Jar cap with vacuum relief closure

Abstract

A jar cap is formed with an orifice through its flat top surface and an adhesive coated closure tab is placed over the orifice. The closure tab has a non-adhesive portion for being grasped. The jar is closed with the cap and vacuum sealed. When the cap is to be removed, the non-adhesive portion of the closure tab is grasped and the closure tab is pulled off the orifice, allowing ambient air to enter the jar and relieve the vacuum so as to make the removal of the cap easier.

Description

FIELD OF THE INVENTION

The present invention relates to the field of container closures and more particularly to closures for vacuum-sealed jars.

BACKGROUND OF THE INVENTION

Many foods are sold in jars that are sealed before the cooked contents cool to create an internal vacuum condition to securely hold the jar cap in place and effectively protect the contents from becoming contaminated. Vacuum sealing pertains both to jar caps with full threading requiring a complete rotation or more to be removed and quick-release jar caps requiring less than a quarter turn to be removed. A problem exists in that removing the vacuum-sealed jar caps requires the application of significantly more torque, in the range of 33% to 100% more torque, than needed to remove the same caps without a vacuum seal. Because of this greater torque requirement, many people have difficulty removing a cap from a vacuum-sealed jar. When the person is older, or has less hand strength than average, removing a vacuum-sealed cap from a jar becomes a major challenge.

Over the years, different devices have been developed and sold to attempt to overcome the problem of removing the vacuum-sealed jar cap. Some of these devices serve as a tool to increase the gripping force and torque the person can apply to the cap through leverage. Some are simply an elastomeric frictional pad to increase the amount of grip the person applies with the same force. Some are electrically driven clamping chuck devices to unscrew jar caps. In all cases, the vacuum has to be overcome, and traditionally a greater torque has been the available means to do so. The present invention overcomes the problem through a novel and simple approach that eliminates the need for use of a tool.

SUMMARY OF THE INVENTION

The present invention jar cap with vacuum relief closure provides a means of relieving a vacuum in a closed jar without using a tool. Once the vacuum is relieved, the amount of torque needed to open the jar cap is significantly reduced. The invention includes a jar cap with an orifice formed through its top surface and an adhesive coated closure tab removably affixed to the cap so as to cover the orifice. When the jar is vacuum-sealed, the closure tab is held in place both by the adhesive and the power of the vacuum. When the closure tab is removed from the cap, the orifice is exposed and ambient air enters the jar to relieve the vacuum. The jar can then be opened more easily.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is best understood in conjunction with the accompanying drawing figures in which like elements are identified by similar reference numerals and wherein:

FIG. 1 is a front perspective view of a closed jar with the vacuum relief closure cap of the invention, the jar shown in dashed lines.

FIG. 2 is a front perspective view of the closed jar of FIG. 1 with the vacuum relief closure tab removed.

FIG. 3 is a bottom plan view of the vacuum relief closure tab of the invention showing an adhesive pattern thereon.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to FIG. 1, a vacuum sealed jar 10 is shown in dashed lines with a cap 12 in place on jar 10. Cap 12 may be of the type requiring one or more complete revolutions to be removed from jar 10 or a quick-release type requiring less than a quarter turn to be removed. For either type cap, sealing under vacuum has been done and cap removal, prior to the present invention, would require the application of considerable torque. The invention recognizes that whereas the created vacuum protects the contents of the jar from degradation, the vacuum holds the jar cap securely requiring considerable strength to remove the cap from the jar. To reduce the needed torque, the vacuum may be relieved by forming a hole through the jar cap, the hole remaining sealed during storage. The invention described below provides one embodiment for covering and uncovering a hole formed through a jar cap. After the vacuum has been removed, the hole cover may be reapplied over the hole to keep the jar contents from becoming contaminated.

Cap 12 is formed with an orifice 16 through its flat top surface. Orifice 16 is of any convenient size, for example 1.0 mm (0.040 inches) in diameter. A closure tab 18 is positioned on cap 12 over orifice 16 to prevent ambient air from entering jar 10 and equalizing pressure. Closure tab 18 is formed in a convenient shape from a sheet of flexible material, for example plastic sheet, preferably a non-elastic plastic sheet, and most preferably metallic coated Mylar® sheet, with an adhesive coated on the surface in contact with cap 12. Closure tab 18 is held in position over orifice 16 both with its adhesive and the suction of the vacuum within jar 10.

Referring now to FIG. 2, cap 12 remains in place on jar 10 and closure tab 18 has been pulled upwardly, generally in the direction indicated by arrow X to expose orifice 16. Once closure tab 18 is removed from the position over orifice 16, ambient air enters the headspace above the product in jar 10 to relieve a vacuum therein and allow cap 12 to be removed from jar 10 with the application of substantially less torque than would otherwise have been required.

Referring now to FIG. 3, closure tab 18 is shown apart from cap 12 with the lower surface of closure tab 18 showing. Closure tab 18 is illustrated as being formed in a teardrop shape. The teardrop shape of closure tab 18 provides a large, substantially round adhesive area A for the application of an adhesive and an extended lift portion 20 to be grasped for removal of closure tab 18 from cap 12. Closure tab 18 is formed and positioned such that adhesive area A is substantially centered about orifice 16 (FIG. 2) to leave an equal and maximum area of adhesive A around orifice 16 to the edge of closure tab 18 in all directions. Other shapes may be used, for example rectangular, within the scope of the invention. In the preferred embodiment of the invention, adhesive area A is coated with an adhesive that is aggressive and approved for use with food. Lift portion 20 is not coated with adhesive to allow a user to grasp lift portion 20 and lift closure tab 18 from jar cap 12 (FIGS. 1 & 2) to relieve the vacuum within jar 10.

While the description above discloses preferred embodiments of the present invention, it is contemplated that numerous variations and modifications of the invention are possible and are considered to be within the scope of the claims that follow.

Claims

1. A jar cap with vacuum relief closure, comprising:

a. a threaded jar cap having an orifice formed therethrough; and

b. a closure tab positioned on the cap to seal the orifice.

2. The jar cap described in claim 1, wherein the closure tab is coated on a surface thereof with an adhesive in a first portion and remains uncoated in a second portion,

3. The jar cap described in claim 1, wherein the closure tab is formed of a flexible sheet material.

4. The jar cap described in claim 2, wherein the adhesive is an aggressive, food grade adhesive.

5. The jar cap described in claim 1, wherein the closure tab is teardrop shaped.

6. A method for relieving a vacuum in a vacuum-sealed jar, comprising the steps of:

a. closing a jar with a jar cap having an orifice formed therethrough;

b. covering the orifice;

c. vacuum sealing the jar;

d. uncovering the orifice to allow ambient air to enter the jar and equalize pressure; and

e. removing the jar cap.

7. The method described in claim 6, wherein the step of covering the orifice comprises applying a closure tab to the jar cap in a position to cover the orifice.

8. The method described in claim 7, wherein the closure tab is coated on one surface with an adhesive and the adhesive-coated surface is placed in contact with the jar cap.

9. The method described in claim 7, wherein the step of uncovering the orifice comprises removing the closure tab from over the orifice to allow ambient air to enter the jar and equalize the pressure.

10. The method described in claim 8, further comprising the step of reapplying the adhesive coated closure tab to cover the orifice after the pressure has been equalized.