JPH07237324A - Paper feed driver in thermal printer - Google Patents

Abstract

PURPOSE:To suppress a temperature increase of a motor without deteriorating a positional accuracy of a gear of a paper feed driver in a thermal printer to enhance a safety and a life. CONSTITUTION:A mounting flange 11 of a motor 1 is brought into close contact with an outer surface of an aluminum box member 2. A gear mounting member 3 is fitted into an inner surface of the aluminum box member 2. The motor 1, the aluminum box member 2, and the gear mounting member 3 are positioned and fixed by a screw 67. A T-shaped engaging part 26 provided in the aluminum box member 2 is engaged with a positioning recess 42 of a main frame 4. Lastly, a screw insertion hole 38 of the gear mounting member 3 is positioned to a screwed hole of the main frame 4 and fixed by a screw 68. The aluminum box member 2 efficiently releases a heat generated from the motor 1. The gear mounting member 3 positions gears 13, 33, 34, 51 with high accuracy.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper feed drive device for a thermal printer.

[0002]

2. Description of the Related Art As disclosed in Japanese Patent Laid-Open No. 3-182369, a conventional paper feeding drive device for a thermal printer mounts a motor on a gear mounting member, and the gear mounting member is screwed to a main frame of the thermal printer. do it,
The drive force transmission mechanism by the gear train in the gear attachment member is attached to the main frame.

[0003]

In this conventional paper feed drive device, the motor is directly attached to the gear attachment member.
The gear mounting member has little effect of radiating heat generated by the motor. For example, the heat radiating effect is significantly inferior to that of an aluminum member, the motor temperature becomes very high, and the safety and life performance of the device are deteriorated. There is.

On the other hand, when the gear mounting member is formed of an aluminum member, it lacks reliability as a gear mounting member that pivotally supports the gear in a fixed position in terms of rigidity and wear resistance, and printing due to deterioration of gear position accuracy. There is a problem that leads to quality deterioration.

The present invention has been made in view of the above points, and it is possible to suppress the temperature rise of the motor without impairing the positional accuracy of the gears and to improve the safety and the life performance of the thermal printer. It is an object to provide a driving device.

[0006]

According to a first aspect of the present invention, there is provided a motor as a paper feed driving source, a driving force transmitting mechanism portion for decelerating and transmitting the rotation of the motor, and the driving force transmitting mechanism portion. In a paper feed driving device of a thermal printer, which comprises a main frame rotatably supporting a platen roller driven via a roller, the driving force transmission mechanism is divided into a heat radiating member and a gear mounting member. This is a paper feed drive device for a thermal printer, which is characterized by the points. The heat dissipation member is formed of a plate-shaped material having excellent heat dissipation, and is closely attached to a mounting flange integrally provided on the motor. The gear mounting member is positioned between and fixed to the heat radiating member and the main frame, and rotatably supports an intermediate gear that meshes with the drive gear of the motor and the driven gear of the platen roller.

According to a second aspect of the present invention, in the paper feed drive device for a thermal printer according to the first aspect, a gear mounting member is provided inside a box-shaped aluminum box member formed of an aluminum plate as a heat dissipation member. , The motors are respectively positioned on the outside and fixed by screws, and the one side portion of the main frame and the corresponding one side portion of the aluminum box-shaped member are positioned and engaged, and the other side portion of the main frame is positioned. And a corresponding other side portion of the gear mounting member is fixed by a screw.

[0008]

According to the first aspect of the present invention, the gears for transmitting the driving force are accurately positioned and meshed with each other on the basis of the gear mounting member. The heat radiation member in close contact with the mounting flange of the motor efficiently radiates the heat generated from the motor and reduces the temperature rise of the motor.

According to the second aspect of the present invention, the gear mounting member is positioned inside and fixed to the outside of the aluminum box-shaped member, and the motor is positioned outside the aluminum box-shaped member, and one side portion of the main frame corresponds to the aluminum box-shaped member. One of the side portions of the main frame and the corresponding other side portion of the gear mounting member are fixed by screws.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the embodiments shown in the drawings.

FIG. 1 shows a paper feed driving device for a thermal printer according to the present invention, which comprises a motor 1 as a paper feed driving source,
It is composed of a driving force transmission mechanism portion 10 that decelerates and transmits the rotation of the motor 1, and a main frame 4 that rotatably supports a platen roller 5 driven through the driving force transmission mechanism portion 10. To be done.

The motor 1 is integrally provided with a mounting flange 11 on the drive shaft protruding side of the motor body.

The driving force transmission mechanism portion 10 includes an aluminum box-shaped member 2 formed in a box shape with an aluminum plate as a heat dissipation member, and a gear mounting member 3 fixed inside the aluminum box-shaped member 2. Consists of.

The aluminum box-shaped member 2 is formed by bending an aluminum flat plate to form four surfaces including a motor mounting surface portion 21, left and right side surface portions 22 and 23, and an upper surface portion 24, or five surfaces including a bottom surface portion (not shown). It is a heat dissipation member formed in a box shape.

One side surface portion 23 of this aluminum box-shaped member 2
Then, the T-shaped engaging portion 26 for positioning is formed by cutting the convex groove 25 from above and below. This T-shaped engaging portion 26
Is a fitting part 27 that fits with one side edge of the main frame 4.
And a contact portion 28 that engages with the inner surface portion of the main frame 4.

The gear mounting member 3 is formed by bending a gear mounting surface portion 31 and a bottom plate portion 32 into a substantially L shape by using a metal plate having rigidity and wear resistance, and the gear mounting surface portion 31 has two large and small intermediate gears. 33 and 34 are rotatably supported by a common shaft 35. The large intermediate gear 33 meshes with the drive gear 13 attached to the drive shaft 12 of the motor 1, and the small intermediate gear 34 is
It meshes with a driven gear 51 attached to the shaft end of the platen roller 5.

Further, the gear mounting member 3 is provided with a notch 36 for inserting a screw in the lower portion of the gear mounting surface 31, and a screw stop 37 is projected from the bottom plate 32 on the side facing the notch 36. The screw stop 37 is provided with a positioning hole C and a screw insertion hole 38.

A bearing groove 41 for rotatably supporting the platen roller 5 and a positioning groove 42 at a position corresponding to the T-shaped engaging portion 26 of the aluminum box-shaped member 2 are provided on one side plate portion of the main frame 4. A protrusion D at a position corresponding to the positioning hole C of the gear mounting member 3, a screw thread insertion hole 43 at a position corresponding to the screw insertion hole 38, and a stopper 44 for locking a spring unit described later are provided. ing.

A boss A is provided at a corresponding position of the mounting flange 11 of the motor 1 and the motor mounting surface portion 21 of the aluminum box-shaped member 2.
And a hole B for inserting the drive gear 13 of the motor 1 at a corresponding position of the gear mounting surface portion 31 of the gear mounting member 3. 65 and two screw threaded holes 63 are provided.

Motor mounting surface portion 21 of the aluminum box-shaped member 2
And the gear mounting surface portion 31 of the gear mounting member 3 has a gear 33,
Holes 66 are formed to fit the bearings of 34.

Next, the procedure for assembling this paper feeding drive device will be described. The mounting flange 11 of the motor 1 is brought into close contact with the outer surface of the aluminum box-shaped member 2 and the gear mounting member is mounted on the inner surface of the aluminum box-shaped member 2. Insert 3 and make contact. At this time, in the positioning hole E and the elliptical hole F formed in the motor mounting surface portion 21 of the aluminum box-shaped member 2, two projecting portions G and H projecting at corresponding positions of the gear mounting member 3 are provided. Fit and position.

The positioning protrusions D, G, H are dowels formed in a cylindrical shape on the sheet metal by pressing.

Then, the two screws 67 are screwed from the screw insertion holes 61 of the motor 1 through the screw insertion holes 62 of the aluminum box-shaped member 2 into the screw screw insertion holes 63 of the gear mounting member 3 to make the motor 1 , The aluminum box-shaped member 2 and the gear mounting member 3 are positioned and fixed and integrated.

After that, the T-shaped engaging portion 26 of the aluminum box-shaped member 2 is fitted into the positioning groove 42 of the main frame 4, and the contact portion of the T-shaped engaging portion 26 is attached to the inner surface of the main frame 4. 28, the projection D of the main frame 4 is fitted into the positioning hole C of the gear mounting member 3, and finally the screw insertion hole 43 of the main frame 4 is fitted into the screw insertion hole of the gear mounting member 3.
The screw fastening part of the gear mounting member 3 by the screw 68 screwed from 38
Fix 37 to the main frame 4.

As a result of such assembly, as shown in FIG. 2, the gears 13, 33, 34, 51 for transmitting the motor driving force are accurately positioned with respect to the gear mounting member 3 and mesh with each other. The aluminum box-shaped member 2 for heat radiation can be easily assembled, and the heat generated from the motor 1 is radiated more efficiently than the aluminum box-shaped member 2 that is in close contact with the mounting flange 11 to reduce the temperature rise of the motor 1. be able to.

The side surface portions 22 and 23 and the upper surface portion 24 of the aluminum box-shaped member 2 function as a safety cover for the gears 13, 33, 34 and 51 and also have a function of expanding the heat radiation area.

FIG. 2 shows the whole of the thermal printer in which the assembly of the paper feeding drive device is completed, and for the platen roller 5 axially supported between the both side plate portions of the main frame 4,
A thermal head 72 is swingably provided around a fulcrum shaft portion 71, and the back surface of the thermal head 72 and the main frame 4 are provided.
A spring unit 73 is fitted between the stopper 44 of the thermal head and the spring unit 73.
72 is pressed against the platen roller 5 side.

The spring unit 73 has a pair of coil springs 77 installed between a pressing plate 75 and an engaging plate 76 connected by a hinge shaft 74 at the rear part. When the coil springs 77 are compressed by sandwiching them with each other, they are inserted between the back surface of the thermal head 72 and the stopper 44 of the main frame 4 and engaged with each other.
The pressing plate 75 that is acted downward by the restoring force of the compression coil spring 77 against the engaging plate 76 locked by the stopper 44.
However, the back surface of the thermal head 72 is elastically pressed toward the platen roller 5 side.

The thermal head 72 has a pushed-up portion on one side.
A cam 82 which integrally has 81 and which engages with the pushed-up portion 81 on its peripheral surface is rotatably supported by the outer surface of the main frame 4. Then, when setting or resetting the printing paper, the cam 82 is rotated by the lever 83 to separate the thermal head 72 from the platen roller 5 from one side thereof.

[0030]

According to the first aspect of the invention, since the gear mounting member improves the positional accuracy of the gear, high print quality is obtained, and the heat dissipation member reduces the temperature rise of the motor. The safety and life performance of the device can be improved.

According to the second aspect of the present invention, one side portion of the integrated aluminum box-shaped member and the other side portion of the gear mounting member are positionally engaged with corresponding portions of the main frame and fixed with screws. By doing so, the aluminum box-shaped member as the heat dissipation member can be effectively used as the attachment member, and the paper feed drive device can be easily assembled.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing an embodiment of a paper feeding drive device according to the thermal printer of the present invention.

FIG. 2 is a perspective view of the same thermal printer as above.

[Explanation of symbols]

 1 motor 2 aluminum box type member as heat dissipation member 3 gear mounting member 4 main frame 5 platen roller 10 driving force transmission mechanism 11 mounting flange 13 driving gear 33, 34 intermediate gear 51 driven gear 67, 68 screw

Claims (2)

[Claims] 1. A motor that serves as a paper feed drive source, a drive force transmission mechanism unit that decelerates and transmits the rotation of the motor, and a platen roller that is driven via the drive force transmission mechanism unit so as to rotate freely. In a paper feed drive device of a thermal printer including a supporting main frame, the drive force transmission mechanism portion is formed of a plate-shaped material having excellent heat dissipation, and a mounting flange integrally provided on the motor. A heat-dissipating member that is closely attached and an intermediate gear that is positioned and fixed between the heat-dissipating member and the main frame and that meshes with the drive gear of the motor and the driven gear of the platen roller are rotatably supported. And a gear mounting member, which is divided into two parts. 2. A gear mounting member is positioned inside an aluminum box-shaped member formed in a box shape by an aluminum plate as a heat radiating member, and a motor is positioned outside and fixed by screws. The side part and one corresponding side part of the aluminum box-shaped member are positioned and engaged, and the other side part of the main frame and the corresponding other side part of the gear mounting member are fixed by screws. The paper feed driving device of the thermal printer according to claim 1.