JPH04115660U - Driving force transmission device in line printer - Google Patents

Abstract

(57) [Summary] [Purpose] To improve the positional accuracy between bevel gears used in the driving force transmission device of a line printer, eliminate backlash, and improve paper feeding pitch accuracy. [Configuration] The first gearbox 14 is fitted onto the platen shaft 13 so as to be movable in the axial direction, and the rotation of the gearbox 14 is controlled by a pin.
15 prevents. A second gearbox 16 and a motor 17 are integrally attached to the first gearbox 14. A first bevel gear 22 is attached to the first gear box 14 by a gear shaft 21. A second bevel gear 23, which is integral with the platen shaft 13, is meshed with the first bevel gear 22. Said platen shaft 13
A spring 24 is provided at the holder, and the stopper 25 locks the holder. The spring 24 elastically pushes the first gearbox 14 to force the first bevel gear 22 against the second bevel gear 23. This eliminates backlash between the bevel gears 22 and 23.

Description

[Detailed explanation of the idea]

0001 [Purpose of invention]

0002

[Industrial application field]

The present invention relates to a driving force transmission device for a line printer.

0003

[Conventional technology]

As shown in FIG. 2, the conventional small line printer has a side surface of the printer body 1. A stepping motor 2 is attached to the A shaft 3 is arranged.

0004 This type of stepping motor 2 is a thin motor whose radial dimension is larger than its axial dimension. However, when using such a motor, the height of the entire printer must be the same as that of motor 2. Depends on outer diameter.

[0005] In other words, due to the height of the printer body 1, the size of the stepping motor 2 (larger diameter) ) is limited.

[0006] Therefore, as shown in FIG. 3, the motor shaft 3 is connected to the platen shaft 4a of the platen 4. The motor 2 is arranged vertically, and a bevel is placed in the drive force transmission path. By providing gears 5 and 6, the printer can be easily installed without increasing the overall height of the printer. It is now possible to increase the size of the stepping motor 2 (increase in diameter).

[0007] In the conventional driving force transmission device using these bevel gears 5 and 6, one bevel gear 5 is fixed concentrically with the platen shaft 4a, and the other bevel gear 5 meshes with the one bevel gear 5. A bell gear 6 is attached to the gearbox 8 by a vertical gear shaft 7, and this gear The abox 8 is attached to the printer main body 1 by a mounting plate 9. stop By increasing the positional accuracy between the printer body 1 and the gearbox 8, the platen 4 We are trying to improve the rotation accuracy of the

[0008]

[Problem that the idea aims to solve]

The driving force transmission device shown in FIG. , between the printer body 1 and the gearbox 8, and between the gearbox 8 and the gear shaft 7. Due to the accumulation of positional accuracy errors, one bevel gear 5 and the other bevel gear 5 The positional accuracy error between the gear 6 and the gear 6 is determined. Therefore, the position accuracy between bevel gears Errors become large, and achieving high precision requires time and effort in processing, assembly, etc. There is a drawback of cost.

[0009] Furthermore, once the bevel gears 5 and 6 of the driving force transmission device shown in FIG. If this occurs, the degree of freedom in the platen axis direction will be lost, so do not clean between bevel gears 5 and 6. It is essential to provide balance (backlash). For this reason, the bevel Due to the backlash between gears 5 and 6, the rotation accuracy of the platen 4 deteriorates, and as a result, There is a problem that the paper feed pitch accuracy decreases.

0010 The present invention was developed in consideration of these points, and it is based on the mounting position standard of gearbox. is placed on the platen axis, and the degree of freedom of the gearbox in the platen axis direction is set as a spring. By ensuring that The purpose of this is to eliminate paper feed pitches and improve paper feed pitch accuracy.

[0011] [Structure of the idea]

0012

[Means to solve the problem]

The present invention is based on a line prism that transmits the rotation of the motor 17 to the platen shaft 13 via gears. In the printer, the drive unit including the motor 17 is integrally attached and is attached to the platen shaft 13. A gearbox 14 is fitted so as to be movable in direction and locked in rotation, and this gearbox a first bevel gear 22 attached to the gearbox 14 and rotated by the drive section; A second bevel gear meshed with the first bevel gear 22 and integrally attached to the platen shaft 13; gear 23, which is provided on the platen shaft 13 and elastically presses the gear box 14. and a spring 24 that presses the first bevel gear 22 against the second bevel gear 23. This is a driving force transmission device equipped with

[0013]

[Effect]

In this invention, two bevel gears are connected via a gearbox 14 provided on a platen shaft 13. In addition to directly positioning gears 22 and 23, the gearbox 14 is elastically moved by the spring 24. By pressing the first bevel gear 22 on the gearbox side and the platen shaft side To eliminate backlash between the second bevel gear 23 and the second bevel gear 23.

[0014]

【Example】

Hereinafter, the present invention will be explained in detail with reference to the embodiment shown in FIG.

[0015] A platen shaft 13 integrated with a platen 12 in the printer body 11 of a thermal line printer is rotatably mounted.

[0016] A first gear box 14 is fitted to this platen shaft 13 so as to be movable in the axial direction. . A pin 15 is provided protruding from this first gearbox 14, and this pin 15 is connected to the printer body. 11 so as to be movable in the axial direction, and lock the first gearbox 14 so that it does not rotate. are doing.

[0017] A stepping motor is connected to this first gearbox 14 via a second gearbox 16. Data 17 is installed integrally. This second gearbox 16 and motor 17 Drive unit. The second gearbox 16 contains a gear train. stepping motor The motor 17 has a thickness in the axial direction (vertical direction) of the motor shaft 18 that is larger than the outer diameter (horizontal dimension). It is a thin motor with a small size.

[0018] From the second gearbox 16 as the drive unit to the first gearbox 14 A protruding gear shaft 21 is rotatably fitted, and the first bevel gear is connected via this gear shaft 21. A22 is installed.

[0019] A second bevel gear 23 that meshes with the first bevel gear 22 is attached to the platen shaft 13. It is installed in one piece.

[0020] A spring 24 is fitted to the tip of the platen shaft 13. this spring 24 is locked by a stopper 25 fitted integrally with the platen shaft 13, and this stopper compressed between the gearbox 25 and the first gearbox 14, and the first gearbox 14 is compressed. The first bevel gear 22 is pressed against the second bevel gear 23 by force.

[0021] Next, the operation of the embodiment shown in FIG. 1 will be explained.

[0022] The rotational force output from the stepping motor 17 is applied to the teeth in the second gearbox 16. Vehicle train, gear shaft 21, first bevel gear 22, second bevel gear 23 and then platen shaft 13 is transmitted to rotate the platen 12, and a wire (not shown) wrapped around this platen 12 Feeds paper by a specified amount.

[0023] In this case, is the first gear box 14 installed with the platen shaft 13 as a reference? The first bevel gear 22 attached to this first gearbox 14 and the platen The positional relationship with the second bevel gear 23 provided on the shaft 13 can be maintained with high precision. Sara Since the spring 24 always presses the first gearbox 14 toward the platen, , the first bevel gear 22 attached to the first gear box 14 and the platen shaft 13. Backlash does not occur between the attached second bevel gear 23 and the attached second bevel gear 23. For this reason, High paper feeding accuracy can be obtained.

[0024]

[Effect of the idea]

According to this invention, even when a bevel gear is used due to the adoption of a thin and large diameter motor, , a gearbox installed on the platen shaft, or a gearbox that is elastically pressed. The first bevel gear is pressed against the second bevel gear by a spring or the like. Since the positional accuracy between the bell gears can be increased, the rotational accuracy of the platen can be improved. As a result, paper feeding accuracy can be improved.

[Brief explanation of drawings]

FIG. 1 is a front view showing an embodiment of a driving force transmission device in a line printer of the present invention.

FIG. 2 is a perspective view showing a motor mounting portion in a conventional line printer.

FIG. 3 is a perspective view showing a driving force transmission device in another conventional line printer.

[Explanation of symbols]

13 Platen axis 14 Gearbox 17 motor 22 1st bevel gear 23 Second bevel gear 24 spring

──────────────────────────────────────────────── ─── Continuation of front page (72) Creator Akio Mizumura 1-19-43 Higashioizumi, Nerima-ku, Tokyo Stocks Inside Tamura Manufacturing Company

Claims (1)

[Scope of utility model registration request] 1. A line printer that transmits the rotation of a motor to a platen shaft via gears, in which a driving section including the motor is integrally attached, is fitted to the platen shaft so as to be movable in the axial direction, and is engaged in rotation. a stopped gearbox,
a first bevel gear attached to the gear box and rotated by the drive unit; a second bevel gear meshed with the first bevel gear and attached integrally to the platen shaft; and a second bevel gear provided on the platen shaft. A driving force transmission device for a line printer, comprising: a spring that elastically presses the gear box and presses the first bevel gear against the second bevel gear.