A head depression type dispenser comprises a cylinder formed of an elastic material such as rubber. The cylinder is arranged between a head and a cap, and is constructed to operate as a piston for sucking and pressurizing liquid by axial deformation of the cylinder upon movement of the head. When the...http://www.google.com.au/patents/US4589573?utm_source=gb-gplus-sharePatent US4589573 - Head depression type dispenser
