Abstract: A series of inverter assemblies are spaced across a board conveyor with each assembly including a plate having an abutment to arrest the board and a lifting surface. An extension on the plate provides a supplementary lifting surface and further a curved edge which stops the following board (s) during cycling of the inverter assembly. A control system includes both manually actuated switches as well as board actuated limit switches in circuit with an adjustable delay component for regulating cycling of the inverter assemblies.