A chainsaw having a drive motor. The chainsaw has a fixed part and a movable part. The guide bar is retained on the fixed part in a manner braced between the fixed part and a tensioning element. The movable part is shiftable in a longitudinal direction with respect to the fixed part in order to tension the saw chain with the tensioning element released. The chainsaw has a stop face and a tensioning face. At least one additional contact face that is firmly connected to the fixed part in the longitudinal direction and at least one additional contact face that is firmly connected to the movable part in the longitudinal direction are arranged between the stop face and the tensioning face. All the contact faces lie one after another in the flux of force from the tensioning element to the fixed part.

A sawmill feedspeed control system having a force sensor operatively coupled to a sawguide of a sawblade, the output of the force sensor being processed and supplied to a motion controller and driver for reducing or increasing feed velocity of a workpiece so as to prevent overfeed or underfeed, while minimizing deviations of the blade from a straight cut and maximizing production throughput.

A chainsaw having a drive motor. The chainsaw has a fixed part and a movable part. The guide bar is retained on the fixed part in a manner braced between the fixed part and a tensioning element. The movable part is shiftable in a longitudinal direction with respect to the fixed part in order to tension the saw chain with the tensioning element released. The chainsaw has a stop face and a tensioning face. At least one additional contact face that is firmly connected to the fixed part in the longitudinal direction and at least one additional contact face that is firmly connected to the movable part in the longitudinal direction are arranged between the stop face and the tensioning face. All the contact faces lie one after another in the flux of force from the tensioning element to the fixed part.

A device for deflecting a detached cutting chain off the drive sprocket of a chain saw in order to deenergize and arrest it. A ramp provides a surface disposed below the chain guide bar, which surface is oblique with respect to the chain guide bar, slightly below a lower edge of the chain guide bar and obliquely angled with respect to a plane that contains the exterior surface of the chain guide bar, and distal to the drive sprocket. Sliding engagement of a detached cutting chain with the oblique surface moves the cutting chain exteriorly away from the chain guide bar and off the drive sprocket. A chain catcher is also provided to arrest the detached cutting chain and/or chain shot portions thereof.

An apparatus for automatically adjusting a chainsaw cutting element as the chainsaw cutting element lengthens during use due to thermal expansion includes an elongate flat bar circumscribed by the chainsaw cutting element, a motor for causing the chainsaw cutting element to rotate about the elongate flat bar, a motor housing for housing the motor and a cover housing secured to the motor housing for covering a proximal end of the elongate flat bar and a rotatably mounted sprocket gear that engages a proximal end of the chainsaw cutting element. The elongate flat bar has a first, fully retracted position, a second, fully extended position, and an infinite number of positions of adjustment therebetween. Bias members continuously urge the elongate flat bar to displace during saw operation in a proximal-to-distal direction from the first, fully retracted position to the second, fully extended position to maintain chain tension at all times.

A bandsaw assembly for cutting large diameter workpieces such as turbine rotors, heat exchangers or shafts at a plant or factory and a method of using the same is disclosed. The assembly includes a frame; ground-engaging wheels or a track provided on the frame; a plurality of spaced apart towers extending vertically upwardly from the frame; a rotatable drive wheel mounted on each tower, said drive wheel being horizontally oriented and presenting a vertically oriented circumferential surface; a motor operatively engaged with one or more of the drive wheels; and a bandsaw blade passing around the wheels and being in contact with the circumferential surfaces thereof; said blade being selectively driven by the drive wheels. The towers are variable in length to raise or lower the blade. The assembly is reduced in width for transportation or storage and increased in width for operation.