Dosing device in a tube filling machine

Abstract

The invention relates to a dosing device in a tube filling machine, comprising a dosing chamber in a housing, said chamber having an inlet and an outlet for the medium which is to be dosed. At least one adjustable dosing piston whose volume in the dosing chamber is adjustable is provided in addition to a control bushing which is rotationably mounted in the housing, having at least one connecting channel which joins the inlet or the outlet to the dosing chamber when the control bushing is in a predetermined rotated position. The control bushing has a conical section which is sealingly arranged on a complementary conical section of the dosing chamber and which can be raised therefrom, in addition to an axial through hole in which the at least one dosing piston is displaceably guided. At least one section of the dosing chamber is disposed on the side next to the wider end of the conical section of the control bushing, so that the conical sections are pushed against each other when the pressure in the dosing chamber is increased as a result of movement of the dosing piston.

1  through  9  cancelled.  
     
     
         10 . A dosing device for a dosing medium in a tube filling machine, the device comprising: 
 a housing defining a dosing chamber, said housing having an inlet opening and an outlet opening for receiving and discharging the dosing medium;    a control sleeve rotably disposed in said housing, said control sleeve having at least one connecting channel to connect said inlet opening or said outlet opening to said dosing chamber at respective predetermined rotated positions of said control sleeve, said control sleeve having a conical section which can be sealingly disposed on a complementary conical section of said housing and which can be lifted therefrom, wherein at least one portion of said dosing chamber is defined by a wide end of said conical section, said control sleeve also having an axial bore;    a first dosing piston, said first dosing piston formed as an annular piston guided within said axial bore of said control sleeve, said annular piston having an axial bore; and    a second dosing piston displaceably guided within said annular piston axial bore, said second dosing piston disposed coaxially with respect to said first dosing piston, wherein said first dosing piston and said second dosing piston are displaceable to change a volume of said dosing chamber, wherein said control sleeve conical section is pressed against said housing conical section when a pressure in said dosing chamber is increased in response to motion of at least one of said first dosing piston and said second dosing piston.    
     
     
         11 . The dosing device of  claim 10 , wherein said first and said second dosing piston can be adjusted as a unit.  
     
     
         12 . The dosing device of  claim 10 , wherein said first and said second dosing piston can be adjusted independently of each other.  
     
     
         13 . The dosing device of  claim 10 , wherein each of said first and said second dosing pistons has its own servomotor drive.  
     
     
         14 . The dosing device of  claim 10 , wherein said axial bore of said control sleeve defines a rinsing chamber with enlarged diameter in which a piston section of the said first dosing piston can be received with play, wherein said rinsing chamber can be supplied with rinsing liquid through at least one first supply opening.  
     
     
         15 . The dosing device of  claim 10 , wherein rinsing liquid can be introduced through at least one second supply opening of said housing into a space formed between said housing and said control sleeve when said control sleeve conical section is lifted.  
     
     
         16 . The dosing device of  claim 10 , wherein at least one of said housing, said control sleeve, said first dosing piston, and said second dosing piston are made from ceramic material.  
     
     
         17 . The dosing device of  claim 10 , wherein said at least one connecting channel is formed by an axial groove.  
     
     
         18 . The dosing device of  claim 17 , wherein at least two axial grooves are provided in said control sleeve through which said inlet opening or said outlet opening can be connected to said dosing chamber.  
     
     
         19 . The dosing device of  claim 18 , wherein said two axial grooves are formed in said conical section of said control sleeve.