US 3362834 A
Description (OCR text may contain errors)
Jan. 9, 1968 c. F. KAYE 3,362,834
DEFROST INDICATOR FOR FROZEN FOOD PACKAGES Filed May 11. 1965 fimzim xmwg 3 Q A r g ,m
United States Patent 3,362,834 DEFRGST INDICATOR FOR FROZEN FOOD PACKAGES Charles F. Kaye, 51 Edsell Road, Littleton, Mass. 01460 Filed May 11, 1965, Ser. No. 454,927 3 Claims. (Cl. 99192) This invention relates to a defrost indicator for frozen food packages, and pertains more particularly to improvements in an indicating device adapted to be inserted through a Wall of a frozen food package and to display a colored signal in the event the contents of the package have become defrosted during transportation, storage, or when displayed in the cabinet of a food store or market.
I am aware that various types of defrost indicators have heretofore been designed for this purpose, but, so far as I am aware, none of them has proved commercially successful.
It is accordingly the principal purpose of this invention to provide a practical and commercially usable, safe and eflicient defrost indicator which may 'be easily applied to frozen food packages of various forms, which will display a clearly visible signal in the event the contained foods become defrosted, whether or not the package is refrozen, and which will react to temperature elevation within the package rather than to changes in temperature outside the package.
The novel features and advantages of the improved indicator will become apparent from the following description of the recommended embodiment of the invention shown on the accompanying drawings; but it will be understood that the structural details of the device herein illustrated and described may be varied to suit particular purposes or conditions without departing from the essence of the invention as set forth in the appended claims.
In the drawings,
FIG. 1 is a perspective view of a representative frozen food package to which the improved defrost indicator has been applied;
FIG. 2 is a sectional view of the indicator in a first stage or condition;
FIG. 3 is a view similar to FIG. 2 showing a second condition or stage of the indicator, prior to insertion into the food package;
FIG. 4 is another view similar to FIG. 3, showing a third stage of the indicator, as inserted into the frozen food package, prior to any defrosting of the contents; and
FIG. 5 is a view similar to FIG. 4 showing a fourth condition or stage of the indicator after defrosting of the contents of the package has occurred.
In the embodiment chosen for the purpose of illustration, the defrost indicator comprises a tube 11 of Lucite or other non-toxic, plastic material, preferably having an annular flange 12 at one end. In use, the tube 11 is inserted into a frozen package 13, through a suitable opening formed in a wall of the package, with the flange 12 disposed on the surface of said wall and suitably secured thereon, adhesively or otherwise.
The tube 11 has an axial bore 14 of relatively small diameter, and end recesses or chambers 15 and 16 of relatively large diameter. A diaphragm 17, of rubber or odrer expandable and resilient material is located in the bottom of chamber 15 and is preferably secured in place by a washer or grommet 18 which is adhesively attached to the wall of the chamber and which bears upon the 3,362,834 Patented Jan. 9, 1968 peripheral margin of the diaphragm or resilient membrane 17 (FIG. 2).
In order to condition the indicator for its intended purpose, the diaphragm is firstdrawn outwardly to a bulblike position 17 (FIG. 3) by a vacuum or suction pump (not shown) suitably applied to the mouth of chamber 15; the bulb 17 and the bore 14 of the tube 11 are then filled with water 19 containing a non-toxic food coloring, such as red, from the open end of the tube at the chamber 16; and a pressure seal, such as the plastic disc 20, is placed over the entrance of the bore at the bottom of the chamber 16, and secured in place by adhesive or otherwise. The colored liquid is preferably injected into the bore 14 while the tube 11 is supported with its bulb 17' downmost. The bulb should be filled with the liquid, but the bore need not be completely filled. After such sealing, the vacuum or suction appliance may then be detached from the mouth of chamber 15.
The indicator is thus converted to its second stage or condition, as shown in FIG. 3, and may be inserted into the food package in that condition, or may be frozen before such insertion. In either event, the liquid in the bulb and bore is frozen solid, as at 19 in FIG. 4, so that the frozen liquid provides a source of restrained potential energy which is released upon subsequent melting.
Next, either before or after the frozen indicator has been inserted into the frozen food package, an opening 21 is pierced in the center of the sealing disc 20, and a second disc 22, of blotting paper or other absorbent material, of white or neutral color, is placed upon the disc 29, Within chamber 16, and suitably secured thereto, over the opening 21. Otherwise, the absorbent disc may be held in place by a larger disc 23, of transparent plastic or the like, suitably applied to the outer end of the tube 11 and its flange 12 (FIG. 4). The indicator, in this third condition or stage, is ready for insertion into the frozen food package 13, if not previously inserted, and to display a visible signal, if and when the contents of the package become defrosted.
In that event, the frozen colored water 19' in the tube bore and in the expanded bulb 17 will melt, and the resilient diaphragm 17 will deflect to its initial position (FIG. 5), thereby helping to convey the water in the bore through the opening 21 in sealing disc 20, to saturate the absorbent disc 22 which will display the signal color red, or other selected color, through the transparent cover disc 23.
The visible colored signal will indicate to the observer of the package that the contents of the package have been defrosted, and possibly spoiled, even though the package should be refrozen. The absence of such a color signal will ensure the prospective purchaser, and the shippers and store personnel, that the package has been maintained in frozen condition and is suitable for sale and consumption.
1. A defrost indicator for insertion into frozen food packages, comprising a tube having a bore of relatively small diameter, and having recessed chambers of relatively large diameter at its opposite ends; a resilient diaphragm secured in the bottom of one of said chambers and expanded into bulb form within said chamber; a frozen colored liquid disposed in said bore and said expanded diaphragm ibulb; a sealing disc secured over the mouth of the bore in the other chamber; said sealing disc having an aperture communicating with the bore, while the liquid is frozen; and a liquid absorbent disc secured to the outer 3 surface of the sealing disc over its aperture, and adapted to absorb the colored liquid when the liquid is melted and conveyed through said aperture upon the deflection of the resilient diaphragm thereby indicating that thawing of the frozen food to which the indicator is associated has occurred.
2. A defrost indicator as described in claim 1, said diaphragm being secured in said chamber by a washer fastened to the Wall of said chamber and bearing upon the peripheral margin of the diaphragm.
3. A defrost indicator as described in claim 1, said tube having an annular flange at the end adjacent to said disc-containing chamber, and a transparent cover disc applied to said end of the tube and to its said flange.
References Cited UNITED STATES PATENTS 2,788,282 4/ 1957 Hammond 99192 2,951,764 9/1960 Chase 99192 3,055,759 9/1962 Busby et a1. 99192 10 RAYMOND N. JONES, Primary Examiner.
S. DAVIS, Assistant Examiner.