Patent Application
20060102616
1. Field of the Invention
This invention relates to an electrothermal article, such as an electric blanket, a mattress pad, a heating pad, and the like, more particularly to an electrothermal article including a plurality of elongated flat heating elements that have two grouped end portions.
2. Description of the Related Art
Electrothermal articles commonly used in our daily life include electric blankets and mattress pads. As shown in
Therefore, the object of the present invention is to provide an electrothermal article that eliminates the aforesaid drawbacks of the prior art.
According to this invention, there is provided an electrothermal article including a fabric member that defines an inner space therein, a connector disposed outwardly of the inner space in the fabric member and including conductive first and second terminals, and a plurality of elongated flat heating elements disposed in the inner space in the fabric member. Each of the heating elements has first and second end portions. The first end portions of the heating elements are grouped into a first bundle and are connected electrically to the first terminal of the connector. The second end portions of the heating elements are grouped into a second bundle and are connected electrically to the second terminal of the connector.
Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiment of the invention, with reference to the accompanying drawings, in which:
Referring to
Referring to
In addition, the fabric member 3 further defines a heating area between the upper and middle fabric sheets 30, 300. Each of the elongated flat heating elements 41 further has an intermediate portion 410 that extends between the first and second end portions 400, 401. The intermediate portions 410 of the elongated flat heating elements 41 are distributed across the heating area, and are sandwiched between the upper and middle fabric sheets 30, 300. The connector 2 is adapted to be electrically connected to a power supply (not shown) for activating the elongated flat heating elements 41 to generate heat, which spreads evenly through the heating area.
Preferably, the fabric member 3 is rectangular in shape, and has a first corner and a second corner which are disposed diagonally opposite to each other, a first side 301 that extends from the first corner, and a second side 302 that is transverse to and that extends from the first side 301 to the second corner 302. The first bundle is disposed adjacent to the first corner and the second bundle extends from the first corner to the second corner along the first and second sides 301, 302.
In this embodiment, an adhesive layer 5 is disposed between the upper and middle fabric sheets 30, 300 for bonding the intermediate portions 410 of the elongated flat heating elements 41 to the upper and middle fabric sheets 30, 300. The adhesive layer 5 is made from an adhesive material having a melting point lower than that of the upper, middle, and lower fabric sheets 30, 300, 31. Preferably, the adhesive material is selected from the group consisting of polyamide and polyethylene.
The lower fabric sheet 31, the upper fabric sheet 30 bonded with the intermediate portions 410 of the elongated flat heating elements 41, and the middle fabric sheet 300 are stitched together through interlaced stitching threads 34. The heating area is confined by a peripheral stitching thread 33.
In this embodiment, since each of the elongated flat heating elements 41 are formed from the carbon fiber filaments, the elongated flat heating elements 41 in the heating area can be conveniently arranged in such a manner that they will not be pierced during a stitching operation by a needle of a sewing machine. Even if a small portion of the filaments of the elongated flat heating elements 41 is damaged by the needle of the sewing machine, operation of the electrothermal article will not be affected.
Furthermore, since the first and second end portions 400, 401 of the elongated flat heating elements 41 which are grouped into the first and second bundles are disposed outwardly of the heating area and the intermediate portions 410 of the elongated flat heating elements 41 are evenly distributed across the heating area, the electrothermal article of this invention is softer and more flexible compared with the conventional electrothermal article.
In addition, as the elongated flat heating elements 41 of the electrothermal article according to this invention are made from carbon fiber, they will not easily break upon bending or during washing operation.
While the present invention has been described in connection with what is considered the most practical and preferred embodiment, it is understood that this invention is not limited to the disclosed embodiment but is intended to cover various arrangements included within the spirit and scope of the broadest interpretations and equivalent arrangements.
