EP0028539B1 - Druckhammeranordnung - Google Patents

Druckhammeranordnung Download PDF

Info

Publication number
EP0028539B1
EP0028539B1 EP19800303951 EP80303951A EP0028539B1 EP 0028539 B1 EP0028539 B1 EP 0028539B1 EP 19800303951 EP19800303951 EP 19800303951 EP 80303951 A EP80303951 A EP 80303951A EP 0028539 B1 EP0028539 B1 EP 0028539B1
Authority
EP
European Patent Office
Prior art keywords
print
hammer
plunger
impact
platen
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
EP19800303951
Other languages
English (en)
French (fr)
Other versions
EP0028539A3 (en
EP0028539A2 (de
Inventor
Andrew Gabor
Richard G. Crystal
Enrique J. Klein
Michiel Frankhuizen
William D. Rempel
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Xerox Corp
Original Assignee
Xerox Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from US06/091,605 external-priority patent/US4327639A/en
Priority claimed from US06/091,657 external-priority patent/US4324497A/en
Application filed by Xerox Corp filed Critical Xerox Corp
Publication of EP0028539A2 publication Critical patent/EP0028539A2/de
Publication of EP0028539A3 publication Critical patent/EP0028539A3/en
Application granted granted Critical
Publication of EP0028539B1 publication Critical patent/EP0028539B1/de
Expired legal-status Critical Current

Links

Images

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
    • B41J9/00—Hammer-impression mechanisms
    • B41J9/02—Hammers; Arrangements thereof
    • B41J9/04—Hammers; Arrangements thereof of single hammers, e.g. travelling along printing line

Definitions

  • This invention relates to a print hammer assembly employing an electromagnetic actuator to drive a hammer element against a print platen or against an adjacent print element, to thereby cause said print element to strike an adjacent platen.
  • the invention is more particularly concerned with a print hammer assembly of the kind which comprises a support structure pivotally mounted about an axis adjacent a print platen, a magnetically attractable plunger mounted by a rigid support means on said support structure, a print hammer mounted by leaf spring means, on said support structure, the plunger and the hammer being spaced apart angularly about said axis, and an actuator capable of being energised to create a magnetic field so as to attract said plunger and thereby rotate said support structure about the pivot axis and so cause the hammer to make an impact with the print platen or with an interposed print element.
  • a print hammer assembly of this kind is described in US-A-3 968 744, and consists of a light weight moulded hammer having a rigid support member which carries a magnetically attractable armature and which is formed integrally with a pair of flexure members.
  • the flexure members carry an impact tip which constitutes the hammer.
  • the armature On energisation of a solenoid, the armature is attracted directly to one of its poles, the armature being prevented from contacting the pole only by virtue of an intervening shim.
  • the flexure members carry the impact tip in free flight towards the print position, and a back-up portion of the support member adjacent one of the flexures carries a shock-absorbing pad to dampen the rebound of the impact tip and to prevent a return rebound.
  • a disadvantage of such print hammer assemblies is that audible noise attributed to impacts is relatively high. More specifically, not only does the hammer element impact the print element against an adjacent platen, but the armature impacts the pole piece of the electromagnetic actuator, or the support arm impacts the stop. Since the armature and pole pieces of the actuator, or the support arm and stop, are generally metallic, it will be appreciated that the noise level is significantly increased over that attributable solely to impact of the hammer element against the print element.
  • Printers where the dwell time of a print element forcing a marking medium against an adjacent platen due to the force of a hammmer element against the print element can be increased by increasing the mass of the hammer element.
  • An increase in dwell time increases the quantity of marking material released and improves the quality of the printing.
  • this arrangement has the disadvantage of increasing the flight time of the hammer element, thereby correspondingly decreasing the maximum printing speed.
  • a further disadvantage is that of increasing the kinetic energy of impact, which may result in decreased life of the print elements, or require that the print elements be fabricated of a more durable, and thus more costly, material.
  • US-A-3 547 028 describes an apparatus in which the striking member of a printer is a harmonically vibratable reed excited by an electromagnet. This reed likewise impacts a pole piece during its vibration.
  • the present invention is intended to provide a print hammer assembly which is quieter in operation than known assemblies, and which gives a longer dwell time of the print hammer, but which overcomes the above described disadvantages of known assemblies.
  • the invention accordingly provides a print hammmer assembly of the kind specified which is characterised in that the actuator is located alongside a space in which said magnetic field is created and through which said plunger is free to travel on energisation of the actuator, without contacting the pole pieces thereof so that further rotational movement of the support structure after said impact is restrained only by the leaf spring means, and that the masses of the hammer and plunger are selected in relation to the properties of the leaf spring means so as to produce more than one of said impacts for each energisation of the actuator.
  • the relative distance between the plunger and each of the magnetizable members is not critical, since the total force will be substantially the same regardless of whether or not these two distances differ. More specifically, the driving force is related to the addition of the two gap distances on either side of the plunger and the geometry of the plunger. If the distance between plunger and each of the magnetizable members is different, the driving force will essentially be the same as when the plunger is centered, since the sum of the two distances will always be the same.
  • the driving force is related to the geometry of the total gap area swept, as opposed to being inversely proportional to the square of an ever decreasing gap size, as in the arrangement where an armature is attracted directly to a pole piece, much less energy need be expended to achieve the requisite print quality with either system. More specifically, the significant amount of electrical power required to actuate the armature of prior art devices is not required. A substantially lower level of power can be used, thereby conserving energy. Additionally, the geometry of the sweeping gap approach of this invention permits the hammer element to experience maximum acceleration early in the hammer stroke, thus cutting down the overall flight time.
  • the mass of the hammer element is not increased to effect an increased dwell time. Rather, a dual mass system (the plunger and the hammer element) is employed, wherein the means for coupling together the two masses includes means cooperating with the first mass for increasing the dwell time. There is thus no decrease in the flight time of the hammer element and increase in kinetic energy of impact.
  • the plunger and hammer element By arranging the plunger and hammer element such that the hammer element will strike a print element against a platen while the plunger continues to travel in the same direction, the resiliency of the spring assembly will retain the hammer element against the print element and platen for a longer period of time than had the hammer element been allowed to immediately rebound, as in the case of ballistic hammer assemblies.
  • the increased dwell time also enables the peak impact force to be reduced without loss in print quality, thereby enabling lower cost print element, such as plastic print elements, to be employed.
  • the impacts can be achieved at lower peak force levels, thereby enabling the use of lower cost (e.g., thermo-plastic) print elements and the like, while maintaining high print quality and normal printing speeds.
  • lower cost e.g., thermo-plastic
  • the provision of multi-impact per single energization also contributes to a reduction in noise, since the peak impact forces are less. Further, the two impacts occur relatively rapidly, thereby reducing or avoiding settling of the print element and incumbent in accuracy problems. Still further, there is no transverse movement of the print element between multiple strikes per single energization which could cause "ghosting" and the like, due to the control achieved by impacting more than one per single energization.
  • the multi-impact approach of this invention is less susceptible to voids of the marking medium in the printed character, i.e., the second impact fills in at least some of the voids that may have been left in the printed character following the first impact. This advantage provides another basis for using lower cost print elements.
  • the leaf spring means comprises a pair of non-parallel leaf springs.
  • the effect of altering the location of maximum impact force following initial impact may be amplified over the effect achieved by using parallel leaf springs.
  • This is accomplished due to the trapezoidal configuration of the offset leaf springs as connected to the hammer element at one end and to support structure at the other end.
  • the trapezoidal configuration imparts a more pronounced shift in maximum impact force location following initial impact than would a strict parallelogram formed by parallel leaf springs. Consequently, more pronounced misalignments of the platen axis may be compensated for through the use of offset leaf springs in the arrangement above-described.
  • a print hammer assembly 10 in accordance with the present invention is shown in Figure 1 mounted to a carriage assembly 12, which may be of the general type disclosed in the aforementioned U.S. Patent No. 4,037,532.
  • the carriage assembly 12 is thus adapted to transport not only the hammer assembly 10, but also a rotatable print wheel 14 of the "daisy-wheel” type and a ribbon cartridge (not shown) to selected positions along a predefined linear path parallel to the axis of rotation of a cylindrical support platen 16 mounted adajacent the carriage assembly 12.
  • the carriage assembly 12 comprises an outer carriage frame 18 and an inner carriage frame 20.
  • the inner carriage frame 20 may be pivotably mounted to the outer carriage frame 18 by means of a suitable pivot bolt 22 extending through the side walls of the frames 18 and 20.
  • the outer carriage frame 18 is preferably fixed in position in a manner to be described below, and the inner carriage frame 20 is pivotable about bolt 22 relative to frame 18.
  • Suitable means are provided for locking the inner carriage frame 20 in each of two positions, i.e., a print wheel loaded position (shown in Figure 1) and a print wheel loading position (not shown), wherein the frame 20 would be pivoted clockwise relative to the position shown in Figure 1.
  • the outer carriage frame 18 has a pair of aligned openings 24 formed in the respective side walls of frame 18 adjacent the front end of the carriage assembly 12, and a pair of aligned recesses 26 formed in such respective side walls adjacent the rear end of the carriage assembly 12.
  • the openings 24 and recesses 26 are each adapted to receive in locked relation a linear bearing assembly which may be of the type disclosed in U.S. Patent No. 3,985,404.
  • the pair of linear bearing assemblies are adapted to receive a corresponding pair of guide rails mounted parallel to the axis of the platen 16 and along which the carriage assembly 12 rides.
  • a print wheel motor 28 is mounted by suitable means (not shown) to the inner carriage frame 20.
  • the motor 28 controls the speed and direction of rotation of the print wheel 14 in order to bring a desired print or character element 30 thereon to a stationary printing position in alignment with the platen 16 and a hammer element 32 included in the hammer assembly 10.
  • the motor 28 has a shaft 34 projecting forwardly of the inner carriage frame 20.
  • a hub portion 36 forms part of the shaft 34 and is adapted to be received in the central opening (not shown) of the print wheel 14.
  • An exemplary print wheel is generally disclosed in U.S. Patent No. 3,954,163.
  • the hammmer assembly 10 includes a support structure or frame 38 which defines a first mass and is desirably of generally trapezoidal shape with a pair of inwardly projecting finger portions 40 and 42 coupled at their upper ends by a bridge portion 44. Affixed to the outer surface of the bridge 44, or formed as an integral part thereof, is a plunger 46, which is desirably of a ferromagnetic material, such as soft iron.
  • the finger portions 40 and 42 are coupled at their lower ends by generally U-shaped attachment portion 48 having opposing side wall flange portions 50 and 52.
  • the flange portions 50 and 52 include respective aligned openings 51 and 54 formed therein.
  • the openings 51 and 54 are adapted to accommodate a pivot rod (not shown) that projects through both openings 51 and 54 and a corresponding pair of openings 56 ( Figure 1) in the side walls of the inner carriage frame 20. In this manner, the support frame 38 is pivotably mounted to the inner carriage frame 20.
  • the side wall flange portions 52 and 50 of the attachment portion 48 further include respective aligned openings 53 and 55 formed therein. Each such opening is adapted to retain an end of one of a pair of springs 57 (only one shown in Figure 1).
  • the other ends of the springs 57 are mounted to the inner frame 20.
  • the springs 57 cooperate to bias the support frame 38 in a clockwise direction (as shown in Figure 1) such that the supportframe 38 is normally biased against a stop (not shown) also mounted to the inner frame 20.
  • the support frame 38 may be pivoted counterclockwise about the pivot rod through openings 56 against the bias of springs 57 upon energization of an electromagnetic actuator 59 forming part of the hammer assembly 10 in a manner to be described below.
  • the hammer assembly 10 further includes the hammer element 32, which forms part of a second mass 58 that is coupled to the support frame 38 by at least one, and preferably two, leaf springs 60 and 62.
  • the hammer element 32 preferably has a grooved impacting surface 33 that is matable with a corresponding wedge (not shown) formed on the rear surface of each character element 30. In this manner, minor misalignments between the hammer element and the selected character element can be corrected.
  • the second mass 58 includes three mounting blocks 64, 66 and 68, which are preferably of identical material, and a counter-balanced weight 69 affixed to the mounting block 68.
  • the hammer element 32 projects forwardly from the center of a side surface of the block 64.
  • the leaf springs 60 and 62 are substantially identical and normally planar, and are spaced apart in parallel relationship.
  • the mounting blocks 64, 66 and 68 are substantially identical in dimensions, except for the hammer element 32 projecting from the mounting block 64.
  • the upper end of the spring 60 is disposed between the mounting blocks 66 and 68, while the upper end of the spring 62 is disposed between the mounting blocks 64 and 66.
  • the lower ends of the springs 60 and 62 are mounted on either side of the attachment portion 48 substantially centered between the side wall flange portions 52 and 54.
  • a pair of mounting blocks 70 and 72 are attached to the lower ends of the springs 60 and 62 and hold them by suitable fastening means (not shown) against the attachment portion 48 of the support frame 38.
  • the hammer assembly 10 further includes the electromagnetic actuator or solenoid 59.
  • the solenoid 59 has a C-shaped yoke 74 with a pair of depending legs 76 and 78 each containing an electrically conductive coil 80 and 82, respectively, mounted thereon.
  • the space 84 between the portion of each leg 76 and 78 projecting downwardly from the respective coil 80 and 82 mounted thereon is of sufficient dimensions to accommodate the plunger 46 therein, as shown in Figure 3. With the plunger 46 positioned within the space 84, gaps 86 and 88 are defined between the sides of the plunger 46 and the adjacent legs 76 and 78, respectively.
  • the gaps 86 and 88 need not be identical in dimensions, thereby reducing the necessity of critical adjustments with respect thereto. Additionally, the spacing 85 between the upper surface of the plunger 46 and the lower surfaces of the coils 80 and 82 is not critical. The reasons for these non-critical relationships will be described in more detail below.
  • the solenoid 59 is mounted to the inner carriage frame 20 by affixing, through a pair of screws 90, the legs 76 and 78 to a selonoid frame 92, which is itself affixed by means (not shown) to the side walls of the inner carriage frame 20.
  • the support frame 38 and solenoid 59 are normally positioned relative to one another such that a front surface 94 of the plunger 46 normally liesJust to the rear of the legs 76 and 78 in alignment with the space 84.
  • the plunger 46 begins to move through the space 84, thereby causing the support frame 38 to pivot about rod 56 and thus hammer element 32 to move toward the platen 16.
  • the hammer element 32 will engage the rear surface of the print element 30 and begin forcing it toward the platen.
  • the hammer element 32 will force the print element 30 and an interposed marking medium and record medium, such as an inked ribbon and paper (both not shown), against the platen 16.
  • the hammer element 32, and thus print element 30, will each experience a first rebound a predetermined distance from the platen 16.
  • the rebound distance of the hammer element 32 is determined by the siffness and length of the springs 60 and 62, as well as by the ratio of the two masses separated by the springs 60 and 62, and the force-of impact, whereas the rebound of the print element 30 is determined by the resiliency of the print wheel spoke bearing the print element 30 and force of the impact.
  • the hammer element 32 will rebound a second time, mainly due to the energy released after impact by the viscoelastic material of platen 16. Additionally, the plunger 46 and thus support frame 38 will continue their retract due to the bias of the springs 57 and prior deenergization of the solenoid 59. It must be made clear that the solenoid 59 can be deenergized at any point in time following initial energization, provided the forward driving force imparted to the hammer element 32 is sufficient to achieve the desired multi-impact and consequent desired release of marking material.
  • the overall dwell time of the print element 30 against the platen 16 may be increased by continuously energizing the solenoid 59, including for a finite time after the second impact, thereby further increasing the total quantity of marking material (e.g., ink) released.
  • the dwell time of the first impact may also be increased by stiffening the springs 60 and 62 or increasing the mass of the hammer element 32 and/or the plunger 46.
  • two distinct impacts are preferred. It will still be appreciated, however that the overall dwell time is increased by two or more impacts over that which would normally be achieved by a single impact of the prior art hammer assembly disclosed in U.S. Patent No. 4,037,532, since the hammer element of that assembly would immediately rebound following impact.
  • the overall impact time during which marking material is released is obviously greater during a multiple impact condition than a single impact with immediate rebound thereof.
  • Oscilloscope traces showing the relationships among travel of the hammer element 32, level of current flow through the coils 80 and 82, level of impact force by the hammer element 32, and time, are shown in Figures 9 and 10, for two different profiles of coil current.
  • Hammer element travel was measured with an optoelectric device in which hammer element movement is proportional to output voltage, as shown in Figures 9 and 10.
  • Current flow was measured with a current probe measuring current through the solenoid coils 80 and 82.
  • impact force was measured by piezo-electric force transducer positioned beneath the platen covering.
  • Yet another feature of the hammer assembly 10 is occasioned by the parallelogram defined by the pair of parallel springs 60 and 62 connected at one end to the mass 58, which includes the hammer element 32, and at its other end to the attachment portion 48 of the support frame 38, which defines an additional mass.
  • the parallelogram defined by the pair of parallel springs 60 and 62 connected at one end to the mass 58, which includes the hammer element 32, and at its other end to the attachment portion 48 of the support frame 38, which defines an additional mass.
  • a trapezoidal configuration is thus defined by the springs 60' and 62', mounting blocks 64', 66' and 68', and the attachment portion 48 of the support frame 38 to which the lower ends of the springs 60' and 62' are mounted by suitable interposed mounting blocks (not shown).
  • This trapezoidal shape has been found to amplify the counterclockwise movement, or "heel-toe" effect.
  • the heel-toe effect reduces the need for critical adjustments of the platen 16 to insure that its axis of rotation is completely parallel to the rails (not shown) on which the carriage assembly 12 rides. For example, if the platen axis is skewed relative to the rails in a vertical direction, the top half of characters might not be printed at one end of the paper while the bottom half might be deleted from the other end.
  • By striking each print element twice, once low and once high, minor misalignments in a vertical direction will be compensated for in the embodiment of Figures 1-6, and more major misalignments will be compensated for in the embodiment of Figures 7 and 8.

Landscapes

  • Impact Printers (AREA)

Claims (2)

1. Eine Druckhammeranordnung mit einer um eine Achse nahe einer Druckwalze (16) schwenkbar gelagerten Halterungsanordnung (38), mit einem magnetisch anziehbaren Stempel (46), der mittels einer starren Stützeinrichtung (42) an der genannten Halterungsanordnung angebracht ist, mit einem mittels einer Blattfedereinrichtung (60, 62) an der genannten Halterungsanordnung (38) angebrachten Druckhammer (32), wobei der Stempel (46) und der Hammer (32) mit gegenseitigem Abstand im Winkel um die genannte Achse angeordnet sind, und mit einer Antriebseinrichtung (59), die geeignet ist, zur Erzeugung eines Magnetfeldes erregt zu werden, um den genannten Stempel (46) anzuziehen und dabei die genannte Halterungsanordnung um die Schwenkachse zu drehen und so zu bewirken, daß der Hammer (32) einen Schlag auf die Druckwalze (16) oder auf ein dazwischen angeordnetes Druckelement (30) ausübt, dadurch gekennziechnet, daß die Antriebseinrichtung (59) entlang einem Raum (84) angeordnet ist, in welchem das genannte Magnetfeld erzeugt wird und durch welchen der genannte Stempel (46) sich bei Erregung der Antriebseinrichtung, ohne deren Polstücke zu berühren, frei hindurchbewegt, so daß eine weitere Drehbewegung der Halterungsanordnung (38) nach dem genannten Schlag lediglich durch die Blattfedereinrichtung (60, 62) verzögert wird, und daß die Massen des Hammers (32) und des Stempels (46) im Verhältnis zu den Eigenschaften der Blattfedereinrichtung ausgewählt sind, um mehr als einen der genannten Schläge bei jeder Erregung der Antriebseinrichtung (59) zu bewirken.
2. Die Druckhammeranordnung nach Anspruch 1, in welcher die genannte Blattfedereinrichtung ein Paar nicht-paralleler Blattfedern (60', 62') umfaßt.
EP19800303951 1979-11-05 1980-11-05 Druckhammeranordnung Expired EP0028539B1 (de)

Applications Claiming Priority (10)

Application Number Priority Date Filing Date Title
US9165879A 1979-11-05 1979-11-05
US9164579A 1979-11-05 1979-11-05
US06/091,605 US4327639A (en) 1979-11-05 1979-11-05 Print hammer assembly with multi-location impacts
US91645 1979-11-05
US91605 1979-11-05
US06/091,657 US4324497A (en) 1979-11-05 1979-11-05 Print hammer assembly with amplified multi-location impacts
US9164679A 1979-12-19 1979-12-19
US91646 1979-12-19
US91658 1987-09-01
US91657 1987-09-01

Publications (3)

Publication Number Publication Date
EP0028539A2 EP0028539A2 (de) 1981-05-13
EP0028539A3 EP0028539A3 (en) 1982-05-26
EP0028539B1 true EP0028539B1 (de) 1986-04-09

Family

ID=27536610

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19800303951 Expired EP0028539B1 (de) 1979-11-05 1980-11-05 Druckhammeranordnung

Country Status (2)

Country Link
EP (1) EP0028539B1 (de)
DE (1) DE3071538D1 (de)

Families Citing this family (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6061277A (ja) * 1983-09-14 1985-04-09 レックスマーク・インターナショナル・インコーポレーテッド 印刷装置
US4525086A (en) * 1983-09-14 1985-06-25 International Business Machines Corporation Solenoid actuated pivotal printer hammer mechanism
US4678355A (en) * 1985-07-02 1987-07-07 Xerox Corporation Print tip contact sensor for quiet impact printer
US4681469A (en) * 1985-07-02 1987-07-21 Xerox Corporation Quiet impact printer
US4737043A (en) * 1985-07-02 1988-04-12 Xerox Corporation Impact mechanism for quiet impact printer
CA1260861A (en) * 1985-07-02 1989-09-26 John C. Dunfield Impact mechanism for quiet impact printer
US4686900A (en) * 1985-12-05 1987-08-18 Xerox Corporation Impact printer with application of oblique print force
US5199804A (en) * 1991-05-31 1993-04-06 Smith Corona Corporation Quiet impact printer mechanism
US5174671A (en) * 1991-10-28 1992-12-29 Smith Corona Corporation Printing mechanism with print hammer having noise dampener

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1572747A (de) * 1967-06-28 1969-06-27
FR2010623A1 (de) * 1968-06-11 1970-02-20 Sits Soc It Telecom Siemens

Also Published As

Publication number Publication date
EP0028539A3 (en) 1982-05-26
EP0028539A2 (de) 1981-05-13
DE3071538D1 (en) 1986-05-15

Similar Documents

Publication Publication Date Title
US3504623A (en) Hammer arrangement for high-speed printers
US3982622A (en) Actuator mechanisms for wire matrix printers
US4674896A (en) Printing mechanism for an impact matrix printer
EP0028539B1 (de) Druckhammeranordnung
US3670647A (en) Method of damping rebound of print hammer
US3726213A (en) Print hammer with high repetition rate
EP0065620B1 (de) Sich selbst zurückstellende Schwingvorrichtung und damit ausgestatteter Druckhammer
US4327639A (en) Print hammer assembly with multi-location impacts
US3780648A (en) High speed print hammer with dynamic damper means
US3968744A (en) Self-damping unitary print hammer for high speed printers
US4269117A (en) Electro-magnetic print hammer
US4324497A (en) Print hammer assembly with amplified multi-location impacts
US3919936A (en) High speed line printing apparatus
US3585927A (en) Pivotally mounted high performance print magnet
CA1096234A (en) Wear minimizing means for printing mechanism
US3905294A (en) High speed line printing apparatus
US4708501A (en) Electromagnetic hammer printing device including a limited action spring force
CA1211735A (en) Impact hammer
US4603985A (en) Backstop and damping apparatus for actuator
US3981236A (en) Printhead for impact printer
US5013169A (en) Print head having reduced noise and vibration characteristics
GB1563779A (en) Printing apparatus
EP0023153A1 (de) Druckhammermechanismus
JPH0123812Y2 (de)
US4498388A (en) Print hammer mechanism having intermediate pivot fulcrum

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Designated state(s): DE FR GB IT NL

17P Request for examination filed

Effective date: 19811003

PUAL Search report despatched

Free format text: ORIGINAL CODE: 0009013

AK Designated contracting states

Designated state(s): DE FR GB IT NL

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): DE FR GB IT NL

REF Corresponds to:

Ref document number: 3071538

Country of ref document: DE

Date of ref document: 19860515

ET Fr: translation filed
ITF It: translation for a ep patent filed
PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed
PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 19900905

Year of fee payment: 11

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 19900919

Year of fee payment: 11

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 19901031

Year of fee payment: 11

ITTA It: last paid annual fee
PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: NL

Payment date: 19901130

Year of fee payment: 11

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Effective date: 19911105

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: NL

Effective date: 19920601

GBPC Gb: european patent ceased through non-payment of renewal fee
NLV4 Nl: lapsed or anulled due to non-payment of the annual fee
PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Effective date: 19920731

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Effective date: 19920801

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST