Selectively ventable food package and micro-wave shielding device

• US 4,013,798 A
• Filed: 12/24/1975
• Issued: 03/22/1977
• Est. Priority Date: 11/21/1973
• Status: Expired due to Term

• Current Assignee: Teckton Incorporated
• Original Assignee: Teckton Incorporated
• Inventors: Goltsos, Costas E.
• Primary Examiner(s): Weinstein, Steven L.
• Application Number:
  US05/644,163
• Time in Patent Office: 454 Days
• Field of Search: 426/106, 426/107, 426/113, 426/114, 426/118, 426/120, 426/122, 426/389, 426/392, 426/394, 426/395, 426/396, 426/234, 426/243, 426/410, 426/412, 426/129, 220/44 A, 220/20.5, 220/44 R, 220/20, 220/22, 229/2.5, 229/40, 229/9, 229/19, 229/DIG. 14, 206/45.31, 219/10.55 D, 219/10.55 E
• US Class Current: 426/107
• CPC Class Codes: B65D 2205/00 Venting means
• CPC Class Codes: B65D 2581/344 Geometry or shape factors influencing the microwave heating properties
• CPC Class Codes: B65D 2581/3489 Microwave reflector, i.e. microwave shield B65D2581/3487 takes precedence
• CPC Class Codes: B65D 81/3453 Rigid containers, e.g. trays, bottles, boxes, cups

Abstract

A frozen or refrigerated precooked meal formed from a number of food components is packaged in a compartmented tray which is transparent to radiant energy such as that from microwave or infrared energy sources. Each of the tray compartments is defined by ridges and side walls formed integrally with the tray and the different component foods of the meal are disposed within selected different tray compartments. A radiation transparent film is secured over the tray and is bonded to the upper edge of the tray side wall and ridges to seal each compartment. Selected areas of the seals between the film and portions of the ridges and/or tray side walls are weakened so that they may rupture in response to excessive water vapor pressure build up to enable the water vapor to escape. The sealed food tray may be placed in a specially formed shielding box which controls the quantity of radiation to which each of the food components are exposed within a given time.

Claims

1. A package comprising:

a tray formed from a material transparent to electromagnetic radiation, said tray having a bottom wall, a peripheral upstanding side wall and ridge means extending upwardly from the bottom wall and cooperative with said bottom wall and said peripheral side wall to define a plurality of at least three compartments;

said compartments each containig a food component, at least two, but less than all of said compartments containing food components which will give off water vapor when heat conditioned, said at least two, but less than all of said compartments defining ventable compartments;

a radiation transparent cover extending over said tray and being sealed to the upper edge of said ridge means and said peripheral side wall to isolate said compartments from each other;

means communicating said ventable compartments with each other to permit communication of said water vapor from one of said ventable compartments to the other of said ventable compartments; and

at least one portion of the seal between said cover and said peripheral wall associated with a selected one of said ventable compartments being constructed to be weaker than the other portions of said seal, said one portion of the seal being sufficiently weak as to rupture in response to build up of water vapor pressure in said ventable compartments beyond a predetermined magnitude whereby the water vapor generated in each of said ventable compartments may vent, sequentially, through said ventable compartments and through the ruptured seal in a predetermined direction.

2. A package as defined in claim 1 wherein said means communicating said ventable compartments comprises:

that portion of said ridge means common to said ventable compartments having a depression formed at the upper edge thereof, and being attached to the upper edge of the ridge means, said depression and said cover defining an opening communicating said compartments.

3. A package as defined in claim 1 further comprising:

the upper edge of the peripheral side wall having a rim, the radiation transparent cover being fused to the rim along a seal line which is of a predetermined width;

said seal having a fused region which is of less width than the remaining portions of said seal thereby defining a weakened region.

4. A package as defined in claim 2 wherein said lesser width of said seal between said cover and said rim is defined by means comprising:

a notch formed in said rim said cover being free of any seal to said notched region.

5. A device for use in heat-conditioning a prepared meal by microwave energy comprising:

a tray formed from a material transparent to microwave radiation, said tray having a bottom wall, a peripheral upstanding side wall and ridge means extending upwardly from the bottom wall and cooperative with said bottom wall and said peripheral side wall to define a plurality of at least three compartments;

said compartments each containing a food component, at least two, but less than all of said compartments containing food components which will give off water vapor when heat conditioned said at least two, but less than all of said compartments defining ventable compartments;

a radiation transparent cover extending over said tray and being sealed to the upper edge of said ridge means and said peripheral side wall to isolate said compartments from each other;

means communicating said ventable compartments with each other to permit communication of said water vapor from one of said ventable compartments to the other of said ventable compartments;

at least one portion of the seal between said cover and said peripheral wall associated with one of said ventable compartments being constructed to be weaker than the other portions of said seal, said one portion of the seal being sufficiently weak as to rupture in response to build up of water vapor pressure in said ventable compartments beyond a predetermined magnitude whereby the water vapor generated in each of said ventable compartments may vent, sequentially, through said ventable compartments and through the ruptured seal;

a shielding box formed from a material which is opaque to said microwave energy, said shielding box having an opening therein to removably receive said tray, said shielding box having aperture means formed in the walls thereof to selectively control the degree of exposure of foods within said tray compartments to microwave energy when said tray is in a predetermined orientation within said shielding box;

registration means on said shielding box and said tray to enable insertion of said tray into said box only in said predetermined orientation; and

said weak portion of said seal being located at that portion of said side wall of said tray which is exposed through said opening in said shielding box when said tray is in said predetermined orientation in said box, whereby said ventable compartments may be vented in a direction extending through the opening of the shielding box.

6. Apparatus as defined in claim 5 wherein said registration means comprises:

a guide member secured to said shielding box internally thereof, said guide member being cooperative with a wall of said shielding box to define an opening of predetermined width;

said tray being constructed so that a ridge thereof may receive said guide member when said tray is inserted into said shielding box; and

means forming a depression by the upper surface of said ridge to communicate the tray compartments defined by said ridge, said depression being of a depth which is greater than the dimensions of said opening between said guide member and said wall of said shielding box, said depression being formed on said ridge as to enable full insertion of said tray into said box only in said predetermined attitude.