Abstract: A drive coupler (102, 104) for coupling a reciprocating knife (106) to a drive member (112, 114) is provided, wherein the reciprocating knife (106) includes at least one elongate bar (120, 122, 180, 182) having a longitudinal extent and fixed to a plurality of blades (138), wherein the at least one elongate bar (120, 122, 180, 182) is supported on support members (140) that constrain the at least one elongate bar (120, 122, 180, 182) to reciprocate in a direction generally parallel to the longitudinal extent of the at least one elongate bar (120, 122, 180, 182), the drive coupler (102, 104) comprising: a first elongate strap (146, 162) configured to be attached to the at least one elongate bar (120, 122, 180, 182); a second elongate strap (146, 162) configured to be attached to the at least one elongate bar (120, 122, 180, 182); and an arrangement (152, 164, 187, 189, 193, 200) for (i) flexing the first elongate strap (146, 162) with respect to the second elongate strap (146, 162), (ii) for flexing the first

Abstract: A hinged row crop harvesting head (100) has two frame sections (110, 112, 114) coupled together with at least one hinge (186, 188) that permits the two frame sections (110, 112, 114) to pivot with respect to each other as the hinged row crop harvesting head (100) travels through a field harvesting crops.

Abstract: A double ended extendable driveshaft (106) comprises a first shaft portion (152, 154) that has a proximal end and a distal end; a first shaft coupler (110, 112) fixed to the distal end of the first shaft portion (152, 154); a first rotary coupler (160, 160?, 162) supported for rotation on the proximal end of the first shaft portion (152, 154); a second shaft portion (152, 154) having a proximal end and a distal end, wherein the proximal end of the second shaft portion (152, 154) is slidingly coupled to the proximal end of the first shaft portion (152, 154); a second shaft coupler (110, 112) fixed to the distal end of the second shaft portion (152, 154); a second rotary coupler (160, 160?, 162) supported for rotation on the proximal end of the second shaft portion (152, 154); and an actuator (158) coupled to the first rotary coupler (160, 160?, 162) and the second rotary coupler (160, 160?, 162) to extend and retract the first shaft portion (152, 154) with respect to the second shaft portion (152, 154).

Abstract: A drive coupler (102, 104) for coupling a reciprocating knife (106) to a drive member (112, 114) is provided, wherein the reciprocating knife (106) includes at least one elongate bar (120, 122, 180, 182) having a longitudinal extent and fixed to a plurality of blades (138), wherein the at least one elongate bar (120, 122, 180, 182) is supported on support members (140) that constrain the at least one elongate bar (120, 122, 180, 182) to reciprocate in a direction generally parallel to the longitudinal extent of the at least one elongate bar (120, 122, 180, 182), the drive coupler (102, 104) comprising: a first elongate strap (146, 162) configured to be attached to the at least one elongate bar (120, 122, 180, 182); a second elongate strap (146, 162) configured to be attached to the at least one elongate bar (120, 122, 180, 182); and a means (152, 164, 187, 189, 193, 200) for (i) flexing the first elongate strap (146, 162) with respect to the second elongate strap (146, 162), (ii) for flexing the first elongat

Abstract: A double ended extendable driveshaft (106) is provided comprising: a first shaft portion (152, 154) that has a proximal end and a distal end; a first shaft coupler (110, 112) fixed to the distal end of the first shaft portion (152, 154); a first rotary coupler (160, 160?, 162) supported for rotation on the proximal end of the first shaft portion (152, 154); a second shaft portion (152, 154) having a proximal end and a distal end, wherein the proximal end of the second shaft portion (152, 154) is slidingly coupled to the proximal end of the first shaft portion (152, 154); a second shaft coupler (110, 112) fixed to the distal end of the second shaft portion (152, 154); a second rotary coupler (160, 160, 162) supported for rotation on the proximal end of the second shaft portion (152, 154); and an actuator (158) coupled to the first rotary coupler (160, 160?, 162) and the second rotary coupler (160, 160?, 162) to extend and retract the first shaft portion (152, 154) with respect to the second shaft portion (152,

Abstract: A hinged row crop harvesting head (100) has two frame sections (110, 112, 114) coupled together with at least one hinge (186, 188) that permits the two frame sections (110, 112, 114) to pivot with respect to each other as the hinged row crop harvesting head (100) travels through a field harvesting crops.

Abstract: A feed drum for an agricultural harvesting head has fingers extending through the surface of the feed drum that translate laterally and generally parallel to the rotational axis of the feed drum as the feed drum rotates to compress the crop mat laterally inwardly toward a central axial portion of the feed drum.

Abstract: A controller for an electronically commutated electrical machine receives a feedback signal indicative of a parameter which it is desired to minimize, e.g. torque ripple, current, voltage, vibration or acoustic noise. The controller computes the amplitude and phase of a set of harmonics in the parameter and sequentially injects harmonics of the correct amplitude and phase to minimize the parameter. An optimizing routine iterates through the set of harmonics to further reduce the parameter.

Abstract: A controller for an electronically commutated electrical machine receives a feedback signal indicative of a parameter which it is desired to minimize, e.g. torque ripple, current, voltage, vibration or acoustic noise. The controller computes the amplitude and phase of a set of harmonics in the parameter and sequentially injects harmonics of the correct amplitude and phase to minimize the parameter. An optimizing routine iterates through the set of harmonics to further reduce the parameter.

Abstract: An electric stepper motor has in addition to the usual driving coils at least one additional coil wound on its stator and connected in a closed circuit. This additional coil damps any oscillations of the rotor. The closed circuit has a resistive value optimized to achieve maximum damping effect. Two or more such additional coils may be connected in a single closed circuit and a number of such closed circuits may be provided.

Abstract: A stepper motor has impedance in series with each drive coil and the value of the impedance is changed during each drive pulse. Two different paths for current to a drive coil may be provided each having a different value of impedance and the current to the drive coil is switched between the two paths during each drive period.