US 12,127,309 B2Granted

PTC heating element and warming device including same for use in a patient warming system

AssigneeAmerican Sterilizer Company

InventorsRichard P. Nardo, Andrew Moss, John Michael Kasunich, Breese John Watson, Hugo van der Walt, Farhad Haghgoeian

Life of this patent

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Abstract

A heating element includes an electrically insulating layer; resistive layer formed of a positive temperature coefficient material; and an electrically conductive layer disposed between the electrically insulating layer and the resistive layer and including a first bus and a second bus that is spaced apart from the first bus, the resistive layer electrically connecting the first bus and the second bus. The electrically insulating layer, the electrically conductive layer, and the resistive layer are stacked to form a lamination and the lamination having a thickness and a width and length extending orthogonal to the thickness. The lamination may have slits extending through the thickness thereof and along a portion of the length thereof. Terminals may be connected to the buses and arranged to provide a counter current flow pattern across the lamination. The lamination may be used in a warming device and in connection with a patient warming system.

Claims17

Dependent claims

A heating element comprising:

an electrically insulating layer;
a resistive layer formed of a positive temperature coefficient material;
and
an electrically conductive layer disposed between the electrically insulating layer and the resistive layer and comprising a first bus and a second bus that is spaced apart from the first bus, wherein the first bus comprises a first bus base and first fingers that second fingers that extend from the second bus base toward the first bus base, the resistive layer electrically connecting the first bus and the second bus,
wherein
the electrically insulating layer, the electrically conductive layer, and the resistive layer are stacked to form a lamination and the lamination having a thickness and a width and length extending orthogonal to the thickness,
the first bus base extends along a first side of the lamination in the width direction and the first fingers extend from the first bus base in the length direction toward the second bus base;
the second bus base extends along a second side of the lamination opposite the first side in the width direction and the second fingers extend from the second bus base in the length direction toward the first bus base, the second fingers being interdigitated with the first fingers, and
a plurality of slits extend through the lamination in the thickness direction and along the length direction between the first bus base and the second bus base, the slits segmenting the lamination into parallel strips that each have a width that is less than a length thereof, each strip including a plurality of the first fin ers a plurality of the second fingers interdigitated with the plurality of the first fingers, and the resistive layer.

6 more elements

Dependencies are inferred from the claim text.

Facts

Application: 17/162,298Filed 29 Jan 2021 · us provisional application
Priority: 31 Jan 2020
Published: US 2021/0243843 A15 Aug 2021
Granted: 22 Oct 2024
Term ends: Not estimatedThe source records don’t support an estimate.

Classification15 codes

A61F 7/007
Heating or cooling appliances for medical or therapeutic treatment of the human body: characterised by electric heating
H05B 1/0294
For non specified applications: planar elements
A61F 7/0097
Heating or cooling appliances for medical or therapeutic treatment of the human body: blankets with active heating or cooling sources
A61F 7/08
Heating or cooling appliances for medical or therapeutic treatment of the human body: warming pads, pans or mats; Hot-water bottles