Automatic document feeder having mechanism for releasing paper jam
The present invention relates to an automatic document feeder having a mechanism for releasing paper jam by disconnecting the transmission device. The automatic document feeder includes a driving motor, a transmission device, a plurality of paper transfer rollers, a swing arm and a releasing arm. The driving motor is used for providing driving power. The transmission device and is coupled to the driving motor for transmitting the driving power. The swing arm is coupled to some of the transmission elements and operated in either a connection state or a disconnection state. The releasing arm is selectively contacted with the swing arm to have the swing arm enter the disconnection state or separated from the swing arm to have the swing arm enter the connection state. The paper jam is released when the swing arm is operated in the disconnection state.
1. An automatic document feeder having a mechanism for releasing a paper jam, said automatic document feeder comprising:
a main body;
an upper cover pivotally connected to the main body and comprising a protrusion structure;
a transfer roller assembly for transmitting paper;
an inner roller assembly including a first paper transfer roller, a second paper transfer roller and a third paper transfer roller for receiving the paper transmitted from the transfer roller assembly and the first paper transfer roller is engaged with the second paper transfer roller and the third paper transfer roller;
a driving motor for providing driving power;
a transmission device coupled to said driving motor for transmitting said driving power to the roller assemblies including a sixth gear engaged with the driving motor, a fifth gear being coaxial with the first paper transfer roller, a seventh gear and an eighth gear;
a swing arm connected to the sixth gear, the seventh gear and the eighth gear; and
a releasing arm rotatably coupled to the main body;
whereby when the upper cover is closed the releasing arm is depressed by the protrusion structure of the upper cover and the releasing arm is separated from the swing arm, and the fifth gear is engaged with the seventh gear or the eighth gear according to the rotational direction of the motor and,
when the upper cover is opened, the releasing arm is rotated to engage the swing arm and the fifth gear is separated from the seventh gear and the eighth gear.
2. The automatic document feeder according to claim 1 wherein the transmission device includes a first gear and when the driving motor is rotated in an anti-clockwise direction, the first gear is rotated in a clockwise direction whereby the eighth gear is engaged with the fifth gear and the fifth gear is rotated in a clockwise direction, and when the driving motor is rotated in said clockwise direction, the first gear is rotated in said anti-clockwise direction whereby the seventh gear is engaged with the fifth gear and the fifth gear is rotated in said clockwise direction.
3. The automatic document feeder according to claim 2 wherein the main body includes a protruding shaft and a first protruding button.
4. The automatic document feeder according to claim 3 wherein the releasing arm includes a pivotal hole such that the releasing arm is rotated with the protruding shaft of the main body.
5. The automatic document feeder according to claim 4 wherein the swing arm includes a second protruding button whereby when the upper cover is opened, the concave portion of the releasing arm engages with the second protruding button of the swing arm, so that both of the seventh gear and the eighth gear fail to contact with the fifth gear.
6. The automatic document feeder according to claim 5 further including a resilient element for connecting the releasing arm and the first protruding button of the main body.