Cap with valve

A cap with valve comprising:

• (a) a cap body installed at an opening portion a container and provided with a fluid flow path and an annular projection projecting inward at an inner circumference of said fluid flow path;
• (b) an annular valve body provided with an inner circumferential lip element projecting upward at inner circumferential edge and an outer circumferential lip element projecting downward at outer circumferential edge, said inner circumferential lip element being positioned at inside of the annular projection of the cap body and said outer circumferential lip element being capable of abutting on an upper surface of the annular projection of the cap body;
• (c) a first disk-shaped support plate arranged at upper side of said valve body and provided at a lower surface with a seal member of the inner circumferential lip element of the valve body and with a support member supporting the outer circumferential lip element of the valve body from upper side of the valve body and provided with a fluid flowing hole penetrating the upper and lower surfaces between the seal member and the support member;
• (d) a first spring means arranged within the fluid flow path of said cap body at upper side of said first support plate and biasing the first supprt plate downward;
• (e) a second annular support plate arranged at lower side of the valve body and at inside of the annular projection of the cap body and provided at an upper surface with a support member supporting the inner circumferential lip element of the valve body from lower side of the valve body, and at the center with a fluid flowing hole penetrating the upper and lower surface;
• and
• (f) a second spring means arranged within the fluid flow path of the cap body at lower side of said second support plate and biasing the second support plate upward.