JPS6273968A - Mechanism for driving movable member in printing apparatus - Google Patents

Abstract

PURPOSE:To reduce the total thickness or external size of a printing apparatus without protruding a drive source to the periphery of a platen, by providing a platen having a hollow part, the drive source housed in said platen and an intermediate transmission means transmitting the operation of the drive source to the outside of the platen to drive a movable member. CONSTITUTION:A motor 2 is supported without contacting the inner peripheral surface of the hollow pipe 1a of a platen 1. One end of the bracket 3 for supporting the motor 2 is fixed at the surface 2b having a motor shaft 2a protruded therefrom and the other end thereof is fixed to the hole of a frame 4. Further, the pinion gear 6 mounted on the motor shaft 2a, the intermediate gear 7 supported by the shaft 8 fixed to the frame 4 in a freely revolvable manner and the platen gear 9 meshed with the intermediate gear 7 are provided and the platen gear 9 is engaged with the opening part provided at the end part of the hollow pipe 1a of the platen 1. When the motor shaft 2a is rotated, the rotation thereof is transmitted to the intermediate gear 7 from the pinion gear 6 and, further, the platen gear 9 also rotates and, by this mechanism, the platen 1 is rotated to perform paper feed.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a drive mechanism for movable members in printing devices such as printers and electronic typewriters.
In particular, the present invention relates to the structure of a drive unit that moves movable members such as a platen and a carriage in a paper feeding mechanism or a carriage moving mechanism.

<Prior Art> Printing devices such as printers and electronic typewriters are generally equipped with items such as platens and carriages that must be movable in order to print. In particular, the platen and carriage are directly involved in printing quality and printing speed, and play an important role in the printing device. Mechanisms for driving the platen and carriage include a paper feeding mechanism and a carriage moving mechanism.

A conventional paper feeding mechanism has a core rod, an end of which is rotatably supported by a frame via a bearing, a motor placed behind or below the platen, and this motor. It consisted of belts, gears, etc. that transmitted the rotation of the platen to the platen.

In addition, the conventional carriage moving mechanism includes a wire fixed to a carriage slidably attached to the main shaft, and a wire drum that rotates to wind up the wire and move the carriage along the main shaft. It consisted of a motor that drove this wire drum.

<Problems to be Solved by the Invention> Since the motor in the paper feeding mechanism described above must drive the platen, it needs to be placed near the platen. However, if the motor is placed around the platen, it will inevitably protrude to the rear and downwards of the platen, and if it protrudes in the vertical direction of the platen, the total thickness of the printing device will increase. In some cases, there was a problem in that the external size became large.

Further, unlike a wire or a wire drum, the motor in the carriage moving mechanism must be placed outside the carriage movement area, and inevitably protrudes into the vicinity of the carriage movement area.

For this reason, this motor also has the problem of being disposed so as to overlap the platen or protruding to the outside of the carriage movement area, thereby increasing the external size of the printing device.

In particular, in recent years there has been a demand for smaller and lighter printing devices, and in order to meet the demands of such consumers, it has been necessary to provide smaller and lighter printing devices.

Means for Solving Problems> The present invention provides a platen having a hollow portion, a drive source housed inside the platen, and a drive source that transmits the operation of the drive source to the outside of the platen to drive a movable member. The present invention is characterized by comprising an intermediate transmission means that performs the following steps, and solves the problems of the conventional example.

<Example> The present invention will be described in detail below based on the drawings.

FIG. 11 is a sectional view showing a paper feeding mechanism according to an embodiment of the present invention.

Reference numeral 1 denotes a platen, which is composed of a hollow pipe 1a made of metal or the like, and a rubber roll 1b fixed to the outer peripheral surface of the hollow pipe 1a.

Reference numeral 2 denotes a motor as a driving source, and in this embodiment, a two-unit type motor is used. This motor 2 is supported without contacting the inner peripheral surface of the hollow pipe 1a of the platen 1.

3 is a bracket for supporting the motor 2, one end of which is connected to a surface 2b from which the motor shaft 2a of the motor 2 projects.
The other end is press-fitted into a hole in the frame 4 or fixed by a screw or the like.

5 is a motor shaft holder made of resin or the like, and has a cylindrical shape. By passing the motor shaft 2a through the center of the motor shaft receiver 5, the motor shaft 2a is prevented from tilting.

6 is a pinion gear attached to the motor shaft 2a, 7 is an intermediate gear rotatably supported by a shaft 8 fixed to the frame 4, and 9 is a platen gear that meshes with the intermediate gear. This pinion gear 6 and intermediate gear 7 are
A part of the intermediate gear 7 fits into the bracket 3 through a notch 3a provided in the bracket 3. Further, the platen gear 9 is fitted into the end opening of the hollow pipe 1a of the platen 1 by a press-fit cap, and its inner circumferential surface rotatably contacts the outer circumferential surface of the bracket 3, so that it also plays the role of a bearing. .

10 is a main shaft provided parallel to the platen 1, and 11 is a carriage that moves along the main shaft 10.

In the paper feeding mechanism configured as described above, when the motor shaft 2a of the motor 2 rotates, the rotation is transmitted from the pinion gear 6 to the intermediate gear 7, which also rotates the platen gear 9, which rotates the platen 1 and feeds the paper. conduct.

In this embodiment, the intermediate gear 7 is used to transmit the rotation of the pinion gear 6 to the platen gear 9, but a timing belt or the like may also be used.

Further, in order to dissipate the heat generated by the motor 2, it is desirable to provide a heat radiation hole in the hollow vibrator 1a. Furthermore, it is also possible to use a hollow vibrator 1a in which only the portion where the motor 2 is housed is hollow.

FIG. 2 is a sectional view showing a carriage moving mechanism according to an embodiment of the present invention.

A platen 21 is composed of a hollow vibrator 21a and a rubber roll 21b, as in the previous embodiment.

Reference numeral 22 denotes a motor as a driving source, which is also supported without contacting the inner circumferential surface of the hollow vibrator 21a, as in the previous embodiment.

23 is a bracket for supporting the motor 22;
As in the previous embodiment, one end is fixed to the motor 22 and the other end is fixed to the frame 24.

25 is a pinion gear attached to the motor shaft 22a, 26 is an intermediate gear rotatably supported by the shaft 27, and 28 is an internally toothed wire drum having teeth formed on its inner peripheral surface.

The bracket 23 is provided with a notch 23a, and the shaft 27 is fixed near the notch 2.3a.

A portion of the intermediate gear 26 supported by the shaft 27 enters into the bracket 23 through the notch 23 a of the bracket 23 and meshes with the pinion gear 25 . Further, the wire drum 28 is supported in rotatable contact with the outer periphery of the bracket 23, includes an intermediate gear 26, etc., and meshes with the intermediate gear 26 through its internal teeth.

29 is a bushing attached to the outer periphery of the bracket 23, and 30 is a bearing made of Teflon, nylon, etc., which is fixed to the hollow vibrator 21a of the platen 21 by press-fitting or the like and is in contact with the outer periphery of the bushing 29. This bushing 29 may be replaced by a bracket 23 or a bearing 30.

31 is a carriage, 32 is a main shaft that supports the carriage 31 in a slidable manner, 33 is a wire that is housed in the carriage 31 and is wound up by the wire drum 28, and 34 is a wire that is oriented in the direction in which the carriage 31 moves. This is a pulley for changing.

In this embodiment, the rotation of the motor shaft 22a is transmitted to the wire drum 28 via the pinion gear 25 and the intermediate gear 26, and as the wire drum 28 rotates, the wire 33 is wound up and the carriage 31 is moved.

Since the platen 21 in this embodiment is in contact with the bush 29 via the bearing 30, it rotates regardless of the rotation of the wire drum 28.

In this embodiment as well, the hollow vibrator 21a may be provided with heat radiation holes, or a hollow vibrator may be used in which only the portion where the motor 22 is housed is hollow.

<Effects of the Invention> According to the present invention, since the driving source does not protrude around the platen, the total thickness or external shape of the printing device can be reduced, and the printing device can be made smaller and lighter. .

In addition, intermediate gears have a higher degree of freedom in placement than motors, and their positions can be changed to above and below the platen, making it easy to change the design and apply it to different models. can do.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a paper feeding mechanism according to an embodiment of the invention, and FIG. 2 is a sectional view showing a carriage moving mechanism according to an embodiment of the invention. 1.21... platen, 2, 22... motor, 3.
23... Bracket, 4, 24... Frame, 6.
25... Pinion gear, 7.26... Intermediate gear, 9
...Platen gear, 28...Wire drum. Figure z Procedure Amendment Writing Method) February 73, 1986 Mr. Michibu Uga, Commissioner of the Patent Office, 51
, Indication of the case 1985 Permanent Application No. 215994 2, Drive mechanism of the movable member in the name printing device of the invention 3, Person making the amendment 4, Date of the amendment order ・-
, 2 January 28, 1985 (shipment date) 5. No number of inventions increased by amendment 6. Drawings subject to amendment

Claims (1)

[Scope of Claims] 1) A platen having a hollow portion, a drive source housed inside the platen, and an intermediate transmission means for transmitting the operation of the drive source to the outside of the platen to drive a movable member. A drive mechanism for a movable member in a printing device, comprising: 2) A drive mechanism for a movable member in a printing device according to claim 1, wherein the drive source is fixed to an external frame without contacting the platen. 3) Claim 2, wherein the drive source is fixed to the external frame via a bracket.
A drive mechanism for movable members in a printing device. 4) The intermediate transmission means includes a platen gear fixed to the platen and rotated by the drive source, and as the platen gear rotates, the platen rotates and the paper is fed. A drive mechanism for a movable member in the printing device according to paragraph 1. 5) The intermediate transmission means includes a wire drum that winds a wire attached to the carriage and is rotated by the drive source, and the carriage is moved by the rotation of the wire drum. A drive mechanism for a movable member in the printing device according to item 1.