JP2844335B2 - Paper feeder - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper feeder for feeding paper (continuous paper) to various printers and computers. 2. Description of the Related Art Conventionally, this type of paper feeder has been disclosed in, for example, Japanese Utility Model Laid-Open No. 60-94960 and Japanese Utility Model Laid-Open No. 59-1647.
There is one disclosed in Japanese Patent Publication No. 44-44. Further, in such a paper feeder, an endless feed belt is mounted between a drive pulley disposed between a pair of side frames and a belt guide. Then, in a state in which the feed pins on the outer periphery of the feed belt are engaged with the feed holes of the paper, the outer teeth on the outer periphery of the drive pulley travel in an arc along the outer periphery of the drive pulley. By rotating while meshing with the internal teeth of the side arc-shaped running portion), the feed belt is driven in a predetermined direction to transfer the paper. However, in the above-described conventional apparatus, an external force larger than the meshing force between the internal teeth of the driving-side circular running portion of the feed belt and the external teeth of the driving pulley is generated. When the paper is loaded, the driving-side arc-shaped traveling portion of the feed belt floats with respect to the driving pulley, causing problems such as slippage and belt jumping. According to the present invention, there is provided a frame comprising at least a pair of side frames, and disposed between the pair of side frames near one end of the frame to be rotatable about the side frames. And a drive pulley having external teeth formed on the outer peripheral edge thereof, and internal teeth meshing with the external teeth of the drive pulley formed on the inner peripheral surface, and a feed pin projecting from the outer peripheral surface with a predetermined pitch. It is formed in the shape of an endless belt, and runs between the pair of side frames along the outer peripheral surface on one side of the drive pulley where the internal teeth mesh with the external teeth of the drive pulley and the guide surface of a belt guide provided on the frame. In the paper feeder having a feed belt to be restrained, the feed belt is prevented from floating from the outer peripheral surface of the drive pulley, and the meshing state between the external teeth of the drive belt and the internal teeth of the feed belt is maintained. The purpose is to tighten. According to the present invention, in the paper feeder, the feed belt meshes with one of the pair of side frames and engages with the drive pulley along one outer peripheral surface of the drive pulley. At the outer peripheral position of the driving-side arc-shaped traveling path to be driven, a belt regulating piece having an inner surface having a smooth cylindrical surface in cross section along the driving-side arc-shaped traveling path is formed, and the feed belt is formed. In the state of being meshed with the external teeth of the drive pulley by the internal teeth, the distance between the tip of the feed pin of the feed belt and the smooth cylindrical surface having the arc-shaped cross section formed on the belt regulating piece,
The internal teeth formed on the feed belt are smaller than the meshing dimensions of the internal teeth formed on the drive pulley with respect to the external teeth formed on the drive pulley. The paper feeder is formed in an endless belt shape, a part of which is meshed with the drive pulley, and the remaining part is along the guide surface of the belt guide provided on the frame. When the drive pulley is driven to rotate, the feed belt moves in the longitudinal direction due to the engagement between the internal teeth formed on the inner peripheral surface of the feed belt and the external teeth formed on the outer peripheral edge of the drive pulley. The inner surface of the drive pulley travels along a drive-side arc-shaped travel path along one outer peripheral surface of the drive pulley meshing with the outer teeth of the drive pulley, and a guide surface of a belt guide provided on the frame. Can be run endlessly along the road along the road. Along with this, a feed pin protruding from a linear running portion of the feed belt that runs along the guide surface of the belt guide formed linearly among the belt guides has a side edge portion of the paper. Along the feed pins arranged in the same pitch as the pitch of the feed pins, and feeds the paper to a printer or computer. At this time, when an external force greater than the meshing force between the external teeth of the drive pulley and the internal teeth of the feed belt is applied to the sheet, the portion of the feed belt located in the drive-side arc-shaped traveling portion is driven by the drive belt. It tends to float with respect to the pulley. In the driving-side arc-shaped traveling portion, the feed belt is driven so that the internal teeth formed on the feed belt mesh with the external teeth formed on the driving pulley, and travel along the driving-side arc-shaped traveling portion. However, when the floating amount of the feed belt is larger than the engagement dimension of the internal teeth of the feed belt with the external teeth of the drive pulley, the internal teeth of the feed belt are released from the engagement with the external teeth of the drive pulley. Slip of the feed belt with respect to the drive pulley occurs, causing a state in which the drive torque of the drive pulley is not transmitted to the feed belt. It hinders the durability of the paper feeder. In the present invention, one of the pair of side frames has an inner surface at an outer peripheral position of the driving-side arc-shaped traveling path, and an inner side surface having an arc-shaped cross section along the driving-side arc-shaped traveling path. As described above, when the sheet is fed as described above, a large external force is applied to the sheet by the meshing force between the external teeth of the driving pulley and the internal teeth of the feed belt. When the load is applied and the portion of the feed belt located on the drive-side arc-shaped traveling path tends to float with respect to the drive pulley, the tip of the feed pin protruding from the outer peripheral surface of the feed belt is It collides with a smooth cylindrical surface having an arc-shaped cross section formed on the inner surface of the belt regulating piece, and further lifting of the feed belt is prevented. The belt restricting piece is formed only on one side frame of the pair of side frames, and the inner side surface has an arc-shaped smooth cylindrical surface along the driving side arc-shaped traveling path of the feed belt. As a result, the feed belt does not hinder the travel of the feed belt or paper, and does not restrict the travel of the leading end of the feed pin. In a state where the feed belt is meshed with the external teeth of the drive pulley by its internal teeth, the tip of the feed pin and the inside of the belt restricting piece whose cross section is an arc-shaped smooth cylindrical surface. The distance between the side of the feed belt located on the drive-side arc-shaped travel path is set by setting the interval between the side and the side of the feed belt to be smaller than the meshing dimension of the internal teeth formed on the feed belt with the external teeth formed on the drive pulley. Since the floating amount is limited to be smaller than the meshing dimension of the internal teeth with the external teeth, the internal teeth of the feed belt are not released from the meshing state with the external teeth of the driving pulley. The occurrence of belt slippage is prevented, and the occurrence of belt jumping is also prevented. Therefore, according to the present invention, when the feed belt is driven by the driving pulley to drive the feed belt, an external force greater than the meshing force between the external teeth of the drive pulley and the internal teeth of the feed belt is generated. Even when the paper is loaded, the lifting of the feed belt with respect to the drive pulley is prevented, and the meshing state between the internal teeth of the portion of the feed belt located on the drive-side circular running path and the external teeth of the drive pulley is maintained. , The driving torque of the driving pulley can be reliably transmitted to the feed belt,
Furthermore, since the frictional resistance due to the collision between the tip of the feed pin provided on the feed belt and the smooth cylindrical surface having a circular arc-shaped cross section, which is the inner surface of the restricting piece, is small, when the feed belt is prevented from floating, Also has low driving resistance to the driving pulley,
In addition, belt jumping can be prevented, and the durability of the paper feeder can be improved. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a first embodiment of the present invention; FIG. 1 is an exploded perspective view of the paper feeder in which the paper feeder of the embodiment is disassembled into parts before assembly, and the configuration of each part and the relationship between the parts are shown. FIG. 3 is a side sectional view of the paper feeder to which each part is assembled, and FIG. 3 is a plan view thereof. In the figure, a frame 8 of the paper feeder includes a pair of side frames 9 and 10 and a pair of side frames 9 and 1.
The three members of the belt guide 11, which are disposed between zero, are assembled as described later. Bearing holes 15 and 16 are formed near one ends of the pair of side frames 9 and 10 so as to be centered on the same central axis, and a driving pulley 17 is inserted through these bearing holes 15 and 16.
The boss 18 is rotatably supported on the outer peripheral surfaces at both ends in the axial direction, and a large-diameter pulley 21 is provided at the center of the outer peripheral surface of the boss 18 concentrically with the boss 18 and the pair of the bosses 18. External teeth 22 are formed at equal intervals on the outer peripheral surface of the pulley portion 21. The feed belt 1 is formed in an endless belt shape on the inner peripheral surface of which the internal teeth 7 meshing with the external teeth 22 formed on the pulley portion 21 of the drive pulley 17 are formed.
7 and the frame 8 are wrapped around the peripheral surface of the belt guide 11. The drive pulley 17 has the boss 18
A square hole 19 having a square cross section centered on the center axis of the drive shaft 2 is formed through the square hole 19.
0 is slidably fitted as densely as possible. The drive shaft 20 is rotated by a prime mover (not shown) and drives the drive pulley 17. When the drive pulley 17 is driven to rotate by the drive shaft 20, the drive pulley 17 is caused to travel along one outer peripheral surface of the drive pulley 17 by engagement of the internal teeth 7 and the external teeth 22 of the drive pulley 17, The belt guide 11 is caused to travel along a linear guide surface formed on the belt guide 11 and an arc-shaped guide surface located at a position opposite to the drive pulley 17 in the longitudinal direction. In the outer peripheral surface of the feed belt 1, in a central portion of the belt width, feed holes are arranged in a line at predetermined pitches in a straight line along a side edge of a sheet (not shown) to be fed. Corresponding, predetermined number of feed pins 6 are projected in a straight line with the same pitch as the predetermined pitch. Here, in order to facilitate the description of the running state of the feed belt 1, the inner teeth 7 of the feed belt 1 mesh with the outer teeth 22 of the drive pulley 17, and A traveling path traveling along the traveling path is referred to as a driving-side circular traveling path, and a portion of the feed belt 1 located at a position traveling along the traveling path is referred to as a driving-side circular traveling section 2, and a guide surface 11 a formed on the belt guide 11. Of these, the traveling path of the feed belt 1 traveling along the arc-shaped guide surface is referred to as a driven-side arc traveling path, and the portion of the feed belt 1 at a position traveling on the traveling path is referred to as a driven-side arc traveling section 3. The traveling path of the feed belt 1 that travels along one linear guide surface among the guide surfaces 11a formed on the belt guide 11 and travels while engaging the feed pin 6 with the paper feed hole. Linear paper feed travel , The feed belt 1 which runs the 該走 path
Is referred to as a linear paper feed traveling section 4, and the portion of the feed belt 1 traveling on a traveling path along the other linear guide surface is referred to as a linear traveling section 5. The feed belt 1 shown in FIG.
5 is shown. A pair of front and rear connecting claws 1 are provided on opposing surfaces of the two side frames 9 and 10.
The belt guide 11 is formed with a square hole-shaped locking hole 14 that elastically engages with each of the connecting claws 12, 13. Then, the connecting claws 12 and 13 of the both-side frames 9 and 10 are elastically engaged and disengaged with the locking holes 14 of the belt guide 11, respectively, so that these three members are integrally connected. Of the two side frames 9, 10, one side edge of one side frame 9 is opposed to the tip of the feed pin 6 on the outer periphery of the driving-side arc-shaped running portion 2 of the feed belt 1 with a slight gap. An arc-shaped belt restricting piece 23 for preventing the drive-side arc-shaped traveling portion 2 from floating is formed. The belt restricting piece 23 has its arc range set so that at least one feed pin 6 is located in the driving-side arc-shaped traveling portion 2 of the feed belt 1. A smooth cylindrical surface 23a having an arc-shaped cross section is formed on the inner surface facing the side arc-shaped traveling portion 2, and the smooth cylindrical surface 23a and feed pins 6 protruding from the outer peripheral surface of the feed belt 1 are formed. When the feed belt 1 is engaged with the external teeth 22 formed on the pulley portion 21 of the drive pulley 17 by the internal teeth 7 of the feed belt 1, the internal teeth 7 of the feed belt 1 are External teeth 2
The interval is smaller than the meshing dimension for 2. The driving-side arc-shaped traveling portion 2 of the feed belt 1
, The feed belt 1 runs on a cylindrical surface around the rotation center axis of the drive pulley 17 along one outer peripheral edge of the drive pulley 17, and accordingly, the leading end of the feed pin 6 is 17 travels in a plane perpendicular to the rotation center axis of the cylinder 17.
a is a smooth cylindrical surface having a circular cross section in a plane perpendicular to the rotation center axis of the drive pulley 17 on which the feed pin 6 of the feed belt 1 travels, so that the feed belt 1 can be lifted up. The tip of the feed pin 6 and the cylindrical surface 2
The contact with the belt 3a is stabilized with little frictional resistance therebetween, and the engagement between the internal teeth 7 of the feed belt 1 and the external teeth 22 formed on the pulley portion 21 of the driving pulley 17 is ensured. In this embodiment, as shown in FIG. 2, the length of the belt regulating piece 23 along the arc of the smooth cylindrical surface 23 a having the arc-shaped cross section is determined by the length of the feed pin 6 adjacent to the feed belt 1.
Is formed to be appropriately longer than the interval. The driven-side circular running portion 3 of the feed belt 1
Of the belt guide 11 at the portion forming the driven-side arc-shaped travel path of the feed belt and the linear paper feed travel portion 4 of the feed belt 1 and the linear paper of the feed belt. The linear guide surface 11a of the belt guide 11 at the portion forming the feed travel path and the guide surface 11a at the portion forming the linear travel path of the feed belt by supporting the linear travel portion 5 of the feed belt 1 are respectively provided. Feed belt 1
At a position corresponding to the feed pin, the width W of the guide surface 11a is substantially equal to the diameter D of the feed pin 6 as shown in FIG. The frictional force generated between the inner surface of the feed belt 1 and the guide surface 11a of the belt guide 11 is reduced. The front and rear portions of both sides of the belt guide 11 have their tips abutting against the opposing surfaces of the both-side frames 9 and 10, respectively, so that the guide surface 11a of the belt guide 11 is A predetermined number of holding pins 11b for holding at corresponding positions protrude. further,
A belt guide 1 that supports a driven-side arc-shaped traveling portion 3 of a feed belt 1 on a guide surface 11 a of the belt guide 11.
A portion of the guide surface 11a of the arcuate guide surface and a portion of the linear guide surface of the guide surface 11a supporting the linear paper feed travel portion 4 and the linear travel portion 5 of the feed belt 1. And the escape groove 11c having a predetermined length
Is formed, and the contact area with the inner surface of the feed belt 1 is reduced. Further, a belt support surface 9a formed on the upper and lower portions of the opposing surfaces of the pair of side frames 9, 10 and supporting the side edges of the linear paper feed traveling portion 4 and the linear traveling portion 5 of the feed belt 1. , 10a, the portions facing the substantially central portions of the two linear running portions 4 and 5 of the feed belt 1 are cut as shown in FIG. 1 so as not to contact the side edges of the feed belt 1. Notched escape grooves 9c, 10c are formed in the front and rear directions of these side frames 9, 10. As a result, the belt supporting surfaces 9 of these side frames 9 and 10 are formed.
a, 10 a and the frictional force generated between the side edges of the feed belt 1 are reduced. A cylindrical boss portion 26 is formed substantially at the center of one of the pair of side frames 9 and 10 so as to be axially movably fitted to the support shaft 25. The other side frame 9 is provided with an upper opening box-shaped holding portion 27 having a lock lever 28 therein for removably restraining and holding the frame 8 at a desired position with respect to the support shaft 25. One side edge of the inner surface of the holding portion 27 is used as a restraining surface 27a of the lock lever 28. As shown in FIGS. 1, 3, 4 and 5, the lock lever 28 has a boss 29 having a center hole into which the support shaft 25 is inserted, and an outer peripheral surface of the boss 29. An operation handle 30 that is integrally provided is mainly configured. When the boss portion 29 is inserted through the upper opening of the holding portion 27 and the center hole is inserted into the support shaft 25, the operating handle 30 is manually operated through the opening portion of the holding portion 27. It is projected as possible. Further, a cam surface 31 whose radius of curvature is gradually increased in the counterclockwise direction in FIG. 4 with respect to the center of the support shaft 25 is formed on the outer peripheral surface of the boss portion 29 of the lock lever 28. The cam surface 31 is engaged with the restraining surface 27a of the holding portion 27 by the clockwise operation as shown in FIG.
Is locked at a desired position on the support shaft 25 so that sheets of different widths can be handled. A pair of front and rear bearing pieces 32 with respect to the paper holding plate 34 are provided above the outer side surface of the one side frame 9.
A hinge pin 35 integrally formed on one side of a paper holding plate 34 is rotatably fitted into a bearing hole 33 formed in the upper surface of the bearing piece 32. Then, the paper holding plate 34 has the hinge pin 3
Opening and closing around the center 5 and closing over the upper end surfaces of the pair of side frames 9 and 10, the floating of the sheet is prevented. Also, this paper holding plate 3
A tension spring 38 is interposed between the spring hooks 36 and 37 formed between the first frame 4 and one side frame 9, and the paper holding plate 34 is moved to the open position by the spring force of the tension spring 38. Each is biased to a closed position. A long groove 39 in the front-rear direction in which the feed pin 6 of the feed belt 1 is movable is provided through the paper holding plate 34. The paper feeder constructed as described above is provided so as to be able to move in the axial direction so as to straddle between the drive shaft 20 and the support shaft 25 in a left and right pair. The frames 9 and 10 on both sides, the belt guide 11 and the like are each formed of a synthetic resin. In particular, the belt guide 11 is formed of a synthetic resin material having a small coefficient of friction. As is well known, the drive shaft 20 and the support shaft 25 are installed in a frame on the printer or computer side, and the drive shaft 20 is driven to rotate by a drive unit having a motor as a drive source. In this embodiment configured as described above, the feed holes formed on the right and left sides of the paper are fitted into the feed pins 6 of the feed belt 1 provided in each of the pair of left and right paper feeders, With the paper holding plate 34 closed, the drive pulley 17 is rotated in a predetermined direction by the drive shaft 20 and the feed belt 1 is driven to feed the paper. When the feed belt 1 is driven, an external force greater than the meshing force between the internal teeth 7 of the drive-side arc-shaped running portion 2 of the feed belt 1 and the external teeth 22 of the drive pulley 17 is applied to the sheet. In this case, the drive-side arc-shaped traveling portion 2 of the feed belt 1 tends to float with respect to the external teeth 22 of the drive pulley 17. By abutting on the formed cylindrical surface 23a having an arc-shaped cross section, the lifting of the driving-side arc-shaped traveling portion 2 is restricted. The belt restricting piece is formed only on one of the side frames of the pair of side frames, and the inner side surface has an arc-shaped smooth cylindrical surface along the driving-side arc-shaped traveling path of the feed belt. Therefore, it does not hinder the running of the feed belt and the paper, and does not restrict the running of the tip of the feed pin. Therefore, the feed belt 1
Slip, belt jumping, and the like caused by the lifting of the driving-side arc-shaped traveling portion 2 of the feed belt 1 are reliably prevented.
The meshing between the internal teeth 7 of the driving-side arc-shaped traveling portion 2 and the external teeth 22 of the driving pulley 17 can be maintained. For this reason, the driving torque of the driving pulley 17 receives only a small frictional resistance between the tip of the feed pin 6 and the smooth cylindrical surface 23 a having the circular arc cross section, and is reliably applied to the driving-side circular running portion 2 of the feed belt 1. And transfer failure of the sheet can be prevented.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded perspective view of a paper feeder. FIG. 2 is a side sectional view. FIG. 3 is a plan sectional view. FIG. FIG. 5 is a sectional view showing a locked state. [Description of References] 1 Feed belt 2 Drive-side circular running section 3 Follower-side circular running section 4 Straight paper feed running section 5 Straight Traveling part 6 Feed pin 7 Internal teeth 8 Frames 9 and 10 Side frame 17 Drive pulley 22 External teeth 23 Belt regulating piece 23a Cylindrical cylindrical surface in cross section

Claims (1)

(57) [Claims] A frame composed of at least a pair of side frames,
A drive pulley disposed between the pair of side frames near one end of the frame, rotatably supported by the side frames, and having external teeth formed on an outer peripheral edge thereof; meshing with the external teeth of the drive pulley Internal teeth are formed on the inner peripheral surface, and feed pins are formed on the outer peripheral surface in an endless belt shape protruding with a predetermined pitch,
Between the pair of side frames, the inner teeth mesh with the outer teeth of the drive pulley, and a feed belt that is caused to travel along one outer peripheral surface of the drive pulley and a guide surface of a belt guide provided on the frame. A driving-side arc-shaped traveling path in which one of the pair of side frames meshes with the driving pulley and the feed belt runs along one outer peripheral surface of the driving pulley. At the outer peripheral position, a belt restricting piece whose inner surface is formed as a smooth cylindrical surface having an arc-shaped cross section along the driving-side arc-shaped traveling path, and the feed belt is formed outside the driving pulley by its internal teeth. In a state in which the belt is engaged with the teeth, the distance between the front end of the feed pin of the feed belt and the inner side surface of the belt restricting piece, which has the cross section formed as an arc-shaped smooth cylindrical surface, is set to the front. A paper feeder, wherein the internal teeth formed on the feed belt are smaller than the engagement dimension with the external teeth formed on the drive pulley.