The way this product worked was to flex the tray sidewise, thereby dislodging the ice from the tray. “Flexing the tray cracks the ice into cubes corresponding to the division points in the tray, and then forces the cubes up and out. Pressure forcing the ice out is due to the 5-degree draft on both sides of the tray,” wrote John T. Schaefer, engineering editor.
The company’s executives pointed out that water wasn’t required in the ice cube ejection process.