A powered threaded rod cutter includes first and second cutting dies, an electric motor, a planetary transmission positioned downstream of the motor, a drivetrain for converting a rotational output of the transmission to a pivoting movement of the first cutting die, and a clutch mechanism for redirecting torque from the motor away from a drivetrain and the first cutting die in response to the first cutting die seizing during a rod-cutting operation. The clutch mechanism includes a ring gear in the planetary transmission, and a spring that rotationally affixes the ring gear below a predetermined threshold of reaction torque through the drivetrain and permits rotation of the ring gear above the threshold.

A powered threaded rod cutter includes first and second cutting dies, an electric motor, a planetary transmission positioned downstream of the motor, a drivetrain for converting a rotational output of the transmission to a pivoting movement of the first cutting die, and a clutch mechanism for redirecting torque from the motor away from a drivetrain and the first cutting die in response to the first cutting die seizing during a rod-cutting operation. The clutch mechanism includes a ring gear in the planetary transmission, and a spring that rotationally affixes the ring gear below a predetermined threshold of reaction torque through the drivetrain and permits rotation of the ring gear above the threshold.

A tree saw attachment for a modular landscape trimmer is disclosed. In one embodiment, the tree saw attachment is provided with a drive unit having a drive shaft operably connectable to a motive source and a transmission operably connected to the drive shaft. An anvil is connected to and extending from an output side of the transmission of the drive unit, and a blade is connected to the output shaft of the transmission. The blade has an arcuate outer peripheral edge with teeth formed along a portion thereof forming a cutting edge so as the output shaft is rotated, the distance between the cutting edge and a central axis of the output shaft increases until the blade has substantially completed one rotation. Rotation of the blade causes the blade to move transversely with respect to the anvil to engage and cut material positioned between the blade and the anvil.

A tree saw attachment for a modular landscape trimmer is disclosed. In one embodiment, the tree saw attachment is provided with a drive unit having a drive shaft operably connectable to a motive source and a transmission operably connected to the drive shaft. An anvil is connected to and extending from an output side of the transmission of the drive unit, and a blade is connected to the output shaft of the transmission. The blade has an arcuate outer peripheral edge with teeth formed along a portion thereof forming a cutting edge so as the output shaft is rotated, the distance between the cutting edge and a central axis of the output shaft increases until the blade has substantially completed one rotation. Rotation of the blade causes the blade to move transversely with respect to the anvil to engage and cut material positioned between the blade and the anvil.

A hand tool with a mechanical linear drive mechanism coupled to a linear activated working implement. The drive mechanism includes a geared planetary roller screw that includes a torque tube connected to a roller screw's nut body. The planetary roller screw includes a fixed outer race, a rotating set of grooved rollers axially aligned inside the outer race, a cylindrical nut body located inside the set of grooved roller, a plurality of inner rollers axially aligned and inside the nut body, a threaded shaft axially aligned and inside the inner rollers, and a torque tube axially aligned inside the inner rollers. The torque tube is connected at one end to a gear box which is coupled to an electric motor. When the electric motor is activated, the torque tube is rotated which causes a threaded shaft in the tool to move axially. A working implement is coupled to the distal end of the threaded shaft.

A hand tool with a mechanical linear drive mechanism coupled to a linear activated working implement. The drive mechanism includes a geared planetary roller screw that includes a torque tube connected to a roller screw's nut body. The planetary roller screw includes a fixed outer race, a rotating set of grooved rollers axially aligned inside the outer race, a cylindrical nut body located inside the set of grooved roller, a plurality of inner rollers axially aligned and inside the nut body, a threaded shaft axially aligned and inside the inner rollers, and a torque tube axially aligned inside the inner rollers. The torque tube is connected at one end to a gear box which is coupled to an electric motor. When the electric motor is activated, the torque tube is rotated which causes a threaded shaft in the tool to move axially. A working implement is coupled to the distal end of the threaded shaft.

A hand tool with a mechanical linear drive mechanism coupled to a linear activated working implement. The drive mechanism includes a roller screw that includes a torque tube connected to a roller screw's nut body. The roller screw includes a fixed outer race, a rotating set of grooved rollers axially aligned inside the outer race, a cylindrical nut body located inside the set of grooved roller, a plurality of inner rollers axially aligned and inside the nut body, a threaded shaft axially aligned and inside the inner rollers, and a torque tube axially aligned inside the inner rollers. The torque tube is connected at one end to a multiple speed gear box which includes a primary motor coupled to a earner gear with three planet gears. Disposed around the planet gears is a ring gear. Coupled to the ring gear is a secondary motor which when activated causes the ring gear to rotate in the opposite direction of the planet gears. At least one sensor measures the rotation of an elastomeric ring and control activation of the secondary motor to change the operational speed of the tool.

A hand tool with a mechanical linear drive mechanism coupled to a linear activated working implement. The drive mechanism includes a roller screw that includes a torque tube connected to a roller screw's nut body. The roller screw includes a fixed outer race, a rotating set of grooved rollers axially aligned inside the outer race, a cylindrical nut body located inside the set of grooved roller, a plurality of inner rollers axially aligned and inside the nut body, a threaded shaft axially aligned and inside the inner rollers, and a torque tube axially aligned inside the inner rollers. The torque tube is connected at one end to a multiple speed gear box which includes a primary motor coupled to a earner gear with three planet gears. Disposed around the planet gears is a ring gear. Coupled to the ring gear is a secondary motor which when activated causes the ring gear to rotate in the opposite direction of the planet gears. At least one sensor measures the rotation of an elastomeric ring and control activation of the secondary motor to change the operational speed of the tool.

A powered shearing mechanism or cutter is disclosed that comprises an asynchronous double class 1 lever and a linear actuator that uses two ganged wheels to pry the effort portion of both levers open and close the jaws. The wheels move linearly—with the distance between them kept constant—and roll along—and exert force against—parts of the levers called “bearing surfaces.” The bearing surfaces are non-planar and reflectively symmetric and their profile is customized to provide any desired ideal mechanical advantage for the cutter. In accordance with the illustrative embodiment, the profile of the bearing surfaces is a circular arc, which provides a bearing surface which is easy to precisely fabricate and that provides a fairly constant ideal mechanical advantage at each point as the cutter's blades cut through the material.

A powered shearing mechanism or cutter is disclosed that comprises an asynchronous double class 1 lever and a linear actuator that uses two ganged wheels to pry the effort portion of both levers open and close the jaws. The wheels move linearly—with the distance between them kept constant—and roll along—and exert force against—parts of the levers called “bearing surfaces.” The bearing surfaces are non-planar and reflectively symmetric and their profile is customized to provide any desired ideal mechanical advantage for the cutter. In accordance with the illustrative embodiment, the profile of the bearing surfaces is a circular arc, which provides a bearing surface which is easy to precisely fabricate and that provides a fairly constant ideal mechanical advantage at each point as the cutter's blades cut through the material.