Abstract: A stopper for an opening of a container such as a thermos. The stopper includes a pushbutton, a fluid flow channel extending between an inlet and an outlet, and a movable plug portion positioned adjacent the inlet. A biasing member biases the plug portion into sealing engagement with the inlet thereby preventing the contents of the container from flowing into the channel. A cam follower is disposed upon a cam surface opposing the biasing member. The cam follower is rotatable by the pushbutton relative to the cam surface from a closed position to an open position and when so rotated, exerts a biasing force on the cam surface sufficient to overcome the biasing force exerted by the biasing member on the plug portion and space the plug portion from the inlet allowing the contents of the container to flow into the channel and out the outlet.

Abstract: A stopper for an opening of a container such as a thermos. The stopper includes a pushbutton, a fluid flow channel extending between an inlet and an outlet, and a movable plug portion positioned adjacent the inlet. A biasing member biases the plug portion into sealing engagement with the inlet thereby preventing the contents of the container from flowing into the channel. A cam follower is disposed upon a cam surface opposing the biasing member. The cam follower is rotatable by the pushbutton relative to the cam surface from a closed position to an open position and when so rotated, exerts a biasing force on the cam surface sufficient to overcome the biasing force exerted by the biasing member on the plug portion and space the plug portion from the inlet allowing the contents of the container to flow into the channel and out the outlet.