The present invention relates to cutting tools, in particular, to control systems for cutters such as vegetation cutters, especially hedge cutters or trimmers (10). Hedge cutters (10) frequently suffer in use from a problem of blocked cutting blades when they encounter a twig or branch whose size or density exceeds the capacity of the blades. We describe a vegetation cutting apparatus (10) having a plurality of cutting blades (11,12), at least one of which blades (11,12) is drivable by an electric motor. At least one driven blade (11,12) is movable between two predefined points of maximum travel. The apparatus (10) includes a control mechanism which causes a change of direction in the movement of the at least one movable blade at a point intermediate the points of maximum travel in response to an event sensed by the control mechanism.

The present invention relates to cutting tools, in particular, to control systems for cutters such as vegetation cutters, especially hedge cutters or trimmers (10). Hedge cutters (10) frequently suffer in use from a problem of blocked cutting blades when they encounter a twig or branch whose size or density exceeds the capacity of the blades. We describe a vegetation cutting apparatus (10) having a plurality of cutting blades (11,12), at least one of which blades (11,12) is drivable by an electric motor. At least one driven blade (11,12) is movable between two predefined points of maximum travel. The apparatus (10) includes a control mechanism which causes a change of direction in the movement of the at least one movable blade at a point intermediate the points of maximum travel in response to an event sensed by the control mechanism.

A side cutting unit for a cutting unit of an agricultural harvesting machine is disclosed. The side cutting unit comprises a support frame designed as a bar rail, wherein the bar rail supports, in the longitudinal direction, at least one oscillating knife bar using blade holding apparatuses, and at one end is coupled to a drive that causes the oscillating movement of the at least one knife bar, with the bar rail being designed as a one-piece profiled tube, such as an extruded profiled tube.

A system and method for performing cutting operations with an agricultural implement includes a cutting member capable of cutting plant material supported on the agricultural implement. A vibration source is operatively coupled to the cutting member. The vibration source is configured to generate a vibrational output at an ultrasonic frequency which is transmitted to the cutting member. The vibrational output is propagated through at least a portion of the cutting member to vibrate the cutting member as the plant material is being severed during the performance of the cutting operation.

A system and method for performing cutting operations with an agricultural implement includes a cutting member capable of cutting plant material supported on the agricultural implement. A vibration source is operatively coupled to the cutting member. The vibration source is configured to generate a vibrational output at an ultrasonic frequency which is transmitted to the cutting member. The vibrational output is propagated through at least a portion of the cutting member to vibrate the cutting member as the plant material is being severed during the performance of the cutting operation.

A header for an agricultural vehicle. The header includes a header frame and an elongate sickle knife mounted along a leading edge of the header. The header further includes an actuator for reciprocally moving the elongate sickle knife in its longitudinal direction relative to the header frame between a first position and a second position over an intermediate position. At least one accumulator extends between the header frame and the elongate sickle knife to accumulate energy during a first movement of the elongate sickle knife from the intermediate position towards at least one of the first position and the second position, and to release accumulated energy during a second movement of the elongate sickle knife opposite to the first movement.

A header for an agricultural vehicle. The header includes a header frame and an elongate sickle knife mounted along a leading edge of the header. The header further includes an actuator for reciprocally moving the elongate sickle knife in its longitudinal direction relative to the header frame between a first position and a second position over an intermediate position. At least one accumulator extends between the header frame and the elongate sickle knife to accumulate energy during a first movement of the elongate sickle knife from the intermediate position towards at least one of the first position and the second position, and to release accumulated energy during a second movement of the elongate sickle knife opposite to the first movement.

A system and method for performing cutting operations with an agricultural implement includes a cutting member capable of cutting plant material supported on the agricultural implement. A vibration source is operatively coupled to the cutting member. The vibration source is configured to generate a vibrational output at an ultrasonic frequency which is transmitted to the cutting member. The vibrational output is propagated through at least a portion of the cutting member to vibrate the cutting member as the plant material is being severed during the performance of the cutting operation.

A system and method for performing cutting operations with an agricultural implement includes a cutting member capable of cutting plant material supported on the agricultural implement. A vibration source is operatively coupled to the cutting member. The vibration source is configured to generate a vibrational output at an ultrasonic frequency which is transmitted to the cutting member. The vibrational output is propagated through at least a portion of the cutting member to vibrate the cutting member as the plant material is being severed during the performance of the cutting operation.

A reciprocating power tool comprising a first blade and a second blade, wherein the first blade is driven by a first shaft assembly, wherein the second blade is driven by a second shaft assembly, wherein the first and second blade assemblies are reciprocally driven by a cam shaft, wherein the first shaft assembly defines a first moment of inertia, wherein the second shaft assembly defines a second moment of inertia, and wherein the first and second moments of inertia are within 5% of one another.