JPH11301903A - Tractor feeder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tractor feeder which can feed a continuous paper sheet smoothly. SOLUTION: In a tractor feeder 4A, a toothed part 15A of a belt 11A is projected from the inner peripheral surface 51 of the belt 11 at the middle part in the width direction, while a groove 10v, which guides the toothed part 15A of the belt 11, is formed around the outer peripheral surface 52 of a driven wheel 10A. In this case, the outer peripheral surface 52, is situated to the paper sheet 12 side from a guide surface 17h of a guide member 17A by the length of projection L of the toothed part 15A of the belt 11A, so that the inner peripheral surface 51 of the belt 11A abuts on the outer peripheral surface 52 of the driven wheel 10A.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tractor feeder used for a printer, which feeds a sheet while catching a pin in a hole of the sheet. More specifically, the present invention relates to a tractor feeder that enables a sheet to be smoothly fed.

[0002]

2. Description of the Related Art As is well known, a printer of this type comprises a printing means for printing on paper, a mechanism for feeding paper, and other parts such as a control circuit and a power supply. Some of such printers use a tractor feeder to feed paper.

FIG. 7 is a perspective view of an example of a printer viewed from the rear side. The printer 1 shown in FIG. 1 includes a print head 2 that prints on paper, a platen 3 that feeds and prints the paper, and a tractor feeder 4 that feeds the paper.
And other parts such as a control circuit and a power supply. This tractor feeder 4 has two parallel axes 5, 6
, And receives rotational driving force from one of the shafts 5.

FIG. 8 is an enlarged sectional view showing the conventional tractor feeder, FIG. 9 is an enlarged sectional view showing a main part of the tractor feeder, and FIG. 10 is a sectional view showing the tractor feeder. It is sectional drawing of the belt used. 8 to 10, the tractor feeder 4 includes:
The configuration is roughly as follows. That is, a driving wheel 8 is rotatably provided on a base (not shown) having a predetermined shape, and the driving wheel 8 receives a driving force from the shaft 5. On the outer periphery of the drive wheel 8, teeth 9 having a predetermined pitch are provided. In addition, in the base,
A driven wheel 10 is rotatably provided. This drive wheel 8
A belt 11 is stretched around the driven wheel 10.
As shown in FIGS. 8 to 10, on the outer peripheral surface of the belt 11, a pin 14 which catches on the feed hole 13 of the continuous paper 12, and on the inner peripheral surface of the belt 11, The teeth 15 having a meshing pitch are provided over the entire width in the lateral direction (width direction) of the belt.

[0005] Further, the cover 1
6 are provided, and the cover 1
2 is pressed toward the belt 11. A guide member 17 is provided between the drive wheel 8 and the driven wheel 10 of the base. The guide member 17 has a guide surface 1 with which the teeth 15 on the inner peripheral surface of the belt 11 contact.
The guide surface 17h prevents the belt 11 from dropping. Further, by fixing the latching body 18 to the base provided with the driving wheel 8, the driven wheel 10, and the belt 11, these members can be hooked to the base.

In the printer 1 having the tractor feeder 4 having such a structure, the continuous paper 12 is hooked on the pin 14 of the tractor feeder 4 of the printer 1 through the hole 13 of the paper and passes through the platen 3 of the printer 1. Then, it is printed by the print head 2 or sent out of the printer 1 without being printed.

[0007]

By the way, in the case of the tractor feeder 4 described above, as shown in FIG. 9, due to the perforation 12a of the continuous paper 12, the arrow F
As shown in (1), there is a problem in that the belt 11 is pressed down, the teeth 15 of the belt 11 hit the projection 17p of the guide member 17 and are caught, and the belt 11 is locked, so that the paper cannot be fed.

In order to solve this problem, the guide member 17 may be eliminated, or the tooth portion 15 of the belt 11 may be removed.
When the distance between the belt 11 and the flat surface 17h of the guide member 17 is increased, the belt 11 is pushed, the pins 14 of the belt 11 come off from the feed holes 13 of the continuous paper 12, and the continuous paper 12 cannot be fed. was there.

An object of the present invention is to provide a tractor feeder which can solve the above-mentioned problems of the prior art and can feed a sheet smoothly.

[0010]

According to a first aspect of the present invention, there is provided a tractor feeder having a predetermined shape and a predetermined pitch rotatably provided on the base. A driving wheel having a tooth portion, a driven wheel rotatably provided on the base, a pin that is hung over the driving wheel and the driven wheel, and that is caught in a hole in a sheet is provided on an outer peripheral surface of a tooth of the precursor driving wheel. A belt provided on the inner peripheral surface with a tooth portion meshing with the portion, a cover body for pressing a sheet toward the belt side, and a tooth tip of the belt provided between the drive wheel and the driven wheel of the base. A guide member having a guide surface for guiding the belt by contacting the surface.
In the feeder, the tooth portion of the belt is provided on an inner peripheral surface of the belt and protruded at a part in the width direction, and a groove for guiding the tooth portion of the belt is provided on an outer peripheral surface of the driven wheel. The outer peripheral surface of the driven wheel is positioned on the paper side at least by the protruding length of the tooth portion of the belt from the guide surface of the guide member, and the inner peripheral surface of the belt contacts the outer peripheral surface of the driven wheel. It is characterized in that it touches.

According to the present invention, the inner peripheral surface of the belt comes into contact with the outer peripheral surface of the driven wheel, and the teeth of the belt are guided in the grooves of the driven wheel, and at the same time, the tips of the teeth of the belt are connected to the guide members. Since the belt slides in contact with the guide surface, even if the belt is pressed down from the cover body side, the belt is securely held without bending. Therefore, the problem that the belt lock is generated by entering the gap between the driven wheel and the guide member is eliminated,
Paper can be sent smoothly.

In addition, the manner in which the driven wheel and the belt contact each other is such that the tooth portion of the belt inner peripheral surface, which is not flat but has an uneven structure, is in contact with the outer peripheral surface of the uniformly flat driven wheel. On the other hand, in the present invention, the flat surfaces of the inner peripheral surface of the belt, which is a uniform flat surface, and the outer peripheral surface of the driven wheel having the same uniform flat surface are in contact with each other, avoiding the position of the tooth portion. In addition, the vibration caused by the conventional uneven structure does not occur at all, the device can be driven in a stable state, and the risk of occurrence of belt lock can be reduced from this point as well.

According to a second aspect of the present invention, in the first aspect of the present invention, the tooth portion of the belt is provided so as to protrude from a central portion in the width direction of the belt, and is moved away from the belt. It is characterized by being formed in a substantially trapezoidal shape that becomes narrow. Accordingly, the belt and the driven wheel come into contact with each other in a balanced state with good structural symmetry, so that the occurrence of belt lock can be prevented in a state where the stability is extremely high.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 6 are views for explaining a tractor feeder according to one embodiment of the present invention. Here, FIG. 1 shows a tractor feeder according to the first embodiment, and is an enlarged cross-sectional view along the line AA in FIG. 4, and FIG. 2 shows one of belts used in the tractor feeder. FIG. 3 is a sectional view of a driven wheel used in the tractor feeder, and FIG.
FIG. 5 is a perspective view showing a feeder, FIG. 5 is a perspective view showing a state in which a hook and a cover are removed from a base body in the first embodiment, and FIG. 6 is an exploded perspective view of the first embodiment. .

The difference between the tractor feeder 4A according to the embodiment shown in these figures and the conventional tractor feeder 4 is that the teeth 15A of the belt 11A
A groove 10v that guides the teeth 15A of the belt 11A is formed on the inner peripheral surface 51 of the belt 1A and protrudes from the inner peripheral surface 51 of the belt 11A at a part in the width direction, that is, at the center in this embodiment. And the outer peripheral surface 52 of the driven wheel 10A is at least as large as the belt 1 than the guide surface 17h of the guide member 17A.
The point is that the inner peripheral surface 51 of the belt 11A comes into contact with the outer peripheral surface 52 of the driven wheel 10A by the protrusion length L of the tooth portion 15A of 1A. Therefore, the same components as those of the conventional tractor feeder 4 are denoted by the same reference numerals and described.

The tractor feeder 4A according to the embodiment of the present invention is configured as follows. That is, as shown in FIG. 6, the base 7A is made of a material such as plastic, and the plate 20 is attached to one end of the plate 20.
And a paper sliding surface 21 formed at a right angle to form a predetermined shape. A drive bearing 22 is provided on the plate body 20, and a hollow cylindrical driven shaft 23 is integrally formed at a position on the plate body 20 at a predetermined distance from the bearing 22. Further, a guide member 17A is provided by integral molding between the drive bearing 22 and the driven shaft 23 of the base 7A. The screw hole 2 is provided in the guide member 17A.
4 are provided, and positioning holes 25 and 26 are provided above and below the screw hole 24 in the figure.

The guide member 17A is configured such that a guide surface 17h formed on the upper and lower sides in the drawing is extended toward the driven wheel 10A, and a side surface 17j of the guide member 17A is formed in a shape substantially along the outer peripheral surface of the driven wheel 10A. .

The driving wheel 8 comprises a rotating body 31 provided with the teeth 9 and drive shafts 32 provided on both sides of the rotating body 31. This drive shaft 32,
At 32, a square hole Hr is formed. One of the drive shafts 32 is rotatably fitted to the drive bearing 22 of the base 7A. The driven wheel 10A is formed in an annular shape, and the driven wheel 10A is rotatably fitted to a driven shaft 23 of the base 7A.

As shown in FIG. 3, a groove 1 having a V-shaped cross section in the center of an outer peripheral surface 52 thereof is formed in the driven wheel 10A.
0v is formed over the entire circumference, and the teeth 15A of the belt 11A are fitted into the grooves 10v.
For this reason, as shown in FIG. 2, the tooth portion 15A of the belt 11A is formed in a trapezoidal shape at the center of the inner peripheral surface 51 of the belt 11A in a vertical cross section.

Then, as shown in FIG. 1, the driven wheel 10A
The outer peripheral surface 52 of the paper 1 has a length L that the tooth portion 15A of the belt 11A protrudes from the guide surface 17h of the guide member 17A.
It is formed so as to be located on two sides. In this embodiment, between the width S of the guide member 17A, the outer diameter D of the driven wheel 10A, and the protruding length L of the tooth portion 15 of the belt 11A,
As shown in FIG. 1, the guide member 17A and the driven wheel 10A are formed in a symmetrical structure so that the relationship of D ≧ S + L is established. The driven wheel 10A thus formed
And a driving wheel 8, a belt 11A is stretched over, and a driven wheel 10A
The tooth 15A of the belt 11A is inserted into the groove 10v, and the inner peripheral surface 51 of the belt 11A is driven by being brought into contact with the outer peripheral surface 52 of the driven wheel 10A.

The hook body 18 is formed of a material such as plastic on a plate 50 having a predetermined shape.
0 is provided with a projection (not shown) that fits into the positioning holes 25 and 26 of the base 7A, and the plate body 50 has a driven bearing into which the driven shaft 23 is inserted. 33,
The engagement hole 35 into which the engagement screw 34 is inserted, the drive wheel 8
A drive bearing 38 into which the drive shaft 32 is inserted is bored. On the other surface of the plate body 50 of the hook body 18, an engagement bearing 37 with which the engagement shaft 36 of the cover body 16 is engaged is provided. The engaging projections for positioning the hook body 18 are fitted into the positioning holes 25 and 26 of the guide member 17A of the base 7A, and the driven shaft 23 is
The drive shaft 32 of the drive wheel 8 is fitted into each of the
Into the screw hole 2 of the guide member 17A.
4, the hook 18 is fixed to the base 7 </ b> A.

The engagement shaft 37 of the cover 16 is engaged with the engagement bearing 37 of the hook 18 so that the cover 1
6 can be tilted to the paper sliding surface 21 side or raised.

In the tractor feeder 4A of such an embodiment, the tooth portion 15A of the belt 11A is formed in a trapezoidal shape at the center of the inner peripheral surface 51 of the belt 11A, and the outer peripheral surface of the driven wheel 10A. 52, a V-shaped groove 10v is formed, and the relationship of D ≧ S + L is established between the width S of the guide member 17A, the outer diameter D of the driven wheel 10A, and the protruding length L of the teeth 15 of the belt 11A. Is established, the teeth 15A of the belt 11A are guided without any obstacle on the guide surface 17h of the guide member 17A, and the paper can be fed smoothly without the occurrence of the belt lock.

[0024]

According to the present invention, the inner peripheral surface of the belt comes into contact with the outer peripheral surface of the driven wheel, and the tooth portion of the belt is guided in the groove of the driven wheel, and at the same time, the distal end surface of the tooth portion of the belt is guided. Since the belt slides in contact with the guide surface of the member, the belt is securely held without bending even when pressed from the cover body side. Therefore, there is no problem that the belt enters the gap between the driven wheel and the guide member and the belt is locked, and the paper can be fed smoothly.

Further, the manner in which the driven wheel and the belt are in contact with each other depends on the outer peripheral surface of the driven wheel having the same uniform flat surface as the inner peripheral surface of the belt, which is a uniform flat surface avoiding the positions of the teeth. Because the flat surfaces are not vibrated, vibration can be prevented and the device can be driven in a stable state. In this respect, the risk of occurrence of belt lock can be reduced.

[Brief description of the drawings]

FIG. 1 is an enlarged sectional view showing a tractor feeder according to an embodiment of the present invention, taken along line AA of FIG.

FIG. 2 is an enlarged sectional view showing a belt used in the embodiment.

FIG. 3 is an enlarged sectional view showing a driven wheel used in the embodiment.

FIG. 4 is a perspective view showing a tractor feeder according to the embodiment of the present invention.

FIG. 5 is a perspective view showing a state in which the hook and the cover are removed from the base in the embodiment.

FIG. 6 is an exploded perspective view in the same embodiment.

FIG. 7 is a perspective view illustrating an example of a printer.

FIG. 8 is an enlarged sectional view showing a configuration example of a conventional tractor feeder.

FIG. 9 is a diagram for explaining a drawback of a conventional tractor feeder.

FIG. 10 is an enlarged sectional view showing a belt used in a conventional tractor feeder.

[Explanation of symbols]

 Reference Signs List 4A Tractor feeder 7A Base 8 Drive wheel 9 Teeth 10A Follower wheel 10v Groove 11A Belt 12 Continuous paper 13 Hole 14 Pin 15A Teeth 16 Cover body 17A Guide member 17h Guide surface 51 Inner peripheral surface of belt 52 Outer peripheral surface of driven wheel D Outer diameter of driven wheel S Width of guide member L Projection length of tooth of belt

Claims (2)

[Claims] 1. A base having a predetermined shape, a drive wheel rotatably provided on the base and having teeth at a predetermined pitch, a driven wheel rotatably provided on the base, and the drive wheel. A belt provided on an outer peripheral surface of a pin that is hooked on the driven wheel and hooked on a hole of a sheet, a belt provided on an inner peripheral surface with a tooth portion that meshes with a tooth portion of a precursor driving wheel, and a cover body that presses the sheet toward the belt side And a guide member provided between the drive wheel and the driven wheel of the base and having a guide surface that guides the belt by contacting a tooth tip surface of the belt. The tooth portion of the belt is provided on the inner peripheral surface of the belt and protrudes at a part in the width direction. A groove for guiding the tooth portion of the belt is provided on the outer peripheral surface of the driven wheel. The outer peripheral surface is less than the guide surface of the guide member. Tractor feeder, characterized in that the only projecting length of the teeth of the belt become positioned on the paper side, the inner peripheral surface of the belt on the outer circumferential surface of the driven wheel is such that contact. 2. The belt according to claim 1, wherein the tooth portion of the belt is formed in a substantially trapezoidal shape so as to protrude from a central portion in a width direction of the belt and to become narrower as the distance from the belt increases. Tractor feeder.