Abstract: An insulated glass panel has a frame and spacer structure which prevents foreign matter and moisture from entering between spaced panes while affording low-cost manufacture and repair. The spacer has a pair of opposed recesses mounting beads of resiliently deformable cured elastomeric material, and the beads are compressed against the spacer by the frame which surrounds the periphery of the panes. In certain embodiments, the frame comprises a pair of frame members disposed side by side to form a hollow cavity around the periphery of the panes and snap fasteners releasably connecting the frame members together. The cavity is filled with a foam plastic material which surrounds reinforcing elements located at the corners of the frame to rigidify the frame. In one embodiment, the frame members are hinged together to permit them to pivot relative to one another between open and closed positions about an axis parallel to the edges of the panes to afford installation and replacement of the panes.

Abstract: A frangible panel having an electrically-energizable layer carried in an area thereof for heating the panel and main circuit means for supplying electrical power to the layer is provided with circuit breaker means operable to interrupt electrical power to the layer upon breakage of the panel. The circuit breaker means includes a fusible link connected in series with the layer and a solid-state control device connected in the main circuit in parallel with the layer. The solid-state device has a control gate which is connected to a sensing circuit surrounding the electrically-energizable layer and which is connected in the main circuit to render the solid-state control device non-conductive as long as the sensing strip is continuous and to render the solid-state control device conductive when the sensing circuit is broken. Thus, the solid-state control device connects the fusible link to ground and causes the link to blow, thereby interrupting power to the electrically-energized layer.