Abstract: The invention provides a bandmill having an endless loop of bandsaw blade which is automatically strained to a desired tension, and automatically driven at an accurate location or tracking position. The bandmill runs on a pair of spaced co-planar wheels, which are forced longitudinally apart to apply strain to the bandsaw. Actual saw strain is automatically detected by a force transducer within the strain mechanism, and the actual saw strain is automatically compared electronically with a desired saw strain. A servo-controller automatically adjusts distance between the wheels to vary force therebetween so that actual saw strain is varied to approach the desired saw strain. Also, actual tracking of the saw blade relative to the wheels is automatically sensed by sensors located adjacent the edge of the saw blade.

Abstract: A bandmill has first and second wheels and an endless saw blade trained about the wheels. The wheels are mounted to rotate about respective axes which lie in a common plane, but the first wheel is adjustable in position relative to the second wheel with respect to both its distance from the second wheel and its orientation relative to the second wheel. A tensioning mechanism is effective to force the first wheel away from the second wheel, while maintaining the axes of rotation of the two wheels substantially parallel, in response to a signal which is provided by a load cell and represents the tension in the saw blade. A wheel tilt mechanism is effective to adjust the angular position of the first wheel relative to the second wheel in response to a signal indicating the path followed by the saw blade, for maintaining the blade on a proper path.

Abstract: A board separator apparatus includes an input conveyor for longitudinally feeding groups of vertically positioned boards into a transfer box which is pivoted to transfer the boards downwardly into board receiving mechanism including an elevator. The transfer box is provided with parallel walls which are relatively movable in accordance with the number and size of boards in a group. The board receiving mechanism comprises an extension of the parallel walls of the transfer box in their unloaded position, said board receiving mechanism having separator arms against which the side of a group of boards is received, and a gate extending downwardly in parallel juxtaposition to the separator arms, initially substantially closing off the board receiving mechanism. The gate further comprises a plurality of piston operated stops mounted for movement toward the separator arms for urging boards of a group into alignment.

Abstract: A sawmill apparatus includes first and second carriages for supporting first and second logging dogs therebeneath, with the second carriage being movable upon the first whereby to engage the ends of a log between the dogs. The carriages support the dogs at the end of steel baldes which are moved in a vertical direction by a combination of air cylinders and ball screws to provide the desired positioning of the log in a vertical direction. As the carriages urge the log between the blades of a bandsaw, rubber tired wheels are raised against the underside of the log for supporting cants or boards sawn therefrom and preventing splitting at the finally sawn edge.

Abstract: A cant or plank is moved forwardly on a conveyor system, where its irregular leading lateral edge is measured by a plurality of fixed scanners. In response to measurement of the cant, conveyor movement is altered for orienting the cant relative to a fixed saw line to be executed by a movable saw. The cant is held or clamped in stationary position while the saw is moved on a carriage relative thereto, resulting in severing of the undesired irregular forward edge. The sawn edge is employed as a reference as the cant is then moved forwardly on a conveyor system, where the measurements obtained from the scanners may be further utilized in cutting the cant into desired widths.

Abstract: A board separator apparatus for separating boards from groups of boards is described. The separator apparatus includes an input conveyor for feeding the groups of boards in a vertical position longitudinally into a transfer box, which is pivoted to transfer the boards onto an elevator member in the separation means. The elevator member lowers each group of boards into a separation position where they are held by a pressure plate against separator arms. The separator arms are moved outward into three different separator positions, thereby selectively causing three boards in a group to be moved one at a time off of the elevator into a separated condition. The separated boards slide down a ramp from the elevator member onto an output conveyor which transports the boards laterally away from the separator in a horizontal position. The boards are fed onto the output conveyor with the wane side of the boards facing up when such boards are cants cut from the side of a round log.