Thermoregulator of a block cylinder used for an offset press

In an offset press in which the image of a block is at first transferred to a rubber blanket and further transferred to a printing paper so as to effect printing, an offset press comprising a liquid filled within the inside of a block cylinder on which said block is mounted, a first closed loop heat transfer system to circulate the liquid from said inside of said block cylinder to be cooled by cooling means externally thereof and effect desired heat transfer from said liquid during circulation thereof to provide major temperature control of the liquid, a second closed loop cooling tube mounted inside of said block cylinder providing temperature control of said liquid, a cooler for supplying a cooling medium to said cooling tube from the outside of said block cylinder and a controlling means for controlling cooling action of said cooler depending upon the temperature of the liquid within said block cylinder.