Lid for j ars for preserves TEXT OF THE DESCRIPTION

The present invention relates to removable lids for containers, and in particular to a lid for j ars intended for food preservation.

The practice of home preparation of canned food is back in vogue, and this practice is linked to a substantial market for j ars to be used, which must be provided with lids suitable to allow sealing of the vacuum generated during pasteurization.

One of the standard systems for the preparation of canned food at home provides for the use of glass j ars having a thread provided on the side wall of the mouth of the j ar, which is coupled with the thread formed on the side wall of a tin lid, that is made of iron sheet coated with tin, generally by electrolysis, which is provided on the inner face of the closing surface of a gasket capable of making the seal with the trailing edge of the mouth of the j ar. The latter, being made of glass, can be indefinitely reused, whereas the tin lid must necessarily be disposable, as recommended by the producers themselves; this is because of food safety, because the lid would not guarantee the vacuum seal, and because, being made of tin, it cannot be washed in a dishwasher.

Moreover, the gasket is generally made of PVC or

1 similar plastic materials, and this makes the disposal of the lids more complex, increasing the environmental impact of a behavior, that of the production of home preserves, which instead would have all the intentions of being virtuous from the point of view of eco-sustainability .

Document GB2441327A describes a lid for vessels comprising a circular closing surface and a side wall provided with a plurality of cavities on the outer face of said wall corresponding to reliefs protruding from the inner face. But the type of cooperation of the side wall of the lid with the container does not suit the requirements of this application area.

Thus, the purpose of the present invention is to provide a lid for canning j ars which is reusable, which exhibits qualities of solidity and strength on the one hand, and which can be made without particularly complex processing on the other hand, and which allows to make the appropriate seal on the opening to which it is coupled.

Therefore, an obj ect of the present invention is a lid for a preserving j ar, said j ar being provided at the circular mouth with a thread formed on the side wall thereof, and said lid comprising a circular closing plane and a continuous cylindrical side wall, made of stainless steel sheet piece, said side wall being provided with a plurality of recesses on the outer face of said wall, corresponding to protruding

2 reliefs on the inner face, and said reliefs being arranged along a helical path corresponding to the pitch of the threading on the side wall of the mouth of the vessel, and being provided with removable sealing means arranged on the inner surface of the closing plane. The side wall has a height ranging from 18% to 25% of the diameter of the lid plane. Advantageously, such recesses, and corresponding reliefs, are formed by punching the side wall; said reliefs are substantially formed with the height equal to the height of the threading on the side wall of the mouth of the j ar.

In a preferred embodiment, there are provided at least three cavities, and corresponding reliefs, formed on said wall; said reliefs are angularly equidistant from each other, so as to make the coupling with the vessel simple and at the same time stable.

In another variant, on the side wall of said lid is formed a relief proj ecting outwardly, with a corresponding cavity inwardly, formed substantially bell-shaped, and tapered from the trailing edge of the side wall toward the closing plane. This relief allows the insertion of a medium, such as the tip of a knife, as well as the back of another cutlery, so as to facilitate the entry of air into the j ar, at the time of opening for the consumption of the preserve. This relief has a height that can range from 25% to 50% of the height of the side wall, and a maximum width at the base from 70% to 90% of

3 the height of the wall. The relief has a maximum proj ection from the side wall in the range of 4% to 6% of the radius of the closing plane.

The closing plane has a perimeter annular relief, contiguous to the side wall, which protrudes from the closing plane in the range of 5-7% of the side wall height, and a spherical cap relief, which has a maximum protrusion from the closing plane in the range of 5-7% of the side wall height; this configuration promotes elastic loading of the seal.

Further advantages and features of the device according to the present invention will be apparent from the following description of an embodiment of the same rendered, for illustrative and non-limiting purposes, with reference to the accompanying tables of drawings, wherein: figure 1 is a perspective view of an executive form of the lid according to the present invention, illustrated together with the vessel with which it is used; figure 2 is a side elevation view of the lid of figure 1 ; figure 3 is a plan view from above of the lid of figure 1 ; figure 4 is an enlarged view of detail IV of figure 3 ; figure 5 is a section view along the V-V line of figure 3. Figure 1 illustrates in perspective a lid for preserving jars according to the present invention; 1 indicates the lid, while the numeral 10 designates a j ar of the type commonly

4 used for preserving, provided with a circular mouth 1 1 having a cylindrical side wall 12 on which the threading 13 is formed; the vast maj ority of glass preserving j ars have the same type of threading, which is then the one schematically illustrated in the figure. The lid 1 has a closing plane 101 formed of piece with a cylindrical side wall 201 and provided with the perimeter annular relief 121 contiguous to the side wall, and centrally with a spherical cap 101. On the side wall 201 are formed the cavities 21 1 and 221 , to which inside correspond reliefs that below will present the same numbering of the cavities. Between the two cavities 21 1 and 221 is formed the bell-shaped relief 241 , facing the trailing edge of the side wall 201 , and tapered in the opposite direction. On the portion of the side wall 201 proximate to the end plane 101 are formed knurls 251 , while the trailing edge of said wall has a radial flange 261 , facing inward.

Figure 2 shows the lid of figure 1 in lateral elevation; equal parts correspond to equal numerals. The figure shows a third cavity, or relief, indicated by 231 , illustrated in line and point since, as is better shown below, this cavity 231 is located on the non-visible face of lid 1. The three cavities, or reliefs, 21 1 , 221 , and 231 , are located at three different levels on the side wall 201 , and are arranged along the helical path 13', which essentially replicates the helical path of the thread 13 of j ar 10. The slight protrusion from relief

5 121 of cap 1 1 1 can also be noted.

Figure 3 illustrates in plan view the lid according to the invention; equal parts correspond to equal numerals. Highlighted in the figure is the equidistant angular placement of the cavities/reliefs 21 1 , 221 and 231 on the wall 201. In addition, protrusion of the bell-shaped relief 241 from the closing plane 101 of the lid can be seen. Finally, Figure 4 shows detail IV of Figure 3, which allows one to see more clearly the shape and extent of the relief, or cavity, 221 , which is obviously also illustrative of the shape of the other two cavities 21 1 and 231.

Figure 5 shows the sectional view along the V-V line of Figure 3 ; the same numerals correspond to the equal parts. The figure shows the geometry of the closing plane 101 , with at the periphery the protruding relief 121 contiguous to the side wall 201 , and at the center the spherical cap 1 1 1 , also protruding from the closure plane. Also illustrated is the removable gasket 301.

The manufacture and operation of the lid according to the present invention will be apparent from the following. As mentioned above, a main purpose of the present invention is to replace the disposable lids that are currently used for the preparation of homemade preserves with a lid that is long reusable but of acceptable cost. The most suitable material is undoubtedly stainless-steel sheet, having a thickness of

6 between 0.2 and 0.4 mm, so as to be both sufficiently workable and sufficiently strong, and capable of providing the appropriate elastic loading to the seal. The side wall 201 of the lid should have a height that allows cooperation with the entire portion of the side wall 12 of the vessel 10 in which the threading 13 is formed; in particular, the wall has a height of 18% to 25% of the diameter of the lid closing plane.

The closing plane, as shown in the section of Figure 5, is formed such that the relief 121 on one side and the cap 1 1 1 on the other side create the precondition for elastic loading of the seal exerted by the gasket 301. The protrusion of the perimeter relief 121 and the protrusion of the cap 1 1 1 relative to the closing plane 101 are estimated to achieve the elastic loading effect, and are both in the range of 5-7% of the side wall height. The gasket will preferably be made of natural rubber and will still be replaceable and recyclable independently from the lid.

The recesses 211, 221 and 231, i.e., the corresponding reliefs projecting onto the inner face of the side wall 201, are formed by punching, and have a height, and also a width suitable for cooperating with the threading 13 of the vessel 10. The reliefs projecting toward the wall 12 of the mouth 1 1 of vase 10, in the illustrated embodiment have a width at the base substantially double their height. The positioning of the reliefs along the path 13' allows the correct coupling to be established

7 with the threading 13 of vase 10, without the need to form the full threading on the side wall. In addition to simpler manufacturing, the reliefs allow for a quicker and more immediate closing movement by the user than the thread.

The number of cavities that can be formed on the side wall is preferably equal to three. A number greater than three makes the processing too sophisticated, and therefore makes the product less competitive, which is however intended to replace a decidedly cheap item. The equidistant angular distribution of the cavities on the side wall is the one that allows with greater simplicity to realize the coupling with the thread of the j ar

The bell-shaped relief, and its corresponding cavity accessible from the trailing edge of the side wall of the lid, allows the user to release the seal made during pasteurization by inserting a portion of a tableware, and thus makes the use of the lid easier overall. This relief has a height that can range from 25% to 50% of the side wall height, and a maximum width at the base from 70% to 90% of the wall height. The relief has a maximum protrusion from the side wall in the range of 4% to 6% of the radius of the lid closure plane.

The canning j ar lid according to the present invention solves the problems encountered in the state of the art due to its simple and effective structure, which makes it a reusable product for a very large number of cycles.

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