JPS6183085A - Ribbon lift and correction tape lift mechanism of typewriter - Google Patents

Abstract

PURPOSE:To make it possible to simplify a structure, by performing the lift operation of a ribbon without returning said ribbon to a home position by rotating cam shaft by a predetermined angle at every printing of one character while performing the lift operation of a correction tape by the reversal of said cam shaft. CONSTITUTION:When a cam shaft 11 is rotated by a stepping motor and a ribbon lift cam 10 is rotated by 120 deg. from a home position HP, a cam follower 14 is contacted with either one of cam surfaces 12a, 12b, 12c and a ribbon lift arm 15 is revolved around a shaft 17 while a ribbon guide 18 is raised by a predetermined amount to perform the lifting of the ribbon. When a correction tape is lifted, the cam shaft 11 is reversely rotated to an R-direction and a cam follower 23 is pushed up by a cam surface 21 and a tape lift arm 23 is driven to perform the lifting of the correction tape. That is, the cam 10 is rotated by 120 deg. from HP to a P-direction at every printing of one character to perform the lifting of the ribbon and, at this time, the cam follower 22 is not positioned on the cam surface of the cam 20 and the correction tape is not lifted.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to improvements in the printing ribbon lift and correction tape lift mechanisms in typewriters, particularly electronic typewriters.

Conventional technology and problems In general, typewriters use cams to move the ribbon upward and downward.
Step lift and correction tape lift mechanisms are known.

Conventionally, in this type of mechanism, when moving the upper and lower ribbon lift cams, the ribbon lift cams rotate in the forward and reverse directions from the home position. That is, when one lift is completed, the camshaft reverses and temporarily returns to the home position, and then rotates in the same direction as the reverse to perform the next lift. However, this conventional technique has the disadvantage that the printing speed is slow because the cam returns to the home position every time the ribbon is lifted.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a typewriter ribbon lift and correction tape lift mechanism that overcomes the drawbacks of the prior art as described above.

Means for Solving the Interval Vertex In order to solve the above-mentioned drawbacks of the prior art, the present invention has a camshaft rotated by a predetermined angle every time one character is printed to lift the ribbon without returning to the home position. The lift can be performed by reversing the camshaft.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

Referring to FIG. 1, a typewriter embodying the present invention
A ribbon lift and correction tape lift mechanism is shown, which includes a ribbon lift cam 10 attached to a camshaft 11, which is driven by a stepping motor (not shown). be done.

A plurality of lift cam surfaces 12 are formed on the ribbon lift cam. In the illustrated embodiment, these cam surfaces are lift cam surfaces 12a arranged on the end surface of the lift cam so as to divide the periphery of the cam into three equal parts.

12b, 12? It consists of Non-cam surfaces 1:EZ, 1.1, and 13C extend continuously between these cam surfaces. Since the lift cam surfaces are arranged to be divided into three equal parts, the angle between these cam surfaces is 120 DEG -the cam follower 14 contacts the lift cam surfaces and the non-cam surfaces.

This cam follower is provided at one end of the ribbon lift arm 15. The cam follower, in one example, comprises a bin slidably supported on a ribbon lift arm, as shown in FIG. This pin is compression spring 1
It is pressed by 6.

The lift arm is rotatably supported by a typewriter body (not shown) by known support means. This support means consists of a shaft 17 rotatably attached to the body of the typewriter and an eccentric body 17α formed in the shaft and inserted into a hole provided in the lift arm.

A ribbon guide 18 is provided at the other end of the lift arm 15, and this ribbon guide supports a ribbon (not shown).

In FIG. 1, reference numeral 19 indicates a normal ribbon feed cam.

A tape lift cam 20 for correction (correction +y) tape lift is also attached to the camshaft 11.

One tape lift cam surface 21 and a non-cam surface 21 are formed on the end surface of this tape lift cam. A cam follower 22 is arranged so as to be in contact with the cam surface and the non-cam surface, and this cam follower is attached to one end of the tape lift arm 23. This cam follower can be of the same configuration as the cam follower of the ribbon lift arm described above.

The tape lift arm 23 is rotatably supported by a support shaft 24 on the body of the typewriter. Although not shown, a tape guide is provided at the other end of the tape lift arm, and this tape guide supports the correction tape.

Therefore, the ribbon lift cam 10 and the tape lift cam 2
0 is attached to the camshaft 11 in the following relationship. That is, when the cam follower 14 of the ribbon lift arm 15 is in contact with any of the lift cam surfaces 12α, 12b, and 12C, the cam follower 22 of the tape lift arm 23 is in contact with the non-cam surface 21' of the tape lift cam 20.
However, when the cam follower 22 of the tape lift arm 23 is in contact with the tape lift cam surface 21, the cam follower 14 of the ribbon lift arm 14 touches any of the non-cam surfaces 13α, 13b, and 13C of the ribbon lift cam 10. We started coming into contact with each other (・ru.

Further, the phase % L[X of the ribbon lift cam 10, tape lift cam 20, and ribbon feed cam 19 is set as shown in FIG.

The operation of the above mechanism is as follows.

First, the cam shaft 11 is rotated by a stepping motor to move the ribbon lift cam 10 from its home position to the first position.
Rotate 120° in the P direction as shown in the figure. Here, in the home position/fun, the cam follower 14 is on the non-cam surface 13α
, 1:3b.

13C and rotated 120 degrees from this home position.

The cam follower 14 has a cam surface 12a, 1:l.

12C.

As a result, the ribbon lift arm 15 is rotated about the shaft 17 in the direction indicated by the arrow in FIG. 1, thereby raising the ribbon guide 18 by a predetermined amount and lifting the ribbon. In this case, the ribbon lift cam 10 is one part that returns to the home position every time it rotates 120 degrees, and the ribbon lift cam moves 12 degrees from the home position /Y / in the P direction every time one character is printed.
It is positioned at 0° rotation, lifts the ribbon, and waits at that position until the next printing signal is received.

When the ribbon lift cam is in this position, the cam follower 22 is not located on the cam surface 21 of the tape lift cam 20, so the collection tape is lifted (.

Next, when lifting the collection tape, the camshaft 11 is rotated in the R direction, which is opposite to the P direction previously, and thereby the cam follower 22 is pushed up by the cam surface 21 and the tape lift arm 23 is driven. lift the collection tape. At this point, the cam follower 14 of the ribbon lift arm 15 is located at one of the non-cam surfaces L30L, 13h, and L3C of the ribbon lift cam, and the ribbon lift is not performed. Note that the cam shaft is at the home position during conch shore. By stopping at , it is possible to prevent characters from overlapping in the next printing.

Effects of the Invention According to the present invention, the camshaft rotates by a predetermined angle every time one character is printed, and the condensation only needs to be rotated in the opposite direction from that rotation. Moreover, since the ribbon lift cam always returns to the home position, there are practical benefits such as the operator being able to easily confirm printed characters even during high-speed printing.

[Brief explanation of the drawing]

Fig. 1 is a schematic perspective view showing the mechanism of the present invention, Fig. 2 is a cam diagram showing the phase relationship among the ribbon lift cam, tape lift cam, and ribbon feed cam, and Fig. 3 shows the structure of the cam follower. It is a partially sectional view. 10.Parimbo lift cam 11..Cam shaft 12α
, 12b, L2C... Lift cam surface 15... Ribbon lift door 4 20... Tape lift cam 21... Tape lift cam surface

Claims (1)

[Claims] A ribbon lift cam having a plurality of lift cam surfaces and a non-cam surface that continuously connects these cam surfaces, and a cam follower that contacts the lift cam surface and the non-cam surface at one end and supports a ribbon at the other end. A ribbon lift arm, a tape lift cam for a correction tape lift having one tape lift cam surface and a non-cam surface, and a cam follower at one end that contacts the cam surface and the non-cam surface of the tape lift cam. a tape lift arm that supports the tape at the other end, and the ribbon lift cam and the tape lift cam are such that when the cam follower of the ribbon lift arm is in contact with the lift cam surface, the cam follower of the tape lift arm is in contact with the tape lift cam. is arranged in such a relationship that when the cam follower of the tape lift arm is in contact with the tape lift cam surface, the cam follower of the ribbon lift arm is in contact with the non-cam surface of the ribbon lift cam. A typewriter ribbon lift and correction tape lift mechanism characterized by: