Patent Publication Number: US-9902579-B2

Title: Feeding device with slide

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a feeding device, and more particularly, to a feeding device utilizing a slide to place sheets. 
     2. Description of the Prior Art 
     Digital processing machines, such as scanners, copy machines, and multifunction printers are often equipped with automatic document feeders (ADFs) for users to put a plurality of sheets at once instead of one by one manually. Please see  FIG. 9 .  FIG. 9  is a sectional diagram of a conventional feeding device in the prior. As shown in  FIG. 9 , a plurality of sheets S is put in a paper passage P. A feeding device senses the sheets S and drives a sheet-feeding roller A to rotate. The sheet-feeding roller A cooperates with a friction pad B to separate the plurality of sheets S and feed the plurality of sheets S one by one to the paper passage P at a downstream side of the sheet-feeding roller A. However, the sheets S may not be so rigid that the sheets S contact the sheet-feeding roller A first when being placed. A surface of the sheet-feeding roller A is made of rough material, so as to separate the sheets S easily. A friction force generated between the sheet-feeding roller A and the sheets S makes the sheets S bent easily when the sheets are placed and the feeding device is not activated. When the feeding device is activated and the sheet-feeding roller A begins rotating, the bent sheets S will be creased and damaged, which leads to a paper jam and a feeding failure, especially feeding the thin sheets S. 
       FIG. 10  is a sectional diagram of another conventional feeding device in the prior art. As shown in  FIG. 10 , a pickup roller C is added at an upstream side of the sheet-feeding roller A. The pickup roller C holds and conveys the plurality of sheets S to the sheet-feeding roller A and the friction pad B. The sheets S contact the pickup roller C when being placed. Similarly, the pickup roller C is made of material with a high friction coefficient, and such a situation of the bent sheets S also happens to the pickup roller C. Since a paper jam causes damage to sheets and inconvenience when people use digital processing machines, there is a need to develop an effective mechanism to solve the above-mentioned problems. 
     SUMMARY OF THE INVENTION 
     In order to solve the above-mentioned drawbacks, the present invention is to provide a feeding device utilizing a slide to place sheets for protecting sheets from damage and ensuring a smooth sheet-feeding process. 
     According to the claimed invention, a feeding device for a digital processing machine includes a paper passage, a sheet-feeding roller, a friction device, and a slide. The sheet-feeding roller is disposed on the paper passage. The friction device is disposed at a location opposite to the sheet-feeding roller. The sheet-feeding roller separates a sheet with the friction device. The slide is disposed by a left side and a right side of the sheet-feeding roller. The slide is lowered from a first position to a second position when the sheet-feeding roller rotates, such that the sheet contacts the sheet-feeding roller. 
     According to the claimed invention, the slide is disposed at an axle of the sheet-feeding roller. 
     According to the claimed invention, the slide is higher than the sheet-feeding roller when the slide is at the first position, and the slide is lower than the sheet-feeding roller when the slide is at the second position. 
     According to the claimed invention, the feeding device further includes a one-way bearing sheathed on an axle of the sheet-feeding roller. The one-way bearing lowers the slide from the first position to the second position when the sheet-feeding roller rotates. 
     According to the claimed invention, a feeding device for a digital processing machine includes a paper passage, a pickup roller, a sheet-feeding roller, a friction device, and a slide. The pickup roller is disposed on the paper passage for picking up a sheet. The sheet-feeding roller is disposed on the paper passage and at a downstream side of the pickup roller. The friction device disposed at a location opposite to the sheet-feeding roller. The slide is disposed by a left side and a right side of the pickup roller. The slide is lowered from a first position to a second position when the pickup roller rotates, such that the sheet contacts the pickup roller. 
     According to the claimed invention, the slide is disposed at an axle of the pickup roller. 
     According to the claimed invention, the slide is higher than the pickup roller when the slide is at the first position, and the slide is lower than the pickup roller when the slide is at the second position. 
     According to the claimed invention, the feeding device further includes a one-way bearing sheathed on an axle of the pickup roller. The one-way bearing lowers the slide from the first position to the second position when the pickup roller rotates. 
     According to the claimed invention, the feeding device further includes a belt encircling an axle of the pickup and an axle of the sheet-feeding roller. The belt drives the sheet to pass through the paper passage. 
     According to the claimed invention, the feeding device further includes an additional pickup roller and an additional sheet-feeding roller. The pickup roller and the additional pickup roller are coaxially disposed with each other, and the sheet-feeding roller and the additional sheet-feeding roller are coaxially disposed with each other. 
     In summary, the present invention provides the feeding device with the slide capable of switching between the first position and the second position with different heights. The sheet contacts the slide with a lower friction coefficient first at the first position and then contacts the pickup roller or the sheet-feeding roller with a higher friction coefficient at the second position, such that the sheet can be kept flat without being bent during a sheet-feeding process, so as to ensure a smooth feeding process and protect the sheet from damage. 
     These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic diagram of a feeding device according to a first embodiment of the present invention. 
         FIG. 2  is a diagram of the feeding device with a slide in a first position according to the first embodiment of the present invention. 
         FIG. 3  is a diagram of the feeding device with the slide in a second position according to the first embodiment of the present invention. 
         FIG. 4  is a schematic diagram of the feeding device according to a second embodiment of the present invention. 
         FIG. 5  is a diagram of the feeding device with the slide in a first position according to the second embodiment of the present invention. 
         FIG. 6  is a diagram of the feeding device with the slide in a second position according to the second embodiment of the present invention. 
         FIG. 7  is a schematic diagram of the feeding device according to a third embodiment of the present invention. 
         FIG. 8  is a diagram of the slide and a one-way bearing according to the third embodiment of the present invention. 
         FIG. 9  is a diagram of a conventional feeding device in the prior art. 
         FIG. 10  is a diagram of another conventional feeding device in the prior art. 
     
    
    
     DETAILED DESCRIPTION 
     Please refer to  FIG. 1  to  FIG. 3 .  FIG. 1  is a schematic diagram of a feeding device  100  according to a first embodiment of the present invention.  FIG. 2  is a diagram of the feeding device  100  shown in  FIG. 1  with a slide  40  in a first position according to the first embodiment of the present invention.  FIG. 3  is a diagram of the feeding device  100  shown in  FIG. 1  with the slide  40  in a second position according to the first embodiment of the present invention. The feeding device  100  adapted for a digital processing machine (not shown in figures) includes a paper passage P, a sheet-feeding roller  20 , a friction device  30 , and the slide  40 . The sheet-feeding roller  20  is disposed on the paper passage P. The slide  40  is disposed by a left side and a right side of the sheet-feeding roller  20  and at an axle  22  of the sheet-feeding roller  20 . The feeding device  100  further includes a power source  60  connected to the sheet-feeding roller  20  for driving the sheet-feeding roller  20  to rotate and to move a sheet S to a downstream side of the paper passage P. The feeding device  100  further includes a one-way bearing  42  sheathed on the axle  22  of the sheet-feeding roller  20 . The one-way bearing  42  lowers the slide  40  from a first position to a second position when the sheet-feeding roller  20  rotates. 
     As shown in  FIG. 2 , the friction device  30  is disposed at a location opposite to the sheet-feeding roller  20 . When the sheet S is placed, the sheet S contacts the slide  40  located at a higher location in the first position, instead of contacting the sheet-feeding roller  20  located at a lower location. The slide  40  can be a rib structure, and a contacting area between the slide  40  and the sheet S is small. The slide  40  can be made of material with a low friction coefficient, such that the sheet S is not bent by a friction force but placed flat. 
     As shown in  FIG. 1  and  FIG. 3 , the power source  60  drives the sheet-feeding roller  20  to rotate in a counterclockwise direction when the feeding device  100  is activated. The one-way bearing  42  (shown in  FIG. 1 ) lowers the slide  40  from the first position to the second position. Since the slide  40  for supporting the sheet S is lowered to the second position below the sheet-feeding roller  20 , the sheet S drops and contacts the sheet-feeding roller  20  smoothly. Meantime, the sheet-feeding roller  20  rotates and cooperates with the friction device  30  to separate the plurality of sheets S one by one and to convey the sheet S to the downstream side of the paper passage P. The friction device  30  can include a friction wheel or a friction pad. In this embodiment, the friction device  30  is a friction pad but it is not limited to this embodiment. By lowering the slide  40 , the sheet S can contact the sheet-feeding roller  20  flat instead of being bent. 
     Please refer to  FIG. 4  to  FIG. 6 .  FIG. 4  is a schematic diagram of the feeding device  100  according to a second embodiment of the present invention.  FIG. 5  is a diagram of the feeding device  100  shown in  FIG. 4  with the slide  40  in a first position according to the second embodiment of the present invention.  FIG. 6  is a diagram of the feeding device  100  shown in  FIG. 1  with the slide  40  in a second position according to the second embodiment of the present invention. The feeding device  100  includes the paper passage P, a pickup roller  10 , the sheet-feeding roller  20 , the friction device (shown in  FIG. 5  and  FIG. 6 ), and the slide  40 . The pickup roller  10  is disposed on the paper passage P for picking up the sheet S. The sheet-feeding roller  20  is disposed on the paper passage P and located at a downstream side of the pickup roller  10 . Different from the first embodiment, the feeding device  100  of the second embodiment further includes the pickup roller  10 , and the slide  40  is disposed by a left side and a right side of the pickup roller  10 . In this embodiment, the sheet S contacts the pickup roller  10  first. The pickup roller  10  can hold the plurality of sheets S and convey the sheets S to the sheet-feeding roller  20  and the friction device  30  for separating the sheet S. Therefore, by arrangement of the slide  40  disposed by the left side and the right side of the pickup roller  10 , the sheet S is not bent when contacting the pickup roller  10 . Furthermore, the feeding device  100  further includes a belt  50  encircling an axle  12  of the pickup  12  and the axle  22  of the sheet-feeding roller  20 . The belt  50  is driven by the power source  60  for helping to convey the sheet S to pass through the paper passage P. 
     As shown in  FIG. 5 , the friction device  30  is disposed at a location opposite to the sheet-feeding roller  20 . The slide  40  is disposed at the axle  12  of the pickup roller  10 . When the sheet S is placed, the sheet S contacts the slide  40  located at a higher location in the first position, instead of contacting the pickup roller located at a lower location. A contacting area between the slide  40  and the sheet S is small because the slide is a rib structure. The slide  40  can be made of material with a low friction coefficient, such that the sheet S is not bent by a friction force but placed flat. 
     As shown in  FIG. 4  and  FIG. 6 , the power source  60  drives the pickup roller  10  to rotate in a counterclockwise direction when the feeding device  100  is activated. The one-way bearing  42  (shown in  FIG. 4 ) disposed at the axle  12  of the pickup roller  10  lowers the slide  40  from the first position to the second position. Since the slide  40  for supporting the sheet S is lowered to the second position below the pickup roller  10 , the sheet S drops and contacts the pickup roller  10 . The pickup roller  10  rotates to drive the sheet S to pass through the paper passage P and to convey the sheet S to a downstream side of the sheet-feeding roller  20 . Then, the sheet-feeding roller  20  cooperates with the friction device  30  to separate the plurality of sheets S. By lowering the slide  40 , the sheet S can contact the pickup roller  10  smoothly instead of being bent. 
     Please refer to  FIG. 7 .  FIG. 7  is a schematic diagram of the feeding device  100  according to a third embodiment of the present invention. Different from the second embodiment, the feeding device  100  further includes an additional pickup roller  10 ′ and an additional sheet-feeding roller  20 ″. The additional pickup roller  10 ′ is coaxially disposed with the pickup roller  10 . The additional sheet-feeding roller  20 ′ is coaxially disposed with the sheet-feeding roller  20 . The pickup roller  10  and the additional pickup roller  10 ′ can be the same components. The sheet-feeding roller  20  and the additional sheet-feeding roller  20 ′ can be the same components. In such a way, the forces received by the sheet S are balanced and equalized when the sheet are picked up or separated, such that the sheet S is not deflected by ununiformed forces during a sheet-feeding process. 
     Please refer to  FIG. 8 .  FIG. 8  is a diagram of the slide  40  and the one-way bearing  42  according to the third embodiment of the present invention. The operational principle of the third embodiment also can be implemented in the first embodiment and in the second embodiment. The slide  40  is disposed at the axle  12  of the pickup roller  10 . The one-way bearing  42  is sheathed on the axle  12  of the pickup roller  10  and includes a protrusion  421 . The slide  40  includes a sliding slot  422 . The protrusion  421  is engaged with the sliding slot  422 , as illustrated in the bold arrow shown in  FIG. 8  when being assembled. When the axle  12  of the pickup roller  10  is driven to rotate by the power source  60 , the one-way bearing  42  rotates and drives the protrusion  421  to slide down in the sliding slot  422 , as illustrated in the narrow arrow shown in  FIG. 8 . Therefore, the slide  40  is pushed down by the protrusion  421  and moved from the higher first position to the lower second position, such that the sheet S contacts the pickup roller  10  flat. However, the operational mechanism of the present invention is not limited to this embodiment, and the slide  40  can be lowered by other mechanisms or devices, such as using a solenoid valve. 
     In contrast to the prior, the present invention provides the feeding device with the slide capable of switching between the first position and the second position with different heights. The sheet contacts the slide with a lower friction coefficient first at the first position and then contacts the pickup roller or the sheet-feeding roller with a higher friction coefficient at the second position, such that the sheet can be kept flat without being bent during a sheet-feeding process, so as to ensure a smooth feeding process and protect the sheet from damage. 
     Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.