SU878597A1 - Electromagnetic printing head - Google Patents

Description

one

This invention relates to electromagnetic print heads.

A known electromagnetic print head containing a printing punch located in a frame, on which a coil is wound, a cylindrical spring and measles located inside the frame

1. The disadvantage of the known electromagnetic

The printhead is low reliability.

The aim of the invention is to increase the reliability of the operation of the electromagnetic print head.

The goal is achieved by the fact that it has a cylindrical acoustic chamber installed inside the frame, an additional roller, electrically connected to the main roller, and a stepped panel, at each step of which spherical reflectors are mounted, and the measles is made in the form of a hollow cylinder, placed in the acoustic chamber and it is spring-loaded to its base, with the step-like panel installed in the core cavity, and the printing punches are placed in the respective reflectors of the step-like panel.

FIG. 1 shows a print head, a cross-section; in fig. 2 is a timing chart for controlling the operation of the print head.

The electromagnetic printing head contains a cylindrical magnetic circuit 1 5 with a slit 2, inside there is located an exciter 3 with a winding 4 located on the frame 5; on one side, the coil 3 is closed with a magnet with a soft back cover 6, on the other - a washer 7, into the frame

10 5 on the side of the washer 7, a flange core 8 is inserted, which is a washer with a glass made in the form of a cylinder or a straight parallelepiped, a continuation of the core is measles 9, a certain working air gap is established between the core and the flange core. Through the hole in the bottom of the glass core 9 and the window of the core 8 passes the printing punches 10, which then

20 is freely covered by an additional coil 11, consisting of a winding 12 wound on a frame 13. To completely close the magnetic flux, the coil I is covered with magnetically soft ferrite shields 7,

25 14. There is also a matrix 15. The ink ribbon 16 is positioned between the paper 17 and the matrix 15, which is pressed against the groove of the magnetic plate 14 or against the body of the head with the help of a disk cover 18,

30 having a threaded connection with the housing 1. The ends of the punches 10 located inside the hollow core 9 are fixed in the geometric center of the spherical reflectors 19, each of which represents a part of the spherical surface, the radius of which strictly corresponds to the length and speed of propagation of ultrasound in the printing junction box. Punches have different lengths and are located on the steps. All reflectors 19 form an acoustic reflector, which is located in the acoustic chamber 20. The position of the acoustic reflectors can be adjusted inside the chamber 20 by mixing the reflectors in a plane normal to the drawing of FIG. 1. Acoustic reflectors are located on the panel 21, which in turn does not transmit ultrasound to the back of the head, and contributes to the reflection of the signal into the cavity of the core 9 and jones 10. The return cylindrical spring 22 is located between the poles of the flange 8 and the core 9. In the initial state These measles 5 are pressed by the spring 22 to the vibration-absorbing gasket 23, the liners 24 hold the coils and washers in a fixed position. To reduce the resistance to movement of the core 9, the rear part of the head has an opening 25 in the cover 6. In FIG. 2 the following notation is accepted: LT is a pulse of electromagnet control of a head of duration G1; t is the time of the supply of punches to the paper; W is the angular frequency of the control clock; - sync signal at the distributor output; U1-U8 - information signal at the output of the character generator, the signal of the column; bvyh - control signal winding additional coil. The operation of the electromagnetic print head is carried out as follows. A control signal T1 (see Fig. 2a) is sent to the head on the roller 3. In the excitation winding 3, an F1 magnetic field arises, which creates a strong induction field B1 through the magnetic gap of the electromagnet 1 , cover 6, flange core 8, measles 9, this field induces various poles L / and 5 in the poles of the flange core 8 and core 9. The magnetic poles of the core and the flange core of the electromagnet interact, resulting in ate whose armature 9 starts to be attracted to the core 8. Anchor 9 for time n carries the punches 10 to the printing position. After that, high-frequency signals are fed into the coil 11. The magnetic field generated here in winding 12 and amplified by magnetic shields 14 and 7 (magnetic field F2) acts on punches 10, which under the influence of a constant magnetic field F1, until the appearance of field F2, were in a compressed state. Under the action of the opposite field F2, the main magnetic field F1 is weakened in rods x 10. The size of the rods begins to increase in accordance with the actual control signal (see Fig. 2e). An elastic compression-rarefaction front appears in the rods. This front moves at high speed in two directions — towards the working end of the punches — the first direction, the second towards the electromagnet 9. The fronts in all the rods move in the same way, and the moment of arrival of the deformation front to the opposite ends of the punches is different. Working, vibrating or slightly deforming the front of the wave, the punches 10 begin to transmit high-speed oscillation to the air, forming the front of the air wave. There is an addition of two speeds: the speed of the supply of punches and the speed of vibration, but the speed of vibration is much greater than the speed of the supply of punches (for example, 5-10 times). An elastic sound wave will propel the ink ribbon 16 to the paper 17. This reduces the notii in the electric drive of the head. The second wave front at different times reaches the other ends of the punches 10, which are connected to acoustic reflectors 19. The unequal arrival of the wave front in the rods to the reflectors is explained by their different length, which was calculated in advance. At the expense of the reflectors 19, the forward wave is reflected in the opposite direction. With the arrival of the second high-frequency pulse, the arising second wave front in the rods begins to fold with the reflected fronts of the first control sigal. The system is constructed in such a way that in one of the punches the wave front increases dramatically and the punch during subsequent pulses begins to work as a resonant element. In other punches 10, on the contrary, there is a sharp decrease in the wave front, since the pump signal does not coincide with the natural frequencies of the punches 10. This is how one of the punches works at the corresponding one control frequency fi. With an increase in the amplitude of oscillations of one of the punches 10, an increase in the density of the shock air wave occurs, the diameter of the punch in the working part increases as it were, a sharp pressing of the dye tape occurs to the paper at this point. The punch repeatedly hits one place. The paper, which is deformed under the punch, is filled with paint in a deformable area, as it were, faster and more evenly. After the prints of the first point, a signal of the frequency fz is given, and the second punch begins to oscillate, etc. Thus, an imprint of one vertical line of the symbol in one

decomposition column sign. After that, the control signal t / t from the electromagnet is removed and under the action of the spring 22 the bore 9 with the punches 10 comes to its original state. When the next mark element is printed in the second column, the decomposition of the sign of the gologzka works in a similar way.

Panel 21 is at an angle to the direction of movement of the punches, which contributes to a better amplification of reflected wave fronts in the punches, and acoustic chamber 20 contributes to maintaining the echo signals at a certain level, due to the stepped design of the panel in the chamber. To reduce the noise level upon returning the punches 10 to the initial state, a sound-absorbing pad 24 is located between the cover 6 and the core 9.

Claims (1)

1. Patent information No. 2231203, cl. B 41 I 3/10, 1974. 2 / 25 tn . |.  I / j l / 5 y "/, / f / r ui