Abstract:
A hermetically sealable container with internal partial vacuum making facilities, comprising a base body with which a lid is hermetically associable, the lid having, at least in its peripheral region, an elastically flexible portion that has a groove arranged peripherally and open toward the edge of the base body. On the edge of the base body, at least one through hole is provided, arranged at a distance from the free border of the edge of the base body that is shorter than the depth of the groove.

Description:
BACKGROUND OF THE INVENTION 
   The present invention relates to a hermetically sealable container with means for producing an internal partial vacuum. 
   As is known, containers generally used to preserve foodstuffs are already commercially available which can be closed hermetically and have a lid, usually made of flexible material, which is flexible so that it is possible to expel a certain amount of air during closure, so that when the lid is released a partial vacuum is produced inside the container. 
   In the prior art devices, the air expulsion step must be performed with the lid on, with the lid groove for forming a seal with the edge of the base body having to remain, at least in some portions, spaced from the edge of the base body. Therefore during the final step of the lid closure a certain amount of previously expelled air often reenters the container, consequently reducing is the partial vacuum. 
   Another problem noted in the containers of the prior art is that a certain skill is required from the users in order to achieve correct closure. 
   SUMMARY OF THE INVENTION 
   The aim of the present invention is to solve the above described drawbacks by providing a hermetically sealable container with means for producing an internal partial vacuum, which allows to provide a high partial vacuum by utilizing a new and innovative principle that prevents air from reentering the container even partially during the final step of the closure of the lid. 
   Within this aim, an object of the present invention is to provide a hermetically sealable container that can be closed simply and rapidly without requiring particular skill on the part of the user. 
   Another object of the invention is to provide a hermetically sealable container that thanks to its particular constructive characteristics is capable of giving the greatest assurances of reliability and safety in use and is also competitive from a merely economical standpoint. 
   This aim and these and other objects that will become better apparent hereinafter are achieved by a hermetically sealable container with means for producing an internal partial vacuum, according to the invention, comprising a base body with which a lid is hermetically associable, such lid having, at least in its peripheral region, an elastically flexible portion that has a groove that is arranged peripherally and is open toward the edge of said base body, characterized in that it comprises, on said edge of the base body, at least one through hole arranged at a distance from the free border of said edge of the base body that is shorter than the depth of said groove. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Further characteristics and advantages of the present invention will become better apparent from the following detailed description of a preferred but not exclusive embodiment of a hermetically sealable container with means for producing an internal partial vacuum, illustrated by way of non-limitative example in the accompanying drawings, wherein: 
       FIG. 1  is a schematic transverse sectional view of a container according to the invention; 
       FIG. 2  is a schematic view of multiple mutually stacked base bodies; 
       FIG. 3  is an enlarged-scale sectional view of the detail of the step in which pressure is applied to the lid in order to place it in partial vacuum; 
       FIG. 4  is a sectional view of the detail of the hermetically closed container. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   With reference to the figures, the hermetically sealable container with means for producing an internal partial vacuum, according to the invention, generally designated by the reference numeral  1 , comprises a base body  2  to which a lid, designated by the reference numeral  3 , can be applied hermetically. 
   The base body  2  preferably but not necessarily has walls with a lateral surface  4  which are inclined outwardly and have a substantially sinusoidal profile. 
   Satin-finished bands and clear bands can be provided alternately on the walls in order to better view the contents of the container. 
   The sinusoidal shape of the walls, together with their inclination, allows easy stacking of multiple containers, as shown schematically in  FIG. 2 . 
   Proximate to the upper part, the container has an edge  10  at which there is an external horizontal peripheral rim  5 , that runs along the entire peripheral region of the base body  2 . 
   The lid  3  is preferably but not necessarily provided with a central portion  20  that is substantially rigid and is delimited by a tab  21 , which protrudes along the circumference of the lid and extends radially up to, and so that it does not protrude with respect to, the region delimited by the edge  10  of the base body, both internally and externally. 
   A flexible portion  22  is applied at the tab  21 , is arranged peripherally and defines a peripheral groove  23  that is open toward the edge  10  of the base body. 
   The groove  23  is delimited by an internal or inner lip  25  and by an external or outer lip  26 , which ends with a circumferential wing  27  which, when the container is in the closed position, is designed to be arranged in abutment against the rim  5  formed by the base body  2 . 
   The particular characteristic of the invention is that at the edge  10  there is at least one, but preferably a plurality of through holes  30  designed to allow the outward release of the air contained in the container by applying to the lid a pressure that produces expulsion. 
   To close the container hermetically by means of the lid, it is sufficient to apply pressure in the direction of the arrow A 1  of  FIG. 3  and simultaneously pull upward with a movement B 1 , so as to arrange the lid slightly at an angle on the base body and so that the groove engages the free border of the edge  10  of the base body. 
   In this condition, the lid is applied in practice hermetically with respect to the edge, but leaves free the hole  30 , since the inner and outer lips  25  and  26  are spaced from the holes or in any case from at least one hole formed in the edge  10 . 
   By applying pressure, the air is pushed so as to exit from the hole or holes that remain open. 
   When force is applied along the direction B 2 , the lid is closed completely and the lips  25  and  26  cover the through holes  30 . 
   It should be observed that the flexing of the outer lip  26  produced by applying the force in the directions A 1  and B 1  preferably forms an angle, of the wall of the outer lip  26  that faces the groove  23  with respect to a vertical direction of the resting surface of the container or lid, which can be estimated at approximately 7–9°. 
   With this operation, the container is closed hermetically and the air inside it is in partial vacuum. 
   The presence of the holes  30  provides facilities or means that allow to expel more air than in conventional containers of equal shape and size, since in known containers in order to allow the excess air to flow out it is necessary to leave an opening between the upper edge of the container and the lid, and therefore air may reenter while the lid is being closed. 
   Moreover, with the described arrangement a larger amount of air is expelled; this amount can be estimated roughly as approximately half of the product of the surface and the distance h between the free border of the edge  10  and the upper portion of the holes  30 . 
   With the described arrangement a higher partial vacuum and accordingly a better hermetic closure is therefore obtained. 
   With the above described arrangement, and particularly by using a lid that has a rigid central portion, it is possible to introduce directly the container with the lid, from a refrigerator or freezer, into a microwave oven without running the risk of expulsion or explosion, since any pressure on the inner surface of the lid generated by the steam produced during heating causes the tab  21  to oscillate, consequently divaricating inward the inner lip  25  and allowing to vent the steam through the holes, and therefore the cover is not subjected to expulsion pressure. 
   It is thus evident from the above description that the invention achieves the intended aim and objects and in particular the fact is stressed that the adoption of a constructively simple solution such as the provision of holes on the edge allows to already couple the lid hermetically to the base body yet still be able to continue expelling the air. 
   Moreover, the elastic lips that form the groove in which the edge of the base body is accommodated are able to apply a perfect hermetic closure. 
   The invention thus conceived is susceptible of numerous modifications and variations, all of which are within the scope of the appended claims. 
   All the details may further be replaced with other technically equivalent elements. 
   In practice, the materials used, so long as they are compatible with the specific use, as well as the contingent shapes and dimensions, may be any according to requirements. 
   The disclosures in Italian Patent Application No. MI2001A001609 from which this application claims priority are incorporated herein by reference.