Patent ID: 8777826
Filing Date: 2014-07-15
Classification: B31B

Abstract:
1. An apparatus for successively making plastic bags each of which includes panel portions, side gusset portions and a bottom gusset portion, each of the side gusset portions having opposite end portions at one of which an auxiliary gusset portion is formed, the bottom gusset portion being combined with the auxiliary gusset portion, the plastic bag further including an opening formed between bottom protrusions protruding from the bottom gusset portions, the apparatus comprising: panel material feeding means by which upper and lower webs of panel material are opposed to and superposed on each other and fed longitudinally thereof and intermittently, each of the webs of panel material having first and second side edges, the panel portions being formed by the webs of panel material; side gusset material supply means by which a sheet of side gusset material is folded into halves, superposed into two layers and then supplied to and interposed between the webs of panel material to extend widthwise thereof whenever the webs of panel material are fed intermittently, the sheet of side gusset material having opposite end portions one of which is spaced from the first side edge of panel material, the side gusset portion and the auxiliary gusset portion being formed by the sheet of side gusset material; temporarily fixing means by which one of the webs of panel material is temporarily fixed to one of the layers of side gusset material, the other web of panel material being temporarily fixed to the other layer of side gusset material, at one of the end portions of side gusset material after the sheet of side gusset material is interposed; joint means by which the webs of panel material are joined to each other along a longitudinal joint line predetermined adjacent to the first side edge of panel material; and guide means by which each of the webs of panel material is guided to be deformed from the first side edge thereof after being temporarily fixed and joined and when being fed so that one of the webs of panel material can be folded along a longitudinal first folded line spaced from the longitudinal joint line to open the webs of panel material and form a surface on the webs of panel material, one of the layers of side gusset material being folded along the longitudinal first folded line to open the layers of side gusset material along with the auxiliary gusset portion and form a surface on the layers of auxiliary gusset portion, one of the webs of panel material being turned along a longitudinal turned line formed between the longitudinal joint line and the longitudinal first folded line to make a turned portion formed in one of the webs of panel material and superposed on the surface of the webs of panel material and the surface of the layers of auxiliary gusset portion, the other web of panel material being folded along a longitudinal second folded line spaced from the longitudinal joint line to make a folded portion formed in the other web of panel material and superposed on the surface of the webs of panel material and the surface of the layers of auxiliary gusset portion, the bottom gusset portion being formed by the turned portion and the folded portion, the opening being formed between the bottom protrusions which are formed between the first side edges of panel material and the longitudinal joint line.