Abstract: A melting furnace includes a crucible surrounded by a wall to form an annular heating chamber. A burner provides a long combustion flame which circulates through the annular chamber to heat the exterior of the crucible. The combustion flame and hot gases in this chamber are exhausted through a stack having a first exhaust port at the top of the stack and a second exhaust port on the side of the stack. A duct, connected to the stack at the second port, provides a path for ducting the combustion flame and gases into the mouth of the crucible to melt a charge therein.The first exhaust port is selectively opened and closed, as by a damper, to alternatively direct the combustion flame and gases either (a) through the first port to the atmosphere, or (b) through the second port, into the duct, and into the mouth of the crucible. When the first port is open, noxious fumes from the crucible are advantageously drawn through the duct and into the exhaust stack.

Abstract: A skateboard having an adjustable feature to vary board flexibility to accommodate the performance requirements of various maneuvers executed by the individual using the skateboard. Variable board flexibility is accomplished by the use of a strengthening member mounted on the bottom of the skateboard by an adjusting mechanism which varies the connection between the strengthening member and the skateboard. The skateboard also incorporates integrally cast wheel assembly mounting brackets located on the bottom of the respective ends of the skateboard. In one embodiment of the variable flexion skateboard adjustment dials are positioned at each end of the strengthening member to set the desired flexibility in the skateboard.

Abstract: An aluminum casting alloy having superior foundry characteristics, being heat-treatable to ultra-high yield strength, and containing from about 3 to about 10% silicon about 0.7 to about 1.5% magnesium, from about 0.03 to about 1% beryllium, and from 0.05 to 1% titanium and a method for preparing such alloys is disclosed.