The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 20, 2001
Filed:
Oct. 21, 1999
Donald M. Cunningham, Pittsburgh, PA (US);
Emerson Electric Co., St. Louis, MO (US);
Abstract
A metal sheath heating element for substantially dry applications is disclosed. In one embodiment, the heater is substantially elongate and cylindrical, and comprises a coiled resistive heater wire. The heater wire is disposed within a stainless steel outer sheath. Granular insulating material is introduced into the sheath to electrically insulate the heating element from the outer sheath, and to thermally conduct heat from the heating element to the sheath. At least one small hole is formed in outer sheath to permit any moisture trapped therein to escape, advantageously minimizing the potential for current leakage between the heating element and the outer sheath, as well as minimizing the likelihood of depletion of oxygen from the filler material due to oxidation occurring within the sheath. In one embodiment, a plurality of holes are formed at spaced intervals along the length of the sheath.