JPS6347487Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a driving force transmission mechanism in a printing device such as a printer, typewriter, facsimile, or the like.

Conventionally, the platen drive mechanism of a printer has been configured as shown in FIG. 1, for example. What is indicated by the reference numeral 10 in the figure is a frame. In frame 10,
Motor 16 is mounted using two mounting screws 12,14. A motor shaft 18 of the motor passes through the frame 10 and has a motor gear 20 at the tip. The motor gear 20 meshes with an intermediate wheel 22. The intermediate wheel is supported by an intermediate axle 24 erected on the frame 10, and is rotatable about the intermediate axle. The intermediate wheel 22 meshes with the platen gear 26. The platen gear is mounted on a platen shaft 28 that is attached to the frame 10. The platen shaft has a platen 30, and platen knobs 32 are attached to both ends. Then, the rotation of the motor 16 causes the motor gear 20 to rotate.
is transmitted to the intermediate wheel 22 using the intermediate wheel, and is transmitted to the platen gear 26 via the intermediate wheel, so that the platen
0 is set to be rotated.

By the way, in this type of platen drive mechanism, in order to improve printing alignment, the motor gear 20
and intermediate wheel 22 and intermediate wheel 22 and platen gear 2
6 and 6 were kept as small as possible.

Therefore, if the intermediate wheel 22, which is usually made of resin, thermally expands due to changes in the usage environment, the motor 1
There was a drawback that the load torque applied to 6 suddenly increased.

Therefore, the purpose of this invention is to obtain a driving force transmission mechanism for the above-mentioned type of printing device that does not have such drawbacks, and the motor is connected to a frame or the like through an elastic member made of rubber, resin, etc. It is supported by a fixed member.

Hereinafter, the driving force transmission mechanism according to this invention will be explained based on the embodiment shown in the drawings. For the same parts in the drawings as in FIG. 1, the same reference numerals as in FIG. 1 are used.

First, in FIGS. 2 and 3 showing an embodiment of this invention, a motor 16 such as a pulse motor
connects the flange 34 with rubber spacers 36, 38
After that, insert the mounting screw 1 through the washer 40.
2 and 14, it is assembled to the frame 10. Similar to the conventional platen drive mechanism shown in FIG.
meshes with The intermediate wheel is likewise rotatable about the intermediate axle 42. However, in the embodiment shown in FIGS. 2 and 3, the intermediate axle 42 is
The bottom portion 44 is made to have an enlarged diameter and is formed into a cylindrical shape with a stepped portion on the outer periphery. Then, a rubber spacer 46 is sandwiched between the bottom part 44 and the frame 10,
It is attached to the frame 10 with a mounting screw 50 passing through the center hole of the washer 48. The intermediate wheel 22 has such an intermediate axle 42 inserted into its central boss portion 52, and the enlarged diameter bottom portion 4 of the intermediate axle.
4 and fitted into the intermediate axle 42
It is prevented from coming off by a ring 54.

Therefore, according to the embodiment shown in FIGS. 2 and 3, even if the intermediate wheel 22 thermally expands, the rubber spacers 36 and 38 are deflected, and the motor gear 20 is
In addition, the rubber spacer 46 is bent, the intermediate axle 42 is collapsed, and the intermediate wheel 22 escapes from the platen gear 26, thereby making it possible to reduce the increase in the load torque applied to the motor 16.

Next, in FIGS. 4 and 5 showing other embodiments of the invention, the motor 16 has its flange 56 similar to the embodiment shown in FIGS. 2 and 3.
is sandwiched between rubber spacers 58 and 60, and is attached to the frame 10 with mounting screws 12 and 14 via a washer 62. The motor gear 20 at the tip of the motor shaft 18 of the motor 16 meshes with the intermediate wheel 22, causing the intermediate wheel 22 to rotate about the intermediate axle 64. In the embodiment shown in FIGS. 4 and 5, the intermediate axle 64 is formed into a cylindrical shape with an enlarged diameter end 66 and a stepped portion on the outer periphery. The flange 56 of the motor 16 is then attached to the flange 56 of the motor 16 by a mounting screw 70 passing through the center hole of the washer 68.
can be attached to. The intermediate axle 64 is inserted into the center boss portion 72 of the intermediate wheel 22, and the intermediate wheel 22 is inserted between the enlarged end portion 66 and the flange 56.
support.

Therefore, according to the embodiment shown in FIGS. 4 and 5, even if the intermediate wheel 22 thermally expands, the rubber spacers 58 and 60 will bend, the flange 56 will tilt, and the intermediate wheel 22 will move away from the platen gear 26. Since the torque escapes, the increase in the load torque applied to the motor 16 can be reduced.

Therefore, according to this invention, even if the intermediate wheel expands thermally due to temperature rise due to changes in the usage environment, the elastic member provided between the fixed member and the motor will deflect, reducing the load torque of the motor. can do.

Although a rubber spacer is used as the elastic member in the above embodiment, a resin spacer having elasticity may be used instead of the rubber spacer. Also, the motor 16 is attached to the frame 10 at two places,
Of course, it is not limited to two locations, but may be more than two locations.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing a conventional platen drive mechanism in a printer. FIGS. 2 and 3 show an embodiment of this invention, with FIG. 2 being a plan view showing the platen drive mechanism, and FIG. 3 being a side view thereof. FIGS. 4 and 5 show other embodiments of this invention, with FIG. 4 being a plan view showing the platen drive mechanism, and FIG. 5 being a side view thereof. 16... Motor, 22... Intermediate wheel, 26... Platen gear, 30... Platen, 36, 38, 46, 5
8,60...Rubber spacer.

Claims (1)

[Scope of utility model registration request] In a printing device that supports a motor with a fixed member and transmits the rotation of the motor to a driven member via an intermediate wheel, the motor deflects in response to the load from the intermediate wheel and escapes in a direction that reduces the load. A driving force transmission mechanism for a printing device, wherein an elastic member is provided between the fixed member and the motor.