Cartridge piston
AssigneeFischbach KG Kunststoff-Technik
InventorAchim Helmenstein
Life of this patent
Estimating the term…
Abstract
A cartridge piston for pressing out a compound from a cartridge body is provided with a forwardly directed, elastic sealing lip which is arranged to bear against the cartridge wall. To allow for escape of air while the piston is being introduced, air passages are provided on the sealing lip. In a wall portion of the side wall, the piston has a non-circular shape so that, in certain regions, the abutment of the piston on the cartridge wall is less close than in other regions. In this manner, the outflow of air to the outside is facilitated. Further, the piston is arranged in its inserted state in a sealing abutment on the cartridge wall, thus precluding ingress of air into the cartridge.
Claims15
A cartridge piston comprising a tubular piston body with a longitudinal central axis, said piston body having a surrounding side wall and being closed at its front end by a piston end face, said side wall being provided with at least one flexible sealing lip, wherein said side wall further comprises a surrounding wall portion whose radiant as defined relative to the longitudinal central axis is provided with variations in a circumferential direction when in a relaxed state and not subject to external forces, wherein said cartridge piston is insertable into a cartridge and an unwound length of the outer contour of the surrounding wall portion is slightly oversized relative to an unwound length of an interior circle of the cartridge, whereby at the end of an applying process, a displacement of material will have led to an equalization along the circumference of the piston, whereby the piston will throughout its circumference be in biased abutment on a wall of the cartridge.
Dependencies are inferred from the claim text.