Patent ID: 8849157

Claim:
A cap for sealing a filling port formed in a developer container, the cap comprising: a base in the shape of a circular plate; a first cylindrical portion in the shape of a cylinder extending from a peripheral portion of the base in a first direction; a second cylindrical portion in the shape of a cylinder extending from the peripheral portion of the base in a second direction that is opposite to the first direction; a first projecting portion projecting radially outwardly from an outer circumferential surface of the first cylindrical portion with a predetermined projecting amount, the first projecting portion extending along a circumferential direction of the first cylindrical portion over an entire circumferential length of the first cylindrical portion; and a second projecting portion projecting radially outwardly from an outer circumferential surface of the second cylindrical portion with a projecting amount equal to the predetermined projecting amount of the first projecting portion, the second projecting portion extending along a circumferential direction of the second cylindrical portion over an entire circumferential length of the second cylindrical portion.