Patent ID: 6740020
Filing Date: 2004-05-25
Classification: B31B

Abstract:
An apparatus for successively making plastic bags, in which a panel material is fed longitudinally thereof and intermittently for a length, said panel material including a pair of panel portions superposed with each other to define aligned first and second side edges, said panel material further including a first side gusset portion disposed between and extending along said first side edges and a second side gusset portion disposed between and extending along said second side edges, one of said panel portions being cut as well as said first and second side gusset portions widthwise of said panel material so that an opening can be formed in said panel material whenever said panel material is fed intermittently, a bottom gusset material being then inserted between said pair of panel portions through said opening whenever said panel material is fed intermittently, said apparatus comprising:a trapezoidal plate including a short edge having opposite ends from which opposite oblique edges extend divergently, said trapezoidal plate comprising a double walled structure in which clearance means is formed between walls; drive means by which said trapezoidal plate is moved in a direction of height of trapezoid so that said short edge can be engaged with said bottom gusset material; and a pair of folding plates arranged to be engaged with said bottom gusset material and then inserted into said clearance means at positions corresponding to said oblique edges in accordance with the movement of said trapezoidal plate so that said bottom gusset material can be inserted into said clearance means by said folding plates to be folded into halves along said short edge and folded into said clearance means along said oblique edges, said bottom gusset material being then inserted between said pair of panel portions.