Dispensing cartridge with storage cylinder and feeding piston

A dispensing cartridge comprising:

• a storage cylinder for holding contents to be dispensed;
• a feeding piston slidably disposed within said cylinder, said feeding piston including an end, said end having a bottom surface facing the contents contained within said cylinder;
• and
• a plurality of radially extending venting grooves provided in said bottom surface, each of said venting grooves having opposed inner and outer ends, the inner ends communicating with a centrally disposed venting bore, the depth of said venting grooves continuously increasing from the outer ends toward said venting bore.

A dispensing cartridge comprising:

• a storage cylinder,
• a feeding piston including an end, said end having a bottom surface facing the cartridge contents, said bottom surface being provided with radially extending venting grooves, each having opposed inner and outer ends, the inner ends of each of the venting grooves communicating with a centrally disposed venting bore and the outer ends of each of the venting grooves communicating with a V-shaped circular groove;
• a sealing ring, inserted in a wall of said feeding piston, said sealing ring being inserted at a distance from the end of the feeding piston facing the cartridge contents;
• a sealing lip additionally provided on said end, the V-shaped groove formed between the lip and the piston wall, and
• an overflow chamber disposed annularly around said venting bore, said overflow chamber, as well as said venting bore, being sealed by closure means which further seals said venting bore from said overflow chamber.