US 5,657,607 · Granted 1997-08-19
The Double-Glass Window Patent That Traps Heat With Tiny Pillars
Imagine two panes of glass separated by a tiny vacuum—like a thermos bottle for your windows. Microscopic pillars made of special glass glue hold them apart and create an airtight seal, keeping heat inside during winter and blocking it in summer. It's engineering meets physics to make homes cheaper to heat and cool.
The plain-English version
What it protects
The claim covers a two-layer glass panel design where glass sheets are held apart by small support pillars coated in solder glass, with a vacuum or low-pressure space between the panes. What's protected is the specific method of using preformed cores (often spherical) as spacers, coating them with fused solder glass to bond the sheets together, and the use of a pump-out tube to evacuate air and create the insulating void. The patent also protects adding extra solder glass film around the pillars to increase bonding strength.
Why it matters
This patent addresses a fundamental problem in building efficiency: heat loss through windows. By creating a vacuum-insulated glass panel, the design reduces thermal transfer far better than standard double-pane windows filled with air or inert gas. The innovation lies in how the pillars are engineered and assembled—a manufacturing challenge that, if solved elegantly, could reduce heating and cooling costs for buildings. The University of Sydney's approach using preformed cores and solder glass coatings offers a practical path to mass-producing these panels without the pillars collapsing under atmospheric pressure.
Real-world use
You'd encounter this technology in energy-efficient windows in homes and commercial buildings, especially in cold climates where keeping heat inside is critical to reducing energy bills and carbon footprint.
Original USPTO abstract
A thermally insulating glass panel comprises two spaced apart sheets of glass enclosing a low pressure space and interconnected by a peripheral joint of fused solder glass and an array of support pillars, and a pump-out tube used to provide communication between the low pressure space and the exterior of the panel during the creation of the low pressure space. The support pillars each comprise a preformed core of a selected geometry and a selected material and a coating of solder glass at least in the areas between the preformed core and the sheet glass. Preferably the preformed core is spherically shaped and completely coated by solder glass. The preformed core serves to separate the glass sheets during the heating process of the panel's fabrication when the solder glass is in its molten state, and the solder glass serves as a mechanical joint to support the glass sheets after solidification. Furthermore, to increase the strength of the mechanical joint, a thin film of solder glass may be placed in the vicinity of the support pillars on the glass sheets, thereby increasing the wetted area of the solder glass coating of the support pillar.
Patent details
- Publication number
- US 5,657,607
- Filing date
- 1995-09-11
- Grant date
- 1997-08-19
- Assignee
- University Of Sydney
- Inventor(s)
- COLLINS; RICHARD EDWARD, ROBINSON; STEPHEN JAMES
- CPC class
- E06B3/6612
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