Machine for perforating high density poly-ethylene film or the like film material

A machine for perforating high density polyethylene film material or the like, comprising a feed roller for supplying film material to be perforated from a roll thereof, cooperating male and female rollers between which film material from the feed roller passes for perforation, and a take up means for receiving the perforated film material, the male roller carrying for rotation therewith a plurality of circumferentially spaced blade members, means for mounting each blade for reciprocal motion relative to the surface of the male roller between a first position wherein the blade member projects from the surface of the male roller and a second position wherein the blade member is retracted into the male roller, means for biasing each blade member into one of its first and second positions, an independently operable actuating member linked respectively to each blade member for forcing the associated blade member into the other of its first and second positions in opposition to the biasing means, an indexing mechanism including a plurality of selectively located actuating means mounted for movement in coordination with the rotation of the male roller and arranged to cooperate with the actuating members of the blade members in such manner that upon rotation of the male roller the actuating means are brought successively into engagement with selected actuating members whereby the associated blade members are successively forced into their other positions, means for causing the actuating means to remain in engagement with the actuating members during a partial rotation of the male roller and for thereafter being successively disengaged from the actuating members to allow the biasing means to return the blade members to their one positions, the angular distance over which the actuating means remain in engagement with the selected actuating members being chosen such that, in the vicinity of the female roller, the blade members linked with the selected actuating members are in their projecting position for perforation of film material passing between the male and female rollers and the blade members linked to the non-selected actuating members are in their retracted position, recesses within the female roller which are entered by the selected blade members during perforation of the film, and means for adjusting the indexing means whereby the spacing and number of actuating means may be changed to vary the selection of blade members.