Apparatus for expressing a plastic mass from one or more cartridges

An apparatus for expressing a pasty mass from a cartridge, comprising:

• a housing having a longitudinally extending portion in which an elongated cartridge containing a pasty mass and having a movable bottom is received;
• a piston in said housing displaceable longitudinally in line with said cartridge and bearing against said bottom to drive said pasty mass out of said cartridge;
• and
• a drive including an electric motor in said housing operatively connected with said piston for displacing said piston from a starting position corresponding to a full cartridge to an end position corresponding to complete discharge of the pasty mass from said cartridge, said housing having a handle extending transversely of said longitudinally extending portion, and a cartridge holder on said portion receiving said cartridge and provided with an outlet nozzle for discharging said pasty mass, said apparatus including a second piston operatively connected to said drive, said outlet nozzle being provided with a mixer, and said cartridge holder being capable of receiving at least one cartridge having a pair of cylindrical chambers with respective movable bottoms, each chamber receiving a respective pasty mass and communicating with said mixer, said pistons respectively bearing against said respective movable bottoms, said drive including a speed-reducing transmission connected with said electric motor and a mechanism in said housing for displacing said pistons, said motor and said transmission being received in said handle and said transmission having an output shaft detachably connectable with a driven shaft of said mechanism, said mechanism including a pair of piston rods each connected to a respective one of said pistons, a yoke connecting said piston rods, a flexible tension member connected to said yoke and adapted to be wound on said driven shaft whereby winding of said tension member on said driven shaft displaces said yoke to displace said piston rods until said pistons reach said end position.