In another advantageous embodiment of the invention, the forward end 137 of punch 132 of a given punch and die assembly 19 is provided with an improved container stripper element in the form of an inwardly directed radial flange 154 having an inner radial shoulder 159. Shoulder 159 engages the open end of the container C disposed about the forming end of punch 144 and effectively strips the container W from punch 144 as punch 144 backs away from punch 132.
With further reference to FIG. 8, after redrawing of the initially drawn workpiece W into the container C, maximum overlap of punches 132 and 144 of a given assembly 19 occur between successive points E and B on the graph. This maximum overlap of punches 132 and 144 assures that the open edge of container C disposed about punch 144 will be p0sitioned within the hollow interior of punch 132 and below shoulder 159 thereof.
After punch 132 passes its topmost position E on the graph andjust prior to punch 144, bottoming at point B thereon, the open end edge of container C is drawn into engagement with shoulder 159 of punch 132 as indicated at 160 or at approximately 355 ina full cycle press operation. This engagement results in the container being fully stripped from about punch 144 at approximately 55 of the immediately subsequent press cycle of operation or at the point 161 of the graph in FIG. 8 as punches 132 and 144 progressively disengage from each other. In order to prevent the creation of a vacuum between container C and punch 144 during stripping of the container from about the punch, punch 144 and base section 143 thereof are provided with a conventional vent opening 162. As a stripped container C freely drops or falls away from punch 1441 under the influence of gravity within the channel formed by the interior of punch 132 towards the open bottom at the lower end of the interior thereof whereby the formed container is ejected from the apparatus and the fully ejected containers C can eventually drop into a collection receptacle or conveyor, not shown.
After container C is stripped from a punch 144 at point 161 on the graph or at about 55 of the press operative cycle, punch 132 and punch 144 remain fully separated after point 163 thereon or at about 70 thereof until the leading end of punch 132 engages the next workpiece to be formed in a container C during the next operative cycle of the apparatus. It is also observed at this time that a feeder device (not shown) intermittently advances another section of sheet stock S at about 80 or point 99 of an operative cycle into the press between platens 14 and 15 while removing the blanked-out or used section of the stock S.
The uniquely combined punch drawing die and stripper element 132 simplifies the stripping operation and makes the press less susceptible to jamming even when operating at greater than 140 strokes per minute.
The control system for detecting a malformed container C will now be described.
This control system as indicated particularly in FIGS. 1 and 3 includes a three-phase motor M having input leads 161. These leads 161 are connected to an input source usually A.C. not shown. A suitable on-ofi switching circuit, not shown, is appropriately connected to these leads 161 for selectively energizing motor M during operation of apparatus 10. Upon energization of motor M it will cause rotation of shaft 23' via belt 25, etc., unless clutch 24 is disengaged by reason of the control system detecting a malformed container C during a press operative cycle as will be described below.
Each of the punches 144 is advantageously provided with a plurality of interconnected passageways 166 for continuously discharging air in different directions and against preselected areas on the inside wall of a container C in order to detect whether the container has been fully formed, i.e., as a fully formed wall along the entire periphery of the container at a pre-chosen P, toward the end of the operating cycle. Three of these passageways are disposed in the same general plane transversely of the longitudinal punch 144 and rearwardly of the front edge of the punch 144 by the preselected distance U. The distance U is somewhat less than the minimum tolerance depth'V of a sidewall portion of the properly formed container C. Thus, the minimum tolerance depth extends between the opened end edge of the container and the bottom end thereof as shown in FIG. 4.
A fourth passageway 166 in punch 144 communicates with the other passageways while being disposed longitudinally of punch 144. The aforesaid network of passageways intersect at point 167 and is supplied with air by way of passageway 170 connected to air conduit 174 which in turn is connected to a main air manifold 172. Manifold 172 supplies a continuous flow of air at a selected pressure and flow rate from a source not shown to each conduit 170 of a given punch during continuous operation of the apparatus. If desired, a valve 173 can be connected to conduit 172 for precisely regulating the pressure and volume of air. Additionally, a filter 175 can be connected to conduit 172 in order to assure that clean air is supplied to each one of the four interconnected passageways 166 of any given punch, thereby preventing inadvertent blockage of any one of the four passageways of the punch during operation of the apparatus. A fluidic amplifier 180 is connected to its respective punch 144 by a conduit 178 connected across the amplifier and the associated conduit 174. Each one of the four amplifiers 180 is connected across pneumatically triggered or operated electric device 176 by its respective conduit 179.
Although air is continuously discharged from the aforesaid passage in a punch 144 at a selected volume rate and pressure during operation of control system 11, the control system does not function to sense the presence of malformed and properly formed containers C until a pre-chosen point P, in an operative cycle of the apparatus is reached.
Thus, for example, the container C should not be sensed by the control system until about 335 of the operative cycle at which the strokes of punches 144 and 132 of a given assembly 19 are at a maximum overlap position prior to stripping of the container from about the forming end of the associated punch. Accordingly, pre-chosen point P, is preferably selected at about' 335 of an operative cycle as indicated in FIG. 8. Moreover, when a punch 144 is at 335 of an operative cycle, the punch is still advancing in the same direction as during previous reverse drawing of a drawn workpiece W into a container C, thereby assuring that the container formed about its associated punch 144 is in substantially full engagement therewith during operation of the apparatus. Such full engagement of the container about its associated punch at point P, of an operative cycle guarantees proper sensing by the control system.
Thus, as indicated in the graph of FIG. 8, at point P, of an operative cycle, if the container is properly formed about its respective punch 144, the discharge ends of the four interconnected passageways 166 of the punch will be substantially blocked-off or covered by their associated inside surface portions of the formed container, as shown in FIG. 4. This blockage of all four passageways of a punch 144 by the container disposed thereabout causes generation of a reaction or static back pressure pulse in each of the four passageways of a punch 144. The reaction pressure pulses of the four passageways of a punch are cumulatively transmitted through lines 174 and 178 to their operatively associated amplifier 180. An amplifier is preferably preset to be triggered when the reaction pressure pulse in its associated lines 174 and 178 is indicative of blockage of all four passageways of a given punch 144. When the amplifier is triggered upon receiving the cumulative pulse or signal from its operatively associated punch it acts to transmit an amplified pneumatic pulse through its associated conduit 179 to the master control device 176.
Thus, when a container C disposed about its punch 144 at point P, is malformed because of a fractured bottom which might be due to an unknown metallurgical defect in the workpiece W severed from sheet stock S during operation of the apparatus, the discharge end of the longitudinal passageway of the punch about which the malformed container is disposed is not sufficiently blocked at point P, of an operative cycle of the apparatus. This insufficient blockage of longitudinal passageway 166 of punch 144 at point P, of an operative cycle of the apparatus causes a reduced or no-back-pressure signal in longitudinal passageway 166 of the punch. This results in transmission of a reduced cumulative signal from punch 144 through conduit 174 to its associated amplifier 180. The amplifier is so constructed and arranged that when it receives a reduced cumulative back pressure signal from its respective punch, it is not triggered for transmitting an output amplified signal through its respective conduit 179 to sensor device 176.
A suitable type amplifier is model No. SOA-OlO of the Norgren Inc, of Denver, Colorado. Accordingly, if any one of the four amplifiers receives a reduced signal from its associated punch at point P,, the four amplifiers are not simultaneously triggered for transmitting their amplified signals through four conduits 179. Device 176 is so constructed as to be triggered only if simultaneously receiving the aforesaid four amplified signals. A suitable type sensor device is one sold by the Wintress, Inc. of New York, N.Y., under Model No. FI16-OXXX.
Thus four amplifiers 180 in effect act as interlocks for effectively preventing triggering of device 176 unless four containers C are properly formed about their respective punches 144 at point P, of an operative cycle of the apparatus during operation thereof.
It is observed that the flow of air discharged from the four interconnected passageways of a punch 144 is at a selected rate and pressure that will not generate a force in excess of the frictional force of engagement of the formed container about the punch during operation of the apparatus. Consequently, the container is positively retained about its punch so as not to adversely affect the overall sensitivity of the control system in accordance with the teachings of the instant invention.
In order for device 176 to be electrically energized at the same time it is pneumatically triggered by the combined pulses from four amplifiers 180 at pre-chosen point P, during an operative cycle of the apparatus 10 as aforedescn'bed, the device 176 is also series connected by branch conduit 181 across input leads 159-160. A cam 186 is rotatably connected to common shaft 23' and includes a single raised lobe 187, as indicated in FIGS. 1 and 3. A branch conduit is connected to electromagnetic sensor 188 across input leads 159-160 in order to effect energization of the sensor for generating an electromagnetic field F, as indicated in FIGS. 1 and 3. Sensor 188 is affixed to framework 12 in conventional fashion so as to be disposed in spaced and operative relation to cam 186 during rotation of shaft 23'.
In affixing cam 186 to shaft 23, its cam lobe 187 is positioned relative to shaft 18 such that it passes sensor 188 at prechosen point P, of an operative cycle of the apparatus during operation thereof. As the cam lobe passes through the magnetic field F, of the sensor when apparatus 10 is at pre-chosen point P, of an operative cycle thereof, it induces a greater counterreactance in the sensor. This greater counterreactance induced in the sensor causes transmission of an output signal from sensor 188. This output signal transmitted from sensor 188 through leads 192 to solenoid 194 causes energization solenoid 194. Such energization of solenoid 194 advances normally open solenoid contact 194-1 into contact across solenoid contact bridging terminals 196 of lead 181, thereby energizing solenoid device 176 if it has been substantially simultaneously triggered by the combined pneumatic pulses transmitted from four amplifiers 180 at pre-chosen point P, of an operative cycle of the apparatus, as aforedescribed.
Energization of solenoid 176 causes normally open solenoid contacts 176-1 to be advanced into bridging contact across bridging terminals 200 of branch lead 215. Solenoid 210 is connected to branch lead 214 and branch leads 214-215 are series connected across input leads 159-160 in order to provide an alternate or secondary energizing circuit across solenoid 210. On the other hand, branch lead 216 is connected to branch lead 215 whereby branch conduits 214 and 216 are connected across input leads 159-160 for forming a primary energizing circuit across solenoid 210. Thus, prior to energization of device 176 for forming an alternate circuit by leads 214-215 across solenoid 210, solenoid 210 is normally energized by the circuit formed by conduits 216 and 214. Solenoid 210, upon energization by either circuit of leads 214-215 or 214 and 216, functions to energize a standard solenoid valve (not shown) in device 24. Such energization of the solenoid valve admits air under pressure from conduit 217 for maintaining the clutch (not shown) in device 24 in coupling engagement with shaft 23'. In the event solenoid device 176 is not energized at pre-chosen point P, of an operative cycle of the apparatus as aforedescribed, solenoid 210 will be deenergized when both circuits of leads 214-215 and 214 and 216 are open at predetermined point P of an operative cycle of the apparatus.
A second cam 218, having a single raised lobe 220, is advantageously rotatably connected to shift 23' for efiecting stoppage of apparatus 10 at a predetermined point P during an operative cycle of the apparatus. With reference to FIG. 8, the most advantageous point for stopping the apparatus 10 during an operative cycle thereof if a container is malformed as detected by the control system at pro-chosen point P,, is when punches 132 and 144 of movable platens 16 and 17 are respectively spaced below and above opposite sides of the top surface of fixed platen l4. Punches 132 and 144 of a given assembly are respectively spaced below and above opposite sides of fixed platen 14 when apparatus 10 is at approximately I l of an operative cycle. Accordingly, predetermined point P is advantageously located at about 1 of an operative cycle, as indicated in FIG. 8. When apparatus is stopped at predetermined point P upon detection of a malformed container C by the control system, the operator has immediate access into the interior of the press for servicing purposes. Even though a malformed container C has been stripped from its associated punch at 55 of an operative cycle as indicated in FIG. 8, it is to be understood that an appropriate visual indication device (not shown) can be interconnected between each one of the four amplifiers 180 and device 176. It is to be understood, of course, that such a visual indication device is only operably responsive when its operatively associated amplifier 180 is not triggered at pre-chosen point P,
during an operative cycle of the apparatus. Thus, upon stoppage of the press at predetermined point P one or more visual indication devices when energized upon nontriggering of their associated amplifiers will enable the operator to immediately determine which one or more of the four assemblies 19 is responsible for producing malformed containers during the interrupted operative cycle: of the apparatus.
An electromagnetic sensor 222 is series connected across input leads 159-160 by way of branch conduit 223. Energization of sensor 222 by conduit 223 causes the same sensor to generate an electromagnetic field F Cam 218 is disposed in operative relation to sensor 222 such that lobe 220 is arranged to pass through field F of sensor 222 when the apparatus is at predetermined point P of a given operative cycle thereof. When cam lobe 220 passes through field F it causes inducement of a greater counterreactance in sensor 222. Thus, sensor, as the result of the inducement of the greater counterreactance, transmits a signal to solenoid 224 through conduits 226 interconnecting solenoid 224 and sensor 222. The solenoid, upon receiving the signal, is energized thereby opening normally closed solenoid contacts 224-1 which normally bridge across spaced terminal contacts 228 of branch conduit 216. When normally closed bridging contacts 228 are opened, solenoid 210 is electrically disconnected from input leads [59-160 through the primary energizing circuit formed by conduits 214 and 216. At the same time, if normally opened bridging contacts 200 have remained open as the result of a malformed container being detected by the control system at pre-chosen point P,, solenoid 210 is also electrically disconnected from input leads 159-160 through the alternate circuit of conductors 215 and 214. Consequently, solenoid 210 is deenergized and the solenoid contact (not shown) of solenoid 210 thereof is advanced to a position for deenergizing the solenoid operated valve (not shown) of device 24. The deenergized valve (not shown) of device 24 then closes off conduit 217 whereby the clutch (not shown) of device 24 is disengaged while the brake (not shown) thereof is simultaneously engaged, thereby stopping the apparatus at' predetermined point P of an operative cycle for servicing thereof. Such stoppage by the control system of the instant invention advantageously prevents excessive injury to the improved apparatus that would otherwise occur.
On the other hand, if solenoid 176 is energized by the control system 11 at pre-chosen point P,, the apparatus will continue operation for the next operative cycle, etc., until an improperly formed container is detected by the control system. It is to be understood that solenoid 176 includes appropriate time-delay circuitry (not shown) for maintaining solenoid 176 energized between points P, and P in FIG. 8. Thus, solenoid 176, when electrically energized, connects the alternate circuit ofconduits 215-214 across input leads 159-160, thereby maintaining energization of solenoid 210 even though the primary circuit of conduits 214 and 216 across input leads 159-160 are momentarily interrupted as the result of conduit 216 being disconnected upon energization of solenoid 224 by cam 220 at predetermined point P of an operative cycle of the apparatus. Accordingly, if apparatus 10 is not stopped at predetermined point P, by the control system, the apparatus automatically operates for the successive operative cycle, etc.
Although not shown in FIG. 3, appropriate switches can be connected to branch conduits and 223 for selectively energizing and/or deenergizing sensors 188 and 222 such as when apparatus 10 is being operatively cycled without the feeding of a length of sheet stock 5 therethrough.
By virtue of improved apparatus 10 of the instant invention and the unique control system therefor, the apparatus is capable of producing containers at a rate greater than 140 containers per minute. Although apparatus 10 has been disclosed as operating in a vertical upstanding position, it is to be understood it could be operated in other positions, such as horizontal as at an angle to a horizontal plane wherein appropriate means can be provided for effecting ejection of the container after stripping thereof by punch 132. Depending upon the production requirements for apparatus 10, one or more assemblies 19 can be used. Moreover, even though an operative cycle of apparatus in FIG. 8 is shown as being programmed for stripping a container C at 55 thereof, the operative cycle can be programmed in any desired fashion such as, e.g., punch 132 being at the bottom of its stroke (point D in FIG. 8) at 0 of an operative cycle.
Advantageous embodiments of the instant invention have been disclosed and described. It is obvious that various changes and modifications may be made therein without de parting from the appended claims, wherein:
What is claimed is:
1. A press of the type described comprising a selectively movable hollow punch means and a selectively movable solid punch means receivable within the hollowed-out portion of the first punch means, a cup-shaping die means interposed between said hollow and solid punch means and provided with a pocket for selectively receiving said hollow punch means as well as as a workpiece, means for moving said hollow punch means into engagement with the workpiece held in the pocket of said cup-shaping die means in order to initially draw the workpiece into a cup, means including the solid punch means for progressively displacing the cup-shaped workpiece from the pocket of said die means while at the same time reversely redrawing and reshaping the cup-shaped workpiece into a container about the forming end of said solid punch means upon insertion of said solid punch means into the interior of said hollow punch means, and shoulder-like means provided at the forwardend and within the interior of said hollow punch means for engaging and stripping the formed container from said solid punch means during extraction of said solid punch means from the interior of said hollow punch means.
2. A press as set forth in claim 1 in which said cup-shaping die means is comprised of a fixed portion and a movable portion operatively associated therewith with said movable portion having said pocket.
3. A press as set forth in claim 1 in which said cup-shaping die means includes means for serving a disc-shaped workpiece from a length of sheet stock intermittently fed to said press.
4. A press as set forth in claim 1 in which said solid punch means includes atmospheric venting means in order to prevent the creation of a vacuum between said solid punch means and a formed container upon stripping of the container from said solid punch means.
5. A press as set forth in claim 1 in which said cup-shaping die means is provided with workholder means.
6. A press of the type described comprising a selectively movable hollow punch means and a selectively movable solid punch means receivable within the hollowed-out portion of the first punch means, a cup-shaping die means interposed between said hollow and solid punch means and provided with a pocket for selectively receiving said hollow punch means as well as a workpiece, means for moving said hollow punch means into engagement with the workpiece held in the pocket of said cup-shaping die means in order to initially draw the workpiece into a cup, means including said solid punch means for progressively displacing the cup-shaped workpiece from the pocket of said cup-shaping die means while at the same time reversely redrawing and reshaping the cup-shaped workpiece into a container about the forming end of said solid punch means upon insertion of said solid punch means into the interior of said hollow punch means, means carried by said solid punch means for directing a gaseous medium against selected portions of the workpiece for detecting a malformed container and for operating a control mechanism that stops the press upon such detection, and shoulder-like means provided at the forward end and within the interior of said hollow punch means for engaging and stripping a container from said solid punch means during operation of said press.
7. A press as set forth in claim 6 in which said solid punch means also includes an atmospheric venting means in order to prevent the creation of a vacuum between said solid punch means and a formed container during stripping of the container from said solid punch means.
8. A press set forth in claim 6 in which the cup-shaping die means is comprised of fixed and movable portions.
9. A press of the type described comprising a movable hollow punch means and a movable solid punch means receivable within the hollowed-out portion of said first punch means, a cup-shaping die means interposed between said hollow and solid punch means and comprised of a fixed portion and a movable portion, said movable portion having a pocket for selectively receiving said hollow punch means and workpiece, means for moving said hollow punch means into engagement with the workpiece held in said pocket in order to effect drawing of the workpiece between said hollow punch means and the movable portion of said cup-shaping die means so as to effect formation of the workpiece into a cup, means including the solid punch means for progressively displacing the workpiece from the said pocket while at the same time reversely redrawing and reshaping the cup-shaped workpiece into a container about the fonning end of said solid punch means upon advancement of said solid punch means into the interior of said hollow punch means, means carried by said solid punch means for directing a gaseous medium against selected portions of the workpiece for detecting a malformed container container and for operating a control mechanism that stops the press upon such detection, and said hollow punch means including a shoulder-like means disposed in the interior of said hollow punch means for engaging and stripping a container from said solid punch means during operation of the press.
10. A press as set forth in claim 9 including guides means for maintaining said hollow and solid punch means and the movable portion of said cup-shaping die means in alignment relative to the fixed portion of said cup-shaping die means during relative movements of the said punch means and the movable portion of said cup-shaping die means.
1 l. A press as set forth in claim 9 including crank rod means connected to said hollow and solid punch means and to the movable portion of said die means for effecting relative movements of said hollow and solid punch means and said movable portion.
12. A press as set forth in claim 9 in which said gaseous medium detecting means comprises an air jet means.
13. A press as set forth in claim 12 in which said control mechanism comprises a fiuidically-actuated electromechanical device.