JPH0315320Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a ribbon device for a thermal transfer printing machine such as a typewriter or printer.

[Prior Art] Conventionally, in the above-mentioned ribbon device, the printing head is moved between a printing position and a non-printing position by a solenoid, and a ribbon feeding gear provided on a carrier is engaged with a rack provided on the main body of the printing machine. It is known that the printing ribbon is fed by rotating a ribbon feed shaft as the printing ribbon moves.

[Problem that the invention attempts to solve]

The conventional ribbon device described above generates a large amount of noise due to the impact sound when the print head is displaced by the solenoid, and the ribbon feed shaft rotates even when the carrier moves without printing due to spacing etc. There was a drawback that the unused portion of the ribbon was fed and wasted.

The present invention is intended to prevent the noise caused by the impact sound of the solenoid mentioned above, and also to prevent wasteful feeding of the printing ribbon when the carrier moves without printing due to spacing or the like.

[Means for solving problems]

The ribbon device of the present invention includes a drive motor that can rotate in forward and reverse directions, a printing head that is set at a printing position by a spring, and a movement of the printing head from the printing position to a non-printing position against the spring. a ribbon feed shaft that feeds the printing ribbon; and a ribbon feed shaft that feeds the printing ribbon; A first one-way clutch is provided between the cam and the motor, and transmits the rotation to the cam only when the motor rotates in the other direction to move the print head from the printing position to the non-printing position. and a second one-way clutch on the carrier.

[Operation] When the motor is rotated in one direction (forward rotation), that rotation is transmitted to the ribbon feed shaft and the printing ribbon is automatically fed; when the motor is rotated in the other direction (reverse rotation), the rotation is transmitted to the ribbon feed shaft and the printing ribbon is automatically fed. , the cam is driven and the print head is automatically retracted from the printing position to the non-printing position against the spring.

Therefore, when printing, set the print head at the print position and rotate the motor in the normal direction to feed the printing ribbon.When moving the carrier without printing due to spacing, etc., the motor should be rotated once in the reverse direction. If the motor is stopped and the carrier is moved after the print head is evacuated to the non-print head, wasteful use of the print ribbon can be prevented during spacing and the like.

〔Example〕

The illustrated embodiment will be described below.

1 is a carrier, which has the shape of a planar rectangular box with an open top surface, and a slider 2 attached to a front plate 1a is slidably fitted into a rod 3;
The rod 4 is slidably fitted into bearing holes provided at the rear of the right side plates 1b, 1c, and is moved left and right in parallel with the platen 5 by a required drive mechanism (not shown).

Reference numeral 6 denotes a motor capable of forward and reverse rotation attached to the outer surface of the right side plate 1c of the carrier 1. Its output shaft is horizontally mounted inside a bearing frame 7 installed in the front side of the carrier 1, and a gear 8 is attached to the tip. are mated.

The bearing frame 7 has a support plate 7a formed by bending a metal plate to have a concave cross-section, and support plates 7b and 7c facing each other in parallel in the front and rear parts of the support plate 7a. The spacing is approximately half that of the support plates 7a and 7b, and these support plates 7a to 7c are connected to the left and right side plates 1b and 1c of the carrier 1.
is placed parallel to.

Reference numerals 9 and 10 denote rods horizontally suspended vertically and parallel to each other between the support plates 7a and 7b, and the gear 8 is disposed between these rods.

11 and 12 are gears each rotatably supported on the rod 9, and a one-way spring clutch 13
At the same time, gear 11 is connected to gear 8.
It is engaged with the upper circumference of the

14 and 15 are gears each rotatably supported on the rod 10, and a one-way spring clutch 16
gear 14 to gear 8.
It is engaged with the lower circumference of the.

Reference numerals 17 and 18 denote shafts that are vertically and parallelly opposed between the support plates 7a and 7c and are rotatably supported horizontally, with the shaft 17 facing the rod 9 and the shaft 18 facing the rod 10 in the front and rear directions, respectively.

Gears 19 and 20 are attached to the shaft 17.
and mesh the gear 19 with the gear 12, and the left and right side plates 1b,
A gear 20 is meshed with a gear 22 fitted on a shaft 21 rotatably supported between 1c.

23 is a cam fitted onto the shaft 21, which is disc-shaped and has a large diameter part 23a and a small diameter part 23 around it.
b for displacing the print head 24 between a printing position and a non-printing position.

25 is a gear fitted to the shaft 18;
It is meshed with the gear 15.

Furthermore, a bevel gear 27 for rotating the ribbon feed shaft 26 is fitted into the tip portion of the shaft 18 that protrudes to the left beyond the support plate 7a.

The print head 24 has a vertically long rectangular plate shape,
It is attached to the holder 28.

The holder 28 is rotatably supported by a support shaft 30 on support plates 29, 29 screwed to both rear corners of the carrier 1, and its lower end is attached to the carrier 1.
The carrier 1 faces an opening 31 formed in the opening 31, and is biased to rotate in a predetermined direction (clockwise in FIG. 2) by a tension spring 32 stretched between the lower end of the carrier 1 and the carrier 1.

Reference numeral 33 denotes a support frame formed by bending a long and narrow plate into a concave shape, and its both ends are rotatably supported by support shafts 34, 34 on the left and right sides of the holder 28.

Reference numeral 35 denotes a head lever in the form of an elongated plate, whose rear end bent at right angles is screwed to the support frame 33, and the cam follower 36 attached to the front end is connected to the cam 2.
3 is engaged.

A ribbon holder 37 is attached to the upper side of the carrier 1, and a printing ribbon 39 loaded in a ribbon cassette 38 placed on the ribbon holder is stretched over the rear side of the printing head 24.

When the printing head 24 is in the printing position (solid line in FIGS. 2 and 3) in which the printing ribbon is pressed against the paper 40 wound around the platen 5, the cam follower 36 is engaged with the small diameter portion 23b of the cam 23.

Further, the ribbon feed shaft 26 is rotatably supported on the upper side of a rod 41 established on the bottom plate 1d of the carrier 1, and a take-up reel (not shown) of the ribbon cassette 38 is integrally supported on the upper side of the rod 41. They are fitted together so that they rotate.

A bevel gear 42 is rotatably supported on the lower side of the rod 41, and is connected to the ribbon feed shaft 26 by a spring clutch 43 and meshed with the bevel gear 27.

Therefore, when the gear 8 rotates in a predetermined direction (clockwise in FIG. 2) due to the forward rotation of the motor 6,
Gears 11 and 14 each rotate in a predetermined direction,
Gear 15 connected to gear 14 by one-way spring clutch 16 rotates, but gear 1
The gear 12, which is disconnected from the one-way spring clutch 13, is at rest.

As the gear 15 rotates, the ribbon feed shaft 26 rotates via the gear 25 and bevel gears 27 and 42, and winds up the used portion of the printing ribbon 39.

Also, due to the reverse rotation of the motor 6, the gear 8
When rotates in a predetermined direction (counterclockwise in FIG. 2), gears 11 and 14 rotate in predetermined directions, and gear 11 and one-way spring clutch 1
The gear 12 connected by the gear 3 rotates, but the gear 15, which is disconnected from the gear 14 by the one-way spring clutch 16, is at rest.

Due to the rotation of the gear 12, the gears 19, 2
1 and 22, the cam 23 rotates and the large diameter portion 23
engages the cam follower 36 and pushes it forward, causing the print head 24 to release the tension spring 32
Tilt the printing ribbon 39 forward against the paper 40.
It is displaced to a non-printing position (dashed line in FIG. 3) away from the printer.

Then, as the small diameter portion 23b engages with the cam follower 36 due to the continued rotation of the cam 23, the print head 24 is returned to the printing position by the bias of the tension spring 32.

Therefore, when printing, it is sufficient to set the printing head 24 at the printing position and feed the printing ribbon 39 by rotating the motor 6 in the forward direction, and when moving the carrier 1 without printing due to spacing etc. After the motor 6 is once rotated in the reverse direction to displace the print head 24 to the non-printing position, the motor 6
It is sufficient to stop the printer and move the carrier 1, thereby preventing unused portions of the printing ribbon 39 from being fed unnecessarily during spacing or the like.

As is clear from the above, according to the present invention, the print head is displaced between the printing position and the non-printing position by a cam driven by a motor that can rotate in forward and reverse directions. This is extremely small compared to the impact noise that occurs when displacing the print head using a solenoid, and there is no noise generated as in conventional methods.

In addition, since both the printing head and the ribbon feed shaft are driven by the forward and reverse rotation of one motor, and these are not driven separately by two motors, it is therefore more economical; It is possible to avoid the disadvantages of increasing the size and weight of the carrier by installing this motor.

Furthermore, the printing ribbon is fed by the unidirectional rotation of the motor mounted on the carrier, which can rotate in forward and reverse directions, rather than by the movement of the carrier.
When the carrier is moved without printing due to spacing or the like, this motor can be kept stopped, and there is no need to waste the unused portion of the printing ribbon by feeding it.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 1 is a plan view, FIGS. 2 to 4 are cross-sectional views of main parts at the positions of the line, - line, and - line in FIG. 1, and FIG. 5 is a perspective view. . 6... Motor, 23... Cam, 24... Printing head, 39... Printing ribbon, 26... Ribbon feed shaft, 1... Carrier, 13, 16...
One-way spring clutch, 32... tension spring.

Claims (1)

[Claims for Utility Model Registration] A driving motor 6 capable of forward and reverse rotation, a printing head 24 set at a printing position by a spring 32, and a printing head 24 set at a printing position by pushing the printing head 24 against the spring 32. a cam 23 that can be displaced from the printing ribbon to a non-printing position; a ribbon feed shaft 26 that feeds the printing ribbon 39; Ribbon feed shaft 26 rotates only when the direction rotates.
A first one-way clutch 16 is provided between the cam 23 and the motor 6, and transmits the rotation to the cam 23 only when the motor 6 rotates in the other direction. A ribbon device for a thermal transfer printing machine, characterized in that the carrier 1 is provided with a second one-way clutch 13 for displacing the ribbon from a printing position to a non-printing position.