Combination new master supply and used master receiving assembly

Claim 1

A rotary offset printing machine comprising: a rotary master cylinder having means for releasably holding master plates mounted thereon, means for storing a stack of new master plates to be mounted on the master cylinder for printing therewith and a stack of used master plates removed from the master cylinder after printing therewith, and means for selectively and successively taking master plates from the stack of new master plates, moving said master plates toward the master cylinder and mounting said plates thereon, removing the mounted master plates from the master cylinder and moving the removed master plates toward and storing them with the stack of used master plates, wherein the machine includes a wall at a fixed position with respect to the master cylinder and includes means for removably securing the storing means to said wall, said storing means comprising: a new master plate tray for storing a stack of new master plates thereon, said new master plate tray having an opening facing said wall and forming a passageway for new master plates taken from the stack of new master plates by the means for mounting master plates on the master cylinder and moved toward the master cylinder thereby; a used master plate tray for storing a stack of used master plates, said used master plate tray having an opening facing the same wall of the machine as the tray for storing new master plates to form a passageway for master plates removed from the master cylinder and moved toward the stack of used master plates on the used master plate tray by the means for removing master plates from the master cylinder, said used master plate tray including a bottom and a sliding plate thereon provided with a stopper for limiting the distance between said wall of the machine and the end of the used master plate tray which is opposite therefrom and means for adjusting the distance of the stopper from said opening of the used master plate tray, said sliding plate being provided with a guide protuberance having a ridge whose height from the bottom of the used master plate tray increases in the direction toward said stopper; and means for fixedly securing together the new master plate tray and the used master plate tray to form a single integral unit, whereby new master plates enter the machine from the same side through which used master plates are ejected from the machine, thereby allowing an operator of the machine to observe the supply of both new and used master plates from the same side of the machine, and whereby the new and used master plate trays and the stacks of master plates thereon can be removed from the machine as a single integral unit and replaced on the machine as a single integral unit.