Transfer unit for transferring articles between two lines angularly disposed to each other

A transfer unit for transferring articles, comprising:

• a first line, along which the articles are made to advance according to a first orientation;
• a second line, perpendicular to the first line and along which the articles are made to advance according to a second orientation, rotated in the horizontal plane relative to the first orientation;
• a rotary carousel including a set of pickup devices circumferentially distributed around the rotary carousel and driven to pick up the articles one after the other from the first line and, after rotating the rotary carousel through a predetermined circular arc, to place the articles on the second line, the rotary carousel being rotatable about a vertical axis, the pickup devices including engagement surfaces respectively for engaging the articles;
• arms respectively mounting the pickup devices to the rotary carousel, the arms being rotatably supported around a respective middle circle having an axis parallel to vertical axis of the rotary carousel, the pickup devices being driven in counter-rotation and in phase relationship with a rotation direction of the rotary carousel, such that, as the rotary carousel rotates, the pickup devices are made to move along an elliptic trajectory, and the pickup devices are in turn driven in counter-rotation relative to the respective arms such that an orientation of the pickup devices, and hence that of the articles transferred, remains constant in the horizontal plane while respective free ends of the arms rotate at the first line and the second line;
• a pair of plates fixedly spaced from each other and between which are located:
• a fixed supporting structure;
• a movable supporting structure including the rotary carousel, the movable supporting structure rotatably associated with the fixed supporting structure and drivable in rotation;
• wherein the rotary carousel includes:
• a base plate at a bottom of the rotary carousel;
• tubular supports mounted to the base plate and having bottom ends supporting the arms respectively;
• a set of stems mounted vertically, protruding from the base plate and fitted rotatably on the tubular supports respectively;
• a cam drum which is held fixed relative to the rotation of the rotary carousel and acting on the top ends of the stems to cause the stems to be lowered when the pickup devices are to be moved close to the first line to pick up articles to be transferred and then to be raised and lowered again to place the articles on the second line;
• a crown wheel coaxial with and fixed to the rotary carousel;
• gears respectively keyed to the tubular supports;
• a set of idler gears engaging the crown wheel and the gears such that the rotation of the rotary carousel causes counter-rotation of the tubular supports, and hence of the respective arms, relative to the rotation direction of the rotary carousel;
• a set of sealed circular chambers made in the base plate and concentric with respective axes of rotation of the tubular supports fitted around the stems, the circular chambers being open at bottoms thereof and containing respective bushings which are sealingly and rotatably inserted therein, the respective bushings supporting the tubular supports, the circular chambers being connected to a source of negative suction pressure;
• internal holes made in the arms respectively and connected to the pickup devices respectively;
• ducts including free ends inserted slidably into the internal holes respectively and connected between the pickup devices and the circular chambers respectively to activate a negative suction pressure at the pickup devices for picking up and holding the articles.