Dust evacuation and tool interlock

In a wood working tool having an electrical drive motor with electrical power supply means and an electrical starter switch in electrical circuit thereto and a dust collector system having a dust collector including a dust evacuation duct extending to a dust removal position adjacent said wood working tool and means to apply subatmospheric pressure to said dust evacation duct, the improvement comprising an interlock between said collector system and said wood working tool which includes a port in said evacuation duct adjacent said wood working tool, a normally off pressure responsive means having a pressure inlet port in communication with said port in said evacuation duct and in electrical circuit to said electrical starter switch, whereby the application of subatmospheric pressure from said evacuation duct to said pressure responsive means permits application of electrical power from said electrical power supply means and operation of said drive motor.