EP0023153A1 - Druckhammermechanismus - Google Patents

Druckhammermechanismus Download PDF

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Publication number
EP0023153A1
EP0023153A1 EP80302468A EP80302468A EP0023153A1 EP 0023153 A1 EP0023153 A1 EP 0023153A1 EP 80302468 A EP80302468 A EP 80302468A EP 80302468 A EP80302468 A EP 80302468A EP 0023153 A1 EP0023153 A1 EP 0023153A1
Authority
EP
European Patent Office
Prior art keywords
lever means
hammer
arm
actuating
hammer member
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.)
Ceased
Application number
EP80302468A
Other languages
English (en)
French (fr)
Inventor
Sean Kevin O'brien
Thomas Alan Davenport
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.)
NCR Canada Ltd
Original Assignee
NCR Canada Ltd
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 NCR Canada Ltd filed Critical NCR Canada Ltd
Publication of EP0023153A1 publication Critical patent/EP0023153A1/de
Ceased legal-status Critical Current

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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
    • B41J9/38—Electromagnetic means
    • 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
    • B41J9/127—Mounting of hammers

Definitions

  • the present invention relates to a print hammer mechanism.
  • the invention has particular application to a print hammer mechanism used, for example, in high-speed printers, in which a type element carrier, such as a durm or ribbon, is moved to present a succession of type elements to a hammer which is selectively actuated at the proper instant to produce an imprint of a character on a record medium positioned, usually together with a printing ribbon, between the hammer and the type element.
  • a type element carrier such as a durm or ribbon
  • print hammer mechanisms were proposed in the prior art in which the hammer is propelled into engagement with a selected type element after an actuating member for the hammer has been stopped.
  • Such an arrangement is disclosed, for example, in the U. S. Patent No. 3 643 594.
  • This patent discloses a print hammer mechanism including two rigid rocker arms independently pivoted on a common axle, a first of which has mounted thereon a striker positioned adjacent a type wheel and is held against the second by a return spring.
  • the second rocker arm is arranged to be actuated by an electromagnet to move the first rocker arm with its striker towards the type wheel. During this movement the second rocker arm is stopped but the first rocker arm continues to move bringing the striker into engagement with the type wheel.
  • a problem arising with print hammer mechanisms of the above kind is the difficulty of obtaining a sharp uniform print therewith due to the precision required for ensuring that the face of the striker be in complete alignment upon impact with the face of the type element carried on the wheel.
  • a print hammer mechanism including a lever means pivotally mounted for movement between a rest position and an actuated position; actuating means positioned adjacent one end of said lever means and arranged, when operated, to rotate said lever means to, and to stop said lever means upon reaching, said actuated position; and a hammer member arranged to move together with said lever means upon operation of said actuating means until rotational movement of said lever means is stopped, said hammer member being arranged to continue its movement to bring a hammer tip mounted thereon into engagement with a type element, characterized in that said hammer member is in the form of a flexible cantilever secured at one end to said lever means, said hammer tip being mounted on the free end of said hammer member, whereby upon the stopping of the rotational movement of said lever means the hammer member flexes away from said lever means to a position in which said hammer tip engages said type element.
  • the print hammer mechanism according to the invention is of a simple, low cost, construction allowing the face of the hammer tip to align itself automatically with the face of the print element upon impact.
  • a further advantage of the print hammer mechanism according to the invention is that the hammer member can be arranged to be of low mass thereby permitting high speed of operation.
  • a perspective view of the print hammer mechanism generally indicated by the numeral 20 and comprising a U-shaped support member 22 preferably composed of a metal such as soft iron and having a depending arm portion 24 on which is positioned a coil 26 illustrated in phantom lines.
  • a lever means mounted adjacent the lower edge of a second arm portion 28 of the support member 22 is a lever means indicated generally by the numeral 30 and which comprises an armature arm 32 preferably composed of a metal such as soft iron and rotatably supported on a pin 34 or other suitable pivot means.
  • actuating arm 38 Secured to the rear portion of the armature arm 32 adjacent the pin 34 by means of a pair of screw members 36 (one only shown) is an elongated actuating arm 38 of an inverted T cross-section having an upright portion 40 to which is attached one end of a return spring 42.
  • the actuating arm 38 is preferably fabricated from a plastic material manufactured by the DuPont Corporation of Delaware and sold under the trademark "Delrin”.
  • the return spring 42 normally urges the lever means 30 to a rest position where the armature arm 32 is rotated counter-clockwise about the pin 34 (Fig. 2) until engaging a stop 44 (Figs. 2 and 3) located adjacent the lower edge of the armature arm 32.
  • a hammer member 46 in the form of a flexible cantilever and preferably constructed of spring steel has one end secured to one end of the lower portion of the actuating arm 38 by means of the screws 36 described previously for mounting the actuating arm 38 to the armature arm 32.
  • a hammer tip 48 Secured to the free end of the hammer member 46 is a hammer tip 48.
  • the hammer tip 48 may be soldered or cemented to the hammer member 46 in any conventional manner.
  • the hammer tip 48 Cooperating with the hammer tip 48 is a type element 50 secured to a type support member 52 mounted at a precise angle to allow the hammer tip 48 to impact the type element 50 in a direction which is perpendicular to the face of the type element 50.
  • the type support member 52 is a part of a rotating drum member which sweeps past the hammer tip 48 in a manner that is well-known in the art and which constitutes an on-the-fly printing operation.
  • the armature arm 32 Upon energization of the coil 26, the armature arm 32 is attracted to the arm portion 24 of the support member 22, thereby moving in a clockwise direction as viewed in Fig. 2 against the action of the spring 42.
  • the clockwise movement of the armature arm 32 results in the actuating arm 38, together with the hammer member 46 carried by the arm 38 moving towards the type element 50 until the armature arm 32 impacts on the lower end of the arm portion 24.
  • the impacting of the armature arm 32 on the arm portion 24 results in the sudden stopping of the actuating arm 38 at which time the free end of the hammer member 46 flexes away from such actuating arm 38 (Fig. 3) resulting in the hammer tip 48 impacting against a record medium 54 (such as a paper web) moving the record medium against the type element 50 resulting in the printing of a character on the record medium.
  • a record medium 54 such as a paper web
  • the coil 26 is de-energized, allowing the return spring 42 to rotate the lever means 30 counter-clockwise to the rest position against the stop 44 (Fig. 2). Because of the flexible construction of the hammer member 46, the hammer tip 48 upon impacting the type element 50 will be rotated to a degree, thereby aligning itself, to . provide a uniform contact area between the record medium 54 and the type element 50 resulting in a uniform printing of the character on the record medium. This arrangement eliminates the need for adjusting the mounting of the hammer member 46 with respect to the face of the type element 50 to provide a uniform printing.
  • An important advantage of the present construction resides in the impact time of the hammer tip 48 on the record medium 54.
  • the hammer member 46 and the actuating arm 38 moving together function as an effective rigid assembly.
  • both the actuating arm 38 and the hammer member 46 become separate decoupled masses. Because it acts as being decoupled from the actuating arm 38, the hammer tip 48 functions as a light disconnected mass thereby providing a small impact time on the record medium 54 and allows for the use of a small mass for the hammer tip 48.
  • the maximum flexing of the hammer member 46 will be attained providing a high impact force between the hammer tip 48 and the type element 50.
  • This condition is contrasted to the situation in which the hammer member 46 and the actuator arm 32 were rigidly coupled at the time of contact with the record medium 54. This latter condition would present more mass on impact, and therefore, a longer duration of contact or dwell time between the hammer tip 48 and the type element 50.
  • the dwell time By reducing the dwell time, the printing speed of the print hammer mechanism 20 may be increased without the attending danger of smearing the image of the printed character.
  • the spring 42 has been disclosed as the means to return the lever means 30 to its rest position, it has been found that under certain circumstances a permanent magnet (not shown) located adjacent the upright portion 40 of the actuating arm 38 provides an effective dampening means to return the lever means 30 to the rest position upon the de-energization of the coil 26.
  • the coil 26 when energized, is capable of overcoming the strength of the permanent magnet enabling a hammer operation to occur in the manner described previously.
  • the actuating arm 38 is preferably constructed of a'metal such as soft iron.

Landscapes

  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Impact Printers (AREA)
EP80302468A 1979-07-23 1980-07-21 Druckhammermechanismus Ceased EP0023153A1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US5987279A 1979-07-23 1979-07-23
US59872 1979-07-23

Publications (1)

Publication Number Publication Date
EP0023153A1 true EP0023153A1 (de) 1981-01-28

Family

ID=22025843

Family Applications (1)

Application Number Title Priority Date Filing Date
EP80302468A Ceased EP0023153A1 (de) 1979-07-23 1980-07-21 Druckhammermechanismus

Country Status (3)

Country Link
EP (1) EP0023153A1 (de)
JP (1) JPS5617279A (de)
CA (1) CA1139988A (de)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0124382A2 (de) * 1983-05-03 1984-11-07 Ncr Canada Ltd - Ncr Canada Ltee Druckkammeranordnung für einen Anschlagdrucker

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3504623A (en) * 1968-04-03 1970-04-07 Itt Hammer arrangement for high-speed printers
US3749008A (en) * 1971-02-04 1973-07-31 Ibm Print hammer assembly
FR2356517A1 (fr) * 1976-07-01 1978-01-27 Ibm Mecanisme de frappe pour imprimante

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3504623A (en) * 1968-04-03 1970-04-07 Itt Hammer arrangement for high-speed printers
US3749008A (en) * 1971-02-04 1973-07-31 Ibm Print hammer assembly
FR2356517A1 (fr) * 1976-07-01 1978-01-27 Ibm Mecanisme de frappe pour imprimante

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0124382A2 (de) * 1983-05-03 1984-11-07 Ncr Canada Ltd - Ncr Canada Ltee Druckkammeranordnung für einen Anschlagdrucker
EP0124382A3 (en) * 1983-05-03 1985-12-27 Ncr Canada Ltd - Ncr Canada Ltee Print hammer assembly for an impact printer

Also Published As

Publication number Publication date
CA1139988A (en) 1983-01-25
JPS5617279A (en) 1981-02-19

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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

17P Request for examination filed

Effective date: 19810626

DET De: translation of patent claims
STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION HAS BEEN REFUSED

18R Application refused

Effective date: 19840204

RIN1 Information on inventor provided before grant (corrected)

Inventor name: DAVENPORT, THOMAS ALAN

Inventor name: O'BRIEN, SEAN KEVIN