BRIEF DESCRIPTION OF THE DRAWINGS
Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiments with reference to the accompanying drawings, of which:
FIG. 1 is a plan view of the first preferred embodiment of a carbon fiber heating plate device according to the present invention;
FIG. 2 is a fragmentary perspective view of the first preferred embodiment;
FIG. 3 is a fragmentary plan view showing a portion of a carbon fiber wiring of the first preferred embodiment;
FIG. 4 is a fragmentary sectional view taken along line 4-4 of FIG. 2;
FIG. 5 is a plan view of the second preferred embodiment of the present invention;
FIG. 6 is a plan view of the third preferred embodiment of the present invention;
FIG. 7 is a perspective view of an anti-break unit used in the third preferred embodiment of the present invention;
FIG. 8 is a plan view of the fourth preferred embodiment of the present invention;
FIG. 9 is a plan view of the fifth preferred embodiment of the present invention;
FIG. 10 is a plan view of the sixth preferred embodiment of the present invention;
FIG. 11 is a plan view of the seventh preferred embodiment of the present invention; and
FIG. 12 is a plan view of the eighth preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Before the present invention is described in greater detail, it should be noted that like elements are denoted by the same reference numerals throughout the disclosure.
Referring to FIGS. 1 to 4, there is shown the first preferred embodiment of a carbon fiber heating plate device according to the present invention, which includes a high heat-resisting insulating plate 1 that has two opposite faces 100, 101, and two opposite edges 10, 11 each having a plurality of turning sites 12, 13 that are provided with a plurality of anti-break units 3, respectively. A carbon fiber wiring 2 is provided on one of the faces 100, 101 of the insulating plate 1 and has two ends for connection with an electric source (not shown).
The insulating plate 1 is preferably a mica plate that is highly resistant to heat. The carbon fiber wiring 2 is disposed over one of the faces 100, 101 of the insulating plate 1 and includes a single carbon fiber bundle 2A. The single carbon fiber bundle 2A is formed into a plurality of wire lines 22 that extends from the edge 10 to the edge 11, and a plurality of turns 23 formed at the turning sites 12, 13, respectively. Two ends of the carbon fiber bundle 2A are connected respectively to two conductors 14, 15 through two electric connecting members 16, 17, respectively. While the carbon fiber wiring 2 is formed from the single carbon fiber bundle 2A, it is contemplated that two or more than two carbon fiber bundles could be used to form the carbon fiber wiring 2.
Each edge 10, 11 of the insulating plate 1 is notched to form a plurality of indented edge parts 120, 130 to provide the turning sites 12, 13. Each turning site 12 thus includes two adjacent indented edge parts 120 and a flank 122 between the two adjacent indented edge parts 120. Similarly, each turning site 13 thus includes two adjacent indented edge parts 130 and a flank 132 between the two adjacent indented edge parts 130. Preferably, each indented edge part 120, 130 is substantially U-shaped.
The anti-break units 3 are provided at the respective turning sites 12, 13 to prevent the carbon fiber bundle 2A from contacting directly the sharp edges of the indented edge parts 120, 130. Each anti-break unit 3 is preferably made of a metal having high electrical conductivity. In this embodiment, a thin copper plate is used to make the anti-break units 3.
As best shown in FIGS. 1, 2 and 4, each anti-break unit 3 includes two opposite edge-covering members 30 and a flank-covering member 31 connected between the edge-covering members 30. Each edge-covering member 30 is a channel member 32 that substantially corresponds in shape to the corresponding indented edge part 120, 130 and that receives and clamps the corresponding indented edge part 120, 130. The flank-covering member 31 is a flat plate part that is connected between the two channel members 32 of the opposite edge-covering members 30 and that extends over the corresponding flank 122, 132.
Each turn 23 of the carbon fiber bundle 2A is a U turn formed at one of the turning sites 12, 13 and connects with two adjacent ones of the wire lines 22. In particular, each turn 23 is bent substantially by 90° at two adjacent indented edge parts 120, 130 and extends across the corresponding flank 122, 132. The carbon fiber bundle 2A is turned alternately at the edges 10, 11 of the insulating plate 1 to form the wire lines 22.
Referring once again to FIGS. 1 & 3, the carbon fiber bundle 2A have two conductive sleeves 20, 21 fitting around two ends of the carbon fiber bundle 2A, respectively, and connected to the respective electric connecting members 16, 17. A naked carbon fiber section 22A between the conductive sleeves 20, 21 has a plurality of naked carbon fibers.
The anti-break units 3 serve to protect the carbon fiber bundle 2A from breaking due to the turning of the carbon fiber bundle 2A at the sharp edges 10, 11 of the insulating plate 1. As the indented edge parts 120, 130 are covered by the anti-break units 3, the carbon fiber bundle 2A is prevented from contacting directly the indented edge parts 120, 130. In addition, when an electric current is applied to the carbon fiber bundle 2A to produce heat, the temperature of the carbon fiber bundle 2A at the turns 23 can be higher than that of the remaining parts of the carbon fiber bundle 2A. Due to the presence of the anti-break units 3 according to the present invention, the high temperature heat produced in the turns 23 can be minimized. This is because, when the electric current flows to the turns 23 of the carbon fiber bundle 2A, the electric current will flow through the anti-break units 3 rather than the turns 23 since the electrical conductivity of the anti-break units 3 is higher than that of the turns 23. As such, the temperature of the carbon fiber bundle 2A at the turns 23 may be lowered, and an incidence that the carbon fiber bundle 2A will burn due to high temperature may be reduced.
Referring to FIG. 5, there is shown the second preferred embodiment of the present invention which differs from the first preferred embodiment in that the carbon fiber wiring 2 is formed by using a plurality of carbon fiber bundles 2A′. Each carbon fiber bundle 2A′ is disposed in one of a plurality of regions 4 on the insulating plate 1 and is formed into at least three wire lines 22. A pair of conductors 14, 15 are provided to extend along and proximate to the two edges 10, 11 of the insulating plate 1, respectively. Each carbon fiber bundle 2A′ has two conductive sleeves 20, 21 connected respectively to the conductors 14, 15 through the respective electric connecting members 16, 17. Preferably, the electric connecting members 16, 17 are riveted to the respective anti-break units 3 and the insulating plate 1 by using rivets (not shown) that extend through the respective flank-covering members 31 of the anti-break units 3. The electric connecting members 16, 17 and the anti-break units 3 are therefore secured to the insulating plate 1. The two conductive sleeves 20, 21 of each carbon fiber bundle 2A′ are connected electrically and respectively to the electric connecting members 16, 17. As such, the carbon fiber bundles 2A′ are interconnected electrically in parallel. With the carbon fiber wiring 2 of this embodiment, the making of a long heating plate device is possible. In case a single carbon fiber bundle is used in making a long heating plate device, the carbon fiber bundle must be very long. As the power output of the carbon fiber bundle is likely to decrease as the length of the carbon fiber bundle increases, a very long carbon fiber bundle cannot provide a uniform heating. Since the carbon fiber bundles 2A′ used in this embodiment are relatively short and operate independently, uniform heating can be achieved.
Referring to FIGS. 6 and 7, there is shown a third preferred embodiment of the present invention which differs from the first embodiment in that a carbon fiber wiring 2′ is provided to extend over two opposite faces 100, 101 of the insulating plate 1, that each indented edge parts 120, 130 serves as a turning site, and that each anti-break unit 3′ has a single edge-covering member 30′ covering one of the indented edge parts 120, 130. The single edge-covering member 30′ is formed as a channel member. The carbon fiber wiring 2′ includes a single carbon fiber bundle 2A that is wound around the insulating plate 1 by turning the single carbon fiber bundle 2A about the indented edge parts 120, 130. In particular, the single carbon fiber bundle 2A is bent at each indented edge part 120, 130 to extend from one of the faces 100, 101 to the other one of the faces 100, 101, thereby forming a plurality of spaced apart wire lines 22′ on the two faces 100, 101 and a plurality of turns 23′ at the indented edge parts 120, 130, respectively.
Referring to FIG. 8, there is shown a fourth preferred embodiment of the present invention which differs from the third preferred embodiment in that a carbon fiber wiring 2′ disposed on two faces 100, 101 of the insulating plate 1 is formed from a plurality of carbon fiber bundles 2A′ each of which is wound around the insulating plate 1 in one of the regions 4 of the insulating plate 1 to form at least three wire lines 22′ and which are interconnected electrically through a parallel connection. Each carbon fiber bundle 2A′ has two conductive sleeves 20′, 21′ connected electrically to conductors 14, 15 through conductive connecting members 16, 17, respectively.
Referring to FIG. 9, there is shown a fifth preferred embodiment of the present invention which differs from the third preferred embodiment in that the insulating plate 1 is a vertical type insulating plate that has a bottom side 102 and a top side 103 and that the spacing between the wire lines 22′ decreases from the bottom side 102 to the top side 103. In other words, the spacing (I) proximate to the bottom side 102 is smaller than the spacing (II) proximate to the top side 103. As the wire lines 22′ are distributed more densely at the lower part of the insulating plate 1 compared to the upper part thereof, the heating temperature provided by the carbon fiber bundle 2A is higher at the lower part. The air heated by the high temperature heat at the lower part of the insulating plate 1 can flow upward to serve as a natural heating medium to heat the upper part of the insulating plate 1.
Referring to FIG. 10, there is shown the sixth preferred embodiment of the present invention which differs from the fourth preferred embodiment in that the wire lines 22′ are fixed to the face 100 of the insulating plate 1 using a plurality of thermally conductive adhesive tapes 5 that extend over the wire lines 22′, respectively, so that the wire lines 22′ are prevented from becoming loosened when the insulating plate 1 is placed vertically.
Referring to FIG. 11, there is shown the seventh preferred embodiment of the present invention which differs from the fourth preferred embodiment in that two heat-resistant insulative protection strips 6 are adhered to the face 100 of the insulating plate 1 along the two edges 10, 11 to cover and protect the turns 23′ and the conductive sleeves 20′, 21′ of the carbon fiber bundles 2A′, the conductors 14, 15, and the electric connecting members 16, 17. Alternatively, the protection strips 6 may be adhered to both of the faces 100, 101 of the insulating plate 1.
Referring to FIG. 12, there is shown the eighth preferred embodiment of the present invention which differs from the seventh preferred embodiment in that an additional heat-resistant insulative cover plate 7 is disposed over one or two of the faces 100, 101 between the protection strips 6 so as to cover and protect the wire lines 22′ of the carbon fiber bundles 2A′. Preferably, the cover plate 7 is formed of mica strips or plates which have good heat-absorbing and heat-dissipating characteristics.
As described hereinbefore, the anti-break units 3, 3′ are made of a high heat-resisting metal, such as, copper. However, it is contemplated that the anti-break units 3, 3′ could be made of a heat-resisting plastic plate or tape to cover the indented edge parts 120, 130 and the flanks 122, 132 of the insulating plate 1.
While the present invention has been described in connection with what is considered the most practical and preferred embodiments, it is understood that this invention is not limited to the disclosed embodiments but is intended to cover various arrangements included within the spirit and scope of the broadest interpretation so as to encompass all such modifications and equivalent arrangements.
Patent Application
20070241166
