Gas Research Institute

Joel D Finegan

Randy J Bleske

James B Ross

David M Dickens

A dual plate heater provides two parallel temperature self-regulating heater plates or wire mesh comprising ferromagnetic material with one or more electrically energized coils parallel to and located between the heater plates which coil(s) when energized by a constant current or by an otherwise controlled current heat the plates to their Curie temperature or temperatures. The coil may be a flat spiral of thin conductive (copper) wire embedded in a thin layer of a heat conductive, electrically non-conductive material between said plates whereby heat energy generated in the coil is supplied to the heater plates. The dual plate heater may be employed to heat plastic pipes to their butt welding temperatures after which the heater is removed to the ends of the pipes to be joined are brought into contact under pressure. The dual plate heaters may also be employed in other arrangements such as shelves in a dispensing machine.

Dual surface heaters

A wrap tool having first and second coil regions and flange regions for inducing oscillating magnetic fields to fuse a plastic coupling having heating elements to a substrate. The first and second coil regions are wrapped around a selected plastic coupling and substrate to induce fusion currents causing melting and fusion of plastic pipes inserted into a magnetically energizable pipe coupling. The flange regions of the wrap tool are positioned adjacent each other overlappingly or inner surface to inner surface, permitting opposite current coil portions to cancel the other's magnetic fields and reduce coil inductance.

Wrap tool for magnetic field-responsive heat-fusible pipe couplings

A pipe scraper for removing a uniform amount of material from the perimeter of a pipe. The pipe scraper has a shoulder and biased members for urging the pipe against an interior surface of the scraper body to achieve a uniform scrape with both round and oval pipes, without a need for blade adjustment. Uneven scraping due to canting of the pipe with respect to the body is also eliminated.

Growing community of inventors

Fremont, CA, United States of America

Joel D Finegan