Clutch, drive transmission device and image forming apparatus

A clutch comprising:

• an inputting member rotatable by input of an input torque;
• a rotatable outputting member to which the input torque is transmitted from said inputting member;
• a stationary member including a cylindrical inner wall surface surrounding said inputting member and said outputting member and configured to be mounted on a mounting portion in a rotation prevented state;
• and
• a contact member contactable to said inputting member, said outputting member and said stationary member,
• wherein said outputting member includes an output contact portion contactable to an input engaging portion of said inputting member,
• wherein said contact member is positioned between said outputting member and said stationary member and includes an arcuate first contact surface configured to contact the cylindrical inner wall surface of said stationary member and a second contact surface contactable to said output contact portion,
• wherein when the input torque for rotating said inputting member in one rotational direction is inputted, said outputting member and said contact member rotate in the one rotational direction in contact with said inputting member,
• wherein when a reverse input torque for rotating said outputting member in the one rotational direction is inputted, the input engaging portion of said inputting member and the output contact portion of said outputting member are spaced from each other, and said output contact portion of said outputting member urges the first contact surface against said stationary member by urging the second contact surface of said contact member thereby to prevent rotation of said outputting member in the one rotational direction,
• wherein when the input torque for rotating said inputting member in the other rotational direction opposite to the one rotational direction is inputted, said outputting member and said contact member rotate in the other rotational direction in contact with said inputting member, and
• wherein when a reverse input torque for rotating said outputting member in the other rotational direction is inputted, the input engaging portion of said inputting member and the output contact portion of said outputting member are spaced from each other, and said output contact portion of said outputting member urges the first contact surface against the cylindrical inner wall surface of said stationary member by urging the second contact surface of said contact member thereby to prevent rotation of said outputting member in the other rotational direction.

A clutch comprising:

• an inputting member rotatable by input of an input torque;
• a rotatable outputting member to which the input torque is transmitted from said inputting member;
• a stationary member including a cylindrical inner wall surface surrounding said inputting member and said outputting member and configured to be mounted on a mounting portion in a rotation prevented state;
• and
• a contact member contactable to said inputting member, said outputting member and said stationary member,
• wherein said outputting member includes an output contact portion contactable to an input engaging portion of said inputting member,
• wherein said contact member is positioned between said outputting member and said stationary member and includes an arcuate first contact surface configured to contact the cylindrical inner wall surface of said stationary member and a second contact surface contactable said output contact portion,
• wherein when a rotational force with respect to one rotational direction is inputted to said inputting member, said outputting member and said contact member rotate in the one rotational direction in contact with said inputting member,
• wherein when a rotational force for rotating said outputting member in the one rotational direction at a rotational speed faster than a rotational speed of said inputting member generates in said outputting member, the input engaging portion of said inputting member and the output contact portion of said outputting member are spaced from each other, and said output contact portion of said outputting member urges the first contact surface against said stationary member by urging the second contact surface of said contact member thereby to prevent rotation of said outputting member in the one rotational direction,
• wherein when a rotational force with respect to the other rotational direction opposite to the one rotational direction is inputted to said inputting member, said outputting member and said contact member rotate in the other rotational direction in contact with said inputting member, and
• wherein when a rotational force for rotating said outputting member in the other rotational direction at a rotational speed faster than a rotational speed of said inputting member generates in said outputting member, the input engaging portion of said inputting member and the output contact portion of said outputting member are spaced from each other, and said output contact portion of said outputting member urges the first contact surface against the cylindrical inner wall surface of said stationary member by urging the second contact surface of said contact member thereby to prevent rotation of said outputting member in the other rotational direction.