US Patent 7786408 Bus bar interfaces for flexible heating elements

A flexible heating subassembly, which may be incorporated in an electric warming blanket or any other type of flexible heater, includes a single heater, which is preferably formed from an electrically conductive polymeric fabric. The subassembly further includes first and second conductive bus bars, each extending alongside a respective first and second edge of the heater, each being coupled to the heater by at least one row of stitching that extends along the respective bus bar. The edges of the heater may be folded over respective bus bars for coupling and each of the bus bars may terminate just beyond opposing ends of the heater. A ribbon of conductive material may be interposed between each of the bus bars and the heater.