Abstract:
Transfer apparatus and method are provided from first ( 15 A,  16 A) to second ( 15 B,  16 B) stations of tooling in a cap ( 11 ) making press. This cap is biased against the first upper tools by a first airstream ( 50 ) introduced under the cap and moves upward with the first station punch ( 45 ). As the punch approaches its top location, a transfer airstream ( 52 ) begins while the first airstream is still on, and moves the cap out through a transfer chute ( 18 ) to the second station. The cap departs the chute and passes detents ( 67 ) on a pair of closed retention fingers ( 60 ) which define an extension of the transfer path from the chute into the open second station tools. A vacuum ( 85 ) applied to a port in the second station punch then holds the cup against the rising upper tools. When the punch clears the closing fingers and approaches its top location, an ejection airstream ( 87 ) commences to propel the finished cup via a discharge chute ( 19 ).

Description:
This application is a 371 filing of PCT/US2001/49392, filed Dec. 19, 2001, which claims priority from U.S. provisional application Ser. No. 60/257,336, filed Dec. 20, 2000. 
    
    
     BACKGROUND OF THE INVENTION 
     U.S. Pat. Nos. 6,082,944 and 6,015,062, assigned to the assignee of this application, disclose closure constructions for reclosable containers (e.g a can body) wherein a domed container end with a neck portion having a pour opening is provided with a reclosable lugged type of cap. That invention provides a unique and versatile container for fluids, particularly for beverages, wherein various standard can bodies are provided with a two part end including a neck with a pour opening, a lug formation on the neck below the pour opening, a reclosable cap having a lug formation which can interlock with the lug formation on the neck and including a seal surrounding the pour opening, and thus capable of maintaining product under pressure. The two part end is affixed to a can body by conventional double rolled seam attachment between the bottom of the neck and the rim of the can body. However, it is possible to affix the domed end to a can body without a cap, fill the can though the pour opening, and then apply the cap. 
     With the possibility of expanded markets for these lugged caps, which are also useful on various jars and bottles, there is a need for a system (method and tooling) for producing lugged cap members in a single machine, e.g. a reciprocating press fitted with appropriate tooling, which is capable of precise high speed (e.g. in the range of 135 to 150 strokes/minute) to achieve acceptable commercial production of the cap. 
     To develop such production speeds it is desirable to divide the progressive tooling operations into more than one step, and this in turn requires a rapid and precise transfer system to move the partially completed caps from a first station to a second station, and precisely register the caps in the second station. Prior art transfer systems are known for moving and registering can end shells, such as in U.S. Pat. Nos. 4,770,022 and 4,895,012, however, the end shells are relatively flat disc-like objects with a quite small height to diameter ratio, whereas the caps made by the present invention have a substantially greater height with respect to their diameter. 
     Thus, the physical dimensions of the caps involved in this invention are quite different from can shells or easy self-opening can ends. This in turn introduces needs not required or anticipated in shell transfer systems, for example with regard to tipping of the caps during high speed transfer operations. Also, because of the relatively high press cycling, and need for precision in cap positioning and deceleration immediately after each transfer to another press station, there is a requirement for precise transfer of each cap from a first press station through high acceleration, very rapid transfer to the next press station, and high deceleration to a precisely defined stationary location at that next station. 
     SUMMARY OF THE INVENTION 
     The present invention provides a transfer apparatus and method for a first to a second station of progressive tooling in a cap making press. The caps are of a type having substantial height with respect to their diameter. Thus a first station punch and die form a cap of generally inverted cup shape, with an outward curled rim, and a second station punch and die form lugs into that rim, requiring just two strokes of the press to sever a disc from a supply sheet, form it, and discharge a completed cap. 
     Thus, in the first station, a cap is formed except for lugs which are added to the cap in the second station. The formed cap in the first station, which is in the nature of an inverted cup, has an outward curl formed on its lower edge during the initial up stoke of the press. This cup is then biased against the upper forming punch, by a first airstream introduced into the cavity within the underside of the cap, and moves upward in contact with the first station punch. As the punch approaches its top dead center location (tooling fully open), a second airstream begins, before the first station punch is fully raised and while the first airstream is still on. This second airstream moves the cap off the raised first station punch, and into and through a transfer chute directed toward the second station. 
     At the second station, the cap departs the chute and passes detents on a pair of closed retention fingers which, with the tooling open, define an extension of the transfer path from the chute into the open second station tools. As the second station tools begin to close and the partially finished cap is located, the fingers are opened and the tooling operates to form lugs into the cap rim. 
     As the second station tooling opens, a vacuum applied to a port in the second station punch begins to hold the finished cup against that punch tool, and when that punch clears the closing fingers and approaches its top dead center location, an ejection airstream commences to propel the finished cup from the tooling via a discharge chute. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a bottom view of a container cap as provided by the invention. 
         FIG. 2  is a transverse cross-sectional view of a typical completed cap, as shown in  FIG. 1 . 
         FIG. 3  is an over all perspective view of the tooling for a four-out cap making system. 
         FIG. 4  is an enlarged perspective view, with the die shoe removed, showing details of the tooling, including four first station tools in the center and four related second station tools outwardly in opposite directions of the first stations. 
         FIG. 5  is a further enlarged perspective view showing details of one pair of first and second stations of the tooling. 
         FIG. 6  is a cross-section view of a first station punch or upper tool. 
         FIG. 7  is a cross-section view of a first station die or lower tool. 
         FIG. 8  is a cross-section view illustrating the first station punch and die in closed position, and showing a cap formed except for an outward curl at the lower rim of the cap. 
         FIG. 9  is a cross-section view showing first station and corresponding second station tools, a transfer chute between them, the fingers which provide an extension of the chute into the second stage tool, and cams which control movement of the fingers. 
         FIGS. 10 and 11  are detail views of the top of the second station die, showing the open and closed positions of the fingers. 
         FIG. 12  is an enlarged cross-section view of the second station tools, and  FIG. 12A  is a further enlargement of the circled area in the center of  FIG. 12 . 
       FIGS.  13 A and  13 B 1  &amp;  13 B 2  (three sheets) together are a schematic diagram of the pneumatic supply &amp; control system of the press and tooling. 
         FIG. 14  is a flow diagram of the electronic control system for the tooling package. 
     
    
    
     DESCRIPTION OF PREFERRED EMBODIMENT 
     The present invention provides a transfer apparatus and method for two station progressive tooling in a cap making press and system. The caps are of a type having substantial height with respect to their diameter. A typical such cap is shown in  FIGS. 1 and 2 , which is also shown in FIGS. 2, 4A and 4B of U.S. Pat. No. 6,015,062. The preferably integral cap  11 , in the general form of an inverted cup, includes a top panel  12 , a peripheral sidewall  13 , and a curled rim  14 . 
     In the present drawings,  FIGS. 3-12A  depict multi-lane progressive tooling comprising four lanes for simultaneously forming four caps  11 , each lane comprising pairs of first and second tooling stations  15 A,  15 B,  16 A,  16 B,  17 A, 17 B, and  18 A,  18 B, with the first stations  15 A- 18 A arranged centrally of the tooling ( FIGS. 3 ,  4  &amp;  5 ) and corresponding second stations  16 A- 16 B arranged outward of the first stations toward opposite sides of the upper and lower die plates  20 A,  20 B which support the upper (punch) and lower (die) tooling, and mount between the bed and slide of a reciprocating press (not shown). 
     Except for their orientation in the overall tooling package, the respective first station and second station tools are alike, and the following detailed description applies to all. Taking stations  15 A and  15 B as examples, each pair of corresponding first and second stations has an associated transfer chute  19  ( FIGS. 4 ,  5  &amp;  9 ) between them, and each second station has a discharge chute  19 A, the four of which are directed out opposite sides of the tooling ( FIGS. 3 &amp; 4 ). 
     Sheets of metal, with an appropriate pattern of lithographed materials for each cap, are fed centrally into the first stations by sheet feeding mechanism of known construction (not shown) which moves the sheets one at a time in step wise fashion, synchronized to the press strokes, along the feed path indicated by arrow IN in  FIGS. 3 &amp; 4 . 
     First Station 
     The first station tools comprise an upper or blank punch tool  45  and a compound lower die. During the initial operation of the first station tools, with the lithographed patterns aligned with respect to the first station tools, a blank is cut from the material (typically aluminum or thin cold rolled steel) on the down stroke of the press by blank punch  45 . On the continuation of the down stroke, the blank punch and lower die tool cooperate such that the blank is drawn into a cup shaped cap part  11 P ( FIG. 8 ). At the bottom of the stroke the panel shape  12  is formed into the top of cap part lip by the punch  45  and cooperating die  46  ( FIGS. 6 ,  7  &amp;  8 ). 
     On the up stroke, the lower curl ring  48 , which is under spring pressure, raises with the blank punch. The bottom edge of the cap part  11 P is curled outward into the cavity  49  formed by curl ring  48  and blank punch  45 , completing a formed cap  11  with an outward curled rim  15 . 
     The formed cap in the first station, which is in the nature of an inverted cup, is biased against the upper forming die by a first airstream introduced through passage  50  (see  FIGS. 8 &amp; 9 ) into the cap as the first station tooling opens, and causes the cap to follow upward against the bottom of the punch  45 . During the upward travel of the cap, a second airstream is initiated through a nozzle  52  directed across the upper first station tooling toward chute  19 , and is at its full power when punch  45  (with a cap  11  held thereto by the upward directed first airstream) traverses the space between nozzle  52  and the entry to chute  19  (see  FIG. 9 ). By the time the first station tooling reaches full open at the top-dead-center of a press stroke, the cap has actually been transferred into the second station  15 B; see Press Rotation timing chart below (page 8). 
     Thus, the first and second airstreams, appropriately switched on and off, together with the associated chute, constitute a first part of an essentially passive press transfer system. 
     Second Station 
     At the second station, a separated pair of fingers  60  reach around the sides of the second station tooling ( FIGS. 9 ,  10  &amp;  11 ), defining partial sides of a receiving space  62  when the second station tooling is open, and an extension of the transfer chute when closed. The fingers are supported by pivots  63  inward of their rear ends  61 , and are biased into their closed position ( FIG. 10 , forward ends parallel) by spring mechanism  64 . Each finger has a narrow ledge-like track  65  extending part way along its forward upper edge ( FIGS. 10-12 ), facing each other and ending in a curved section  66 . Extending horizontally inward over tracks  65  are spring-loaded ball detents  67  which, together with the curved track sections  66 , define the termination of the transfer path for the incoming caps. 
     A cap propelled from the first station traverses the adjacent transfer chute  19  and enters receiving space  62 , passing across ball detents  67  and resting against the curved track sections  66  (see  FIG. 11 ). The fingers and their operating mechanism form the remainder of the unique transfer system. 
     As the tooling proceeds to close during the beginning of a next stroke, fingers  60  are swung outward by descending cams  48  pressing against followers  49  on the rear ends  61  of the fingers to move the followers  49  inward and the forward section of the fingers outward ( FIGS. 10 &amp; 12 ) before the second station tools close. The elongated cams  48  are mounted on the upper (die) tooling base ( FIG. 12 ), and this action centers a cap ( FIG. 11 ) and then opens the fingers associated with the second station tooling, before that tooling closes to form lugs on rim  15  of a cap  11 . This closing action of fingers  60  is momentary, and they are then opened substantially before the second station tooling closes; see Press Rotation timing chart below. 
     In the second station  15 B in the press, the tooling includes an upper punch  70  and a lower die  72 . The punch tool  70  includes an annular knock out ring  71  with an inner shape conforming to a cap exterior, and a headed knock out pin  73  which is spring loaded toward a position flush with the lower edge of ring  71  ( FIGS. 12 &amp; 12A ) when the tooling is opened. In the lower die  72  there is a vertically extending tapered cam  74  mounted onto a base plate  75  and surrounded by a plurality of die pins  76  also mounted onto plate  75 . The cam  74  and pins  76  project through a vertically movable, upwardly biased ring  78  which contains a plurality of lug forming dies  80 , equal in number to pins  76  and movable laterally outward through forces from cam  74  as it is made to enter ring  78 . The top of ring  78  has an upper surface  82  contoured to fit within a cap  11 . 
     Thus, when the second station tooling closes a cap is positioned with the curled rim  15  between the upper ends of pins  76  and the radially outward moving forming dies  80 , to for the predetermined number of lugs in the rim ( FIG. 1 ). Then, the completed cap is held to the knockout pin by means of a vacuum created in passage  85  though the head of that pin  73 , such that the cap is carried upward past an air nozzle  87  directed across the path of the rising upper tool toward an associated discharge chute  19 A. The vacuum is created by air flow through a small venturi (not shown) so the vacuum is relieved immediately upon cessation of air flow through that venturi. A discharge air stream is started from nozzle  87  and moves the cap from the upper knock out ring and pin, into and through the associated discharge chute  19 . 
     Press Rotation Relation to Tooling Function 
     1st Station
         0° Top of the Stroke; Top Dead Center   140° Material is Blanked   180° Form &amp; draw complete; Bottom Dead Center; Cap Overall Height ˜0.810 inch   190° Cap Curl complete; Overall Height is ˜0.625 inch   190° 1st Air turned on; Blows cap against punch tool   220° Blank punch exits Die tool, cap against its face   230° 2nd Transfer Air on; Blows cap into transfer chute   330° 1st Cap arrives into catch fingers at 2nd Station.       

     2nd Station
         0° Top of a stroke; Top Dead Center   60° Upper vacuum is turned on   136° Catch fingers start open, upper vacuum holds 1st cap against upper knockout and tools close   180° Lugs formed in 1st cap; Bottom Dead Center   181° 1st cap (completed) and tools move up together   224° Catch fingers close completely after tooling passes   270° Upper vacuum to knockout turned off   280° Discharge air valve to nozzle is turned on   290° Knock out air to nozzle  87  is turned on   330° 2nd Cap arrives into catch fingers   336° 1st Cap actually moves to discharge position   335° Vacuum actually turns off on Cap #1   350° 1st Cap actually leaves press via chute  19         

       FIGS. 13A and 13B  comprise a pneumatic diagram for the pneumatic portion of the press control. A “shop air” source of compressed air is supplied to the various electrically controlled valves (which are all labeled) to direct air under pressure to the above mentioned parts of the tooling, under management control of the electronics control ( FIG. 14 ) of the system. The details of such controls are apparent to persons skilled in this art from these diagrams 
       FIG. 14  is a block diagram of electrical/electronics controls for the system, which selectively turn on and off the compressed air to the nozzles providing lift or “blow up” air to hold the cap part against the rising upper tools in the first station, and providing a transfer air stream to quickly move a cap part into a transfer chute  19 . The third (upper) control provides timed discharge airstreams through nozzles  87  to move the finished caps into the discharge chutes  19 A. A pulse generator PG is driven by the press crankshaft (not shown) in typical fashion to generate a train of pulses related to the angular position of the crankshaft as it rotates, and these pulses are directed to the system PLC (Programmable Logic Controller). Since the diagram is divided into three functions which occur during a press cycle, the controller PLC is shown in each of the three diagram parts, but in fact one PLC is employed in the control system. 
     While the method herein described, and the form of apparatus for carrying this method into effect, constitute preferred embodiments of this invention, it is to be understood that the invention is not limited to this precise method and form of apparatus, and that changes may be made in either without departing from the scope of the invention, which is defined in the appended claims.