US3711804A - Magnetically restorable high speed print hammer - Google Patents

Magnetically restorable high speed print hammer Download PDF

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Publication number
US3711804A
US3711804A US00134254A US3711804DA US3711804A US 3711804 A US3711804 A US 3711804A US 00134254 A US00134254 A US 00134254A US 3711804D A US3711804D A US 3711804DA US 3711804 A US3711804 A US 3711804A
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United States
Prior art keywords
armature
pole pieces
magnetic flux
core means
portions
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
US00134254A
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English (en)
Inventor
J Kroft
J Pawletko
F Peters
C Young
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.)
International Business Machines Corp
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International Business Machines Corp
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Publication date
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Publication of US3711804A publication Critical patent/US3711804A/en
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F7/00—Magnets
    • H01F7/06—Electromagnets; Actuators including electromagnets
    • H01F7/08—Electromagnets; Actuators including electromagnets with armatures
    • H01F7/14—Pivoting armatures
    • 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
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F29/00—Variable transformers or inductances not covered by group H01F21/00
    • H01F29/14—Variable transformers or inductances not covered by group H01F21/00 with variable magnetic bias
    • H01F2029/143—Variable transformers or inductances not covered by group H01F21/00 with variable magnetic bias with control winding for generating magnetic bias

Definitions

  • An electromagnetic print hammer comprises a Corporatmn, Armonk netic core structure having a magnetic core with an [22] Fil April 15, 1971 armature movable between one flux path and another flux path. Means are provided for producing a mag- [211 Appl' 134354 netic flux in said core structure and control windings are energized to switch the flux from said one to said [52] US. Cl. ..335/266,' 101/93 C another flux path causing the armature to change o i [51] Int. Cl. ..H01f 7/08 tion.
  • electromagnetic actuators for printers have been designed either as separate devices connected to a print hammer by a pushrod or the like, as in the US. Pat. No. 3,241,480, which issued on Mar. 22, 1966, to James M. Cunningham, or as simple armature type actuators impacting a print hammer as in US. Pat. No. 3,507,213 to R. Derc, which issued Apr. 21, 1970.
  • Another object of the invention is to provide an electromagnetic print hammer in which an armature rotatably supported between pole pieces of a stationary magnetic core is actuated by transferring magnetic flux between the pole pieces from one flux path having a radial air gap to another flux path having a peripheral air gap.
  • Yet another object of the invention is to provide an electromagnetically operated print hammer, which is operated by switching magnetic flux from a constant length air gap to a linearly variable air gap.
  • Yet another object of the invention is to provide an electromagnetically operated print hammer, wherein operating windings mounted on portions of pole pieces on either side of a rotatable armature cause a transfer of magnetic flux from a radial toothed air gap between the pole pieces to a linear air gap between the core and armature portions which move towards each other along a path of decreasing length.
  • Still another object of the invention is to provide an electromagnetically operated rotatable print hammer having both drive and impact portions, and a detent and restoring portion.
  • Still another important object of the invention is to provide a print hammer having a rotary impact member with detent teeth and a linear drive air gap.
  • FIG. 1 is a schematic showing in side elevation, partly in section and partly broken out, of an electromagnetically operated print hammer structure embodying the principal features of the invention
  • FIG. 2 is a schematic showing in front elevation of the print hammer structure of FIG. 1,
  • FIG. 3 shows curves illustrating the relative drive force and restore force acting on the armature of the actuator in different positions
  • FIG. 4 shows flight time and print force curves for the actuator of FIGS. 1 and 2 for different values of air gap
  • FIG. 5 shows curves illustrating the timing of drive and damping pulses applied to the print hammer relative to the hammer displacement.
  • the Actuator 10 comprises generally a stationary magnetic core structure having Upper and Lower Core Members 11 and 12 with a Central Core Member 14 positioned therebetween.
  • the Core Members ll, 14 and 12 are connected by Core Members 13 and 15, which complete the magnetic circuit.
  • the upper and lower core members are provided with salient Pole Pieces [6 and 18 having Operating Windings 20 and 22 thereon, respectively.
  • the Intermediate Core Member 14 may comprise a plurality of laminations having upwardly and downwardly disposed salient Pole Pieces 24 and 26 having Operating Windings 28 and 30, respectively.
  • Adjacent the Pole Pieces l6 and 24 and on opposite sides thereof are provided curved or peripheral portions defined by a plurality of spaced Teeth 32 and 33, respectively.
  • the Pole Portions 18 and 26 have similar curved surfaces defined by spaced Teeth 34 and 36, respectively.
  • Armatures 38 and 40 are rotatably supported by means of Pivot Shafts 42 and 44, respectively, and Support Arms 46 and 48, which are respectively secured by means of Pins or Rivets 50 and Screws 52 to support means connecting the Core Members ll, 14 and 12, such as a body of molded Polyurethane Plastic 54 which may be bonded to the core members.
  • the Armatures 38 and 40 are provided with projecting Pole Portions 58 and 60, and 62 and 63, which are positioned so as to move into abutting relation with the corresponding Pole Pieces 16, 24, 18 and 26, respectively, when the Arrnatures 38 and 40 are rotated about their Pivots 42 and 44 in counterclockwise and clockwise directions, respectively.
  • the Armatures 38 and 40 are providedwith corresponding toothedPortions 64, 66, 68 and 70 disposed in cooperative relation with the toothed peripheral Portions 32, 33, 34 and 36 of the Core Members 11, 14 and 12, respectively.
  • the Armatures 38 and 40 are provided respectively with depending and upstanding Arm Portions 72 and 74 having Hammer Faces 76 and 78 for impacting a Document 80 and Ribbon 82 against a Type Element 84, which may be mounted on a type chain, belt or the like for movement past a print position.
  • a Residual 86 of non-magnetic or plastic material such as Polyurethane may be secured to one or both surfaces of the Pole Pieces 16, 18, 24 and 26 to prevent sealing of the armature to the pole pieces when operated.
  • Resilient stops may be provided comprising Flat Springs 88 and 89 with Rubber Bumpers 90 and 91, respectively.
  • the Springs 88 and 89 may be secured in Slots 92 and 93 and adjusting Screws 94 and 95 may be provided for adjusting the rest positions of the Armatures 38 and 40.
  • the Armature 38 is shown in'the operated position with the projecting Pole Piece 58 substantially abutting the Residual 86 of the salient Pole Piece 16 of the stationary Core Member 10.
  • the Hammer Face 76 is impacting the Document 80 and Ribbon 82 with the Type Member 84 for printing.
  • the Teeth 64 and 66 are in offset relation with their corresponding toothed Portions 32 and 33 of the Core Members 1 l and 14, overlapping only about 20-40 percent so as to obtain sufficient restore force.
  • the Armature 40 is shown in the nonoperated position with the Pole Pieces 62 and 18 and 63 and 26 separated their maximum amount. In this position the Teeth 34, 36, 68 and 70 are substantially in alignment.
  • windings on the Core Members and 12 represented by the Winding 17 on Core Member 12 provide a detentmagnetic flux (b2 which normally traverses the radial air gap between the Teeth 36 and 70 and 68 and 34 in sequence.
  • a principal part of the magnetic flux (#2 is switched from the radial path between the spaced peripheral teeth and instead traverses the peripheral or linear air gap path designated by the flux 411 between the Pole Pieces 18, 62, 63 and 26, exerting a drive force on the Armature 40. to operate it in a clockwise direction so as to close up the peripheral or linear air gaps between the pole pieces.
  • the Hammer Face 78 impacts the Document 80 and the Pole Pieces 62 and 18 and 63 and 26 will be substantially in abutting relation with the Residual 86 as shown for the Armature 38.
  • the spaced Teeth 68 and 70 will have, moved'out of alignment with the corresponding Teeth 34 and 36 of the core members and will be in the offset position as shown for the Teeth 64 and 66 of the Armature 38, in which they exert sufficient restore force to return the Armature 40 to the original position as soon as the drive pulse to the Windings 22 and 30 is terminated.
  • the Actuator 10 is a rotary device with two flux paths, one through the large drive air gap between the Pole'Pieces l6 and 58, for example; the other through a relatively short radial gap or variable reluctance path between the spaced Teeth 32 and 64.
  • the actuators With a plurality of actuators arranged in side-by-side relation, as shown in FIGS.
  • a common Winding l9 encompasses the Upper Leg Portions l1 and a common Winding 17 encompasses the Lower Leg Portions 12 of all actuators to provide a steady state magnetic field which forces all units to line up for minimum reluctance values
  • separate Operating Windings and 28 are provided on the salient Pole Pieces l6 and 24 of each of the actuators. In a nonoperated position approximately 10 percent of the main flux produced by the Winding-11 fringes through the air gap between the salient Pole Pieces 16 and 58, which assures a minimum of initial motion delay, while at the same time minimum interaction occurs between adjacent paths.
  • Energization of the Windings 20 and 28 provides sufficient magnetomotive force to cause the magnetic flux to switch paths and a rotational force to develop. This causes the Armature 38 to rotate, and as it rotates, the teeth of the Restore Paths 32-64 and 33-66 saturate, diverting most of the flux into the main air gap between the salient Pole Pieces 16-58 and 60-24.
  • the armature had a radius at the peripheral tooth portion of approximately 0.687 inches, the width of the teeth was approximately 0.047 inches with the slots having a width-of approximately 0.0662 inches.
  • the thickness of the armature is approximately 0.094 inches so that the actuators or print hammers may be arranged on 0.10 inch centers.
  • the gap between armature and core member piece ison the hammer actuators embodying the invention have been operated to provide a print force of approximately 75'230,000 ergs with a response time on the order of 0.6 to 1.1 Ms, a settling time of 1.9 to 3 Ms and a usable stroke of 0.035 to 0.050 inches.
  • drive and damping pulses a and b can be provided in spaced relation to give a displacement curve c.
  • the print hammer actuator of the present invention provides a simple and efficient mechanism which requires no restore springs. Only one moving part per unit is necessary, which part directly impacts to provide the printing force. This enables high speed operation with relatively low drive power and electrical damping, if desired.
  • An electromagnetic actuator comprising,
  • stationary core means of magnetic material having spaced apart pole pieces
  • an armature rotatably positioned between said pole pieces having an actuator extension disposed to be actuated by rotational movement of said armature and having spaced apart projecting portions disposed in predetermined spaced relation with portions of said pole pieces to move into substantially abutting relation therewith upon rotation of said armature,
  • winding means on said pole pieces operable when energized to switch said magnetic flux to another path between said armature and said projecting portions to cause rotary movement of said armature away from said normal position.

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  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Electromagnets (AREA)
  • Impact Printers (AREA)
US00134254A 1971-04-15 1971-04-15 Magnetically restorable high speed print hammer Expired - Lifetime US3711804A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US13425471A 1971-04-15 1971-04-15

Publications (1)

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US3711804A true US3711804A (en) 1973-01-16

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US00134254A Expired - Lifetime US3711804A (en) 1971-04-15 1971-04-15 Magnetically restorable high speed print hammer

Country Status (7)

Country Link
US (1) US3711804A (Direct)
JP (1) JPS5250383B1 (Direct)
CA (1) CA948255A (Direct)
DE (1) DE2217108C3 (Direct)
FR (1) FR2133606B1 (Direct)
GB (1) GB1331211A (Direct)
IT (1) IT947885B (Direct)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1980000552A1 (en) * 1978-09-01 1980-04-03 Ncr Co An apparatus and method for producing cyclic motion
EP0022480B1 (de) * 1979-07-11 1983-06-01 International Business Machines Corporation Elektromagnetischer Druckhammerantrieb

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR102765974B1 (ko) * 2022-12-30 2025-02-11 주식회사 엠에스 오토텍 실러 도포장치

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3305809A (en) * 1964-09-23 1967-02-21 Mac Valves Inc Solenoid with swingable armature
US3609609A (en) * 1968-03-05 1971-09-28 Gen Electric Information Syste High-speed electromagnet

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NL136900C (Direct) * 1963-03-28 Ibm
DE1237816B (de) * 1963-08-24 1967-03-30 Ibm Deutschland Druckhammerantrieb fuer Schnelldrucker
FR1501069A (fr) * 1965-09-30 1967-11-10 Olivetti General Electric Spa Module d'impression pour imprimante à grande vitesse
GB1179419A (en) * 1966-10-14 1970-01-28 Int Computers Ltd Flying Hammer Solenoid Systems for High Speed Printers
FR1543794A (fr) * 1966-12-30 Ibm Système d'entraînement pour un marteau d'impression
DE1613163A1 (de) * 1967-04-12 1970-05-21 Ibm Deutschland Vorrichtung fuer den Antrieb eines Gliedes mit umkehrbarer Bewegungsrichtung
FR1594281A (Direct) * 1967-12-23 1970-06-01

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3305809A (en) * 1964-09-23 1967-02-21 Mac Valves Inc Solenoid with swingable armature
US3609609A (en) * 1968-03-05 1971-09-28 Gen Electric Information Syste High-speed electromagnet

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1980000552A1 (en) * 1978-09-01 1980-04-03 Ncr Co An apparatus and method for producing cyclic motion
US4221163A (en) * 1978-09-01 1980-09-09 Ncr Corporation Magnetic hysteresis driven recording element and method
EP0022480B1 (de) * 1979-07-11 1983-06-01 International Business Machines Corporation Elektromagnetischer Druckhammerantrieb

Also Published As

Publication number Publication date
DE2217108C3 (de) 1981-07-16
FR2133606B1 (Direct) 1975-08-29
IT947885B (it) 1973-05-30
JPS5250383B1 (Direct) 1977-12-23
DE2217108B2 (de) 1980-10-02
CA948255A (en) 1974-05-28
GB1331211A (en) 1973-09-26
DE2217108A1 (de) 1972-10-26
FR2133606A1 (Direct) 1972-12-01

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