JPH0257773B2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field This invention relates to printing devices such as typewriters and printers, especially those that use a type wheel formed into a cassette. Regarding the type wheel mounting structure to be attached.

Prior Art Printing devices such as typewriters and printers that use type wheels in the form of cassettes transmit the rotation of a selection motor to a petal-shaped type wheel with type arranged around its outer periphery via its rotating shaft, thereby producing the desired output. Select type and print sequentially on the paper on the platen. Therefore, when the cassetted type wheel is attached to the rotating shaft, in particular, in order to facilitate the selection of the desired type,
It is desirable to always position and attach it at a constant position, that is, the home position, with respect to the rotation axis.

Conventionally, this type of type wheel mounting structure was
For example, there are those shown in FIGS. 1A and 1B.
What is indicated by the reference numeral 10 in the figure is a petal-shaped type wheel, which has type letters 12 arranged in a line around its outer periphery and a through hole 14 in the center. Around the through hole 14,
It has an appropriate number of connecting holes 16. The type wheel 1
0 is stored in the cassette case 18. A base end of a retaining spring 22 is attached to the surface of a top plate 20 of this cassette case 18. The retaining spring has a protrusion 24 at its approximately center and a retaining claw 26 at its tip facing inward. And type wheel 1
0 is stored in the cassette case 18, the protrusion 24 of the holding spring 22 enters the through hole 14 of the type wheel 10 to position the center, and the holding claw 26 enters the connecting hole 16 of the type wheel 10. Type wheel 1 inside cassette case 18
0 is held at a fixed position in advance. The cassette case 18 containing the type wheel 10 is inserted into a cassette holder provided in the carriage of the printing device. On the other hand, the carriage has type wheel 1.
There is a rotating shaft 28 of 0, and a connecting arm 32 having a connecting claw 30 at the tip is attached to the rotating shaft. When the rotating shaft 28 rotated by the selection motor 34 is connected to the type wheel 10, it is controlled so that the connecting claw 30 of the connecting arm 32 corresponds to the connecting hole 16 of the type wheel 10 and stops. . Therefore, after inserting the cassette case 18, the selection motor 34 is moved forward, and the tip of the rotating shaft 28 is inserted into the through hole 14 of the type wheel 10.
Insert the connecting claw 3 of the connecting arm 32 at the same time.
0 into the connecting hole 16 of the type wheel 10, push out the protrusion 24 and the retaining pawl 26 against the retaining spring 22, and rotate the type wheel 10 onto the rotating shaft 28.
Attach it at a fixed position. Therefore, the rotation of the selection motor 34 can be transmitted to the type wheel 10 via the connecting arm 32, and desired characters can be selected and printed.

However, according to this conventional type wheel mounting structure, it is necessary to set the connecting arm 32 at a fixed position when mounting the type wheel, which requires a separate circuit to hold the rotating shaft 28 at a fixed rotational position. However, it had the disadvantage of increasing costs.

Purpose Therefore, the present invention eliminates the need to determine the rotational position of the rotary shaft when connecting the above-mentioned rotary shaft and the type wheel, and makes it possible to easily connect the type wheel regardless of the rotational position of the rotary shaft. The purpose of the present invention is to provide a mounting structure that allows for cost reduction.

Configuration This invention will be described in detail below according to embodiments of the invention shown in the drawings.

FIG. 2 shows a type wheel mounting structure according to the present invention. The type wheel indicated by reference numeral 50 in the figure is
It is housed in a cassette case 51 and is not shown. It is mounted on the carriage via retaining means. On the other hand, there is a selection motor on the carriage, and the rotation of the selection motor is transmitted to the type wheel 50 via its rotating shaft 52. The selection motor is moved by an appropriate means in the direction of the arrow in the figure, and is configured so that its rotating shaft 52 can be inserted into the center through hole 54 of the type wheel 50 in the cassette case 51 attached to the carriage. Ru.
As a result, the type wheel 50 is rotated by the selection motor to select a desired type. Then, as described above, the back surface of the selected type is struck with the type hammer 56, the type is struck against the platen 58, and printing is sequentially performed on the paper on the platen.

The type wheel 50 used in the printing device shown in FIG. 2 is as shown in FIGS. 3 and 4. A tube metal 60 is fitted into the center through hole 54 of the type wheel 50 . Furthermore, this type wheel 50 has a central boss portion 62,
Letters 66 are arranged in a line at the tips of a plurality of spokes 64 extending radially from the boss. However, this type wheel 50 further has an annular plate 70 concentrically attached to its back side, that is, to the selection motor side of the central boss portion 62. The annular plate has a wheel setter 7, which will be described later.
Three engaging protrusions 76 having slightly different sizes are provided at positions corresponding to the two engaging windows 74, respectively.
The engaging protrusions are provided at appropriate fixed positions at different distances from the center of the annular plate 70. Further, a mounting hole is formed in the annular plate 70, and a convex portion 77 provided on the central boss portion 62 of the type wheel 50 is fitted into the mounting hole, so that the engaging protrusion 76 is positioned at a certain position relative to the type wheel 50. The annular plate 70 is attached to the type wheel 50 by positioning the annular plate 70 at the position shown in FIG. On the other hand, a stop plate 78 is concentrically attached to the front side of the type wheel 50. As shown in FIG. 4, three arcuate windows 80 are formed along the circumference of the stop plate. The arcuate windows are opened leaving stopper portions 82 at adjacent locations.

Such a type wheel 50 is housed in a cassette case 51 as shown in FIGS. 2 and 5. The cassette case has a bottom plate 84, a rib 86 rising from the bottom plate and defining a circular wheel storage space, and a top plate 88 covering the front half of the wheel storage space. Its bottom plate 84
has an annular rib 90 on which the type wheel 50 rides. The top plate 88 has a window 9 in an inverted U shape as shown in the figure.
2 is opened, and a tongue-shaped elastic body 94 is formed. The tip of this elastic body is located at the center of the wheel storage space. A substantially conical central protrusion 96 is formed on the inner surface of the tip. A circular protrusion 98 is provided concentrically around this protrusion. Furthermore, an engaging protrusion 100 is provided on the inner surface of the elastic body 94 at a position corresponding to the arcuate window 80 of the stop plate 78 near the projection 96.

As shown in FIG. 2, the type wheel 50 housed in such a cassette case 51 has a center protrusion 9 of an elastic body 94 in its center through hole 54.
6 is inserted. The circular protrusion 98 of the elastic body 94 elastically presses the end face of the cylindrical metal 60 in the center through hole 54 of the type wheel 50, thereby causing the type wheel 50 to rest on the annular rib 90 of the cassette case 51. Being pressed against me. At this time, the second
As shown in the figure and FIG. In this way, the type wheel 50 is centered and positioned within the cassette case 51 and held in place without damage.

Therefore, as shown in FIG. 2, the type wheel 50 housed in such a cassette case 51 is attached to the above-mentioned carriage via the holding means so that its center through hole 54 butts against the rotating shaft 52. It will be done. At the tip of the rotating shaft 52,
A large diameter shaft portion 102 is provided integrally with this. Further, a fixed cylinder 104 is attached to the rotating shaft 52 so as to straddle the rotating shaft 52 and the large diameter shaft portion 102 . An annular wheel setter 72 is attached to the fixed cylinder 104 on the type wheel 50 side perpendicularly to the rotating shaft 52. As will be described later, the wheel setter has an annular plate 7 of the type wheel 50 at a certain position.
Engagement windows 74 are opened to which the three engagement protrusions 76 at 0 engage, respectively. Further, as shown in FIG. 2, grooves 106 are cut in the large diameter shaft portion 102 of the rotating shaft 52 in the axial direction on the upper and lower sides thereof. A hole 108 for receiving the protrusion 96 of the elastic body 94 is formed at the tip of the large-diameter shaft portion 102 in which the groove has been cut. Further, detent springs 110 are disposed within the grooves 106 of the large diameter shaft portion 102, respectively. The tip of the detent spring on the type wheel 50 side is bent into a mountain shape. The base end of the detent spring 110 is bent into an L shape, passes through the large diameter shaft portion 102, and is fixed by appropriate means.

Therefore, when attaching the cassetted type wheel 50 to such a rotating shaft 52, first, the rotating shaft 52 is advanced toward the type wheel 50 by an appropriate means, and as shown in FIG. The radial shaft portion 102 is inserted into the central through hole 54 of the type wheel 50 . As a result, the large-diameter shaft portion 102 pushes the center protrusion 96 against the elastic force of the elastic body 94 of the cassette case 51, and pushes the circular protrusion 98 onto the platen 5 of the barrel 60.
It enters into the center through hole 54 while separating from the end face on the 8 side. The detent spring 110 enters the cylindrical metal 60 while sliding with its chevron-shaped portion sunk. At the same time, when the rotary shaft 52 moves forward, the wheel setter 72 moves the type wheel 50
The type wheel 50 is pushed against the engaging protrusion 76 of the annular plate 70, and the entire type wheel 50 moves toward the platen 58. The rotating shaft 52 is
The type wheel 50 is moved forward until its stop plate 78 touches the upper side of the top plate 88 of the cassette case 51, and is stopped there. At this time, the chevron-shaped portion of the detent spring 110 is moved from the barrel metal 60 to the platen 58 side. In the detent spring 110 with this indexed position, the inclined surface on the side of the wheel setter 72 in the chevron-shaped part is
0 on the platen 58 side elastically,
As a result, the type wheel 50 is pressed against the wheel setter 72 via the engagement protrusion 76 of the annular plate 70 and held.

Next, from the type wheel holding state shown in FIG. 6, the selection motor is started to rotate the wheel setter 72 via the rotating shaft 52, and the type wheel 50 is engaged as shown in FIG. The mating protrusions 76 are connected to the engagement windows 74 of the wheel setter 72, respectively.
Type wheel 50 is depressed into and engaged with the type wheel 50.
is set at that fixed position. However, in this case, and particularly with this invention, the type wheel 50 shown in FIG.
In the holding state, the engaging protrusion 10 of the elastic body 94
0 and the lower arcuate window 80 in the stop plate 78 of the type wheel 50 are in final engagement. Therefore, even if the rotating shaft 52 is rotated in this state,
The type wheel 50 rotates until the engaging convex portion 100 of the elastic body 94 comes into contact with the stopper portion 82 of the arcuate window 80, but beyond that point, the movement of the type wheel 50 is restricted by the stopper portion 82 and rotates. It never moves. That is, rotation of the type wheel 50 beyond a certain level is prevented. However, if the rotary shaft 52 is further rotated in this state and only the wheel setter 72 is rotated with respect to the type wheel 50 while the type wheel 50 remains as it is, the type wheel 50 will eventually move due to the biasing force of the detent spring 110 and become engaged. The mating protrusion 76 is engaged with the engagement window 74, and the seventh
As shown in the figure, the annular plate 70 of the type wheel 50 is brought into contact with the wheel setter 72 and stopped. As a result, the engaging convex portion 100 of the elastic body 94 is disengaged from the arcuate window 80 of the type wheel 50, and the above-described state of preventing rotation of the type wheel 50 is released.
On the other hand, since the detent spring 110 continues to press the type wheel 50 against the wheel setter 72 by the inclined surface of the chevron-shaped portion on the wheel setter 72 side, the type wheel 50
is still rotatably held in its fixed position. Moreover, since the type wheel is mounted face-to-face with the wheel setter 72 which is perpendicular to the rotating shaft 52, the type wheel is set and mounted at a position perpendicular to the rotating shaft 52.

After the type wheel 50 is thus positioned and attached at a fixed position and perpendicular to the rotating shaft 52, the type wheel 50 is rotated from that fixed position to select the desired type 66 and sequentially print it on the paper on the platen 58. I'm going to go.

In this invention, in the above-described embodiment, when positioning the type wheel 50 at a certain position, a stop plate 78 is separately attached to the type wheel, and the arcuate window 80 with which the engaging protrusion 100 engages is opened. .
However, it is also possible, for example, to form the arcuate window in the type wheel itself. Therefore, in this invention, if the rotation of the type wheel can be restricted,
This means that it is sufficient to form at least an arcuate window on the same circumference around the center of the type wheel, with which the engaging protrusion engages. In the embodiment described above, three arcuate windows 80 are provided, and three stoppers 82 are provided between the arcuate windows, but they are located on the same circumference around the center of the type wheel to prevent the rotation thereof. The number of arcuate windows and their stoppers is not limited as long as they can be controlled.

Furthermore, in the embodiment described above, the type wheel 50
As means for positioning the wheel setter 72 at a certain position, an engagement window 74 is provided on the wheel setter 72, and an engagement protrusion 76 is provided on the annular plate 70. However, for example, on the contrary, the wheel setter 72 may be provided with an engagement protrusion, and the corresponding annular plate may be provided with an engagement window.

Although the above-described embodiment uses the type wheel 50 in which the circular protrusion 98 is provided concentrically around the center protrusion 96, the type wheel 50 is not limited to the type wheel having this circular protrusion. Further, although the elastic body 94 provided on the cassette case 51 is formed integrally with the cassette case, it goes without saying that a separate elastic body may be attached to the cassette case instead of this.

Effects Therefore, according to the present invention, when the type wheel is connected to its rotating shaft, the rotation of the type wheel is reliably prevented by the engaging convex portion of the elastic body.
Since the type wheel is positioned on the rotating shaft at a fixed position by simply rotating the rotating shaft appropriately, the operator, for example, does not have to manually position the rotating shaft at a fixed rotational position each time as in the conventional method. , the type wheel can be attached with an extremely simple operation, and there is no need to provide a separate circuit to hold the rotary shaft at a constant rotational position, so overall costs can be reduced. .

[Brief explanation of drawings]

FIG. 1A is a perspective view showing a type wheel housed in a conventional cassette case. Figure 1B
1A is a sectional view of a conventional type wheel mounting structure for attaching the cassetted type wheel shown in FIG. 1A to its rotating shaft; FIG. FIG. 2 shows an embodiment of the type wheel mounting structure of the present invention, and in particular is a sectional view of the type wheel being held on the carriage. FIG. 3 shows an example of a type wheel applied to the present invention, and is a perspective view showing in particular the back side of the type wheel. FIG. 4 is a rear view showing the front side of the type wheel similar to FIG. 3; FIG. 5 is a front view showing a cassette case housing a type wheel according to the present invention. FIG. 6 is a partial sectional view showing one stage of the mounting operation of the type wheel mounting structure of the present invention, particularly before the type wheel is rotated to determine its fixed position. FIG. 7 is a sectional view showing a state in which the type wheel has been set at a fixed position from the state shown in FIG. 6 and its attachment has been completed. 50... Type wheel, 51... Cassette case, 52... Rotating shaft, 72... Wheel setter,
74... Engagement window of wheel setter, 76... Engagement protrusion of annular plate, 78... Stop plate, 80... Arc window of stop plate, 94... Elastic body, 100... Engagement protrusion of elastic body Department.

Claims (1)

[Claims] 1. Insert the type wheel into the cassette case,
The elastic body of the cassette case is engaged with the center of the type wheel to elastically hold the type wheel, and then the cassette case is attached to the main body of the printing device, and the rotation axis provided in the main body of the printing device is connected to the center of the type wheel. engages the center of the type wheel, moves the elastic body to release the elastic holding of the type wheel, rotates the rotating shaft, and rotates the type wheel together with a wheel setter to select a desired type; In a printing device that sequentially prints on sheets of paper on a platen using the selected type, the type wheel and the cassette case are provided with an engaging convex portion on one side, and the other is engaged with the engaging convex portion to maintain a constant position of the type wheel. An arcuate window is provided to prevent rotation above a certain level, and an engaging protrusion is provided on one side of the type wheel and the wheel setter, and the other side is provided with an engaging protrusion to further prevent the type wheel from rotating beyond a certain level. An engagement window is provided with which the engagement protrusion engages when the wheel setter is rotated by rotating the shaft, and when the rotating shaft is engaged with the center of the type wheel, the engagement window passes through the center of the type wheel and the type character is The wheel is biased toward the wheel setter side, and when the engagement protrusion engages with the engagement window based on the biasing force, the type wheel is moved toward the wheel setter side and the engagement protrusion and the circular arc are moved. A type wheel mounting structure comprising a spring disposed on the rotating shaft for disengaging from the window.