SU1214491A1 - Printing unit - Google Patents

Description

The invention relates to office equipment and can be used in percussion printing devices.

The aim of the invention is to improve print quality.

FIG. 1 shows the print unit, general view; in fig. Figure 2 shows the interaction of a printing hammer with a letter carrier.

The print unit contains a printing mallet 1 with a tip 2, made not from elastic elastic material, and a shape convex in the direction of the letter carrier, a letter 3, having round signs 4,

The radius of curvature of the working surface of the hammer is directly proportional to the radius of curvature of the working surface of the mark on the bearer.

Mr. KR,

where g is the radius of curvature of the working surface of the hammer; R is the radius of curvature of the working surface of the character on the literary gauge;

To the coefficient of proportionality.

The printing hammer 1 is installed in guides 5 and 6 and is driven by the hammer 7 by means of an electromagnet 8. The hammer 1 returns to its initial position due to the spring 9. The stroke of the hammer 1 is adjusted by screw 10,

The print node works as follows.

When the carrier 3 rotates, for each of its rotation marks 4 alternately occupy the print position opposite the hammer K, At the moment when the mark 4 selected for printing is in the print position, an electrical signal (command) is received from the control unit (not shown) to the electromagnet 8, which, when triggered, rotates the hammer 7 around axis 1. The drummer 7, turning the wok of the axis, hits the stem of hammer 1 and moves it in the direction of the literal carrier 3. The hammer strikes paper 12 and the paint mite 13 according to sign 4, at, this elastic tip Under the influence of the impact force, the jigger 2 is deformed on the surface of the radius of curvature of the sign 4 and is tightly pressed with aet 12 and the dye tape 13 to it, as a result of the paper 1449 2

ha, an imprint of the desired mark 4 is obtained. The kinetic energy acquired by the hammer is almost completely converted into potential energy of deformation of the dye tape 13, paper 12 and tip 2. After impact, part of the potential energy is converted into kinetic energy of the hammer rebound and recovery

to the original shape of the tip 2,

and the remainder is dispersed during the process of transferring ink to paper 12 and to plastic deformation of dyeing tape 13 and paper 12. After the father; The hammer returns to its initial position by the spring 9 through the drummer 7 and is held until the signal (command) for the next character is received. Next cycle

20 printing is repeated,

As an elastic elastic material for the head (anvil), urethane elastomers J can be used, for example, SKP PFP-90,

25 The value of the coefficient of proportionality can be determined, for example, by the following method.

Fig. 2 shows geometric constructions by which we determine the coefficient of proportionality K. The initial position of the tip 2 of the hammer 1 in Fig. 2 is indicated by a dash-dotted line,

In determining K, we proceed from Toros that the material of the tip of the malleus is practically incompressible, and the chord 2c of the working surface segment of the malleus tip is equal to the chord 2B of the working surface of the mark on the letter carrier.

thirty

35

40

2B 2c

(2)

The tip 2 of the hammer 1, moving by the magnitude of the arrow t, under the action of the printing force, deforms tightly against the working surface of the sign on the letter carrier Back and takes the form indicated in FIG. 2 with a solid line, filling the surface F and 5, Therefore, T1 square

C F + S,

(3)

5- where S is the area of the tip segment of the hammer 1 formed by an arc of radius r and chord 2c;

F is the area occupied by the material (in the plane of the drawing), displaced by the sign 4 of the letter carrier 3 when it is inserted into the body of the tip 2 of the hammer.

, ()

de S. is the area of the character-carrier segment of the radius R and chord 2B. Area 3, defined as

S. 2Bt - S ,.

where t is the arrow of the sign segment of the litas

ronitel

Substituting (4) and (5) into (W), we get

3 2Bt, (6)

For practice with a sufficient degree of accuracy can be accepted

(7)

S, I (2.Bt,)

The relative error of formula (7) is no more than 0.3%. From (6) and (7) follows

t, | t

(eight)

According to the well-known formula chord segment

2В 2 ytl2R tr (9) Therefore, the equality (2) we accept can be written as

121449

t (2R-t) t, (2.r-g,

(ten)

Substituted (8) in (U). will get

 ), e2

)

e wk.

(eleven)

Consequently, the proportionality coefficient we determine

(12)

ten

K-3

five)

but

at (6)

(7)

uly

(eight)

Yes

(9) veinsApplication of a hammer with a convex working surface of a tip made of an elastic material allows the paper and dyeing tape to fit snugly across the entire working surface of the mark on the letter carrier. Due to the fact that at the moment of printing the working surface of the nebnik, having elastic properties in contact with the sign on the thermal carrier, under the action of the seal, it gradually deforms and takes on the exact shape of the sign surface regardless of the purity of the mechanical surface. surface treatment, skewing or displacing the malleus with respect to the letter carrier. In addition, the absence of such elements as whiskers inherent in hammers with a concave working surface on the concave working surface of the tip eliminates the appearance of undesirable impressions around the printed sign 3S

strokes and cls, making it difficult to read the printed text unambiguously.

BNIIPI Circulation 363

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Branch ShSh Patent Propulsion Uzhgorod, 4 Project

Claims (1)

A PRINT ASSEMBLY containing a letter carrier having convex signs and a printing hammer interacting with it with a tip, characterized in that, in order to improve print quality, the tip is made of elastic material and its working surface has a convex shape towards the letter carrier, the radius of curvature of the working surface of the tip is directly proportional to the radius of curvature of the working surface of the character of the letter carrier, QJue.f 1 12