JPH0440187B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a small printer having a hammer drive mechanism located inside the type wheel.

[Conventional technology]

2. Description of the Related Art In printers incorporated into calculators and the like, a hammer drive mechanism is disposed within the type wheel in order to make the main body as compact as possible. This type of hammer drive mechanism is generally a suction type with a core, since it is necessary to bend the type sheet outward and press the type onto the recording paper with a predetermined pressure. For example, JP-A-56-63476
As seen in the publication, it was necessary to arrange the hammer outside the electromagnetic mechanism and to transmit the driving force of the movable core to it via the bracket.

[Problem to be solved by the invention]

Therefore, conventional hammer drive mechanisms not only have limitations in miniaturizing the device and reducing the number of parts, but also have problems such as being unsuitable for high-speed printing due to the large mass of the moving parts. had.

The present invention has been made in view of the above problems, and its purpose is to achieve miniaturization and a significant reduction in the number of parts, and at the same time, to provide a compact printer having a hammer drive mechanism capable of high-speed and accurate printing operation. The purpose is to provide printers.

[Means to solve the problem]

In order to solve the above problems, the small printer of the present invention includes a cylindrical type member having a plurality of type characters arranged around its outer periphery, and a hammer drive mechanism disposed inside the type member. A path member made of magnetic material that plays a part in the magnetic circuit, a coil bobbin that is fixed to the inside of the path member, has a coil wound around its outer periphery, and has a through hole in the center, and a coil bobbin that is fixed to the path member and has a through hole formed in the center. A fixed iron core is arranged, a movable iron core is slidably arranged in the through hole, and a hammer is slidably inserted into the through hole of the coil bobbin and engages with the movable iron core to press the type, The hammer is
It is characterized in that it includes a flexible engagement portion that engages with the movable core in a non-fixed manner and slides integrally with the movable core.

〔Example〕

Therefore, details of the present invention will be explained below based on illustrated embodiments. In this embodiment, an example will be described in which the path member is divided into a yoke 1 and a lid 7.

The drawing shows one embodiment of the present invention, and reference numeral 1 in the drawing denotes a common yoke with a U-shaped cross section that is disposed inside the printing wheel 20 along its axis. At the edge, each digit (type sheet 21
2 if the type 22 is arranged in a staggered manner.
A notch 2 is provided in each column (for each type character in a row), and a fitting hole 3 for a coil bobbin 4 is similarly bored in each girder on the inner wall surface, and a convex portion 6 protruding from the flange 5 is provided in the yoke 1. A large number of coil bobbins 4 are caulked into the notches 2 and are fixedly installed with their tips protruding outward from the fitting holes 3.
Reference numeral 7 denotes a lid made of a magnetic material that closes the open end of the yoke 1. Two holes 8 and 9 communicating with the inside of the coil bobbin 4 are bored in this surface for each column.
One hole 8 is used for caulking a protrusion 11 of a fixed iron core 10 that is arranged eccentrically on one side of the inside of the coil bobbin 4, and the other hole 9 is used to ensure accurate movement of a hammer 14, which will be described later. It is configured as a guide for

On the other hand, the hammer 14 described above is formed of thermoplastic resin into a substantially rod shape, and is inserted into the coil bobbin 4 through a gap provided on the other side of the fixed iron core 10 from the hole 9 of the lid body 7. And one end 15
protrudes outward from the hole 9 of the lid body 7 and is curved along the central axis of the coil bobbin 4.
The other end of the coil bobbin 4 protrudes outward from the tip of the coil bobbin 4 and engages with the protrusion 13 of the movable iron core 12. In addition, the tip of the hammer 14 is formed as an arrowhead-shaped head 16 for guiding the insertion of the movable iron core 12 through the thinned portion created by providing the recess 17.

In the figure, reference numeral 18 is a permanent magnet attached to the outer edge of the fitting hole 3 provided in the inner wall of the yoke 1 in order to attract and urge the movable core 12 outward, 24 is an ink roller, and 25 is a paper. A feed roller 26 indicates a pressure roller, and in FIG. 2 showing a side view of this printer mechanism, a reference numeral 27 indicates a motor integrated with the printing wheel, and a reference numeral 28 indicates a motor coil.

Next, to explain the assembly procedure of the hammer drive mechanism described above, first, a large number of coil bobbins 4 are assembled inside the yoke 1, a lid body 7 is attached from above, and a fixed iron core 10 caulked to the back side of each coil bobbin is attached. Position within 4. Next, insert the hammer 14 into the coil bobbin 4 through the hole 9 of the lid body 7, make the tip of the hammer 14 protrude from the tip of the coil bobbin 4, and finally push the movable iron core 12 through the tip of the coil bobbin 4. The head 16 provided at the tip of the hammer 14 bends outward when the movable iron core 12 is inserted into the coil bobbin 4, and returns to its original position when the protrusion 13 engages with the recess 17. After returning, moveable iron core 12
Become one with.

In the hammer drive mechanism configured in this way, the permanent magnet 18 attached to the outer surface of the inner wall of the yoke 1 constantly biases the movable core 12 in a direction to protrude from the coil bobbin 4. is located away from the protrusions 23 on the back surface of the typeface 22 when electricity is not applied. Then, when the printing coil is energized by the printing command signal, the movable iron core 12 attracted to the fixed iron core 10 projects the hammer 14 that is integrally engaged through the protrusion 13, and pushes the type sheet 21 outward. One selected printed character 22 is brought into contact with the recording paper by bending.

Therefore, by penetrating the hammer body into the coil bobbin and having a part of it engage with the movable core, it is possible to downsize the hammer drive mechanism to the same size as the coil bobbin, and at the same time, the hammer body By making the distance between the movable core and the movable core substantially zero, the responsiveness can be improved.

In addition, the hammer body is made of a flexible material, and the part protruding from the coil bobbin is provided with a guide slope for inserting the movable core and an engagement recess following the guide slope, so that the hammer body formed by the engagement recess has a thin wall. By using this section, the movable core can be inserted into the coil bobbin and engaged with the hammer body at the final stage of assembly, thereby greatly improving assembly efficiency.

〔Effect of the invention〕

As explained above, according to the present invention, in a small printer equipped with a cylindrical type member having a plurality of type characters arranged around the outer periphery and a hammer drive mechanism disposed inside the type member, a magnetic circuit can be used. A coil bobbin is fixed to the inside of the channel member and has a coil wound around its outer periphery and a through hole is formed in the center. a fixed iron core, a movable iron core that is slidably disposed in a through hole, and a hammer that is slidably inserted into a through hole of a coil bobbin and engages with the movable iron core to press the type; , is equipped with a flexible engagement part that engages with the movable core in a non-fixed manner, and slides integrally with the movable core. It is possible to incorporate or remove the movable core and hammer by bending the engaging part of the
Even if malfunction or wear occurs due to the hammer or the movable core, it can be easily replaced, but the hammer and the movable core can be replaced independently.

Therefore, it is possible to easily improve the initial functional quality, or to improve responsiveness by adjusting the gap with the fixed core by replacing the fixed core.
Also, it becomes easy to change the operating stroke of the movable iron core.

Furthermore, assembly costs and parts costs can be reduced, and there is no need to fix the hammer and movable core.
Since no parts are required to connect the movable core and the hammer, a low-cost hammer drive mechanism can be provided.

As described above, according to the invention, it is possible to provide a small printer that is highly reliable, has wide applicability, and is inexpensive, and has extremely large practical effects.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a hammer drive mechanism according to an embodiment of the present invention, and FIG. 2 is a side view showing an example of a small printer equipped with the above drive mechanism. 1... Yoke, 4... Coil bobbin, 7... Lid body, 1
0... Fixed iron core, 12... Movable iron core, 14... Hammer, 16... Arrowhead-shaped head, 17... Engagement recess, 20
...Print wheel.

Claims (1)

[Scope of Claims] 1. In a small printer equipped with a cylindrical type member having a plurality of type characters arranged around its outer periphery and a hammer drive mechanism disposed inside the type member, a part of the magnetic circuit. a coil bobbin fixed to the inside of the channel member, having a coil wound around its outer periphery and a through hole formed in the center; and a coil bobbin fixed to the channel member and arranged in the through hole. a fixed iron core that is slidably disposed within the through hole; and a hammer that is slidably inserted into the through hole of the coil bobbin and engages with the movable iron core and presses the type. A small printer, wherein the hammer includes a flexible engagement portion that engages the movable core in a non-fixed manner, and slides integrally with the movable core.