In the past, the applicant has proposed an opening and closing valve that can be attached to a discharge port of a liquid container. As described in Japanese Utility Model Application Publication No. H05-083560, the opening and closing valve thereof is provided with a base end part having an inflow port for a liquid in a container, an operation lever for opening and closing the valve, a valve body which is opened and closed by rotating the operation lever, and a discharge port which communicates to the inflow port when the valve is opened. Furthermore, a male screw which helically engages with a female screw formed at the discharge port of the container is formed at the base end part where the inflow port is formed at the base end.
USPTO Backgrounds
USPTO Backgrounds