Master switch to actuate dampener in automatic duplicator

Claim 1

In a lithographic offset printing machine for use with a plurality of discrete master sheets each having marking indicia thereon indicating the number of prints to be made from each of the discrete master sheets, the combination comprising: a main cylinder for carrying said each of the discrete master sheets; a transfer cylinder disposed in contiguous relation with said main cylinder for receiving an offset image from said each of the discrete master sheets; a pressure cylinder disposed on contiguous relation with said transfer cylinder for pressing copy sheets against said transfer cylinder; a master sheet feeding device to feed said each of the discrete master sheets to said main cylinder; a clamp mounted on said main cylinder for retaining said each of the discrete master sheets thereon; a switch on said main cylinder positioned to be engaged by a leading edge of each said master sheet fed to said main cylinder to thereby actuate said switch; drive means on said main cylinder coupled to said clamp and responsive to actuation of said switch by said masteR sheet to close said clamp to thereby retain said master sheet on said main cylinder; a moistening device for moistening said each of the discrete master sheets; control means responsive to said actuation of said switch by said master sheet for producing a control signal when said master sheet is retained by said clamp; means responsive to said control signal for operating said moistening device for moistening said master sheet retained in said main cylinder; reading means disposed between said master sheet feeding device and said main cylinder to scan the marking indicia on said each of the discrete master sheets and generating a first electrical pulse signal representing the number of prints to be made therefrom; a memory device electrically connected to said reading means to store said first electrical pulse signal indicative of the number of prints to be made from said each of the discrete master sheets; means for actuating an ink supply device to cause the application of ink and water to said each of the discrete master sheets after moistening; copy sheet feeding means to feed the copy sheets to said pressure cylinder and including means for generating a second electrical pulse signal indicative of the number of copy sheets being fed to said pressure cylinder; comparing means electrically connected to said memory device and said means for generating said second electrical pulse signal, said comparing means comparing said first and second electrical pulse signals and generating a completion signal when the value of said first electrical pulse signal equals that of said second electrical pulse signal; means for actuating an image erasing device to remove the image from said transfer cylinder in response to the stopping of said copy sheet feeding means; means for removing said each of the discrete master sheets from said main cylinder upon completion of printing; and control means operable by said completion signal to terminate operation of said copy sheet feeding means and to operate said removal means to remove said each of the discrete master sheets from said main cylinder, said control means being further operable to actuate said master sheet feeding means to feed a following individual master sheet to said main cylinder.