US3616114A

US3616114A - Reusable composite adhesive sealing tapes

Info

Publication number: US3616114A
Authority: US
Inventors: Tsuneji Hamaguchi; Hajimu Tanaka
Original assignee: Sekisui Chemical Co Ltd
Current assignee: Sekisui Chemical Co Ltd; Procter and Gamble Co
Priority date: 1967-03-15
Filing date: 1968-03-15
Publication date: 1971-10-26
Anticipated expiration: 1988-10-26
Also published as: DE1611923A1

Abstract

Reusable, composite, adhesive sealing tapes for releasably interconnecting container parts and the like, such as corrugated boxes, paper bags, etc. The tapes, cut to a suitable length and width, include at least two tape portions or laminations, namely a main tape portion and a partly coplanar reinforcing tape portion; optionally, an auxiliary tape portion may also be provided. The inner end of the reinforcing portion is firmly attached to the midportion of the main portion. The latter has a first area adapted to be attached to one side of a first container part, while a second area thereof, including its free end, is adapted to be attached to a second container part which should be releasably interconnected with said first container part; the reinforcing portion is at least partly attachable to the opposite side of the first container part. A turned-up section formed from the inner end of the reinforcing portion may constitute a hinge for said first area of the main portion when it is attached to the respective container part.

Description

United States Patent [72 Inventors Tsuneji Hamaguchi Osaka; llllajimu Tanaka, Suita, both of Japan [21] Appl. No. 713,347 [22] Filed Mar. 15,1968 [45] Patented Oct. 26, 1971 [54] REUSABLE COMPOSITE ADHESIVE SEALING TAPES 11 Claims, 4 Drawing Figs.

[52] US. Cl 161/39, 117/122,117/685,161/102,161/l45, 161/406,

[51] Int. Cl B32b 3/04 [50] Field of Search... 229/49, 45, 51 ST; 161/38-39, 145, 149,406, 102,99-100,

167; 117/68.5,122 P, 122 PA; 206/59 C [56] References Cited UNITED STATES PATENTS 3,329,331 7/1967 Morgan 161/406 X Primary Examiner- Philip Dier Attorney-Tab T. Thein ABSTRACT: Reusable, composite, adhesive sealing tapes for releasably interconnecting container parts and the like, such as corrugatedboxes, paper bags, etc. The tapes, cut to a suitable length and width, include at least two tape portions or laminations, namely a main tape portion and a partly coplanar reinforcing tape portion; optionally, an auxiliary tape portion may also be provided.

The inner end of the reinforcing portion is firmly attached to the midportion of the main portion. The latter has a first area adapted to be attached to one side of a first container part, while a second area thereof, including its free end, is adapted to be attached to a second container part which should be releasably interconnected with said first container part; the reinforcing portion is at least partly attachable to the opposite side of the first container part. A turned-up section formed from the inner end of the reinforcing portion may constitute a hinge for said first area of the main portion when it is attached to the respective container part.

Pmmmum 26 Ian 3,616.1 14

' SHEET 1 BF 2 INVENTORS TSUNEJ'I HAMAGUCHI BY ijAJlMiTANAKA AGENT PATENIEDum 2s ISYI 3,616,114

SHEET 2 OF 2 INVENTORS TSUNEJI HAMAGUCHI BY HAJIMU \TANAKA AGENT REUSABLE COMPOSITE ADHESIVE SEALING TAPES The invention relates to reusable composite sealing tapes (which can also be tenned sets of tapes) used for sealing, for example, the mouth of a box, a bag or other container, made of cardboard, paper or some other suitable material.

The inventive sealing tapes are especially useful for releasably interconnecting cover flaps of boxes or the like, made of relatively thick cardboard, such as corrugated board, having a relatively high stacking or compressive strength.

The inventive sealing tapes have superior characteristics such as low price, easy manufacture and handling when fitting the same to the mouth of a box or a bag, and the facility of repeated use without any fear of injuring or harming the box or the bag to which it was attached. The use of adhesive tapes for sealing the mouth of a box or a bag is well known. The conventional methods, however, are relatively primitive, such as when a single strip of adhesive tape, cut to the required length, is directly attached to the mouth, e.g. by means of an adhesive. The tape may tear the surface of the box where it is glued on, particularly when the tape is peeled away or removed for unpacking. Another major disadvantage resides in that a tape, once it has been used, cannot be used any more for resealing; quite frequently the box or bag itself cannot be reused either. Consequently the use of conventional adhesive tapes is restricted to cases where a box or a bag, and also the tape proper, might not be expected to be reused.

The sealing by means of adhesive tapes is, however, capable to be put to better use for simpler and faster scaling, in comparison with other sealing means. Those skilled in the art have therefore sought for a long time the development of a new reusable adhesive sealing tape.

One of the major objects of this invention is to provide a reusable adhesive sealing tape which avoids the above-mentioned drawbacks and fulfills the explained demands.

Another object is to provide composite sealing tapes which are easy to manufacture, store and apply, over and over again, for boxes and the like containers.

It is yet another object to provide sealing tapes of the kind described which consist of a minimum number of portions, for example, only two tape portions which together constitute the composite tape or set of tapes.

This invention relates to composite sealing tapes including a main and a reinforcing tape portion, one end of the latter being firmly attached to the midportion of the undersurface of the former; moreover, the former is placed above the latter in such a way as said undersurface is in coplanar contact with the top surface of the latter.

In the inventive sealing tapes, materials such as cloth, kraft paper, cellophane paper, plastic sheets, plastic laminates, etc. can be used for the tape portions as well as for backing, if provided, the undersurface thereof being entirely or partly coated with a conventional pressure-sensitive adhesive. The surfaces of the tape portions may also be treated with conventional releasing agents to an extent which will permit sufficient adhesion to the adhesive-coated undersurfaces of the adjoining respective tape portions, when compressed, but do not cause any dislocation of the adhesive layers or films on the undersurfaces when one tape portion is separated or peeled off from another.

Moreover, some conventional primer coating may be applied between the tape portions and adhesive layers in order to obtain a stronger adhesion, as is well known in this particular field of invention.

Any conventional pressure-sensitive adhesive and/or compatible releasing agent may be used for the sealing tapes of the present invention, such as have been disclosed in various earlier publications, for example: U.S. Pats. 2,236,567 of Apr. 1, l94l to Richard G. Drew, titled Adhesive Sheeting"; 2,319.959 of May 25, 1943 to Hubert J. Tierney, Adhesive"; 2,532,0l l of Nov. 28, 1950 to Carl A. Dahlquist et al., Liners and Adhesive Tapes...; 2,697,084 of Dec. 14, 1954 to Laszlo W. Eger, Adhesives..."; 2,822,290 of Feb. 4, l958 to Charles S. Webber, Release Coatings..."; 2,880,862 of Apr. 7, I959 to John T. Sermattel, Chemical Process and Product; and primarily U.S. Pats. 2,971,863 of Feb. 14, [961 to Harold V. Kindseth et al., Pressure Sensitive Tape and 2,987,420 of June 6, 1961 to Cyrus W. Bemmels et al., Pres sure Sensitive Adhesive Composition...," as well as German Pat. No. 855,746 of Nov. l7, I952 to Kurt Fendius (Assignee P. Beierdorf & Co. A. 0., Hamburg), relative to an adhesive sealing tape.

Optionally, the invention contemplates a set of three rather than two tape portions, including a main tape portion, one half of which holds and clamps adhesively the: cover flap or other part of the mouth of a box or a bag, in cooperation with a reinforcing tape portion, as explained before, the opposite half thereof extending to the other cover flap of the box or bag mouth, and having a free adhesive undersurface which may be stuck or otherwise attached to the other cover flap. This embodiment includes an auxiliary adhesive tape portion which is attached with adhesive to the surface of said other cover flap at the location where the free adhesive undersurface of the main tape portion will abut.

The auxiliary tape portion can, however, be omitted when the other or opposite cover flap, which :may match with the free adhesive undersurface of the main tape portion, has previously been treated with releasing agents or covered with cellophane paper, vinyl tape or some other suitable material in lieu of the aforementioned auxiliary tape portion.

For all practical purposes, the present invention can be embodied as a set of only two tape portions or laminated strips, as explained before, including the main and the reinforcing tape portions, to full satisfaction for repeated use, without detriment to either tape or container (box, bag or the like).

It is to be understood that in practicing the invention there can be used various widths, lengths and materials for the tape portions, to be selected in accordance with the material, the size and other characteristics of the box, bag or the like container for which the sealing tape should be used.

According to further features of the inventive sealing tapes, a mark may be applied to the top surface of the main tape portion, for identifying an area which is to be located edgewise on the first-mentioned cover flap of the box or bag when the sealing tape is applied thereto.

For storage and transportation, the inventive sealing tapes may be provided with a suitable backing material for covering the respective exposed undersurfaces of the tape portions. Optionally, a picking tab may be provided at the free end of the main tape portion, constituted either by a turned-in terminal portion of said tape portion or by a separate piece of material 1 secured to the undersurface of the main-tape free end.

Other objects and many of the attendant advantages of the invention will be readily appreciated as the same becomes better understood by reference to the following detailed description, when considered with the accompanying drawings, wherein FIG. I is a somewhat schematic, perspective illustration of a first, exemplary embodiment of a reusable composite sealing tape according to the present invention, including only two tape portions;

FIG. 2 is a similar illustration of a second embodiment according to the invention wherein the sealing tape has three tape portions;

FIG. 3 shows a third embodiment of the inventive sealing tape;

FIG. 4 illustrates a fourth embodiment; and

FIGS. 4A to 4D illustrate consecutive procedural steps, in vertical sectional views, for applying the fourth exemplary sealing-tape embodiment asshown in FIG. 4 to coverflaps of a container.

FIG. I shows the simplest embodiment of the inventive reusable composite sealing tape, including a top or main t p portion generally designated 1 and including terminal areas Ia and lb, the latter being termed the free end of the tape portion 1, as well as a bottom or reinforcing tape portion 2. The inner end of the tape portion 2 is turned up as shown at 2a so that the undersurfaces of the two tape portions I and 2 touch each other. These undersurfaces are preferably given a coat or layer of a conventional pressure-sensitive adhesive as indicated by the stippling on the surfaces marked with numeral 4. Examples of suitable materials were described in the patents enumerated earlier in the specification. A mark of line the undersurfaces of both tape portions 1 and 2 before the l 5 sealing tape is put to use.

The turned-up section is preferably inseparably or at least firmly attached to the undersurface of portion 1, also to be explained later in full. It will be understood that the tape portions 1, 2 can be made longer or shorter; the free end of 20 portion 2 should preferably project beyond the free end of portion lb or its picking tab 6, if provided. The width of the tape portions can be adapted to the particular sealing job to be accomplished; evidently a wider sealing tape will have a stronger adhesion to the cover flaps of the container parts to which it is temporarily or permanently attached.

FIG. 2 shows a second embodiment of the sealing tape wherein an auxiliary tape portion 3 is disposed below the reinforcing tape portion 2. Preferably the inner end of portion 3 is shorter so as not to interfere with the turned-up section 2a of the tape portion above. In other respects this embodiment is much like the previously described simplest embodiment.

FIG. 3 shows another sealing-tape embodiment with three laminations or tape portions wherein the inner end of the auxilia ta e ortion 3 is inserted in the s ace 2a formed W P P P between the parallel areas of the turned-up section 2a. The sequence of the (-portions in this modified embodiment is 7 1-3-2 (-8) when going from top to bottom whereas, it will be understood, the preceding FIG. 2 displayed a sequence of l-23 (8). FIG. 3 shows an alternative picking-tab solution in that the free end lb is turned back so as to form a tab 1,; which performs substantially as the tab 6 shown in the other figures. it is to be understood of course that these expedients are interchangeable, and either can be used in any of the illustrated exemplary sealing-tape embodiments. 4

FIG. 4 illustrates a modification wherein the inner end of tape portion 3 is spaced apart from the turned-up section 20 so as to provide a small gap, substantially below the mark or line 1d, again as will be explained later in more detail. Preferably the free end of the reinforcing tape portion 2 projects beyond the free end of the auxiliary tape portion 3, as shown in FIGS. 3 and 4.

In all four illustrated exemplary embodiments, the undersurfaces of the

tape portions

1, 2 and 3 are coated with the pressure-sensitive adhesive as the respective layers 4. Preferably, the reusable composite sealing tapes according to the invention are so constructed as to prevent mutual sticking of the adhesive layers of the respective tape portions when in use for sealing the mouth of a box or a bag except that the turned-up section 2a is firmly attached, as mentioned before, to the undersurface of the portion 1. This makes for almost perfect fixing and integration of the components in the composite sealing tape.

The inner end of the portion 2, with its turned-up section surface of a box or bag, while area lb is releasably attachable to a cover flap or other part of the box or bag, as will be explained with reference to FIGS. 4A through 4D.

It is the purpose of the auxiliary tape portion 3 to provide a protection against tearing off the surface of the box or bag due to the adhering force of the main tape portion 1 in cases when the mouth is opened by peeling off the free portion lb of the main portion 1. It should be noted in this connection that the length of the free or terminal area or portion lb has an effective adhesion length in order to fulfill its purpose. It will be understood that the free end of the reinforcing tape portion 2 is made to project beyond that of the auxiliary tape portion 3, as shown in FIGS. 3 and 4.

Each of the

tape portions

1, 2 and 3 is made of a material or backing such as cloth, kraft paper, cellophane, plastic sheets, or other suitable materials, or laminates thereof, to which the adhesive layers 4 are applied. For the reinforcing tape portion 2, kraft paper is more effective because it is not easily deformed, and also from the standpoint that the portion 2 has to keep the attached area la of the main tape portion 1 in good adhesive contact with the cover flap of the box, by the aid of the section 2a when the main portion 1 is peeled off or separated with its terminal portion lb.

Any of the

tape portions

1, 2 and 3 may have its top surface, opposite the undersurface which has the adhesive layer 4 thereon, treated with a suitable releasing agent. This treatment has to be done in such a way that the top surface maintains satisfactory adhesion with the adjoining adhesive layer when the same is pushed against it but is releasable therefrom without dislocating the same, if necessary.

In the exemplary embodiments shown in FIGS. 3 and 4, if the force necessary for peeling off the main tape portion 1 from the auxiliary tape portion 3 is determined to be greater than that necessary for peeling off the auxiliary portion from the reinforcing tape portion 2, this is very favorable because the main and the auxiliary portions can be peeled off together from the reinforcing portion after the composite tape has been attached to one of the cover flaps of the box or bag.

It has been mentioned before that a backing tape or material 8 may be temporarily attached for protecting the adhesive layers 4. It should be understood that when the composite tapes according to the invention are stored or supplied for ultimate use, in the form a bundle or a set, including a plurality of superimposed composite tapes, it will be sufficient that only the lowermost tape portion of the very lowest composite tape be provided with the backing material. The individual sealingtape units can easily be taken apart without sheets of backing material inserted therebetween, particularly if the aforedescribed releasing agent is applied to the top surfaces of 5 the tape portions, especially to that of the main tape portion.

In the following, consecutive procedural steps will be described with reference to FIGS. 4A, 4B, 4C and 4D, showing how centerline fourth sealing-tape embodiment of FIG. 4 is applied to cover flaps of a container, schematically shown herein with sectioned cover-flap portions A and B, respectively, which have to be temporarily and releasably interconnected.

First of all, if there was a backing material 8 attached to the bottom of the composite sealing tape of FIG. 4, this is removed. Then the adhesive layer 4 of the first terminal area la of tape portion 1 and the inner end portion 2a of the tape portion 2 are attached to the top surface of the cover flap A, as shown in the right-hand side of FIG. 4A, in such a way that line ld printed on the top surface of portion 1 substantially coincides with the edge of the cover flap A, as shown.

Then the rest of the sealing tape is folded about the edge toward the undersurface of the flap A and the rest of the portion 2 is stuck to said undersurface with some force.

Although the sealing tape of FIG. 4 has been described so far it may be noted at this point that when using the tape of FIG. 3, the innermost end of the auxiliary tape portion 3, which is originally inserted between the limbs of the turned-up section 2a of the tape portion 2, would not become attached to the undersurface of the flap A.

In the next step, the tape portion 3, in combination with the free or terminal section lb, is peeled off and pulled upwards, as viewed in the drawing, beyond the edge of the flap A, and then the auxiliary tape portion 3 thus lified up can be stuck onto the opposite cover flap B of the box (see subsequent FIGS. 48 and 4C, respectively).

ln the stage shown in H6. 4C, portion llb is attached, on one hand, to the top surface of the portion 3 (adhering to the flap B) while, on the other hand portion llb is also attached to the undersurface of the portion 2 at its turned-up section 2a (which in turn adheres to flap A). Thus the sealing between the flaps A, B is accomplished.

For purposes of releasing the seal or connection between the flaps, the portion llb can be peeled off or separated, as shown in H0. dlC, by pulling upwards the picking tab 6 (or its modified version llc, as shown in FIG. 3). Moreover, in cases when it is required to leave the mouth of the box or container unsealed for some period, the free portion llb may be temporarily attached to the outer surface of the reinforcing tape portion 2 on the inner side of the cover flap A. This will also allow the adhesive layer ll applied to the undersurface of the free portion llb to maintain its adhesive ability since the layer is protected from air. Any subsequent sealing and unsealing can be perfonned merely by repeating the above-explained procedure with reference to the free portion lb of the main tape portion ll. This of course is shown in MG. lll) where portion lb has been lifted off the cover flap B.

It should of course be understood that the procedural steps described with reference to H618. 4A to All) do not apply to the fourth embodiment of FIG. ll alone. ln particular, the first exemplary sealing-tape embodiment of HG. ll can be used to the same effect in that the only difference will be no intermediate layer (the auxiliary tape portion 3) between the portion lb and the cover flap B. As has been explained before, the container itself may be given an appropriate surface, at least in the area of the flap B, for example if the same is treated with a releasing agent, or covered with cellophane paper, vinyl tape or the like.

When the tape of FIG. 3 is used in the manner shown in the procedural illustrations, the inner end which originally projects into the section 2a, can be folded down about the edge of the cover flap B, as shown by the dot-dash line constituting an extension thereof in FIG. 4ND. This will threefold effect for the edge of flap B, in a manner similar to that provided by the reinforcing tape portion 2 which is folded about the opposite edge of the flap A.

For many years, the repeated sealing with adhesive tapes has been considered to be impossible. The present invention, however, makes this sort of sealing not only possible but economically desirable. in this respect, the invention is believed to be novel and very useful.

in a composite sealing tape of the kind herein described and illustrated, the main tape portion is of course subjected to the strongest pulling force. As has been explained in the foregoing, this portion is substantially integrally connected to the end portion 2a of the reinforcing tape portion 2, the latter being firmly attached to the flap A by way of its entire undersurface. Therefore, not only the cover flap A but also the main tape portion l is properly reinforced to prevent any tearing even if the main tape portion is pulled very strongly when unsealing the box or container. This feature presents a superior effect in practical use.

lt will be noted that all adhesive layers of the composite sealing tape are protected from the effects of ambient air while in storage or in use. it is well known that any tape which has its adhesive layer or layers protected from air before or after its use is capable of being used repeatedly and for a prolonged period. The inventive sealing tapes satisfy this requirement.

No specific data were given herein in regard to the kind of adhesives, releasing agents and other substances that may be used in practicing the invention, and also in regard to specific grades of materials which are best suited for purposes of the inventive composite sealing tapes. it should be noted, however, that these characteristics, materials and other details are well known to those skilled in the art, and no protection is sought for these expedients beyond the features explained hereinabove and set forth in the claims. Very good results were obtained with commercially available pressure-sensitive adhesives and releasing agents such as for exam le, those made according to the U. Pats. 2,971,863 and 987,420,

and/or German lPat. 855,746, fully identified in the introduction of this application.

it should also be understood that the foregoing disclosure relates only to preferred embodiments of the invention, and that it is intended to cover all changes and modifications of the examples described which do not constitute departures from the spirit and scope of the invention as set forth in the appended claims.

What we claim is:

11. A reusable composite sealing tape for releasably interconnecting container parts (and the like), comprising a main tape portion cut to a suitable length and width, and an at least partly coplanar reinforcing tape portion, the undersurfaces of said tape portions being coated with a pressure-sensitive adhesive, said tape portions having substantially aligned free ends, the inner end of said reinforcing portion being turned up so that the undersurfaces of said main and said reinforcing portions at least partly face each other, thereby the turned-up reinforcing end portion being firmly attached to the undersu r face of the midportion of said main tape portion, the latter having a first area adapted to be attached to one side of a first container part, while a second area of said main portion, including its free end, is adapted to be attached to a second container part which should be releasably interconnected with the first container part, by the application of manual pressure to said first and said second areas when placed on the respective first and second container parts, said reinforcing portion being at least partly attachable to the opposite side of the first container part by similar pressure applied therebetween.

2. The sealing tape as defined in claim 1, wherein said main portion has a mark applied to its top surface, in the area of said midportion to which said inner end of the reinforcing por tion is attached, for indicating a third area of said main portion which is to be located edgewise between said one and said opposite sides of the first container part when the sealing tape is applied thereto.

3. The sealing tape as defined in claim ll, further comprising a picking tab at said free end of the main portion, for facilitating the separation of said main and said reinforcing portions.

4. The sealing tape as defined in claim 3, wherein said picking tab is constituted by a turned-in terminal portion of said free end of the main portion.

5. The sealing tape as defined in claim ll, wherein said un dersurfaces of the main and reinforcing portions face each other at said midportion, said turned-up reinforcing portion and an adjoining section of said reinforcing portion constituting hinge means for said first area of the main portion when the same is attached to the first container part.

6. The sealing tape as defined in claim 5, further comprising an auxiliary tape portion, at least partly coplanar with said main and said reinforcing portions, and applied below said reinforcing portion.

7. The sealing tape as defined in claim 6, further comprising at least one length of backing material initially and at least partly attached to the respective exposed undersurfaces of said tape portions.

ii. The sealing tape as defined in claim 5, further comprising an auxiliary tape portion, at least partly coplanar with said main and said reinforcing portions, and inserted therebetween.

9. The sealing tape as defined in claim ti, wherein the inner end of said auxiliary portion is inserted into the space formed by said turned-up reinforcing end portion.

lit. The sealing tape as defined in claim 8, wherein the free end of said reinforcing portion projects beyond the free end of said auxiliary portion.

ll 11. The sealing tape as defined in claim 8, wherein the inner end of said auxiliary portion is spaced apart from said turnedup reinforcing portion along said midportion of the main end portion.

UNITED STATES PATENT AND TRADEMARK OFFICE CERTIFICATE OF CORRECTION PATENT N0. 3,616,114

DATED October 26,1971

|NVENT0R(5) I Tsuneji Hamaguchi et al.

It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

In Column 4, line 48, "showing how centerline fourth" should read showing how the exemplary fourth In Column 5, line 37, "This will threefold effect for the edge of flap B" should read This will produce a reinforcing effect for the edge of the flap B In Column 6, line 13, Claim 1, "and the like" should be deleted.

Signed and Scaled this Twenty-second D y f November 1977 [SEAL] A nest:

RUTH C. MASON LUTRELLE F. PARKER Arresting Officer Acting Commissioner of Patents and Trademarks

Claims

2. The sealing tape as defined in claim 1, wherein said main portion has a mark applied to its top surface, in the area of said midportion to which said inner end of the reinforcing portion is attached, for indicating a third area of said main portion which is to be located edgewise between said one and said opposite sides of the first container part when the sealing tape is applied thereto.
3. The sealing tape as defined in claim 1, further comprising a picking tab at said free end of the main portion, for facilitating the separation of said main and said reinforcing portions.
4. The sealing tape as defined in claim 3, wherein said picking tab is constituted by a turned-in terminal portion of said free end of the main portion.
5. The sealing tape as defined in claim 1, wherein said undersurfaces of the main and reinforcing portions face each other at said midportion, said turned-up reinforcing portion and an adjoining section of said reinforcing portion constituting hinge means for said first area of the main portion when the same is attached to the first container part.
6. The sealing tape as defined in claim 5, further comprising an auxiliary tape portion, at least partly coplanar with said main and said reinforcing portions, and applied below said reinforcing portion.
7. The sealing tape as defined in claim 6, further comprising at least one length of backing material initially and at least partly attached to the respective exposed undersurfaces of said tape portions.
8. The sealing tape as defined in claim 5, further comprising an auxiliary tape portion, at least partly coplanar with said main and said reinforcing portions, and inserted therebetween.
9. The sealing tape as defined in claim 8, wherein the inner end of said auxiliary portion is inserted into the space formed by said turned-up reinforcing end portion.
10. The sealing tape as defined in claim 8, wherein the free end of said reinforcing portion projects beyond the free end of said auxiliary portion.
11. The sealing tape as defined in claim 8, wherein the inner end of said auxiliary portion is spaced apart from said turned-up reinforcing portion along said midportion of the main end portion.