Abstract: A double-walled container and method of manufacturing are disclosed. A first container having a smaller diameter than a second container is inserted into the second container. A portion of the first container is expanded and/or a portion of the second container may be narrowed so that first and second container is interlocked and form a double-walled container. The first and/or second containers may have ribs. An air gap between the first and second containers provides thermal insulation to contents of the double-walled container.

Abstract: A can lid of a can provided with an easily openable opening means is disclosed wherein the can lid is equipped with a can lid which is fastened by winding tightly on the can main body and the top end opening of the can main body, a score section installed around the territory of the prearranged opening area and a tab for severing the score section. In the can lid, there is formed a protrusion protruding upward from the can lid in front of the can opening during manufacturing of the can lid, in which it is a collapsing protrusion where the protrusion elastically deforms into the can main body by depressing motion of the user and thereby enables forming of a concave section for easy insertion of the user's finger.

Abstract: A beverage container includes a can body having a side wall, a neck portion of reduced diameter, a closure lid and an anchor structure on the closure lid. The anchor structure is offset with respect to the center of the lid. A pull tab has a mounting hole which fits onto the anchor structure. One end of the pull tab has a grip handle, and the other end has a puncturing nose. The pull tab is turnable on the anchor structure, and thus also turnable with respect to the closure lid. The pull tab is of a length whereby it normally just fits between the opposite locations of a peripheral groove on the closure lid. The pull tab can be manually turned from a first position overlying the closure lid, to a second position wherein it overhangs one part of the peripheral groove. The construction thus provides an extended handle length to permit the user to more easily grasp and raise the pull tab, and open the container, for use.

Abstract: A beverage can end is described. The beverage can end has a curl defining a perimeter of the can end, a chuckwall extending downwardly and radially inwardly from the curl, and a transition wall joining the chuckwall to an outer peripheral edge of a center panel. The transition wall is formed in compression such that a portion of the transition wall exhibits a compressed segment having a thickness which is 1% to 20% thicker than a thickness of the center panel.

Abstract: An improved convenience closure that is adapted for sealing an end of a can includes an end panel having a peripheral score, a rivet formation, a mustache score and a flex line score defined therein. The mustache score may include a central portion that is positioned radially inwardly on the end panel relative to the rivet formation. The central portion is preferably curved, with a concave side of the curvature facing the rivet formation. The mustache score also may include first and second preferably symmetrical end portions, each of which is continuous with the central portion. Most of the total length of each of the end portions may be curved away from a nearest portion of the peripheral score, with a convex side of curvature facing the nearest portion of the peripheral score. Tooling for making the convenience closure and a method of making such a convenience disclosure are also disclosed.

Abstract: The present invention is a cap covering for a punch-key tab rotably attached to the top of a preformed can, wherein the punch-key tab is to be utilized by a person to punch out a prepared flap seal in the can top along a predefined scored boundary. The cap covering includes an attachable and detachable hollow casing which can be fitted on-demand onto the handle of a punch-key tab. The invention will distinguish individual ownership among identical cans of beverage; will serve as a closure to aid in keeping the carbonation (if any) in the beverage; will aid in maintaining the beverage at the desired drinking temperature; and will act in minimizing spillage, keep bugs and debris out, and in keeping the beverage in an unadulterated state.

Abstract: The invention relates to a fuel paste tin, comprising a dished tin body (1) and a sealing lid (3), fixed to the tin body (1) with two pre-scored lines (6), along which a partial lid section (7) may be removed from the sealing lid (3) by breaking a material connection to generate a precisely defined opening (4, 10, 11) in the sealing lid (3). The invention permits the production of fuel paste tins with may be employed directly as paste burners with a desired burn capacity and burn duration, which are economic to produce and cause little litter.

Abstract: A can end for a two-piece beverage can is described. The can end has a center panel positioned about a vertical center axis. The center panel has a stay-on tab opening assembly located on a public side. A reinforcing bead surrounds the center panel. The reinforcing bead has an inner curved portion having a radius of curvature located radially inwardly from an outer curved portion having a radius of curvature. The radius of curvature of the outer curved portion is greater than the radius of curvature of the inner curved portion.

Abstract: The present disclosure is directed to a beverage container having an opening assembly apparatus and method having an advanced design for sealing the contents within the container after opening. The opening assembly includes a lid having a top and bottom side, the lid being attached to a receptacle for containing the beverage contents, and a recess located about the top side of the lid for facilitating the filling of the receptacle. An aperture is located about the recess and projecting from the aperture is an undulating flange on the bottom side of the lid. A closure member coactively engaging the aperture and recess to provide a sealing engagement by inserting a first portion of the closure member into the recess and a second portion of the closure member into the aperture and rotating the closure member from an opened position to a closed position. The closure member includes a breakable seal for providing security that the container is tamper free.

Abstract: The present invention describes a beverage can end which utilizes less material and has an improved internal buckle strength based on the geometric configuration of a chuck wall, inner panel wall and central panel, and which, in one embodiment utilizes an arcuate shaped chuck wall with a radius of curvature between about 0.150 inches and 0.250 inches with at least one transition zone positioned between an upper and lower end of the chuck wall.

Abstract: The invention relates to a positional fixing of a tab on a sheet metal lid comprising a panel (10) and a seamable edge (12) surrounding said panel, suitable for attaching to a can body. On the panel (10), an openable area is defined by a weakening line (16), and outside said openable area (17), a tab (30,31,32,33) is provided at a mounting place (11). Said tab (30) comprises a grip portion (32), an opening portion (33), and an attaching portion (31), said latter being provided for attaching said tab substantially parallel with respect to said panel (10). Said tab (30) as attached is disposed with its opening portion (33) above said openable area (17). Close to at least one edge (31c) of the attaching portion (31), a strip-shaped projection (21a, 21b, 20) is shaped to protrude out of said panel (10), for limiting a pivoting movement (?) of said tab (30) around said mounting place (11).

Abstract: A can end for a container has a curl defining an outer perimeter of the can end. A chuckwall extends downwardly from the curl. A means for increasing the strength of the can end is integral with the chuckwall, and a center panel is integral with the means for increasing the strength of the can end. The center panel has a product side, a public side, a rivet, and a displaceable tear panel. A non-detachable tab is staked to the central panel wall by the rivet. First and second void regions of the tab are separated by a narrow strip of the central webbing. A portion of the narrow strip extends downwardly and approaches the public side of the central panel wherein a height of the lift end of the tab above the public side of the central panel is maintained at a predetermined height.

Abstract: An improved convenience closure that is adapted for sealing an end of a can includes an end panel having a peripheral score, a rivet formation, a mustache score and a flex line score defined therein. The mustache score may include a central portion that is positioned radially inwardly on the end panel relative to the rivet formation. The central portion is preferably curved, with a concave side of the curvature facing the rivet formation. The mustache score also may include first and second preferably symmetrical end portions, each of which is continuous with the central portion. Most of the total length of each of the end portions may be curved away from a nearest portion of the peripheral score, with a convex side of curvature facing the nearest portion of the peripheral score. Tooling for making the convenience closure and a method of making such a convenience disclosure are also disclosed.

Abstract: An opening assembly that provides a beverage can with the ability to be closed once opened. The opening assembly allows a user to open and close a beverage can while protecting the integrity of the can, thus providing an improved beverage can that has the ability to seal-in carbonation.

Abstract: A reclosable metal container in the style of a bottle-shaped can has a conventional can body of steel or aluminum to which a metal neck component is seamed. A sleeve of plastics fits over the neck component and a detent inside the sleeve clips it onto the seam. The upper edge of the sleeve is fixed in place by a curl on the upper edge of the neck component. By using a separate neck component and hiding the seam under a sleeve, conventional sizes and material gauges can be used for the can body. Thicker material may be used for the neck component in order to withstand necking forces. Threads for closing the container may be provided either on the sleeve or, in an embodiment where the sleeve is simply used to cover the seam, on a cylindrical part of the neck component itself.

Abstract: A carton for containing a plurality of articles. The carton has panels that extend at least partially around an interior of the carton. The panels comprise a top panel, a bottom panel and a first side panel and a second side panel. The carton has a dispenser for allowing access to the articles in the carton. The dispenser has a dispenser panel that is at least partially defined by a tear line in the carton and is for being at least partially removed for at least further opening a dispenser opening. The carton can also have a curved end.

Abstract: A beverage can cap member (16, 100) is configured so that its exterior surface (28) extending radially inwardly from the rim (18) or rim forming portion (140) is substantially flat or continuous, or has a slight curve from a position adjacent from the rim (18) or rim forming portion (140). The cap member (16, 100) may have a countersink (160) which is filled with a filler material including a curable adhesive, an insert (180) of a natural or synthetic material or the like. The filler material increases the structural strength of the cap member (16, 100) to an extent that it can be made of a relatively thinner material and still complies with the minimum peaking pressure of the industrial standard.

Abstract: A beverage container having multiple openings for enhancing the enjoyment of a beverage is disclosed. The container has openings for drinking or emptying a beverage or liquid, in addition to openings designed for experiencing the aroma of a contained beverage. A modified pull-tab is present for manipulating the drink and aroma openings without bending or otherwise deforming. The container can take the form of a one-use container or a refillable, travel-type container having a removable cover.

Abstract: The invention includes a novel profile for a container bottom. The bottom structure includes a domed central panel attached at its outside edge to a downwardly projecting substantially cylindrical inner leg portion. The inner leg portion is attached to a generally semi-circular nose portion. The outside of the nose portion is attached to an upwardly and outwardly inclined outer leg portion. The outer leg portion is attached to an outwardly inclined peripheral portion. The peripheral portion is attached to the lower end of the generally cylindrical sidewall portion. The improvement primarily involves the larger stand diameter, and altered dome circle radius and dome depth, which produces a container bottom profile yielding more consistent results in drop tests to determine resistance to bulging and reversals (single can and consumer package flat and angled drop tests) than prior art can bottoms.

Abstract: A device is disclosed for re-closing an opening in a can having a tab opener. The device comprises a mount piece having an overall shape and flexibility that enables it to be pushed through at least one aperture formed in the tab opener thereby securing the device to the tab opener. The device further comprises a plug portion attached to the mount piece and configured to engage and at least partially close an opening in the can.

Abstract: The present invention generally relates to a flexible tab used to open beer/beverage can ends and food can ends. The tab has a plurality of slots provided in about a middle part of the tab between a nose portion and a lift portion on opposing sides of the tab. The slots combine to form a fulcrum that extends generally transverse to an axis that passes along a length of the tab. The fulcrum allows the lift portion to pivot upwards and downwards in relation to the nose portion. The tab also has a paneled or beaded area adjacent to the slots at about the middle part of the tab. Tooling for the manufacture of the flexible tab is also provided. A method for manufacturing the flexible tab is additionally provided as well.

Abstract: Can and bottle covers include a can cover and a bottle cover. The can cover includes a cover portion, a rim portion and a tab portion. One end of the cover portion is inserted under a pull tab of a pop top can. The rim portion connects the other end of the cover portion with one end of the tab portion. The tab portion is inserted, under the pull tab to open the pop top can. The bottle cover includes a cover portion, a neck portion and a web portion. A slot is formed in one end of the neck portion. The slot is sized to be received by a neck end of a bottle. The web portion connects the cover portion with the neck portion. A neck projection is preferably formed in the cover portion. The neck projection is retained in an inner perimeter of the neck end.

Abstract: The invention covers a number of alternative improvements to the prior art pull-tab used to open container such as soda cans. One improvement is by forming the nose of the pull tab at a certain angle to the body of the tab, thus allowing the user to tilt the tab thus lifting the pull tip higher and providing more room for the user to insert the finger tip under the pull tip thus making it easier to open the container. Another improvement is by rotating the pull tab a certain angle and making it follow a caming surface thus lifting the pull tip and again providing more room to insert the finger tip and making it easier to open the container.

Abstract: A tab is used to open beer/beverage can ends and food can ends. The tab has one or more arcuate strips that are provided on a surface of the tab proximate to a peripheral surface of the tab where the one or more arcuate strips have been formed further into a preselected portion of curled or hemmed portions of the tab. Tooling for the manufacture of the tab is also provided. A method for manufacturing the tab is additionally provided as well.

Abstract: An easy open can end has an improved structure for facilitating the opening operation of the tear panel, a method of further forming a can end to have the improved structure, and tooling for accomplishing the method. The further formation of the can end is particularly useful in easy-open can ends having enlarged tear panels.

Abstract: A can end having a countersink bead, an inclined chuck wall and a strong seam, resists distortion from its circular profile when subjected to thermal processing or when packaging carbonated beverages. This high hoop strength affects the manner in which the can end ultimately fails when placed under extreme abuse conditions, even if buckle pressure performance is within industry specified standards. The can end of the invention has control features introduced which control the failure mode while maintaining specified buckle pressure performance. In one embodiment, the can end has a two part wall and a control feature that comprises expansion of the countersink bead to act as a trigger for local peaking, together with a groove in the chuck wall which prevents the peaking force from being concentrated at a single point which could result in leaking by the production of a pin hole.

Abstract: The present invention relates to an opening device for a can, which is constructed such that the contents of the can flow out and exterior air is simultaneously introduced into the can. The opening device of the present invention comprises first and second opening portions 122 and 124 through which the contents flow out and the exterior air is introduced into the can upon opening thereof, respectively, and which are disposed to be opposite to each other at both sides of the top surface 110 of the can and defined by incision lines 122a and 124a so that a part of each of the opening portions is attached to the top surface; and a tab 140 mounted on the top surface of the can by means of a first rivet stub Ra installed outside of the first opening portion and a second rivet stub Rb installed within the second opening portion.

Abstract: Re-closable lid, in particular for a drinks can, with a cutout portion (13a), which is provided in the lid plate (11) and is bounded by a predetermined breaking line (12), and also an opener tab (14), which is pivoted mounted on the lid plate (11) for breaking open the predetermined breaking line. The fastening tongue (16) of the opener tab (14) has a freely twistable portion (16a) and, on the underside of the gripping portion (18) of the opener tab (14), there is formed a flat closure attachment (31), which fits into the opening (13b) produced by breaking open the predetermined breaking line (12) and is formed for re-closing the opening (13b).

Abstract: Drawn and ironed aluminum can bodies are made from aluminum having a gauge thickness of 0.01075 inches or less, in which the bottom profile meets customer requirements for bottom performance in terms of buckle, drop and growth, without requiring the bottom profile to be reformed in a separate bottom profile reforming step.

Abstract: The invention relates to a container with a closing device. Said container comprises a base, a lid (C) and a vertical partition joining the base and the lid, a tongue element comprising a grip end (4) and an opposite bearing end (8), said tongue element (4,8) comprising a lug (3), being integral with the lid (C) by means of a plug (2) fixed to the lid (c). The tongue can be rotationally displaced around the longitudinal axis XX of the plug (2) and can be inclined at a certain angle ? in relation to the plane of the lid, an opening zone (1) being defined by a precut (10) in said lid (C) and being able to be opened using the tongue, whereby the bearing end thereof (8) exerts a force from the outside to the inside of the container on said area (1) defined by the precut (10).

Abstract: A plastic resealable closure includes a base plate affixed to a can, a middle plate having a plug, and a top plate having a support ring. The support ring expands or supports the plug to enhance sealing. The top plate includes prongs that are insertable into recesses on the base plate to enhance closing. The closure is applied without heating of the tool or the closure.

Abstract: A can end having a countersink bead, an inclined chuck wall and a strong seam, resists distortion from its circular profile when subjected to thermal processing or when packaging carbonated beverages. This high hoop strength affects the manner in which the can end ultimately fails when placed under extreme abuse conditions, even if buckle pressure performance is within industry specified standards. The can end of the invention has control features introduced which control the failure mode whilst maintaining specified buckle pressure performance. In one embodiment, the control feature comprises expansion of the countersink bead to act as a trigger for local peaking, together with a groove in the chuck wall which prevents the peaking force from being concentrated at a single point which could result in leaking by the production of a pin hole.

Abstract: My invention is an improvement on a two piece can end that will not have a pull Tab on it; on like the ones being used today on beverage cans such as beer, pop or any other product that my improvement can be applied to.

Abstract: A container can be easily opened, particularly to a container opened under more hygienic and pollution free condition. Easy open end can be improved by forming a tear strip on its surface, the tear strip is circumvent by a score line; the tear strip is riveted with a tab by a rivet; further the tear strip is divided into a front and a rear tear strips, a folded line between the front and rear strips can be applied to bend downward the rear tear strip close to the front tear strip; a folded line between the rear tear strip and the lid can be applied to bend the rear tear strip close to the lid; and the front tear strip is riveted adjacent to a nose of the tab by rivet.

Abstract: The invention generally relates to a tab used to open beer/beverage can ends and food can ends. The tab has one or more arcuate strips that are provided on a surface of the tab proximate to a peripheral surface of the tab where the one or more arcuate strips have been formed further into a preselected portion of curled or hemmed portions of the tab. Tooling for the manufacture of the tab is also provided. A method for manufacturing the tab is additionally provided as well.

Abstract: An opening device of plastics material, which is suitable for closing and re-closing of a metal can end, for example. The opening device has two distinct parts: a base plate and a tab, which are joined together by an integral rivet. The opening device is used to close an aperture in the metal panel of a can end by fitting the base plate to the underside of the panel and connecting this to the tab on the top of the panel. A sliding action by pulling or retaining the tab actuates movement of the base plate for opening and reclosing of the closure panel.

Abstract: A can (1) having a spout that can, after opening, be securely resealed and can be opened and closed with an easy operation. The can (1) has a spout (3) that is opened by lifting and pulling a pull-ring (6) fixed on a top wall (2) of a can body (1a) with a rivet (5) to bend a sealing tongue portion (4) toward the inside of the can. Inside the top wall (2) and away from the spout (3), an internal sealing member (7) having a fan shape with its pivot mounted to the rivet and a size capable of sealing the spout (3) is disposed so as to be fixed to the rivet (5). After opening the spout (3), by rotating the pull-ring (6) around the rivet (5), the internal sealing member (7) is also rotated at the same time. As an interlocking mechanism therefor, the rivet (5) is rotatably supported by the top wall (2), and a base end of the pull-ring (6) and the pivot of the internal sealing member (7) are fixed to the rivet (5), respectively.

Abstract: A can lid of a can provided with an easily openable opening means is disclosed wherein the can lid is equipped with a can lid which is fastened by winding tightly on the can main body and the top end opening of the can main body, a score section installed around the territory of the prearranged opening area and a tab for severing the score section. In the can lid, there is formed a protrusion protruding upward from the can lid in front of the can opening during manufacturing of the can lid, in which it is a collapsing protrusion where the protrusion elastically deforms into the can main body by depressing motion of the user and thereby enables forming of a concave section for easy insertion of the user's finger.

Abstract: A stay-on-tab container closure suitable for use on beverage cans and the like, said closure including an center panel with an downwardly displaceable tear panel, which, in one aspect, has a smooth upper surface having no visually perceptible contour features, and which, in another aspect, has low-relief contour features on its upper surface. Closures according to the invention have reduced stresses across the score defining the tear panel, thereby reducing the likelihood of stress-induced fatigue cracking which can lead to score failure when the container closure is joined to a can body and the resulting can is internally pressurized.

Abstract: A device is disclosed for re-closing an opening in a can having a tab opener. The device comprises a mount piece having an overall shape and flexibility that enables it to be pushed through at least one aperture formed in the tab opener thereby securing the device to the tab opener. The device further comprises a plug portion attached to the mount piece and configured to engage and at least partially close an opening in the can.

Abstract: An easy open end for a container includes an end panel having a score defined therein that defines a removable end panel portion. The score is preferably notched to define a bottom edge having a continuous V-shaped recess. A first double fold is defined adjacent to and positioned radially inward from the score that defines beneath the score a first outwardly projecting extending cut protection bead. A second double fold is defined adjacent to and positioned radially outward from the score that defines beneath the score a second inwardly projecting cut protection bead. The end panel is elastically deformed in an area near the score so as to define a concave depression about the score, which provides enhanced cut protection.

Abstract: Protective covering for beverage cans with breakable opening in the lid, with a circular top surface (1) and circumferential lateral surface, that consists of conical strip (3) and cylindrical strip (2) between the top surface (1) and conical strip (3). Conical strip (3) has on its internal circumferential wall unilateral wedge (4) whose front surface (5) is parallel to the top surface (1) and whose working surface (6) is convergent to the conical strip (3). The protective covering can be used to protect the lid and upper wall of a can from dirt.

Abstract: A opening assembly (10) suitable for use on a can for containing carbonated beverages. The assembly (10) comprises a main part (14) with an oval opening (16). A flange (18) is provided around the underside of the opening (16), with a height inversely proportional to the diameter of the opening (16) at any point. A closure member (20) is provided comprising an upper part (14), cylindrical body part (30) which sliding fits through the opening (16), and an engagement member (34) on its underside. In a closed condition the engagement member (34) engages against the tallest part of the flange (18) to sealingly close the assembly (10). The closure member (20) can be rotated until the engagement member (34) is not engageable with the flange (18), and the member (20) can then be removed from the opening (16) to open the assembly (10). The member (20) can be replaced in the opening (16) and rotated to reclose the assembly (10).

Abstract: A cap is provided for covering an opening in a soda can. The cap may include a depression and a peripheral flange connected to the depression. The peripheral flange may at least partially surround the depression. The depression may be adapted to fit into an opening of a soda can created by a pull tab. There may be a gap in the peripheral flange which allows a pull tab to fit over the depression. The cap may include an inner wall which connects the depression to the peripheral flange. A method is provided of pulling a pull tab on a soda can to create an opening in the soda can, and covering the opening with a cap.

Abstract: “DEVICE INSERTED INTO THE SEALED LIDS OF METAL PACKAGING FOR LIQUID PRODUCTS”, comprising a fixing system obtained through a process of crimping to the upper edge of the metal package (1), preferably made of tinplate, characterized by an assembly comprising a plastics membrane (2) and a metal ring (3) stamped to form a flat inner cross section (4), which has a central circular opening (5) with an inner edge turned downward and folded inward (6), and an elevation to form a lower seat (7) which is surrounded by a peripheral rim facing downward and slightly inward (8) to enable crimping together with the aforesaid membrane (2); the peripheral edge (9) which is inserted into the seat (7) for crimping onto the edge of the packaging (1), followed internally by an annular recess (10) into which the flat inner cross section (4) of the metal ring (3) with the inner edge turned down and folded inward (6) is inserted, this being followed internally by a perimetral annular reinforcement (11) and with the lower triangular

Abstract: A lid (30) of plastic material, applied by pressure, having a lateral handle (40), the purpose of the lid being to protect the top of the can (10) for drinks (28) against pollution, includes an opening (23) being made by a tear-off tongue (19), the lid matching substantially with the top of the can. The internal facing of the lid has a protuberance that acts as a stopper (45) and hermetically closes the aperture (28) in the can (10) when opened, thus avoiding accidental spillage of the drink (28) remaining in the can.

Abstract: An end member for a container having a circumferential sidewall, the end member having a peripheral seaming edge adapted to be integrally connected to the sidewall, and having a central panel wall with a means for opening a frangible panel segment of the panel wall is claimed. The end member comprises a deboss panel recessed in the central panel. The deboss panel has first and second spaced apart end portions joined by first and second sidewalls. The first spaced apart end portion has an apex and first and second arcuate portions. A distance between the first and second arcuate portions is defined by a plurality of progressively increasing secant lengths located in spaced relation from the apex. A score groove is located within the deboss panel defining an outer perimeter of the frangible panel segment. The score groove has a first end and a second end joined to the first end by a curvilinear segment. The first end and the second end are separated by a generally linear hinge segment of the central panel wall.

Abstract: A beverage can with a bottom end, a top end, and a side wall extending therebetween. A first weakening score is formed in the top end, and a second weakening score is formed near the bottom end of the can. The beverage can has a first tab selectively displaceable between an initial position wherein the first tab is generally parallel to the can a displaced position wherein the first end pierces the can by causing the first weakening score to fail, thereby forming a first opening. A second tab with features similar to the first tab is positioned near the second weakening score. Specifically, the second tab is selectively displaceable between an initial position wherein the second tab is generally parallel to the can, and a displaced position wherein the first end pierces the can by causing the second weakening score to fail, thereby forming a second opening. Beverage may exit the can from either the first or second opening.

Abstract: An end closure for a container providing a tab with increased resistance to rotation upon a rivet is disclosed. The end closure has a central panel wall having a product side, a public side, a rivet, and a displaceable tear panel in the central panel wall at least substantially defined by a frangible score and a non-frangible hinge segment. A tab is attached to the public side of the central panel wall by the rivet. At least a nose portion of the tab extends over a portion of the tear panel. A lift end of the tab is opposite the tab nose. The tab has a central webbing between the nose and the lift end. The central webbing has an anti-rotation member in communication with the public side of the central panel wall. The anti-rotation member provides a spring force against the central panel wall.

Abstract: A can end includes a peripheral cover hook a chuck wall dependent from the interior of the cover hook, an outwardly concave annular reinforcing bead extending radially inwards from the chuck wall, and a central panel supported by an inner portion of the reinforcing bead, characterized in that, the chuck wall is inclined to an axis perpendicular to the exterior of the central panel at an angle between 20° and 60°, and the concave cross-sectional radius of the reinforcing bead is less than 0.75 mm.