Abstract: A brake (26) employed to control web tension on a roll stand (10) is provided as a generator whose rotor shaft (38) is mounted on the roll stand's core-coupler spindle (16). The rotor (36) may be journaled in the generator's stator assembly (52) so that the spindle (16) supports the entire generator, and alignment problems that might otherwise require complicated flexible couplings, and excessive axial protrusion of the generator into service aisles are avoided. In another version, the generator stator (52) is mounted directly on the roll stand's arm (12) so that generator rotor-stator alignment is set by the journaling of the spindle (16) in the arm (12). Accurate web tension results from current feedback for control of the generator load.

Abstract: A windpower system includes a support and a turbine having a shaft rotatively mounted to the support. The turbine has variable pitch blades whose pitch is controlled by the differential motion of a rotary control shaft coaxial with the turbine shaft and the turbine shaft itself so that the blade pitch can be varied by a stationary motor without requiring any slip rings or other such wear-prone couplings. In the event of a power failure, rotary motion of the control shaft is prevented so that the turbine blades are feathered solely due to the force developed by the rotating turbine. Also, if the turbine is used to generate electrical power, an induction generator coupled to the turbine shaft is employed whose shaft speed is indicative of generator output power.

Abstract: In order to control the turbine speed of a windmill employed for power generation, the pitch of the turbine blades is based on a dual-deadband control strategy. If the current turbine speed is determined to be outside of a relatively wide deadband, action is taken to correct the speed by changing blade pitch accordingly. If the current speed is not outside of the relatively wide deadband, then the average of the turbine speed over a recent interval is compared with a relatively narrow deadband within the wider deadband. Action is then taken to change the blade pitch if the average speed is outside the narrow deadband. In this way, wide excursions of turbine speed are corrected promptly, but the frequency of control actions is minimized by requiring only the average speed to be kept within tight limits.

Abstract: Disclosed is a document printer of the type suitable for imprinting messages upon individual documents fed into the apparatus (e.g., bank checks). The apparatus includes an internal printing station disposed along a document feed path. The path includes a feed slot in an exterior wall of the apparatus. The printing station includes both impact printer means and document drive means, the latter operative to move the document along the document path positioning different parts of the document adjacent the impact printer means for the printing of multiple lines of information, where necessary. Both the impact printer means and the document drive means comprise first and second subunits which are positioned, respectively, on opposite sides of a document at the printing station. In particular, the drive means comprise upper and lower rollers, at least one of which is driven, which are engagable with opposite surfaces of the document.