Abstract: An inflatable structure includes a top end cap, a bottom end cap, a bladder attached to the top and bottom end caps and configured to hold pressurized air, a plurality of tethers disposed within the bladder, the inflatable structure moveable between a stowed profile and a final support profile, wherein the bladder is pressurized and expanded axially and the plurality of tethers are fully extended and restrict further movement of the top end cap and the bottom end cap away from one another and limit axial expansion of the bladder, a pulley assembly mounted within the bottom end cap, wherein in the stowed support profile, the plurality of tethers are wound onto the pulley assembly, the pulley assembly adapted to allow selective extension of the tethers allowing axial expansion of the bladder, wherein, the inflatable structure is adapted to provide multiple intermediary support profiles capable of supporting compressive loading.

Abstract: A method of monitoring a heating cycle of an induction heating system wherein an inductor encircles a metal workpiece and an alternating current is applied through the inductor from a power supply during the heating cycle. This method comprising the steps of generating an analog signal representative of the voltage across the inductor, as the voltage varies during the heating cycle by changes in the electromagnetic characteristics of the workpiece as the workpiece is being heated; digitizing the voltage representative analog signal; creating a trace of the digitized voltage representative analog signal, with the trace being indicative of the electromagnetic characteristic of the workpiece as sensed by the inductor voltage during the heating cycle; and, comparing the created trace with a preselected pattern.

Abstract: A method of monitoring a heating cycle of an induction heating system wherein an inductor encircles a metal workpiece and an alternating current is applied through the inductor from a power supply during the heating cycle. This method comprising the steps of generating an analog signal representative of the voltage across said inductor, as the voltage varies during said heating cycle by changes in the electromagnetic characteristics of the workpiece as the workpiece is being heated; digitizing the voltage representative analog signal; creating a trace of the digitized voltage representative analog signal, with the trace being indicative of the electromagnetic characteristic of the workpiece as sensed by the inductor voltage during the heating cycle; and, comparing the created trace with a preselected pattern.

Abstract: A power inverter particularly suited for use in applications requiring serially inductively heating workpieces in a predetermined manner, having a main inverter and an auxiliary starting inverter, in an arrangement in which the starting inverter is selectively applied and removed from the load in predetermined timed relationship with the application of the main inverter across the load, and providing a decrease in the inherent instability of the main inverter operation through an increase in the apparent Q of the load, while adjusting the output of the starting inverter to a value greater than the instability level of the main inverter.