초록 ▼

Apparatus wherein sheet material is longitudinally step-advanced by alternately being gripped and released in a guide path by a reciprocative gripper, and alternately released and gripped in a gripping station, the sheet material being restrained against buckling from the guide path by guide means a

Apparatus wherein sheet material is longitudinally step-advanced by alternately being gripped and released in a guide path by a reciprocative gripper, and alternately released and gripped in a gripping station, the sheet material being restrained against buckling from the guide path by guide means adjacent to both of opposite faces of the sheet material, and the guide means enabling the reciprocative gripper gripping the sheet material in the guide path to be operated for effecting a forward feeding stroke having the sheet material released in the gripping station, and subsequently a backward stroke, throughout which latter stroke the reciprocative gripper is in a released condition with reference to the sheet material and the latter is gripped in the gripping station.

대표청구항 ▼

Apparatus for step-feeding sheet material, said apparatus including: guideway and first anvil means comprising a pair of opposed guide plate means for constraining sheet material against buckling of the latter when sheet material is disposed in a guide path between said pair of opposed guide plate m

Apparatus for step-feeding sheet material, said apparatus including: guideway and first anvil means comprising a pair of opposed guide plate means for constraining sheet material against buckling of the latter when sheet material is disposed in a guide path between said pair of opposed guide plate means and is fed Along said guide path, said pair of guide plate means each having a set of slots therein and said slots in said sets longitudinally leading along said guide in and being spaced apart from one another in said set laterally of said guide path, and first anvil means disposed along said guide path forwardly of said sets of slots and accessibly opposite apertured structure of one of said pair of opposed guide wall means; power-operated first clamp means comprising driven first presser means projecting through said apertured structure of said one of said pair of opposed guide plate means for clamping sheet material in said guide path against said first anvil means and for releasing sheet material from said presser anvil means; guide means; guide follower, second anvil and power-operated second clamp means comprising, second anvil means, power-operated second clamp means, and follower means on said guide means for carrying said second anvil means and said power-operated second clamp means forwardly toward said first anvil means and said first presser means, and rearwardly, said second anvil means having a set of projections extending through said set of slots in a first of said pair of opposed plate means slightly into said guide path, and said power-operated second clamp means including driven second presser means, said second presser means having a set of projections aligned with said set of slots in the other of said pair of opposed guide plate means for clamping sheet material in said guide path against said set of projections of said second anvil means and for releasing sheet material from said second anvil means, and said follower means carrying said second anvil means and said power-operated second clamp means for sheet material clamped against said second anvil means by said second presser means to be forwardly fed having said set of projections of said second anvil means and said set of projections of said second presser means follow said sets of slots in said pair of opposed guide plate means; power-operated drive means connected with said guide follower, second anvil and power-operated second clamp means for moving said follower means to and from forward and rearward positions along said guide means and to carry said second anvil means and said power-operated second clamp means; and means for controlling said power-operated drive means and said power-operated first and second clamp means to step-feed sheet material forwardly along said guide path.