JPH0725184B2 - Sheet transport device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a sheet conveying apparatus, and more particularly to a sheet conveying apparatus applied to a recording apparatus using fanfold paper.

[Prior Art] Conventionally, a paper feeding device as a sheet conveying device of this type is first
Shown in Figures and 2.

A platen roller denoted by reference numeral 1 in both drawings has a pulley 3 fixed to one end of its shaft 2.

The shaft 2 is rotatably supported by a side plate of a device (not shown).

A gear 5 is rotatably provided in the vicinity of the pulley 3, and a belt 4 is stretched between a pulley 5 and a shaft 5a protruding from one end of the gear 5.

Reference numeral 6 denotes a stepping motor, which meshes with a drive gear 7 fixed to the output shaft of the stepping motor 5.

Therefore, the rotation of the stepping motor 6 is reliably transmitted to the platen roller 1 via the gear and the belt.

A shaft 9 is laid horizontally on the front side of the platen roller 1 in parallel therewith, and a pinch roller 8 for pressing the paper is rotatably supported on the shaft 9.

Both ends of the shaft 9 are rotatably supported on the device side by lower parts thereof supported by rotatable arms 10 and 10 supported by a shaft 11.

These arms 10 and 10 are given a turning tendency toward the platen roller 1 by a torsion coil spring 12.

Behind the platen roller 1 are two shafts 14, 1 parallel to it.
5 are arranged.

One shaft 14 has an angular axis, and the other shaft 15 has a circular cross section.

A pair of left and right tractor holders 13 are slidably attached to the shafts 14 and 15.

In the tractor holder 13, a pin wheel 16 having a plurality of in 16a at equal angular intervals in the circumferential direction is provided,
It is rotated integrally with the shaft 14.

A pin wheel cover 17 is provided on the upper side of the tractor holder 13. Each of these pin wheel covers 17 can be opened and closed toward the outside on the left and right via a shaft 17a,
An opening 17b through which the pin 16 of the pin wheel 16 can pass is formed in the central portion.

The pin wheel cover 17 plays a role of pressing the fan hold paper 18 which is a recording paper fed by the pin wheel 16 from above and preventing it from floating.

On the other hand, a gear 19 is fixed to one end of the shaft 14, and the gear 19 meshes with a pinion gear 5b integral with the gear 5.

Therefore, the rotation of the stepping motor 6 is transmitted to the shaft 14 via the gear 19.

When the fan hold paper 18 is fed under the structure as described above, the pin wheel cover 17 is opened and the pins 16a are fitted into the small holes 18a formed on the both side edges of the fan hold paper 18, One end thereof is wound around the platen roller 1 and sandwiched between the platen roller 1 and the pinch roller 8, and the pin wheel cover 17 is closed to set.

When the apparatus is started in this state, as the recording is performed, the drive pulse for paper feeding is changed by the stepping motor 6
Is applied to the gears 7, 5,
The platen roller rotates in the clockwise direction in FIG. 2 via the belt 4 to feed the paper.

At the same time, the shaft 14 is rotated via the pinion gear 5b and the gear 19, and the pin wheel 16 is rotated counterclockwise in FIG.
The fan hold paper 18 is forcibly sent to the platen roller 1 side by the pin 16a.

That is, the paper is fed by the frictional force between the platen roller 1 and the pinch roller 8 by the amount forcibly fed by the pin wheel 16.

Therefore, the paper feed of fan hold paper is pinwheel
Although it is controlled by 16, the rotation is also performed by the platen roller 1. Therefore, if the rotations of the two are not completely synchronized, an error gradually accumulates, and the pin 16a and the small hole 18a of the fan hold paper do not mesh with each other. As a result, the small hole 18a may be torn and a paper jam may occur.

When the platen roller 1 thermally expands due to the influence of the ambient temperature and its diameter becomes large, the platen roller 1
In some cases, the small amount of paper feeding increases, the small hole 18a of the fan hold paper 18 and the pin 16a do not mesh with each other, and the small hole 18a is torn and a paper jam occurs.

[Objective] The present invention has been made in order to eliminate the above-mentioned conventional defects, and an object thereof is to provide a sheet conveying device capable of feeding fan-hold paper without causing paper jams or the like. There is.

[Examples] Hereinafter, details of the present invention will be described based on Examples shown in the drawings.

FIG. 3 illustrates one embodiment of the present invention.
The same parts as those in FIG. 2 and FIG. 2 are designated by the same reference numerals and the description thereof will be omitted.

In this embodiment, as shown in FIG.
At least one projection 8a is provided on the surface of the sword.

The tip of the protrusion 8a is formed in, for example, an arc shape, and is designed to reduce the frictional force when contacting the platen roller 1 via the fan hold paper 18 and the contact area.

Since the present embodiment is configured as described above, when the fan hold paper is set around the platen roller 1 from the pin wheel, and the stepping motor 6 is driven to feed the paper, the pinch roller 8 moves to 1 The protrusion 8a contacts the platen roller 1 at least once during rotation.

At this time, since the projection 8a and the fan hold paper 18 are almost in point contact with each other, the contact area is small and therefore the frictional force is also small, and as described above, the platen roller 1 and the pin wheel.
If a large tension is applied to the fan hold paper 18 due to a deviation in the synchronization of the 16 or the like, even if the fan hold paper 18 is fed by the tension, a slip occurs and the paper feed amount is reduced.

In addition, when the tension applied to the fan-hold paper is larger, the phenomenon that the fan-hold paper is pulled back by the tension also occurs.

As a result, the fan hold paper 18 is in an extremely natural state, and the small holes of the fan hold paper are not torn or paper jams do not occur.

It should be noted that the protrusion 8a may be provided in plural instead of one, and the tension of the fan-hold paper is adjusted more delicately as the number of protrusions increases.

Furthermore, by adopting such a structure, it is not necessary to adjust the synchronization between the platen roller 1 and the pin wheel 16 with high precision, and the degree of freedom in assembly is increased.
Assembly work becomes extremely easy.

[Effect] As is apparent from the above description, according to the sheet conveying apparatus of the present invention, a conveying unit that conveys the sheet by the pin while moving while engaging with the hole formed in the sheet side end portion,
And a pair of conveyance rotating bodies that sandwich and convey the sheet,
Since at least one protrusion is provided on one outer peripheral surface of the pair of transport rotating bodies so as to make point contact with a position where the sheet is wound on the outer peripheral surface of the other transport rotating body, it is possible to transport the sheet during transport. , When the conveyance rotating body provided with a protrusion on the outer peripheral surface makes one rotation and the protrusion makes a point contact with the sheet, the frictional force between the rotating conveyance body and the sheet decreases, and when a large tension is applied to the sheet, The sheet slips, the tension is reduced, and it is possible to prevent the sheet holes from being damaged or jammed. Moreover, since one of the conveying rotary members always presses the sheet against the other conveying rotary member by the outer peripheral surface or the protrusion, the sheet does not shift or float up, and when the sheet conveying device is used in the recording apparatus, It is possible to prevent the deviation of the recording position due to the deviation or the floating.

[Brief description of drawings]

1 and 2 are a perspective view and a side view of an essential part for explaining a conventional structure, and FIG. 3 is a side view of an essential part for explaining an embodiment of the present invention. 1 ... Platen roller 6 ... Stepping motor 8 ... Pinch roller 8a ... Protrusion, 13 ... Tractor holder 16 ... Pin wheel, 16a ... Pin 17 ... Pin wheel cover 18 ... Fan hold paper 18a ... Small hole

Claims (1)

[Claims] 1. A conveying means for conveying a sheet by a pin that moves while engaging with a hole formed at an end portion of the sheet, and a pair of conveying rotating bodies for nipping and conveying the sheet, the pair comprising: 2. A sheet conveying apparatus, wherein one outer peripheral surface of the conveying rotating body is provided with at least one protrusion that makes point contact with a position where the sheet is wound on the outer peripheral surface of the other conveying rotating body.