JPH0595743U - Type ring selection mechanism - Google Patents

Abstract

(57) [Summary] [Structure] The selection shaft 13 is made of a non-magnetic material, and prevents the magnetic force lines formed when the electromagnetic coil is energized from flowing into the selection shaft 13. [Effect] Since the material of the selection shaft is a non-magnetic material, the magnetic lines of force do not flow out to the selection shaft when the electromagnetic coil passes through the electromagnetic field, and the electromagnetic efficiency is improved to perform the adsorption operation.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a character wheel selection mechanism for selecting an appropriate character wheel based on a print command content and stopping the character wheel in a printer at a printing position.

[0002]

[Prior Art]

 Conventionally, this type of technology has been proposed in the case where two selective pawls are separately driven on both end faces of one electromagnetic clutch as shown in Japanese Utility Model Publication Nos. 63-60334 and 63-60335. The electromagnetic clutch and rotary sleeve that are integrated with the selection shaft, which is a magnetic material such as free-cutting steel, attracts the selection claws using electromagnetic means and drives the selection claws in the selected direction to position the type wheel at the proper position. The selection claw engages with the locking recess of the type wheel to stop at.

[0003]

[Problems to be solved by the device]

 However, in the above-mentioned conventional technology, since the material of the print shaft is a magnetic material, a part of the magnetic field lines formed when the electromagnetic coil is energized flows into the selection shaft, which reduces the electromagnetic efficiency. However, there was a problem that the rotary sleeve integrated with the electromagnetic clutch and the selection claw were not attracted, and the type could not be selected. The present invention has been made to solve such a drawback, and an object thereof is to provide a type wheel selecting mechanism with improved functional quality.

[0004]

[Means for Solving the Problems]

 The type wheel selection mechanism of the present invention includes a selection shaft that is constantly rotating, an electromagnetic clutch having an electromagnetic coil through which a rotating sleeve that rotates in conjunction with the selection shaft is passed, and an elastic clutch at both ends of the rotating sleeve. A pair of plates that are in contact with each other and are attracted to the rotary sleeve when the electromagnetic coil is energized and rotate integrally. The selection claw that rotates in the rotation direction to stop the type wheel and the plate that always rotates. In a type wheel selection mechanism having a plate with a magnetic field closing tongue that receives a driving force in the direction of rotation by sandwiching the driving plate that is in motion, the passage of magnetic field lines formed when the electromagnetic coil is energized. It is characterized in that the material of the selected shaft, which is a part of, is non-magnetic material.

[0005]

[Action]

 According to the above configuration of the present invention, a part of the magnetic force lines formed when the electromagnetic coil is energized does not flow into the selection shaft, and the electromagnetic efficiency is improved.

[0006]

【Example】

 Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an embodiment of a type wheel selection mechanism of the present invention, and FIG. 1 (a) shows a state in which it is stopped at an initial position. The type wheel 41 and the plate 10 that engages with the type wheel 41 are provided with the number of print digits, and the electromagnetic coil (not shown) is a two-digit electromagnetic coil type that rotationally drives two adjacent plates 10. is there. In the plate 10, the selection claw 11 is elastically pressed in the selection direction (counterclockwise direction in the figure) by the elastic force of the restraining spring 20, but the locking claw 12 is engaged with the lower side of the crest 21a of the locking spring 21. Has been localized to the initial position.

Next, a print start command is issued, and at the same time, the drive motor (not shown) is energized, and the cam shaft 30, the type shaft 40, the selection shaft 13, and the drive shaft (not shown) are respectively moved to the positions shown in FIG. The rotation starts at a predetermined speed in the direction of the arrow in (a). At this time, the plates 10 arranged on both sides of one electromagnetic clutch (not shown) make elastic contact with both end surfaces of the rotary sleeve 14, and each magnetic field closing tongue 15 and a drive plate (not shown). While being elastically contacted, it receives rotational force in the selected direction, but it is held stationary at the initial position by engaging the locking claw 12 with the crest 21a of the locking spring 21 downward.

Next, type selection is performed. As shown in FIG. 1B, the reset cam 32 of the cam body 31 is disengaged from the engagement position with the scooping protrusion 16 of the plate 10, and the type body to be selected first among the pair of type wheels 41. When the locking recessed portion 43 of the selection ratchet 42 corresponding to (4) rotates to a position facing the selection claw 11 of the plate 10, a type selection command is issued to the electromagnetic coil of the electromagnetic clutch. That is, a type selection command (not shown) consisting of pulses is generated at substantially the same time as the time when the central angle of the locking recess 43 is rotated. A closed magnetic field is formed at the same time when the electromagnetic coil is energized, and the plates 10 and the rotary sleeve 14 are strongly attracted to each other by the magnetic force, the rotating force of the selection shaft 13 and the trigger-reinforced rotation of the drive plate (not shown). Due to the force and the elastic force of the restraining spring 20 to a small extent, only the plate 10 on which the selection claw 11 faces the locking recess 43 rotates in the selection direction, and at the same time, the locking claw 12 suppresses the spring force to a small level. The mountain portion 21a of the obtained locking spring 21 is lightly crossed over from below with a small force, and the tip of the selective pawl 11 is engaged with the locking recess 43 and stopped. In this case, the other plate 10 is brought into contact with the projections between the selection ratchets 42 having the half-pitch phase difference and the adjacent selection recesses 43 and the locking recesses 43 adjacent to each other, so that the selection claw 11 moves in the selection direction. Movement is blocked.

However, when the material of the selection shaft 13 is a magnetic material, a part of the magnetic force lines formed when the electromagnetic coil is energized flows into the selection shaft 13 and the electromagnetic efficiency between the rotary sleeve 14 and the plate 10 decreases, and eventually. The plate 10 and the rotary sleeve 14 cannot be attracted to each other, but since the material of the selection shaft 13 is a non-magnetic material, the magnetic lines of force formed when the electromagnetic coil is energized do not flow into the selection shaft 13 and the plate 10 and the rotary sleeve 14 Suction is performed accurately, and stable selection operation can be performed without causing malfunction.

As described above, in the present embodiment, the material of the selection shaft is made of a non-magnetic material, so that the electromagnetic efficiency between the selection pawl and the rotary sleeve is improved and the suction operation is performed.

[0011]

[Effect of the device]

 As described above, according to the above configuration of the present invention, a part of the magnetic force line formed when the electromagnetic coil is energized does not flow into the selection shaft, and the electromagnetic efficiency of the selection pawl and the rotary sleeve is improved, so that the adsorption operation is performed. Is done. Further, the capacity of the electromagnetic coil and the drive motor can be reduced, and the power consumption can be reduced. In this way, by reliably performing normal typeface ring selection operation, it is possible to provide a typeface ring selection mechanism with improved functional quality, and the effect is great.

[Brief description of drawings]

FIG. 1 is a side view showing an operating state of a type wheel selection mechanism according to an embodiment of the present invention.

[Explanation of symbols] 10 plate 11 selection claw 12 locking claw 13 selection shaft 14 rotating sleeve 15 magnetic field closing tongue 16 scooping protrusion 20 restraining spring 21 locking spring 21a mountain portion 30 cam shaft 31 cam body 32 reset Cam 40 Type shaft 41 Type ring 42 Selection ratchet 43 Locking recess

Claims (1)

[Scope of utility model registration request] 1. A selection shaft which is always rotating, an electromagnetic clutch having an electromagnetic coil through which a rotation sleeve which rotates in conjunction with the selection shaft is penetrated, and both ends of the rotation sleeve are elastically contacted. Together with the pair of plates that are attracted to the rotating sleeve and integrally rotate when the electromagnetic coil is energized, the pair of plates rotate in the rotating direction to stop the type wheel, and always rotate. In a type wheel selecting mechanism having a plate having a driving plate sandwiched therein and receiving a driving force in the rotating direction, a plate having a plate having a magnetic field closing tongue, and A type wheel selecting mechanism, characterized in that the material of the selection shaft as a part is a non-magnetic material.