Patent Publication Number: US-4579328-A

Title: Copy paper feeding device for electrophotographic copying machine

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to an electrophotographic copying machine and, more particularly, to a copy paper feeding device. 
     An electrophotographic copying machine produces an electrostatic latent image corresponding to a pattern image on a document such as a manuscript or book to be copied. Toner particles are electrically adhered to the latent image, so that the latent image becomes visible to form a toner image. The toner image is transferred onto a copy paper via a transference charger. 
     Normally, the copy paper is automatically fed by an automatic paper feeder which stores a great number of copy papers. It may be preferable to copy onto a paper different from the papers stored in the automatic paper feeder which will then be used to receive the toner image thereon. For this purpose, any desired paper is inserted manually while operating a manual paper feeding device. 
     Conventionally, the manual paper feeding device is such that a particular opening through which different paper is to be inserted separately provided from the automatic paper feeder having a paper cassette or tray. Thus, a special opening is needed to operate the manual paper feeding system, which prevents the copying machine from being compact and simple. Therefore, it is desired to provide an improved paper feeding device. 
     SUMMARY OF THE INVENTION 
     Accordingly, it is an object of the present invention to provide an improved paper feeding device for feeding papers, automatically and manually. 
     It is another object of the present invention to provide an improved automatic paper feeding device for serving as part of a manual paper feeding device. 
     It is a further object of the present invention to provide an improved automatic paper feeding device for preventing a manual paper feeding mode from being carried out while the automatic paper feeding mode is carried out. 
     Briefly described, in accordance with the present invention, an electrophotographic copying machine comprises a paper feeding device serving as an automatic paper feeder and a manual paper feeder. The paper feeding device includes a cover positioned at its upper portion. To enable an automatic paper feeding mode, the paper feeding device functions to feed a great number of papers as stored therein by pulling out the cover from the copying machine. To enable a manual paper feeding mode, the cover of the paper feeding device is able to transport a manually inserted paper by pushing in the cover back into the copying machine. In synchronization with the pushing-in and the pulling-out of the cover, if the automatic paper feeding mode is selected, a stopper engages with the cover so that the manually inserted paper is interrupted. Responsive to slidably positioning the cover, the stopper is pivotally rotated for opening and closing an opening through which the manually inserted paper is to be inserted. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention and wherein: 
     FIG. 1 is a cross-sectional view of a paper feeding device according to the present invention, showing an automatic paper feeding mode; 
     FIG. 2 is a perspective view of the paper feeding device of FIG. 1; and 
     FIG. 3 is a cross-sectional view of the paper feeding device, showing a manual paper feeding mode. 
    
    
     DESCRIPTION OF THE INVENTION 
     FIG. 1 shows a cross-sectional view of a paper feeding device of the present invention in an automatic paper feeding mode. FIG. 2 shows a perspective view of this paper feeding device. 
     Referring now to FIGS. 1 and 2, the paper feeding device 1 comprises a paper cassette 1 for storing a great number of copy papers 2, a cover 3, some paper pick-up rollers 4, a bottom plate 5, a spring 6, a paper downing claw 7, a paper guide 8, a stopper 10, a stopper support member 11, a stopper release lever 12, and a lever support member 13. 
     The cassette 1 is detachably attached to a paper insertion opening of an electrophotographic copying machine. The plurality of paper pick-up rollers 4 are positioned to confront the paper stack in the cassette 1 when the cassette 1 is fully inserted into the machine. The plurality of pick-up rollers 4 are rotated according to paper feeding signals from a control circuit of the copying machine to pick up single copy paper. The cover 3 is disposed at an upper position of the cassette 1 for carrying the stopper 10, the stopper support member 11, the lever 12, and the lever support member 13. The cover 3 covers the papers 2 within the cassette 1. The cover 3 is slidable and carries the stopper 10, the stopper support member 11, the lever 12, and the lever support member 13. The base plate 5 supports the papers 2 while the base plate 5 is biased by the spring 6 to lift the papers up to a paper pick-up level. The claw 7 is provided for preventing the top paper from floating upward and assuring that the papers are positioned at an appropriate level. 
     According to the present invention, on the cover 3, means is provided for allowing a manually inserted paper 2&#39; to be transported and for preventing the manually inserted paper 2&#39; from being inserted. The means includes the stopper 10 having a bent edge for interrupting the manually inserted paper 2&#39; when the edge of the stopper 10 is engaged with the edge of the cover 3. The other side of the stopper 10 is pivotally supported by the stopper support member 11 fixed on the cover 3, so that the stopper 3 can be rotated. 
     The paper guide 8 is disposed on the bottom surface and front end of the cover 3. The guide 8 is made of a thin stainless plate to somewhat cover the papers 2. When the paper pick-up rollers 4 are rotated, the rollers 4 come in contact with the manually inserted paper 2&#39; but are prevented from being in contact with the papers 2 in the cassette 1 due to the paper guide 8. The reason why the guide 8 is made of stainless steel so that the rollers 4 will contact with the manually inserted paper 2&#39; with an appropriate pressure with the help of deflection by the guide 8. 
     The stopper release lever 12 is supported by the lever support member 13, so that the shaft of the lever 12 can be rotated. The end of the lever 12 rests on the cover 3. When the cover 3 is inserted into the copying machine with the stopper release lever 12, an arm 14 of the lever 12 collides with a front edge of the paper opening in the copying machine. The bent edge of the stopper 10 engages with the front edge of the cover 3, as stated above. 
     There is a clearance between the stopper 10 and the cover 3 where they are joined by the stopper support member 11 for inserting the paper 2&#39; as well as a manual paper insertion opening 15. 
     FIG. 3 shows a manual paper feeding mode in the paper feeding device of FIGS. 1 and 2. 
     To enable the automatic paper feeding mode, as FIG. 1 shows, the cover 3 is pulled out from the paper insertion opening by sliding it away from the paper pick-up rollers 4, so that the guide 8 is positioned well away from the rollers 4. Therefore, the paper pick-up rollers 4 confront the papers 2 stored within the cassette 1 to pick up the papers 2 in the automatic paper feeding mode. Even if the paper 2&#39; is manually inserted into the clearance at the inside of the stopper support member 11 between the stopper 10 and the cover 3, the paper 2&#39; is interrupted by the front edge of the stopper 10 engaged with the front edge of the cover 3 as shown in FIG. 1. 
     On the contrary, to enable the manual paper feeding mode, as FIG. 3 shows, the cover 3 pushed into the paper insertion opening of the copying machine by sliding it forward toward the paper pick-up rollers 4. Since the cover 3 carries the stopper 10, the stopper support member 11, and the lever support member 13, they are also pushed into the copying machine. With this insertion, the arm 14 of the stopper release lever 12 collides with the front edge of the paper insertion opening of the copying machine, so that the stopper 10 is pivoted counterclockwise in FIG. 3, because the arm 12 is lifted around the fulcrum which is the contact point between the arm 12 and the cover 3. An opening 15 for the manual paper feeding mode opens at the inside of the stopper 10 because the engagement between the stopper 10 and the cover 3 is released. Simultaneously, the guide 8 fully covers the papers 2 within the cassette 1, so that the guide 8 confronts the paper pick-up rollers 4 to shade the papers 2. Under the circumstances, the paper 2&#39; is manually inserted to confront the paper pick-up rollers 4 through the opening 15, so that the paper 2&#39; can be inserted into the copying machine by the rollers 4. 
     To enable the automatic paper feeding mode again, the cover 3 is pulled out from the copy paper insertion opening, so that the guide 8 is far away from the paper pick-up rollers 4. Here, because the cover 3 carries the lever 12 with the arm 14, the collision between the arm 14 of the lever 12 and the front edge of the paper insertion opening of the copying machine is released, so that the stopper 10 is rotated clockwise to close the manual paper insertion opening 15. Even if the paper 2&#39; is manually inserted, it is stopped by the stopper 10 from engaging with the front edge of the cover 3, so that the paper 2&#39; cannot confront the paper pick-up rollers 4. Instead, the papers 2 within the cassette 1 are inserted into the copying machine according to paper feeding signals supplied from a control circuit of the copying machine. 
     While only certain embodiments of the present invention have been described, it will be apparent to those skilled in the art that various changes and modifications may be made therein without departing from the spirit and scope of the present invention as claimed.