Claims
- 1. Apparatus for heating plastic material in a mold comprising:
- a plurality of spaced apart pairs of electrodes disposed in a mold; and
- means for applying a radio frequency signal to each of said pairs of electrodes, each signal applied having a preselectable voltage, with said means for applying a radio frequency signal capable of applying different voltages to different pairs of electrodes.
- 2. The apparatus of claim 1 wherein one member from each of said plurality of pairs of electrodes is situated in a first planar array and the other member from each of said plurality of pairs of electrodes is situated in a second planar array.
- 3. An apparatus for deforming thermoplastic material comprising:
- heating means for heating the thermoplastic material to be formed, said heating means including first and second electrode assemblies and a radio frequency generator for producing an electric field between said first and second electrode assemblies;
- means for producing varying field strengths between selected portions of said electric field; and
- a mold situated between said first and second electrode assemblies, said mold having first and second opposing dielectric mold members for receiving the thermoplastic material to be deformed.
- 4. The apparatus of claim 3 wherein both of said first and second electrode assemblies include a plurality of electrode segments and said means for producing varying field strengths comprises means for selectively moving said electrode segments of each of said electrodes assemblies relative to one another.
- 5. The apparatus of claim 4 wherein said electrode segments of said first electrode assembly are contiguous to one another and said electrode segments of said second electrode assembly are contiguous to one another.
- 6. The apparatus of claim 3 wherein both of said first and second electrode assemblies include a plurality of electrode segments, and said means for producing varying field strengths comprises means for controlling said radio frequency generator to selectively apply variable radio frequency signals to selected pairs of said electrode segments of said first and second electrode assemblies.
- 7. The apparatus of claim 6 wherein said plurality of electrode segments of the first electrode assembly is arranged in a first planar array and said plurality of electrode segments of the second electrode assembly is arranged in a second planar array.
Parent Case Info
This application is a continuation of application Ser. No. 07/379,760, filed July 14, 1989 now abandoned.
US Referenced Citations (14)
Foreign Referenced Citations (3)
Number |
Date |
Country |
2361634 |
Jun 1975 |
DEX |
60-4026 |
Jan 1985 |
JPX |
585870 |
Feb 1947 |
GBX |
Continuations (1)
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Number |
Date |
Country |
Parent |
379760 |
Jul 1989 |
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