US3842737A - Printer - Google Patents

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Publication number
US3842737A
US3842737A US00335198A US33519873A US3842737A US 3842737 A US3842737 A US 3842737A US 00335198 A US00335198 A US 00335198A US 33519873 A US33519873 A US 33519873A US 3842737 A US3842737 A US 3842737A
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US
United States
Prior art keywords
hammer
print
rest position
magnetic circuit
permanent magnet
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 - Lifetime
Application number
US00335198A
Other languages
English (en)
Inventor
Y Gomi
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.)
Suwa Seikosha KK
Epson Corp
Original Assignee
Suwa Seikosha KK
Epson 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 JP1923472A external-priority patent/JPS5227567B2/ja
Priority claimed from JP3207172A external-priority patent/JPS539130B2/ja
Application filed by Suwa Seikosha KK, Epson Corp filed Critical Suwa Seikosha KK
Application granted granted Critical
Publication of US3842737A publication Critical patent/US3842737A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • 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
    • B41J9/26—Means for operating hammers to effect impression
    • B41J9/36—Means for operating hammers to effect impression in which mechanical power is applied under electromagnetic control

Definitions

  • ABSTRACT A printer has control means for print hammers which are arranged in columns and each of which is displaceable between a rest position and a print position, and respective deformable elastic bodies are maintained in a deformed condition by the print hammers in the rest position and bias the print hammers toward the print position.
  • the control means for each hammer comprises a first magnetic circuit including a permanent magnet and a portion of the print hammer, and operable to hold the print hammer in the rest position deforming the associated elastic body, and a second magnetic circuit, including a hammer control coil means, operable to release the print hammer from the restposition responsive to a print command and to return the hammer to the rest position after completing a print action.
  • Each print hammer is released, for movement from the rest position by its associated deformable body, by excitation of the associated control coil means in a direction to decrease the magnetomotive force in the print hammer position and, after completing of the print action, the hammer is returned to the rest position by excitation of the associated control coil means in a direction to increase the magnetomotive force inthe print hammer portion.
  • This invention relates to control means for the print hammers of a high-speed printer and, more particularly, to such a control means in which the print hammers are retained in a rest position by magnetic circuit means and are displaced into the print position by the stored energy of deformable elastic bodies maintained in a deformed condition by each print hammer in its rest position, the release of each print hammer being effected in response to a print command signal.
  • a magnetic control means having a first magnetic circuit, including a permanent magnet for holding a print hammer in a hammer rest position storing energy in an elastic body such as a spring, and having a second magnetic circuit including a hammer control coil means for releasing the print hammer from the rest position responsive to a print command
  • a first magnetic circuit including a permanent magnet for holding a print hammer in a hammer rest position storing energy in an elastic body such as a spring
  • a second magnetic circuit including a hammer control coil means for releasing the print hammer from the rest position responsive to a print command
  • a print hammer after finishing the print action, is returned to the rest position by utilizing effectively a magnetic force of the permanent magnet and by exciting only a control coil means, without utilizing the conventional mechanical means, such as cam mechanism and the like.
  • a printer embodying the invention comprises print hammers formed of magnetic material, a first magnetic circuit including a permanent magnet, for holding the print hammers in the rest position, and a second magnetic circuit, including a hammer control coil means, for providing the action of releasing the print hammer from the hammer rest position responsive to a print command, and further returning the print hammer to the rest position after completion of the print action.
  • the first and second magnetic circuits are connected in parallel with the permanent magnet.
  • the hammer control coil means When printing is performed responsive to a print command, the hammer control coil means is excited in a direction such that the magnetic flux, or the magnetomotive force, which flows through a hammer hold portion in the first magnetic circuit for holding the hammer in the rest position, is decreased. After the print action, the print hammer is returned to the rest position by exciting the hammer control coil means in a direction to increase the magnetomotive force in the hammer hold portion of the hammer.
  • the conventional complicated mechanisms for returning hammers fo the rest position becomes unnecessary, and a simple and inexpensive hammer mechanism is provided. Furthermore, by utilizing effectively the magnetic force of the permanent magnet, it is possible to provide a hammer mechanism wherein the efficiency in the hammer portion is increased and the power consumption is reduced.
  • substantially the same power is required to operate the hammer in each column, as well as there being a reduction in the overall power consumption. More specifically, in a magnetic circuit including a permanent magnet for holding a hammer in the rest position, when the hammer is released from the rest position, and in case there is a column in which a hammer has already been released from the rest position, the control coil means of the latter column is excited so that the operating point of the permanent magnet is restored to its original value before the hammer now to be released has been released from the rest position.
  • the force required to hold the hammers in the rest position can be maintained constant, and other columns can be released using the same power as required to release the first column.
  • An object of the invention is to provide a very simple hammer control mechanism designed so that the print hammer, after completing the print action, can be returned to its rest position utilizing only a control coil means in the magnetic circuit for controlling the hammer and without requiring a complicated mechanical means to return the hammer.
  • Another object of the invention is to provide a very simple hammer mechanism which can be assembled and which requires only a small number of parts.
  • a further object of the invention is to prevent a disadvantageous influence upon the hammers of other columns resulting from actuating a print hammer of one column.
  • Another object of the invention is to provide a hammer control mechanism with stable action of the print hammers and a very small power consumption.
  • FIG. 1 is a side elevation view, partly in section, of the operative portion of one column of a high-speed
  • FIG. 6 is a partial side elevation view illustrating a modification
  • FIGS. 7a, 7b and 7c are curves illustrating the operating of the embodiment of the invention shown in FIGS. S- and 6.
  • one column of a high-speed printer embodying the invention is illustrated as including a print hammer l suspended by parallel flexible springs 5.
  • the column further includes magnetic material yokes 2 and 2' extending in spaced, substantially parallel relation from the opposite polarity pole faces of a permanent magnet 3 and having respective attractive faces 20 and 2a forming a hammer-hold arrangement.
  • a hammer control coil means 4 including a hammer release coil 4, and a reset coil 4 for returning hammer l to the rest position, is wound on a member interconnecting yokes 2 and 2.
  • a lever 7, swingable about a pivot 8, is provided for transmitting the force of a spring 6, for driving hammer l, to hammer 1, and a stop is provided to limit movement of transmitting lever 7 in the hammer driving direction.
  • a print drum, on which characters are disposed, is indicated at 16 in association with an ink ribbon 17, whereby printing may be recorded on paper or the like 18 by operation of hammer 1.
  • hammer 1 In its rest position, as illustrated in FIG. I, hammer 1 is attracted to the attractive faces 2a and 2'a of the hammer-hold portion, and is biased toward drum 16 by the spring force of spring 6 acting through lever 7 and constituting a deformable elastic body maintained in a deformed condition by hammer l in its rest position.
  • the permeance P(Bd-I-Id,) of permanent magnet 3, at this time, is shown in FIG. 3.
  • hammer control coil 4 is excited in a direction such that the magnetic flux of the magnetic flux loop ii flowing through hammer release coil 4, is increased when the selected character on drum l6 approaches the front or active end of hammer 1.
  • a magnetic field having the intensity hf is applied to permanent magnet 3 along the characteristic curve of magnet 3, so that the intensity of the magnetic field is decreased from H, to H 1 and the effective magnetic flux in the hammer-hold portion is decreased.
  • the hammer-hold'force is lowered, hammer 1 starts to be actuated toward the character under the force of spring 6.
  • Hammer 1 continues to be supplied with print energy until transmitting lever 7 strikes against stop 10. Then the kinetic energy of hammer 1 causes it to strike against the character, and the print action is performed.
  • hammer reset coil4 is excited in a direction such that the magnetic flux flows in the direction opposite to that indicated in the magnetic flux loop ii shown in FIG. 1.
  • the operating point, on the characteristic curve of permanent magnet 3, at this time, is shown in FIG. 2.
  • a magnetic field of an intensity he in the opposite direction is applied to permanent magnet 3, so that the intensity of the magnetic field is increased from H to H and the magnetomotive force in the hammer-hold portion is increased. This results in attraction of hammer l to the rest position responsive to this increased magnetomotive force.
  • the timing of the return of hammer l is such that the hammer control coil 4 is excited after the hammer strikes against the character.
  • the restoring magnetomotive force can be applied slightly before the hammer strikes against the character.
  • FIG. 4 illustrates one example of the timing of the exciting state of the hammer control coil, in which curve a illustrates the point at which the hammer stikes against the character.
  • Curve [7 illustrate the exciting state of the release coil 4, shown in curve 12,, and of the reset coil 4 shown in curve b
  • FIG. 1 shows an example of the invention wherein release coil 4 and reset coil 4 are used separately as a control coil means 4
  • FIG. 2 illustrates an arrangement in which the release coil 14, and the reset coil 14 are provided in a single control coil means.
  • yokes l2 and 12 extend from respective opposite polarity surfaces of a permanent magnet 13, and the control coil means 14 14 is wound on a magnetic yoke member 14.
  • the yokes l2 and 12' have attractive faces cooperating with a hammer 11.
  • the control as shown in the curve c of FIG. 4 can also be used, particularly if the release signal for hammer 1 or 11 is positive, an opposite polarity signal being applied to the control coil means to return the hammer.
  • the release coil and the reset coil are provided separately as mentioned, so that a coil having a small L and a fast re sponse is used as a release coil, and a coil having a large L and consuming little power, is used as a reset coil.
  • the reaction energy of the hammer when the hammer is reset, the reaction energy of the hammer, after striking the character, can be utilized to a maximum.
  • a complicated device such as a device for absorbing the energy of the hammer, in order to prevent disadvantageous influences caused by the reactionary energy of the hammer, as would be the case in which the hammer were returned to its rest position mechanically as in a conventional printer.
  • the reactionary energy of the hammer there is no disadvantageous influence caused by the above-mentioned reactionary energy of the hammer, in the present invention.
  • FIGS. 1 4 it is not necessary to provide a compliwhereby the embodiment of the invention shown in FIGS. 1 4 is very advantageous.
  • a hammer 21 is suspended by parallel flexible springs 22 and 23.
  • Yokes 24 and 27 have respective attractive faces 24a and 27a forming a hammer-hold portion.
  • Yoke 27 is fixed to yoke 24 through the medium of a member 29 of nonmagnetic material, and a permanent magnet is indicated at 25.
  • Yoke 24 engages one face of magnet 25 and the yoke 26 engages the opposite polarity face of magnet 25 and is connected magnetically with yoke 27 through a gap G.
  • a stand 30 of a non-magnetic material mounts yoke 24.
  • a magnetic circuit is thus provided consisting of a hammer-hold portion and a control portion 28 having coil 28a wound thereabout, said hammer-hold and control portions being disposed in parallel with permanent magnet 25.
  • a transmitting lever 31, pivoted at 32, is provided for transmitting, to the hammer 21, the bias of a spring 34 constituting a deformable elastic body maintained in a deformed condition by hammer 21 in the rest position.
  • Hammer 21 is attracted and held at the hammer-hold portion constituted by the attractive faces 27a and 24a, and is biased toward a character by lever 31.
  • a stop 35 limits motion of lever 31, and a reset cam 33 is provided to return hammer 21 to the rest position after finishing the print action.
  • Hammer 21 is cooperable with characters on a print drum 36, representing a character carrier, and associated,
  • the printer would have a plurality of parallel columns each including a separate hammer, set of yokes, coil, transmitting lever and spring but with odd and even columns each sharing a common permanent magnet.
  • This arrangement is shown in FIG. 5 by a second magnetic circuit associated with hammer 21 each component of the second magnetic circuit being identical with the corresponding component in the abovedescribed circuit, the reference numerals of the second circuit being primed. While the second magnetic circuit associated with hammer 21 is shown provided with a separate permanent magnet 25, a completely independent magnetic circuit cannot be considered on account of leakage of the magnetic flux and the like.
  • the first magnetic circuit will be considered representative of odd columns while the second magnetic circuit (primed reference numerals) will be considered representative of even columns.
  • FIGS. 7a, 7b and 7c graphically illustrate the method of operation of the embodiment of the invention shown in FIGS. and 6.
  • FIG. 7a illustrates the procedure for improving the operating point of the permanent magnet.
  • FIG. 712 A simple control procedure shown in FIG. 712 also can be applied. In this latter case, the operating point of the permanent magnet is improved by continuing to excite the control coil means of the column having a hammer which has already been released from the hold position until the printing cycle is finished. Additional control procedures may readily be used, based upon the arrangement shown in FIGS. 7a and 7b.
  • the hammer-hold portion and the control portion 28 are disposed in parallel with the permanent magnet 25.
  • FIG. 6 only a part of the magnetic circuit is illustrated.
  • a print hammer is illustrated at 41, and yokes 62 and 63, having respective attractive faces 62a and 63a, form the hammer-hold portion, the yokes being associated with respective opposite polarity faces of a permanent magnet 64;.
  • the release coil, for releasing hammer 41 from the rest position, is shown at 65, and a coil 66 is provided for changing the operating point of the permanent .magnet.
  • Hammer 41 is released by exciting release coil 65 so that the magnetic flux of magnetic flux loop i flowing through the hammer-hold portion is decreased.
  • the operating point of permanent magnet 64 is changed as well as in the magnetic circuit shown in FIG. 5.
  • the influence of other columns can be prevented by exciting coil 66 so that the operating point of permanent magnet 64 is returned to its original operating point before the hammer has been released from the hammer rest position, which is also the case with the magnetic circuit shown in FIG. 5.
  • FIG. 7c illustrates one embodiment of this particular control procedure.
  • the subscript 65 of the column number indicates the signal for releasing the hammer from the hammer hold position
  • the subscript 66 illustrates the signal applied to the column which has been already released in order to improve the operating point of the permanent magnet when another column, which has not yet been released, is activated to release its hammer from the rest position.
  • Curve 7c corresponds to the control procedure shown in FIG. 7a, but other control procedures, for example the control procedure shown in FIG. 7b or an improvement on the procedure shown in FIG. 7a and 7b, are possible.
US00335198A 1972-02-24 1973-02-23 Printer Expired - Lifetime US3842737A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP1923472A JPS5227567B2 (it) 1972-02-24 1972-02-24
JP3207172A JPS539130B2 (it) 1972-03-30 1972-03-30

Publications (1)

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US3842737A true US3842737A (en) 1974-10-22

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US00335198A Expired - Lifetime US3842737A (en) 1972-02-24 1973-02-23 Printer

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US (1) US3842737A (it)
FR (1) FR2173608A5 (it)
GB (1) GB1398955A (it)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4134691A (en) * 1976-01-05 1979-01-16 Matschke General Research Company, Inc. Printing head
US4218148A (en) * 1976-01-05 1980-08-19 Printer Associates Matrix printing cell and head assembly
US4258623A (en) * 1979-01-30 1981-03-31 Printronix, Inc. Print hammer mechanism having dual electromagnetic coils and pole pieces
US4279520A (en) * 1978-06-19 1981-07-21 International Business Machines Corporation Print mechanism for wire printer

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2711149A1 (fr) * 1993-10-15 1995-04-21 Michelin & Cie Fil en acier inoxydable pour carcasse d'enveloppe de pneumatique.

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4134691A (en) * 1976-01-05 1979-01-16 Matschke General Research Company, Inc. Printing head
US4218148A (en) * 1976-01-05 1980-08-19 Printer Associates Matrix printing cell and head assembly
US4279520A (en) * 1978-06-19 1981-07-21 International Business Machines Corporation Print mechanism for wire printer
US4258623A (en) * 1979-01-30 1981-03-31 Printronix, Inc. Print hammer mechanism having dual electromagnetic coils and pole pieces

Also Published As

Publication number Publication date
GB1398955A (en) 1975-06-25
FR2173608A5 (it) 1973-10-05

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