JPH01224563A - Backlash adjusting device in gear transmission mechanism - Google Patents

Abstract

PURPOSE:To surely transmit power to the first driven mechanism and automatically adjust the backlash between the trailing bevel gear and the driving bevel gear of the second driven mechanism by meshing the driving bevel gear with the driven bevel gear by the urging power which a drive shaft turn-urges the driven spur gear. CONSTITUTION:After the bearing part 32a of an output shaft 11 is fitted into a bearing hole 31, a driving body 14 is inserted and fixed at the outer edge part of the output shaft 11, and then a driving spur gear 12 is surely meshed with a driven spur gear 15. Then, the cylindrical bearing part 32a is installed in shiftable ways into the bearing hole 31 by tightening the stepped screws 35 and 36 inserted into the respective screw insertion holes 33 and 34 on a side wall 2a onto the motor installation piece 32b of a supporting body 32. When a spring is laid in this state between the stepped screw 35 and a projecting piece 37, the bearing part 32a is shifted upwardly along the bearing hole 31 by the urging force, and a driving bevel gear 13 on the output shaft 11 is automatically meshed with a driven bevel gear 20, and the backlash between the both bevel gears 13 and 20 can be adjusted.

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention provides a first driven mechanism equipped with a driven spur gear, a second driven mechanism equipped with a driven bevel gear, and a method for driving each driven mechanism. A drive shaft to be rotated; a drive spur gear that is rotatably mounted on the drive shaft and meshes with the driven spur gear; and a drive bevel gear that is rotatably mounted on the drive shaft and meshes with the driven bevel gear. The present invention relates to a gear transmission mechanism equipped with a gear transmission mechanism.

(Prior Art) Conventionally, the carriage of an evening print printer is provided with a ribbon lift mechanism for lifting the printing ribbon from a rest position to a printing position facing the platen, and a ribbon lift mechanism for winding up the printing ribbon. A ribbon winding mechanism is provided, and the rotation of the motor attached to the carriage is transmitted to the ribbon lift mechanism through engagement between a driving spur gear attached to the output shaft of the motor and a driven spur gear of the ribbon lift mechanism. The information is transmitted to the ribbon winding mechanism through engagement between a driving bevel gear mounted on the output shaft of the motor and a driven bevel gear of the ribbon winding mechanism. In addition, the dimensional accuracy of the distance between the output shaft of the motor and the driven spur gear is ensured, making it unnecessary to adjust the backlash between the two-handed gears, and the mounting position of the drive bevel gear is adjusted along the output shaft. The backlash between the umbrella gears can be adjusted by adjusting the gears.

(Problem to be Solved by the Invention) However, in the above-mentioned conventional configuration, the drive bevel gear and the drive spur gear are integrally formed, and the integral part is mounted on the output shaft so that the position can be adjusted, and the adjustment position cannot be adjusted. Since it is fixed to the output shaft with a screw, if the amount of adjustment of the drive bevel gear is increased, the amount of engagement between the drive spur gear and the driven spur gear will be insufficient, resulting in power transmission to the ribbon lift mechanism. There is a problem in that not only is the adjustment screw incomplete, but it is also necessary to loosen and tighten the adjustment screw, which is a troublesome task.

This application was made in order to solve the above-mentioned problems, and its first purpose is to be able to reliably transmit power to a first driven mechanism such as a ribbon lift mechanism, and to enable reliable transmission of power to a first driven mechanism such as a ribbon lift mechanism. An object of the present invention is to provide a backlash adjustment device capable of automatically adjusting bank lash between a driven bevel gear and a driving bevel gear. A second object is to provide a backlash adjustment device that can achieve the intended purpose with an extremely simple configuration.

(Means and operations for solving the problem) In order to achieve the above object, in the device of the present invention, the drive shaft is rotationally biased along an arc centered on the rotation center of the driven spur gear,
The driving bevel gear is meshed with the driven bevel gear by the biasing force.

Therefore, there is no need to perform the troublesome work of adjusting the position of the drive bevel gear on the shaft, and the clash between the bevel gears can be automatically adjusted.
It is possible to avoid the possibility that the meshing position of the two-handed gears will fluctuate, and it is possible to reliably transmit power between the two-handed gears.

Further, the bearing formed in the frame so as to extend along the circular arc has a hole, the bearing is movably installed in the hole, and a support body rotatably supports the drive shaft, and the support body is provided with a hole. By providing a biasing means for biasing in a predetermined direction, the above-mentioned automatic adjustment of backlash, etc. can be achieved with an extremely simple configuration and can be manufactured at low cost.

(Embodiment) Hereinafter, an embodiment of a typewriter embodying the present invention will be described in detail with reference to the drawings. As shown in FIG. 2, a ribbon holder 3 is swingably supported by a support shaft 3a on a carriage 2 that is movable along the longitudinal direction of the platen 1, and a printing ribbon R is mounted on the holder 3. A ribbon cassette 4 and a spool 5 wound with a correction ribbon C are attached. On one side of the carriage 2 is a ribbon lift mechanism 6 as a first driven mechanism.
A ribbon lift cam 7 as shown in Publication No. 491 is attached to a support shaft 8.
The holder 3 is rotatably supported by the ribbon lift cam 7, and the holder 3 is provided with a cam follower 9 that engages with the ribbon lift cam 7.
As the ribbon lift cam 7 rotates, the holder 3 is swung via the cam follower 9, so that the exposed portion of the print ribbon R or the exposed portion of the correction ribbon C moves from the lower rest position to the upper position facing the platen 1. It is swung to the printing position.

As shown in FIGS. 1 and 3, the side wall 2 of the carriage 2
A motor 1o is mounted on the inner surface of a, and its output shaft 11 penetrates the side wall 2a and projects outward. This voice power axis 1
1 constitutes a drive shaft.

A driving body 14 which is integrally formed with a driving spur gear 12 and a driving bevel gear 13 is mounted on the output shaft 11 so as to be integrally rotatable. In between, a driven spur gear 15A is rotatably supported by a support shaft 15a, and the rotation of the driving spur gear 12 is transmitted to the ribbon lift cam 7 via the driven spur gear 15 and the transmission gear 7a.

As shown in FIG. 2, a support stand 16 protruding from one side of the carriage 2 has a ribbon winding mechanism 17 as a second driven mechanism.
A winding shaft 18 that can be connected to a well-known winding spool (path shown) in the ribbon cassette 4 is provided in a protruding manner, and when the winding shaft 18 is rotated in one direction, the ribbon cassette 4 Print ribbon R on the inner take-up spool
is wound up. A rotary shaft 19 for transmitting the power of the motor 10 to the winding shaft 18 is rotatably supported on the support base 16 around an axis perpendicular to the support base 16, and a transmission spur gear 19a is formed at the upper end of the rotary shaft 19. , meshes with the spur gear 17a of the winding mechanism 17. Further, a driven bevel gear 20 that meshes with the driving bevel gear 13 is integrally formed at its lower end.

Therefore, in this embodiment, when the output shaft 11 of the motor IO is rotated in the normal direction, the rotation is transmitted to the ribbon lift mechanism 6 via the driving spur gear 12 and the driven spur gear 15, Based on the actuation, the printing ribbon R or the correction ribbon C is lifted to a printing position opposite the platen 1. Further, the normal rotation motion of the output shaft 11 is transmitted to the ribbon winding mechanism 17 via the drive bevel gear 12, the driven bevel gear 20, and the transmission spur gear 19a, and each spur gear 17a, 17b of the ribbon winding mechanism 17 , 17c, the used printing ribbon R is wound up by the winding shaft 18 rotated through the winding shaft 18.

The ribbon winding mechanism 17 has the same structure as that described in Japanese Patent Application Laid-open No. 123569/1983, written by the same applicant as the applicant of this application, so please refer to that if necessary.

Next, the backlash adjustment device in this embodiment will be explained in detail. As shown in Figures 1 and 3,
A support shaft 15 of a driven spur gear 15 is mounted on the side wall 2a of the carriage 2.
A hole 31 is formed in the bearing extending along an arc centered at a, and a support body 32 is attached to the motor 10. The support body 32 includes a cylindrical bearing part 32 a that rotatably supports the output shaft 11 on its central axis and is movably fitted into the hole 31 , and a cylindrical bearing part 32 a that is movably fitted into the hole 31 . A pair of motor mounting pieces 32b are provided that protrude from the top.

Each motor mounting is opposed to the piece 32b, and a screw insertion hole 33.34 is formed in the side wall 2a, and a pair of stepped screws 35.36 passing through the insertion hole 33.34 are screwed into the piece 32b. has been done. Further, a spring 38 is hung between one step screw 35 and the protruding piece 37 of the side wall 2a, and its urging force causes the drive bevel gear 13 to mesh with the driven bevel gear 20, thereby adjusting the backlash. has been done.

That is, in this embodiment, the bearing of the output shaft 11 is
After fitting the bearing a into the hole 31, the driving body 14 is inserted and fixed to the outer end of the output shaft 11, so that the driving spur gear 12 is reliably engaged with the driven spur gear 15. Then, the stepped screws 35. are inserted into the respective screw insertion holes 33.34 of the side wall 2a.
36, the motor of the support body 32 is fastened to the piece 32b, so that the cylindrical bearing part 32a is fixed to the hole 31.
movably mounted inside. In this state, if a spring 38 is hung between one step screw 35 and the projection piece 37, the bearing part 32a will be moved upward in FIG. 3 along the hole 31 due to its biasing force. Drive bevel gear 1 on output shaft 11
3 is automatically meshed with the driven bevel gear 20 to adjust the bank lash between the bevel gears 13 and 20. Thereby, the attachment of the motor 10 to the side wall 2a can be easily completed. And each gear on the drive side 12°13
Ensure meshing between the gears 15 and 20 on the driven side,
Power transmission between the motor 10 and each driven mechanism 6, 17 can be ensured. In addition, in this embodiment, the bearing has holes 31. Since it is only necessary to provide the support body 32, the spring 38, etc., the number of parts can be reduced and manufacturing can be done at low cost.

Note that this invention is not limited to the above embodiments,
The backlash adjustment device of the present invention can be implemented in a drive shaft that is indirectly rotated by a motor via a power transmission mechanism, or can be implemented in a gear transmission mechanism in devices other than typewriters.

(Effects of the Invention) As described in detail above, the present invention can reliably transmit power to a first driven mechanism such as a ribbon lift mechanism, and can also ensure the transmission of power between the driven bevel gear and the driving bevel gear of the second driven mechanism. It is possible to automatically adjust the backlash between
The structure for this purpose is extremely simple and can be manufactured at low cost, which is an excellent effect.

[Brief explanation of the drawing]

Fig. 1 is a partially exploded perspective view showing the main parts of a typewriter embodying the present invention, Fig. 2 is a side view showing the carriage of the typewriter, and Fig. 3 is a partially enlarged side view showing the meshing state of each gear. It is a diagram. 2a... Side wall as a frame, 6... Ribbon lift mechanism as a first driven mechanism, 11... Output shaft as a drive shaft, 12... Drive spur gear, 13... Drive bevel gear, 15... Driven spur gear, 17... Ribbon winding mechanism as second driven mechanism, 20... Driven bevel gear, 31
. . . Bearing is a hole, 32 . . . Support body, 38 . . . Spring as biasing means.

Claims (1)

[Claims] 1. A first driven mechanism (6) equipped with a driven spur gear (15), a second driven mechanism (17) equipped with a driven bevel gear (20), and each driven mechanism (6, 17). ); and a drive spur gear (11) that is rotatably attached to the drive shaft (11) and meshes with the driven spur gear (15).
12) and is rotatably mounted on the drive shaft (11),
A gear transmission mechanism including a drive bevel gear (13) that meshes with the driven bevel gear (20), wherein the drive shaft (11) extends along an arc centered on the rotation center of the driven spur gear (15). The driving bevel gear (13) is rotationally biased, and the driven bevel gear (20) is rotated by the biasing force.
A backlash adjustment device for a gear transmission mechanism, characterized in that the backlash adjustment device is meshed with the gear transmission mechanism. 2. A bearing hole (31) formed in the frame (2a) so as to extend along the circular arc, and the bearing hole (31)
a support (32) which is movably mounted in the interior and rotatably supports the drive shaft (11);
2. The backlash adjustment device for a gear transmission mechanism according to claim 1, further comprising a biasing means (38) for biasing the gear 2) in a predetermined direction.