US3906854A - Print hammer control mechanism - Google Patents

Print hammer control mechanism Download PDF

Info

Publication number
US3906854A
US3906854A US437253*A US43725374A US3906854A US 3906854 A US3906854 A US 3906854A US 43725374 A US43725374 A US 43725374A US 3906854 A US3906854 A US 3906854A
Authority
US
United States
Prior art keywords
hammer
control
print
rest position
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
US437253*A
Other languages
English (en)
Inventor
Yoshifumi 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
Original Assignee
Suwa Seikosha KK
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
Application filed by Suwa Seikosha KK filed Critical Suwa Seikosha KK
Application granted granted Critical
Publication of US3906854A publication Critical patent/US3906854A/en
Anticipated expiration legal-status Critical
Expired - Lifetime 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
    • B41J9/26—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

  • a printer is provided with a plurality of print hammers, each hammer being maintained in a rest position engaging a deformed elastic body by a hammer control mechanism.
  • the hammer control mechanism includes individual magnetic circuits in combination with a magnetic flux producing element which is pro vided for selectively maintaining each of the print hammers in the rest position and for selectively releasing print hammers to effect printing.
  • Each magnetic circuit includes a hammer hold portion and a control portion, the hammer hold and control portions being connected in parallel with the magnetic flux producing element.
  • the control portion further includes a permanent magnet and a control coil for effecting release of said hammer from its rest position.
  • Each of the print hammers is released from the rest position by exciting the control coil in the control portion in a first direction to effect a reverse of the polarity of said permanent magnet to thereby decrease the magnetomotive force applied to the print hammer to hold the print hammer in the rest position, the displacement of the print hammer being the product of the release of the energy of the elastic body.
  • the hammer is then returned to a rest position by a return mechanism as the control coil is excited in the opposite direction, the excitation of the coil to return the polarity of the magnet in the control portion resulting in a more responsive hammer control.
  • This invention relates generally to a control mechanism for the print hammers of an on-the-fly printer, and particularly to a control mechanism for such print hammers wherein displacement of any individual print hammer has no influence upon the operation of any other adjacent print hammer.
  • printers wherein the print hammers are held in a rest position by a flux producing element and are forced into contact with a printing surface by a deformed elastic body have taken various forms
  • embodiments of such printers incorporating a single permanent magnet for a plurality of print hammers have yielded results which are less than completely satisfactory. Because the force which is utilized to overcome the deformed elastic body is the force of a permanent magnet, and because it is necessary to reduce the force in order to release the hammer, a change in the reluctance of the portion of the magnetic circuit including the permanent magnet and the print hammer occurs upon the release of each print hammer.
  • a printer having a plurality of print I hammers displaceable between a rest position and a print position, an elastic body maintained in a deformed state by each of said print hammers at its rest position, and a magnetic circuit control means associated with each of said columns for selectively holding each said print hammer at its rest position and releasing same for displacement to a print position.
  • the magnetic circuit control means includes a magnetic flux producing element common to at least two of said columns, and a first hammer hold magnetic circuit portion associated with each print hammer including a portion associated with each print hammer including a release coil and a permanent magnet associated therewith, the release coil including means for applying signals thereto.
  • the first and second magnetic circuit portions are connected in parallel with the magnetic flux producing element, each of the magnetic circuit control means being adapted to hold the respective hammers in a rest position and to release the respective hammers on application of a signal to its control coil means by means of said signal applying means in a first direction so as to reverse the polarity of the permanent magnet and thereby decrease the magnetomotive force applied to same hammer. the energy stored in the respective deformed body displacing said respective hammer from said rest position to said print position upon said decrease in said magnetomotive force.
  • a mechanism for returning the respective hammer to a rest position is provided, the coil signal applying means applying a second signal to the coil to thereby return the permanent magnet to its original polarity coincident with the return of the hammer, to effect an improved hammer control.
  • Another object of the invention is to provide an improved hammer control mechanism for a printer which may be actuated by relatively small control current to thereby effect small power consumption.
  • Still another object of the invention is to provide a printer having a plurality of hammers controlled by a common magnetic flux producing element and individual column circuit control devices wherein the operation of one of said hammers does not affect operation of any of the adjacent hammers.
  • Still a further object of the invention is a printer having a plurality of hammers controlled by individual column circuit control devices wherein a high response speed is effected by utilizing a minimum of power.
  • Still another object of the invention is to provide a printer and a plurality of hammers controlled by a single flux producing element common to each of the hammers, and individual column magnetic circuit control devices each including a permanent magnet.
  • FIG. I is a partially sectioned side elevational view of the operative portion of one column of a printer constructed in accordance with the prior art
  • FIGS. 2 and 3 are partially sectioned side elevational views of the operative portion of one column of a printer including an improved hammer control mechanism constructed in accordance with the instant invention
  • FIG. 4 is a graphical representation of a hysteresis loop of the control permanent magnet utilized in the embodiment depicted in FIGS. 2 and 3;
  • FIG. 5 is a side elevational view of a second embodiment of an operative portion of one column of a printer including an improved hammer control mechanism constructed in accordance with theinstant invention.
  • FIG. 1 one column of a multicolumn printer constructed in accordance with prior art is depicted.
  • the printer includes a hammer I mounted for longitudinal displacement on suspending springs 2.
  • a magnetic circuit for the control of the displacement of the hammer is provided having a first portion consisting of yokes 3 and 4 for holding hammer l in a rest position by means of a magnetic field caused by fluit from a permanent magnet 6 and depictcd as loop i.
  • a second portion of the magnetic circuit illustrated by loop ii is formed by permanent magnet 6, yoke 3, yoke 4, an additional yoke 5, and a control coil 8 wound about yoke 5.
  • hammer 1 The rear end of hammer 1 is disposed in contact with transmitting lever 9, which lever is pivoted about pivot 9' and which lever further engages and deforms drive spring 10 when the hammer is in the rest position as illustrated in FIG. 1.
  • the stroke of transmitting lever 9 is limited by a stopper 12 which is struck by said lever before the hammer strikes recording paper and inked ribbon 14 against print drum 13.
  • Reset cam 11 is provided for returning the print hammer and spring to a rest position after the hammer is operated and the printing is completed by rotating cam 11 against the lower portion of the transmitting lever 9 to thereby deform the spring into the rest position.
  • Printing is effected by engagement of the front end of the hammer 1 against the recording paper 15 to force the recording paper against the ink ribbon 1 4 and the surface of a character-carrying drum 13.
  • Drum 13 is continuously rotating and has a series of characters circumferentially spaced in alignment with the column represented by FIG. 1. In practice, one such circumferential arrary of characters will be provided for each column of the printer. The characters may consist of the symbols, numbers or letters desired.
  • FIG. 1 The operation of the prior art arrangement depicted in FIG. 1 is understood by making reference thereto wherein the hammer is depicted at a rest position. At this'position hammer l is held by yokes 3 and 4 due to the holding force generated by the flux loop 1' which includes the hammer, yokes 3 and 4 and permanent magnet 6. The holding force applied to hammer l is sufficient to overcome the driving force of drive spring 10 and is further sufficient to hold the hammer in position despite the influence of changes in temperature, vibration and the like. As hereinabove noted, a second loop ii is formed, including permanent magnet 6, and is con nected in parallel with the first loop 1' through permanent magnet 6. As noted above, a character carrying drum 13 rotates at a predetermined speed.
  • a signal is applied to control coil 8.
  • the direction of the signal appliedto the control coil 8 is such as to increase the quantity of magnetic flux flowing in magnetic flux loop ii.
  • the magnetic flux in loop ii is increased, the flux in loop i between the points A and B is decreased, thus decreasing the holding force on the hammer, allowing the holding force to be overcome by the force of drive spring 10 acting upon the hammer.
  • the print hammer is driven in the direction of the character on the print drum by the spring and continues to be supplied with energy until transmitting lever 9 is brought into contact with stopper 12. If the print hammer strikes against the character drum the printing function is performed. The print hammer rebounds off the print drum and is returned to the rest position, spring 10 being returned to the rest position by reset cam 11.
  • the operation of the prior art hammer is less than completely satisfactory in view of the following.
  • the operating point of the permanent magnet is changed. Alteration of the operating point of the permanent magnet affects the adjacent columns which have hammer control magnetic circuits cooperating with the same permanent magnet, the hammers of which have not yet been released from their respective hammer hold positions.
  • the change in operating point of the permanent magnet at the released hammer column increases the amount of magnetic flux flowing to the hammer hold portion of the magnetic circuits of the adjacent columns which have not yet been released.
  • FIGS. 2 and 3 wherein a printer control mechanism for eliminating the abovementioned defects is depicted.
  • a print hammer 21 is depicted in FIG. 2 in a rest position where it is held thereby by a hammer hold magnetic circuit consisting of yokes 23 and 24 having attractive faces 23a and 24a respectively for holding hammer 21 in a rest position, as illustrated in FIG. 2, by means of the magnetic field caused by the flux from a permanent magnet 26 and depicted as loop iii.
  • a hammer control circuit is illustrated by loop v and is formed by permanent magnet 26, a portion of yoke 24, a portion of yoke 23, a control permanent magnet 27, coil core 25, and a control coil 28 wound about coil core 25, control permanent magnet 27 and yoke 23.
  • Both the hammer hold circuit illustrated as loop iii, and the magnetic control circuit illustrated as loop v are connected in parallel with permanent magnet 26 for holding the hammer and releasing same in the same manner as depicted in FIG. 1.
  • the control permanent magnet 27 is selected so that when the hammer is in a rest position, the polarities of the control permanent magnet 27 and the permanent magnet 26 face each other in the manner depicted in FIG. 2.
  • the hammer In operation, the hammer remains at a rest position, as depicted in FIG. 2.
  • the control coil 28 is excited in a first direction so as to reverse the direction in the polarity of the control permanent magnet 27 and change the polarity of the control permanent magnet thereby reducing the magnetomotive force be- 27 and the permanent magnet 26 have opposite ,polarities facing each other.
  • netic flux loop vii isdecreased rapidly.
  • print hammer is returned by action of a cam in the
  • FIG. 4 wherein a hysteresis loop of the control permanent magnet 27 provided in a control magnetic circuit is depicted.
  • the operating point of the control permanent magnet 27 is at a point a.
  • the control coil 28 is energized to effect a release of the hammer, the operating point of the permanent manget is moved from point a to point b.
  • the f point of the hysteresis loop is the point at which the control permanent magnet 27 is rapidly reversed and since the point a is so close thereto, a small application of current to the control coil will affect an immediate and rapid reversal of polarities in the control permanent magnet.
  • control coil 28 When control coil 28 ceases to be energized, the operating point of the control permanent magnet is moved to point c on the hysteresis loop. At that point, magnetic flux is flowing through the magnetic flux loop vi depicted in FIG., 3. Accordingly, by selecting point c in the hysteresis loop at a proper position, it is possible to eliminate the defect described with respect to a hammer mechanism'shown in FIG. 1, namely, that the operation time of the hammer is altered when the hammer is operated because the hold force for the print hammers in the adjacent columns not having been released is increased.
  • the print hammer Upon completing the printing action, the print hammer is returned to its rest position in the usual manner.
  • the polarity of the control permanent magnet is returned to the direction depicted in FIG. 2, by applying a signal of a second direction to control coil 28.
  • the operating point thereof Upon the return of the polarity of control permanent magnet 27 the operating point thereof is moved along the hysteresis loop from points 0, to d, to e.
  • the operating point of the control permanent magnet Upon termination of excitation in that direction, the operating point of the control permanent magnet is returned from point e to point a and the hammer mechanism is returned to the rest position depicted in FIG.
  • the magnetic flux produced from the permanent magnet 26 does not separately flow through the magnetic loop 1' and ii at the time the hammer is attracted such as the conventional hammer mechanism depicted in FIG. 1. Moreover, since the magnetic flux from the permanent magnet 26 can be minimized a small magnet for holding the hammers will become particularly adapted for such use. Further, the response time as well as a decrease inthe power consumed thereby will be effected and, the effect of operating hammers on adjacent columns will be eliminated.
  • FIG. 5 wherein a hammer controlmechanism forcontrolling the release of hammer 31 is depicted.
  • a yoke 33 including an electromagnet 36 wound therearound, and having hammer attractice faces 33a and 33b to definea hammer hold, circuit while maintaining hammer 31 at a rest position.
  • core 35 includes a control permanent magnet 37 therein, and a control coil 38 wound therearound. It isunderstood, that the only differences between the hammer control mechanism depicted in FIG. 5 and the one depicted in FIG. 2 is that permanent magnet 4 maintaining the hammer in a rest position is replaced by an electromagnet formed by yoke 33 and coil 36, the operation being the same as the mechanism described above, and providing the same improved response time during operation.
  • respective hammer control means for print hammers which are arranged in a plurality of columns and each of which is displaceable between a rest position and a print position, and having respective deformable elastic bodies maintained in deformed condition by the associated print hammers in the rest position
  • improved magnetic circuit control means comprising holding means for holding each said print hammer at said rest position, releasing means for selectively displacing said print hammer to said print position, and means for producing a magnetic flux, a first hammer hold magnetic circuit associated with each print hammer including a portion of the associated print hammer and a second control magnetic circuit associated with each print hammer including a control permanent magnet and control coil means, said control coil means including means for applying a pulse thereto, said first magnetic circuit and second magnetic circuit being connected in parallel with said magnetic flux producing means, each of said magnetic circuit control means being adapted to hold said respective hammers in said rest position and to release said respective hammers upon application of a pulse to the control coil means by means of said signal applying means

Landscapes

  • Impact Printers (AREA)
US437253*A 1973-01-26 1974-01-28 Print hammer control mechanism Expired - Lifetime US3906854A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP48010807A JPS523762B2 (enrdf_load_stackoverflow) 1973-01-26 1973-01-26

Publications (1)

Publication Number Publication Date
US3906854A true US3906854A (en) 1975-09-23

Family

ID=11760601

Family Applications (1)

Application Number Title Priority Date Filing Date
US437253*A Expired - Lifetime US3906854A (en) 1973-01-26 1974-01-28 Print hammer control mechanism

Country Status (5)

Country Link
US (1) US3906854A (enrdf_load_stackoverflow)
JP (1) JPS523762B2 (enrdf_load_stackoverflow)
DE (1) DE2403788A1 (enrdf_load_stackoverflow)
FR (1) FR2215325B1 (enrdf_load_stackoverflow)
GB (1) GB1417492A (enrdf_load_stackoverflow)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4167343A (en) * 1976-09-27 1979-09-11 Golobay Gary L Print wire actuator mechanism
US4233894A (en) * 1978-06-02 1980-11-18 Printronix, Inc. Print hammer mechanism having dual pole pieces
US4461207A (en) * 1980-11-17 1984-07-24 International Business Machines Corporation Actuator mechanism for a printer or the like using dual magnets
US4995744A (en) * 1988-12-16 1991-02-26 International Business Machines Corporation Impact printer actuator using magnet and electromagnetic coil and method of manufacture

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5430792U (enrdf_load_stackoverflow) * 1977-08-03 1979-02-28
US4423675A (en) * 1982-03-08 1984-01-03 Hewlett-Packard Company Magnetic circuit and print hammer
JPS59218871A (ja) * 1983-05-27 1984-12-10 Matsushita Electric Works Ltd ドツトプリンタ用電磁石装置
JPS60143468U (ja) * 1984-03-02 1985-09-24 株式会社　古河第一自動車学校 自動車運転教習用駐車車両装置

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3089064A (en) * 1958-02-08 1963-05-07 Electro Chimie Metal Combined permanent magnet and electromagnet
US3285166A (en) * 1964-12-18 1966-11-15 Data Products Corp High speed print hammer and bar magnet means
US3416442A (en) * 1967-06-20 1968-12-17 Ibm Selective hammer actuating means in chain printers
US3707122A (en) * 1970-07-13 1972-12-26 Peripheral Dynamics Print hammer mechanism with magnetic reinforcement to cath hammer

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3089064A (en) * 1958-02-08 1963-05-07 Electro Chimie Metal Combined permanent magnet and electromagnet
US3285166A (en) * 1964-12-18 1966-11-15 Data Products Corp High speed print hammer and bar magnet means
US3416442A (en) * 1967-06-20 1968-12-17 Ibm Selective hammer actuating means in chain printers
US3707122A (en) * 1970-07-13 1972-12-26 Peripheral Dynamics Print hammer mechanism with magnetic reinforcement to cath hammer

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4167343A (en) * 1976-09-27 1979-09-11 Golobay Gary L Print wire actuator mechanism
US4233894A (en) * 1978-06-02 1980-11-18 Printronix, Inc. Print hammer mechanism having dual pole pieces
US4461207A (en) * 1980-11-17 1984-07-24 International Business Machines Corporation Actuator mechanism for a printer or the like using dual magnets
US4995744A (en) * 1988-12-16 1991-02-26 International Business Machines Corporation Impact printer actuator using magnet and electromagnetic coil and method of manufacture

Also Published As

Publication number Publication date
FR2215325B1 (enrdf_load_stackoverflow) 1982-10-08
FR2215325A1 (enrdf_load_stackoverflow) 1974-08-23
DE2403788A1 (de) 1974-08-01
GB1417492A (en) 1975-12-10
JPS523762B2 (enrdf_load_stackoverflow) 1977-01-29
JPS49132934A (enrdf_load_stackoverflow) 1974-12-20

Similar Documents

Publication Publication Date Title
US3049990A (en) Print hammer actuator
US3217640A (en) Electromagnetic actuating means for wire printers
US3335659A (en) Print hammer drive mechanism for high-speed printers
US3906854A (en) Print hammer control mechanism
EP0155816B1 (en) Dot printer head
US3842737A (en) Printer
US3623428A (en) Flying printer
JPS59209893A (ja) 高速プリンタ用高速叩打型ハンマ
US3878778A (en) Printer
US3834305A (en) Printer
US3842734A (en) Printer
JPS61501383A (ja) プリンタ−
USRE29745E (en) Printer
US3598046A (en) Print hammer interposer and actuating means in flying printers
JPH0254785B2 (enrdf_load_stackoverflow)
US4264219A (en) Device for driving dot printing bars in a dot printer
US5039235A (en) Printer utilizing improved impact dot print head
GB968185A (en) High speed printing mechanism
JPH0371272B2 (enrdf_load_stackoverflow)
JPH0211338A (ja) ワイヤドットプリンタ
JPS59103767A (ja) 印字機構
JPH0313353A (ja) インパクトドットヘッド
JPS5820469A (ja) 印字装置
JPH0434508B2 (enrdf_load_stackoverflow)
JPS6356071B2 (enrdf_load_stackoverflow)