Abstract: A timber-working device comprises a frame having a feed axis and a drive system configured to feed at least one stem along the feed axis. The drive system comprises a first drive arm pivotally attached to the frame on a first side of the feed axis, having a first rotary drive having a first wheel. A second drive arm is also pivotally attached to the frame on a second side of the feed axis, having a second rotary drive having a second wheel. The drive system also comprises a third rotary drive having a third wheel, and a fourth rotary drive having a fourth wheel, mounted on the frame on the first and second sides of the feed axis respectively. At least one processor controls operation of the rotary drives, such that in a first mode the speed of the respective wheels of the rotary drives on the same side of the feed axis is substantially the same, and in a second mode the speed of the respective wheels of at least two rotary drives on opposing sides is substantially the same.

Abstract: A timber-working device having a first pivoting drive arm and a second pivoting drive arm, and a timing link for connecting them. The timing link includes an elongate member having a first end and a second end. A first aperture is at the first end and a second aperture at the second end. At least one of the first aperture and the second aperture is elongate along the length of the member.

Abstract: A timber-working device having a first pivoting drive arm and a second pivoting drive arm, and a timing link for connecting them. The timing link includes an elongate member having a first end and a second end. A first aperture is at the first end and a second aperture at the second end. At least one of the first aperture and the second aperture is elongate along the length of the member.

Abstract: A timber-working device has a frame, including a feed axis having first and second sides. A drive system independently feeds stems along the feed axis, and has a first rotary drive having a first wheel acting against a first stem on the first side, and a second rotary drive having a second wheel acting against a second stem on the second side. The device has at least two distance measurement devices, each side of the feed axis having an associated distance measurement device. Each generates measurement signals indicative of the length of stems fed along the feed axis, at least one of them indicative of rotation of one of the rotary drives. A processor receives the respective measurement signals, and for each of the first and second stems, determines the length of at least a portion of the stem fed by the drive system based at least in part on the respective measurement signals.

Abstract: A timber-working device comprises a frame having a feed axis and a drive system configured to feed at least one stem along the feed axis. The drive system comprises a first drive arm pivotally attached to the frame on a first side of the feed axis, having a first rotary drive having a first wheel. A second drive arm is also pivotally attached to the frame on a second side of the feed axis, having a second rotary drive having a second wheel. The drive system also comprises a third rotary drive having a third wheel, and a fourth rotary drive having a fourth wheel, mounted on the frame on the first and second sides of the feed axis respectively. At least one processor controls operation of the rotary drives, such that in a first mode the speed of the respective wheels of the rotary drives on the same side of the feed axis is substantially the same, and in a second mode the speed of the respective wheels of at least two rotary drives on opposing sides is substantially the same.

Abstract: A tree harvester head comprises a drive wheel, a delimb knife, a pin, a wheel-mounting inner sleeve to which the drive wheel is mounted, and a knife-mounting outer sleeve to which the delimb knife is mounted. The wheel-mounting inner sleeve surrounds the pin for rotation of the wheel-mounting inner sleeve and the drive wheel mounted thereto about the pin. The knife-mounting outer sleeve surrounds the wheel-mounting inner sleeve for relative rotation therebetween for rotation of the delimb knife about the pin.

Abstract: A tree harvester head comprises a drive wheel, a delimb knife, a pin, a wheel-mounting inner sleeve to which the drive wheel is mounted, and a knife-mounting outer sleeve to which the delimb knife is mounted. The wheel-mounting inner sleeve surrounds the pin for rotation of the wheel-mounting inner sleeve and the drive wheel mounted thereto about the pin. The knife-mounting outer sleeve surrounds the wheel-mounting inner sleeve for relative rotation therebetween for rotation of the delimb knife about the pin.