Abstract: A screw-on horseshoe formed from a plastic material is disclosed. A flex joint is provided that allows the horseshoe to expand and contract as pressure is applied to the horse's hoof, thereby reducing friction between the hoof and the shoe. The horseshoe also provides a lip portion projecting upwardly from a horseshoe base portion to protect the horse hoof wall from obstacles encountered during the movement of the horse. A novel screw having a double helix thread pattern including a high thread pattern and a low thread pattern is used to fasten the horseshoe to the horse's hoof without piercing the hoof wall. The screw includes a keyed recessed self-holding head that is complementary to, and therefore readily driven by, a power drill. A lightweight, yet wear-resistant, horseshoe that is readily attached to a horse's hoof with a minimum amount of labor and a minimum amount of damage to the hoof that can be constructed in many styles and sizes to match a large variety of horse uses is thus described.

Abstract: A multi-pane thermally insulative window has a frame assembly having side rails each including a central section, side sections pivotably connected to the central section, and splines which hold the side members in a position relative to the central members in which portions of the side members and central members exert pressure toward one another against opposite sides of the margins of each pane of the window. Gas-containing spaces defined between parallel panes communicate sealingly with the interior of expandable gas reservoirs to contain gas having a low thermal coefficient of conductivity as insulating layers between parallel panes. Infrared radiation reflective material is provided as a film contained between sheets of glass or as a coating on a pane of the window to provide additional thermal insulation with relatively low decrease of visible light transmission through the window.