Driving roller assembly for paper feeding apparatus

Abstract

A driving roller assembly for a paper feeding apparatus is provided for driving a driving roller to move a piece of paper. The assembly includes a transmitting sleeve, a one-way coupling sleeve, and a driven block. The transmitting sleeve is provided for moving the one-way coupling sleeve to be engaged with the driven block, and driving the one-way coupling sleeve to rotate. The one-way coupling sleeve is coupled to the driven block for rotating the driven block in one rotational direction only, and thereby driving the driving roller to rotate. When the rotational speed of the driving roller is higher than that of the transmitting sleeve, or the transmitting sleeve stops rotating, the driving roller is rotated by other external force without interfering with the transmitting sleeve.

1 . A driving roller assembly for a paper feeding apparatus, for driving a driving roller conveying a piece of paper, wherein a shaft is disposed at a rotational axis of the driving roller, the driving roller assembly comprising:
 a transmitting sleeve, slid over the shaft, and having a canted edge formed at one end thereof, wherein the canted edge has an inclined angle with respect to the rotational axis of the driving roller, and one end of the canted edge extending towards outside of the transmitting sleeve along the rotational axis is formed into a first stopper;   a one-way coupling sleeve, slid over the shaft, and having a first one-way coupling end and an actuating end, wherein the actuating end is slidably contacted with the canted edge to move the one-way coupling sleeve along the rotational axis, and the actuating end is provided for being engaged with the first stopper, such that the transmitting sleeve drives the one-way coupling sleeve to rotate; and   a driven block, fixed to the shaft, and having a second one-way coupling end corresponding to the first one-way coupling end of the one-way coupling sleeve, wherein the first one-way coupling end is coupled to the second one-way coupling end in one rotational direction only, and the shaft is driven to rotate by coupling the one-way coupling sleeve to the driven block.   
     
     
         2 . The driving roller assembly for a paper feeding apparatus as claimed in  claim 1 , wherein the first one-way coupling end one-way coupling sleeve is coupled to the second one-way coupling end of the driven block in a first rotational direction, and it is separated from the second one-way coupling end in a second rotational direction opposite to the first rotational direction. 
     
     
         3 . The driving roller assembly for a paper feeding apparatus as claimed in  claim 2 , wherein when the transmitting sleeve rotates in the first rotational direction, the transmitting sleeve presses against the canted edge of the actuating end to move one-way coupling sleeve towards the driven block, and thereby the first one-way coupling end is coupled to the second one-way coupling end. 
     
     
         4 . The driving roller assembly for a paper feeding apparatus as claimed in  claim 1 , wherein an end of the canted edge towards inside of the transmitting sleeve along the rotational axis is formed into a second stopper. 
     
     
         5 . The driving roller assembly for a paper feeding apparatus as claimed in  claim 4 , wherein a notch is formed between the first stopper and the second stopper, and the canted edge is located within the notch. 
     
     
         6 . The driving roller assembly for a paper feeding apparatus as claimed in  claim 1 , wherein a slide block is protruded from the actuating end, and the slide block is slidably contacted with the canted edge, to presses against the first stopper. 
     
     
         7 . The driving roller assembly for a paper feeding apparatus as claimed in  claim 1 , wherein the other end, away from the canted edge, of the transmitting sleeve is connected to a driving device, and driven by the driving device. 
     
     
         8 . A paper feeding apparatus, comprising:
 a first driving roller, for conveying a piece of paper, wherein a shaft is disposed at a rotational axis of the first driving roller;   a transmitting sleeve, slid over the shaft, and having a canted edge formed at one end thereof, wherein the canted edge has an inclined angle with respect to the rotational axis of the driving roller, and one end of the canted edge extending towards outside of the transmitting sleeve along the rotational axis is formed into a first stopper;   a one-way coupling sleeve, slid over the shaft, and having a first one-way coupling end and an actuating end, wherein the actuating end is slidably contacted with the canted edge and drives the one-way coupling sleeve to move along the rotational axis, and the actuating end is provided for being engaged with the first stopper, such that the transmitting sleeve drives the one-way coupling sleeve to rotate;   a driven block, fixed to the shaft, and having a second one-way coupling end corresponding to the first one-way coupling end of the one-way coupling sleeve, wherein the first one-way coupling end is coupled to the second one-way coupling end in one rotational direction only, and the shaft is driven to rotate by coupling the one-way coupling sleeve to the driven block; and   a second driving roller, disposed with a rotational axis parallel to that of the first driving roller, for receiving the piece of paper conveyed by the first driving roller and then conveying the piece of paper, such that the piece of paper is continuously conveyed.   
     
     
         9 . The paper feeding apparatus as claimed in  claim 8 , further comprising a trigger element for detecting the arrival of a front edge of the piece of paper to be received by the second driving roller. 
     
     
         10 . The paper feeding apparatus as claimed in  claim 8 , further comprising a first driving element and a second driving element, wherein the first driving element is provided for driving the transmitting sleeve to rotate, and the second driving element is provided for driving the second driving roller to rotate.