A saw apparatus includes a guide bar, a chain driver, and an endless cutting chain trained about the guide bar and the chain driver. The guide bar includes a first chain retention feature along at least a portion of its periphery, and the cutting chain includes a second chain retention feature configured to interact with the first chain retention feature such that movement of the second chain retention feature away from the guide bar is restricted. A timber-working device includes a frame, at least one pair of arms pivotally attached to the frame and configured to be controlled to grasp at least one tree, and the saw apparatus mounted to the frame.

The disclosed technology generally regards a chainsaw guard mountable on a chainsaw having a motor powerhead housing, a drive motor contained in the housing, a saw chain guide bar mounted on the housing, and a saw cutter chain driven by the drive motor and carried on the saw chain guide bar, the chainsaw guard forming a physical barrier that limits access to the saw cutter chain when the chainsaw guard is mounted on the powerhead housing. The chainsaw guard includes a bracket member mountable to a chainsaw motor powerhead housing, and a retractable member movably engaged with the bracket member and designed and configured to sheathe the saw chain guide bar and saw cutter chain of the chainsaw when the chainsaw guard is mounted on a chainsaw. Engaged with the bracket member and the retractable member are compressible springs about one or more guide rods, the springs having a spring force to position the retractable member relative to the bracket member in the extended position until a force greater than the spring force is applied to the distal end of the retractable member, translating the retractable member towards the retracted position; when the force is removed from the distal end of the retractable member, the retractable member by the spring force moves to the extended position.

Examples herein include a chainsaw bar shield and a method for using a chainsaw bar shield. A chainsaw bar shield comprises a bar shield arm extending from at least one securing mechanism for engaging and pinching a chainsaw bar extending from a chainsaw housing. The securing mechanism offsets the bar shield arm from a chainsaw chain extending from the chainsaw housing and, thereby, protects a user by separating the user from the chainsaw chain during maintenance of a chainsaw. Other examples of a chainsaw bar shield comprise an enclosure secured to a chainsaw bar which is offset from and substantially encloses a chainsaw chain extending from a chainsaw housing.

The disclosed technology generally regards a chainsaw guard mountable on a chainsaw having a motor powerhead housing, a drive motor contained in the housing, a saw chain guide bar mounted on the housing, and a saw cutter chain driven by the drive motor and carried on the saw chain guide bar, the chainsaw guard forming a physical barrier that limits access to the saw cutter chain when the chainsaw guard is mounted on the powerhead housing. The chainsaw guard includes a bracket member mountable to a chainsaw motor powerhead housing, and a retractable member movably engaged with the bracket member and designed and configured to sheathe the saw chain guide bar and saw cutter chain of the chainsaw when the chainsaw guard is mounted on a chainsaw. Engaged with the bracket member and the retractable member are compressible springs about one or more guide rods, the springs having a spring force to position the retractable member relative to the bracket member in the extended position until a force greater than the spring force is applied to the distal end of the retractable member, translating the retractable member towards the retracted position; when the force is removed from the distal end of the retractable member, the retractable member by the spring force moves to the extended position.

A power tool includes a switch moveable between a first position enabling activation of a motor and a second position disabling the motor. The power tool includes a trigger movably coupled to a housing of the power tool between an OFF position and an ON position. The switch moves from the second position to the first position in response to the trigger moving from the OFF position to the ON position. The power tool includes a trigger lock-off pivotably coupled to the housing between a lock position and an unlock position. The trigger lock-off is engageable with the trigger to inhibit movement of the trigger from the OFF position to the ON position when the trigger lock-off is in the lock position. The trigger lock-off allows movement of the trigger from the OFF position to the ON position when the trigger lock-off is in the unlock position.

Examples herein include a chainsaw bar shield and a method for using a chainsaw bar shield. A chainsaw bar shield comprises a bar shield arm extending from at least one securing mechanism for engaging and pinching a chainsaw bar extending from a chainsaw housing. The securing mechanism offsets the bar shield arm from a chainsaw chain extending from the chainsaw housing and, thereby, protects a user by separating the user from the chainsaw chain during maintenance of a chainsaw. Other examples of a chainsaw bar shield comprise an enclosure secured to a chainsaw bar which is offset from and substantially encloses a chainsaw chain extending from a chainsaw housing.

Systems and methods for a chainsaw safety device are described. In some embodiments, a method comprises activating a chainsaw, receiving a first acceleration value associated with acceleration of the chainsaw, comparing the first acceleration value to a predetermined acceleration threshold, and deactivating the chainsaw based on the comparison.

A chainsaw includes a handle with a handgrip; an electric motor for endlessly moving a saw chain; a control unit for controlling rotation of the motor; and a main power switch switchable between an ON state and an OFF state. The handgrip is provided with a gripping detection device for detecting whether the handgrip is gripped by the worker, and the chainsaw is configured to, when the control unit is manipulated to deactivate the electric motor in a state in which the gripping detection device detects that the handgrip is gripped, maintain the main power switch in the ON state, and to, when the control unit is manipulated to deactivate the electric motor in a state in which the gripping detection device detects that the handgrip is not gripped, switch the main power switch to the OFF state.

A power tool includes a switch moveable between a first position enabling activation of a motor and a second position disabling the motor. The power tool includes a trigger movably coupled to a housing of the power tool between an OFF position and an ON position. The switch moves from the second position to the first position in response to the trigger moving from the OFF position to the ON position. The power tool includes a trigger lock-off pivotably coupled to the housing between a lock position and an unlock position. The trigger lock-off is engageable with the trigger to inhibit movement of the trigger from the OFF position to the ON position when the trigger lock-off is in the lock position. The trigger lock-off allows movement of the trigger from the OFF position to the ON position when the trigger lock-off is in the unlock position.

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.