Method for preparing a heater glazing for a refrigerated display case

• US 5,449,885 A
• Filed: 08/23/1994
• Issued: 09/12/1995
• Est. Priority Date: 03/05/1991
• Status: Expired due to Fees

• Current Assignee: Saint-Gobain Vitrage International
• Original Assignee: Saint-Gobain Vitrage International
• Inventors: Vandecastele, Bruno
• Primary Examiner(s): Paschall, Mark H.
• Assistant Examiner(s): SWITZER, MICHAEL
• Application Number:
  US08/294,782
• Time in Patent Office: 385 Days
• Field of Search: 219/201, 219/218, 219/203, 219/547, 219/522, 219/543, 219/549, 312/116, 312/114, 62/248, 62/458
• US Class Current: 219/522
• CPC Class Codes: A47F 3/0434 Glass or transparent panels
• CPC Class Codes: H05B 2203/011 Heaters using laterally extending conductive material as connecting means
• CPC Class Codes: H05B 2203/013 Heaters using resistive films or coatings
• CPC Class Codes: H05B 3/141 Conductive ceramics, e.g. metal oxides, metal carbides, barium titanate, ferrites, zirconia, vitrous compounds
• CPC Class Codes: H05B 3/84 Heating arrangements specially adapted for transparent or reflecting areas, e.g. for demisting or de-icing windows, mirrors or vehicle windshields

Abstract

A display glazing which is fitted to a refrigerated display case and which prevents moisture condensation thereon, comprising a shaped glazing having at least a portion of one side thereof provided with a low emissivity coating, conductive current input strips placed on the glazing in contact with the low emissivity coating which define coated zones of the glazing which are heated by the Joule effect upon the passage of electrical current between the conductive strips, and a means for determining if atmospheric conditions are such that condensed moisture is likely to form on the exterior surface of the unheated glazing.

Claims

1. A method of preventing moisture condensation on the display single glazing of a refrigerated display case, comprising:

providing at least a portion of the inside surface of the display glazing with a low emissivity conductive coating and conductive strips for current input placed in a vertical plane and being shorter than the dimension of the glazing and the low emissivity conductive coating in their vertical plane in contact with the coating which define at least one heating zone;

applying electrical current to the conductive strips to generate heat by the Joule effect in the coating bounded by the conductive strips if atmospheric conditions are such that moisture condensation is likely to occur on the glazing, and

wherein the low-emissivity coating is interrupted by an insulating strip between the part of the surface of the single glazing which is subjected to heating by the Joule effect and the remainder of the surface along a line which joins the ends of the current input strips.

2. The method of claim 1, wherein a mist detector is employed to control heating of the glazing as it determines the moisture conditions of the atmosphere.

3. The method of claim 1, wherein said mist detector is on the outside surface of the glazing.

4. A method of providing a refrigerated display case with a display glazing which prevents the formation of vision obscuring surface condensed moisture, which comprises:

equipping said display case with a display glazing comprising;

a shaped single glazing having at least a portion of its inside surface thereof provided with a low emissivity coating;

conductive current input strips placed in a vertical plane, said input strips being shorter than the dimension of the glazing and the low emissivity conductive coating in their vertical plane, on the glazing in contact with the low emissivity coating which define coated zones of the glazing which are heated by the Joule effect upon the passage of electrical current between the conductive strips,

wherein the low-emissivity coating is interrupted by an insulating strip between the part of the surface of the single glazing which is subjected to heating by the Joule effect and the remainder of the surface along a line which joins the ends of the current input strips; and

a means for determining if atmospheric conditions are such that condensed moisture is likely to form on the exterior surface of the unheated glazing.