DE1279983B - Print hammer unit for high-speed printer - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. α .:

G06k

German class: 42 m6 -15/02

Number: 1279 983

File number: P 12 79 983.6-53 (H 56166)

Filing date: May 28, 1965

Opening day: October 10, 1968

The invention relates to a print hammer unit for high-speed printers, in which the individual print hammers held by spring force with bias against their stop movement in their rest position and can optionally be driven against the paper to be printed by actuating levers, with dampers to suppress the vibrations that occur when the hammers return.

Using a printer with a movable type carrier and optionally moving print hammers are high To achieve printing speeds, however, there are high demands on the timing of the Print hammer actuation provided. In order to be able to keep the same distances, the time of the Impact of the print hammer on the moving type carrier must be precisely controlled. The repeated Execution of such control requires that each time the print hammer is actuated, the the same force is applied from the same respective position.

It is known to preload the print hammer of a high-speed printer in the rest position so that it touches an actuating lever, which in turn lies against a rear stop. Becomes the operating lever excited, then the print hammer is quickly moved forward onto the moving type carrier, from which it ricochets off and, partly through the influence of the preload springs, back into his Rest position returns. The hammer normally returns to its rest position at high speed back, so that when the back of the print hammer hits the actuation lever, he of this ricochets off again. This second ricochet happens in the forward direction and causes under Under certain circumstances, a so-called shadow print on the paper. When the print hammer by the actuator arm is thrown forward while still in the ricochet motion, d. H. before going in its rest position has returned, then neither the force transferred to the print hammer nor its Way the same as with the previous hammer operation. Correspondingly, the time gives way which he needs for the way and his impact on the type carrier, which has the consequence that the position of the printed mark deviates from the norm. If the type carrier is a rotating roller is whose raised types are moved in cells past the printing location at each print hammer, then, if the journey time differs, the character is printed above or below the print cell. if the type carrier is designed in the form of a chain or a belt that aligns parallel to the print hammer unit for high-speed printers

Applicant:

Honeywell Inc., Minneapolis, Minn. (V. St. A.)

Representative:

Dipl.-Ing. R. Mertens, patent attorney,

6000 Frankfurt, Neue Mainzer Str. 40-42

Named as inventor:

Ross A. Belson, Framingham, Mass. (V. St. A.)

Claimed priority:

V. St. v. America June 11, 1964 (374 339)

The last row of print hammers moved past the printing site then changes in the travel time of a print hammer cause a change in the Position of the printed character along the print line.

Assume that it is a printer with type roller, the z. B. 1000 lines per Minute, the actual printing of a line can take about 45 milliseconds and a duration of about 15 milliseconds for the subsequent paper feed. During this last period, the print hammers must return to their rest position in good time that they are fully operational even in the worst case, d. H. if the last one used Print hammer from the last print cycle is actuated first in the following print cycle. Should higher print speeds can be achieved by reducing the print and paper feed cycles then, of course, the rebound interval of the hammer that occurs when the hammer is actuated not be a limitation of this progress.

Various damping methods have been proposed to reduce the rebound vibrations of the Pressure hammer to dampen faster; so far none has been completely satisfactory. One execution is between the rear stop of each operating lever and a fixed support an elastic material provided to the outgoing from the returning hammer and transmitted via the stop Absorb shock. It has been found that when such an arrangement is carried out at high speed

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is operated, under unfavorable conditions - that is, the front print hammer part ends in a conwhen the last hammer operated is the first to be cave again, the impact surface 22, which is operated in front of the characters - there may still be vibrations or types 14 while these can be on the print, the deviations in the service time of the station pass by. The rear hammer part 18 hammer on the pressure roller during the following 5 ends in a convex impact surface 24, which cause pressure cycle. Apart from the fact that there is an actuating lever 26 when it is expensive to carry out such an arrangement because the print hammer 10 is in its rest position. Each stop must be equipped individually, operating lever can be done on a fixed rear Anes that the rest position of the hammer hit 28. The print hammer 10 is moved by two after repeated use because the io leaf springs 30 are held, which is compressed on the front part or elastic material. A rear part of the hammer are attached. The springs such change increases the distance that everyone has to travel with a hammer carrier 32 verbun-hammer, and since this is done with each. The operating lever 26 is around a rotary hammer can be different, depending on point34 rotatably, the lower of which is how often the hammer was used, this 15 lever part is located in front of an electromagnet 36, to the changes in the respective travel time The connections of the winding 38 can optionally be hammered. a signal S can be supplied.

Another disadvantage arises from the fact that the front and rear parts 16 and 18 of the ham-

The damping properties cannot be adjusted, and they also contain two levels through which once the elastic material is attached 20 speaking surface of the stem 20 protruding is. If z. B. a hammer are exchanged surfaces 40 and 42, respectively.

must, then the differences between the on one side of the print hammer 10 is a hufalten and the new hammer a change in the iron-shaped electromagnet 44 with the two pole damping strength require. If an elastic surface 46 and 48 is arranged. The arrangement of the damping material used behind each stop, 25 pole face 46, is such that when the pressure decreases then it such a change can only be found with difficulty in its rest position, opposite the leads to be. Surface 40 of the front part is arranged so that

There are also electromagnetic damping that therebetween an air gap 47 of substantially facilities for the hammers known, but the same width. The pole face 48 is counter-complicated and complex in construction and therefore 30 above the surface 42 of the rear hammer part are expensive to manufacture and not the high ones arranged so that in between a more uniform There are requirements for an operationally safe working air gap 49, which is essentially the same to fill. The width of the gap is 47. About the connections of the

The object of the invention is therefore to provide a damping winding 53 of the magnet 44 as a signal source 51 Creation arrangement for print hammer, the 35 connected and optionally generates a current avoids the disadvantages listed. with damped waveform 55 (see FIG. 1 A). The to-

According to the invention, a pressure hammer-guided signal can be used in terms of amplitude and aggregate can be changed to the desired damper-damper with a duration designed as a magnet proposed to generate its power flow via reducing properties, at least one projection of the print hammer extends 40 In the preferred embodiment of the invention and which is arranged so that the path of the magnet is essentially repeated in FIG. IA dartic Lines of force in the rest position of the hammer on the set arrangement 132 times, with the respective shortest is. Print hammers 10 side by side in a row fishing a preferred embodiment has which are arranged. Each print hammer is made with the help of Wave form of the current for the winding of the damper 45 is held by two leaf springs, and exists between them fermagneten take the form of a damped oscillation. enough space for the hammer to move. The magnet arrangement is normally only during a single magnet 44 is preferably used Paper feed interval excitable and not that, which extends over the entire width of the print hammer the actual printing process. row extends so that successive printing

Below are different sections to better explain the 50 hammer Embodiments of the invention are located in the same pole faces 46 and 48. The trash drives; the description refers to the two-part 32 can either carry a single hammer, joined figures. or a modular arrangement can be used

Fig. IA shows an elongated print in which a carrier carries more than one hammer, hammer 10, opposite to a type roller 12 55 The actuating lever 26 for successive is arranged, which is designed in such a way that it can be used alternately with pressure hammer from above constant speed in the direction of the arrow down and from bottom to top (in the rotates. On the outer surface of the type roller are Fig. 1 A) extending, whereby the increased for each electro Type 14 provided, the necessary space is created in continuous magnets 36. Rows are arranged, with each row as many as 60. The hammer is in the cowl position, which is in contains the same types as hammers at the printing stage. F i g. 1A, it touches the convex tion are. In a preferred embodiment surface 24 the operating lever 26, which in turn on For example, a printing station 132 printing hammers in one of the fixed stop 28 rests. The leaf line included side by side. springs 30 are in the rest position either the print hammer 10 has a front part 16 65 perpendicular to the carrier 32 or are slightly forward and a rear part 18 inclined by an intermediate, i.e. H. on the type roller 12 to the see arranged shaft 20 are connected. All print hammer 10 the required preload for Parts of the print hammer have the same strength. to give the rest position. The distance of the concave

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Impact surface 22 of the hammer from the raised arrangement. The attenuation signal is only

Type 14 in the rest position depends on the number rend of the paper feed cycle. It is

the penetration, for which stand with the interposed, so with the forward movement of the hammer

If carbon paper and the ribbon have enough space during the print cycle no overlap, must be present. 5 Of course, the damping sign],

If during the printing cycle of the winding 38, immediately after the completion of the previous

one of the electromagnets 36 is given a signal S supplied to the pressure cycle, only damping

then the appropriate actuation of such hammers will still be available at that point

lever 26 tightened and rotates to swing its pin 34. The hammer that was after an earlier time front. The forward movement of the actuation point of the print cycle has been actuated are normal

lever 26, which with the convex impact surface 24 times at the end of the printing cycle already in their

of the hammer 10 has contact when it has returned to its rest position.

is in its rest position, causes the Ham- From the drawings it can be seen that the actuating

mer 10 is moved forward quickly (see Fig. 1B). transmission lever 26 in the vicinity of the magnetic flux path on-In In a preferred embodiment, the movement is ordered, but preferably, for better handling

movement of the operating lever 26 is limited, so that the ability to drive is not included in this. To the-

the print hammer 10 by its own swing - accordingly, the lever 26 can be made of stainless steel

force forward, in the direction of the type roller, its permeability compared to the

away and the interposed paper and hammer 10, which are made of hardened steel Ribbon at high speed against the 20 can, is low. The end part of the actuation

Type roller presses. After the rebound from the Tyheis 26, which is connected to the hammer striking surface 24 in

pen roller returns the hammer to its rest position- if it is touched, can further reduce the

back, being specially treated by the leaf springs 30 supported permeability,

will. Through this backward movement, the FIG. 2 becomes another embodiment Hammer 10 also shows the actuating lever 26 again at 25. In this embodiment, an annular

the stop 28 in contact. Magnet 58 used, the pole faces 54 and 56

The speed at which the hammer is placed in its at right angles to each other. As Returning to the rest position is about half of that shown in FIG. 1 embodiment shown extrek-forward movement. The hammer rebound from actuating the pole faces 54 and 56 all over levers and the subsequent vibrations 30 row of juxtaposed pressure hammers as soon as possible during the paper mer 10. In this embodiment, each pressure feed cycle is be damped to hammer the hammer provided with a lug 52 made of a material for printing during the next high permeability printing cycle, which is preparing in the dormant. For this purpose, after the hammer has ended (Fig. 2 A) between the poles each print cycle of the magnet winding 53 the 35 areas 54 and 56 is located. Between the two right-attenuation signal supplied, which in Fig. IA at an angle to each other surfaces 57, 59 of the attenuated waveform 55 shown. This damping approach and the corresponding pole faces 54 Fungssignal generates a magnetic flux through the and 56 result in two equal air gaps 60 and 62. Magnet 44, the hammer 10 and the two air- Fig. 2B shows the hammer in its front column 47 and 49. The 40 position bridging the column. The pole face 54 is only here Magnetic flux lines are shown in dashed lines in the figures as opposed to part of the attachment surface 57. Dem lines shown. When the hammer is in its proper position, part of the flow through the pole face 54 Rest position is (Fig. 1 A), these are lines and flowing magnetic flux on the surface 59 and This means that the entire magnetic flux path is also directed to the poles with a further part of the magnetic flux. 45 area 56. The width of the gap 60 is therefore un-

While the length of the magnetic flux path increases uniformly. Similarly is also

Gap 49 also in the front position of the hammer the gap 62 in the front position of the hammer

(F i g. 1 B) remains the same, the gap 47, mers 10 increases larger than when the hammer is in its

and the magnetic flux path in gap 47 is essentially the rest position.

larger than when the hammer is at rest. The 5 ° A major advantage of the in F i g. 2 illustrated

Length of the entire magnetic flux path increases th arrangement is that the print hammer

so, and a force is generated to safely remove the urinary and operating levers from the magnetic flux

to bring it back to its rest position. This path can be kept out so that this

Hold is based on the principle of the least only the magnet 58, the air gaps 60 and 62

magnetic resistance, after which the magnetic flux 55 and the approach 52 comprises. As for the latter, not

tends to look for the shortest route. Since the same requirements apply as for the hammers

The magnetic flux path in the gap 47 then has its smallest mer, it can be made of a material of high permeability

Length when the hammer is in its rest position, which increases the sensitivity

ment is, the magnetic flux exerts against a further and a higher damping effect is achieved.

The returning hammer bounces off the 60.

Hammer operating lever 26 used a restraining force voltage under other operating conditions

the end. and depending on the special operating conditions

It is noted that the timing and strength of the genes are changed. So can the attenuation an-attenuation About the order fed to the winding 53 z. B. used in chain printers, Attenuation signal can be controlled. The maxi- 65 with which also a quick dampening of the hammer marks Amplitude of the supplied signal, which is about vibration required. The training of the Can be 3 to 4 amps, depends on the type of hammer 10 can be changed, provided desired damping requirements of the entire that a projection is provided that over a

changeable gap and by means of a magnetic flux with is chained to a magnetic pole. The hammer itself does not need to be stored on leaf springs, like it is shown, but he can move in guide means with resilient means him in his Pre-tension the rest position. The hammer can be operated in different ways, directly or as described, indirectly or with the aid of various force-exerting means.

The described damping arrangement enables a rapid printer hammer in its rest position to come to rest within a time interval of 3 milliseconds compared to 20 milliseconds, which are required in known devices. Under these conditions, the ricochet is the Hammers no longer have a restriction on increasing the printing speed, as is the case with known ones Damping devices was still the case. In addition to the simple design, the one described offers Arrangement still a controllable damping, which the requirements of different operating conditions can be customized. The use of only one magnet that extends over the entire row of hammers extends enables implementation at a relatively low cost.

Claims (9)

Patent claims: 1. Print hammer unit for high-speed printers, in which the individual print hammer is operated by spring force held with bias against their stop movement in their rest position and optionally can be driven by actuating levers against the paper to be printed, with dampers for suppression the vibrations occurring on return of the hammer are provided, d a through characterized in that the damper is designed as a magnet (44) whose power flow runs over at least one projection (16,18,52) of the printing hammer (10) and which is arranged in this way is that the path of the magnetic lines of force in the rest position of the hammer (10) is shortest is. 2. Unit according to claim 1, characterized in that the waveform of the current for the winding of the damper magnet is in the form of a damped oscillation (55). 3. Unit according to claim 2 or 3, characterized in that the hammer (10) during of the printing process approximately at right angles to the magnetic flux (49 or 60) of at least one pole (48 or 54) of the electromagnet (44 or 58) is deflected. 4. Unit according to claim 1 to 3, characterized in that the hammer at the end of the Projection (16, 52) on the side remote from the pressure disc (12) has a narrowing Part (20) that progressively moves under the pole (46 or 54) as the hammer moves moved towards the thrust washer (12). 5. Unit according to claim 1 to 4, characterized in that the electromagnet (44) in is C-shaped in a known manner and thus has two poles (46, 48), which are next to the hammer (10), and that the hammer has two projections (40, 42) opposite the poles (46, 48), when the hammer is at rest. 6. Unit according to claim 1 to 5, characterized in that the two projections (40, 42) are connected to one another by a narrow neck (20). 7. Unit according to claim 1 to 6, characterized in that between the hammer (10) and a rest stop (28) which is arranged at one end of a centrally mounted arm (26) and that next to the other end of the arm, an electromagnet (36) is provided, which at his Excitation swings the arm around its bearing point (34) and thus actuates the hammer (10), wherein the hammer (10) and the arm (26) are made of magnetic material and the magnetic Permeability of the arm (26) compared to that of the hammer (10) is low. 8. Unit according to one of claims 1 to 7, characterized in that in the windings (53) of the electromagnets (44 or 58) flowing currents (55) for each hammer (10) optionally are adjustable in order to achieve an optimal damping of the backward movement of the hammer. 9. Unit according to one of claims 1 to 8, characterized in that all hammers (10) a single electromagnet (44) with a single winding (53) is jointly assigned for damping is and that the pole face (or pole faces) over the entire length of a hammer row are sufficient. Considered publications:
German utility model No. 1 843 638;
French Patent No. 1212 331;
British Patent No. 859,914;
U.S. Patent Nos. 3,049,990, 3,087,421. 1 sheet of drawings 809 620/526 9.68 © Bundesdruclcerei Berlin