JPS6183089A - Ribbon lift mechanism of typewriter - Google Patents

Abstract

PURPOSE:To simplify a mechanism by dispensing with the cam for a wobbler eccentric, by operating the wobbler eccentric for performing a minute amount of lift by using the change in the rotary angle of a lift cam being a main lift mechanism as a signal. CONSTITUTION:When a cam shaft 11 is driven by a stepping motor and a ribbon lift cam 10 is revolved, a ribbon is lifted at a fundamental truck position. When the ribbon lift cam 10 is rotated by 240 deg., the projection pat 50 of the cam 10 pushes a wobbler lever 51 which is, in turn, revolved around a shaft 52 to push a wobbler eccentric 16. At this time, the pawl 51a on the upper surface of the lever 51 is engaged with the groove 55a of a holding member 55 and the ribbon is lifted at a shifted truck position. When the cam 10 is further rotated, the pawl 51a is engaged with the separated groove 55b of the holding member 55 and the ribbon is lifted at a further shifted position. When the cam 10 further rotates and there is no groove corresponding to the pawl 51a, the engagement of the lever 51 and the wobbler eccentric 16 is released and the ribbon is returned to a home position.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a ribbon lift mechanism for a typewriter, particularly an electronic daisy-wheel typewriter, and more particularly,
This invention relates to an improvement of a multi-strike ribbon lift (9 stages) mechanism.

(Prior Art and Problems) Generally, in a typewriter, a normal ribbon lift has three ribbon lift stages using a ribbon lift feed wheel and a ribbon lift cam. Therefore, the multi-strike ribbon lift uses a wobbler cam to rotate the wobbler lever and press the wobbler eccentric, which converts the 3 stages of a large ribbon lift truck into 3 smaller stages, for a total of 9 stages of lift. It is carried out.

Conventionally, in this type of ribbon lift mechanism, a three-stage ribbon lift is performed using a plurality of cams arranged on the same axis in an overlapping manner. Therefore, a wheel was required to move the follower (cam follower) into contact with each of these cams, and a wheel was also required to drive the Wopler eccentric. Therefore, the structure is complicated and the cost is high.

SUMMARY OF THE INVENTION An object of the present invention is to provide a ribbon lift mechanism for a typewriter which overcomes the drawbacks of the prior art as described above.

(Means for Solving the Problems) In order to solve the above-mentioned drawbacks of the prior art, the present invention uses a change in the rotation angle of the lift cam as a signal to perform an eccentric operation.

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

In FIG. 1, reference numeral 10 indicates a ribbon lift cam.

This ribbon lift cam lifts the ribbon R shown in FIGS. 4 and 5, and is attached to the cam shaft 11. This camshaft is driven by a stepping motor (not shown).

The cam is formed with a cam surface 2, in contact with which is a follower 13, which is attached to one end of the ribbon lift arm 14. This ribbon lift arm is attached to a typewriter (not shown) by means of a support shaft 15.
is rotatably attached to the main body of the This support shaft has an eccentric shaft 15. A wobbler eccentric (IJ rack 6) is attached to this eccentric shaft.

A tape lift cam 20 and a ribbon feed cam 30 are also attached to the camshaft 11.

A cam surface 21 is formed on the tape lift cam 20 , and a follower 22 is in contact with this cam surface, and this follower is attached to a tape lift arm 23 .

A conventional transmission means 4.0 is connected to the ribbon feed cam 30, and the ribbon is fed through this transmission means.

The ribbon lift during multi-strike consists of a total of 9 stages of lift, including 3 stages at the top, middle, and bottom by the ribbon 1 knot cam, and 3 stages by the wobbler eccentric 1 and □ rick 16 in a small amount. Therefore, the ribbon lift cam is operated repeatedly by the stepping motor in one cycle from 0 → 80° → 0 → 160° → 240° → 0, but the maximum rotation angle changes to 240° and 2509260° with each cycle. (See Figure 3). The phase relationship among the ribbon lift cam, tape lift cam, and ribbon feed cam is set as shown in FIG.

A mini-track driving means is provided which uses changes in the rotational angle of the lift cam as a signal to operate the Wave Sea eccentric and lift the Ribo 7R finer than the amount of lift by the ribbon lift and toke cam. In the illustrated embodiment, this mini-track driving means includes a protrusion 50 provided on one end surface of the ribbon lift cam 10, and a wobbler shear 51 whose one end is connected to the protrusion and the other end is engageable with the wobbler eccentric 16. ing. The middle portion of this wobbler lever is rotatably attached to a shaft 52.

This shaft is supported by the body of the typewriter.

In FIG. 1, reference numeral 53 indicates a tension spring that urges the wobbler lever 51 in a direction in which the other end of the wobbler lever is moved away from the wobbler eccentric 16, and reference numeral 54 indicates a stopper.

A holding member 55 is arranged above the armature lever 51. A claw 51α is provided on the upper surface of the wobbler lever, and this claw is connected to two grooves 55α provided in the holding member.
55b, respectively. The wopler lever 51 is constantly pressed upward by a compression spring 56, and is positioned so that its pawl 51α can be inserted into either of the two grooves 55α and 55b.

Incidentally, reference numeral 60 is a release lever for disengaging the armature lever 51 from engagement with the protrusion 50.

The operation of the above mechanism is as follows.

When the camshaft 11 is driven by the stepping motor and the ribbon lift cam 10 is rotated, the ribbon lift cam moves in three stages as shown in FIG. 4 according to the cam diagram shown in FIG. 3 in one rotation. Perform ribbon lift at positions ■, ■, ■.

When the ribbon lift cam rotates 240 degrees, the protrusion 50 pushes one end of the wobbler lever 51, which rotates about the shaft 52 and the other end pushes the wobbler eccentric 16. At the same time, the claw 51α of the armature lever 51 engages with one of the two grooves 55α of the holding member. At this point, there are six trunk positions ■, ■, which are different from the six truck positions ■, ■, ■ above.

■+17”) Perform IJ bong lift (see Figure 5).

Furthermore, when the ribbon lift cam rotates 250 degrees, the claw 51α of the wopler lever engages with another groove 55h of the holding member, and in this case, the ribbon is moved to six track positions different from the track positions of ■ to ■ above. ■、■.

■It will be lifted to. When the ribbon lift cam rotates 260 degrees, there is no groove in the holding member at the position corresponding to the claw 51α of the Wobbler lever, and therefore the Wobbler lever 51 and the Wobbler eccentric 16 are disengaged, and the Wobbler eccentric returns to the home position. to return to.

In case of single strike ribbon, release lever 60
Remove the armature lever 51 from the protrusion 50 by
Therefore, the Wopler eccentric 16 is not activated. Therefore, in this case, the ribbon has six track positions ■,
Only the lifts of ■ and ■ are performed.

(Effects of the Invention) According to the present invention, there is a practical advantage that the mechanism is simple because the armature eccentric can be operated without the need for a separate cam.

[Brief explanation of drawings]

A schematic partial cross-sectional view of the main parts, Figure 3 is a cam diagram showing the phase relationship of each cam, Figure 4 is a partial plan view showing the track position in the case of a single strike ribbon, Figure 5 is a multi-strike ribbon. FIG. 3 is a partial plan view showing track positions in the case of a ribbon. 10... Ribbon lift cam 11... Cam shaft] 4.
・・Ribbon lift arm

Claims (1)

[Claims] A ribbon lift cam, a ribbon lift arm driven by the rotation of the ribbon lift cam, a wopler eccentric provided on the ribbon lift arm, and a wopler eccentric that is driven by the rotation of the ribbon lift cam. and a mini-track drive means for actuating a puller eccentric.