Flexible warming structure
First Claim
1. A transparent flexible warming structure comprising:
- a first flexible transparent plastic sheet having a pair of side edges;
an electrically conductive transparent heater layer over substantially all of one side of the sheet;
a second flexible transparent plastic sheet bonded to the heater layer over substantially all of its area except a portion of a strip along each of the pair of side edges; and
a high conductivity flexible strip electrically and mechanically bonded to the heater layer along each of the pair of side edges;
said plastic sheets being selected from synthetic resins that are substantially transparent in the visible spectrum and substantially opaque in bulk in the infrared spectrum, have a heat deformation of less than about 1 percent in any direction at about 150* F, have an elastic modulus in the range of about 1.8 X 105 to 4.5 X 105 psi, and are selected from the group consisting of polycarbonate resin, polyimide resin, fluorinated ethylene-propylene resin, polyamide resin, polyester resin, polyacrylic resin and cellulose triacetate resin, at least one of said sheets having a sufficiently low vapor pressure to be vacuum metallizable, the total thickness of the flexible warming structure being up to abouT 30 mils so as to be readily bent by hand.
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Accused Products
Abstract
A transparent flexible warming structure particularly useful as a medical accessory such as an incubator or other individual patient warming structure is described herein. The structure comprises a pair of flexible transparent plastic sheets having an electrically conductive transparent heater layer over substantially the entire extent thereof sandwiched between the plastic sheets. A metal strip is electrically and mechanically connected to the heater layer along side edges so that passage of an electric current therebetween causes heating over the entire transparent flexible structure. In some embodiments, the transparent sheet structure is placed in a rigid frame substantially the same size as the periphery of the heater. In other embodiments, the flexible sheet is arched between a pair of rigid rails which provide mechanical and electrical contacts.
61 Citations
21 Claims
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1. A transparent flexible warming structure comprising:
- a first flexible transparent plastic sheet having a pair of side edges;
an electrically conductive transparent heater layer over substantially all of one side of the sheet;
a second flexible transparent plastic sheet bonded to the heater layer over substantially all of its area except a portion of a strip along each of the pair of side edges; and
a high conductivity flexible strip electrically and mechanically bonded to the heater layer along each of the pair of side edges;
said plastic sheets being selected from synthetic resins that are substantially transparent in the visible spectrum and substantially opaque in bulk in the infrared spectrum, have a heat deformation of less than about 1 percent in any direction at about 150* F, have an elastic modulus in the range of about 1.8 X 105 to 4.5 X 105 psi, and are selected from the group consisting of polycarbonate resin, polyimide resin, fluorinated ethylene-propylene resin, polyamide resin, polyester resin, polyacrylic resin and cellulose triacetate resin, at least one of said sheets having a sufficiently low vapor pressure to be vacuum metallizable, the total thickness of the flexible warming structure being up to abouT 30 mils so as to be readily bent by hand.
- a first flexible transparent plastic sheet having a pair of side edges;
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2. A transparent flexible warming structure as defined in claim 1 wherein one sheet is relatively thicker than the other sheet.
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3. A transparent flexible warming structure as defined in claim 1 wherein the plastic sheets are each selected from the group consisting of polyethylene terephthalate and polyamide resin.
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4. A transparent flexible warming structure as defined in claim 1 wherein the plastic sheets are polyethylene terephthalate and wherein one sheet is in the order of about 0.005 inch thick and the other sheet is in the range of from about 0.007 to 0.01 inch thick.
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5. A transparent flexible warming structure as defined in claim 1 wherein one of said plastic sheets has a relatively higher stiffness and the other plastic sheet has a relatively lower stiffness.
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6. A transparent flexible warming structure as defined in claim 1 wherein both sheets comprise polyethylene terephthalate of substantially equal thickness.
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7. A transparent flexible warming structure as defined in claim 1 wherein one of said plastic sheets has a relatively higher infrared emittance and the other plastic sheet has a relatively lower infrared emittance.
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8. A transparent flexible warming structure as defined in claim 1 wherein the pair of side edges are substantially equally spaced apart and wherein the heater layer is relatively wider at one portion between the side edges and relatively narrower in another portion between the side edges.
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9. A transparent warming structure as defined in claim 8 wherein one of the high conductivity strips is longer than the other of the high conductivity strips.
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10. A transparent flexible warming structure as defined in claim 1 wherein the first sheet comprises polyethylene terephthalate in the order of about 0.005 inch thick and the second sheet comprises polyethylene terephthalate in the range of from about 0.007 to 0.01 inch thick.
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11. A transparent flexible warming structure comprising:
- a first flexible transparent polyethylene terephthalate sheet having a pair of side edges;
an electrically conductive transparent heater layer over substantially all of one side of the sheet;
a second flexible transparent polyethylene terephthalate sheet bonded to the heater layer over substantially all of its area; and
a high conductivity strip electrically and mechanically bonded to the heater layer along each of a pair of its side edges;
said polyethylene terephthalate sheets being substantially transparent in the visible spectrum and substantially opaque in bulk in the infrared spectrum, have a heat deformation of less than about 1 percent in any direction of about 150*F, at least one of said sheets having a sufficiently low vapor pressure to be vacuum metallizable, one of the sheets being in the order of about 0.005 inch thick and the other sheet being in the range of from about 0.007 to 0.01 inch thick, one of the sheets having a relatively higher stiffness and the other sheet having a relatively lower stiffness, and one of the sheets having a relatively higher infrared emittance and the other sheet has a relatively lower infrared emittance.
- a first flexible transparent polyethylene terephthalate sheet having a pair of side edges;
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12. A TRANSPARENT FLEXIBLE WARMING STRUCTURE COMPRISING:
- A FIRST FLEXIBLE TRANSPARENT PLASTIC SHEET HAVING A PAIR OF SIDE EDGES, AN ELECTRICALLY CONDUCTIVE TRANSPARENT HEATER LAYER OVER SUBSTANTIALLY ALL OF ONE SIDE OF THE SHEET, A SECOND FLEXIBLE TRANSPARENT PLASTIC SHEET BONDED TO THE HEATER LAYER OVER SUBSTANTIALLY ALL OF ITS AREA, AND A HIGH CONDUCTIVITY FLEXIBLE STRIP ELECTRICALLY AND MECHANICALLY BONDED TO THE HEATER LAYER ALONG EACH OF A PAIR OF ITS SIDE EDGES, SAID PLASTIC SHEETS BEING SELECTED FROM SYNTHETIC RESINS THAT ARE SUBSTANTIALLY TRANSPARENT IN THE VISIBLE SPECTRUM AND SUBSTANTIALLY OPAQUE IN BULK IN THE INFRARED SPECTRUM, HAVE A HEAT DEFORMATION OF LESS THAN ABOUT 1 PERCENT IN ANY DIRECTION AT ABOUT 150*F, HAVE AN ELASTIC MODULUS IN
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13. A transparent flexible warming structure as defined in claim 12 wherein one sheet is relatively thicker than the other sheet.
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14. A transparent flexible warming structure as defined in claim 12 wherein the plastic sheets are each selected from the group consisting of polyethylene terephthalate and polyamide resin.
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15. A transparent flexible warming structure as defined in claim 12 wherein the plastic sheets are polyethylene terephthalate and wherein one sheet is in the order of about 0.005 inch thick and the other sheet is in the range of from about 0.007 to 0.01 inch thick.
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16. A transparent flexible warming structure as defined in claim 12 wherein one of said plastic sheets has a relatively higher stiffness and the other plastic sheet has a relatively lower stiffness.
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17. A transparent flexible warming structure as defined in claim 12 wherein both sheets comprise polyethylene terephthalate of substantially equal thickness.
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18. A transparent flexible warming structure as defined in claim 12 wherein the pair of side edges are substantially equally spaced apart and wherein the heater layer is relatively wider at one portion between the side edges and relatively narrower in another portion between the side edges. 19. A transparent warming structure as defined in claim 18 wherein one of the high conductivity strips is longer than the other of the high conductivity strips.
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20. A transparent warming structure as defined in claim 12 wherein the total thickness is less than about 30 mils.
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21. A transparent flexible warming structure comprising:
- a first flexible transparent polyethylene terephthalate sheet having a pair of side edges;
an electrically conductive transparent heater layer over substantially all of one side of the sheet;
a second flexible transparent polyethylene terephthalate sheet bonded to the heater layer over substantially all of its area except a portion of a strip along each of the pair of side edges; and
a high conductivity strip electrically and mechanically bonded to the heater layer along each of the pair of side edges;
said polyethylene terephthalate sheets being substantially transparent in the visible spectrum and substantially opaque in bulk in the infrared spectrum, have a heat deformation of less than about 1 percent in any direction of about 150* F, at least one of said sheets having a sufficiently low vapor pressure to be vacuum metallizable, one of the sheets being in the order of about 0.005 inch thick and the other sheet being in the range of from about 0.007 to 0.01 inch thick, one of the sheets having a relatively higher stiffness and the other sheet having a relatively lower stiffness, and one of the sheets having a relatively higher infrared emittance and the other sheet has a relatively lower infrared emittance.
- a first flexible transparent polyethylene terephthalate sheet having a pair of side edges;
Specification