Patent Application
20160009464
The present invention is in the field of removable lids, specifically removable lids on vacuum sealed jars, and which are screwed on and off. More specifically this invention relates to a lid which has an apparatus to automatically release the vacuum which is applied during manufacture, thus making the jar easier to open.
Typically these types of lids are metallic and circular with threads inside the lid to fit corresponding threads on a the jar to be sealed. During production the container is usually vacuum sealed to improve the seal between the lid and the body. These vacuum sealed lids are often difficult to open, as the user must initially overcome the frictional force which is enhanced by the force of the vacuum.
There have been attempts at a design to overcome this issue. European patent application EP2535290 discloses a metal lid with a vacuum release button. This ‘button’ is manually pushed by the consumer to break through the seal. However, breaking through the seal in this manner requires the consumer to break an opening into the lid. Thus, after the seal is broken, there is a permanent slit in the lid, making future use of the jar (for instance if it is jam, that would be kept for some time after opening) subject to the presence of essentially a permanent crack in the lid. Further, this design requires purposeful scoring or weakening of the surface in a specific location. Therefore, if unintended pressure were put on this location, for instance in stacking items on grocery shelves, there is the possibility of inadvertently breaking this seal.
U.S. Pat. No. 5,439,724 to Rojek also shows a lid designed to overcome the difficulty in opening a vacuum seal. In Rojek, the lid is manufactured with a specific depression in the middle, and a through hole. Then a resin-like material is formed to fit in this depression, and through the through-hole such that it is adhered to the internal sealant. To open the lid, the resin like ‘plug’ is removed, thus opening a hole in the sealant, and releasing the vacuum. However, per the disclosure, after the removal of this plug, “the lid will remain free, due to elimination of vacuum, the only element which retains the metal lid in place.” Thus it would not be adequate to store unused portions in the jar after opening.
A removeable lid is desired which would allow for reduced force opening, while still allowing for storing of unused portion in the jar, and which would allow the design of the lid itself to remain almost unchanged. This can be accomplished by having an integral part of the lid which automatically releases the vacuum.
This invention is easily adapted to a standard lid design with the added step of punching holes in the metal lid blank during manufacture. A snap-on ring 20, which snaps on to the metal lid is then added.
Various aspects of the invention are presented in
The lid 10 is a standard metal lid blank with one or more through holes 11 punched in during manufacture. According to an aspect of the invention, the through holes 11 are holes, wherein the holes are an arc of a circle, such that the centerpoint of such circle is the same as the centerpoint 12 of the lid 10.
The vacuum release apparatus is a lid cap 20 which snaps onto the top of the lid 10, having one or more protrusions 21, wherein the protrusions 21 align with the through holes 11. The lid cap 20 is rotatable relative to the lid 10, and the through holes 11 are larger than the protrusions 21, such that when the cap 20 is rotated relative to the lid 10, it can rotate for the distance of the hole. During manufacture, the lid cap 20 would be placed on the lid 10 such that the protrusions 21 are through the holes 11, and are seated at the furthest clockwise position of the through hole 11 when looking from the top, allowing for clearance for the sealant to cover the cut edges 13 of the hole. The underside of the lid would then be coated with a sealant. The protrusions 21 are sufficient such that when the cap 20 is rotated relative to the lid 10, the movement of the protrusions 21 in the through holes 11 is sufficient to tear the sealant coating 30, thus breaking the vacuum seal. When the protrusions 21 reach the end of the hole 11, the lid cap 20 will no longer rotate counterclockwise relative to the lid 10, and continued counter-clockwise motion would thus open the lid without the added resistance of the vacuum seal. These 2 positions are shown in
In a preferred embodiment, the lid cap 20 is in the form of a ring sized slightly bigger than the lid diameter 14, and having sides which are slightly deeper than the depth of the lid. The ring has a top flange 26 which is sized such that the flange covers the through holes 11. The lid cap 20 may snap over the lid 10 by having a bottom flange 22 with a diameter 23 slightly less than the lid diameter 14 on the bottom side of the ring, and being made of a material with enough flexibility that the ring sides can expand to get the ring around the lid before the bottom flange snaps into place on the underside of the lid. Slits 24 could also be cut on the side of the ring to give added flexibility to enable the ring to snap on over the lid. In a preferred embodiment, the lid cap is made of plastic.
According to an aspect of the invention, there are three thru-holes, and three protrusions. There may be more or less. In a preferred embodiment, the protrusions are oblong. The protrusions may also be circular, or have a sharp edge, but may be any shape which would break the vacuum sealant coating. The through holes are larger then the protrusion, to allow movement of the protrusions relative to the lid.
