IL31442A - An end wall construction for a metal can - Google Patents

Description

nana nosip '.ns' n ^a n maD An end wall construction for a metal can - 2 - 31442/2 Ψ' Thia invention relates to a fully opening metal container of the kind having an upper wall in which a continuous marginal score line defines a removable end panel to which is secured a pull tab whose normal manipulation permits the end panel to be peeled back and removed.

Conventional containers of this kind suffer from a number of deficiencies such as a tendency for the pull tab to tear away from the end panel during manipulation of the^tab, usually requiring a relatively large pulling force to be exerted in order to establish an initial tear in the score line, resistance to readily tearing the end panel from the initial tear progressiveJLy along the score line, etc. It is therefore an objeot of the present invention to provide a new and improved metal container of the kind described above wherein the above referred to deficiencies are substantially reduced or overcome.

According to the present invention, there is provided a fully opening metal container of the kind in which a continuous marginal outer score line defines a removable end panel in an end wall of the container and in which a ring pull tab means is secured by a rivet means to the end panel, the container comprising a nose formed at one end of the tab means for initiating rupture of the score line, the hose being normally located immediately above and extending across and beyond the outer score line, the pull tab means being bendable at a region between, and spaced from, the nose and the rivet means, and the end panel being bendable at a region closer to the rivet means than the pull tab - 3 - 31442/2 bend region, the arrangement being such that when the container is opened b exerting on the tab means a pull in a direction substantially normal to the plane of the end panel, the nose wipes and retracts across the outer score line and forms an indentation in the end panel immediately below the nose, the indentation extending inwardly from the outer score line at the location where the end wall is punctured by the nose* Embodiments of the invention are illustrated by way of example in the accompanying drawings, wherei : Fig. 1 of the drawings is a top plan view of one embodiment of a metal can according to the invention; Fig. 2 is a vertical section on a larger scale taken on the line a-a? in Fig. 1; Fig. 3 is a perspective view of the can shown in Figs. 1 and 2, with parts broken away, showing the initial stage of manipulating an improved ring pull tab for end panel removal; Fig. 4 is a perspective view similar to Fig. 3 showing a later stage in the operation of tearing out the end panel; Fig. 5 is a fragmentary sectional view on a further enlarged scale of a portion of Fig. 2 Illustrating the ring pull tab in its normal position prior to manipulation for end panel removal; Fig. 6 is a view similar to a portion of Fig. 5 but showing the ring pull tab moved tqa position similar - 4 - 31442/2 to that shown In Fig. 3 in the initial stage of removing the end panel; Fig. 7 is a view similar to Figs. 5 and 6 but showing the relative positions of the parts as the end panel has been peeled further from the end wall member; Fig. 8 is a view on a smaller soale showing the end panel and pull tab a ter the end panel has been removed completely from the can; Fig. 9 is a perspective view similar to Figs. 3 and 4 showing the removed end panel and pull tab illustrated in Fig. 8; Fig. 10 is a view looking upwards in the direction of the arrows b-b in Fig. 6, illustrating the shape of the end panel during the initial stage of end panel removal; Fig. 11 is a fragmentary sectional view taken on the line c-c in Fig. 9 illustrating the relation of certain of the parts to one another after the removal of the end panel; Fig. 12 Is an enlarged top plan view of the improved ring pull tab structure Fig. 13 is a side view looking towards the left-hand end of Fig. 12; Fig. 14 is a fragmentary sectional view looking in the direction of the arrows d-d in Fig. 12; Fig. 15 is a sectional view taken along the line e-e in Fig. 12; - 5 - 31442/2 Fig. 16 is a fragmentary sectional view taken along the line f-f in Fi t 12; Fig. 17 i3 a fragmentary sectional view taken along the line g-g in Fig. 12; Fig. 18 is a fragmentary view lookin in the direction of the arrows h-h in Fig. 12; Fig. 19 is a top plan view similar to Fig. 1 of a smaller sized can provided with a fully opening container end wail structure according to the invention; Fig. 20 is a bottom plan view of the container illustrated in Fig. 19; Fig; 21 is a view similar to Fig. 19 with parts broken away illustrating the relationship between the can $op and the can bottom wall structures; Fig. 22 is a vertical section looking in tho dlr ·.·,. ootion of tho arrows i-i in Fig. 1Q illustrating—two- caae-stacked one on top of tho other; F g! 23 o an onHarged fragmentary oootional view of a portion of Fig. 21, looking in tho direction of the arrows) j-j in Fig. 21; Fig. 24 is an enlarged fragmont&ry sectional view looking in the- direotlon of the arrowo k k in Figt 21|—andr 'Fig. 2 is an enlarged sectional view looking I the direction of the arrowo 11 in Fig. 21.

Similar numerals refer to similar parts throughout the drawings.

The invention is illustrated typically in Figs. - 6 - 31442/2 1 to 18 aa applied to a can size which is larger than the 1 can illuotrated in Pigs. 19 to 24, container or can, generally indicated at 1, is of generally conventional construction including a cup-shaped body providing side walls 2 and a bottom wall 3· T e can body side walls 2 are closed at the upper end of the can by an improved can end wall structure indicated generally at 4 secured to the side walls 2 by a conventional double seam 5· The end wall structure has a portion recessed at 6 with respect to the double seam 5 (Figs. 2 and 5). T e recessed wall portion 6 is formed with a score line 7 immediately adjacent to the double seam 5 and the upper end of the can side wall 2, the score line 7 thus defining an end panel 8. The end panel 8 is completely removable from the remainder of the end wall structure 4 when severed along the score line 7 to provide a full opening at the top of the can 1* The improved end wall structure 4 also includes an improved pull tab structure generally indicated at 9· The ring pull tab 9 (Pigs. 12-18) is formed of sheet metal of somewhat heavier gauge than the sheet metal from which the end wall 4 is formed. The members 4 and 9 are preferably, but not necessarily, formed of aluminium.

The ring pull tab 9 has a main or top wall 10, and one end 11 of the wall 10 is reduced in width by curved portions 12.

A generally circularly-shaped recess 13 is formed in the one end 11 with a connected channel portion 14 extending from the recess 13 to tie outer edge 15 of the one end 11 of the - 7 - 31442/2 top wall 10. The bottom wall 16 of the recess 13 is in the same plane as the bottom wall 17 of the channel 14» and the walls 16 and 17 are spaced below the top wall 10. A pair of louvres 18 are struck upwards from the top wall 10 outside the right-hand end of the recess 13 (Pig. 12) for the purpose to be described below.

A ring opening 19 is formed in the other or opposite end 20 of the top wall 10 of the member 9» so that the recess 13 is located in the one end ·¾¾ and the opening 19 is located in the opposite end 20 of the member 9. The ring opening 19 forms a finger hole or ring which may be grasped when the member 9 is manipulated. The end 20 of the member 9 is formed with an outer reverse curved bead 21 extending semi-cirularly around the right-hand half of the opening 19 (Fig. 12). The top walV is formed around the periphery of the opening 19 with an inner reverse curved bead 22 circularly continuous in extent. The beads 21 and 22 at the right-hand end 20 of the member 9 form a false wire bead which is generally rounded in cross-section (Fig. 5) as indicated at 23.

The member 9 is provided with straight parallel edges 24 extending between the curved portions 12 at the one end 11 and the semi-circular portion at the opposite end 20 of the top wall 10 of the member 9· The parallel edges 24 and curved end-portions 12 are formed with outer reverse curved beads 25 which are formed as a continuation of the bead 21. - 8 - 31442/2 member 9 is substantially straight at either side of the channel 14 (Fig. 12) and the outer edge 15 is perpendicular to an axis or oentre line (s ch as the section line f-f) passing through the centre of the opening 19 and the centre of the recess 13· The flat wall 17» which is a continuation of the recess bottom wall 16 and forms the botton of the channel 14, has a rounded nose 26 which projects outwardly to the left of the top wall edge 15 (Figs. 5 and 12).

An opening 27 is punched close to the one end 11 of the pull ring 9 generally centrally through -the bottom wall 16 of the recess 13 (Fig. 12) for receiving a rivet 28 to connect the member 9.with the end wall 4· This rivet connection 28 for assembling the members 9 and 4 may be made in a conventional manner, or the fastening may be accomplished as set forth in U.S. Patent Ho. 3,346,948.

The bottom wall 16 of the recess 13 in the member 9 is lanced at 29 with a special slit 29, the shape and location of which are of special importance. The slit 29 (shown in Figs. 1 and 12) includes a semi-circular portion 30 close to the opening 27 and Immediately adjacent to the head of the rivet 28 (Fig. 1). A semi-circular portion 30 is extended by straight portions 31 at either end which diverge outwardly towards the one end 11 of the member 9 (Fig. 12). Diverging straight portions 31 •terminate in small hook-like shapes 32.

The metal in the recessed bottom wall 16 of the member 9 extending between the hook portions 32 provides a hinge-like bend area indicated at 33 (Figs. 6, 7 and 8) alon - 9 - 31442/2" which the member 9 pivots when the rear pull tab 9 is manipulated to open the can.. The outward divergence of the straight portions 31 of the slit 29 provides a maximum length for this hinge area so ae to retain maximum strength for the connection between the member 9 and the portion 16a of the recessed bottom wall 16 within the slit 29 and the surrounding rivet opening 27.

At the same time, the semi-circular lance pprtlon 30 is located as close as possible to the opening 27 so that, whilst sufficient metal la left in the slit bottom wall-portion 16a to provide a strong and stable rivet connection, at the same time, as much recessed bottom wall metal 16 as possible is left to surround the slit 29, thereby retaining stiffness and strength for the portion of the member 9 to the left (Fig. 12) of the opening 19. This stiffness and strength result from the offset flat wall portions provided by the top wall 10 and the recessed bottom wall 16 at the bottom of the recess 13.

The hook-like portions of the curled ends 32 of the lance 29 prevent the metal from tearing outwardly towards the end 11 of the member 9 at the extremities of the straight portions 31 of the slit 29, as the member 9 is bent along the bend area 33· Xt is important, in connection with the new structure, that the member 9 should be very accurately located in a proper position with respect to the end wall 4 when the two members are assembled and the rivet 28 is formed. The straight edges 24 of the member 9 provide aligning edges to be engaged - 10 - 31442/2 by the assembly tools in one direction (horizontally across Fig. 12), and the edges 18a of the louvres 18 (Figs. 12 and 17) provide locator edges engaged by the assembly tools in a vertical direction or perpendicular to the edges 24 of the member 9· The shape and location of the rounded nose 26 at the end of the bottom wall 17 of the channel 14 are important in achieving the objectives of the invention. Firstly, the rounded nose 26 as described should project outwardly to the left of the top wall outer edge 15 (Figs. 5 and 12).

Furthermore, when the member 9 is riveted to the member 4 (Fig. 5), the rounded nose 26 should overlap appreciably the circular score line 7 in the member 4. Finally, the outer curved beads 25 along the curved portions 12 of the one end 11 of the top wall 10 are cut back and relieved as illustrated by the curved edge 34 in Figs. 12, 13, 14 and 18.

The opening of a can provided with the improved ring pull tab member and end wall structure 4 and the progress of the opening operation are illustrated in Figs.3 to 11.

The parts in their normal positions as assembled on a closed can are shown in Fig. 5. The round portion 23 at the right-hand end of the member 9 Is grasped between the thumb and finger of one hand of the user and pulled upwardly towards the position dlagrammatlcally shown in Fig. 6 and also generally in Fig. 3. During pivotal movement of the member 9 from the horizontal position of Fig. to the vertical position of Fig. 6, the metal of the member 9 bends and pivots along - 11 - 31442/2 wipes along the end wall 4 across a portion of the soore line 7 as the rounded nose presses downwardly. This wiping and downward pressing action, because of the location and shape of the rounded nose 26 and of the channel shape 14 from which the rounded nose 26 projects, causes the nose 26 y ' slightly to Indent the end wall metal Inside the score line 7 edge of the indented region 3 » with a minimum of effort required to move the member 9 between the horizontal position of Fig. 5 and the vertical position dlagrammatically illus-trated in Pig. 6.

\ After the initial severing at the outer edge of the Indented region 35» the metal tears quite easily from the ends of the initial severenoe clrcumferentially along the score line 7 in both directions. When the position of the parts generally shown in Pig. 3 is reached, the end wall, metal of the severed portion is curved concavely laterally of the member 9 as Illustrated generally at 36 In the drawings during bending at 37. Meanwhile, vertical pull on the member, continues the tearing action of the end panel 8 along the score line 7 as Illustrated in Figs. 4 and 7 until the, end panel 8 Is completely removed when it has the shape - 12 - 31442/2 generally shown in Figs. 8 and 9. Although the opening action has been described as comprising bending or hinge movement of the member 9 from the horizontal position, and then a vertical pull on the member 9» in actual peration these movements are combined and the vertical pull is exerted while bending and before the vertical position of the member 9 shown diagrammaticall in Fig. 6 is reached. Thus, the concavely curved portion 36 bent about the bend region 37 actually never enters or dips into the interior of the can to the degree shown on an enlarged scale diagrammaticall in Fig. 6.

The end wall 4, which is of thinner gauge sheet metal than the pull tab member 9 bends about the region 37 adjacent to the edge of the rivet 28, a clearance 38 resulting between the bend regions 33 and 37 (Figs. 6 and 7)# The initial retraction of the nose 26 to form the indentation 35 Is followed by further retraction along the top of the end panel 8 away from the severed edge 39 for a considerable distance as indicated at 40 in Fig. 7.

The relieving of the beads 25 as indicated by the curved edges34 at either side of the rounded nose 26 (Figs. 12, 13, 14 and 18), ensures that only the nose 26 is in contact with the end panel 8 during formation of the indentation 35 (Figs. 10 and 11), bending of the member 9 at the region 33 and of the end panel 8 at the region 37, and further retraction of the nose 26 from the severed edge 39 as Indicated at 40. - 13 - 31442/2 In order to assist in initially grasping the right-hand pull ring portion 23 as described, the end wall 4 may be formed with a recess 41 and the right-hand end of the rounded ring portion 23 may be bent upwards slightly as indicated at 42, thus providing easier access to grasp the ring as shown in Fig. 5.

In end wall structures with pull rings intended to tear out an end panel around a score line 7 generally shown in Fig. 1, during the hinging and pulling of the member 9» because of stiffness of metal in the end wall 4» the end wall 4 has a tendency to form convexly upwards in a trough-like manner with the trough extending from left to right from the zone of initial severanoe viewing Pig. 1. This tendency has caused the tearing out operation of the end panel to be difficult. In accordance with the preferred aspect of the invention, this difficulty is eliminated, and the undesirable trough-like formation is inhibited by providing grooves 43 in the end wall. At least a majority of the grooves 4 should preferably be curved with the same curvature. The curvature should preferabl be quite shallow with its maximum point of concavity faoing the rivet 28. A first pair of grooves 43a should preferably extend on either side of the rivet 28.

The grooves 43 have a number of functions. First of all, they facilitate a peeling action (illustrated in Figs. 4, 7, 8 and 9) of the end panel 8 as it is removed from the can. They prevent a dip-down of the end panel 8 at the completion of the operation of tearing the end panel 8 from the can. The also minimise the lift on the flane 44 -14 % 31442/2 (Fig. 7) which Is left on the can structure as the remainder of the end wall after the end panel 8 is torn out. Finally, they strengthen the end wall 4 against retort flexing and flipping up and down of the end wall during cooking of food products within, a sealed can.

The score line 7 along which the end panel 8 is torn when removing the end panel is located substantiall In line with the inside surface 45 of the can side wall 2 (Figs. 5 and 7). A second or inner score line 46 is formed in the' end panel 8 close to, but spaced from, the score line 7·, The inner soore line 46 is shallower than the main or tear score line 7* The inner score line 46 acts to relieve the main score line 7 of movement from flexing incident to changes in relative prossures within, and outside of, the can during heating of a sealed can for processing food therein. Thus, flexing of the can end wall 4 during heating Imparts most of the flexing force to the shallower inner score line 46 which thus relieves the deeper ear score line 7 of forces which might otherwise tend accidentally to f acture the main s core line 7.

The improved structure o the invention is also illustrated for a smaller size can in Figs. 19 to 2^.

The illustrated can also incorporates features separately described and claimed in Paten ^Application No. 41139. - 15 - 31442/2 The illustrated can 46 is of smaller size than that indicated at 1 in Figs 1 and 2. The end wall 47 of the can ' 48, excepting for having a smaller diameter, is very similar to the end wall 4 of the can 1 and has the same Improved ring pull tab structure 9 assembled thereto by a rivet 28.

The same grooves 49 are formed in the end wall 47 to facilitate the peeling action during the removal of the end panel 50 tearing alon the score line 51. The rounded nose 26 of the ring pull tab 9 slightly overlaps the score line 51 in the same manner as described in connection with Figs. 1 to 18. In the structure shown in Figs. 19 to 25, the pull ring recess 52 is formed in the end panel 50 beneath the right-hand end of the ring pull tab 9 n the same relative location with respect to the opening 19 in the pull tab 9 as illustrated in Fig. 1 with respect to the larger sized can 1.

The struoture of the end wall 47 differs from the larger sized end wall 4 in that a plurality of rounded bosses or knobs 53 are formed in the end panel 50 which are located at two corners of a triangle the third corner of which is defined by the nose end 11 of the tab 9. .16 * 31442/2. o¾t-a¾ovo.

The improved construction combines a number of important features and advantages resulting from the shape and location of the slit 29 in the pull tab, from the perpendicular locator means 18a on the pull tab 9 or accurately controlling the location of the rounded nose 26 with respect to the end panel 8, om the shape and location of the rounded nose, from the space 38 between the hinge -17 - 31442/2 peeling for end panel removal ¾rom the relationship between the differential depth double score lines, and from the rounded stacking bosses or knobs 33 and tho bottom wall oorrugationo 55- 57 oooperoting therewitht provides structures which eliminate all of which 'difficulties encouTiterefl with prior devloffBt and rovides structures which achieve the objectives an solve the problems existing in the art in a simple and readily controlled manner* In the foregoing description, certain terms have been used for brevity, olarlty and understanding; but no unnecessary limitations are to be implied therefrom beyond the requirements of the prior art because suoh terms are used for descriptive purposes and are Intended to be broadly construed.

Moreover, the description and illustration of the Invention are by wa of example, and the scope of the invention as defined by the appendant claims is not limited to the exact details shown or described since the features of the inventi'b may be applied to end walls for different sized cans.

Claims (1)

A fully opening container of the kind in whioh a oontinuouo marginal outer line defines a removable end panel in an end ail of the oontainer and in whioh a ring pull tab means is secured by rivet to the end the container comprising a nose formed at one end of the tab means for initiating rupture of the the being located immediately above and extending aoroae and beyond the outer score the pull ta means being bendable at a region and the nose and the rivet and the end panel being bendable at a region closer to the rive means than the pull tab bend the arrangement being when container is opened by exerting on the moana a pull in a direction substantially normal to the plane of the end the nose wipes and retracts aorosa the outer score line and forms an indentation in the end panel immediately below the the indentation extending inwardly from the outer score line at the location where the end wall punctured by the A oontainer na in Claim 1 in whioh a series of spaced curved grooves are formed in tho end panel presenting their oonoavity toward the location of the rivet means and the oontainer as claimed in Claim 2 in whioh a pair of grooves are arranged to extend one on eaoh side of the rivet container as claimed in any of Claims 1 to 3 in whioh the pull tab is of sheet metal with a top a recess having a bottom wall and an outer edge formed in one end of the top a pull ring opening formed in tho 19 othor of tho top a channel wall formed in tho top di from the to tho one top vail bottom of tho and channel in tho tho top and tho terminating in tho Λ container claimed in which tho bottom formed with opening through tho rivet tho val being formed a around tho the olit a circular olit portion to the rivet than to tho outer recces outwardly straight olit portions and tho elit portion tho one top wall end in inwardly curled and which the the portiono the pull tab bend A rxa in any of 1 to in which the tab to tho end panel by a rivot at one end of tho tab in which a pull in tho her of the tab in which tho tab is formed vith spaced parallel the one and otho in which louvre are in the pull tab having locator means extending perpendicularly to the parallel container in any of Claims 1 to 6 in which a oontinuoua innor io in the end panel from the outer which tho outer lo to greater depth than innor 20 A container claimed in any of 1 to 7 in which tab and the end wall are both formed of sheet and in which the pull tab is formod of oheet netal than the end A container as in

1. Claim 1 substantially as described with reference to tho accompanying For the Applicants PARTNERS insufficientOCRQuality