A wood chipper includes an engine and a chipper structure (e.g., a chipper disc or a chipper drum). A drive assembly is disposed between the engine and the chipper structure. The drive assembly comprises at least one pulley. The at least one pulley defines a cylindrical recess therein. A drum brake assembly is configured to engage the cylindrical recess of the at least one pulley.

A tooth (2) for use in a grinding wheel (4), the tooth (2) including a spigot (8) for cooperating with a corresponding structure within a slot (10) of the grinding wheel (4) and a bolt (14) for locking the tooth (2) in the slot (10) of the wheel (4), and a grinding wheel (4) comprising the tooth (2).

A tractor attachment for stump grinding has an attachment body, which has at least a shield opening, a hydraulic motor opening, and a pulley opening that are disposed through the tractor attachment. An attachment arm is coupled to the tractor attachment. A shield is removably mounted over a portion of the shield opening. A grinder with a grinder blade and a grinder pulley are mounted on an underside of the attachment body. A hydraulic motor with a hydraulic motor pulley is mounted through the hydraulic motor opening. At least one belt is rotatably disposed between the hydraulic motor pulley and the grinder pulley. The attachment arm is configured to be attached to a boom attachment on a tractor boom.

A rotatable cutter wheel of a material reduction machine, the cutter wheel including a drive plate configured to be mounted on the material reduction machine for rotation in a forward rotation direction about a central axis. The drive plate includes a central driveshaft aperture and an outer peripheral edge. A wear plate is positioned along a first axial side of the drive plate and removably coupled to the drive plate. A cutter is removably coupled for rotation with the drive plate via a fastener. A wear insert is positioned to cover a portion of the outer peripheral edge of the drive plate, the wear insert being mounted to the wear plate and held in spaced relation to the outer peripheral edge of the drive plate.

A stump cutter includes a cutter wheel rotatable about a cutter wheel axis, the cutter wheel supported by a boom for sweep movements about a vertical cutter wheel sweep axis, and the cutter wheel is supported by the boom for tilt movements about a horizontal cutter wheel tilt axis. A prime mover is configured to drive the cutter wheel about the cutter wheel axis. A mechanical driveline provides power transmission from the prime mover to the cutter wheel, the mechanical driveline including a final drive cutter wheel gearbox positioned along the cutter wheel axis, and a swivel gearbox assembly including two right angle gearboxes joined with a swivel joint therebetween. The swivel joint between the two right angle gearboxes forms a driveline swivel axis. A downstream one of the two right angle gearboxes includes an output shaft connected to an input shaft of the final drive cutter wheel gearbox.

A stump cutter includes a mainframe and a cutter wheel supported by a boom and rotatable about a cutter wheel axis spaced from the mainframe. A two-axis gimbal set supports the boom from the mainframe, the two-axis gimbal set supporting the boom for sweep movements of the cutter wheel about a vertical cutter wheel sweep axis and for tilt movements of the cutter wheel about a horizontal cutter wheel tilt axis. A prime mover on the mainframe is configured to drive the cutter wheel about the cutter wheel axis. A mechanical driveline is configured to provide power transmission from the prime mover to the cutter wheel, the mechanical driveline including a constant velocity joint.

A stump grinder chip pickup chute device and collection system structured and/or configured to capture and control chips cut from a stump by a stump grinding/cutting wheel and to redirect the chips to a desired target chip collection location.

Embodiments in this disclosure include a cutting tool mounting block that is securely mounted to the periphery of a wheel. The mounting block includes a body portion with a channel having a width that expands along the length of the body portion. The cutting tool mounting block also includes an aperture configured to accept a single cutting tooth, in some embodiments. The cutting tool mounting block may also include a front feature that creates a clearance between the cutting tooth surface and the body portion. Some embodiments include the assembly of three mounting blocks on a stump grinder wheel, which can increases the bite each tooth takes, it can decrease the drag in the cutting wheel, and it can decrease chip recirculation.

A material reduction machine includes a prime mover driving a cutting mechanism. A drive system receives a signal to initiate rotation of a cutting mechanism. A sensor senses a machine load parameter and reports a signal to a controller operatively coupled to the clutch to control sequential engagement cycles from the engine to the cutting mechanism. The controller utilizes a stored first disengagement threshold value for stopping a first engagement cycle and continues monitoring the signal as the machine load parameter increases momentarily after reaching the first disengagement threshold. The controller determines and adopts a second disengagement threshold value based on observation of the machine load parameter indicative of maximum load during the continued monitoring after the first disengagement threshold is realized, and further being based on a stored correction factor. The second disengagement threshold value is used for a second engagement cycle.

Embodiments of an apparatus for reducing plant material are disclosed. In one embodiment, the apparatus includes a frame, a boom coupled to and extending from the frame, a drive assembly at least partially coupled to the boom and having a drive shaft rotatable relative to the boom, a hub interconnected to and rotatable with the drive shaft, a cutting wheel interconnected to and rotatable with the hub, and a shearing device coupled to the boom and having a working surface adjacent the hub. The working surface at least partially defines a shearing feature for shearing material wrapped around the hub as the hub rotates.