JP2639872B2 - Driven roller support structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a driven roller supporting structure in a device for conveying a sheet such as a recording sheet or a bill to a predetermined position by rotating a driven roller and a driven roller pressed against the driven roller.

2. Description of the Related Art In a recording apparatus such as a copying machine or a printer, a recording sheet is conveyed to a predetermined position by a driving roller and a driven roller which rotates while being pressed against the driving roller. In the automatic cash processing apparatus, bills are conveyed by the rotation of the driven and driven rollers. In either case, the driven roller comes into pressure contact with the driven roller so as to be retractable.

[0003]

2. Description of the Related Art FIG. 11 is a side view showing an outline of the structure of a conventional double-sided printing apparatus which conveys a recording sheet to a predetermined position by rotation of a driving roller and a driven roller as described above. Reference numeral 9 denotes a paper cassette, 10 denotes a paper feed unit, 11 denotes a positioning roller, 13 denotes a fixing device, 21 denotes a conveyance path for backside printing, and 24 denotes a discharge conveyance path.

Around the photosensitive drum 1, an exposing unit 2, a developing unit 3, a transfer unit 4 provided with a peeling charger 12, a cleaner 5,
A uniform charger 6 is arranged, and an optical system unit 7 is arranged above the photoconductor 1. The fixing device 13 includes the heat roller 1
The heat roller 13a includes a heat source (not shown).

[0005] Along the back printing path 21, the base 2
7, a frame 29 supported on the base 27 via a support shaft 28, a guide member 30 supported on the frame 29 so as to be openable and closable, and a guide member 31 supported on the base 27 so as to be openable and closable. And frame 29, base 2
On the 7th side, the opposing roller 20 and the transport roller 25 on the driving side
a, 22a and 23a, and driven rollers 25b, 22b and 23b are provided on the guide members 30 and 31 side, respectively. The frame 29 is normally positioned in the illustrated inclined state. The guide members 30 and 31 are normally closed in the state shown in the figure, and the paper passes between the closed guide members 30 and 31 and the frame 29 and the base 27 and passes through the transport rollers 25a, 22a and 23a. The sheet is conveyed by driven rollers 25b, 22b, and 23b that press against these.

At the time of printing, the photosensitive drum 1 is rotated clockwise as indicated by an arrow, and its surface is uniformly charged by a uniform charger 6, and then the surface is irradiated with the information light 8 from the optical system unit 7. Exposure is performed by irradiating the exposure unit 2. Thus, an electrostatic latent image is formed on the surface of the photosensitive drum 1. This electrostatic latent image is developed by the developing device 3 to become a toner image.

On the other hand, the sheet-like sheet stored in the sheet cassette 9 is fed out by a pick roller 9 a and sent to a positioning roller 11 through a sheet feeding unit 10. Here, the sheet is sent to a transfer position between the photosensitive drum 1 and the transfer unit 4 at the same timing as the toner image formation, with the leading ends thereof aligned. At the transfer position, the toner image on the photosensitive drum 1 is transferred onto the sheet by the transfer device, and then the sheet is separated from the photosensitive drum 1 by the separation charger 12.

[0008] The sheet peeled off from the photosensitive drum 1 enters between the two rollers of the fixing device 13, where the heat roller 13a
After the toner image is fixed by the heating by the pressure roller and the pressure by the pressure roller 13b, the toner image is conveyed by the impeller 14 and the opposing roller 15. In the case of single-sided recording, the sheet is conveyed upward by the forward / reverse rollers 16, 17, 18 rotating forward and discharged to the sheet discharge tray 19.

In the case of double-sided recording, the paper that has passed between the impeller 14 and the opposing roller 15 is initially conveyed upward by forward and reverse rotation rollers 16, 17, and 18, but the rear end of the paper Are conveyed downward by the forward / reverse rollers 16, 17 and 18 which reverse when a predetermined time elapses after being detected by the sensor 26, and are conveyed in the conveyance path 21 for back side printing to the conveyance rollers 25a, 22a and 23a and It is conveyed by the driven rollers 25b, 22b, and 23b that are in pressure contact.
It should be noted that a plurality of pairs of each transport roller and a driven roller that comes into pressure contact with the transport roller are provided in a direction perpendicular to the paper surface of FIG.

The paper that has passed between the rollers of the back-side printing transport path 21 is sent to the positioning roller 11 again with the front and back reversed, and during this time, the formation of the back-side toner image on the surface of the photosensitive drum 1 proceeds. . Thereafter, the toner image is transferred and fixed on the back surface of the sheet in the same procedure as described above. Thereafter, the sheet is discharged to a sheet discharge tray 19 by forward and reverse rotation rollers 16, 17, and 18 which rotate forward and backward.

In this case, as shown in FIG. 12, when the second sheet S2, which has been printed on only one side, is running in front of the first sheet S1 on which printing on the back side is running, the first sheet S1 Is obstructed when is printed on the paper output tray after the back side printing is completed. That is, when the toner image is transferred and fixed by the transfer device 4, the first sheet S1 is conveyed toward the discharge tray, but the second sheet S2 in front of the first sheet S1 is
After being conveyed in the discharge direction until the rear end passes through the impeller 14, it is retracted toward the back-side printing conveyance path 21 by the reverse rotation of the forward / reverse rollers 16, 17, 18.

Therefore, the second seat S traveling forward is
Unless the sheet 2 has completely retreated into the back-side printing transport path 21, the first sheet S1 that has been subjected to the duplex printing cannot travel on the discharge / delivery path 24 toward the discharge tray. Therefore, in reality, after the second sheet S2 on which single-sided printing has been completed is completely retracted into the back-side printing conveyance path 21 as indicated by a chain line S2 ', the leading end of the first sheet S1 on which double-sided printing has been completed is Impeller 1
4 and the second sheet S to such an extent that
2 and the first sheet S1 are spaced apart. That is,
When the second sheet S2 after the single-sided printing is present at the position indicated by the solid line in FIG. 12, the first sheet S2 for the back side printing is used.
No. 1 is traveling in the rear-surface printing conveyance path 21 far away at least by the sheet length.

For this reason, the printing speed is reduced, and the discharge of the first sheet S1 which has been printed on both sides is delayed. In addition, if the first sheet S1 that has been subjected to double-sided printing is running inside the apparatus without being quickly discharged, the number of sheets staying inside the apparatus increases, and the sheet at the time of a paper jam (jam) occurs. The exclusion process becomes complicated.

In order to solve this problem, it is effective to transport the second sheet S2 to the reverse-side printing transport path 21 at a speed higher than the transport speed in the discharge direction and retract the second sheet S2. The peripheral speed at the time of reverse rotation of the rollers 16, 17, 18 is
What is necessary is just to make it faster than the peripheral speed at the time of normal rotation. Thus, the printing speed can be improved by shortening the interval between the sheets. Further, since the number of sheets in the apparatus is also reduced, the work of removing jammed paper becomes easy.

When the jammed paper is removed, the frame 29 is rotated counterclockwise as indicated by an arrow from the inclined state in FIG. 11 to a horizontal state. In this state, each guide member 30,
When the base 31 is opened, a sufficient space is formed on the frame 29 and the base 27, and it becomes possible to easily remove the jammed paper.

A conventional support structure of each driven roller disposed along the back-side printing transport path 21 and pressed against each of the transport rollers 25a, 22a and 23a will be described with reference to FIGS. The explanation is as follows.

FIG. 13 is an explanatory view of a supporting structure of the driven roller 23b (FIG. 13 (A) is a plan view, and FIG. 13 (B) is a side view).
In the drawing, reference numeral 32 denotes a guide member which faces the guide member 31 and constitutes the conveyance path 21 for back side printing, and 33 denotes a pressing spring. The shaft 34 of the driven roller 23b is
And is vertically movably supported by a bearing 35 provided therein, and is axially locked by a retaining ring 36. Driven roller 23b
Both ends are locked by locking pieces 31 a provided on the guide member 31, and are urged by a pressing spring 33 pressing the shaft 34 to be in pressure contact with the transport roller 23 a.

When the driven roller 23b is mounted,
As shown in FIG. 4, the driven roller 23b is fitted into the hole 31b of the guide member 31, and the shaft 34 inserted through the bearing 35 is fitted into the shaft hole.
Is locked in the axial direction, and finally, one end is
The other end of the pressing spring 33 to be locked to the other locking piece 31
and the mounting is completed.

[0019]

However, a plurality of sets of each conveying roller and a driven roller pressed against the conveying roller are provided in the axial direction (perpendicular to the plane of FIG. 11). Since it is necessary to perform the same operation and the number of parts is large, the assembling work is very troublesome, and a solution to the problem is strongly desired.

An object of the present invention is to provide a driven roller supporting structure which has a small number of parts and is easy to assemble.

[0021]

In order to achieve the above object, according to the present invention, a plate-like biasing means is mounted on a shaft supported by a plurality of bearings provided on a guide member so as to advance and retreat. In a supporting structure of a driven roller that is urged and pressed against a transport roller on a driving side, a ring-shaped first groove and a second groove are provided on the shaft, and the first groove is attached to the driven roller at the time of mounting. An engaging portion that elastically engages with the groove, the shaft fitting and supporting opening in each of the bearings,
A retaining portion for engaging the second groove and locking the shaft in the circumferential direction and the axial direction is provided on the guide member, and a holding portion for removably holding the urging means is provided on the guide member. And a positioning portion for positioning the biasing means, wherein the shaft is
The driven roller is mounted in the opening of the bearing with the driven roller mounted and locked by the locking portion, and the driven roller is held by the holding portion and the positioning portion, and the driven roller is moved by the biasing means. A configuration characterized by being urged so as to be in pressure contact with the transport roller (first configuration)
And

Further, in the driven roller support structure of the first configuration, an operating portion for engaging and disengaging is formed in the biasing means, and a hole for inserting a wire is formed in the operating portion. Configuration (second configuration).

[0023]

The driven roller is engaged with the shaft so as to be able to be engaged and disengaged and rotates, and the shaft is locked in the circumferential direction and the axial direction by the bearing on the guide member side, and moves forward and backward in the direction toward the transport roller. Supported as possible. The biasing unit is supported by the holding unit and is positioned by the positioning unit, and biases the shaft to press the driven roller against the transport roller.

As described above, according to the present invention, the number of components is small and the device can be manufactured at low cost. Further, the driven roller can be easily mounted on the shaft, and the shaft can be fitted and supported in the opening of the bearing with the driven roller mounted, thereby facilitating the assembly. Further, in the case of the second configuration, assembling is further facilitated by inserting the wire into the hole formed in the operating portion of the urging means and operating the wire.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 is a plan view showing a driven roller supporting structure of the present embodiment, in which 41 is a shaft, 42 is a driven roller made of resin,
43 is a guide member, and 44 is a biasing means. The guide member 43 corresponds to the conventional guide member 31 and the like.

As shown in detail in FIG. 2A, the shaft 41 has a plurality of ring-shaped first grooves 4 formed in a predetermined arrangement.
5 and a plurality of second grooves 46.
6 has a half-moon shape as shown in FIG.

As shown in detail in FIG. 3 (FIG. 3 (A) is a front view, FIG. 3 (B) is a side view), the driven roller 42 has a claw-shaped engaging portion 47 having elasticity in the circumferential direction. Are provided at equal intervals. The driven roller 42 is mounted on the shaft 41,
At the time of mounting, as shown in FIG. 4 (A), it is fitted to the shaft 41 by utilizing the elasticity of the engaging portion 47 and pushed in the direction of the arrow, and the engaging portion 47 is pushed in the first direction as shown in FIG. 4 (B). 1 groove 45
And attached. In this mounting completed state, there is a gap of about 0.1 to 0.2 mm between the engaging portion 47 and the first groove 45, and the driven roller 42 is locked in the axial direction with respect to the shaft 41 and is rotatable. It is.

As shown in detail in FIG. 5 (FIG. 5 (A) is a side view and FIG. 5 (B) is a plan view),
A plurality of cutouts 48 for fitting the outer peripheral portions of the plurality of driven rollers 42 mounted on the pair 1, a pair of holding portions 49 for respectively holding the pair of biasing means 44 in a detachable manner, and And a pin (positioning portion) 50 for positioning the urging means 44 formed near the portion 49.

Bearings 51 and 52 are provided at two places (generally, a plurality of places) of the plurality of notches 48. As shown in detail in FIG. 6 (FIG. 6 (A) is a view taken in the direction of arrow B in FIG. 5 (B), FIG. 6 (B) is a view taken in the direction of arrow C in FIG. 5 (B)). The main body of the guide member 43 is bent and formed integrally around the notch 48, and has openings 53 and 54 for fitting and supporting the shaft 41. The opening 53 is for supporting the shaft 41 so that it can advance and retreat. The opening 54 is provided on the shaft 41.
To be able to advance and retreat, and to lock the shaft 41 in the circumferential direction and the axial direction.

The shaft 41 on which the driven roller 42 is mounted as described above is fitted to a part of the outer periphery of each driven roller and each notch 48 and mounted on the guide member 43 as shown in FIG. At this time, the shaft 41 is supported by the bearings 51 and 52, and is engaged in the circumferential direction and the axial direction by engagement of the locking portion 55 (see FIG. 6B) of the bearing 52 with the second groove 46. Locked. 8A and 8B are explanatory diagrams of a state in which the shaft 41 is locked by the bearing 52. FIG. 8A is a plan view, and FIG.
It is -D sectional drawing.

Further, the holding section 49 is provided with the EE of FIG. 5B.
It has a shape shown in FIG. 9 which is a cross-sectional view, and its height h is a dimension to which the urging means 44 fits without rattling.

The biasing means 44 is a leaf spring having a positioning hole 56 for pin fitting, and as shown in FIG.
3 and the tip 57 presses the shaft 41 mounted on the guide member 43 as described above. Urging means 4
The mounting procedure of 4 is as shown in FIG. 10, and in mounting, the urging means 44 is moved in the direction of the arrow in the vicinity of the locking portion 49 as shown in FIG. As a result, the urging means 44 is moved to the locking portion 4 as shown in FIG.
9, the positioning hole 56 is fitted to the pin 50 and is removably positioned and held. Thus, the assembly is completed.

At the end of the biasing means 44, an operation portion 58 inclined upward by about 22 ° is formed. By operating the operation portion 58, the mounting operation is facilitated. Further, if a hole 59 is provided in the operation portion 58 and the wire is inserted into the hole 59 and the wire is operated, the mounting operation is further facilitated. Further, the guide member 4 is provided around the holding portion 49.
If the notch 60 (see FIGS. 1 and 10) is formed in 3, the engagement and disengagement of the urging means 44 is further facilitated.

As described above, the driven roller is supported on the shaft,
The operation of mounting the shaft on the guide member and the operation of attaching the urging means for urging the shaft to the guide member are easy, and the number of assembly steps is reduced. Also, the number of parts is small. The driven roller assembled as described above is urged by an urging means via a shaft, and presses against the conveyance roller on the driving side to play the role of conveying the recording medium.

[0036]

As described above, according to the present invention, the following various excellent effects can be obtained. (1) The number of parts is small. (2) Easy assembly. (3) Inexpensive.

[Brief description of the drawings]

FIG. 1 is a plan view showing a driven roller support structure according to an embodiment of the present invention.

FIG. 2 is a structural explanatory view of a shaft according to an embodiment of the present invention;
2A is a plan view, and FIG. 2B is a cross-sectional view taken along line AA of FIG.

FIG. 3 is a structural explanatory view of a driven roller according to an embodiment of the present invention;
FIG. 3A is a front view, and FIG. 3B is a side view.

4A and 4B are explanatory diagrams of a procedure for mounting a driven roller according to an embodiment of the present invention. FIG.
(B) shows the driven roller mounting completed state.

FIG. 5 is a structural explanatory view of a guide member according to the embodiment of the present invention;
FIG. 5A is a side view, and FIG. 5B is a plan view.

6 is a structural explanatory view of each bearing according to the embodiment of the present invention.
(A) is a view on arrow B in FIG. 5 (B), and FIG. 6 (B) is a view in FIG.
It is the arrow C view of (B).

FIG. 7 is a plan view showing a state where the shaft is mounted on the guide member according to the embodiment of the present invention.

8A and 8B are explanatory views of a shaft locking state by a bearing on a locking side according to an embodiment of the present invention. FIG. 8A is a plan view, and FIG.
It is DD sectional drawing of (A).

FIG. 9 is a sectional view taken along line EE of FIG. 5 (B).

10A and 10B are explanatory diagrams of the urging means mounting procedure according to the embodiment of the present invention. FIG. 10A shows the urging means mounting start state, and FIG. 10B shows the urging means mounting completed state. .

And FIG. 11 is a side view showing a structural outline of a conventional double-sided printing apparatus.

FIG. 12 is an explanatory view of a seat traveling state in a conventional device.

FIG. 13 is an explanatory view of a conventional driven roller support structure.

14 is an explanatory diagram of a mounting procedure of the driven roller support structure of FIG.

[Explanation of symbols]

 41 shaft 42 driven roller 43 guide member 44 urging means 45 first groove 46 second groove 47 engaging part 49 holding part 50 pin (positioning part) 51, 52 bearing 55 locking part 56 positioning hole 58 operation part 59 Hole for wire insertion

Claims (2)

(57) [Claims] A shaft (4) supported by a plurality of bearings (51, 52) provided on a guide member (43) so as to be able to advance and retreat.
In a supporting structure of a driven roller (42) which is rotatably mounted on 1) and is urged by a plate-shaped urging means (44) and pressed against a transport roller on the driving side, a ring is provided on the shaft (41). A first groove (45) and a second groove (46) are provided, and the driven roller (42) is provided with an engaging portion (47) that elastically engages with the first groove (45). The bearings (51, 52) are provided with openings (53, 54) for fitting and supporting the shaft (41), and the bearings (52) are provided with the second grooves (46). The engaging portion (5) which engages and locks the shaft (41) in the circumferential direction and the axial direction.
5), the guide member (43) has a holding portion (49) for detachably holding the urging means (44), and a positioning portion (50) for positioning the urging means (44). The shaft (41) is provided with the driven roller (42) in a state where the driven portion (47) is mounted by engaging the engaging portion (47) with the first groove (45). , 52) opening (53, 5)
4) The inside of the driven roller (44) by the urging means (44), which is mounted inside and locked by the locking portion (55) and held and positioned by the holding portion (49) and the positioning portion (50). 42) a driven roller supporting structure, wherein the driven roller is biased so as to press against the transport roller. 2. An operating portion (58) for engaging and disengaging operation is formed in the biasing means (44), and a hole for inserting a wire is formed in the operating portion (58). The driven roller supporting structure according to the above.