JPS635979A - Ribbon feeder for printer - Google Patents

Abstract

PURPOSE:To operate a printing ribbon feeding mechanism and a correction ribbon lifting and feeding mechanism by using the same motor and the same can body, by providing a cam body rotated forward and reversely by a motor with an effective cam part and an ineffective cam part. CONSTITUTION:A cam body 19 rotated with a shaft 20 as a center is provided with a single cam groove 21. The cam groove 21 is in the shape of a circular arc having a fixed radius and having a center at the shaft 20. The cam groove 21 comprises an ineffective cam part 21a the cam curve of which is a horizontal straight line and which substantially does not have a cam action, a lifting effective cam part 21b which is continuous with the ineffective cam part 21a on one side of the part 21a and the cam curve of which linearly rises to one end of the cam groove 21, and a printing ribbon feeding effective cam part 21c which is continuous with the ineffective cam part 21a on the other side of the part 21a and the cam curve of which once rises linearly and then falls from an intermediate point to the other end of the cam groove 21. Accordingly, a motor and the cam body can be used in common for both a printing ribbon feeding mechanism and a correction ribbon lifting and feeding mechanism.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a ribbon feeding device for transporting and lifting a printing ribbon and a collection ribbon in a printing machine such as a typewriter or printer.

"Prior art and its problems" A conventional ribbon feeding device is disclosed in, for example, Japanese Patent Application Laid-Open No. 58-1228.
As disclosed in Japanese Patent No. 88, there is a print ribbon feed mechanism that transports the print ribbon in a print ribbon cassette, and a collect ribbon that raises a lift frame to lift the collect ribbon and at the same time transports the collect ribbon along with the movement. The lift and transfer mechanism was installed on the carrier independently of each other, and each operated separately.
The structure was complicated, the number of parts was large, the carrier was large (and it was heavy, etc.), and other disadvantages.

The present invention aims to eliminate such drawbacks.

[Ten Steps to Solve the Problems] In the present invention, a lever of a print ribbon feed mechanism is engaged with a cam body that is rotated forward and backward by a motor, and
An arm integral with or connected to the lift frame is engaged. The cam body includes a print ribbon feed effective cam part that rotates the lever as the cam body rotates, a lift effective cam part that pushes the arm to raise the lift frame, and a print ribbon feed effective cam part that pushes the arm and raises the lift frame. by”
(2) An ineffective cam part is provided that does not operate the arm when the lever is rotated, and does not rotate the lever when the arm is operated by the effective lift cam part.

"Operation" With this configuration, the print ribbon feed mechanism and the collection ribbon lift/transfer mechanism are operated by the same motor and cam body. In addition, when this cam body rotates the lever of the print ribbon feed mechanism and the print ribbon is being transferred, the arm of the lift frame is not operated by the cam body, so the lift frame does not rise, and therefore the collection ribbon is transferred. Lifts and transfers will not take place. - On the other hand, when the arm of the lift frame is operated by the cam body, the lift frame is raised and the collection ribbon is lifted and transferred, but the lever of the print ribbon feed mechanism is not rotated, so the print No ribbon transfer takes place.

"Example" An example of the present invention will be described below in detail based on the drawings.

As shown in FIG. 1.2, the carrier 1 is slid from side to side along the guide shaft 2 and carrier rail 3 parallel to the platen 4. As shown in FIG. A lift frame 5 is pivotally attached to the carrier 1 at its base end by a pin 6 so as to be vertically movable. As shown in FIG. 3, the lift frame 5 has a lower arm 7 on the lower side of its left side edge, and as shown in FIG. A cam engaging pin 9 is provided protruding from the lower end of the lower arm 7, and a collection ribbon guide 10 is fixed to the tips of the left and right arms 8, respectively. On this lift frame 5, a print ribbon 7th slit 1 is removably mounted, and a spool 13 around which the collect ribbon 12 before use is wound and a spool 14 around which the collect ribbon 12 is wound after use are removably installed. It will be installed. Note that the lower arm 7 may not be integrated with the lift frame 5, but may be connected thereto.

Inside the carrier 1, a reversible motor 15 is attached to a vertical motor mounting plate 16, and the rotation of the motor 15 is transmitted to the transmission gear via a motor gear 17 and a transmission gear 18 meshing with the motor gear 17. The signal is transmitted to a circular cam body 19 that is integral with 18.

The cam body 19 rotates around a shaft 20, and is provided with - number of cam grooves (cam tracks) 21. As shown in FIG. 6, this cam groove 21 has a circular arc shape with a constant radius centered on the shaft 20, and is a horizontal straight line in the cam curve shown in FIG. part 21a, an effective lift cam part 21b whose cam curve rises in a straight line up to one end following an example of the invalid cam part 21a, and a lift effective cam part 21b where the cam curve rises in a straight line following the other side of the invalid cam part 21a. The effective cam portion 21 for feeding the printing ribbon moves upward from the middle to the other end, and then moves downward from the middle to the other end.
It is divided into c. The range (angle) of the ineffective cam portion 21a is slightly larger than the respective ranges of the effective cam portions 21b and 21c on both sides.

The cam engagement pin 9 of the lift frame 5 and the cam engagement pin 24 protruding from the lower end of the lever 23 of the printing ribbon feed mechanism 22 are slidably fitted into the cam groove 21. These are normally located in the positional relationship shown in FIGS. 1 and 6, that is, at both ends of the invalid cam portion 21a. The lever 23 has its middle portion supported by a shaft 24, and a spring 2
5 to rotate counterclockwise in FIG.

Therefore, when the cam body 19 is rotated forward and backward within that range by the motor 15 from the state shown in FIG.
Since the cam engagement pin 9 reciprocates and slides inside, the lift frame 5 is moved up and down, and the collection ribbon 12 is moved up and down accordingly.
is transported in a known manner. At this time, cam engagement pin 2
4 slides within the invalid cam portion 1a, the lever 23 does not rotate and maintains the state shown in FIG. 1.

On the other hand, when the cam body 19 is rotated in the forward and reverse directions by the remoter 15 from the state shown in FIG. Since it slides back and forth, the lever 23 is repeatedly rotated back and forth within a predetermined angular range. At this time,
Since the cam engagement pin 9 slides within the invalid cam portion 1a,
The lift frame 5 maintains the state 6 shown in FIG.

When the lever 23 reciprocates in this manner, the print ribbon in the print ribbon cassette 11 is transferred by the print ribbon feed mechanism 22.

That is, the printing ribbon feed mechanism 22 is attached to a rotating arm 28 rotatably attached to the left corner of the lift frame 5 by a shaft 27, as shown in FIG. engages with an arc-shaped arm 30 of a ratchet lever 29 that is pivotally supported by the rotating arm 28, and the rotation of the lever 23 in the counterclockwise direction in FIG. 4 is transmitted to the ratchet lever 29. . As shown in FIG. 8, the ratchet lever 29 is rotatably supported on the pivot arm 28 by a shaft 32 of a spike gear 31. A ratchet wheel 33 and a gear 34 for transporting the fabric ribbon, which is an integral part of the ratchet wheel 33, are fitted onto the shaft 32 so as to rotate together with the spike gear 31. The ratchet lever 29 is biased to rotate by a spring 35, and its resilient claw portion 36 engages with the ratchet wheel 33. The ratchet wheel 33 is braked by a brake leaf spring 37 that is in pressure contact with the ratchet wheel 33. The spike gear 31 is
When the rotating arm 28 is set to the solid line position in FIG. 5, it bites into the printing ribbon in the printing ribbon cassette 11.

Therefore, when the lever 23 is rotated back and forth as described above,
The ratchet lever 29 is rotated in a reciprocating manner, and its claw portion 3
The ratchet wheel 33 is fed in a fixed direction by the ratchet wheel 6, and the spike gear 31 rotates in conjunction with the ratchet wheel 33 to transport the printing ribbon. At this time, since the rotation of the lever 23 is indirectly transmitted to the ratchet wheel 33 by the ratchet lever 29 that rotates around its axis, the rotation is transmitted more smoothly than when it is directly transmitted. . Furthermore, since this ratchet wheel 33 is braked by a braking leaf spring 37, when attaching and detaching the printing ribbon cassette 11 to and from the lift frame 5, the rotating arm 28 is moved between the solid line position and the chain line position shown in FIG. When rotating, the spike gear 31 will not move inadvertently and the printing ribbon will not be transferred inadvertently.

``Effects of the Invention'' As described above, according to the present invention, the print ribbon feed mechanism and the collection ribbon lift/transfer mechanism can share the motor and cam body, which simplifies the structure and reduces the number of parts. This allows the carrier to be made smaller and lighter.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, the first being a side view and the second being a side view.
The figure is a plan view, Figure 3 is a simplified side view during collect operation, Figure 4 is a simplified side view during print ribbon transfer, Figure 5 is a plan view of the lift frame and print ribbon feed mechanism, and Figure 6 is a cam. FIG. 7 is a cam curve diagram thereof, and FIG. 8 is an exploded perspective view of the printing ribbon feed mechanism. 5...Lift frame, 7...Lower arm, 1
1... Printing ribbon cassette, 12...
Collection ribbon, 15...Motor, 19...
...Cam body, 21...Cam groove, 21a...
...Invalid cam part, 21b... Effective cam part for lift, 21C... Effective cam part for printing ribbon feed, 22... Printing ribbon feed mechanism, 23
······lever.

Claims (1)

[Claims] 1. Load the printing ribbon cassette on the lift frame and attach the collection ribbon. When printing, feed the printing ribbon in the printing ribbon cassette using the printing ribbon feed mechanism. When collecting, raise the lift frame and remove the collection ribbon. In a ribbon feeding device of a printing machine that lifts a printer, a lever of the printing ribbon feed mechanism is engaged with a cam body rotated in forward and reverse directions by a motor, and an arm integrated with or connected to the lift frame is engaged; The cam body has a printing ribbon feeding effective cam part that rotates the lever as the cam body rotates, a lifting effective cam part that pushes the arm to raise the lift frame, and a printing ribbon feeding effective cam part. It is characterized by having an ineffective cam part that does not operate the arm when the lever is rotated, and an ineffective cam part that does not rotate the lever when the arm is operated by the effective lift cam part. Printing machine ribbon feeding device.