Patent ID: 6308497
Filing Date: 2001-10-30
Classification: B65B

Abstract:
An apparatus for driving folders having reciprocating motion of variable amplitude in machines for packaging or wrapping products with a sheet of flexible material, said machines comprising:a conveyor with housings of adjustable size into which the product is cyclically inserted with an overlying packaging sheet, the lower flaps of which sheets are subsequently folded and overlapped by a pair of folders which run on parallel guides, and wherein one of the folders is connected to the lower run and the other to the upper run of a pair of parallel synchronized conveyors, one of the folders being hinged to parallel and identical rods which in turn are hinged to parallel and identical cranks keyed to a common shaft which is driven by an electric motor;the motor being of the type with a programmable electronic control of the speed and phase, the motor being provided with braking means, and wherein the rods and cranks are designed and arranged in such a way that, when the folders are in the closed position, the rods and the cranks are aligned with each other, this aligned position is taken as a zero reference point and;a sensor connected to a programmable processor to detect the zero reference point to control the operation of the motor, wherein in order to drive the folders through a complete cycle of closing and opening, the motor executes only one pulse to transfer the rods and cranks from one to the other of two limit positions, which limit positions are spaced apart from the zero reference point by an identical distance which can be varied according to the format of the products to be packaged.