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Title: Nesting insulated hot-or-cold food tray
Claims: We claim: 1. Insulated hot or cold food tray for temporarily storing and transporting food items at temperatures different from ambient temperatures comprising an integral dished tray structure of molded material having a bottom plate surface (10); a surrounding rim (11) formed to incline upwardly with respect to the bottom plate surface; and a flange (12) laterally projecting from the rim generally in a plane parallel to said bottom surface (10); the angle of inclination of the rim being selected such that cotangent .alpha. is at least 1.5 t/D wherein .alpha. equals angle of inclination; t equals wall thickness of the foamed plastic material and D equals depth of the tray structure and corresponding to the distance from the top of the flange (12) to the top of the bottom plate surface (10); said flange (12) being formed with projection and recess means (13, 14; 23, 24) located at regularly distributed spaced intervals around the circumference thereof, the projection means have portions which have a dimension which is greater than the dimension of the recess means (14, 24) at equal spacing from the surrounding rim (11), inversion of one tray over another and engagement of the projection means of one tray in the recess means of the inverted, opposite tray permitting fitting of said flanges together and locking the projection means of one tray through the recess means of the other to engage the flange of the other tray from the face opposite that facing the first tray to provide an insulated storage and transport carrier to transport food items in the chamber formed by the inverted, engaged trays with the flanges of the trays locked together by overlapping engagement of the respective projection means of one tray behind the flanges of the other tray; wherein the projection of the projection and recess means comprises an outwardly tapering tab (13) and inwardly tapering notches (16) formed adjacent both sides of each tab and separating the tab from the surrounding flange area; and the recess means of the projection and recess means comprises an inwardly tapering engagement notch (14), the maximum dimension of the engagement notch lying between the minimum and maximum dimension of the tab, the taper of said tab, and said engagement notches, respectively, being from about 15 mm to 18 mm, and the rim having a width (W) of about 13 mm. 2. Tray according to claim 1, wherein depressed flutes (15) are formed in the flange (12) at spaced locations around the circumference thereof; and the plate surface of the tray is formed with radially extending ridges (R) to elevate the food item above the plate surface, to provide a vent space from beneath the food item and out of the chamber formed by flutes when the trays are inverted over each other to permit venting of steam or condensation, moisture when hot food items are enclosed in a tray pair. 3. Tray according to claim 1 wherein the projection of the projection and recess means comprises an outwardly tapering tab (13) and notches (16) formed adjacent both sides of each tab and separating the tab from the surrounding flange area. 4. Tray according to claim 1 wherein the rim has a width (W) of about 13 mm; the engagement notches taper from about 15 mm to 18 mm, and the tabs taper from about 15 mm to 18 mm. 5. Tray according to claim 2 wherein the projections comprise radially extending ridges (R) formed as corrugations in the bottom plate surface and providing depressed grooves (R') beneath said surface. 6. An enclosed, heat-insulated disposable food carrier comprising two food trays as claimed in claim 1, one tray being inverted over the other to form a heat-insulated chamber between the trays, said trays being interlocked together by engagement of the tabs of one tray into and through the engagement notches of the other tray, and behind the flange portions adjacent the engagement notches of said other tray, and the tabs of the other tray into and through the engagement notches of said one tray and behind the respective flange portions adjacent the engagement notches of said one tray. 7. Insulated hot or cold food tray for temporarily storing and transporting food items at temperatures different from ambient temperatures comprising an integral dished tray structure of molded material having a bottom plate surface (10); a surrounding rim (11) formed to incline upwardly with respect to the bottom plate surface; and a flange (12) laterally projecting from the rim generally in a plane parallel to said bottom surface (10); the angle of inclination of the rim being selected such that cotangent .alpha. is at least 1.5 t/D wherein .alpha. equals angle of inclination; t equals wall thickness of the foamed plastic material and D equals depth of the tray structure and corresponding to the distance from the top of the flange (12) to the top of the bottom plate surface (10); said flange (12) being formed with projection and recess means (13, 14; 23, 24) located at regularly distributed spaced intervals around the circumference thereof, the projection means have portions which have a dimension which is greater than the dimension of the recess means (14, 24) at equal spacing from the surrounding rim (11), inversion of one tray over another and engagement of the projection means of one tray in the recess means of the inverted, opposite tray permitting fitting of said flanges together and locking the projection means of one tray through the recess means of the other to engage the flange of the other tray from the face opposite that facing the first tray to provide an insulated storage and transport carrier to transport food items in the chamber formed by the inverted, engaged trays with the flanges of the trays locked together by overlapping engagement of the respective projection means of one tray behind the flanges of the other tray; wherein the projection means of the projection and recess means comprises buttons (23) formed on the flange (22) and projecting from the major plan thereof; and the recess means comprises notches (24) formed in the periphery of the rim and shaped to at least in part surround the buttons (23); the surface (23') of the button (23) facing the center of the tray being slightly closer to the center of the tray than the surface (24') of the notch closest to the center of the tray the thickness of the material of the button (23) adjacent said surface (23') facing the center of the tray is reduced to permit indentation or undercutting of the button when the button (23) of one tray is engaged in the notch (24) of another tray inverted thereover to result in overlap, or bulging over of the button (23) beneath the flange formed with the notch (24). 8. Tray according to claim 7, wherein depressed flutes (15) are formed in the flange (12) at spaced locations around the circumference thereof; and the plate surface of the tray is formed with radially extending ridges (R) to elevate the food item above the plate surface, to provide a vent space from beneath the food item and out of the chamber formed by flutes when the trays are inverted over each other to permit venting of steam or condensation, moisture when hot food items are enclosed in a tray pair. 9. An enclosed, heat insulated disposable food carrier comprising two food trays as claimed in claim 7, one tray being inverted over the other to form a heat insulating chamber between the trays, said trays being interlocked together by engagement of the buttons of one tray into and through the notched of the other tray, and behind the flange portions adjacent the notches of said other tray by undercutting of the material of reduced wall thickness of the button by said adjacent flange portions of said other tray, and the buttons of the other tray into the notches of said one tray and behind the respective flange portions adjacent the notches of said one tray, by undercutting the buttons in the region of reduced thickness of material by said adjacent flange portion of said one tray. Other info: Inventors: Holden, Jr., Morell J. (Canandaigua, NY, US) LeBoutillier, Frank (Canandaigua, NY, US) Application Number: 481095 Filing Date: 1974-06-20 Publication_date: 1976-02-17 Assignee: Mobil Oil Corporation (New York, NY) Primary Class(es): 229/406 229/103.11, D7/605, D9/426 Other Classes: US Patent Ref:
Other Refs:
Primary Examiner: Moorhead, Davis T. Assistant Examiner: Attorney: Huggett; Charles A. |
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