JPH0117703Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a gear device that converts reciprocating motion into rotary motion, and more specifically, it always converts both the reciprocating motion of a printer stand equipped with a printer into rotary motion in one direction. This invention relates to a double one-way gear device for feeding printing ribbon, which feeds the printing ribbon even when the printer moves backward.

For example, in a printing machine that performs printing by interposing a printing ribbon between the printer head and the printing card, a combination of a one-way gear and a rack as seen in Utility Application No. 57-115419 (Utility Model Application No. 59-20028) is used. By using a ribbon feeding mechanism consisting of a printer, the printing ribbon is sequentially fed as the printer moves along the card surface. When moving backwards toward the destination, the one-way gear is disengaged and does not send the printing ribbon. Therefore, the printer cannot print during the return movement, and printing is performed only in the outward direction. Due to this relationship, there was a problem that the printing speed was slow.

The above problem can be solved by, for example, adding one more rack and switching the engagement between the pinion on the ribbon feeding member side and these two racks on the outward and return passes, or,
This problem can be solved by adding an intermediate gear that easily meshes with the pinion, and by disengaging and engaging the intermediate gear with the pinion, so that the ribbon feeding member is constantly fed and rotated in one direction regardless of reciprocating motion. However, with all of these devices, it is very difficult to smoothly change the meshing of the gears and gears, and
There are drawbacks such as the heavy load placed on the rack and gear during switching, which can easily lead to tooth breakage, and this can cause various problems such as ribbon feeding being interrupted, making it impossible to print correctly, and frequent breakdowns. It was hot.

The present invention was developed in view of the above points, and its purpose is to smoothly convert the reciprocating motion of the printer stand into rotation in one direction without changing the engagement between the gear and the rack. The object of the present invention is to provide a double one-way gear device for feeding printing ribbon that is devised so that the printing ribbon can always be fed in one direction when the printer table is moved back and forth. In order to do this, a spring is wound in a coil around the circumference of a one-way gear device that rotates only when the printer table moves forward and does not rotate when it moves backward, and this spring releases when it moves forward. The one-way gear device is rotated in one direction by engagement with the rack to feed the printing ribbon, and during the backward movement, the one-way gear device is rotated by the tightening action of the spring in the same manner as in the forward movement. The print ribbon is rotated in the same direction to feed the printing ribbon in the same direction.

Next, a preferred embodiment of the present invention described above will be described in detail with reference to the accompanying drawings.

In the drawings, FIG. 1 is a plan view of a double one-way gear device for feeding a printing ribbon according to the present invention, and shows
Fig. 2 is a front sectional view of the main part, Fig. 3 is a plan view showing the operating state of the present invention during outward movement, and Fig. 4 is a front view of the main part.
The figure is a plan view showing the operating state during return trip operation.
The figure is an exploded front view showing a part of the one-way gear device used in the present invention in cross section, and Figures 6 and 7 are front views showing the engaged and disengaged state of the clutch mechanism housed inside the one-way gear device. In the illustrated embodiment, the one-way gear proposed in the above-mentioned Utility Model Application No. 115419/1980 is used as is as the above-mentioned one-way gear device.

The structure of the one-way gear device will be explained based on the description in FIGS. 2 and 5. Reference numeral 10 indicates a mounting shaft 11a mounted on the upper surface of the mounting portion 11 on the printer stand 34 side.
This is a rotary gear which is rotatably mounted using a rotary gear, and a boss 12 having a two-stage structure consisting of a small diameter part 12a and a large diameter part 12b is protruded concentrically from the upper surface of the gear. 13... are engagement grooves recessed in the small diameter portion 12a, and the inner bottom surface of each of these engagement grooves 13 is an inclined surface 13a.
It has become. Reference numeral 14 designates an intermediate ring loosely fitted into the small diameter portion 12a, and reference numeral 15 designates a drive gear formed on the upper surface of the intermediate ring 14. Further, the intermediate ring 14 is provided with leg teeth 16 which are fitted into the respective engagement grooves 13 and project downward. As shown in FIGS. 6 and 7, each of these leg teeth 16 is formed to be narrower than the groove width of the engagement groove 13, and has a lower end surface 16a with the same slope as the inner bottom inclined surface 13a of the engagement groove 13. It is formed into a surface and has a structure in which it is slidably in contact with the inclined surface 13a. Next, 17
18 is a driven cylinder having a hollow structure that is rotatably fitted in the upper large diameter portion 12b of the rotating gear 10;
The intermediate ring 1 is attached to the ceiling surface of the driven cylinder 17.
This is an interlocking gear provided in a circular shape opposite to the drive gear 15 of No. 4, and both gears 15 and 18 constitute a clutch mechanism that can be freely engaged and disengaged. Reference numeral 19 denotes an operating shaft protruding from the ceiling surface of the driven cylinder 17, and the printing ribbon feeding roller 35 of the printing machine operated by the one-way gear device configured as described above is attached to this operating shaft 19. It is designed to operate by rotating.

The above-described one-way gear device meshes the rack 20 with the rotating gear 10 as shown in FIGS. 2 to 4,
When the holding member 11 is moved forward along this rack 20 in the direction of arrow X in FIGS. 2 and 3, the rotating gear 10 rotates clockwise (in the direction of arrow R in FIG. ), the intermediate ring 14 is pushed up along the inclined surface of the engagement groove 13 in the direction of the arrow RA in FIG. Also, the holding member 11 can be moved in the direction of arrow Y in FIG.
The rotating gear 10 moves back in the direction of arrow L in FIG.
When the gear rotates in the opposite direction, the intermediate ring 14 descends and disconnects the driving gear 15 from the interlocking gear 18, so that the driven cylinder 17 does not rotate.

Next, the essential structure of the present device used with the one-way gear device having the above configuration will be explained.

In the figure, reference numeral 21 denotes a feed cylinder loosely fitted to the circumferential surface of the driven cylinder 17 with an interval, and a feed gear 2 formed with a larger diameter than the rotary gear 10 is provided on the bottom circumferential surface of the feed cylinder.
2 is installed. Reference numeral 23 designates the holding member 11 so as to mesh with the rack 20 and the feed gear 22.
This intermediate gear is rotatably attached to the upper surface of the rotary gear 10 with a shaft 23a, and this gear 23 always rotates the feed cylinder 21 in the opposite direction to the rotation of the rotary gear 10. In addition, 24 has one end connected to the notch groove 2 of the feed cylinder 21.
1a, and the other end is wound in a coil around the circumferential surface of the driven cylinder 17 as shown in FIGS. 2 to 5. When the driven cylinder 17 rotates in the opposite direction to the feed rotation (during outward movement), the bullet is released, and conversely, the feed cylinder 21 moves the driven cylinder 17 as shown in FIG.
When rotating in the same direction as the feed rotation direction (during return movement), the driven cylinder 17 is wound to the left in the drawing so that the driven cylinder 17 is tightened and rotated together.

Therefore, according to the double one-way gear device used in the present invention, when the holding member 11 or the rack 20 moves forward, the clutch of the one-way gear device engages and rotates the driven cylinder 17 in one direction.
When the holding member 11 or the rack 20 moves back,
As the feed cylinder 21 rotates, the spring 24 tightens the circumferential surface of the driven cylinder 17, and the clutch of the one-way gear device is disengaged, so that the driven cylinder 1
7 can be fed and rotated by the spring 24 in the direction of rotation of the feed cylinder 21 as shown by the arrow in FIG. Movement of driven cylinder 1
7 can be converted into rotation in one direction.

Next, the main structure of the present invention in which the above double one-way gear device is used in a ribbon feeding mechanism of a printing machine will be explained with reference to FIGS. 1 and 2.

In the figure, 30 is a grooved cam shaft 31 installed on the machine frame 40.
33 is a dot printer mounted on the printer stand 30, and 34 is a ribbon cassette similarly mounted on the printer stand 30. After the endless printing ribbon PR stored in the ribbon cassette 34 is wrapped around the printer head 33a, it is passed through the feed roller 35 and the tension roller 3.
6 into the cassette and then pulled out to the printer head 33a side, and this feed roller 35 is attached to the operating shaft 19 of the driven cylinder 17 as shown in FIG. to feed the ribbon. Further, the rack 20 described above is connected to one end side of a guide plate 37 installed on the machine frame 40 in order to guide the rear end of the printer stand 30, and also supports the gear device described above. The support member 11 is fixed to the printer stand 30.

As described above, in the printing machine using the double one-way gear device for feeding the printing ribbon of the present invention as a feeding means for the printing ribbon PR, the printing ribbon PR can be constantly fed in one direction as the printer stand 30 moves back and forth. From this, it has become possible to double the printing speed by driving the printer 33 for printing in both directions.

The double one-way gear device for feeding the printing ribbon according to the present invention can convert the reciprocating motion based on the reciprocating printing operation of the printer into a unidirectional ribbon feeding motion as described above. Since the configuration is such that the feed rotation is performed by a one-way gear device, and the feed rotation on the return path is performed using the tightening action of the spring, switching is performed extremely smoothly and efficiently, and the driven cylinder The printing ribbon can be rotated accurately in one direction to constantly feed the printing ribbon in one direction. Therefore, the printer can print on both the outward and return passes to speed up printing. In addition, the configuration of the gear device is very simple and practical, as it only requires adding a feed cylinder with a feed gear, an intermediate gear, and a spring to the conventional one-way gear device, and is easy to assemble. It has the following advantages and is suitable for implementation in a printing machine having the configuration shown in the drawings.

[Brief explanation of drawings]

Fig. 1 is a plan view showing the state in which the double one-way gear device for feeding the printing ribbon according to the present invention is implemented in a printing machine, Fig. 2 is a front cross-sectional view of the main part, and Fig. 3 is a forward movement of the present invention. FIG. 4 is a plan view illustrating the operating state at the same time, FIG. 4 is a plan view during double movement, FIG. 6 and 7 are enlarged front views illustrating the engaged and disengaged states of the clutch of the one-way gear device. 10...Rotating gear, 11...Mounting member, 15,
18... Drive gear and interlocking gear constituting the clutch, 17... Driven cylinder, 20... Rack, 21...
...Feed cylinder, 22...Feed gear, 23...Intermediate gear, 24...Spring, 30...Printer stand,
34... Ribbon cassette, 35... Ribbon feed roller, 40... Machine frame, PR... Printing ribbon.

Claims (1)

[Scope of utility model registration request] A printer stand is attached to a machine frame provided with a rack so as to be movable back and forth, and a driven cylinder that rotates a printing ribbon feed roller on the ribbon cassette side mounted on this printer stand is connected to the printer together with a rotating gear that meshes with the rack. While it is rotatably attached to the stand side,
Inside the driven cylinder, the above-mentioned rotating gear easily meshes with the forward movement of the printer stand, and when it rotates in the forward direction, it meshes and rotates the driven cylinder in conjunction, causing the printing ribbon feeding roller to rotate. In addition, when the rotary gear is easily engaged and reversely rotated due to the back movement of the printer stand, the clutch mechanism is configured so that the gear is disengaged and the driven cylinder does not feed and rotate the printing ribbon feeding roller. In the one-way gear device for feeding a printing ribbon, the feeding cylinder equipped with a feeding gear is rotatably fitted into the driven cylinder, and the above-mentioned rack is mounted on the printer stand side. An intermediate gear is installed on the circumferential surface of the driven cylinder, one end of which is fixed to the feed cylinder. The other end of the spring is wound in a coil shape so that when the sending cylinder rotates in the interlocking rotation direction of the driven cylinder, the driven cylinder is tightened and rotated together. Double one-way gear device for ribbon feeding.