Abstract: A zigzag folding apparatus for a form printing machine, having: a pair of rolls for outfeeding a paper strip being mounted to folding arms for folding the paper strip in a zigzag, one of the folding arms having a swing lever synchronized for swinging motion with the arm, a swing center of the lever coinciding coaxially with the point of contact between both the rolls, so that the rolls can perform an auxiliary folding operation to assist the folding operation of the folding arms under the condition in which the point of outfeeding the paper strip remains stationary; and a swing drive mechanism for activating the swing lever having main shafts on the drive side and out shafts for a swing section disposed in parallel relationship, the main shaft and the output shaft being connected one another by means of a shift transmitting mechanism in which a ratio of transmitting is chaged by operating a screw from the outside, so that the adjustment can be made according to a width of swing on the swing lever and the loca

Abstract: In a form printing machine having a printing section provided with a printing unit comprising a plate cylinder, a blanket cylinder and an impression cylinder, a change speed means for changing the rotation speed of the impression cylinder independently of the plate cylinder and the blanket cylinder is provided.

Abstract: A combustion device comprising a plurality of regenerative units formed by a plurality of separate radially extending compartments each containing a plurality of corrugated highly conductive metal plates compressed together with the corrugations in the adjacent plates intersecting each other at right angles so as to provide meandering passages for the gases between the adjacent corrugated plates; a rotary switching valve provided at one end of said regenerative means for controlling the flow of said waste gases flowing therethrough; a reaction zone provided at the other end of said regenerative means in which said waste gases are reacted; and a temperature-adjusting chamber located within said reaction zone and provided with an auxiliary combustion burner and an excess-heat disposal branch conduit.