Abstract: Each section of a buckle sheet feed folding machine is driven by a silicon controlled rectifier (SCR) controlled DC motor. The speed of the first section is infinitely variable by means of a rheostat in the SCR control. A signal related to the speed of the first section is applied to all subsequent SCR controls such that the speed of all fold sections will follow changes made to the speed of the first section. Each section also includes a rheostat to vary the relative speed between that section and the first. A switch is provided at each subsequent section in order to disconnect the first section speed signal and apply an independent control signal.

Abstract: A folding machine includes movable or adjustable rollers, or rolls, each of which forms nips with two fixed rollers. The movable rollers have freedom of movement substantially circumferentially about the two fixed rollers substantially on projected radii of the two fixed rollers, to set the spacings between the fixed and the movable rollers.The mechanism for supporting and adjusting the movable rollers includes levers pivoted at the axes of the fixed rollers having contoured mounting surfaces. The contoured mounting surfaces are rounded substantially on projected radii of the surfaces of the respective fixed rollers. The shafts of the movable rollers ride on the contoured surfaces.Automatic adjustment of the spacing between the movable rolls and the fixed rolls is provided by cams which operate on the levers to hold them in specific "spacing" relationships once paper stock has been run between the movable to fixed rolls to move the movable rollers a desired distance from the fixed rollers.