Pump assembly

A pump assembly comprising:

• a cylinder having a top and a bottom that is open and a hollow portion formed therein, wherein the top of the cylinder has a first wing protruding in an outward direction from an outer peripheral surface thereof;
• a sealing part having at least a portion thereof inserted into the cylinder and at least partly sealing an upper portion of the cylinder, wherein a top of the sealing part has a second wing protruding in the outward direction from an outer peripheral surface thereof;
• a stem configured to move downward in reply to an external force to vary internal pressure of the cylinder;
• an elastic member disposed between the stem and the sealing part and configured to apply an elastic force to the stem from the sealing part;
• and
• a housing coupled to the cylinder and surrounding a top of the cylinder, wherein the housing is configured to detachably couple the pump assembly to a container, the housing comprising:
• at least one accommodation portion having a top and a bottom that is open and a hollow portion formed therein to accommodate at least portions of the stem and the elastic member therein, wherein the at least one accommodation portion includes a first accommodation portion and a second accommodation portion;
• a side peripheral wall disposed spaced apart from the at least one accommodation portion in the outward direction and having a coupling portion formed on an inner peripheral surface of the side peripheral wall, wherein the coupling portion is configured to detachably couple to the container;
• and
• a connection portion extending in the outward direction from an outer peripheral surface of the at least one accommodation portion to connect the side peripheral wall and the at least one accommodation portion,
• wherein the at least one accommodation portion is inserted into the sealing part by a given depth to couple the housing to the sealing part, and
• wherein when the housing is coupled to the container, the first wing and the second wing are pressurized downward by an inner surface of the housing and is configured to be fixed to a top of the container.