| 摘要 |
A device for dispensing a viscous product comprises a cylindrical barrel having a piston sealingly slidable therewithin under the action of a reciprocating rack actuated by a manually-operable push-button. The piston includes a sealing skirt which is separate from the catch-engagement lips which allow unidirectional entrainment of the piston by the reciprocating rack, and it serves to seal the piston to the rack to prevent wastage of product. |
