US 5,114,394 AGranted

Punching attachment for bag making machine

OwnerDale R. Madseninventor

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Abstract

A single, fluid pressure-operated cylinder, which has a conventional slitter blade and punch releasably secured to the lower end of its piston rod, is secured to a plastic bag making machine so that the operating ends of the blade and punch project toward a stationary, horizontal support surface across which overlapping plastic webs pass during bag manufacturing. The webs are secured against movement during a slitting and punching operation by a pressure plate, which is also mounted on the piston rod for movement thereby into engagement with the plastic webs to clamp them against the stationary support surface during the initial advance of the rod. As the rod continues to advance it moves the blade and punch through the now-clamped plastic webs, after which the piston rod is retracted and the parts return to their inoperative positions.

Claims12

Dependent claims

A web clamping, slitting and punching device for plastic bag making machines of the type having a stationary web supporting surface across which each of two overlapping webs of plastic, bag-making film travel during the manufacture of bags on said machine, comprising

a first bracket disposed to be removably fixed to said machine adjacent one side thereof,
a second bracket removably mounted for vertical adjustment on said first bracket and having thereon a lateral projection disposed to overlie said stationary web supporting surface,
a fluid pressure-operated cylinder having a reciprocable piston rod projecting from one end thereof, and disposed to be connected to a supply of fluid under pressure operative intermittently to reciprocate said rod between retracted and advanced positions, respectively,
means releasably mounting said cylinder on said lateral projection on said second bracket with one end of said piston rod extending downwardly beneath said lateral projection,
means removably mounting a slitting blade and a hole punch on said one end of said rod for reciprocation by said rod between retracted positions in which the operating ends of said blade and punch are disposed in spaced, confronting relation to said stationary web supporting surface and the webs passing thereover, and advanced positions in which said operating ends of said blade and punch engage and pass through said webs and into registering opening in said stationary web supporting surface, and
web clamping means resiliently supported on said one end of said rod adjacent said blade and punch and having thereon a clamping surface overlying said web supporting surface normally to be spaced therefrom when said rod is in its retracted position,
said web clamping means being operative upon the initial movement of said rod from its retracted to its advanced position to urge said clamping surface toward said stationary web supporting surface to engage and operatively clamp said plastic webs against movement on said stationary surface before said operating ends of said blade and punch engage said webs, and
said blade and punch mounting means being operative to urge said operating ends of said blade and punch through said webs during the remaining movement of said rod to its advanced position.

5 more elements

In a plastic bag making machine of the type having a stationary web supporting surface across which each of two overlapping webs of plastic, bag making film travel and a fluid pressure-operated web punching and slitting device, said surface having therein a pair of adjacent apertures beneath said device for accommodating the operating ends of, respectively, a web slitting blade and a web hole punch which form part of said device, the improvement wherein said device comprises

a bracket having thereon a lateral projection,
means releasably securing said bracket on said machine for vertical adjustment relative to said web supporting surface, and to support said lateral projection in spaced, confronting relation to said web supporting surface,
means releasably securing a fluid pressure-operated cylinder over an opening in said lateral projection, said cylinder having a reciprocable piston rod which extends at one end thereof through said opening and toward said web supporting surface,
means resiliently mounting a pressure plate on said one end of said piston rod for reciprocation thereby into and out of clamping engagement with the webs supported on said support surface, said pressure plate having therethrough a pair of adjacent apertures registering with and similar in configuration to said pair of apertures in said web supporting surface, and
means releasably securing said web slitting blade and said web hole punch on said piston rod with the operating ends thereof registering with the respective apertures in said web supporting surface and said pressure plate, and operative upon each reciprocation of said piston rod to force the operating ends of said blade and punch through the overlapping webs on said web supporting surface after the webs have been clamped against said surface by said pressure plate.

2 more elements

Dependencies are inferred from the claim text.