Daniel Graham Hilton

US Patent:

57147388, Feb 3, 1998

Filed:

Jul 10, 1995

Appl. No.:

8/500745

Inventors:

Dana S. Hauschulz - Boulder CO
Daniel E. Hilton - Maryland Heights MO

Assignee:

Watlow Electric Manufacturing Co. - St. Louis MO
MKS Instruments, Inc. - Andover MA

International Classification:

H05B 358
B29B 700

US Classification:

219535

Abstract:

The flexible insulated heater includes a heater mat surrounded by an insulation jacket. The heater mat is preferably made of two layers of fiberglass reinforced rubber sheets laminated together with resistive heater wires sandwiched between the laminated sheets. The heater mat is formed with a curvature and size to fit snugly around the peripheral surface of the pipe that is to be heated. A jacket of thermally insulative material, such as a polymer foam, is molded over the external surface of the heater mat. The insulated jacket holds the heat generated by the heater mat from escaping radially outward, and it protects against burns to persons who might touch the heater. The mat and the jacket are configured so that the heater has interfacing opposite edges and that meet and preferably touch each other when the heater is mounted on the pipe, but the combination of the mat and jacket have sufficient resilient flexibility to allow opening the heater by separating the edges enough to slip the heater over the pipe, whereupon the heater resumes its original inherent cylindrical shape when released. Snaps, Velcro. TM. fastening material straps, or other suitable fasteners can be used to secure the heaters snugly around the pipe, if desired, although the biased resilience of the heater to its formed shape is generally sufficient itself to hold the heater in place.