GB1583980A - Tabbed lid for container - Google Patents

Description

(54) TABBED LID FOR CONTAINERS (71) We, CARNAUD S.A., a French Body Corporate, of 65, avenue Edouard Vaillant, Boulogne-sur-Seine (Hauts-de-Seine), France, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The present invention relates to improvements in tabbed or lugged lids or covers for containers, such a paint pails and buckets and canisters for foodstuffs.

Known lids and covers of this type are designed so that the central panel nests inside the container body and the crimping tabs or lugs defined in a notched peripheral skirt extend over the outer rolled rim of the container body; once the container has been filled and the lid or cover positioned thereon the crimping tabs or lugs are deformed inwardly engaging under the rolled rim of the container body.

The tabs or lugs define, with alternating cutouts, the notched peripheral skirt of the lid or cover, the lower ends of the tabs or lugs being slightly turned up to provide an engagement zone for accommodating a prying implement to swing the tabs or lugs upwardly and outwardly out of contact with the container body to open the container once the lid has been crimped thereto.

Such lids or covers undergo much handling including stacking, storage and shipment, even before they are positioned and crimped on containers after the latter have been filled.

Now, because of their structure and the manufacturing processes employed such lids or covers have sharp, cutting edges, namely at the lower edge of the turned up lower ends of the tabs or lugs and along the longitudinal edges of the lugs, liable to come into contact with the user's fingers and therfore potentially dangerous.

An object of the invention is to put these potentially dangerous edges out of the normal reach of the user's fingers, without the fluidtightness of the eventual closed container, the good impact resistance of the lid or cover and, secondarily, the esthetics of the container with its crimped lid or cover being adversely affected.

The invention not only reconciles these various aims but it affords-while providing safer handling, which is its main object-a surprising unexpected improveent in respect of fluid-tightness, impact shock resistance and design.

According to the present invention there is provided a lid for a container having a body and a rolled-rim at an open end of the body, said lid comprising a central panel inset with respect to the top end surface of its notched peripheral skirt so that when the lid is in posi tion on the open end of the container the central panel fits inside the container body while the peripheral skirt extends over the rolled rim of the container, said peripheral skirt defining a plurality of uniformly spaced crimping tabs or lugs alternating with cut outs, said lid being securable to the container by crimping the tabs or lugs under the rolled rim, the lower ends being turned up for accommodating a prying implement to swing the tabs or lugs upwardly and outwardly, wherein the lid has a diameter of at least 160 mm, the ratio of the mean circumferential extent of the tabs or lugs measured along a given circumference with respect to the mean circumferential extent of the cutouts there between is at least 6, and the mean circum ferential extent of each of the cutouts is less than 8 mm.

Preferably, the mean circumferential extent of each of the cutouts is in the vicinity of 6 mm.

Preferably, the lower ends of the tabs or lugs are rolled radially on themselves about a small radius so that the free lower edges of the tabs or lugs are directed towards and in close proximity to the plain cylindrical wall of the peripheral skirt. The lower ends of the tabs or lugs are preferably rolled on themselves through an angle in the order of 270 , the distance between the lower edge and the facing plain cylindrical wall of the skirt being, at most, as large as the radius of the rolled lower end.

The advantages afforded by the invention as regards handling safety will be appreciated; indeed, the rolled lower ends of the tabs or lugs permit the introduction of a prying im plement but preclude the user's fingers from being caught, in the course of handling the lid or cover, be it alone or in position on its container.

Further, the reduced circumferential extent of the tabs or lugs prevents the user's finger from coming into contact with the sharp longitudinal edges of the crimping tabs or lugs.

It should be pointed out, moreover, that the radial inward taper of the portions of the tabs or lugs below the rolled rim of the container therefore further diminishes the chance of the user's finger touching sharp edges.

With a lid or cover according to the invention it is still possible to open the container closed by the lid or cover by prying the tabs or lugs outwardly by inserting a prying implement (e.g. a screwdriver) between the plain cylindrical wall of the tab or lug and the curl or rolled lower end thereof.

From the point of view of fluid-tightness and shock resistance, the present lid or cover produces new, unexpected results; indeed, the increased circumferential dimensions of the tabs or lugs permits the lid or cover to sit better on the container- and considerably enhances the fluid-tightness owing to the reduc tion of the pitch or inter-lug spacing, defined by the cutouts, where known lids or covers were not crimped, and the impact resistance, especially drop impact resistance. More -detailed data on this point appears in the following description.

It is also preferable that the lugs should be so configured that after crimping the adjacent longitudinal edges of consecutive lugs are substantially parallel. This precludes the formation of flaring cutouts which, even if they are of narrower circumferential extent, would create an added risk, of injury to the user's fingers.

Of advantage is the provision of a flaring zone in each lug comprising a frustoconical panel which serves an an abutment surface when stacking lids on one another for storage or transport.

The frustoconical panel limits the degree of nesting of stacked lids or covers thereby obviating jamming, and besides, it helps, after unstacking, the centring of the lid or cover on the rolled rim of the container body.

Other features and advantages of the invention will be brought out in the description which follows, by way of non-limiting example, of an embodiment of the invention, -with reference to the accompanying drawings in which: Figure 1 is a side elevational view of a prior art lid or cover; Figure 2 is a fragmentary sectional view taken along the line II-II in Figure 1; Figure 3 is an elevatiònal view similar to that of Figure 1 for a lid or cover embodying the present invention; Figure 4 is a sectional view of the lid or cover in Figure 3; Figure 5 is a sectional view similar to that of Figure 4 in which the lid or cover has been crimped on its container.

For the sake of simplicity, the description will be limited to the features of the invention which distinguish it from the prior art, one having ordinary skill in the art being readily able to apply them directly in light of the prior art.

Also, directional terms such as "lower", "upper", "downwardly" used herein are likewise employed for the sake of simplicity with respect to the illustrated orientation of the lid; it is obvious that these terms are not intended to limit the features of the invention to this particular orientation of the lid and container.

In order to better understand the invention Figures 1 and 2, representing a prior art lid or cover, will be described briefly.

There is shown a cover, designated overall by reference numeral 1 comprising a central panel 2 inset with respect to the top end of the peripheral skirt 3. The skirt is uniformly notched to form tabs or lugs 4 between alternating cutouts 5. The free lower edge 6 of each tab or lug is bent upwards into an upwardly opening rolled lower end or curl 7. As it is known-and shown in Figure 5 with respect to the lid or cover according to the invention-the cylindrical walls 8 of the tabs or lugs are deformed under the rolled rim of the associated container during the crimping -operation. The curl 7 is thus very readily adapted to engage a prying implement, such as a screwdriver, which is fulcrumed against the top 9 of the cover in order to lift the lugs, one by one, sufficiently to release the lid or cover.

As the lid or cover is produced by stamping out a blank, it is evident that it will have sharp edges along its entire cut-out contour, particularly at the free edge of the curl 7 and along the edges 11, 12 delimiting the walls of the lugs 4. These are precisely the portions of .the lid or cover the user's hands are most likely to come into contact with during various stages of handling the lid or cover itself or once on the container.

Reference is now made to Figures 3, 4 and 5 illustrating various features of the lid or cover according to the invention. Like parts bear the same reference numerals as before.

For a given pitch or inter-lug spacing P, it will be noted that the circumferential extent L of the lugs is clearly greater than the circum lerenilal extent of the cutouts or notches - 5 therebetween; the likelihood of one's fingers coming into contact with the sharp edges 11 and 12 of the lugs is virtually excluded. The dimensions L and L1 are, of course, measured along the same circumference, for instance as shown in Figure 3, where the skirt 8 merges into the curl 7.

Tests have revealed that the circumferential extent L, of the notches or cutouts should be less than 8 mm and preferably in the vicinity of 6 mm.

The minimum circumferential extent of the notches or cutout is, moreover, determined so as to avoid overlapping of the lugs, bearing in mind the fact that the cutouts or notches narrow after crimping.

The value of L1 being determined as afunction of the foregoing considerations, the ratio L/L1 of the mean circumferential extens of the lugs and cutouts or notches is greater than or equal to 6.

It has been established in the course of testing that an L/L1 ratio of 6 is suitable for lid or cover diameters in the range of 160 to 180 mm; for diameters greater than 300 mm an L/L1 ratio of 8- has proved to be more suitable. This ratio will be maintaind for very large diameters, the number of tabs or lugs are simply increased.

Each curl 7 having its free lower edge 13 facing the plain cylindrical wall 8 of its lug (Figure 4), the gap E being adequate to re-ceive a prying implement. In general, the free lower edge 13 is rolled through about 270 ; the gap E, for its part, is set at a value equal to or less than the radius of the curl.

The position of the edge 13 thus prevents any accidental contact by the user's hand before the lid or cover is received on the container and after crimping.

The lugs 4 are cut out so that after crimping the longitudinal edges 11, 12 delimiting the walls 8 are substantially parallel thereby eliminating the sharp, rounded corner 14 (Figure 1), each curl having circumferential extent which closely approximates that of the rest of the lug.

The curl may be formed, as is known in the art, by die striking, preferably combined with the crimping step to save a forming pass.

Apprpriate shape and displacement of the crimping tool for this purpose are known to one having ordinary skill in the art.

Figure 5 illustrates the crimped lid or cover in position on its associated container; the container body 15 having a rolled rim 16 on to which the skirt 3 is crimped by radial deformation of the wall 8 under the rolled rim 16. In these circumstances the sharp free edge 13 of the curl 7 is altogether out of contact with the user's fingers.

As mentioned above, the reduction of the breaks in continuity of the crimped surface improves the securement of the lid or cover and fluid-tightness of the filled and closed container; tests have shown that fluid-tightnes is more than double that of prior art lids or covers. This improvement manifests itself particularly at the top end of the container body's vertical seam ;it is a fact that rolled rim of the container body may weaken at his location. Owing to its characteristics, as defined hereinabove, the present lid or cover provides, after crimping, better securement of the lid or cover on the container body and sharply attenuates the likelihood of leaking.

This reinforced grip of the cover enhances, equally surprisingly, the resistance to accidentally wrenching off the lid pr cover due to impact or dropping. Systematic drop tests,even at heights greater than normally required, established that the resistance of cover containers taught here are bettered by at least a factor of 2.

The dimensions of the cutouts and the ratio of the circumferential extents of lugs and cutouts aim at optimising tht following factors: -securement of the cover to the container; -force needed to open the dosed container; -prevention of the overlapping of the lugs; -prevention of the formation of peripheral cracks and tears in the metal at - the- closed ends of the cutouts or notches.

Handling hazards of prior art lids or covers of the present type anifest themselves especially during the manual separation of stacked covers, due to their jamming in immediately subjacent lids or covers; this shortcoming precluded, moreover, automated unstacking of lids or covers.

Figure 3 and 4 show a lid or cover which, in addition to the features already set forth, overcomes this difficulty too.

There is provided at 17 a flaring zone comprising a frustoconical panel 18 which flares downwardly; this panel 18 forms an abutment for the curl of a superposed lid or cover during stacking, thereby preventing jamming. Further, this frustoconical panel aids in centring the lid or cover relative to the rim of its associated container.

WHAT WE CLAIM IS 1. A lid for a container having a body and a rolled rim at an open end of the body, said lid comprising a central panel inset with respect to the top end surface of its notched peripheral skirt so that when the lid is in position on the open end of the container the central panel fits inside the container body while the peripheral skirt extends over the rolled rim of the container, said peripheral skirt defining a plurality of uniformly spaced crimping tabs or lugs alternating with cutouts, said lid being securable to the container by crimping the tabs or lugs under the rolled rim, the lower ends being turned up for accommodating a prying implement to swing the tabs or lugs upwardly and outwardly, wherein the lid has a diameter of at least 160 mm, the ratio of the mean circumferential extent of the tabs or lugs measured along a given circumference with respect to the mean circum

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (11)

**WARNING** start of CLMS field may overlap end of DESC **. along the same circumference, for instance as shown in Figure 3, where the skirt 8 merges into the curl 7. Tests have revealed that the circumferential extent L, of the notches or cutouts should be less than 8 mm and preferably in the vicinity of 6 mm. The minimum circumferential extent of the notches or cutout is, moreover, determined so as to avoid overlapping of the lugs, bearing in mind the fact that the cutouts or notches narrow after crimping. The value of L1 being determined as afunction of the foregoing considerations, the ratio L/L1 of the mean circumferential extens of the lugs and cutouts or notches is greater than or equal to 6. It has been established in the course of testing that an L/L1 ratio of 6 is suitable for lid or cover diameters in the range of 160 to 180 mm; for diameters greater than 300 mm an L/L1 ratio of 8- has proved to be more suitable. This ratio will be maintaind for very large diameters, the number of tabs or lugs are simply increased. Each curl 7 having its free lower edge 13 facing the plain cylindrical wall 8 of its lug (Figure 4), the gap E being adequate to re-ceive a prying implement. In general, the free lower edge 13 is rolled through about 270 ; the gap E, for its part, is set at a value equal to or less than the radius of the curl. The position of the edge 13 thus prevents any accidental contact by the user's hand before the lid or cover is received on the container and after crimping. The lugs 4 are cut out so that after crimping the longitudinal edges 11, 12 delimiting the walls 8 are substantially parallel thereby eliminating the sharp, rounded corner 14 (Figure 1), each curl having circumferential extent which closely approximates that of the rest of the lug. The curl may be formed, as is known in the art, by die striking, preferably combined with the crimping step to save a forming pass. Apprpriate shape and displacement of the crimping tool for this purpose are known to one having ordinary skill in the art. Figure 5 illustrates the crimped lid or cover in position on its associated container; the container body 15 having a rolled rim 16 on to which the skirt 3 is crimped by radial deformation of the wall 8 under the rolled rim 16. In these circumstances the sharp free edge 13 of the curl 7 is altogether out of contact with the user's fingers. As mentioned above, the reduction of the breaks in continuity of the crimped surface improves the securement of the lid or cover and fluid-tightness of the filled and closed container; tests have shown that fluid-tightnes is more than double that of prior art lids or covers. This improvement manifests itself particularly at the top end of the container body's vertical seam ;it is a fact that rolled rim of the container body may weaken at his location. Owing to its characteristics, as defined hereinabove, the present lid or cover provides, after crimping, better securement of the lid or cover on the container body and sharply attenuates the likelihood of leaking. This reinforced grip of the cover enhances, equally surprisingly, the resistance to accidentally wrenching off the lid pr cover due to impact or dropping. Systematic drop tests,even at heights greater than normally required, established that the resistance of cover containers taught here are bettered by at least a factor of 2. The dimensions of the cutouts and the ratio of the circumferential extents of lugs and cutouts aim at optimising tht following factors: -securement of the cover to the container; -force needed to open the dosed container; -prevention of the overlapping of the lugs; -prevention of the formation of peripheral cracks and tears in the metal at - the- closed ends of the cutouts or notches. Handling hazards of prior art lids or covers of the present type anifest themselves especially during the manual separation of stacked covers, due to their jamming in immediately subjacent lids or covers; this shortcoming precluded, moreover, automated unstacking of lids or covers. Figure 3 and 4 show a lid or cover which, in addition to the features already set forth, overcomes this difficulty too. There is provided at 17 a flaring zone comprising a frustoconical panel 18 which flares downwardly; this panel 18 forms an abutment for the curl of a superposed lid or cover during stacking, thereby preventing jamming. Further, this frustoconical panel aids in centring the lid or cover relative to the rim of its associated container. WHAT WE CLAIM IS

1. A lid for a container having a body and a rolled rim at an open end of the body, said lid comprising a central panel inset with respect to the top end surface of its notched peripheral skirt so that when the lid is in position on the open end of the container the central panel fits inside the container body while the peripheral skirt extends over the rolled rim of the container, said peripheral skirt defining a plurality of uniformly spaced crimping tabs or lugs alternating with cutouts, said lid being securable to the container by crimping the tabs or lugs under the rolled rim, the lower ends being turned up for accommodating a prying implement to swing the tabs or lugs upwardly and outwardly, wherein the lid has a diameter of at least 160 mm, the ratio of the mean circumferential extent of the tabs or lugs measured along a given circumference with respect to the mean circum

ferential extent of the cutouts therebetween is at least 6, and the mean circumferential extent of each of the cutouts is less than 8 mm.

2. A lid as claimed in Claim 1, wherein the mean circumferential extent of each of the cutouts is about 6 mm.

3. A lid as claimed in Claim 1 or 2, wherein the lower ends of the tabs or lugs are rolled to a small radius, the free lower edges of the tabs or lugs facing and spaced from plain cylindrical walls thereof.

4. A lid as claimed in Claim 3, wherein the free lower edges of the tabs or lugs are rolled through about 270".

5. A lid as claimed in Claim 3 or 4, wherein the generally radial distance between the free lower edges of the tabs or lugs and the facing plain cylindrical walls thereof is not greater than the radius of the rolled lower ends of the tabs or lugs.

6. A lid as claimed in any of the preceding claims, wherein the longitudinal edges of the tabs or lugs are cut out to such a contour that when the lid is crimped to the container adjacent longitudinal edges of two consecutive tabs or lugs are substantially parallel to each other.

7. A lid as claimed in any of the preceding claims, further comprising a downwardly flared zone in the middle of the cylindrical wall of the peripheral skirt adapted to abut against a superjacent lid when said lids are stacked.

8. A container having a lid according to any of the preceding claims.

9. A container having a lid according to any of the preceding claims, crimped thereto.

10. A lid substantially as herein described with reference to or as illustrated in Figures 3 and 4, or as modified by Figure 5.

11. A container having a lid as herein described with reference to or as illustrated in Figure 5. ~~