JPH01308659A - Small-sized printer - Google Patents

Abstract

PURPOSE:To attract and energize a plurality of movable cores by the use of a common permanent magnet and to largely reduce the number of components by disposing a permanent magnet for energizing the cores engaged with hammers in a direction for separating it from a stationary core on the outer wall of a yoke along a plurality of coil bobbins. CONSTITUTION:A hammer driving mechanism is associated by sequentially assembling a stationary core 11 and a hammer 15 with a yoke 1, and externally deflecting the end of the hammer 15 from the open end side of a coil bobbin 6. Since a movable core 12 is always energized in a direction for separating from the core 11 by a permanent magnet 19 attached to the outside of the inner wall 4 of the yoke 1, the hammer 15 integral therewith is separated from the protrusion 23 on the surface of a type 22 at the time of nonconduction, the hammer 15 integral with the core 12 through a protrusion 13 attracted to the core 11 protrudes the core 12 attracted to the core 11 protrudes from the core 12 each time a typing coil is conducted by a type command signal, a type sheet 21 is externally deflected, and a selected type 22 is made to abut on a recording sheet.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a compact printer with a hammer drive mechanism.

[Prior Art] For example, in a printer built into a calculator, etc., in order to make the main body as compact as possible, a hammer drive mechanism is disposed within the type wheel, and the type sheet is bent outward to apply a predetermined pressure to the type. It is configured to be brought into pressure contact with the recording paper. For this reason, a suction type printer with a core is generally used in this type of printer, but for this reason, as seen in Japanese Patent Application Laid-Open No. 56-63476, springs are installed on each movable core. This spring force is configured to keep the hammer away from the type when no electricity is applied.

[Problem to be solved by the invention 1 Therefore, in the conventional hammer drive mechanism.

This method not only requires a large amount of spring members and takes a lot of effort to assemble, but also has the problem that uneven printing occurs due to variations in the force of the individual springs.

The present invention has been made in view of the above problem, and its object is to provide a hammer drive mechanism for a small printer that is simple in construction and does not cause printing blanks.

[Means for Solving the Problems] That is, a small printer according to the present invention includes a cylindrical type sheet (21) in which a plurality of type characters are arranged around the outer periphery, and a cross section that is approximately mouth-shaped and has a fitting hole (21) at the top. A yoke (1) is provided with a yoke (5) and placed inside the type sheet, and a plurality of coil bobbins (6) are fixed inside the yoke, have coils wound around the outer periphery, and have a through hole in the center. ), a fixed core (11) provided in the through-hole, a movable core (12) slidably supported in the fitting hole, and 5) fixed to the yoke, which is connected to the movable core when not printing. It is characterized by having a permanent magnet (19) to which the movable iron core is attracted so as to create a gap between it and the fixed iron core.

[Example] The details of the present invention will be explained below based on the illustrated example.

The drawing shows one embodiment of the present invention, and the reference numeral l in the drawing represents a common yoke with a U-shaped cross section that is disposed inside the printing shaft 20 along its axis, and its side wall Cuts 3 are provided on the edge of 2 for each digit (every 2 digits in the case of a type sheet 21 in which the type 22 is arranged in a staggered manner), and the inner wall surface 2 is provided with a notch 3 for fitting the coil bobbin 6. Matching holes 5 are similarly drilled for each digit, and a large number of coil bobbins 6 are inserted into the notches 3 through the protrusions 7 on the flanges inside the yoke l.
It is fixedly installed so that its tip protrudes outside the fitting hole 5 of the yoke I. 8 is a lid made of lin material that closes the open end of the yoke l.

This surface has two holes 9 communicating with the inside of the coil bobbin 6.
．． 10 are drilled in each digit, one hole 9 is for caulking a fixed iron core 11 which is disposed on the inside side of the coil bobbin 6, and the other hole 10 is to be described later. It is configured as a guide to ensure accurate movement of the hammer 15.

On the other hand, the hammer 15 described above is formed of thermoplastic resin into a substantially rod shape, and is inserted into the coil bobbin 6 from the hole lO of the lid 8 through a gap provided on the other side of the fixed core 11, and one end 16 of the hammer 15 is inserted into the coil bobbin 6 through a gap provided on the other side of the fixed core 11. 8 and is curved along the central axis of the coil bobbin 6, and faces the convex 1'+ja 23 on the back surface of the type 22 on the type sheet 21 wound on the printing shaft 20. In addition, the other end protrudes from the tip of the coil bobbin 6 to the outside, and that part is formed into a recess 17 that engages with the protrusion 13 of the movable core 12. Furthermore, a recess I7 is provided to form a thinner part. An arrowhead-shaped head 18 for guiding the insertion of the movable iron core 12 is formed at the tip thereof.

By the way, the reference numeral 19 in Figure 1 is a permanent 6n stone, which is a characteristic feature of the present invention and is arranged to actively keep the movable core 12 separated from the fixed core 11 when the current is not applied. 4 and a fitting hole 5 drilled therein.
A hammer 15 is integrally fixed to the opposite side with a 6n pole facing the movable core 12. With this configuration, the protruding end 14 of the movable core 12 protruding from the tip of the coil bobbin 6 can be magnetically attached to the opposite side of the movable core 12. It is designed to attract the air and constantly force it outward.

This permanent magnet 19 is also configured as a rod-shaped body coupled so that the magnetic pole faces the movable iron core 12, and by fixing this to the outside of the inner wall 4 of the yoke l, all the movable iron cores 1
It is configured so that the suction force is applied equally to 2.

In the drawing, reference numeral 24 indicates an ink roller, 25 indicates a paper feed roller, and 26 indicates a pressure roller. In addition, in FIG.
28 indicates a motor integrated with the printing shaft, and 28 indicates a motor coil.

The hammer drive mechanism described above sequentially assembles the coil bobbin 6, the fixed core 11 integrated with the lid 8, and the hammer 15 to the yoke l, and then finally bends the tip of the hammer 15 outward from the open end of the coil bobbin 6. It can be assembled by pushing the movable iron core 12 while moving it. With this configuration, the movable iron piece 12 is always attached to the fixed iron core 1 by the permanent magnet 19 attached to the outside of the inner wall 4 of the yoke l.
Since the hammer 15, which is integrated with the hammer 15, is biased in the direction away from the protrusion 2 on the back side of the type 22, when the power is not energized,
3, and each time the printing coil is energized by a print command signal, it is fixed and bends the type sheet 21 outward so that one quickly selected type 22 comes into contact with the recording paper. become.

Although one or more examples have been explained using a small-sized printer disposed inside a type wheel, the hammer drive mechanism according to the present invention can also be applied to other small-sized printers.

[Effects of the Invention] As described above, according to the present invention, a permanent Knite that biases the movable iron core that engages with the hammer in a direction away from the fixed iron core is arranged on the outer wall of the yoke along the plurality of coil bobbins. Since multiple movable iron cores are connected to a common permanent 67
? In addition to being able to attract and energize with a stone, which greatly reduces the number of parts, it can also be attached to a part of the yoke separately from the movable iron core, making assembly extremely easy. be able to.

Moreover, the substantially uniform biasing force generated by the common permanent magnet makes it possible to equally control the striking force of the hammer, thereby greatly improving the printing quality of this type of printer.

4 Brief Description of the Figures FIG. 1 is a side sectional view of a hammer drive mechanism which is an embodiment of the present invention, and FIG. 2 is a plan sectional view showing an example of a small printer equipped with the above drive mechanism.

l...Yoke 6...Coil bobbin 12...Movable iron core 15...hammer 19...Permanent magnet 20...Printing axis that's all Agent: Kisanbe Suzuki (1 other person)

Claims (1)

[Claims] A cylindrical type sheet (21) in which a plurality of type characters are arranged around the outer periphery.
a yoke (1) having an approximately n-shaped cross section, a fitting hole (5) provided at the top, and disposed inside the type sheet; and a plurality of coil bobbins (6) each having a through hole in the center thereof, a fixed iron core (11) provided in the through hole, and a movable iron core slidably supported in the fitting hole. (12)
and a hammer (15) provided with an end (16) for pressing the type, engaged with the movable core and disposed within the through hole.
and a permanent magnet (19) which is fixed to the yoke and attracts the movable core so as to create a gap between the movable core and the fixed core when not printing.