US3715050A

US3715050A - Full panel easy open end

Info

Publication number: US3715050A
Application number: US00118807A
Authority: US
Inventors: R Batchelar; C Heinle
Original assignee: American Can Co
Current assignee: Rexam Beverage Can Co
Priority date: 1971-02-25
Filing date: 1971-02-25
Publication date: 1973-02-06
Anticipated expiration: 1990-02-06
Also published as: AU3439071A; AU459756B2; IT957524B; JPS5234995B1; CH533041A; GB1365948A; ES172567Y; ES172567U; CA955545A

Abstract

In a full open end closure for a container having a peripheral score defining a removable section in the panel of the end closure, a novel combination of structural features is provided to stiffen the portion of the panel encompassing the peripheral score. The peripheral score is comprised by a pop section at the forward end of the removable section which merges into adjoining start tear sections of the peripheral score, a detach section at the rearward end of the removable section which merges into adjoining minimum tear sections of the peripheral score, and full diameter tear sections at the sides of the removable section which merge into adjoining start tear and minimum tear sections. The end panel also has a hinge score adjacent to the pop section of the peripheral score and a securement for attaching an opening tab to the removable section of the panel, the attachment being positioned between the peripheral score and the hinge score. The novel structural features in the panel are comprised by an inner score in the removable section which runs substantially parallel to the peripheral score, has a depth shallower than that of the peripheral score, and adjoins and merges at its ends into the ends of the hinge score, and stiffening means in the removable section in the form of a ridgelike feature projecting outwardly from the removable section between the peripheral and inner scores both at the forward and rearward ends of the removable section. The novel combination of the inner score with the stiffening means provide a line along the inner score about which the central portion of the removable section is allowed to flex when subjected to forces directed against the removable section to thereby reduce the susceptibility of the peripheral score to abuse and premature fracture which would occur if the removable section should flex on a line along the peripheral score.

Description

United States Patent Batchelar et al.

Primary Examiner-George T. Hall Attorney-Robert P. Auber, George P. Ziehmer, Leonard R. Kohan and John R. Flanagan [57] ABSTRACT In a full open end closure for a container having a peripheral score defining a removable section in the panel of the end closure, a novel combination of structural features is provided to stiffen the portion of the panel encompassing the peripheral score. The

peripheral score is comprised by a pop section at the forward end of the removable section which merges into adjoining start tear sections of the peripheral 7 score, a detach section at the rearward end of the removable section which merges into adjoining minimum tear sections of the peripheral score, and full diameter tear sections at the sides of the removable section which merge into adjoining start tear and minimum tear sections. The end panel also has a hinge score adjacent to the pop section of the peripheral score and a securement for attaching an opening tab to the removable section of the panel, the attachment being positioned between the peripheral score and the hinge score. The novel structural features in the panel are comprised by an inner score in the removable section which runs substantially parallel to the peripheral score, has a depth shallower than that of the peripheral score, and adjoins and merges at its ends into the ends of the hinge score, and stiffening means in the removable section in the form of a ridgelike feature projecting outwardly from the removable section between the peripheral and inner scores both at the forward and rearward ends of the removable section. The novel combination of the inner score with the stiffening means provide a line along the inner score about which the central portion of the removable section is allowed to flex when subjected. to forces directed against the removable section to thereby reduce the susceptibility of the peripheral score to abuse and premature fracture which'would occur if the removable section should flex on'a line along the peripheral score.

6 Claims, 5 Drawing Figures Feb. 6, 1973 FULL PANEL EASY OPEN END BACKGROUND OF THE INVENTION One of the more important recent developments in the can making industry is the trend toward scored self-opening cans which can be opened by means of an opening tab which is secured to the can. The most common form of such a can is the beer and beverage can in which the product is dispensed through a comparatively small hole which is opened in the can end when the opening tab is lifted to tear away a small removable section which is defined by a score line in the end panel.

Another form is the full-open can in which a score is impressed in the end panel proximate to the periphery of the end panel to permit its complete removal. Such full-open cans are suitable for use in the packaging of solid or chunky products such as processed or frozen meats, fishes, vegetables and fruits, and frozen juices which are to be removed from the container in their entirety. They are also desirable for the packaging of products which are customarily removed by insertion of an instrument or the fingers of the user into the container. Examples of such products are candy, shelled nuts, meats and coffee.

In the area of scored self-opening cans, any score defining a removablesection in the end panel constitutes a line of metal weakness in the end panel.

When the removable section includes a large surface area of the end panel, as in the case of a full-open end where it covers substantially the whole endpanel, undesirable and uncontrollable forces directed against the removable section tend to cause it to flex, relative to the remainder of the end panel, along this line of metal weakness, the peripheral score. Such forces arise in the case of containers for processed foods. During the cooking of food in the container, internal pressures bulge the removable section and thereby cause the removable section to flex along the peripheral score. Later when the food cools and a partial vacuum condition is created within the container, the removable section flips to a concave position. Again, the removable section flexes along the peripheral score. The flexing of the removable section along the peripheral score places a severe strain on the weakened residual metal beneath the score, making it susceptible to abuse, leakage and premature fracture.

The present invention provides a novel combination of structural features on a full open end panel which overcomes the problem of the removable panel flexing along the peripheral score and, thereby, reduces the susceptibility of the peripheral score to abuse and premature fracture. This novel combination is comprised by an inner score impressed in the removable section of the end panel substantially parallel to the peripheral score and a ridge-like feature projecting outwardly from the removable section between the peripheral and inner scores at the forward and rearward ends of the removable section. The ends of the inner score novelly merge with the ends of the adjoining hinge score. The ridge-like features stiffen the metal between the peripheral and inner scores at the forward and rearward ends of the removable section and thereby resists the flexing of the removable section along the peripheral score. The inner score, which is shallower than the peripheral score, promotes and provides a different flex point for the removable: section and, in such manner, contributes to the prevention of flexing along the peripheral score.

SUMMARY OF THE INVENTION A full open end closure for a container, having a peripheral score defining a removable section in the end panel and a hinge score adjacent the peripheral score at the forward end of the removable section, has an inner score which is shallower than the peripheral score and runs substantially parallel to the peripheral score with the ends of the inner score adjoining and merging into the ends of the hinge score. Also, the end closure has a ridge-like feature which projects outwardly from the removable section between the peripheral and inner scores at the forward and rearward ends of the removable section. This novel combination of an inner score and ridge-like features stiffens the metal of the end panel between the inner and peripheral scores to resist the flexing of the removable section along the peripheral score and, instead, permits the removable section to flex along the inner score.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a plan view of an end closure made in accordance with the present inventionj FIG. 2 is an enlarged, fragmentary view of the forward end of the removable section of the end closure shown in FIG. 1 with the opening tab omitted;

FIG. 3 is an enlarged, fragmentary view partially in section taken substantially along lime 3-3 of FIG. 1;

FIG. 4 is an enlarged, fragmentary view partially in section taken substantially along "line 44 of FIG. 1; and

FIG. 5 is a schematic illustration of the various sections of the peripheral score of the end closure shown in FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT An end closure, generally designated 10, embodying the present invention is shown in FIGS. 1 and 3. Preferably, it is rectangular and made of aluminum, tinplate, or other rupturable material. The end'closurel0 includes a peripheral outwardly extending curled flange 12 which may be interfolded with the end flange of a can body (not shown) to form an end seam (not shown). The peripheral flange 12 merges into an annular countersink wall 14 which extends downwardly from the peripheral flange 12 to animperforate central end panel 16.

Impressed in the top surface of the central end panel 16 is a score, generally designated 18, which defines a removable section 20 which becomes detached from the end closure 10 when the score 18 is completely ruptured. The score 18 is close to the: periphery of the central end panel 16 so that it defines a removable section 20 which is almost as large as the central end panel 16. The peripheral score 18, as schematically illustrated in FIG. 5, is comprised by a pop section 22 at the forward end of the removable section 20 which merges into adjoining start tear sections 24. The rearward ends of the start tear sections 24 merge into adjoining substantially full diameter tear sections 26. The rearward ends of the full diameter tear sections 26 merge into adjoining minimum tear sections 28 whose rearward ends merge into a detach section 30 at the rearward end of the removable section 20.

In order to provide means for rupturing the peripheral score 18, an opening tab 32 is fastened to the removable section 20 at a location adjacent to the pop section 22 of the peripheral score 18 by a hollow rivet 34 formed integral with the removable section 20. The opening tab 32 includes a web portion 36 through which the rivet 34 passes, a handle portion 38 rearwardly of the web portion 36 and a nose portion 40 forwardly of the web portion 36 which is urged downwardly when the handle portion 38 is raised to initiate pop or rupture of the pop section 22 of the peripheral score 18.

The removable section 20 has a mustache or hinge score, generally designated 42, impressed therein having a curved central portion 44 which passes immediately behind the rivet 34 which portion 44 initially ruptures during the first stage of the upward rock of the opening tab 32 to allow a venting of the container thereby equalizing the internal pressure of the container and the atmosphere pressure on the top of the central end panel 16. The removable section 20 further has several parallel and downwardly projecting beads 46 formed therein which promote the formation of a bend in the removable section 20 in a direction which is generally perpendicular to the direction in which the opening tab 32 is moved, to facilitate the progressive rupture of the peripheral score 18. The advantages of providing the mustache score 42 are disclosed in greater detail in the application for Letters Patent, Ser. No. 728,518, now U.S. Pat. No., 3,544,025, and do not form any part of the present invention. The advantages of providing the beads 46 are disclosed in greater detail in U.S. Pat. No. 3,478,918 which issued on Nov. 18, 1969 and do not form any part of the present invention.

As shown in FIGS. 1, 2 and 3, the end closure is novelly provided with an inner score, generally designated 48, impressed in the removable section which runs generally parallel to the peripheral score 18, having a depth shallower than that of the peripheral score 18 and which may be equal to that of the hinge score 42, and ridge-like features, generally designated 50, which project outwardly from the removable section 20 between the peripheral score 18 and the inner score 48 at the forward and rearward ends of the removable section 20. The ends 52 of the inner score 48 novelly merge into the adjoining ends 54 of the hinge score 42 at a location, generally designated, 56. The ridge-like features 50 stiffen the metal of the removable section 20 between the peripheral score 18 and the inner score 48 at the forward and rearward ends of the removable section 20 and thereby resists the flexing of the removable section 20 along the peripheral score 18. Further, the inner score 48 contributes to the ability of the ridge-like features 50 to stiffen the metal of the removable section 20 between the peripheral score 18 and the inner score 48 by providing a different flex point for the removable section 20, that being along the inner score 48. The ridgelike stiffening features 50 are formed from the excess metal in the removable section 20 which is provided during the formation of the peripheral score 18 and the inner'score 48.

While the inner score 48 is described above as running generally parallel to the peripheral score, as shown in FIGS. 1, 3 and 4 the center-to-center distance between the

scores

18, 48 is greater at the forward and rearward ends ofthe removable section 20 than at the sides of the removable section. The provision of an inner score per se, which is shallower than the peripheral score, for the purpose of anti-fracture is disclosed by U.S. Pat. No. 3,406,866 which issued on Oct. 22, 1968 and does not form any part of the present invention. As disclosed in the aforementioned patent, the practical range of the center-to-center spacing between the peripheral score and the inner score, in order for the inner score to function as an anti-fracture score, is from 0.050 inch to 0.125 inch with the optimum spacing being on the order of 0.080 inch. In the present invention, the center-to-center spacing between the peripheral score 18 and the inner score 48 at the forward and rearward ends of the removable section 20 is above the aforementioned range, or,.greater than 0.125 inch. Therefore the inner score 48 of the present invention, at the forward and rearward ends of the removable section 20, does not function as an anti-fracture score. In one practical example of an end closure incorporating the present invention, the center-to-center spacing between the peripheral score 18 and the inner score 48, at the forward and rearward ends of the removable section 20, is about 0.194 inch. In this example, the hinge and inner scores have equal residual metal thicknesses of about 0.005 inch, which thickness is generally about 0.001 inch greater than the residual metal thickness of the peripheral score, that being 0.004 inch.

It is thought that the invention and many of its attendant advantages will be understood from the foregoing description and it will be apparent that various changes may be made in the form, construction'and arrangement of the partswithout departing from the spirit and scope of the invention or sacrificing all of its material advantages, the form hereinbefore described being merely a preferred embodiment thereof.

We claim:

1. In a full open container panel having a peripheral score defining a removable section in said panel, said score being comprised by a pop section at the forward end of said removable section which merges into adjoining start tear sections of said score, a detach section at the rearward end of said removable section which merges into adjoining minimum tear sections of said score, and full diameter tear sections at the sides of said removable section which adjoin and merge into the start tear and minimum tear sections, a hinge score adjacent to said pop section of said peripheral score, and a securement for attaching an opening tab to said removable section positioned between said peripheral score and said hinge score, the improvement comprismg:

an inner score in said removable panel running generally parallel to said peripheral score and having a depth shallower than said peripheral score and wherein the center-to-center distance between said peripheral and inner scores at the forward and rearward ends of said removable section is greater than 0.125 inch; and

stiffening means in said removable section between against said removable section to thereby reduce the said peripheral and inner scores at the forward and susceptibility of said peripheral score to abuse and prerearward ends of said section, said stiffening mature fracture. means comprising a r dg f atu at both the 4. The full open container panel of claim 3 wherein P 'f ends of Said fmovable 5 said stiffening means comprises a ridge-like feature at P l outwardly from 531d removable both the forward and rearward ends of said removable Section and fofmed f m excfiss metal m 531d section projecting outwardly from said removable secremovable Seem) whlch provided by the forma' tion and formed from excess metal in said removable tion i peripheralandinnir section which is provided by the formation of' said 2. The fu open container pane o c arm 1 wherein Peripheral and inner scores :5 9:" g i g z g 33 fg g i. 5. The full open container panel of claim 4 wherein a 1 C res a e Orwar an re wa en 8 o the center-to-center distance between said peripheral said removable section is greater than 0.125 inch.

3 The fun 0 en container and of claim 1 wherein and inner scores at the forward and rearward ends of i p p said removable section is greater than 0.125 inch.

said inner score and adjacently positioned stiffening l5 means at the forward and rearward ends of said fun 9 contamer f f of clam l Wherem removable section cooperate to provide a line along the ends 9 Score adjom and merge the said inner score about which said removable section is ends of Sand hmge Score allowed to flex when subjected to forces directed

Claims

1. In a full open container panel having a peripheral score defining a removable section in said panel, said score being comprised by a pop section at the forward end of said removable section which merges into adjoining start tear sections of said score, a detach section at the rearward end of said removable section which merges into adjoining minimum tear sections of said score, and full diameter tear sections at the sides of said removable section which adjoin and merge into the start tear and minimum tear sections, a hinge score adjacent to said pop section of said peripheral score, and a securement for attaching an opening tab to said removable section positioned between said peripheral score and said hinge score, the improvement comprising: an inner score in said removable panel running generally parallel to said peripheral score and having a depth shallower than said peripheral score and wherein the center-to-center distance between said peripheral and inner scores at the forward and rearward ends of said removable section is greater than 0.125 inch; and stiffening means in said removable section between said peripheral and inner scores at the forward and rearward ends of said section, said stiffening means comprising a ridge-like feature at both the forward and rearward ends of said removable section projecting outwardly from said removable section and formed from excess metal in said removable section which is provided by the formation of said peripheral and inner scoreS.

2. The full open container panel of claim 1 wherein the center-to-center distance between said peripheral and inner scores at the forward and rearward ends of said removable section is greater than 0.125 inch.

3. The full open container panel of claim 1 wherein said inner score and adjacently positioned stiffening means at the forward and rearward ends of said removable section cooperate to provide a line along said inner score about which said removable section is allowed to flex when subjected to forces directed against said removable section to thereby reduce the susceptibility of said peripheral score to abuse and premature fracture.

4. The full open container panel of claim 3 wherein said stiffening means comprises a ridge-like feature at both the forward and rearward ends of said removable section projecting outwardly from said removable section and formed from excess metal in said removable section which is provided by the formation of said peripheral and inner scores.

5. The full open container panel of claim 4 wherein the center-to-center distance between said peripheral and inner scores at the forward and rearward ends of said removable section is greater than 0.125 inch.