Dosing devices for viscous materials particularly highly viscous materials

Claim 1

A dosing device for dosing viscous materials, particularly highly viscous materials, including a dosing cylinder for a main material and at least one dosing cylinder for an additive to be dosed in an in each case fixed but variable volume ratio with respect to the main material, with a pressure feeding of the main material and additive into the dosing cylinders, each dosing cylinder containing a drivable dosing piston, a common drive and said dosing pistons being arranged on a common frame, a respective supply connection issuing into each dosing cylinder and a respective outlet connection issuing therefrom, each of said connections being openable or closable by means of a respective two-way valve, said dosing cylinders being arranged substantially parallel to one another, the dosing pistons of said dosing cylinders being drivable with an identical stroke and the dosing piston of the at least one additive dosing cylinder being contructed as a plunger with a smaller cross-section than the cross-section of the dosing cylinder for said main material and the plunger being sealingly guided in an interchangeable guide bush of said additive dosing cylinder, said at least one additive dosing cylinder being connected as a sub-assembly in an interchangeable manner by means of a rapidly connectable and releasable coupling to said frame, the dosing piston of the cylinder for said main material and the plunger of said at least one additive dosing cylinder engaging with a cross-beam which is displaceable by said drive parallel to itself along the axes of said dosing piston and plunger, the plunger of said at least one additive dosing cylinder not being connected to said cross-beam, the two-way valve being a cone-plug forming one unit with said additive dosing cylinder, said cone-plug of the at least one additive dosing cylinder being connected by means of a detachable coupling to a rotary drive.