Electric heating – Heating devices – With heating unit structure
Reexamination Certificate
1999-12-29
2001-08-21
Hoang, Tu Ba (Department: 3742)
Electric heating
Heating devices
With heating unit structure
C219S212000, C219S528000, C219S529000
Reexamination Certificate
active
06278092
ABSTRACT:
BACKGROUND OF THE INVENTION
1) Field of the Invention
The present invention relates to a lagging device, especially to a lagging device which can be applied to the surface of a current object.
2) Description of the Prior Art
As the advance of technology, the warn-keeping or lagging of object is performed by electric heater or electric wrap other than by fire. The conventional electric wraps are used to keep user warm at clod weather or condition. However, they are bulky in application. The electric wrap generally comprises of a plug connected to AC power source and coil for generating heat. The user can put the portion with thermal coil to the location required to keep warm. However, the conventional electric wrap has following problems:
1. The heating coil is liable to oxidation and break and hard to repair due to the arrangement thereof being within the wrap.
2. The heating coil is generally controlled by a thermal sensor to keep constant power. However, the thermal sensor in different environment may have different response, even malfunction.
3. The heating coil may generate dangerous spark.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a lagging device which comprises a flexible and insulating substrate, flexible circuit plate on the substrate, a plurality of PTC ceramic resistors arranged alternatively on the flexible circuit plate, whereby the lagging device can be attached to a curve object.
It is still another object of the present invention to provide a lagging device the PTC resistor thereof can be attached directly to the portion to be kept warm.
It is still another object of the present invention to provide a lagging device which has isolation layer curving the PTC resistor thereof.
It is still another object of the present invention to provide a lagging device which has compact structure and can be easily attached to a curve portion.
It is still another object of the present invention to provide a lagging device which has not the problem of open circuit and external voltage failure when being applied to a curve surface.
It is still another object of the invention to provide a lagging device which is applicable to AC or DC power source.
The various objects and advantages of the present invention will be more readily understood from the following detailed description when read in conjunction with the appended drawing, in which:
REFERENCES:
patent: 4072848 (1978-02-01), Johnson et al.
patent: 5197329 (1993-03-01), Grundy
patent: 5663702 (1997-09-01), Shaw, Jr. et al.
patent: 5804797 (1998-09-01), Kaimoto et al.
patent: 5824996 (1998-10-01), Kochman et al.
Dougherty & Troxell
Hoang Tu Ba
LandOfFree
Lagging device does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Lagging device, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Lagging device will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2479381