Paper conveying apparatus

Abstract: A paper conveying apparatus is described having follower rollers (9) arranged opposite to and in contact with rotationally driven conveying rollers (8) and a second guide plate (5) arranged to form a predetermined space between the second guide plate (5) and a stationary first guide plate (3). The follower rollers (9) and the second guide plate (5) are supported on an openable/closable support plate (7) independently of each other. The follower rollers (9) are urged toward the conveying rollers (8) and the second guide plate (5) is urged toward the first guide plate (3) independently of each other. In the above arrangement, the openable/closable support plate (7) can be locked and unlocked easily to facilitate closing and opening.

Description: The present invention relates to a paper conveying apparatus of the type that can be used in copying machines, printers, paper sorters, and the like. A conventional paper conveying apparatus according to the preamble of claim 1 and which can be used in an image forming apparatus or the like is described with reference to Fig. 5. In the conventional paper conveying apparatus, a first guide plate 3 is mounted on a paper feeding deck body 25 so as to extend along the paper conveying direction. A second guide plate 5, which forms a paper conveying path 4 having a predetermined space t between the second guide plate 5 and the first guide plate 3, is elastically supported on an openable/closable support plate 7 and is urged toward the first guide plate 3. The openable/closable support plate 7 has one end pivotally connected to the body 25 by a hinge 6 and the other end can be locked to the body 25 by lock mechanisms 14. Rotationally driven conveying rollers 8 and follower rollers 9 are arranged opposite to and in contact with each other. Paper sandwiched between conveying rollers 8 and follower rollers 9 is carried in the paper conveying path 4. Generally, the support plate 7 is integrated with an openable/closable door 45 provided on the side portion of the body 25 as shown in Fig. 3. In the apparatus described above, in order for the paper to come in tight contact with the rotationally driven conveying rollers 8, the follower rollers 9 are urged towards the conveying rollers 8. To accomplish this, bearings 11 for supporting a support shaft 10 of the follower rollers 9 are elastically-supported on the second guide plate 5 by springs 12 so as to be urged toward the conveying rollers 8. Also, the second guide plate 5 is elastically supported at opposite ends by springs 13 on the support plate 7 so as to be urged toward the first guide plate 3. Accordingly, the springs 12 for urging the follower rollers 9 and the springs 13 for urging the second guide plate 5 impose opposing urging forces on the second guide plate 5. That is, when the urging force of the springs 12 urges the follower rollers 9 against the conveying rollers 8, the second guide plate 5 is pushed against the urging force of the springs 13 and is moved to a position indicated by the dotted chain line. Thus, the predetermined space t can not be maintained between the first guide plate 3 and the second guide plate 5. Accordingly, the paper can not be carried suitably. If the spring force of the springs 13 is increased to sufficiently maintain the space between both guide plates 3 and 5 at the predetermined value t , it is necessary to increase the hooking force of the lock mechanisms 14 provided on one end of the support plate 7. However, if the hooking force of the lock mechanisms 14 is too large, it becomes much more difficult to open and close the support plate 7. An object of the present invention is to provide a paper conveying apparatus having an openable/closable support plate that can be easily opened and closed. This object is solved according to the present invention by an apparatus including the features of claim 1. The present invention provides a paper conveying apparatus having a first guide plate secured in the paper conveying direction and a second guide plate proximate thereto. A paper conveying path is formed as a predetermined space between the second guide plate and the first guide plate. The second guide plate is elastically supported on an openable/closable support plate and is urged toward the first guide plate to sandwich paper between rotationally driven conveying rollers and follower rollers. The follower rollers and conveying rollers are arranged opposite to and in contact with each other. The follower rollers are elastically supported on the openable/closable support plate and are urged toward the conveying rollers in the paper conveying path to enable the rollers to forward the paper within the paper conveying path. The spring force for urging the follower rollers against the conveying rollers and the spring force for urging the second guide plate operate independently of each other. Therefore, the spring force being exerted on the second guide plate can be independently selected without considering the spring force on the conveying rollers. Accordingly, it is possible that the spring force being exerted on the second guide plate is relatively weaker than in the conventional apparatus thus allowing the hooking force for locking the support plate to be less than in the conventional apparatus. Hence, the support plate can be opened and closed easily. Additional objects and advantages of the invention will be set forth in the description which follows, and in part will from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized by means of the instrumentalities and combinations particularly pointed out in the appended claims. FIG. 1 is a plan view showing a main portion of an embodiment of the paper conveying apparatus according to the present invention. FIG. 2 is a side view taken along the direction of arrows II-II in FIG. 1. FIG. 3 is a perspective view showing a support plate of the paper conveying apparatus cooperating with an electrostatic photography copying machine. FIG. 4 is a cut away side view showing the configuration of the entire electrostatic photography copying machine. FIG. 5 is a plan view showing a main portion of a conventional paper conveying apparatus. Fig. 4 shows the configuration view of an electrostatic photography copying machine provided with the paper conveying apparatus 1 according to the present invention. In a deck body 25 of the paper feeding deck 21, a plurality of front loading type paper feeding cassettes 28 are horizontally mounted in stages. Paper feeding rollers 23 are provided above the front portions of the paper feeding cassettes 28, respectively. The paper conveying apparatus 1 further has a vertical paper conveying path 4 formed between opposing guide plates 3 and 5. A paper discharge outlet 29 is provided at the top end of the paper conveying path 4 and communicates with a curved conveying path 30 in the copying machine body 2. The curved conveying path 30 further communicates with a conveying path 31 which conveys paper to the center portion of the copying machine body 2. An image forming portion 32 for forming an image is provided at the center portion of the copying machine body 2 and an optical scanning system 33 is provided at the top portion of the copying machine body 2. A platen 34 covered with an openable/closable cover 35 is provided over the optical scanning system 33 at the upper surface of the copying machine body 2. The image forming portion 32 comprises a photosensitive drum 36, main charger 37, a developing device 38, a transferring charger 39, a separating charger 40, and a cleaning device 41, etc., which are disposed about the circumference of the photosensitive drum 36. A conveying belt 42 is provided to convey paper from the photosensitive drum 36 to a fixing device 43. Paper discharge rollers 44 are provided proximate to the fixing device 43 to discharge paper from the fixing device 43 to a paper discharge tray 46 attached to the exterior of the copying machine body 2. During operation of the electrostatic photography copying machine described above, an operator places an item to be copied (e.g. document) on the platen 34. The operator enters the number of copies to be made through an operation panel (e.g. ten-key panel, not shown) provided on the outside of the copying machine and activates copying start button (not shown). Then, the optical scanning system 33 detects the size of the item and the paper feeding rollers 23 feed the paper from the appropriate paper feeding cassette 28 into the paper conveying path 4. Paper fed from any of the paper feeding cassettes 28 by its corresponding paper feeding roller 23 passes a corresponding one of the smaller-diameter rollers 15, which contacts its corresponding one of the conveying rollers 8, and enters the paper conveying path 4. The paper entering the paper conveying path 4 abuts against the second guide plate 5, bends upward and is conveyed through the paper conveying path 4 by the conveying rollers 8 and the follower rollers 9 toward the paper discharge outlet 29. The paper passes through the paper discharge outlet 29 and enters the curved conveying path 30 in the copying machine body 2. In the copying machine body 2, the paper is fed from the curved conveying path 30, which communicates with the paper discharge outlet 29, to the conveying path 31. The paper is then conveyed through the conveying path 31 to the image forming portion 32 at the center portion of the copying machine body 2. The optical scanning system 33 exposes the item on the platen 34 to form an image on the photo-sensitive drum 36 and the image is transferred on the paper. Then, the paper is separated from the drum and conveyed by the conveying belt 42 to the fixing device 43. The fixing device 43 grabs the paper and the paper discharge rollers 44 discharge the paper onto the paper discharge tray 46. As shown in Fig. 3, first guide plates 3 are fixedly supported in the deck body 25 and are mounted in the vertical direction corresponding to the conveying direction of the paper. A second guide plate 5 is elastically supported on a support plate 7 which can be connected to the inner surface of a door 45 or integral with the door 45. The door 45 is openably/closably supported by the deck body 25 by hinges 6 and is locked in a closed position by lock mechanisms 14. As shown in Fig. 1, in the closed position of the door 45, the paper conveying path 4 having a predetermined space t is formed between each of the first guide plates 3 and the second guide plate 5 which is elastically supported on the support plate 7. One end of the support plate 7 is pivotally coupled to the side plate 27 of the deck body 25 by hinges 6, while the other end of the support plate 7 is lock-hooked by the lock mechanisms 14 to the side plate 26 of the deck body 25. Reception portions 14a of the lock mechanisms 14 are attached to the side plate 26, and insertion portions 14b extending from the support plate 7 insert into the reception portions 14a to lock the support plate 7 and the door 45 (see Fig. 3) in the closed position. When a handle (not shown) of the door 45 is pulled, the support plate 7 can be opened together with the door 45 as shown by a dotted chain line. The first guide plate 3 is secured at its opposite ends to side plates 26 and 27 of the deck body 25. In the position corresponding to each of the paper feeding cassettes 28, a pair of openings 3a are formed in the corresponding first guide plate 3, and the corresponding conveying rollers 8 are secured to driving shaft 17 so that the conveying rollers 8 partially project outwardly from the openings 3a into the paper conveying path 4. The driving shaft 17 is supported by a pair of bearings 16 secured to the side plates 26 and 27, respectively, and is rotated by a driving source (not shown). The second guide plate 5 has flange portions 5a and 5b bent outward at its opposite ends. Guide holes are formed in the flange portions 5a and 5b. Bolts 15 are implanted on the support plate 7 and project inward toward guide plates 3. The guide holes formed in the flange portions 5a and 5b of the second guide plate 5 each have a diameter slightly larger than that of the bolts 15. Thus, bolts 15 pass through guide holes 5a and 5b, respectively. Springs 13 interposed between the flange portions 5a and 5b and the support plate 7 urge the second guide plate 5 away from the support plate 7 so that the flange portions 5a and 5b abut against head portions of the bolts 15. Thus, the paper conveying path 4 having the predetermined space t is formed between the first and second guide plates 3 and 5 when the support plate 7 is in the closed position. Guide pieces 5c and 5d project from the flange portions 5a and 5b and are guided in the guide holes 3c and 3d formed in the first guide plates 3. Therefore, if the support plate 7 and/or door 45 slants relative to the deck body 25, the guide pieces 5c and 5d of the second guide plate 5 always correctly align the second guide plate 5 relative to the first guide plates 3. Accordingly, slant feeding of the paper can effectively be prevented. In the paper conveying path 4, the small-diameter follower rollers 9 are elastically supported on the support plate 7 by springs 12 and oppose the large-diameter rotationally driven conveying rollers 8 when the support plate 7 is in the closed position. The springs 12 urge the follower rollers 9 toward the conveying rollers to contact the conveying rollers 8. The conveying rollers 8 are driven to rotate at fixed positions in the paper conveying paths 4. As shown in Fig. 2, a pair of support brackets 18 are formed on the support plate 7 at its inner side and project inward toward the guide plates 3 when the support plate 7 is in the closed position. Bearings 11 for supporting the support shaft 10 of the follower rollers 9 are held by the springs 12 suspended between the opposite shoulder portions of the brackets 18. Guide brackets 19 for guiding the bearings 11 respectively are formed on the second guide plate 5 and project outward. Vertical grooves (not shown) in which inside edges of the guide brackets 19 are loosely inserted are formed in the bearings 11 at their front and rear sides, respectively. Because of this configuration, the springs 12 urge follower rollers 9 toward the conveying rollers 8 without being influenced by the forces exerted on the second guide plate 5 by springs 13. That is, the springs 12 for urging the follower rollers and the springs 13 for urging the second guide plate 5 do not interfere with each other. Thus, the respective spring forces of the springs 12 and 13 can be selected to have suitable values independently of each other. Accordingly, the spring force of the springs 13 for urging the second guide plate 5 can be selected to be a value relatively weaker than that in the conventional apparatus, and the hooking force of the lock mechanism 14 can be small thus allowing the door 45 to be locked and unlocked easily to facilitate opening and closing.

Claims: A paper conveying apparatus comprising: first and second guide plates (3; 5) having first and second openings therein, respectively; a support plate (7) for the second guide plate (5), movable between a first and second position, for positioning the second guide plate (5) at the first position where the second guide plate (5) is substantially parallel to the first guide plate (3) and the second position different from the first position, the first and second guide plates (3; 5) forming a paper conveying path when the second guide plate (5) is at the first position; at least one conveying roller (8) projecting into the paper conveying path (4) through the first opening in the first guide plate (3); at least one follower roller (9) projecting into the paper conveying path (4) through the second opening in the second guide plate (5); first means (13) for urging the second guide plate (5) away from the support plate (7), the first urging means (13) positioning the second guide plate (5) at a predetermined distance away from the first guide plate (3) when the support plate (7) is at the first position; and second means (12) for urging the at least one follower roller (9) toward the at least one conveying roller (8), characterized in that the second urging means (12) is attached to the support plate (7) such that the at least one follower roller (9) is independently movable with respect to the second guide plate (5). A paper conveying apparatus as claimed in claim 1, wherein the second urging means (12) further comprises: at least one first projection (18) extending from the support plate (7); and elastic means (12), coupled to the at least one first projection (18), for supporting the follower roller (9); wherein at least one second projection (19) extends from the second guide plate (5); and wherein the first and second projections (18; 19) and the elastic means (12) cooperate to project the follower roller (9) through the second opening. A paper conveying apparatus as claimed in claim 2, further comprising: a bearing (11); and a first shaft (10) coupled to the follower roller (9) and the bearing (11) and projecting in a rotational axial direction therefrom; the first and second projections (18; 19), the elastic means (12) and the bearing (11) cooperating to project the follower roller (9) through the second opening. A paper conveying apparatus as claimed in claim 1, further comprising first and second bolts (15) secured to the support plate (7), the first and second bolts (15) each having an extended portion and a flange at one end thereof; and wherein the second guide plate (5) has first and second holes (5a; 5b) therein, the extended portion of the first and second bolts (15) passing through the first and second holes (5a; 5b), respectively; and the first urging means (13) comprises elastic means, the elastic means urging the second guide plate (5) to abut against the flanges of the first and second bolts (15) to position the second guide plate (5) at the predetermined distance away from the first guide plate (3). A paper conveying apparatus as claimed in claim 1, further comprising: first and second side plates (27; 26), the first guide plate (3) being secured to the first and second side plates (27; 26) and the support plate (7) being pivotally secured to the first side plate (27); and means (14) for removably locking the support plate (7) to the second side plate (26) when the support plate (7) is at the first position. A paper conveying apparatus as claimed in claim 3, wherein the bearing (11) has first and second grooves therein and portions of the first and second projections (18; 19) nest in the first and second grooves, respectively. A paper conveying apparatus as claimed in claim 1, wherein: the first guide plate (3) has first guide holes (3c; 3d) therein; and the second guide plate (5) has first guide projections (5c; 5d) extending therefrom; the first guide projections (5c; 5d) cooperating with the first guide holes (3c; 3d) to align the first and second guide plates (3; 5). A paper conveying apparatus as claimed in claim 5, wherein; the support plate (7) has a locking projection (14b) extending therefrom; and the second side plate (26) has a locking opening (14a), the locking projection (14b) cooperating with the locking opening (14a) to removably lock the support plate (7) to the second side plate (26). A paper conveying apparatus as claimed in claim 1, further comprising a plurality of said follower rollers (9) and a plurality of said conveying rollers (8).

Inventors: MORITA TAKAKAZU, MORITA, TAKAKAZU
Applicants: MITA INDUSTRIAL CO LTD, MITA INDUSTRIAL CO. LTD.
Application year: 1992
Main classification: B65H5
IPC codes: B65H5, G03G15