Patent ID: 9512603
Filing Date: 2016-12-06
CPC Classification: E03D,F16K

Claim Text:
1. A flushing mechanism, comprising: a housing having a housing wall and a housing bottom connected to the housing wall, the housing wall having a cylindrical inner surface that surrounds an axis, the cylindrical inner surface defining an inner cavity; an outfall provided on the housing bottom, surrounding the axis, and being connectable to a wash pipe; a guide rod disposed along the axis, and being axially restrained relative to the housing; a first piston that hermetically slips on the cylindrical inner surface and the guide rod at the same time along an axis direction, the first piston dividing the inner cavity into a lower cavity contacting with the housing bottom, and a relative upper cavity, a lower part of the first piston being provided with a ring protuberance; a first spring loading the first piston, and being installed in the upper cavity and surrounding the guide rod, the first spring applying an elastic force on the first piston from the housing and driving the first piston to move downward, thus reducing a volume of the lower cavity and expanding a volume of the upper cavity; a second piston that hermetically slips on the guide rod along the axis direction, and being located between the first piston and the housing bottom, the second piston having a seal assembly that includes a large seal ring surrounding an outboard of a bottom of the second piston, and a small seal ring located at a central part of the second piston; a second spring loading the second piston and surrounding the guide rod, the second spring applying an elastic force on the second piston from the housing and driving the second piston to move upward; and a control valve that comprises the seal assembly of the second piston and the ring protuberance of the first piston, the ring protuberance configured to pass through an annular opening in the bottom of the second piston to contact the large seal ring of the seal assembly of the second piston, whereby when the first piston slips downward, the ring protuberance causes a preloading, bending and deformation of the large seal ring of the seal assembly of the second piston, the large seal ring of the seal assembly of the second piston sealing over the small seal ring due to the preloading, bending and deformation, thus facilitating water in a ring exterior lower cavity to flow out of the outfall.