The present invention relates to a machine for perforating, in the transverse direction, paper webs, such as toilet paper and household paper, and webs of similar material. The main object of the invention is to provide a machine which is simple and safe in its construction and which operates at a very high accuracy and further ensures a perforation without causing any noticeable wearing of the parts of the machine involved in the perforation. The object aimed at has been achieved by shaping the abutment means of a longitudinal border reaching into the movement path of the knifes and outside the periphery of the roller, and an elongated pad extending parallel to the roller axis, said pad at the side turned towards the roller provided with abutment and sliding surfaces, for the knife which are extending in the transverse direction of the pad, said surface arranged with some distance from each other and adapted to rebound when being hit by the knife.
A perforating apparatus is disclosed for rewinding machines and the like which includes a rotating roller (5), on which cutting blades (31) are disposed. A shaft (3) carries a perforating counter-blade (33) provided with indentations. An oscillating drive (57, 59, 61, 63, 65) is combined with the shaft (3) which causes the counter-blade 33 to move with reciprocating translation motion in a direction parallel to the axis of the rotating roller (5), so as to avoid a concentration of wear in the cutting blades (31).
A rotary punch for the production of pre-shaped outer and inner cuts on mng webs or individual blanks of paper or the like, and more particularly, for the preparation of envelopes, flat bags or the like, includes rotating cutting tools whose cutting edges describe an envelope cylinder and at the instant of cutting impinge on a stationary abutment aligned at a slight inclination to the axis of rotation of the tools and so clamped that the operative edge of the abutment is everywhere at the same radial distance from the axis of rotation. The punch has a holder for the abutment, which holder has a bed molded from a curable liquid, and a cutting ledge of circular cross-section which is secured in the bed.
A wood incisor for perforating the surface of lumber. The incisor includes a roll having a plurality of spaced sockets in its circumferential surface. Incisor teeth are received in the sockets and are clamped in the sockets by means of camming elements.
