Developer supply container

1. A developer supply container detachably mountable to an image forming apparatus, said developer supply container comprising:

a discharge opening for permitting discharging of a developer;

a container body for accommodating the developer;

a snap hook member having an engaging projection for snap-hook engagement with an engageable member of the image forming apparatus;

a feeding portion for feeding the developer from said container toward said discharge opening by a rotating force received by said engaging projection from the engageable member;

wherein snap hook member has a bending modulus of 1400–20000 MPa.

2. A developer supply container according to claim 1 , wherein snap-hook member has a bending modulus of 2600–5590 MPa.

3. A developer supply container according to claim 1 or 2 , wherein said snap-hook member has a movable portion on which said engaging projection is provided, and wherein a ratio b/L of a width b of said engaging projection to a length L of the movable portion is 0.11–0.5.

4. A developer supply container according to claim 1 or 2 , wherein said snap-hook member has a movable portion on which said engaging projection is provided, and wherein a ratio t/L of a thickness t of said engaging projection to a length L of the movable portion is 0.05–0.15.

5. A developer supply container according to claim 1 or 2 , wherein said snap-hook member has a movable portion on which said engaging projection is provided, and wherein a ratio h/L of a height h of said engaging projection a length L of the movable portion is 0.04–0.25.

6. A developer supply container according to claim 1 or 2 , wherein said snap-hook member has a movable portion on which said engaging projection is provided, and wherein a ratio b/L of a width b of said engaging projection to a length L of the movable portion is 0.11–0.5, wherein a ratio t/L of a thickness t of said engaging projection to a length L of the movable portion is 0.05–0.15, and wherein a ratio h/L of a height h of said engaging projection a length L of the movable portion is 0.04–0.25.

7. A developer supply container according to claim 1 or 2 , wherein said snap-hook member has a force receiving portion for receiving a force in a direction of a rotational axis from said engageable member to open and close said discharge opening.

8. A developer supply container according to claim 7 , wherein said snap-hook member has a sealing portion for sealing said discharge opening, and the force received by said force receiving portion imparts a relative movement between said sealing portion and said container body.

9. A developer supply container according to claim 7 , wherein said force receiving portion is provided on said engaging projection.

10. A developer supply container according to claim 1 , wherein said snap-hook member has a releasing projection for receiving, from a hollow cylindrical member provided in the image forming apparatus, a force for displacement said engaging projection to release the snap-hook engagement with said engageable member.

11. A developer supply container according to claim 1 , wherein said snap-hook member has a transmitting portion for transmitting the rotating force to the container.

12. A developer supply container according to claim 11 , wherein said feeding portion has a plate-like member fixed on said container, and a projection provided inclined relative to the rotational axis on the plate-like member.

13. A developer supply container according to claim 11 , wherein said feeding portion has a projection provided and extended helically on an inner surface of said container body.