Machine for making unitized stacks of bags

Claim 1

In a machine for making a unitized stack of vest type bags from a tubular web of plastic film comprising, essentially, a horizontal frame, adjoining one of the extremities of which is a unit for unwinding the plastic film, the frame supporting, at the intermediate portion, means comprising transverse rollers for pulling the plastic film and cutting means for cutting the film to define straps and a joining area of the bags, and a sealing and cutter unit being provided at the opposite extremity of said frame to effect transverse seals for closing the bottom and interconnecting the straps of bags being formed in adjacent sections of the plastic film, and to effect transverse cuts for separating adjacent bags and, at the outlet of said sealing and cutter unit, there being provided a bundling and ejector unit for joining a plurality of bags to form a block and for ejecting the then finished block, the improvement comprising the bundling and ejector unit (6) having a sealing table (7), made up by a length of stock with an inverted "U" section, seated fixedly and transversely on the frame (1) and interposed between a tilting vane (8) and a tilting table (9), said length of "U"-section stock having a section thereof provided with a groove (10), adjoining which are lateral and external rubber seats (11) and through which extend one or more sealing electrodes in the shape of pins (12) that perform the joining of the plurality of bags making up a block and alongside of which are needles (13) to stabilize the bags on the sealing table (7), both sealing electrodes (12) and needles (13) being seated on a support (14) for moving upwards or downwards to apply or to withdraw said electrodes (12) and needles (13) from said groove (10) on the sealing table (7) and there being, above the latter, a corresponding depressing bar (15) formed by a length of stock with a rectangular section with the surface thereof facing the sealing table (7) being provided with a longitudinal groove (16) corresponding to groove (10) on the latter and adjoining which an external rubber seat (17) is also provided, said depressing bar (15) moving vertically for urging the plastic film (2) against the sealing electrodes (12) and stabilizing needles (13) and upon which a duct (18) is seated with a plurality of air-emitting nozzles (19) being turned toward the tilting vane (8) and which act in cooperation with the latter, the tilting vane (8) being interposed between the sealing table (7) and the sealing and cutter unit (5), whereas the tilting table (9) is interposed between the referenced sealing table (7) and a support carrier (20), the tilting vane (8) being in a horizontal position for, supporting the plastic film (2) in the displacement thereof from the sealing and cutter unit (5) to the table (7) and moving to a vertical position for extracting a finished bag from the sealing and cutter unit (5), which finished bag is extracted from above the tilting vane (8) by jets of air coming from the air-emitting nozzles (19), with the tilting table (9) being positioned slantingly and downwardly relative to the sealing table (7) and for supporting a block being formed and moving angularly for throwing a then formed block onto the support (20).