Roller drive unit

A roller drive unit for the drive of articles (100) movable on a conveyor track and comprising:

• at least one drive roller (1;
• 1, 1') carried by a drive shaft (10);
• a motor (3;
• 403);
• at least one gear arrangement (50, 60, 61;
• 460 to 463);
• guide equipment (40;
• 440, 440');
• and control equipment;
• said drive roller (1;
• 1, 1') being rotationally drivable by said motor (3;
• 403) through said gear arrangement (50, 60, 61;
• 460 to 463) which transmits driving torque from said motor to said drive roller;
• said drive shaft (10) being rotationally mounted in said guide equipment (40;
• 440, 440') such that said drive roller (1;
• 1, 1') is pivotable with respect to a base on a circularly arcuate movement path;
• said drive roller (1;
• 1, 1') being movable by means of said control equipment (40;
• 440, 440') along said circularly arcuate movement path between a lower rest position and an upper drive position in which latter position said drive roller (1;
• 1, 1') stands in engagement with the underside of said article (100) to be driven;
• wherein said control equipment comprises a clutch device (30;
• 430) designed for the transmission of a torque between said gear arrangement (50, 60, 61;
• 460 to 463) in such a manner that the value of said transmitted torque can be greater than the driving torque required for the raising of the drive roller (1;
• 1, 1') into said upper drive position;
• wherein said gear arrangement (50, 60, 61, 460 to 463) includes a first gear wheel (60;
• 460), which is borne on a shaft (20;
• 420) and is driven by the motor (3;
• 403), and a second gear wheel (61;
• 461) which is driven in the opposite sense by said first gear wheel and is mounted secure against rotation to said drive shaft (10) of said drive roller (1;
• 1, 1');
• characterized in that
• said shaft (20;
• 420) of said first gear wheel (60;
• 460) is rotatably borne in fixed location relative to said base;
• and on that
• said circularly arcuate movement path of said drive roller (1;
• 1, 1'), which path is defined by said guide equipment (40;
• 440, 440'), is defined to be arranged concentrically with the rotational axis of said shaft (20;
• 420) of said first gear wheel.