Abstract:
An improved cap, and apparatus and a method for making such cap, including tooling for the first station are provided. The improved cap has a central button feature in its top panel that can move slightly upward or downward with respect to the remainder of the cap. When a container is filled, liquid Nitrogen is added just before the cap is applied. The liquid Nitrogen turns into gas and creates pressure in the container, causing the button to rise. When a consumer opens the cap, the gas is released and the button returns to its normal (down) position, or if pressure is accidentally lost the button returns to its normal (down) position. Thus indicating loss of pressurization and possible resulting spoilage, or will indicate that the container has been open, and may contain only partial product.

Description:
RELATED APPLICATION 
   This application is related to U.S. Provisional patent application Ser. No. 60/501,374 filed 9 Sep. 2003, entitled PRESSURE INDICATING FEATURE FOR REPLACEABLE CONTAINER CAPS, the entire disclosure of which is incorporated herein by reference. 

   BACKGROUND OF THE INVENTION 
   U.S. Pat. No. 6,015,062, assigned to the assignee of this application, Dayton Systems Group, Inc., discloses closure construction 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. The inventions disclosed in that U.S. Patent and in related Published International Application No. PCT/US01/06046 entitled DOME FORMING SYSTEM , filed 27 Feb. 2002 by said Assignee and published 6 Sep. 2002 [WO 02/068278 A2], and in Published International Application No. PCT/US01/49392 published 27 Jun. 2002 [WO 02/49787 A1], and in Published International Application No. PCT/US2004/028123 entitled CONTAINER END FORMING SYSTEM, filed 30 Aug. 2004 by said Assignee, published 10 Mar. 2005 [WO 2005/021388 A2], provides a unique and versatile container for fluids, e.g. liquid or fluent materials, wherein various standard can bodies are provided with an end including a neck with a pour opening, a thread lug formation on the neck below the pour opening, together with a reclosable cap having a lug formation which can interlock with the thread lug formation on the neck and including a seal surrounding the pour opening, and capable of maintaining product under pressure or vacuum. The subject matter of those three Published International Applications is hereby incorporated by reference, under the provisions of 37 C.F.R. § 1.57(d) 
   In particular, the above identified Published International applications disclose systems for producing lugged cap members, of the type to which the present invention pertains, in a single apparatus, e.g. a press or presses fitted with appropriate tooling, which is capable of precise high speed operation to achieve acceptable commercial production of the cap. 
   SUMMARY OF THE INVENTION 
   When it is desired to utilize the features provided by this invention, a coin ring is used to coin the metal of the cap central portion in a band of relatively narrow width and of significantly less diameter than the cap itself. This creates slack metal from down in the near-center area of the panel, and results in an ‘oil can’ configuration, which responds to the increased internal pressure upon filling and closing by causing the central area to “click” or snap to an extended (outward) position. When the container is opened, internal pressure is released and the central area returns to its state before filling. In the meantime, if internal pressure is lowered sufficiently (e.g. below a predetermined value) or released, the central area of the cap will snap (with an audible click) to indicate the internal pressure has been compromised or lost. The invention thus provides a unique indicator for signaling loss of pressure in a filled and un-opened pressurized container, and also provides an indicator that the container cap has been opened and some of the contents may be removed, or (in the case of beverage contents) at least partially consumed. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a transverse cross-sectional view of a cap provided by the invention; 
       FIG. 2  is a bottom view of the cap shown in  FIG. 1 ; 
       FIG. 3  is a cross-section view of the first station tools in open position; 
       FIG. 4  is a cross-section view of the first station tools in closed position; 
       FIG. 5  is an enlarged segmental cross-section view illustrating the first station upper and lower tools in an almost closed position, showing the precisely defined gap wherein the cap top panel is formed. 
   

   DESCRIPTION OF PREFERRED EMBODIMENT 
   Details of the two station progressive tooling in a cap making press and associated transfer apparatus are disclosed in the published International application PCT/US01/49392 identified above. The present invention relates to different and unique tooling for the first station(s) of such an apparatus, and the uniqueness of the cap so produced.  FIGS. 1 and 2  show such a cap  11  which includes a top panel  12  with a depressed center section  12 A, a peripheral side wall  13 , and a curled rim  14 , together with a plurality of cap lugs  15  which are formed in a second station (not shown herein). 
   A coil or sheets of metal material M, typically Aluminum or thin cold rolled steel, which may have on its upper surface appropriate patterns of lithographed materials for the exterior of each cap  11 , are fed centrally into the first station(s) by appropriate feeding mechanism of known construction. Sheet feed mechanism which moves the material in step-wise fashion, synchronized to the press strokes, along the feed path indicated by arrow N in  FIG. 3 . Feeding metal M from a coil into the first stations is a satisfactory operation. However, using sheets facilitates the application of appropriate (and different) exterior appearance on the caps. 
   The first station tools comprise an upper or blank punch tool  45  ( FIG. 3 &amp; 4 ) having a larger upper portion  46  with an exterior diameter  47 , and a recess  48  adjacent its top. The lower portion  50  of blank punch  45  has a smaller diameter  51  which terminates, at its bottom, as the forming or blanking edge  52  of blank punch  45 . The cylindrical recess  48  in the top of blank punch  45  contains the piston head  55  of a knock-out member  58  which can reciprocate vertically within the blank punch (compare Figs  3  &amp;  4 ). The lower edge of knock-out member  58  is shaped to form the outer edge of the cap, as further described. 
   An upper cavity within piston head  55  receives the head of threaded suspension rod  59  which descends into the lower cavity  62  within blank punch  45 . An upper coining tool  60  is fitted to rod  59 , and may be adjusted vertically, to locate the coining ring  61  ( FIG. 5 ) and the form insert (which is intended to press against but not deform the center of panel  12 A) precisely with respect to the bottom dead center (BDC) location of the upper tooling. A gas spring (or other constant pressure device)  64  is supported above the blank punch tool  45 , and its piston  65  descends partially into recess  54  pressing against piston head  55  to provide a predetermined resistance force against knock-out member  58 . 
   The lower tooling of the first station(s) comprises compound lower tooling including a cylindrical base or die ring  70  with an inner diameter that receives a lower draw pad  71 . During the initial operation of the first station tools, with the lithographed patterns (if present) 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  passing through cut edge ring  72  on top of lower die ring  70 . On the continuation of the down stroke, the lower or forming edge  75  of blank punch  45  moves the cap material about the upper configured edge of draw punch  77 , with the material of the disc being carried downward between the exterior side of draw punch  77  and the interior of blank punch  45 . These tools cooperate such that the blank is drawn into a cup shaped cap part (see upper portion of cup in  FIG. 1 ), with the edge of the part extending slightly below the lower edge of the draw punch  77  (see  FIG. 4 &amp;5 ), when the press tooling reaches its bottom dead center BDC location. 
   At that location (the bottom of the press stroke) the upper coining tool  60  has descended to adjacent the lower coining tool  80  which is fitted into a cavity  82  within the top of a draw punch  77 . The adjustable screws  83  and  84  provide for precise positioning of the draw punch and lower coining tool  80 . When these coining tools  60  &amp;  80  engage the central panel of the cup part between them, they form the depressed panel shape  12 A into the cap top panel  12 , including the surrounding centered coined band B ( FIGS. 1 &amp; 2 ). The central portion of the panel  12 A is depressed as shown in  FIG. 1 . 
     FIG. 5  illustrates the coining tools  60  and  80  slightly apart, and the space between them represents the cross-section of the cap&#39;s upper panel and coined ring, where these tools are more closely spaced and the form insert within the upper coining tool  60  is touching the center of the cap panel  12 A. coin ring is used to coin the metal of the cap central portion in a band of relatively narrow width and of significantly lesser diameter than the cap itself. This creates slack metal from down in the near-center area of the panel, and results in an ‘oil can’ configuration, which responds to the increased internal pressure upon filling and closing by causing the central area to “click” or snap to an extended (outward) position. When the container is opened, internal pressure is released and the central area returns to its state before filling. In the meantime, if internal pressure is lowered sufficiently (e.g. below a predetermined value) or released, the central area of the cap will snap inward (with an audible click) to indicate the internal pressure has been compromised or lost. The coining ring  61  squeezes and deforms the metal in the cap along the coined band B to a cross-sectional thickness less than adjacent portions of the top panel, i.e., less than the remainder of the cap top panel  12  ( FIG. 5 ). Thus, the coined band B segregates the central portion  12 A of the panel from the remainder of the cap top panel  12 . 
   On the press up stroke draw pad  71 , at the inner upper edge of which the lower curl ring  85  is formed, raises under spring pressure with the blank punch  45 . That pressure is provided by rods  88  which extend upward through the lower tooling support plates and against the lower portion of draw pad  71 . Fluid pressure from a suitable source (not shown) acts against pistons  89  at the lower ends of rods  88  to provide the effect of a lower ‘gas spring’. The bottom edge of the cap wall is curled outward into the cavity of curl ring  85  at the upper inner edge of draw pad  71 , completing a formed cap  11  with an outward curled rim  15 . 
   The formed cap in the first station, which is in the nature in an inverted cup, is biased against the upper forming die by a first air stream introduced through passage  50  into the cap as the first station tooling opens, and causes the cap to follow upward against the bottom of the punch  45 . As explained in published International Application (Ser. No. PTC/US01/49392, of), during the upward travel of the cap, a second air stream is initiated in a direction across the upper fist station tooling toward a transfer chute (not shown) and is at its full power when punch  45  (with a cap  11  held thereto by the upward directed first air stream) traverses the space through which the second air stream is directed. By the time the first station tooling reaches full open at top dead center TDC of a press stroke, the cap has actually been transferred into a second station for formation of the cap lugs. 
   Press Rotation Related to Tooling Function 
   1st Station 
   
       
       0° Top of the Stroke; Top Dead Center 
       140° Material is Blanked; example, 0.0108 inch thick aluminum 
       180° Form &amp; draw complete; BDC; Cap Overall Height ˜0.585 inch 
       190° Cap Curl complete; Overall Height is ˜0.585 inch; ID is ˜1.630 in.; coined band is ˜0.750 inch in diameter &amp; ˜0.002-0.003 inch thick &amp; 0.012-0.015 inch wide 
       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 to a second station 
     
  
   Cap Indicator 
   The cap provided by this invention may be used with a container initially filled with (for example) a liquid into which a small charge of liquid Nitrogen is introduced at the end of a filling, just before such cap as herein described is applied to the container. That charge will change into gaseous state and the container and its contents will be internally pressurized. This action causes the cap to snap or ‘click’ outward, and to remain in that state until the container is first opened. Then, the internal pressure is relieved and the cap will snap in a reverse manner. The visible change in shape of the cap&#39;s top panel will signal that the container has been opened (or perhaps has leaked), and additionally the audible ‘click’ sound will provide a further signal. 
   While the methods herein described, and the forms of apparatus for carrying these methods into effect, constitute preferred embodiments of this invention, it is to be understood that the invention is not limited to these precise methods and forms 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.