Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
  • B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
  • B41J2/22—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by selective application of impact or pressure on a printing material or impression-transfer material
  • B41J2/23—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by selective application of impact or pressure on a printing material or impression-transfer material using print wires
  • B41J2/235—Print head assemblies
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
  • B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
  • B41J2/22—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by selective application of impact or pressure on a printing material or impression-transfer material
  • B41J2/23—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by selective application of impact or pressure on a printing material or impression-transfer material using print wires
  • B41J2/27—Actuators for print wires
  • B41J2/275—Actuators for print wires of clapper type
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
  • B41J9/00—Hammer-impression mechanisms
  • B41J9/16—Means for cocking or resetting hammers
  • B41J9/24—Electromagnetic means

Definitions

• the invention relates to a needle printhead with ring-shaped hinged armature magnets, the armatures are each connected to a pressure needle, the guides by needle shifted approximately centrally to the magnet arrangement! I are guided and on their anchors counteracting the retraction direction of the hinged armature acting restoring means are arranged, which spend the armature in the de-energized state of the hinged armature magnet against a stop, so that there is an air gap of a predetermined size between the armature and the plane surfaces of the hinged armature magnets , which is determined by an anchor thickness and a spacer, in which the anchors are pivotally mounted and on the end faces of a stop body having a flat anchor stop surface is attached.
• DE 22 01 049 R2 describes a wire dot print head whose armature is made of a ferromagnetic part is produced by turning and milling.
• the anchor ends are in one plane; however, these are only leveled by turning and not by lapping, since a protruding retaining edge with a bearing groove is provided for the anchor. that does not allow any other processing. Since the armature rests on the middle yoke, the air gap results from the distance between the cover contact surface and the armature end face, the thickness of the stop and the thickness of the armature. It is therefore dependent on one another, inter alia, on the rotational accuracy of the end face and the support surface.
• a line printer folding armature magnet with an electromagnetic return magnet is known, the armature of which is designed as an angle lever, one leg of which carries the print hammer and the other leg of which is the effective armature.
• This is widened at the end, so that the pole faces of the magnets assigned on both sides are at an angle to one another, which leads to a high outlay on installation.
• the anchor mass is a multiple of one of the magnetically effective areas, so that the working speed is reduced compared to a simple magnet.
• the yokes of the hinged armature magnets are fastened in segment-shaped recesses of a metal body with potting compound and the pole faces lie in one plane with an end face of the metal body and the spacer is arranged on this end face, which is punched out and laminated from sheets of narrow thickness tolerance is, the sheets have inwardly extending segment-shaped cutouts for receiving the armature and further cutouts are provided in the middle of the sheets for receiving he pivot bearing journal mounted in the anchor, and that on the spacer the stop body with the flat anchor stop surface is arranged so that the air gap width is determined only by the anchor thickness and a thickness of the holder.
• the spacer is made from stamped and layered sheets, preferably from three sheets. In this case, enlarged cutouts are preferably punched into the middle of the layered sheets, which serve to receive a pivot bearing pin of the armature.
• the hinged armature magnets are expediently mounted on a base plate with recesses, and the windings are then pushed on and soldered.
• the light metal body is turned out to accommodate the coils and the base plate.
• the sealing compound is introduced, and the end and pole faces are ground together, so that a defined reference surface is provided for the spacer mounting.
• the sheets of the spacer can be easily manufactured as stamped parts with a tightly tolerated sheet thickness.
• the anchors of a needle head are grasped and ground as a complete set before the bearing pins are inserted, so that only one grinding process, namely the one relevant to the anchor thickness, results in all air gap widths, which thus have practically no difference between them.
• the armature pole faces are radially tapered with respect to the pivot bearing, so that both the pole faces and the abutment surface are flattened for the purpose of high damping and a minimization of the remaining gap.
• the end face of the stop body directed towards the anchor is also ground so that the air gap and thus the anchor stroke is determined by the thickness of the spacer or the total thickness of its sheets less the anchor thickness.
• This temporal printing accuracy is all the more important the faster the character string and thus the head feed is selected, which, for example, is 200 characters per second for high-speed print heads: which corresponds to a feed rate of 50 cm / sec. Because of the exact temporal flight behavior of the needles and the resulting good typeface with high character speed has the advantage that a high-resolution typeface with, for example, 24 or 36 needles with so-called "near letter quality" can be created at high speed with a corresponding number of anchors and needles.
• a particularly advantageous embodiment enables a high working speed with a structure and simple manufacture, with the electromagnets with yokes and windings being fastened in a metal body on the spacer mirror-image to the tightening magnets as the restoring means and as the stop body on the same armature Windings can be connected to the control device, which energize these reset electromagnets only when the mirror image of the attracting electromagnet is not energized.
• the spacer is made of three stamped and layered sheets to enable a simple construction with a tightly tolerated air gap.
• enlarged cutouts are punched into the middle of the layered sheets, which serve to receive a pivot bearing pin of the armature.
• the hinged armature magnets are expediently mounted on a base plate with recesses, and the windings are then pushed on and soldered.
• the light metal body is turned out to accommodate the coils and the base plate.
• the sealing compound is introduced and the end and pole surfaces are ground together, so that a defined reference surface is provided for the spacer assembly.
• the sheets of the spacer can be easily produced as stamped parts with a closely tolerated sheet thickness.
• the anchors of a needle head are gripped and ground as a complete set before the bearing pins are inserted, so that only one grinding operation, namely the one relevant to the anchor thickness, results in all air gap widths, which thus have practically no difference between them.
• the armature pole faces are radially tapered with respect to the pivot bearing, so that both the pole faces and the abutment surface are flattened for the purpose of high damping and a minimization of the remaining gap.
• the end face of the stop body directed towards the anchor is also ground so that the air gap and thus the anchor stroke is determined by the thickness of the spacer or the total thickness of its sheets less the anchor thickness.
• This temporal accuracy of printing is all the more important the faster the character string and thus the head feed is selected, which, for example, is 200 characters per second for high-speed writing heads; which corresponds to a feed rate of 50 cm / sec.
• the head feed is selected, which, for example, is 200 characters per second for high-speed writing heads; which corresponds to a feed rate of 50 cm / sec.
• the working magnet only needs to set the armature and the needle in motion when the return magnet is deenergized and bring in the opening energy necessary for printing: there is no tensioning of the return spring, so that with the same dimensioning of the components and otherwise corresponding operating conditions, the printing speed is about 30% higher becomes.
• the arrangement of the reset magnets is preferably mirror-inverted with respect to the pull-in magnets, and their manufacture is correspondingly simple.
• the pole faces of the reset magnets serve as a stop for the armature. Since less power is required for the reset; because the impact energy of the needles, which is not used during the printing process, causes the needles to rebound; the return magnet can also be provided with shorter legs and smaller coils. To hold the returned armature, only a relatively small flow of about 2% of the suiting flow is required, since the remaining gap is very narrow, so that only very small losses occur in the windings when holding, which are known to be dependent on the flow, as is known, approximately 0.5 per thousand.
• a spring or a permanent magnet on the drive or reset side of the armature, which forms a reset or holding aid or a drive aid.
• the non-linear polar force characteristic of a reset magnet can be fully exploit without special effort that the pole faces of the permanent magnet are machined together with the pole faces of the electromagnet during the grinding process and thus a flat contact of the armature is achieved.
• a practically stress-free and torsion-free mounting of the armature with respect to the magnetic poles and the pressure needle is advantageously achieved in that the needles and / or the pivot bearing bolts are welded to the armature in situ, for which purpose preferably laser or electron beam welding is used.
• these electromagnets are advantageously excited by pulsating current before the welding and are subjected to a continuous current during the welding.
• Fig. 1 shows an enlarged axial section through a needle print head
• Fig. 2 shows an axial section on a different scale enlarged by the light metal body
• Fig. 3 shows an axial section according to the scale.
• FIG. 4 shows a section of a supervision of the
• FIG. 5 shows a section of a top view of FIG. 3
• Fig. 6 shows a section of a distance
• Fig. 1 shows an enlarged approximately 5 times a cross section through a needle printhead from the central axis (M) in the radial direction with a light metal body (1) in which a magnet yoke (3) carrying a winding (4) is cast.
• the magnet yoke (3) is inserted into a recess in the base plate (2).
• the base plate (2) which is used for the complete assembly of the tightening magnets with the windings (4) and the electrical connections, is held centrally in the recess (12) in the metal block (1).
• the segment-shaped recesses (42) in the light metal body (1) are filled with casting compound, via which the heat from the windings (4) of the magnet is dissipated.
• Cooling fins (17) are integrally formed, and the webs between the magnets serve to absorb heat.
• the casting compound is selected with high heat conduction, for which purpose metal particles are used, for example, as filling material.
• the end face (S1) of the light metal body (1) and the pole faces (S2) of the Manget yokes (3) are ground together.
• Spacers (70, 71, 71A) are arranged on the end face (S1), in which the hinged armature (5) is pivotably mounted, on the end of which extends to the center of the head, a pressure needle (51) is attached, which is arranged in web-shaped needle guides (61). are slidably mounted towards the pressure mouthpiece, not shown.
• the needle guides (61) are held in a known manner in a housing (6) which is fastened to the light metal body (1) with screws (62) in cylindrical grooves (18).
• the anchors (5) bear against the ribbed stop body (30) at the rear.
• the pivoting movement of the armature (5) is limited by the stop surface, which is just ground over with the support surface (S1A) of the stop body on the spacer (71A, 70, 71).
• the air gap (SP) of the hinged armature magnet thus results from the difference between the total thickness (D) of the spacer and the armature thickness.
• a compression spring (15) is arranged on the armature (5) as a restoring means for the armature (5).
• the springs (15) are inserted into cylindrical openings in the light metal body (1).
• FIGS. 2-7 Further details of the structure are shown in about 2 times magnification in FIGS. 2-7.
• a light metal body (1) is shown in FIG. 2 in axial cross section and in detail in FIG Face.
• the extruded profile has segment-shaped recesses (14) for 24 magnets, which are expanded by a recess (11) in the area of the windings.
• the cylindrical recesses (15Z) for the return spring or the return magnet are radially aligned with the recesses (14).
• the cooling fins (17) and orientation channels (16) are molded for pinning. Inside there is a channel for receiving the pressure wires, on which cylindrical, undercut grooves (18, 19) for fastening means are integrally formed.
• FIG. 3 and 5 show a radial section or a view of the pole faces of a base plate (2) with inserted magnetic yokes (3).
• the yokes (3) are held in cutouts (22).
• punchings (21) for the passage of the winding ends and orientation holes (26) for pinning with the orientation channels are made in the base plate (2). Connection wiring for the windings is applied to the base plate (2).
• Fig. 6 shows a section of a stamped part made of sheet metal, which serves as a central bearing plate (70) and each has segment-shaped cutouts (75) inwards for receiving the anchors. These cutouts (75) each have laterally enlarged bearing chambers (76) for receiving the pivot bearing journals (52), FIG. 8. Guide tabs (77) on both sides near the Storage chambers (76) provide a lateral anchor guide. Orientation holes (74) serve for pinning with the other sheets and the light metal body.
• Fig. 7 shows a section of the further spacer plates (71) which limit the position of the pivot bearing pin on both sides of the central bearing plate, so that largely closed bearing chambers are formed, which are advantageously filled with a permanent lubricant.
• Corresponding segment punchings (72) are made in the thin sheet for free anchor movement.
• the orientation holes (73) serve for pinning.
• Fig. 8 shows an anchor (5) in supervision. It is composed of stamped, highly permeable anchor plates (53, 53M) in layers.
• the middle anchor plate (53M) is continued to the cheapest needle connection length, so that the pressure needle (51) is welded to the end face.
• the pivot bearing journal (52) is welded into a groove (54) at the opposite end.
• the arrangement of the pin (52) in the groove (54) is shown in cross section in FIG. 1.
• the thickness of the pin (52) corresponds to the thickness of the central bearing plate with narrow tolerances.
• the anchor can also be manufactured as a sintered part instead of from sheet metal.
• An eccentric arrangement of the pivot bearing journal in the spacer and the use of only two spacer plates for it or a section of the extruded profile material as a spacer is within the scope of the expert's ability.
• a wedge-shaped configuration of the armature tapered in accordance with the armature swivel angle can be selected, which represents an optimization.
• FIG. 9 shows a supplement to the arrangement according to FIG. 1 with reset electromagnets (3A, 4A).
• a reset electromagnet (3A, 4A) acting on the armature (5) is arranged as a restoring means for the armature (5).
• a spring (15) and / or a permanent magnet (15M) can be inserted into cylindrical openings in the light metal body (1, 1A).
• the return electromagnets (3A, 4A) are each arranged symmetrically with respect to the armature (5) as a mirror image of the tightening electromagnets (3, 4), whereby they are also fixed in a base plate (2A) and cast in a light metal body (1A) .
• the pole faces of the return magnets (3A) form the stop faces (S2A).
• the two base plates (2, 2A) are closed off by cover plates (41, 41A).
• FIG. 10 shows a circuit arrangement for controlling the windings of a pull-in magnet and a return magnet (4, 4A).
• the operating voltage (U) is fed to a controllable current source (IQ), which expediently contains a pulse pause control (PP) and a freewheeling circuit (FD), the output (I) of which via controllable switches (RS, AS) to the winding (4A) of the reset magnet or the winding (4) of the control magnet is switched.
• IQ controllable current source
• PP pulse pause control
• FD freewheeling circuit
• a central pressure control (ZS) sends a control signal (A) to the switch (AS) for a given triggering time, which is determined depending on the desired stroke strength and the print material available, and the pressure control (ZS) determines the pressure at the same time Amperage of the current source (IQ) via the amperage control signal (s).
• the switch (RS) is opened via a correspondingly polarized signal (R) and the reset and holding magnet (4A) is released.
• the control signal (A) is switched off and the reset magnet current is switched on with the control signal (R).
• the energy of a winding (4, 4A) that has just been switched off is transferred to the winding that is switched on at the same time and actuates the same armature, whereby a substantial acceleration of the current build-up or breakdown is achieved.
• transfer diodes (D3, D4) mutually form a series connection of these windings, the blocking diodes (D1, D2) effecting their mutual decoupling.
• An advantageous energy-saving energization of the restoring magnets (3A, 4A) results in each case by utilizing the rebound energy of the printing needles (51) and the armature (5), in that after switching off the energization, which occurs, for example, in the event of a needle impact, there is a waiting time without energization, which lasts until for complete anchor reversal, e.g. 10 to 20 microseconds, after which the energization of the restoring magnets (3A, 4A) takes place with 1/3 to 1/10 times the tightening flow until the armature (5) hits the stop and there its rebound energy has given, which is about 3/2 to 1 times the tightening time required. The current is then switched down to the holding current of approx.
• the specified working areas relate to printing up to 5 uses and more than 5 uses.
• the appropriate values depending on the application are specified.
• the default values can be changed between two operating states in a switchable manner. If there are more than five uses, a maximum suit flow is used, and if there are fewer than five uses, the suit flow is reduced from 3/4 of this maximum value.

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• Physics & Mathematics (AREA)
• Electromagnetism (AREA)
• Impact Printers (AREA)
• Printers Or Recording Devices Using Electromagnetic And Radiation Means (AREA)

Priority Applications (2)

Applications Claiming Priority (2)

Publications (1)

Family

ID=6327069

Family Applications (1)

Country Status (7)

Families Citing this family (17)

Citations (5)

Family Cites Families (13)

• 1987
  • 1987-05-08 DE DE19873715304 patent/DE3715304A1/de active Granted
• 1988
  • 1988-05-07 KR KR1019890700009A patent/KR890701371A/ko not_active Ceased
  • 1988-05-07 DE DE90115152T patent/DE3884225D1/de not_active Expired - Fee Related
  • 1988-05-07 US US07/272,680 patent/US4988223A/en not_active Expired - Fee Related
  • 1988-05-07 WO PCT/EP1988/000393 patent/WO1988008792A1/de not_active Application Discontinuation
  • 1988-05-07 AT AT88107413T patent/ATE66868T1/de not_active IP Right Cessation
  • 1988-05-07 DE DE8888107413T patent/DE3864587D1/de not_active Expired - Lifetime
  • 1988-05-07 EP EP88903844A patent/EP0316376A1/de active Pending
  • 1988-05-07 EP EP88107413A patent/EP0293638B1/de not_active Expired - Lifetime
• 1990
  • 1990-08-04 ES ES90115152T patent/ES2043200T3/es not_active Expired - Lifetime

Patent Citations (5)

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