JPH0374196B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD OF THE INVENTION This invention relates to an eraser ribbon feeding device for a printing machine.

Technical background of the invention and its problems First, FIG. 1 shows a conventional example. 1 is platen 2
This carrier 1 is equipped with a printing section 5 consisting of a daisy wheel 4 driven by a wheel motor 3 and a printing hammer (not shown) driven by a magnet (not shown). ing. The carrier 1 also has a ribbon support stand 6.
A ribbon cassette 9 containing a printing ribbon 8 is detachably attached to the ribbon support 6, and a spool 1 on which an erasing ribbon 10 is wound is attached to the ribbon support 6 so as to be freely raised and lowered around a pin 7.
1 is rotatably held. There are two spools 11 on the take-up side and the supply side, and a ratchet 1 is a wheel that rotates integrally with the spool 11 on the take-up side.
2 is attached to the ribbon support stand 6.

Next, a gear 15 and a cam 16 that are directly connected to a motor 14 are attached to the carrier 1. Teeth 17 that mesh with the gear 15 are formed on one half of the cam 16, and a groove 18 whose radius from the center of the cam 16 changes is formed on the other half of the cam 16. It is fixed to a support stand 6. Further, an L-shaped lever 20 is held on the ribbon support base 6 so as to be freely rotatable around a pin 21. One end of this lever 20 is elastically engaged with the teeth 13 of the ratchet 12, and the other end is attached to the carrier. It is rotatably held by a support 22 fixed to 1.

Therefore, printing is normally performed with the printing ribbon 8 facing the printing part of the daisy wheel 4 as shown in FIG. Although not shown, the printing ribbon 8 is fed in one direction by a known means such as a ribbon feeding motor or a drive shaft that converts the movement of the carrier 1 into rotational movement. When erasing by printing,
The motor 14 rotates the cam 16 to raise the ribbon support base 6 and cause the erasing ribbon 10 to face the type portion of the daisy wheel 4. At this time, lever 2
0 rotates around the pin 21, the upper end of the lever 20 swings out, rotates the ratchet 12 one pitch, and the erasing ribbon 10 is wound onto the spool 11 on the winding side.

However, in the conventional device shown in FIG. 1, when a plurality of characters are to be erased, the movement of the lever 20 is linked to the vertical movement of the ribbon support 6, so that the ribbon support 6 is moved each time one character is erased. It has to be raised and lowered. Therefore, there are problems in that the operating speed is slow and the noise is large.

Purpose of the Invention The present invention has been made in view of the above points, and is a printing method that can feed the erasing ribbon at high speed without raising and lowering the ribbon support, and can reduce noise when feeding the erasing ribbon. The purpose is to use the erasing ribbon feeding device of the machine.

SUMMARY OF THE INVENTION The present invention provides a carrier with a ribbon support holding a printing ribbon and an erasing ribbon, which is movable up and down.
In a device in which the ribbon support is raised and lowered by a cam provided on the carrier to select the printing ribbon usage position and the erasing ribbon usage position, a claw provided on the cam rotates the cam back and forth within the range of the erasing ribbon usage position. The wheel body is continuously rotated in one direction together with the spool on the take-up side of the erasing ribbon, and when the number of characters to be erased continues, the erasing ribbon is fed quickly without raising and lowering the ribbon support base, and moreover, it is possible to reduce noise. This structure is designed to suppress the occurrence of

Embodiment of the Invention An embodiment of the invention will be described with reference to FIGS. 2 to 6. Components that are the same as those described in FIG. 1 are designated by the same reference numerals, and description thereof will be omitted. A ratchet 12, which is a wheel having a large number of teeth 13 formed on its outer periphery, is rotatably attached to the right side of the ribbon support base 6. Further, a supply spool 11 and a take-up spool 11 that rotate integrally with the ratchet 12 are detachably attached to both sides of the ribbon support 6, and a printing ribbon is attached to both sides of the tip of the ribbon support 6. A guide 23 that defines the path of the erasing ribbon 10 is provided below the eraser ribbon 8 . Also, carrier 1
A gear 1 is directly connected to a motor 14 that rotates in forward and reverse directions.
5 and a cam 24 are provided. This cam 24
has teeth 17 that mesh with gear 15 over about half the circumference.
and a groove 25 that engages with the shaft 19 of the ribbon support base 6. From the center of rotation of the cam 24 to the groove 25
The radius to the center of the groove 25 gradually increases in the order of positions A, B, and C. The radius of groove 25 is equal between positions C and D, and in this range, the ribbon support stand 6 is at the upper stage (erasing ribbon usage position), position B is at the middle stage (printing ribbon usage position), and position A is at the lower stage. (printing stop position). An L-shaped pawl 26 is rotatably attached to the outer periphery of the cam 24 between positions C and D by means of a support shaft 27. This pawl 26 is urged toward the ratchet 12 by a torsion spring 28, and the depth of engagement with the ratchet 12 is determined by a stopper pin 29.

In such a configuration, as shown in FIGS. 2 and 3, the cam 24 supports the shaft 19 with the groove 25 at position B, and fixes the ribbon support 6 in the print ribbon use position. That is, the printing ribbon 8 faces the type portion of the daisy wheel 4. Each time one character is printed, the cam 24 rotates counterclockwise to support the shaft 19 at position A in the groove 25, fixing the ribbon support 6 at the lower printing stop position. That is, the print ribbon 8 is deviated below the type part of the daisy wheel 4, and the printed content can be confirmed in an easy-to-see state. During printing, the cam 2 is moved in the range of positions A and B with respect to the shaft 19 of the ribbon support stand 6.
Rotate 4 back and forth.

When finding and erasing misprints, refer to Figures 2 and 3.
Rotate the cam 24 clockwise from the state shown in the figure, and as shown in FIG.
support. As a result, the ribbon support stand 6 rises to the upper erasing ribbon use position, and the erasing ribbon 10 faces the type portion of the daisy wheel 4. To erase continuously, rotate the cam 24 reciprocatingly in the range of positions C and D with respect to the shaft 19, and when rotating counterclockwise, the ratchet 12 is moved to the spool 1 by the pawl 26.
When rotating clockwise, the pawl 26 deflects the torsion spring 28 and retreats from the ratchet 12. Therefore,
When the ribbon support stand 6 is shifted from the erase ribbon use position to the print ribbon use position, the erase ribbon 1
0 is fed one pitch, and the unused portion faces the printed portion of the daisy wheel 4 in preparation for the next erasing operation.

In this way, when the erasing ribbon 10 is continuously fed, the ribbon support stand 6 can be kept stationary, so there is no noise caused by switching the ribbon support stand 6, and the erasing operation is quick. .

Note that the rotation range of the cam 24 and the length of the groove 25 may be shortened, and the switching position of the ribbon support 6 may be changed within the range of positions B, C, and D of the groove 25.

Effects of the Invention Since the present invention is configured as described above, the ribbon support is selectively positioned by the cam at least at the printing ribbon usage position and the erasing ribbon usage position, but the ribbon support is biased in the erasing ribbon usage position. The erasing ribbon can be fed by rotating the wheel together with the take-up spool using the pawl provided on the cam without having to move the erasing ribbon. This has effects such as being able to suppress the generation of noise at times.

[Brief explanation of drawings]

Fig. 1 is a side view showing a conventional example, Figs. 2 to 6 show an embodiment of the present invention, Fig. 2 is a side view, and Fig. 3 is a partially enlarged view of the ribbon support. Figure 4 is a partially enlarged side view showing the state in which the ribbon support is positioned in the position where the erasing ribbon is used. Figure 5 is a side view showing the cam, pawl, and ratchet. FIG. 6 is a graph showing the relationship between the operation of the cam and the operation of the ribbon support base. 1...Carrier, 2...Platen, . 6... Ribbon support stand, 8... Printing ribbon, 10... Erasing ribbon, 11
...Spool, 12...Ratchet, 13...
Teeth, 14...motor, 24...cam, 26...claw.

Claims (1)

[Claims] 1 The carrier moves back and forth facing the platen,
A ribbon support stand that holds a printing ribbon and an erasing ribbon in two stages, upper and lower, is provided so as to be movable up and down, and the carrier supports the ribbon support stand by positioning it at least in a printing ribbon usage position and an erasure ribbon usage position, and supports the ribbon. A cam with a fixed rotation range that does not raise or lower the support base is connected to a motor so that it can freely rotate back and forth, and has a large number of teeth on the outer periphery and rotates integrally with the spool on the winding side of the erasing ribbon. A wheel is located near the cam and rotatably provided on the ribbon support base, and the cam is provided with a claw that moves the wheel in one direction by rotational movement of the cam in a range of the erasing ribbon use position. An erasing ribbon feeding device for a printing machine, which is characterized by: