This invention relates to a punch for punching markings into rolled material such as bars, ingots, billots or slabs, relative to which the rolled material is guided, including a toolholder movable by means of a controlled piston-cylinder arrangement, the punch types being settable automatically.
Such apparatus are known (see for instance U.S. Pat. No. 3,306,186). They are provided with a plurality of punch plates which are rotatably mounted on a common shaft guided in a toolholder. The toolholder is firmly arranged on a slide which is movable by means of a controlled reciprocating cylinder. In such apparatus all punch markings can be produced only simultaneously, i.e. in one operation, in the event the marking to be provided on the rolled material consists of a plurality of letters, figures or other symbols. This brings about the essential disadvantage that in the event of a non-planar end face or cutting surface of the rolled material or in the event of an inclined position of the rolled material in relationship to the punch plates uniform punch markings readily to be discriminated are not insured. An apparatus is already known wherein the slide carrying the toolholder with its slideway as well as the reciprocating cylinder associated with the slide are firmly arranged at the lower side of a support plate horizontally pivotable in counteraction to the lateral pressure of helical springs and wherein at the slideways at the end face two spaced, horizontally arranged rod-shaped feelers projecting beyond the end face of the slideways are positioned which upon engaging the rolled material set the punch plates via the support plate parallel to the surface of the rolled material to be provided with the marking. A proper punch marking is achieved with this apparatus only, however, in the event that the end face of the rolled material is substantially planar. When the end face is non-planar, the punch plates are only able to engage in varying depths in spite of a setting parallel to the end face of the rolled material. A further disadvantage inherent to the conventional apparatus is that the marking regarding the number of individual punch types is dependent on the number of punch plates with which the apparatus is equipped, i.e. for punching for instance a five-digit number five punch plates are required. Furthermore, in the prior art apparatus the spacing of the individual punch markings relative to one another is not variable.