Ceramic heater/fuser roller with internal heater
First Claim
1. A thermal conduction roller, comprising:
- a tubular roller core having a hollow inside;
an electrical insulator coat disposed on the inside of the roller core and having a thickness in a range from about 5 mils to about 100 mils;
a heater coat comprising a ceramic material that is disposed over the insulating coat; and
at least two electrical contact assemblies that are disposed inside the roller core and provide continuous electrical connection to the heater coat as the roller is being rotated;
wherein each of the two electrical contact assemblies further comprises a disk fastened to rotate with the roller core;
a resilient element attached to said disk and urged into electrical connection with said heater coat; and
an electrical connection in contact with said disk as it rotates with said roller core.
11 Assignments
0 Petitions
Accused Products
Abstract
A thermal conduction roller (10) has a tubular roller core (11) with an inside surface; and an electrical insulator coat (16) primarily of zirconia on the inside surface, a heater coat (18) of titania or a titania blend is disposed over the insulator coat (16), and at least two electrical contact assemblies that are disposed inside the roller and electrically connect to the heater coat (18) as the roller (10) is being rotated. One embodiment utilizes an electrical insulator coat (16) in a range of thickness from about ten mils to about twenty mils. A thinner coat may not have sufficient dielectric strength, while a thicker coat decreases thermal conduction. A release material (12) is applied to the outside of the roller (10). Various contact structures according to the present invention are also described in detail, including one especially adapted to connect to a three-phase power supply.
52 Citations
28 Claims
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1. A thermal conduction roller, comprising:
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a tubular roller core having a hollow inside;
an electrical insulator coat disposed on the inside of the roller core and having a thickness in a range from about 5 mils to about 100 mils;
a heater coat comprising a ceramic material that is disposed over the insulating coat; and
at least two electrical contact assemblies that are disposed inside the roller core and provide continuous electrical connection to the heater coat as the roller is being rotated;
wherein each of the two electrical contact assemblies further comprises a disk fastened to rotate with the roller core;
a resilient element attached to said disk and urged into electrical connection with said heater coat; and
an electrical connection in contact with said disk as it rotates with said roller core.- View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A thermal conduction roller, comprising:
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a tubular roller core having a hollow inside;
an electrical insulator coat on the inside of the roller core and having a thickness in a range from about 5 mils to about 100 mils;
a heater coat comprising a ceramic material that is disposed over the insulating coat;
at least two electrical contact assemblies that are disposed inside the roller core and provide continuous electrical connection to the heater coat as the roller is being rotated; and
further comprising at least one additional contact assembly disposed in between said first-mentioned contact assemblies to divide the heater coat into zones. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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21. A thermal conduction roller, comprising:
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a tubular roller core having a hollow inside;
an electrical insulator coat disposed inside the roller core and having a thickness in a range from about 5 mils to about 100 mils;
a heater coat comprising a ceramic material that is disposed over the insulating coat; and
at least two electrical contact assemblies that are disposed inside the roller core and provide continuous electrical connection to the heater coat as the roller is being rotated wherein each of the two electrical contact assemblies is supported by a disk and comprises a spring disposed on said disk and urged into electrical connection with said heater coat, and an electrical connection to said disk. - View Dependent Claims (22, 23, 24, 25, 26, 27, 28)
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Specification