Container and pump assembly thereof

A pump assembly, which is suitable for being mounted on a container body and comprises a pressing rod, the pressing rod having a rod body, a connecting part bottom wall, a connecting part side wall and a piston part, a lower end of the rod body being connected to the connecting part bottom wall, and the connecting part side wall protruding upwardly from the connecting part bottom wall and being arranged at a periphery of the rod body, the pump assembly comprising:

• a main housing having a bottom housing, an inner cylinder housing and an outer cylinder housing, the inner cylinder housing and the outer cylinder housing both protruding upwardly from the bottom housing, the inner cylinder housing defining a cylindrical chamber, the outer cylinder housing being located at a periphery of the inner cylinder housing and defining an annular space with the inner cylinder housing, and the bottom housing being provided with a pumping port, in communication with the container body, in an intermediate part defined by the inner cylinder housing;
• and
• a built-in member having a top housing wall, an inner cylinder wall and an outer cylinder wall, the inner cylinder wall and the outer cylinder wall both protruding downwardly from the top housing wall, the inner cylinder wall defining a through hole for the rod body to pass through, and the outer cylinder wall being located at a periphery of the inner cylinder wall and defining an annular chamber with the inner cylinder wall;
• wherein the connecting part bottom wall is arranged in the cylindrical chamber, the connecting part side wall is in slidably sealing contact with an inner wall surface of the inner cylinder housing, and the piston part is arranged in the annular chamber and is in slidably sealing contact with each of an outer wall surface of the inner cylinder wall and an inner wall surface of the outer cylinder wall;
• and
• the built-in member is configured to be movable in the outer cylinder housing from a lower position in which the outer cylinder wall of the built-in member is at least partially located in the annular space to a higher position in which the built-in member is arranged to be locked by means of a locking structure.