WARM WINDOW BUSS BAR SYSTEM AND SAFETY MECHANISM

• US 20080135543A1
• Filed: 01/04/2008
• Published: 06/12/2008
• Est. Priority Date: 06/07/2005
• Status: Active Grant

• Current Assignee: Energized Glass, LLC
• Original Assignee: Energized Glass, LLC
• Inventors: Lundahl, Dave, Johnson, Steven X.
• Granted Patent: US 8,530,793 B2
• Time in Patent Office: Days
• US Class Current: 219/522
• CPC Class Codes: F24D 13/026 in door, windows
• CPC Class Codes: H05B 2203/016 Heaters using particular connecting means
• CPC Class Codes: H05B 3/03 Electrodes
• CPC Class Codes: H05B 3/22 non-flexible
• 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
• CPC Class Codes: Y02B 30/00 Energy efficient heating, ventilation or air conditioning [HVAC]

Abstract

Disclosed is a warm window system that utilizes individual buss bars that are placed within the space between an inside window pane and an outside window pane and creates sufficient physical force to create an electrical contact on the tin oxide layer on the inside surface of the inside pane of glass. The buss bars have a modulus of elasticity to ensure sufficient electrical contact with the tin oxide layer to prevent the formation of hot spots and securely hold the buss bars in place. Both a z buss bar and c buss bar are also disclosed that are capable of generating a sufficient amount of reactive force to create a secure contact with a tin oxide layer on the interior surface of an interior pane of glass in a warm window system to hold the buss bar in place and provide a large contact surface area to provide sufficient electrical contact with the tin oxide layer to prevent hot spots. A safety circuit is also disclosed that utilizes a controller that generates a control signal to apply the ac power signal to the warm window system in response to a low voltage dc signal that is applied to an isolated strip of conductive material on the inner pane of glass that detects if the glass is broken. The low voltage signal does not provide a shock hazard and safely detects the status of the inner pane of glass.

Claims

1. A warm window system comprising:

an outside pane of glass;

an inside pane of glass that is coated with a tin oxide layer over substantially all of a inner surface of said inside pane of glass;

at least one spacer that is disposed between said inside pane of glass and said outside pane of glass in a peripheral area, said inside pane of glass and said outside pane of glass being substantially aligned so that said inner surface of said inside pane of glass faces an interior portion of said warm window system;

at least two buss bars placed in said interior portion of said warm window system adjacent to said at least one spacer, said buss bars comprising;

a first base portion that is disposed adjacent to an inside surface of said outside pane;

a first arm portion that is connected to said first base portion and forms an acute angle from said first base portion;

a second base portion that is disposed adjacent to an inside surface of said outside pane;

a second arm portion connected to said second base portion that forms an acute angle between said second base portion;

a curved contact surface connected to said first arm portion and said second arm portion that flattens when said buss bar is compressed between said outside pane of glass and said inside pane of glass, said buss bars having a modulus of elasticity that causes said contact surface to be forced against said inner surface of said inside pane of glass, resulting in said contact surface producing a sufficient amount of physical force on said inner surface of said inside pane of glass to create an electrical contact between said contact surface and said tin oxide layer on said inner surface of said inside pane of glass so that said contact surface is capable of carrying a sufficient current to warm said warm window system, and a sufficient amount of physical force to hold said buss bars in a substantially stationary position in said interior portion of said warm window system.

2. A method of applying current to a tin oxide layer in a heated window system comprising:

assembling a first pane of glass, having said tin oxide layer disposed on an inner surface of said first pane of glass, at least one spacer and a second pane of glass;

providing at least two buss bars comprising;

a first base portion that is disposed adjacent to an inside surface of said outside pane;

a first arm portion that is connected to said first base portion and forms an acute angle from said first base portion;

a second base portion that is disposed adjacent to an inside surface of said outside pane;

a second arm portion connected to said second base portion that forms an acute angle between said second base portion;

said buss bars having a modulus of elasticity that causes said buss bars to produce a sufficient amount of physical force on said tin oxide layer disposed on said inner surface of said first pane of glass to create an electrical contact between said buss bars and said tin oxide layer disposed on said inner surface of said first pane of glass that is capable of carrying a sufficient current to warm said heated window system, and a sufficient amount of physical force to hold said buss bars in a substantially stationary position in said heated window system;

placing said at least two buss bars between said first pane of glass and said second pane of glass;

applying a current to one of said at least two buss bars so that current flows between said at least two buss bars and through said tin oxide layer.

3. A warm window system comprising:

an outside pane of glass;

an inside pane of glass that is coated with a tin oxide layer over substantially all of an inner surface of said inside pane of glass;

at least one spacer that is disposed between said inside pane of glass and said outside pane of glass in a peripheral area, said inside pane of glass and said outside pane of glass being substantially aligned so that said inner surface of said inside pane of glass faces an interior portion of said warm window system;

at least two buss bars placed in said interior portion of said warm window system adjacent to said at least one space, said buss bars comprising;

a first base portion that is disposed adjacent to an inside surface of said outside pane;

a second base portion that is disposed adjacent to an inside surface of said outside pane;

a curved contact surface connected to said first base portion and said second base portion that flattens when said buss bar is compressed between said outside pane of glass and said inside pane of glass, said buss bars having a modulus of elasticity that causes said contact surface to be forced against said inner surface of said inside pane of glass, resulting in said contact surface producing a sufficient amount of physical force on said inner surface of said inside pane of glass to create an electrical contact between said contact surface and said tin oxide layer on said inner surface of said inside pane of glass so that said contact surface is capable of carrying a sufficient current to warm said warm window system, and a sufficient amount of physical force to hold said buss bars in a substantially stationary position in said interior portion of said warm window system.

4. A method of applying current to a tin oxide layer in a heated window system comprising:

assembling a first pane of glass, having said tin oxide layer disposed on an inner surface of said first pane of glass, at least one spacer and a second pane of glass;

providing at least two buss bars comprising;

a first base portion that is disposed adjacent to an inside surface of said outside pane;

a second base portion that is disposed adjacent to an inside surface of said outside pane;

said buss bars having a modulus of elasticity that causes said buss bars to produce a sufficient amount of physical force on said tin oxide layer disposed on said inner surface of said first pane of glass to create an electrical contact between said buss bars and said tin oxide layer disposed on said inner surface of said first pane of glass that is capable of carrying a sufficient current to warm said heated window system, and a sufficient amount of physical force to hold said buss bars in a substantially stationary position in said heated window system;

placing said at least two buss bars between said first pane of glass and said second pane of glass, applying a current to one of said at least two buss bars so that current flows between said at least two buss bars and through said tin oxide layer.

5. A method of controlling application of an ac power signal to a warm window system comprising:

providing a first conductive layer disposed on a first pane of glass in said warm window system;

providing a second conductive layer disposed on a second pane of glass in said warm window system;

connecting said first conductive layer to said second conductive layer disposed on a second pane of glass of said warm window system;

connecting said second conductive layer to a control terminal on a relay that controls activation of power terminals on said relay;

connecting said ac power signal to said power terminals;

generating a low voltage dc voltage signal wherever a controller detects that said ac power signal is to be applied to said warm window system;

applying said low voltage dc signal to said first conductive layer disposed on said first pane of glass of said warm window system to complete a circuit through said first conductive layer when said first pane of glass is not broken and said second conductive layer when said second pane of glass is not broken, so that said low voltage dc signal is applied to said control terminals on said relay to activate said relay and cause said ac power signal to be applied to said warm window system.

6. The method of claim 5 wherein said process of providing a first conductive layer comprises providing a first conductive layer that is an isolated strip on said first pane of glass.

7. The method of claim 5 wherein said process of providing a second conductive layer comprises providing a second conductive layer that is an isolated strip on said second pane of glass.

8. The method of claim 6 further comprising:

applying a low voltage current signal to a thermocouple that is coupled to said first pane of glass;

determining the temperature of said first pane of glass by monitoring said low voltage current signal;

generating said low voltage dc signal in response to said low voltage current signal.

9. A safety circuit that controls the application of an ac power signal to a warm window system comprising:

a controller that generates a low voltage dc signal whenever said ac power signal is to be applied to said warm window system;

a first conductive layer disposed on a first pane of glass of said warm window system that is connected to receive said low voltage dc signal;

a second conductive layer disposed on a second pane of glass of said warm window system that is connected to said first conductive layer to receive said low voltage dc signal;

a relay that has ac power terminals that are connected to said ac power signal and a control terminal that is connected to said second conductive layer that receives said low voltage dc signal and activates said power terminals in response to receipt of said low voltage dc signal on said control terminal to apply said ac power signal to said warm window system.

10. The safety circuit of claim 9 further comprising:

a low voltage current signal generated by said controller;

a thermocouple that is coupled to said first pane of glass that controls said low voltage current signal in accordance with the temperature of said first pane of glass.

11. The safety circuit of claim 10 wherein said first conductive layer comprises an isolated strip of conductive material disposed on said first pane of glass.

12. The safety circuit of claim 10 wherein said second conductive layer comprises an isolated strip of conductive material disposed on said second pane of glass.