Abstract: This application relates to a self-contained apparatus for mechanically turning individual workpieces travelling on a conveyor, such as lengths of lumber travelling into or exiting from a sawmill. The invention reduces the need for lumber graders to turn lumber manually and thereby helps avoid repetitive motion injuries. The apparatus includes an adjustable height frame which is positionable alongside the conveyor. The frame supports a workpiece holder defining an open-ended slot for temporarily receiving an end portion of a workpiece. When the end of a lumber board or other workpiece is received within the holder, a proximity sensor causes the holder to rotate, thereby turning the workpiece lengthwise 180 degrees. The workpiece is then deposited on to the conveyor in its inverted orientation for further travel thereon. The apparatus may also optionally permit workpieces to pass through the holder when a “skip” rather than an “invert” signal is received.

Abstract: A method and apparatus for converting a conventional mechanical or hydraulic system for driving the infeed and outfeed rolls of a planer mill or a similar conveyor to variable frequency electric power. The method involves disconnecting the roller shafts from pre-existing mechanical and hydraulic drive components housed within the conveyor gearbox or other support frame. The electric motors are mounted at fixed positions on a panel rigidly connected to the gearbox or other support frame at a location spaced-apart from the roller shafts. Each motor is coupled to a corresponding roller shaft by means of a connector drive shaft having universal joint couplers at each end thereof. This arrangement permits displacement of the roller shafts during normal operation of the conveyor without transferring torque forces to the electric motors. The speed of each motor and hence each roller may be independently controlled by a frequency inverter which is operable by remote control.