JPS5929438B2 - printing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention comprises a platen, a rotating finger-type type wheel, a hammer-build for striking selected fingers of the type-wheel to make a mark, and a hammer-build for striking selected fingers of the type wheel, and for driving the hammer-build according to a signal. The present invention relates to a printing device having a driving electromagnetic device.

In the above-mentioned type of printing device, when making a stamp, the fingers of the type wheel that are struck by the printer vibrate in the front-rear direction (in the stamping direction) after the stamp is made. The fingers of the type wheel are typically made of relatively thin, flexible material because of the need for deflection during striking, and therefore their vibratory motion has a high amplitude and a low characteristic frequency. As a result, the vibration speed of each finger inevitably becomes slower. After stamping, the finger is subjected to residual vibration as the type wheel rotates to select the next type, resulting in an inconvenient situation where the finger gets caught on other parts of the printing device and is damaged. . In order to prevent this, a vibration damping mechanism such as a rubber damper is attached to the finger to reduce the vibration of the finger after stamping.
Rapid decay has already been proposed. However, this proposal requires special members such as a rubber damper, and has the disadvantage that it is difficult to manufacture the type wheel. The present invention aims to eliminate the above-mentioned drawbacks in conventional printing devices.

Embodiments of the present invention will be described below with reference to the accompanying drawings. In FIG. 1, a finger 5 of a finger type type wheel 4 is opposed to a platen 1 with a printing paper 2 and a ribbon 3 interposed therebetween.

The type wheel 4 is intermittently rotated by a drive motor 6, and a type character □ is formed at the tip of each finger 5, respectively. j of the finger at the marking position
There is a hammer device 8 behind, this hammer device 8 is a hammer barrel 9, and a large diameter rear part 9 of this barrel 9.
A support cylinder 10 that slidably houses the support cylinder 10, a compression spring 11 stretched between the front wall 10A of the support cylinder 10 and the large diameter rear part 9A, an electromagnet 12 and a fulcrum 13A for driving the armature 9. The actuator 13 has an actuator 13. 14 is a return spring for the actuator 13.

Type wheel 4 and its drive motor 6, . . . printing device 8
and the ribbon 3 are carried on one carrier, and this carrier moves in the axial direction of the platen around which the printing paper is wound,
Prints one line at a time. In that case, the type wheel 4 is rotated by the drive motor 6, and when the finger carrying the type to be stamped comes to the stamping position, a signal reaches the electromagnet 12 and energizes it, causing the actuator 13 to be activated by the spring 14. traction against the action of. As a result, the actuator 13 pivots around the fulcrum 13A, and its tip is...
・Hit the rear end of laser beamlet 9. The hammer print 9 moves forward against the action of the spring 11 and strikes the back of the type on the finger 1, so that the type hits the printing paper 2 wound around the platen 1 via the ribbon 3, making a stamp here. . The hammer shoot 9 is set to an initial velocity V by the actuator 13.

is decelerated by the counteraction of the spring 11 and the repulsion coefficient caused by colliding with the platen together with the finger 15, and is further biased by the action of the spring 11 and eventually reaches a speed V
1, it is assumed to be farther away from the platen. After returning to its original position at a speed of V1, the armor unit 9 bounces several times and then stops. This is shown in Figure 2 as curve 1.
Indicated by The abscissa indicates time t, the ordinate indicates position or distance, the origin is the initial position of the burlet 9, F is the initial position of the inker, B is the most advanced position of the tip of the advancing burlet, and P is the point at which the tip of the burette moves forward. represent. Finger 1 after stamping 5
begins to return from the platen at a self-oscillating speed V2 determined by its natural frequency as a cantilever.

When V2 minus V1, as is the case with conventional printing devices, the finger 5 vibrates gently in accordance with the damped vibration waveform shown by curve 1 in FIG. 2, and its amplitude is large.

The residual vibration of the finger is so large that it interferes with the rotational movement of the type wheel again in order to select the next character (see also the dashed line in FIG. 1). On the other hand, in the present invention, the material characteristics and shapes of the fingers 5 and the hammer barrel 9 and the characteristics of the spring 11 are selected so that V2>V1.

At this time, assuming that there is no burlet 9, the finger 5 attenuates according to the curve 1 which is a free vibration waveform. Again, the amplitude is relatively large and is such that the rotational movement of the type wheel for selecting the next character is disturbed.
However, in reality, the return speed V2 of the finger is greater than the return speed V of the hammer shaft V1.
Finger 1 approaches and abuts on burlet 9, and in that case... Since the mass of mercury is much larger, the energy possessed by finger 1 is absorbed in proportion to the burlet's speed, and finger 1 moves to the burlet's speed V1. Perform the corresponding reduction exercise. This is shown by the curve in FIG. In this case, it is easily understood that the residual vibration after the finger 1 returns to the initial position F is much smaller than in the case of a curved line, and the finger 1 quickly comes to rest. The fingers are preferably made of a material that is flexible, has high fatigue strength, and has a relatively high modulus of elasticity, such as fiber-reinforced nylon.

In order to be flexible and to increase the frequency of vibration, it is preferable that the fingers have a shape in which the cross section becomes larger as it approaches the base. As described above, the present invention has a simple configuration in which the return speed of the finger 1 after making a mark is made larger than the return speed of the hammer holder, so that the energy of the finger 1 is absorbed by the burlet, so that the finger 1 returns to the initial position. It has the advantage of reducing residual vibration after returning to the position, thereby preventing printing misalignment that is likely to occur due to the type wheel being pulled.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of a printing apparatus according to the present invention, and FIG. 2 is a graph showing damped vibration waveforms of a hammer print and a finger after printing. DESCRIPTION OF SYMBOLS 1...Platen, 4...Type wheel, 5...Finger, 9...Hammer buildlet, 12...Electromagnet, 13・・・・・・
・Actuator.

Claims (1)

[Claims] 1. A platen, a rotating finger type type wheel, a hammer wheel having a mass larger than the finger that strikes a selected flexible finger of the type wheel to make a mark, and driving the hammer wheel in accordance with a signal. In a printing device having an electromagnetic device, the speed of free vibration determined by the natural frequency of the finger as a cantilever after striking is greater than the speed during the return movement of the hammer burlet after striking. 1. A printing device characterized in that the finger comes into contact with the hammer barrel during a return movement, and the energy possessed by the finger is absorbed by the hammer barrel.