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:
Jun. 01, 2004
Filed:
Jul. 19, 2001
Clifford D. Tweedy, St. Charles, MO (US);
Theodore VonArx, La Crescent, MN (US);
Watlow Polymer Technologies, Winona, MN (US);
Abstract
The present invention provides immersion heating elements, water heaters and methods for their fabrication and use. In the first embodiment of this invention, a resistance heating element is provided which includes a resistance heating material and an electrically insulating, substantially water impervious sheath disposed over the resistance heating material to form an active element portion having an envelope of about 50 in , a total wattage of at least 1000 W, and a watt density of no greater than 60 W/in . Such an element has been demonstrated to substantially reduce scale reduction in water containing calcium, calcium carbonate, or both in solution.