US Patent 9687866 Liquid soap dispenser

A liquid soap dispenser includes a cap adapted to be mounted onto a container. A cylinder longitudinally and rotatably extends through the cap. A tube is longitudinally connected to a lower end of the cylinder. A discharge tube is partially longitudinally received in the cylinder. The discharge tube has a lower end received in the cylinder and abutting against an inner periphery of the cylinder and is reciprocally moved relative to the cylinder. A push-button is mounted onto a top of the discharge tube. A negative pressure relative to the space in the container is intermittently formed in the cylinder such that the liquid soap in the container will sequentially pass through the tube, the discharge tube and the push-button when the push-button is reciprocally pressed and the piston of the discharge tube is reciprocally moved relative to the cylinder.