JPH0243728Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a type wheel type printing device in which a plurality of type wheels are provided in parallel on a reciprocating rotating shaft.

(Prior art) This type of type wheel printing device has a plurality of type wheels having type on the outer circumferential surface and ratchets on the side surfaces, which are installed in parallel on a rotating shaft that reciprocates once in one printing cycle. When the shaft rotates in the forward direction, the selection lever is locked to the ratchet, and each printing wheel is selectively stopped from rotating for printing.After printing, all the printing wheels are reset to the initial position on the rotating shaft. It's getting old. Each type wheel and rotating shaft communicate with each other via a kind of friction slip mechanism, for example, one end of a spring member (friction spring) is attached to one of the type ring and the rotating shaft in a relatively unrotatable manner, and the other end A structure is adopted in which the printing type is frictionally attached to the other of the type wheel and the rotating shaft (for example, Japanese Patent Application Laid-Open Nos. 14415/1982 and 150512/1982). Furthermore, as a spring member,
an outer ring portion that holds the typeface between the typeface and the type ring edge;
There is a type ring spring made up of a protrusion and an inner ring having an arcuate spring portion, which is integrally connected to the side surface of the type ring (Japanese Utility Model Publication No. 36465/1983).

(Problems to be Solved by the Invention) In this known structure, the positions or clearances in the thrust direction of the type wheels, which should actually rotate independently, must be secured by separate members.
The independent rotation of each type wheel is unstable, and there remains a problem in operational stability. However, if the positioning of the type wheels in the thrust direction is performed using a separate member, a disadvantage arises in that the parallel pitch of the type wheels increases.

Therefore, an object of the present invention is to improve the operational stability by ensuring the positioning of the type wheel in the thrust direction without using a separate member.

(Means for Solving the Problem) Based on this purpose, in the present invention, a spring arm is integrally formed on each type wheel, and the tip of the spring arm is engaged with a notch in the thrust direction of the rotating shaft. When the type wheel is interlocked with the rotating shaft and the type selecting means is actuated by a selection signal and engages with the ratchet of the type wheel to stop the type wheel, the spring arm escapes from the notch and moves around the outer periphery of the rotating shaft. The surface is slidable, and a projection is provided at the tip of the spring arm, which is engaged with an annular positioning groove provided on the rotating shaft to position the type wheel in the thrust direction.

(Function) This structure ensures the clearance or positioning of each type wheel in the thrust direction without requiring any separate members, and achieves stable independent rotation and miniaturization of each type wheel. .

(Example) In FIGS. 1 to 3, the rotating shaft 10 is rotated reciprocally in one printing cycle via a drive device (not shown), and has a notch 11 formed in the thrust direction. At the same time, an annular positioning groove 12 deeper than the notch 11 is formed at a predetermined interval.
is drilled there. On this rotating shaft 10, a number of type wheels 20 corresponding to the number of digits to be printed are rotatably arranged in parallel. The type wheel 20 has type characters 21 on its outer peripheral surface,
It has a ratchet 22 on the side. Furthermore, a cut groove 24 is cut from the center shaft hole 23 of the type wheel 20, and a spring arm 25 is provided integrally with the type wheel at the center of the cut groove 24.
The tip of the spring arm 25 is engaged with the notch 11 of the rotating shaft 10. A protrusion 26 is provided at the tip of the spring arm 25 and engages with the positioning groove 12 of the rotating shaft 10. The tip of the spring arm 25 is formed into a notch 11 by the deflection of the spring arm.
However, the protrusion 26 can be removed from the positioning groove 1.
2, and this positions the type wheel in the thrust direction. Cut groove 2
On the inner surface of 4, tensioning 27a and 27b protrude oppositely from each other with the spring arm 25 in between.
The displacement in the circumferential direction that occurs when escaping is regulated within a certain range.

A tip 41 of a selection lever 40, which is a type selection means switched by an electromagnetic device 30, is removable from the ratchet 22 of each type wheel 20. The electromagnet device 30 is composed of yokes 32 and 33 magnetized by a permanent magnet 31, coils 34 and 35 wound around the yokes 32 and 33, and a yoke 36 disposed between the tips of the yokes 32 and 33. ing. Note that the yoke 36 may be made of a permanent magnet. The selection lever 40 is swingable by a shaft 43, and the other end 42 is inserted into the gap between the yoke 32 and the yoke 36 or the gap between the yoke 33 and the yoke 36. The selection lever 40 is moved by a biasing spring 44 in the direction in which its tip 41 engages with the ratchet 22 (first direction).
(counterclockwise in the figure), but this urging force is slight and weaker than the magnetic attraction force with the yoke 32 or 33. Further, the selection lever 40 can be instantly switched between two stable positions by a biasing spring 44, and the other end 42 is connected to the yoke 3.
When the yoke 3 is located at the center of the gap between the yoke 36 and the yoke 36, it is defined as a neutral position.
It is instantaneously displaced to the 2 or 33 side, or to the yoke 36 side, and is magnetically attracted to a stable position.

Each type wheel 20 and rotating shaft 10 are connected to a spring arm 25
are connected via. R is an ink roller, and P is a recording paper.

Next, to explain the operation, in the initial state shown in FIG.
When rotated, the type wheel 20 also rotates its spring arm 25.
are engaged with the notch portion 11, so they are driven to rotate in the same direction. During the forward rotation of the rotary shaft 10, when a pulse is applied to the coil 34 and the magnetic flux of the permanent magnet 31 is canceled, the rotating shaft 10 rotates counterclockwise by the biasing force of the biasing spring 44 as shown in the second figure, and the selection is made. Lever 4
0 so that the other end 42 comes into contact with the yoke 36. As a result, the tip of the selection lever 40 engages with the ratchet 22, thereby stopping the driven rotation of the type wheel 20 and selecting a type. As the rotating shaft 10 continues to rotate, the spring arm 25 escapes from the notch 11 due to its deflection and slides on the circumferential surface of the rotating shaft 10. At this time, displacement of the spring arm 25 in the circumferential direction is regulated by the degree setting 27a. The printing operation is carried out when the type on the digit type wheel is selected and the rotary shaft 10 reaches the position shown in FIG.

After printing is completed, the rotating shaft 10 rotates in the opposite direction (counterclockwise). The spring arm 25 continues to slide on the circumferential surface of the rotating shaft, but at this time, its displacement in the circumferential direction is regulated by the degree setting 27b. When the notch 11 of the rotary shaft 10 faces the spring arm 25 during the backward rotation, the tip of the spring arm engages with the notch 11 again (the state shown in the second figure), and as a result, the type wheel 20 again moves to the rotary shaft 10. Rotates driven by. Due to this driven rotation, the tip 41 of the selection lever 40 is pushed up by the ratchet 22 and rotates clockwise around the shaft 43, so that the other end 42 is located at the neutral center of the gap between the yoke 32 and the yoke 36. At that moment, the biasing spring 44 moves the first
As shown in the figure, it switches to a position where it contacts the yoke 32 and is magnetically attracted. By rotating the rotary shaft 10 counterclockwise back to its original position, all the type wheels 20 are returned to their initial positions in FIG. Throughout all of this movement, the projection 26 is located within the positioning groove 12, so there is no displacement of the type wheel 20 in the thrust direction.

(Effects of the invention) According to the structure of the invention, the clearance or positioning of the type wheels in the thrust direction can be ensured by the protrusion at the tip of the spring arm that is integrally formed with the type wheel, and the type wheels can be independently Rotation motion becomes stable. Furthermore, since the tip of the spring arm is in elastic contact with the circumferential surface of the rotating shaft having a constant circumference, the frictional load is constant and the sliding movement is not strained. In addition, miniaturization, especially the parallel pitch of type wheels, can be made smaller.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIGS. 1 to 3 are cross-sectional side views explaining the operation, FIG. 4 is a partially enlarged cross-sectional side view, and FIG. 5 is a view taken along line V-V in FIG. FIG. 10... Rotating shaft, 11... Notch, 12...
...Positioning groove, 20...Type wheel, 21...Type type,
22... Ratchet, 23... Central shaft hole, 24...
... cut groove, 25 ... spring arm, 26 ... protrusion, 27a, 27b ... degree determination, 40 ... type selection means.

Claims (1)

[Claims for Utility Model Registration] (1) A rotating shaft having a notch formed in the thrust direction on the outer circumferential surface, letters on the outer circumferential portion and a ratchet on the side surface, which are rotatably arranged side by side on the rotating shaft. a spring arm that engages with the notch and rotates the type wheel in conjunction with the rotation of the rotating shaft or slides on the outer peripheral surface of the rotating shaft; and a spring arm that is activated by a selection signal. the spring arm is formed integrally with the type wheel and has a protrusion at its distal end, the spring arm being engaged with the ratchet to selectively stop the type wheel; A type wheel type printing device characterized in that an annular positioning groove for holding the position of the type wheel in the thrust direction is formed on the outer circumferential surface of the rotating shaft to be deeper than the depth of the notch. (2) In claim 1 of the utility model registration, the spring arm is formed by a notch groove cut from the center shaft hole of the type wheel, and the spring arm is sandwiched on the inner surface of the notch groove, and the spring arm is oppositely formed around the spring arm. A type wheel type printing device that is equipped with a degree setting to restrict directional displacement.