A lifting hook 100 (200, 250, 260, 270) has an inner leg 102, an outer leg 104, and a connecting part 106 connecting these legs. With respect to a worker equipped with a lever type carabiner 2(4), the inner leg 102 is located on the inner side close to the carabiner 2(4), and the outer leg 104 is located on the outer side far from the carabiner 2(4). The inner leg 102 and the outer leg 104 relatively have a height difference, and at least a portion 104main of the outer leg 104 is located higher than the inner leg 102.

A chain saw includes a connection rod and a front end assembly disposed at a front end of the connection rod. The front end assembly includes a motor, an output device, a transmission mechanism, and a front end casing. A ratio of rated output power P of the motor to a maximum weight of the chain saw is greater than or equal to 150 W/kg and less than or equal to 265 W/kg. The motor includes a rotor shaft, a rotor sleeve installed to the rotor shaft configured to rotate synchronously with the rotor shaft, a stator core disposed at least partially in the rotor sleeve, and a stator coil wound around the stator core.

A concrete cutting machine includes a motor, a pivot arm, and a concrete cutting chain assembly. The motor has an output drive, and the pivot arm has an input coupled to the output drive for receiving power from the motor. The arm is configured to pivot relative to the motor, and the pivot arm has a pivot arm output. The concrete cutting chain assembly is supported on the pivot arm and has a power input coupled to the pivot arm output. The chain assembly is configured to be pivotable relative to the pivot arm.

A method and apparatus for vertically felling of trees are provided by taking apart the trunk in a stepwise manner combining sagittal and horizontal cross-sections. A vertical frame is attachable to a tree trunk, the vertical frame having a movable portion and a fixed portion. A first cutting device is attachable to the vertical frame and configured to cut the tree sagittally substantially along a longitudinal axis of the tree. A second cutting device is attachable to the vertical frame and configured to cut the tree horizontally from an exterior of the tree to a sagittal cut made in the tree by the first cutting device. A locking mechanism releasably locks the movable portion of the frame to the fixed portion of the frame. The apparatus uses the weight of the upper trunk to maintain stability to steadily decrease the tree height until the entire tree is removed.

Disclosed is a portable, mechanical saw guide, system, and process for using the same. The saw guide includes a housing, boom, and finger member that creates a comparative measurement basis for cutting wood.

A saw mount for removably securing a saw to an object for cutting of the object includes: a base shaped to fit against a surface of the object; an arm extending from the base from a first end proximate to the base to a second end that is distal from the base; and a saw bracket pivotally mounted towards the distal end of the arm. The saw is removably secured to the saw bracket towards the distal end of the arm such that the saw pivots with respect to the base of the saw mount for cutting of the object by the saw.

Timber harvesting device, having an extension arm and a sawing unit and gripper unit attached to the extension arm. The gripper unit has a gripper pair for a tree trunk, and the sawing unit has a cutting element, e.g., a chain saw, which is arranged to be pivotable out of a saw box for severing the tree trunk. The saw box is pivotably arranged about a pivot axis on the gripper unit and is connected to the gripper unit via a spring element and a piston-cylinder unit. The spring element defines a predetermined cutting position of the saw box via a restoring torque about the pivot axis, and the saw box is pivotable by the piston-cylinder unit into an inclined position which is tilted relative to the cutting position. The bearing of the piston-cylinder unit has a free movement space in the cutting position of the saw box.

A method and apparatus are provided for vertically felling trees by taking apart the trunk in a stepwise manner combining sagittal and horizontal cross-sections. A vertical frame is attachable to a tree trunk, the vertical frame having a movable portion and a fixed portion. A first cutting device is attachable to the vertical frame and configured to cut the tree sagittally substantially along a longitudinal axis of the tree. A second cutting device is attachable to the vertical frame and configured to cut the tree horizontally from an exterior of the tree to a sagittal cut made in the tree by the first cutting device. A locking mechanism releasably locks the movable portion of the frame to the fixed portion of the frame. The apparatus uses the weight of the upper trunk to maintain stability to steadily decrease the tree height until the entire tree is removed.

An outdoor tool includes a powerhead, a tool unit powered by the powerhead, and a shaft assembly extending between the powerhead and the tool unit. The tool unit includes a transmission housing, a support plate, a guide bar adjustably supported by the support plate, a drive gear, and a chain circumscribing a portion of the drive gear and a portion of the guide bar, the drive gear operatively coupled to the powerhead. The tool unit further includes a tension adjustment mechanism for adjusting a position of the guide bar relative to the drive gear to increase and decrease a tension in the chain. The tension adjustment mechanism includes an adjustment screw, a threaded adjustment bolt, at least one adjustment gear, and a member coupled to the adjustment bolt and the guide bar. Rotation of the adjustment screw causes translation of the guide bar relative to the drive gear.

A tree limb or trunk cutter including a saw assembly, a clamp, and a remote controller. The saw assembly includes a housing, at least one motor disposed within the housing, and a saw bar support rotatably coupled to the housing. The motor is operatively coupled to the saw bar support and configured to rotate the saw bar support about an axis in a first direction and a second direction opposite the first direction. A wireless receiver coupled to the housing is operable to receive commands from a remote controller. The clamp is configured to secure to a limb or trunk of a tree. The housing releasably couples to the clamp. The remote controller is in communication with the wireless receiver and is configured to control a direction of rotation of the saw bar support and to control power provided to a chain drive.