US3905513A

US3905513A - Sealant for pushdown gate in a can lid

Info

Publication number: US3905513A
Application number: US370924A
Authority: US
Inventors: Gerald B Klein
Original assignee: Individual
Current assignee: Individual
Priority date: 1973-06-18
Filing date: 1973-06-18
Publication date: 1975-09-16
Anticipated expiration: 1992-09-16

Abstract

A sealing arrangement for a pushdown gate in a can lid of the type where the gate is defined by a score line in the face of the lid which is torn and severed when the gate is pushed into the can. This score line outline of the gate is located in an indentation in the surface of the can and at one point, the score line is lanced to facilitate its tearing action. The gate structure in the can lid further includes a lapping portion between the gate itself and the can lid, either with the gate underlying an aperture in the lid or forming an underlying tab which surrounds the lanced opening. A settable sealer-filler may be applied to the lid at the indentation as a liquid to flow between the lap and into the lanced opening. Thereafter, when the sealer-filler sets, it will effectively harden to produce a positive seal at the lanced opening.

Description

United States Patent 1191 Klein 1451 Sept. 16, 1975 SEALANT FOR PUSHDOWN GATE IN A CAN LID [76] Inventor: Gerald B. Klein, 13451 Stuart Ct.,

[52] US. Cl 220/268; 220/265 [51] Int. Cl. B65D 43/02 [58] Field of Search 220/27, 45, 46 R, 46 MS,

[56] References Cited UNITED STATES PATENTS 178,544 6/1876 Merrill 220/45 3,794,206 2/1974 De Line 220/48 Primary ExaminerWilliam l; Price Assistant ExaminerRo E. Hart Attorney, Agent, or Firm-Van Valkenburgh, Lowe & Law

[ 57 ABSTRACT A sealing arrangement for a pushdown gate in a can lid of the type where the gate is defined by a score line in the face of the lid which is torn and severed when the gate is pushed into the can. This score line outline of the gate is located in an indentation in the surface of the can and at one point, the score line is lanced to facilitate its tean'ng action. The gate structure in the can lid further includes a lapping portion between the gate itself and the can lid, either with the gate underlying an aperture in the lid or forming an underlying tab which surrounds the lanced opening. A settable sealer- 3,298,87O 1/1967 Sabatino.... 220/45 filler may be applied to the lid at the indentation as a 3,334,775 8/1967 Klein 220/48 liquid to flow between the ,lap and into the lanced 3,485,411 12/1969 Brown 220/48 opening. Thereafter, when the sealer-filler sets, it will 3,628,688 1 71 aggard-m. 220/46 R effectively harden to produce a positive seal at the 3,630,408 12/1971 Elser... 220 27 lanced Opening 3,760,752 9/1973 Geiger 220/27 3,779,417 12/1973 Klein 220/48 7 Claims, 29 Drawing Figures L/ G i PATENIEU @975 3805513 Fig. IO

PATEIHEU 1 975 nan g 1 7 i 7 1 '17 z 2 T 50 5o 53 Fig. 16 Fig. 17

765 L") 7 6" mg Fig. I8 Fig. I9

SEALANT FOR PUSI-IDOWN GATE IN A CAN LID This invention relates to can lids having gates in the surfaces of the lids which are pushed downwardly into the cans to open them, and more particularly to means and materials for sealing such gates until they are opened.

The invention may be used with gated can lids wherein the gate is integral with the lid and is formed at an opening or aperture in the can lid beneath an underfolded, interconnecting spacer strip about this aperture, of the type set forth in the patent issued to myself and Kenneth E. Harper, U.S. Pat. No. 3,334,775, on Aug. 8, 1967. The invention may also be applied to similar gated can lids where portions of the gate and lid lap each other at the section to be sealed, as hereinafter set forth.

To form a push-down gate in a canv lid,- an important step is to cut a score line to define the outline of the gate, leaving an uncut hinge portion so that the gate may separate from the lid and swing about the hinge portion as it is pushed downwardly. The present invention comes into play where a short portion of the gate outline is severed from the lid, at this score line, preferably at the end opposite to the hinge, as by an operation which may be called lancing. When a short portion of the score line is thus lanced, the gate will easily tear away from the lid at the remaining portion of the score line. However, the score line at this lanced portion must be securely sealed to prevent the contents of the can from leaking, even when the can is subject to internal pressure and/or is handled in a rough manner.

As will hereinafter appear, this scoring and lancing is contemplated with several types of gates, one of which is exemplified in the above mentioned patent, and the basic' feature of such types considered is that an edge of the gate will lap a portion of the can lid at the location where the can lid is lanced and sealing is required.

The invention is also concerned with a gated can lid where the gate is formed beneath an underfolded strip at the aperture of the opening and is pushed downwardly into the can to open it. The gate is necessarily immersed in the liquid contents of the can and accordingly, cleanliness-and sanitation are important. In the construction disclosed in the US. Pat. No. 3,334,775, the underfolded strip and the gate beneath it creates a shallow pocket which could be'a trap for substances which are contaminants. Regardless of the type of gate used, contaminants may adhere to the gate surface for the contaminants may be small solid particles or drops of various types of liquids which may accidentally fall onto the gate in the can lid.

The present invention was conceived and developed with the foregoing considerations in view and comprises, in essence, the use of a suitable inert sealer-filler which is applied to and about the gate in the can lid in such a manner as to fill any underfolded lap or channel between the gate and the lid. At the same time, the sealing substance must effectively fill and seal the lanced portion of the .score line defining the outline of the gate, and in some applications, even flow through the lanced opening and into a substantial portion of the score line and to surfaces adjacent to the score lineto protect the exposed metal surface at this score line and any adjacent metal surfaces where the coating of enamel, used with can lids of this type, is ruptured or abraded during forming of the gate.

It follows that an object of the invention is to provide, in a gated can lid having a gate which underlies, or partially underlies, an aperture in the lid and which is opened by being pushed downwardly, a novel and im-- proved arrangement of a sealer-filler in the can lid aperture, or channel, which eliminates the possibility of contaminant substances-being lodged therein.

Another object of the invention is to provide in a gated can lid having a partially lanced score line which extends about the periphery of the gate which is broken as the gate is pushed downwardly into the can, a novel and simplified arrangement of a filler and sealer to effect a leakproof fit of the gate at both the lanced portion of the score line and also at any other sections of the score line where it may have been ruptured as during the manufacture of the lid.

Another object of the invention is to provide in a gated can lid having a gate or a portion of a gate formed beneath an underfolded spacer strip about an aperture in the face of the can lid ,with the outline of the gate being defined by a score line beneath this underfolded spacer strip and with lanced openings at the score line to facilitate tearing the score line when the can.is being opened, a -novel and improved method of sealing this lid by using selected meltable or thermoplastic, or liquid thermo-setting types of natural or synthetic materials as a filler-sealer to close the lanced opening or any other break at the score line, which takes advantage of the, capillary action of a fluid sealant to seep into the lap between the spacer strip and gate, through the lanced opening, and thence into the score cut to effect a positive and complete seal, completely about the gate and which also will flow to form fillets to seal off and overlie, recessed portions of theaperture exposed to possible contaminents. I I

Another'object of the invention is to provide in a gated can lid of the type considered, asimplified mode of sealing and filling the gatedaperture, which is quick, reliable and economical. 1 3

With the foregoing and other objects in view, my present invention comprises certain constructions, combinations and arrangements-of parts andelements as hereinafter described, defined -in the appended claims, and illustrated in preferred embodiment by the accompanying drawing in which:. I p H FIG. 1 is a perspective view of the can having a pushin gate formed below a round aperture with an underfold of .the can lid.

. FIG. 2 is a plan view of the can illustrated at no. '1 to show the lid and gate therein with dotted lines indicating the outline of the gate panel beneath the aperture in the canlid.

FIG. 3 isa bottom view ofa portion of the can lid shown at FIG=2 illustrating the gate panel and a score line which separa es the gate from the edge of the panel underneath the aperture.

FIG. 3a is a fragmentary viewof a portion of the showing at FIG. 3 but on a greatly enlarged scale to show the lance in the score line.

FIG. 4 is a sectional view of a fragment of the can lid as taken from the indicated line4-4 at FIG. 2, but on a greatly enlarged scale with portions broken away to conserve space and with a sealer-filler material within the recess formed by the gate beneath the aperture to emphasize the manner in which this sealer-filler will flow into the crease beneath the spacer strip and the gate and through the lanced portion of the score line.

FIG. 5 is a fragmentary sectional view as taken from the indicated line 5-5 at FIG. 2 but on a greatly enlarged scale to show the manner in which the sealerfiller lies upon the gate and flows into the score line at the underside of the gate.

FIG. 6 is a fragmentary view similar to FIG. 3a but showing the manner in which the sealer-filler material can flow through the lanced portion and about 'the score line. i

FIG. 7 is a fragmentary detail similar to the showing at FIG. 5 but illustrating a modified embodiment wherein the gate is formed within an insert tab fitted into an opening in the can lid. I

FIG. 8 is a sectional view similar to FIG. 4, but showing a modified form of the gate panel with the center portion of the panel being raised and with the sealerfiller being indicated as flowing into the channel between the aperture and the raised portion of the gate and over an extended area at the underside of the gate and adjacent portions of the underfold and undersurface of the lid as may be obtained by fluxing the same.

FIG. 9 is a plan view of a portion of a lid similar to FIG. 2 but illustrating a modified embodiment wherein the gate is formed with an insert tab fitted into an opening in the can lid and with a channel formed in the lid about the edge of the tab to receive a sealer-filler.

FIG. 10 is a fragmentary, sectional view as taken from the indicated line 1010 at FIG. 9 but on a greatly enlarged scale with portions broken away to conserve space and with "a sealer-filler material within the channel between the gate and aperture and within the channel in the gate lid at the edge of the insert.

FIG. 11 is a plan view of a portion of a lid similar to FIG. 2, but illustrating a modified embodiment wherein the center of the gate is raised as in'the manner illustrated at FIG. 8 and wherein a score is cut at the upper surface of the gate as indicated in dotted lines.

FIG. 12 is a sectional view of a fragment of the lid as taken from the indicated line 12l2 at FIG.-11, but on a greatly enlarged scale, with portions broken away to conserve space, with a sealer-filler material within the recess formed by the gate beneath the aperture and with a small portion of the sealer-filler material at the lanced section of the score.

FIG. 13 is a plan view of a can lidsimilar to FIG. 2, but illustrating another embodiment of the invention wherein a gate is defined by a score line within a channel at the upper surface of the lid andwith broken lines indicating the location of an underlying tab at the lanced portion of the score line.

FIG. 14 is taken from the indicated line l4'14 of FIG. 13, but on a greatly enlarged scale with portions broken away to conserve space and with a sealer-filler material in the channel at the outer surface of the lid and at a portion of the undersurface of the lid where the lanced, lapped section occurs.

FIG. 15 is an isometric view of a portion of the underside of the lid, on an enlarged scale compared with FIG.

13, to show the bottom of the channel and the undersurface of the gate and the offset tab.

FIGS. 16 19, inclusive, are fragmentary sectional views as taken from the indicated line l919 at FIG. 15, but depicting the steps of a method which may be used to form the offset tab at the lanced portion of the gate.

FIG. 20 is a plan view of a can lid similar to FIG. 2 to illustrate yet another embodiment of the invention wherein the gate panel is horseshoe shaped and modified in structure.

FIG. 21 is a plan view similar to FIG. 20, but showing a pair of smaller gate panels which are U-shaped.

FIG. 22 is a bottom view of a portion of the can lid shown'at FIG. 20, but on an enlarged scale to illustrate the gate panel and a score line and lanced portion of the score line.

FIG. 23 is a fragmentary sectional view as taken from the indicated line 23--23 at FIG. 20, but on an enlarged scale and with portions broken away to conserve space.

FIGS. 24 and 25 are fragmentary sectional views as taken from the respective indicated lines 2424 and 25--25 at FIG. 20, but on an enlarged scale and with portions broken away to conserve space.

FIGS. 26 28 inclusive, are fragmentary sectional views depicting steps of a method which may be used to form the gate shown at FIGS. 20 25.

Referring first to the embodiment shown at FIGS. 1 6 of the drawing, a typical can C is formed with a lid L which is of a common construction except for a pushin gate G in the face of the lid. In the drawing this gate and the aperture are illustrated as being'circular; however, it is to be noted that the gate and aperture may be oval, U-shaped, triangular, rectangular tear-drop or in any other suitable form. The-gate G is integral with the can lid L and it is formed by underfolding and enlarging a portion of the lid to form a gate panel 20 beneath an opening or aperture 21 in the can lid. The underfolded gate panel 20 is separated from the lid L by a spacer strip 22 which extends beneath the can lid about the edge of the aperture-and above the edge of the panel 20. The outline of the gate panel 20 is defined by a score line 23 which is cut in the underside of the panel 20 in any suitable manner, and directly beneath the spacer strip 22. As best illustrated at FIG. 3, this score line 23 terminates at each side of ahinge portion 24, which is preferably near the center of the lid. It is contemplated that the gate may be pushed downwardly into the can by tearing it away from the lid at the score line 23, but the gate will remain attached to the lid at this hinge 24.

To facilitate breaking the; connection of the gate to the lid at the score line, a short portion of this score line is lanced or cut through, as at 25, preferably at the edge of the gate opposite the hinge 24. It is to be noted that the continuity between the gate panel 20 and the outer portion of the underfold below the spacer strip 22 connecting with the gate is not broken by this score line except at the lanced portion 15 which cuts completely through the sheet material forming the gate and the lid. The spacer strip 22 results from drawing and folding the lid material to produce a gate panel 20 which is larger than the aperture 21. This provides for a rounded, smooth surfaced aperture 21 at the fold where the spacer strip 22 joins with the lid L. This is advantageous since such a fold will not cut the fingers of a person pushing the gate into the can. At the same time, the underfold beneath the spacer strip 22, wherein the gate is located, is larger in diameter than the aperture 21 with its connection to the spacer strip being an outer edge fold 26 as bestillustrated at FIGS. 4 and 5. This produces a fold 27 between the top surface of the gate G and the undersurface spacer strip 22.

In the manufacture of a can lid, where the aperture structure, including the spacer strip, is drawn and folded, it is to be noted that this fold 27 cannot be completely closed with an airtight fit and accordingly, it is illustrated with a portion of the lapping surfacesbeing separated a short distance from each other. Actually the drawing is exaggerated somewhat for the lap or fold 27 is very narrow because the dies forming theaperture and the gate beneath it will exert considerable pressure. against the lid, spacer strip and gate. However, no matter how tightly the spacer strip bears against the gate panel, liquids which adhere to the surface of the material forming this lid and panelcan seep between the two members by capillary action. Such liquids may be contaminating fluids such as dirty water or the like and if a drop of such a liquid were to fall into the gate aperture, it would seep into this space and thence into the can when the gate is opened. Also, small particles, such as dust, filings or the like can be lodged in the aperture against the edge of the spacer strip 22. Therefore-it is important to provide a means to prevent such from occurring, because the gate must be clean and'sanitary.

The present invention contemplates placing a liquid sealer-filler 30 in the aperture 21, above the gate, which will flow into the fold 27 between the spacer strip 22 and the edge of the gate panel G and also flow onto the lanced opening 25 to form a plug 31 to seal off this opening, as hereinafter further described. This sealer-filler must then set andharden to produce a smooth surfaced fillet 32 about the edge of the aperture which encloses the fold of metal at this edge 21. The fillet will prevent contaminant liquids from seeping into the lap and also prevent small solids from lodging against this aperture edge. If desired, a sufficient amount of sealer-filler material may be provided to completely fill this aperture.

An ideal material for the sealer-filler may be selected from a number of different types of paraffin waxes which are comonly available. One suitable type is micro-crystalline paraffin wax. Paraffin waxes are petroleum products and may be refined to the point where substantially all oils have been removed and the comparatively pure wax is white, odorless, tasteless and practically impervious to moisture. As such, paraffin waxes are widely used in the food and beverage industries for lining containers. These waxes will melt at-various ranges of temperatures, to a liquid of low viscosity which has good adhesion and adsorption to metal surfaces. Paraffin and other types of synthetic or natural waxes are commonly blended together to attain a selected degree of hardness and resistance to cold flow when they cool and set. A technician skilled in-the'art can select various waxes and wax blends, suitable: for

the purpose at hand.

Other materials, such as natural and synthetic resins,

are also suitable for the filler-sealer. For example, a

number of polymeric sealants are known, such as a thermosetting polyepoxide or a thermoplastic ethylene vinyl acetate copolymer. Such materials must be meltable to a liquid or be liquid in an initial state. The liquid must have a low viscosity and an affinity for the'metal or coated metal forming the lid and gate to produce the needed capillary action to form the fillet 32 to permit it to flow into the closely spaced fold 27 between the spacer strip 22 and gate surface and thence into the lance opening 25. This material must then harden and set to a stiffness sufficient to resist the pressures within the can to prevent a flowback ior leakage at the opening 25. Finally, the material must be acc'eptablefor use in dersurface of the can lid.

connection with beveragesand foods. A skilled technician can easilyselect suitable resins for the purpose at hand knowing the conditions above stated.

The metals commonly used in the manufacture of can lids include aluminum and steel. Thus, paraffin waxes arepreferred for a sealer-filler material since they have good affinity for, and good adhesion with these metals and conventional can lining materials, usually lacquers or enamels. v

When the sealer-filler consists of a wax-like material which must be melted, its application includes the steps of heating the can lid to a selected temperature to permit the wax to melt and flow in place. This heating of the can lid may be one of the final steps in the manufacture of the lid and it can be accomplished in any suitable method such as passing the lid through an oven, with, infra-red radiation, placing the lid upon a heat source plate, flame heating or heating by electrical induction methods. It is important that the lids be heated quickly since they are ordinarily produced at a great rate and'a skilled operator can select the best mode of heating the lids for any given production operation. The wax may be pre-meltedora small pellet of wax may be placed on theheated lid, in the aperture, to melt and flow to the edges of the aperture and underneath the lap 27 by capillary action. Thereafter, the lids will be cooled to permit the wax to setto complete the operation. Y

When a microcrystalline wax was used to seal can lids, as above described it was discovered that the flow of waxwas remarkably uniform and that wax which would flow into the fold 27 by capillary action would easily andrapidly flow through the lance 25 and into the score line 23 about the edge of the gate as a bead 33 which overlays the exposed metal in the score line. It was further ascertained thatvif a fluxing agent were used, the wax would not only follow the score line where exposed metal. existed, but also would spread about the undersurface of the gate and lid where the fluxing agent was applied.

Such a flux may be applied during the operations of drawing and shaping the can lid to form the aperture 21, the spacer strip and the gate beneath the lid because it is necessary to use a lubricant on the dies which form the. gate beneath the lid and such lubricant may be the fluxing agents. A naptha-wax blend is a commonly used type of lubricant and is a good fluxing agent which will permit the paraffin to flow over a selected area at each-side of the score line,as hereinafter further described. Such a fluxing agent, a naptha-wax blend, can also be printed onto a selected portion of the un- Where a thermosetting type of a synthetic resin plastic is used:.to effect a seal, such as with a two component thermosetting resin such as a polyepoxide which is initially in. a liquid phase but which will thereafter set up, the same simple procedure may be used. A drop of the liquid resin is placed in the aperture to flow into the A uid resin will be permitted to set into a hard resistant material, either bygheat action or through reactions "over a lapse of time, according to conventional practice. It is to be noted that when a material other than a paraffin wax is used, the flow of material from the gate and into the raw metal score line may not be very effective and hence, a respray operation which applies a thin coating of paraffin, or other coating conventional in can making practices, to the underside of the lid may be necessary.

An important factor in the present invention resides in the location of the lanced opening 25 which is at only a very small portion of the gate periphery. The lanced opening lies against the lapped fold 27, the spacer strip 22 forming a backing surface at the fold. Thus, the plug 31 in the lanced opening is reinforced by the lap 27 to withstand pressure within the can. Should the opening 25 be located in a portion of the lid where another closely lapped backing surface does not exist, the plug 31, formed by the wax seal, cannot resist the shear forces produced by any substantial pressure within the can; after a short period of time, such a plug-like seal would give way. However, with the closely lapped backing surface, exemplified at FIGS. 4 and 10, the wax plug 31 must first flow between two closely spaced surfaces, the spacer strip 22 and the gate panel G, before giving way. Moreover, pressure within the can will tend to squeeze these surfaces together. Thus, the plug 25 can resist substantial pressures within the can.

Various modified arrangements of a gate in a can lid may use the present invention. FIG. 7 illustrates a construction where a conventional insert 35 is provided within an opening 36 in the can lid and this insert 35 is modified by providing a score line 23x underneath the gate panel the same as heretofore described. In such an arrangement, the insert panel is first formed as a conventional cup-shaped member, not shown, having a flange 37. This member is inserted into the opening 36 in the can lid L, with the flange 37 at the top surface. Thereafter, the offset panel G is formed underneath a spacer strip 22x. The spacer strip 22x will lie against the undersurface of the lid about the lid opening 36 and the spacer strip will connect with the gate panel G wherein a score line 23x is cut as heretofore described.

In the construction of a conventional insert, a synthetic resin plastic seal 38 is provided at the underside of the can lid and about the edge of the insert to secure the insert in place with a leakproof fit. However, to complete the unit, a sealer-filler 30 is then placed in the aperture formed in this insert, and a fillet 32 will form in this aperture the same as heretofore described. Also, wax will flow through the lap 27x and thence through the lanced portion, not shown, and about the score line 23x underneath the gate as a bead 33x.

FIG. 8 illustrates another arrangement of a gate G in a lid L which is similar to the construction shown at FIG. 4 excepting the gate G is raised by an upsloping wall 40 at the aperture to provide a central dome 41 which may lie in the plane of the lid, or even above that plane, to facilitate pushing the gate panel against the score line to open it. A wax sealer-filler is applied to the aperture 21 in the channel about the gate between the aperture 21 and the upsloping wall 40, as heretofore described. The sealer-filler 30 will flow into the lap 27 and through a lance opening 25, as heretofore described. Thence, the wax will fiow about the score line 23 where metal is exposed. v

This FIG. 8 also shows the manner in which the wax sealer-filler may be spread over the undersurface at any selected area of the lid and gate whenever a suitable fluxing agent is applied to the area. The area, illustrated at FIG. 8, is exemplary of a desirable portion to be covered by the wax layer 42, that is, at the edge of the gate panel G where the folded spacer strip is located and at a portion of the lid adjacent to this panel edge where a fillet 43 forms between the underfold and underside of the can lid. The wax applied to the lid at the top of the aperture will thus flow through the lanced opening and thence about the score line and over the selected area as at 42, which may be the entire gate panel. Also, if sufficient wax is used, a wax covering may cover the top of the gate panel.

FIGS. 9 and 10 show a construction of a gate G formed within an insert such as shown at FIG. 7. The gate G shown in this insert 35, FIG. 10, differs from the gate G shown at FIG. 7, in that a raised central dome 41 is provided in the face of the gate. A further modification occurs by providing a channel 45 in the lid L at the peripheral edge of the insert with the edge of the top insert flange 37 reaching and turning into this channel 45, as illustrated. With this arrangement, whenever a wax sealerfiller is applied to the gate, a small amount of additional wax can be applied in this channel as at 46 to seal the lapping edge of the insert, as illustrated. This procedure will.permit the sealant to flow between the flange 37 and can lid to seal the insert and eliminate the comparatively expensive plastic seal 38 shown at FIG. 7.

The modified constructions at FIGS. 11 and 12 depict a can lid having a gate G which is substantially the same as the gate illustrated at FIG. 8. However, the score line 23a is at the upper surface of the gate in the fold 27 between the gate surface and the spacer strip 22, such being best illustrated at FIG. 12. In this unit, the filler-sealer will form a fillet in the channel between the inclined wall 40 of the gate G and the edge of the aperture 21. It is to be noted that no metal surfaces will be exposed at the underside of the lid except at the lance 25, and accordingly, when the sealer-filler is applied to this structure, a plug 31 will form in the lance opening 25 and need not spread further.

The construction shown at FIGS. 13 15 illustrates a gate G which is formed in the face of a lid L" without providing for a spacer strip below an aperture. The outline of the gate G is defined by a'score line 23" at the upper surface of the lid L. This score line 23" is at the bottom of a channel 50 which assumes the same form as the gate. For example, the gate is illustrated in the drawing as being circular and accordingly, the channel is also circular. This score line 23" is interrupted by a hinge portion 24" at the side of the gate adjacent to the center of the can, as heretofore described, and a lance opening 25" is located diametrically opposite to this hinge. Accordingly, the gate may be opened by pushing it downwardly at the edge adjacent to the lanced opening to tear the metal at the score line as the gate moves into the can away from the lid.

A wax sealer-filler 30 may be used to fill this channel 50, as best illustrated at FIG. 14, and the sealerfiller will also seal off the lanced opening 25". To prevent the pressure of the contents within a can from blowing out the wax sealer-filler at the lanced opening, an edge portion of this gate at the lanced opening underlies the adjacent aperture portion of the can lid as a small tab 51, as illustrated in broken lines at FIG. 13 and also at FIGS. 14 and 15. This tab is formed by stretching the metal of the gate adjacent to the lanced portion so that it may provide for a lap 27". Although the material forming the tab 51' will be formed under considerable pressure, the resulting lap 27"'will not fit against the underside of the channel 50 in a perfect manner and when a wax sealer-filler is applied to the channel 50, it will flow through this lap portion by simple capillary action to set up as a fillet 52 at the underside of the gate, as best illustrated at FIG. 14. The tendency for leaks to occur will thus be minimized since the thin layer of wax between the overlapping portions of the gate and can lid, at the channel, will prevent a leak flow from this opening 25. The underlapping of the tab 51 forms a backing surface for this thin layer of sealant and also constitutes a reinforcement to resist pressure.

The steps for forming this tab 51 and the lap 27" are illustrated at FIGS. 16 through 19. The first step of operation is to draw the channel 50 which has an arcuate cross section as shown at FIG. 16. The second step, shown at FIG. 17, is to select and to form an enlargement 53 of the metal at the location of the projected tab, adjacent to the point where the gate will be lanced. Next, the score line 23 may be cut to form the outline of the gate. Next, a short portion of the score line, at the enlargement 53, is lanced, as shown at FIG. 18. Finally, this lanced portion is compressed, or bumped in any suitable manner, not shown, to form the overlap of the tab. This stretched metal forming the tab underlies the lid at the lanced portion, as illustrated at FIG. 19, and the final step of operation will be to fill the channel with sealant as heretofore mentioned.

The construction shown at FIGS. and 22-15, discloses a can lid L with a gate H having an offset panel 60 underneath a horseshoe shaped aperture. The horseshoe form of the aperture includes opposing sides 61 which converge tangentially from a circular end portion 62. The construction shown at FIG. 21 discloses a can lid L having a pair of smaller gates H, at opposite sides of the can, each of which is, for all purposes, identical to the gate H shown at FIG. 20, excepting that the opposing sides 61' of each gate extend in spaced parallelism from a circular end portion 62'. The horseshoe shapes shown are merely exemplary of other shapes, such as a triangle, a truncated teardrop, a rectangle or the like.

As best shown at FIGS. 23 and 24, the gate structure about the horseshoe shaped

aperture edge

61 and 62 is substantially identical to that heretofore described with an underfolded spacer strip 22h about the

edges

61 and 62 of this aperture with the gate panel 60 lying beneath this spacer strip 2211 and connecting therewith by an outer edge fold 26/1. A score line 2311 at the underside of the panel is also substantially the same as heretofore described, extending about that portion of the panel underneath the spacer strip 22h. This score line is lanced as at 2511, adjacent to the center of the circular end of the aperture 62.

The folded portions to define the spacer strip 22h terminate at the extended ends of the straight sections of the aperture, and the reach between these extended ends is a sloping offset will 64 between the surface of the lid L and the panel 60. The hinge 2411 is located at the bottom of this wall 64 as best indicated at FIG. 23.

It follows that the underfolded spacer strip 22h, terminating at the extended ends of the straight sections, will taper from a maximum width as shown at FIG. 24, to

a vestige 65 as shown at FIG. 25, and then fair into the offset =-wall portion 64. V 3 V A sealer-filler 30 will be applied to the gate panel 60, the same. as heretofore described, to produce a plug 31 at the lanced portion 25h and a fillet 32 at the aperture edge 61-62. It will also produce a modified fillet 32h at the hinge. 2411. This sealer-filler, of suitable microcrystalline wax or like material, will flow into the lap 2711 between the spacer strip 2211 and the panel 60, thence through the lanced opening 25h and thence about the score line 2311 as a filler 3311, the same as heretofore described.

FIGS. 26 28 indicate diagrammatically certain steps which may be used in a method for forming the gate H shown at FIG. 20. FIG. 26 indicates one of the first steps by forming a rounded indentation 66 in the can lid L to stretch the metal where the gate is to be located. FIG. 27 illustrates a subsequent step of forming the panel 60, the offset wall 64 and a wall section 67 between the panel 60 and the gate lid L which will subsequently form the spacer strip 2211. FIG. 28 shows a subsequent step where the wall section 67 is flattened to produce the spacer strip 2211 between the gate panel 60 and the lid L.

I have now described my invention in considerable detail. However, it is obvious that others skilled in the art can build and devise alternate and equivalent constructions which are nevertheless within the spirit and scope of my invention. Hence, I desire that my protection be limited not by the constructions illustrated and described, but only by the proper scope of the appended claims.

I claim:

1. In a can lid having a pushdown gate defined by a score line in the face of the lid, which is torn and severed when the gate is pushed downwardly into the can, and a small, narrow, lanced opening at the score line to facilitate the initiation of the tearing and severing of the score line whenever the gate is pushed downwardly, a sealing arrangement including:

a portion of the can lid folded against and lapping over the gate at the lanced opening to constitute a back-up surface at the lanced opening;

an offset in the outer surface of the can adjacent to the lanced opening forming an indentation; and

a wax-like sealer-filler, of a type which may be obtained as a settable fluid, extending continuously from the indentation as a fillet, thence between the back-up surfaces as a capillary layer and thence into the lanced opening as a plug.

2. In the organization defined in claim 1 wherein:

the sealer-filler is a blend of paraffin waxes.

3. In the organization defined in claim 1 wherein:

the sealer-filler is a polymeric sealant having the general characteristics of a thermo-setting poly epoxy which may be applied to the lid in a liquid state to facilitate the flowing of the same into the lanced opening and between the lapping surfaces through capillary action.

4. In the organization defined in claim 1 wherein:

the sealer-filler is a polymeric sealant having the general characteristics of a thermo-plastic ethylene vinyl acetate copolymer which may be heated to a liquid state and applied to the can lid to permit the same to flow between the lapped surfaces and thence into the lanced opening by capillary action.

5. In the organization defined in claim 1 wherein:

at the score line and said sealer-filler extends into the channel as a fillet to prevent foreign substances from collecting in the channel. 7. 1n the organization defined in claim 1 wherein: the score line is at the underside of the bid and said sealer-filler plug extends through the lanced opening and into the score line.

Claims

1. In a can lid having a pushdown gate defined by a score line in the face of the lid, which is torn and severed when the gate is pushed downwardly into the can, and a small, narrow, lanced opening at the score line to facilitate the initiation of the tearing and severing of the score line whenever the gate is pushed downwardly, a sealing arrangement including: a portion of the can lid folded against and lapping over the gate at the lanced opening to constitute a back-up surface at the lanced opening; an offset in the outer surface of the can adjacent to The lanced opening forming an indentation; and a wax-like sealer-filler, of a type which may be obtained as a settable fluid, extending continuously from the indentation as a fillet, thence between the back-up surfaces as a capillary layer and thence into the lanced opening as a plug.

2. In the organization defined in claim 1 wherein: the sealer-filler is a blend of paraffin waxes.

3. In the organization defined in claim 1 wherein: the sealer-filler is a polymeric sealant having the general characteristics of a thermo-setting poly epoxy which may be applied to the lid in a liquid state to facilitate the flowing of the same into the lanced opening and between the lapping surfaces through capillary action.

4. In the organization defined in claim 1 wherein: the sealer-filler is a polymeric sealant having the general characteristics of a thermo-plastic ethylene vinyl acetate copolymer which may be heated to a liquid state and applied to the can lid to permit the same to flow between the lapped surfaces and thence into the lanced opening by capillary action.

5. In the organization defined in claim 1 wherein: the gate is at an underfold below an aperture in the can lid with the edge of the underfold defining the aforesaid indentation, and wherein the sealer-filler extends completely about this underfolded edge as a fillet to prevent foreign substances from collecting in the aperture.

6. In the organization defined in claim 1 wherein: the indentation comprises a channel about the gate at the score line and said sealer-filler extends into the channel as a fillet to prevent foreign substances from collecting in the channel.

7. In the organization defined in claim 1 wherein: the score line is at the underside of the bid and said sealer-filler plug extends through the lanced opening and into the score line.