Patent Application
20070251913
The present invention relates to containers and, more particularly, containers for products which outgas and which employ venting elements.
As is well known, certain products such as coffee tend to outgas and this can cause distortion of the container if the pressure in the container becomes too great, especially in thin walled containers. As a result, some containers use a wall thickness which is increased from that required for a product which does not outgas. This outgassing problem is accentuated with some packaging techniques which utilize the step of purging the ground and roasted coffee to displace oxygen as described in Canadian Patent No. 1,309,992.
Various structures have been proposed to vent the gas evolved from the product such as those shown in Thomas et al Patent Publication US 2004/0096552; Costa et al U.S. Pat. No. 5,370,306; and Jeor U.S. Patent Publication US 2004/0173626.
Although it is desirable to vent the escaping gas, some gas retention is desirable to provide a positive pressure to preclude entry of the ambient air into the container since moisture and gases may be deleterious to the product.
Some containers employ a foil seal to cover the mouth of the container and provide a barrier to ingress of ambient air. This foil seal is removed by the user in order to gain access to the product therein after which there is no longer an effective barrier to protect the contents from moist air, etc. Since there is a need to provide venting for the gas, a valve is provided in the foil seal such as that shown in the Thomas et al Patent Publication.
It is an object of the present invention to provide a novel container assembly for products which offgas during storage and which provide sealing action.
It is also an object to provide such a novel container assembly in which there is a foil seal that shields the product from the atmosphere until the user removes it and a valved vent is provided therein.
Another object is to provide such a container which can be fabricated and assembled easily.
It has now been found that the foregoing and related objects may be readily attained in a container for a product which off-gases comprising a container body with a base wall, sidewall and a large mouth at its upper end bounded by a lip and having an outwardly extending shoulder adjacent the upper end of the sidewall and below the lip. A foil seal extends over the mouth and is adhered to the lip, and it contains a valve therein permitting gases in the container body to exit therethrough. Secured to the container body is a cap having a top wall and a depending skirt with an internal peripheral snap bead located and configured to abut the lower surface of the shoulder on the sidewall of the container body. The bottom surface of the top wall of the cap has a depending flexible ring seal bearing on the lip of the container body. The inside surface of the cap has a multiplicity of channels extending downwardly along the inside surface of the skirt. Gas pressure in the container body will cause the valve in the foil seal to release gas from the interior of the container body into the space in the cap above the foil seal. The pressure of the gas in the space builds until it deflects the ring seal from the lip to allow the gas to flow thereby and outwardly in the channels in the cap and discharge to the atmosphere.
Desirably, the channels extend through the snap bead, and the ring seal is inclined outwardly and downwardly and tapers to a reduced thickness at its lower end. Desirably, foil seal is a metallic foil, and a valve in the foil seal is provided by a multilayer laminate which permits gases to flow outwardly of the container body but restricts air flow therethrough into the container body.
Turning first to
The container 10 has a sidewall 16, a bottom wall (not shown) and a mouth 18 at its upper end bounded by an inturned lip portion 20. Adjacent its upper end, the sidewall 16 has an outwardly oriented shoulder 22 which extends about the circumference thereof and a reduced diameter neck portion 24 therebelow. The foil seal 14 extends over the mouth 18 and is adhered to the lip portion 20, thus sealing the interior chamber 26.
The cap 12 has a top wall generally designated by the numeral 28 and a depending skirt generally designated by the numeral 30, and a snap bead 32 is formed on the inner surface. When the cap 12 is pushed onto the container 10, the skirt 30 is resiliently deflected outwardly to permit the snap bead 32 to pass by the shoulder 22 and seat therebelow. The inclined top and bottom surfaces of the snap bead 32 provide a camming action to facilitate engagement and removal of the cap 12.
Depending from top 28 of the cap is a ring seal 34 which extends about the mouth 18 and bears upon the foil seal 14 and underlying lip portion 20 so as to seal the space around the mouth 18 from the atmosphere. The ring seal 34 is downwardly and radially outwardly oriented and tapers to a reduced cross section at its lower end to permit its deflection radially outwardly. This sealing action will occur with the foil seal 14 still in place and after its removal by the user. A multiplicity of vent channels 36 extend downwardly through the snap bead 32.
Centrally of the mouth 18, the foil seal 14 has a one-way valve 38 which is constructed to allow gas to exit the chamber 26. Generally, such valves are comprised of multiple parts with passages which are opened when the seal is distorted by pressure on one side. Seals with venting valves of various constructions are shown in the following patents: Thomas et al Patent Publication US 2004/0096552; Costa et al U.S. Pat. No. 5,370,306; and Jeor U.S. Patent Publication US 2004/0173626; Pan U.S. Pat. No. 4,210,255; Buchner et al U.S. Pat. No. 4,653,661; Jonkers U.S. Pat. No. 4,828,129; Clougherty et al U.S. Pat. No. 6,662,827 and Miller et al U.S. Pat. No. 6,983,857.
In operation, the product is placed in the chamber 26 of the container 10 and the foil seal 14 is adhered to the lip 20 so as to provide a closed chamber 26. As the amount (and pressure) of the gas released from the product builds up in the chamber 26, the gas acts upon the foil seal to cause it to assume a dome-like orientation seen in
When the user initially opens the container assembly, the foil seal 14 is removed and the ring seal 34 now bears directly on the lip portion 20 to prevent gas from escaping from the container 10 until the pressure reaches a level sufficient to cause deflection of the ring seal 34.
When the ring seal 34 is deflected, there is a short burst of gas released through the snap bead vent channels 36. The ring seal 34 then returns to its sealing position until the gas pressure in the small chamber again reaches a level sufficient to cause deflection and release—a process which is referred to as “burping”.
The configuration of the cap and container can be readily varied from those in the attached drawings so long as the container has a lip about the mouth of the container upon which the ring seal may bear to effect a seal after the foil seal has been removed for access to the contents. It will be appreciated that the ring seal will effectively limit entry of humid or ambient air into the container, and this barrier effect is also provided by superatmospheric pressure of gas from the stored contents in the small chamber.
