JPS5917632Y2 - Small printer type selection mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a small printer, and particularly to a mechanism for selecting desired type in a type wheel selection type printer.

It is an object of the present invention to provide a type selection mechanism that is highly reliable and can operate with extremely low power consumption.

Another object of the present invention is to provide a type selection mechanism that is small, lightweight, and inexpensive.

FIG. 1 is a side sectional view showing a specific example of the present invention, and the present invention will be explained in detail below with reference to FIG.

In FIG. 1, a type wheel shaft 1 has a groove 2 on its outer periphery, and supports a type wheel 4 having type characters 3 on its outer periphery.

Reference numeral 5 denotes a type shaft holder which is rotatably attached to a shaft 6 provided on the side surface of the type wheel 4, and engages with a type ring spring 7 attached to the type wheel 4 so that the claw portion 51 moves into the groove of the type wheel shaft 1. A force in the direction of arrow a is applied so as to engage 2.

Reference numeral 8 denotes a detent spring which engages with a protrusion 9 integrally provided on the type wheel 4 when the type wheel 4 is in a standby state, and determines the standby position of the type wheel 4.

Reference numeral 10 denotes a selection pawl, which controls engagement and disengagement between the pawl portion 51 of the type shaft 5 and the groove portion 2 of the type wheel shaft 1 by engaging with and disengaging from the head 52 of the type shaft 5.

Reference numeral 11 designates a selection claw shaft that supports the selection claw 10, fixes a magnetic disk 12, and rotates in the direction indicated by the arrow.

Reference numeral 13 denotes an iron core, which is inserted into the center of the coiled coil frame 14 so as to be slidable in the directions of arrows g and h, and engages with the end face of the yoke 15 that is covered with dirt through a notch 131 provided at the tail. The head 132 is arranged so as to maintain a slight gap with the side surface of the disk 12 or to slide on the side surface of the disk 12.

Reference numeral 16 denotes a trigger case that holds the coil frame 14 and has a bearing portion that pivotally supports the selection claw 10.

A hammer 17 faces the printing paper 19 at the printing position 18 of the type 3 and performs printing.

An ink roll 20 transfers ink to the type 3 by making rolling contact with the type wheel 4.

The operation of the type selection mechanism constructed as described above will now be described.

In the standby state, the selection pawl 10 is rotated in the direction of arrow e by the spring force of the selection pawl spring 21, and remains stationary with the type ring 4 perpendicular to it.

Further, the head 52 of the expansion shaft 5 and the head 101 of the selection claw 10 are in contact with each other, and the type shaft 5 is rotated in the direction of arrow d.
The engagement between the claw portion 51 and the groove portion 2 of the type wheel shaft 1 is disengaged.

In this state, the detent spring 8 engages with the protrusion 9 of the type wheel 4 and keeps the type wheel 4 stationary, so the type shaft holder 5 disengages the pawl 51 from the groove 2 of the type wheel shaft 1. It is maintained in the same state.

In the type selection process, the type wheel shaft 1 rotates in the direction of arrow C.

Further, the selection pawl shaft 11 is also rotated in the direction indicated by the arrow, and the disc 12 fixed to the selection pawl shaft 11 is rotated together.

The groove 2 corresponding to the type 3 to be printed is the type shaft holder 5.
When the coil 22 is energized and the electromagnetic means described later is operated, the selection pawl 10 is rotated in the direction of arrow f against the spring force of the selection pawl spring 21, and the type shaft 5 is rotated. Disengage the head 52.

The type shaft 5, which is no longer engaged with the selection claw 10, is rotated in the direction of arrow a by the spring force of the type ring spring 7, engages with the groove 2 of the type wheel shaft 1, and rotates in the direction of arrow C. It begins to rotate together with the type wheel spindle 1.

At this time, the type wheel 4, which is integrated with the type shaft holder 5 and shaft 6, also rotates, and the type 3 to be printed comes into contact with the ink roll 20 on the way, and after the ink is transferred, it is rotated to the printing position 18. Ru.

The same operation is performed for each digit, and when all the characters 3 to be printed are aligned in the printing position 18, the hammer 17 is applied to the printing paper 1.
It makes contact with the type 3 across the 9 and performs printing.

This completes the character selection and printing process.

Next, the operation of the electromagnetic means mentioned above will be explained.

When the coil 22 is energized, a magnetic circuit composed of the iron core 13, the yoke 15, and the disk 12 is closed, and the side surface of the disk 12 and the side surface of the head 132 of the iron core 13 are attracted.

Then, the iron core 13 receives the rotational force of the disc 12 rotating in the direction of the arrow A, and is pushed down in the direction of the arrow g, pushing down the protrusion 102 of the selection pawl 10 that is engaged with the iron core 13, so that the selection pawl 10 Rotate in the direction of arrow f.

Here, the head 101 of the selection claw 10 and the head 52 of the type shaft holder 5 are shown.
The engagement is released.

When the coil 22 is de-energized after the engagement is released, the disc 1
2 and the head 132 of the iron core 13 are released and the attachment is separated.

Then, the selection pawl 10 is rotated in the direction of arrow e by the selection pawl spring 21 and returns to the standby state.

After printing is completed, there is a return process in which each selected type wheel 4 is returned to its standby position.

In the return stroke, the type wheel set 1 moves in the direction of arrow C as in the selection stroke.
Rotate once in the direction.

At the same time, the type shaft holder 5, which is engaged with the groove 2 of the type wheel shaft 1, also rotates, and the type wheel 4 also rotates together.

When the type 3 of each type wheel 4 rotates to near the standby state, the head 101 of the selection pawl 10 and the head 52 of the type shaft holder 5 rotate in the direction of arrow e by the selection pawl spring 21 and return.
contact again and the type shaft holder 5 rotates in the direction of arrow d, and the claw portion 5
1 is disengaged from the groove 2 of the type wheel shaft 1.

At this time, the type tent spring 8 engages with the protrusion 9 of the type wheel 4 to keep the type wheel 4 stationary.
It will be held in a disengaged state.

As each type wheel 4 returns, the incorrect selection prevention shaft 23
rotates in the direction of arrow i, and the outer peripheral portion 231 and the selection claw 10
The protrusion 103 is brought into contact with the protrusion 103 .

This prevents the selection pawl 10 from rotating in the direction of arrow f due to external forces such as vibrations and shocks in the standby position, causing the type shaft 5 to engage with the groove 2 of the type wheel shaft 1, thereby preventing erroneous selection. It is.

In addition, the incorrect selection prevention shaft 23 rotates in the direction of arrow i just before the next selection process begins, and a notch 232 is placed opposite the protrusion 103 of the selection claw 10 so as not to interfere with the operation of the selection claw 10. It has become.

This completes the operation of one printing cycle.

In this structure, when no type is selected, only the type wheel shaft 1 rotates and the other parts do not operate.

Also, compared to the conventional method in which the force necessary for the return stroke in the selection stroke is stored in a spring, and the type wheel spindle is reversed by this spring force to perform the return, this structure allows the type wheel spindle to rotate in one direction. Perform selective restoration.

These features make it possible to operate with the lowest power consumption and the average power per printing cycle.

For this reason, it has become possible to provide a compact printer that can be driven by dry batteries or the like, and has a wide range of applications and does not require restrictions such as a power source.

The most significant feature of the electromagnetic clockwise rotation that drives the selection claw 10 is a magnetic circuit composed of a rotating disk 12, and an iron core 13 and a yoke 15 that are adjacent to the disk 12 with a small gap.

Conventionally, in order to make an electromagnet perform a large stroke of work, the attraction distance becomes large, which increases magnetic loss, resulting in poor efficiency.

Furthermore, in order to reduce the loss, if the suction distance is made small and the stroke is amplified to a predetermined value using a lever or the like, the efficiency becomes poor due to the friction loss of the lever, etc.

In the structure according to the present invention, the suction distance between the disk 12, the iron core 13, and the yoke 15 is small and has no relation to the predetermined stroke, and has the role of only generating a suction force, and the predetermined stroke is determined by the driving force of the motor, etc. Since the magnetic force is obtained by rotating the disk 12, the attraction distance is very small, magnetic loss is small, and a large attraction force can be obtained with low power consumption.

Furthermore, the electromagnet can have a very fast response.

Since the efficiency of a motor is usually ten times higher than that of an electromagnet, the overall selection energy can be significantly reduced compared to when using only an electromagnet.

Being able to operate with low power consumption means that the coil windings, etc., need to be small, which not only makes it possible to downsize, but also significantly reduces component costs and assembly costs.

Since the present invention uses an ink roll as an inking means, ink is always transferred to the type 3, and when the rotation of the type wheel 4 is repeated, it is also transferred to the selection claw 10 adjacent to it. Ink will gradually adhere.

If the ink attached to the selection claw 10 flows around the electromagnet mentioned above, it may make the rotation of the selection claw 10 and the selection claw shaft 11 difficult, or it may stick between the attraction surfaces of the disk 12 and the iron core 13 and be attracted. This may lower your ability or cause a number of negative effects.

For this purpose, a flange 104 that is thicker than the thickness near the head 101 is provided in the vicinity where the selection pawl 10 comes out of contact with the type ring 4, and this flange 104 changes the flow of ink and guides the ink in the direction of the projection 103, and the selection pawl axis Prevent ink from flowing into the disk 11, disk 12, etc.

The brim 104 of this selection claw 10 has a shape as shown in a perspective view in FIG.

(The numbers in Figure 2 are the same as in Figure 1.

) By using a selection claw having such a shape, it is possible to reliably prevent ink from flowing into the electromagnetic structure without increasing the number of parts, and to achieve a highly reliable electromagnetic structure.

Next, regarding the structure for preventing erroneous selection, the erroneous selection prevention shaft 23 prevents the selection claw 10 from malfunctioning by abutting the protrusion 103 of the selection claw 10 at the outer peripheral portion 231.

Usually, the outer peripheral surface of a round bar is highly accurate, and the engagement position of the selection claw 10 with the protrusion 103 can be easily achieved.

Furthermore, since the outer circumferential portion 231 engages with the protrusion 103 of the selection claw 10, the rotation angle of the incorrect selection prevention shaft 23 is very rough, and precision of the parts is not required, resulting in an inexpensive structure.

Furthermore, by providing spring properties near the protrusion 103 of the selection claw 10 and engaging the outer circumference 231 of the erroneous selection prevention shaft 23 with some bite, it is possible to prevent the erroneous selection prevention shaft 23 from changing due to variations in component accuracy. There is no gap between the selection claw 10 and the protrusion 103, and a structure that more completely prevents erroneous selection can be achieved, and the precision of the parts can be made rougher and cheaper.

Since the spring portion is integrally provided near the protrusion 103 of the selection pawl 10 as described above, the cost of parts for creating a spring-engaging structure does not increase.

As described above, according to the type selection mechanism according to the present invention, it is possible to provide a compact printer that is highly reliable, can be downsized, and is inexpensive.

Furthermore, a compact printer with extremely low power consumption and a wide range of applications can be provided.

As explained in detail, the effects of this invention are that it is possible to miniaturize, the parts and assembly costs are low, the power consumption is extremely low, and furthermore, it is possible to provide a highly reliable compact printer, which has great effects. It is.

[Brief explanation of drawings]

FIG. 1 is a side sectional view showing a specific example of the present invention, in which 1 is a type wheel shaft supporting a type wheel 4, 5 is a type shaft, 7 is a type ring spring, 8 is a dipunto spring, and 16 is a selection claw 10. , selection claw shaft 11. A trigger case that holds the disc 12, the iron core 13, and the coil 22, 15 is a yoke, 17 is a hammer, 19
is printing paper, 20 is an ink roll, 21 is a selection spring, 23
is an axis to prevent incorrect selection. FIG. 2 is a perspective view showing the shape of the selection claw in the present invention, where 10 is the selection claw, 11 is the selection claw shaft, 12 is a disc, and 13 is a selection claw.
is an iron core.

Claims (1)

[Scope of utility model registration request] a type wheel having a plurality of type letters arranged on its outer periphery; a type wheel shaft having a groove portion on its outer periphery and supporting the type wheel for rotation;
a claw member provided on the type wheel having a spring property so as to engage with a groove of the type wheel shaft; a selection member for selectively engaging and disengaging the claw member and the groove of the type wheel shaft; A spring portion is formed integrally with the selection member, and is separated from an electromagnetic member that drives the selection member and an erroneous selection prevention shaft that faces the selection member in a standby state and prevents the selection member from malfunctioning when the selection member is on standby. A type selection mechanism for a small printer, characterized in that the erroneous selection prevention shaft is engaged with a spring.