Patent Publication Number: US-2007104528-A1

Title: Paper feeding device

Description:
BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present invention relates to a paper feeding device, and in particular relates to a paper feeding device in a copy machine or a printer etc.  
      2. Description of the Related Art  
       FIG. 1  shows that a conventional paper feeding device  10  comprises a paper container  11  and a paper-transmitting mechanism  12 . The paper-transmitting mechanism  12  comprises an axle  121  and a roller  122 . The paper-transmitting mechanism  12  pivots on the axle  121 . The roller  122  rotates to transmit paper  20 . Moreover, a line L between the axle  121  and the roller  122  and paper  20  form an included angle θ. Compare  FIG. 1  with  FIG. 2 , the amount of paper  20  gradually decreases, thus, the paper-transmitting mechanism  12  pivots on the axle  121  and the included angle θ increases gradually, causing the position of the paper-transmitting mechanism  12  relative to the paper to change. Because the direction of a force exerted to each piece of paper by the paper-transmitting mechanism changes due to the variation in the position of the roller, the magnitude of the force changes too, paper jams and multi-feeding may occur in the paper feeding device  10  when a printer or a copy machine works.  
     BRIEF SUMMARY OF INVENTION  
      A detailed description is given in the following embodiments with reference to the accompanying drawings. The invention provides a paper feeding device. The paper feeding device comprises a paper container and a paper-transmitting mechanism. The paper container comprises a first connecting portion. The paper-transmitting mechanism comprises a second connecting portion. The first connecting portion and the second connecting portion can connected to keep the paper transmitting mechanism moving along a direction, whether increasing or decreasing the mount of paper in the paper container, a fixed angle between the paper-transmitting mechanism and paper in the paper container always exists and the force exerted to each piece of the papers in the paper container is constant. 
    
    
     BRIEF DESCRIPTION OF DRAWINGS  
      The present invention can be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings, wherein:  
       FIG. 1  is a schematic view of a conventional paper feeding device at full capacity;  
       FIG. 2  is a schematic view of a conventional paper feeding device having less paper than  FIG. 1 ;  
       FIG. 3  is a schematic view of a paper feeding device of one embodiment of the invention;  
       FIG. 4A  is a sectional cross view along  4 - 4  of  FIG. 3 ;  
       FIG. 4B  is a schematic view of a paper feeding device having less paper than  FIG. 4A ;  
       FIG. 5  is another embodiment of the invention; and  
       FIG. 6  is another embodiment of the invention. 
    
    
     DETAILED DESCRIPTION OF INVENTION  
      The following description is of the best-contemplated mode of carrying out the invention. This description is made for the purpose of illustrating the general principles of the invention and should not be taken in a limiting sense. The scope of the invention is best determined by reference to the appended claims..  
      Referring to  FIG. 3 , the paper feeding device  30  comprises a paper container  31  and a paper-transmitting mechanism  32 . The paper container  31  comprises two sides  311  and  312  and a carrying surface  313 . The paper-transmitting mechanism  32  is installed on the side  312  to transmit paper  40  out of the paper container  31  along an arrow A.  
      Referring to  FIGS. 3 and 4 A,  FIG. 4A  is a sectional cross section along  4 - 4  of  FIG. 3 . The paper container  31  comprises a first connecting portion  314  disposed on the side  312 . In this embodiment, the first connecting portion  314  is a groove. The paper-transmitting mechanism  32  comprises a second connecting portion  321  movably connected to the first connecting portion  314 . In this embodiment, the second connecting portion  321  is a protrusion, such as a T type protrusion. Moreover, the paper-transmitting mechanism  32  further comprises two rollers  322  and  323  and a driving device  324 . In this embodiment, the driving device  324  is a motor for driving the rollers  322  and  323  to transmit paper  40 . The paper-transmitting mechanism  32  and the carrying surface  313  form a fixed angle. In this embodiment, the fixed angle is 0 degree or 180 degree. Because paper  40  is placed flat on the carrying surface  313 , the carrying surface  313  is parallel to the paper. The paper-transmitting mechanism  32  is parallel to the carrying surface  313  and paper  40  thereon. The amount of paper  40  on the carrying surface  313  decreases because paper  40  is transmitted out of the paper container  31 , thereby, the paper-transmitting mechanism  32  descends along an arrow C.  
       FIG. 4B  shows the paper-transmitting mechanism  32  gradually descending. As amount of decreases paper, the paper-transmitting mechanism  32  stays parallel to the paper  40  on the carrying surface  313 . The paper-transmitting mechanism  32  and the paper  40  on the carrying surface  313  form a fixed angle, thus, the amount of force exerted on each piece of paper  40  by the paper-transmitting mechanism  32  is the same, thus, paper jams and muilt-feeding is prevented.  
       FIG. 5  shows another embodiment of a paper feeding device comprising the paper-transmitting mechanism  32   a  on the side  312   a  of the paper container  31 . The paper container  31  comprises two first connecting portions  314   a  and  314   a ′. The paper-transmitting mechanism  32   a  comprises a roller  322  and two second connecting portions  321   a  and  321   a ′. The second connecting portions  321   a  and  321   a ′ are respectively and movably connected to the first connecting portions  314   a  and  314   a ′. This embodiment is approximately similar to the embodiment of  FIG. 3 , thus, description of identical elements is omitted.  
       FIG. 6  shows another embodiment of a paper feeding device, wherein the paper-transmitting mechanism  32   b  comprises two rollers  322  and  323 , a transmitting mechanism  325 , an axle and a driving device (not shown). The driving device drives the axle  326 , and drives the transmitting mechanism  325 , and then drives the rollers  322  and  323 . The transmitting mechanism  325  may be a pulley or a gear drive. This embodiment is approximately similar to the embodiment of  FIG. 3 , thus, description of identical elements is omitted.  
      While the invention has been described by way of example and in terms of the preferred embodiments, it is to be understood that the invention is not limited to the disclosed embodiments. To the contrary, it is intended to cover various modifications and similar arrangements (as would be apparent to those skilled in the art). Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements.