US3747521A - Low cost hammer unit - Google Patents

Low cost hammer unit Download PDF

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Publication number
US3747521A
US3747521A US00156780A US3747521DA US3747521A US 3747521 A US3747521 A US 3747521A US 00156780 A US00156780 A US 00156780A US 3747521D A US3747521D A US 3747521DA US 3747521 A US3747521 A US 3747521A
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US
United States
Prior art keywords
hammer
print
armature
leg
hooked
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
US00156780A
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English (en)
Inventor
J Hamilton
J Wallace
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
Original Assignee
International Business Machines 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
Application filed by International Business Machines Corp filed Critical International Business Machines Corp
Application granted granted Critical
Publication of US3747521A publication Critical patent/US3747521A/en
Anticipated expiration legal-status Critical
Expired - Lifetime 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

Definitions

  • a plurality of print hammers are pivotally supported in a nonmagnetic member secured to the plastic body.
  • the print hammers comprise unitary structures each having a hooked armature portion at one end and an angularly disposed extension with a hammer face at the other end for impacting a document for printing thereon.
  • Print hammer structures have heretofore comprised separate electromagnetic actuators and print hammers coupled either by push rods, as in the James M. Cunningham US. Pat. No. 3,241,480, which issued on Mar. 22, 1966, or directly, as in the Derc U.S. Pat. No. 3,507,213, which issued on Apr. 21, 1970, or a unitary structure such as shown in the Potter US. Pat. No. 3,349,696, which issued on Oct. 31, 1967.
  • Another object of the invention is to provide an integrated print hammer unit having a single moving part which is simple to manufacture and is efficient in operation.
  • Yet another object of the invention is to provide for so positioning a single moving element print hammer that a residual compresses to decelerate one end of the moving element while the other end flexes and continues to move to impact a document for performing a print operation thereon.
  • Another important object of the invention is to provide an elastic print hammer and residual in a printer which are so related that the elasticity of the hammer beam and the residual provide an equivalent free flight (dynamic hammer displacement greater than the static hammer displacement) such that printing occurs beyond the nominal platen setting.
  • Another important object of this invention is to provide a print hammer unit having a plurality of magnetic core members molded in a plastic block and a nonmagnetic member secured thereto which has spaced webs defining slots for a plurality of print hammers, one associated with each core member, and receiving a common pivot shaft for, all of the hammers.
  • Yet another important object of this invention is to provide a one-piece print hammer having a hooked armature portion atone end and a resilient angularly disposed extension at the other end with a print hammer face on the side opposite the hooked armature portion.
  • Still another object of the invention is to provide a print hammer module having a plurality of print hammer armature members spaced one or more than one print position apart and having single or multiple width hammer faces to cover the print positions.
  • Another important object of the invention is to provide a one-piece print hammer in which a hooked armature portion on one side of a pivot moves within an operating winding to impact a resilient residual while a hammer face at the end of an elastic extension on the other side of the pivot continues to move in the opposite direction as the extension flexes to impact a document for printing, thus, utilizing the kinetic energy of the resilient extension under control of the residual.
  • FIG. 1 is an enlarged partial end elevational view in section of a print mechanism embodying the invention in one of its forms
  • FIG. 2 is an isometric view exploded in part showing a print hammer assembly embodying the invention of FIG. 1, and
  • FIG. 2a is an isometric view of a Magnetic Core member of FIGS. 1 and 2,
  • FIG. 3 is a timing chart showing the relations between the operating current, impact of the armature against the residual, and impact of the hammer face with the document for printing.
  • a Document 10 is disposed to be advanced by Feed Rolls 12 and 14 past a type carrier, which by way of example, may comprise a relatively thin metal Band 16 ,passing about a pair of spaced apart wheels represented by the one Wheel 11, which is rotatably supported by a shaft 13 on a base 15, upon which is mounted a Platen 17 for backing up the Band 16.
  • the Base 15 may be adjustably supported being, for example, mounted on a Lever 19, adjusted by a Cam 21.
  • Raised Type Characters 18 are located along the Band 16 adjacent to one edge for printing on the document.
  • the Document 10 is disposed to be fed vertically by Feed Roll 12 having, for example, a plurality of SQ f OCket Pins 12a disposed to mesh with holes at the edges of the Document.
  • the Type Characters 18 are moved transversely along the print line of the document being, for example, formed on the endless Band 16, which moves into the plane of FIG. 1, as shown, and is backed up by the Platen 17.
  • Printing is performed on the Document 10 by using an impact paper, ribbon or inked type, by means of a plurality of print hammers such as the Hammer 20, which is shown as comprising an Extension 22 having a Hammer Face 23 at the upper end and an Armature Portion 27 at the lower end.
  • a plurality of print hammers such as the Hammer 20, which is shown as comprising an Extension 22 having a Hammer Face 23 at the upper end and an Armature Portion 27 at the lower end.
  • the Hammer 20 is pivotally mounted by means of a Pivot 26, and the Armature Portion 27 of the Print Hammer 20 includes a Hooked Armature Portion 28 at the end with a rounded configuration which is disposed to be actuated by a substantially U-shaped Magnetic Core Member 30 having an Operating Winding 32 so positioned thereon that it extends beyond the end of the Core Member 30, and so that the Hooked Armature Portion 28 enters the winding and the air gap between the Hooked Armature Portion 28 and the end of the Lower Leg 301 of Core Member 30 is completely within the confines of the Winding 32.
  • a Residual 29 comprising a layer of polyurethane approximately 0.003 in. thick is secured to the face of the Lower Leg 301.
  • the Print Hammer 20 may be mounted as illustrated in FIGS. 1 and 2 by means of a common Pivot Shaft 26, located adjacent the end of the Upper Leg 30a of the Core Member 30, and which extends through openings in a plurality of Ribs 34 of a Hammer Support Block 35, which define Slots 36 therebetween for receiving the upwardly extending Extension Portions 22 of the Print Hammers 20.
  • the Hammer Support Block 35 may comprise a body of aluminum or other suitable non-magnetic material.
  • the Main Body 40 comprises a body of molded plastic material such as a glass-filled phenolic composition or the like. Screws 42 secure the Support Block 35 and the Main Body 40 to a substan tially L-shaped Support Bracket 44 for attachment to the frame of the printer.
  • the Main Body 40 has a plurality of the substantially U-shaped Core Members 30 molded therein in spaced relation, with the Upper Leg 30u of each Core Member 30 slightly projecting therefrom and the Lower Leg 301 of the core member projecting therefrom sufficiently to receive the Operating Winding 32, and project into the winding about twothirds of the way.
  • the Main Body Member 40 may be provided with a plurality of Openings 46 in alignment with the U-shaped Core Members 30 for receiving Springs 48 and Plungers 50, which provide a biasing force for operating on the Armature Portions 27 to as sist in restoring the Armature Portions 27 to their rest position with the Print Hammer Faces 23 spaced from the Document 10.
  • the Hammer Support Block 35 may be also provided with a plurality of openings for receiving threaded Stop Screws 52, which provide a flight time adjustment stop for the Print Hammers 20.
  • the air gap between the Hooked Armature Portion 28 and the Lower Leg 301 of the Core Member 30 is 0.025 in. and the static gap between the Hammer Face 23 and the Document is 0.050 in.
  • the Extension 22 has a width of 0.15 in., a thickness of 0.05 in., and is 1.175 in. long.
  • the Armature Portion 27 has a width of 0.320 in., a thickness of 0.085 in. and an effective length of 0.574 in. With this arrangement the dynamic travel distance of the Hammer Face is on the order of 0.060 in., which includes 0.010 in. of equivalent free flight after the Armature Portion 27 has impacted the Residual 29.
  • the Print Hammer may be operated by means of a Drive Pulse applied to the Operating Winding 32.
  • a current on the order of 3 to 5 amperes with a Winding 32 having approximately 200 turns has been found satisfactory.
  • the Print Hammer 20 starts to move and the drive pulse is terminated before the Hooked Armature Portion 28 impacts the Residual 29 of polyurethane or the like on the Lower Leg 301 of the U-shaped Core Member 30.
  • the Hooked Armature Portion 28 continues to move, compressing the Resid ual 29.
  • the Hammer Face 23 continues to move even further after the Hooked Armature Portion 28 of the Armature has stopped moving, since the elongated Extension 22 of the print hammer is elastic.
  • the Extension 22 has a reduced cross-section and is suffi' ciently long so that it flexes and the Hammer Face 23 continues to move to effect printing on the Document 10 both during compression of the Residual 29 and subsequently during bending of the Print Hammer Extension 22.
  • the Operating Winding 32 is located such that the working gap is approximately one-third of the distance from the armature end of the coil. This allows more efficient use of the magnetic energy, yet minimizes possible mechanical interference between the Hooked Armature Portion and the winding. It also permits adjustment of the air gap between the Lower Leg 301 and the Hooked Armature Portion 28 over a wide range to vary the hammer velocity, which is not possible with magnetic structures having the air gap outside the operating winding, because of increased leakage flux with increased air gap. Since the print hammer has only one moving part, the simple design lends itself to a very low production cost.
  • the Residual 29, in addition to minimizing the residual magnetic flux, is designed to have a certain elasticity to achieve a predetermined amount of hammer equivalent free flight during compression of the residual.
  • the elasticity of the Hammer Extension 22 is also utilized to control the amount of equivalent free flight" developed.
  • the Print Hammer 20 is designed to have the Extension 22 substantially double the length of the Armature Portion 27 and on the order of half the cross-section so as to provide, as shown in FIG.
  • the Print Hammer 20 is designed with an an gularly related upward Extension 22 so as to permit close spacing of the hammer unit to the Document 10 and yet provide a substantially straight document path, as shown.
  • the driving circuit for the Operation Winding 32 is designed, such as by the use of a Zener diode, to allow a controlled current and flux decay once the voltage pulse is turned off. This permits operation of the Print Hammer with a drive pulse width less than the flight time of the Print Hammer (the time the Print Hammer takes to move and impact the Document after application of a voltage pulse to the winding), which increases the efficiency and decreases settle-out time of the device.
  • the energy required for printing is reduced since the Hammer is driven into the Document and Ribbon.
  • the Hammer and Armature are one member, all the mechanical energy developed by the Armature is available for printing.
  • a rigid hammer construction can be utilized by making the Hammer Extension 0.300 in. wide and 0.050 in. thick, and moving the Platen l7 and Type Carrier 16 toward the Print Hammer to reduce the static gap spacing of the Hammer to less than 0.050 in. Printing using the more rigid hammer may be accomplished without the Hooked Armature Portion 28 impacting the Residual 29.
  • An actuator comprising a magnetic core member having a pair of spaced apart legs,
  • a print hammer comprising an armature having a central body portion with a hooked end portion positioned adjacent said end of said one leg and within the extending portion of said winding, a pivot adjacent the end of the other leg of said core member, and an extension at the end of said hammer opposite said hooked end portion having a hammer face thereon.
  • the invention as defined in claim 4 characterized by a plurality of U-shaped magnetic core members molded in a plastic body in spaced apart side-by-side relation, with an attached non-magnetic member having spaced apart ribs between said core member defining slots to receive said print hammers, and a common pivot extending through said ribs to position said armature portion in operating relation with said core memher.

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  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Impact Printers (AREA)
  • Accessory Devices And Overall Control Thereof (AREA)
US00156780A 1971-06-25 1971-06-25 Low cost hammer unit Expired - Lifetime US3747521A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US15678071A 1971-06-25 1971-06-25

Publications (1)

Publication Number Publication Date
US3747521A true US3747521A (en) 1973-07-24

Family

ID=22561061

Family Applications (1)

Application Number Title Priority Date Filing Date
US00156780A Expired - Lifetime US3747521A (en) 1971-06-25 1971-06-25 Low cost hammer unit

Country Status (5)

Country Link
US (1) US3747521A (enExample)
JP (1) JPS539131B1 (enExample)
DE (1) DE2230224C2 (enExample)
FR (1) FR2142967B1 (enExample)
GB (1) GB1321039A (enExample)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3919936A (en) * 1973-02-16 1975-11-18 Pertec Corp High speed line printing apparatus
US3960074A (en) * 1974-09-16 1976-06-01 Shugart Associates Line printer having hammer which spans three print positions
US4210076A (en) * 1977-05-25 1980-07-01 Hitachi Koki Company, Limited Printing apparatus
US4269117A (en) * 1979-07-11 1981-05-26 International Business Machines Corporation Electro-magnetic print hammer
US4392423A (en) * 1978-02-08 1983-07-12 Hitachi, Ltd. Printing hammer driving apparatus
US4446790A (en) * 1978-04-20 1984-05-08 Joseph Konkel Printer with removable print carriage

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5550274U (enExample) * 1978-09-30 1980-04-02
JPS5553199U (enExample) * 1978-10-04 1980-04-09
DE2845806A1 (de) * 1978-10-20 1980-04-30 Documation Inc Hochgeschwindigkeitsdrucker

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3072045A (en) * 1958-06-02 1963-01-08 Bull Machines Sa Triggering electronic devices for the control of electromagnetic actuating devices
US3177803A (en) * 1963-08-02 1965-04-13 Potter Instrument Co Inc Print hammer module and control block therefor
US3188947A (en) * 1963-01-11 1965-06-15 Burroughs Corp Platen actuating means in high speed belt printer
US3233540A (en) * 1961-11-17 1966-02-08 Int Standard Electric Corp Line-at-a-time printer
US3241480A (en) * 1963-03-28 1966-03-22 Ibm Print hammer mechanism and pressure control means in high speed printers
US3349696A (en) * 1965-08-16 1967-10-31 Potter Instrument Co Inc Hammer module assembly in high speed printers
US3468246A (en) * 1967-01-06 1969-09-23 Int Computers & Tabulators Ltd Print hammers with electromagnetic actuating means
US3584574A (en) * 1969-08-14 1971-06-15 Syner Data Inc Hammer module for high-speed line printer

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3196783A (en) * 1963-05-10 1965-07-27 Potter Instrument Co Inc Printer magnet core
GB1179419A (en) * 1966-10-14 1970-01-28 Int Computers Ltd Flying Hammer Solenoid Systems for High Speed Printers
BE755082A (fr) * 1969-08-25 1971-02-01 Ncr Co Dispositif d'actionnement de marteaux d'impression

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3072045A (en) * 1958-06-02 1963-01-08 Bull Machines Sa Triggering electronic devices for the control of electromagnetic actuating devices
US3233540A (en) * 1961-11-17 1966-02-08 Int Standard Electric Corp Line-at-a-time printer
US3188947A (en) * 1963-01-11 1965-06-15 Burroughs Corp Platen actuating means in high speed belt printer
US3241480A (en) * 1963-03-28 1966-03-22 Ibm Print hammer mechanism and pressure control means in high speed printers
US3177803A (en) * 1963-08-02 1965-04-13 Potter Instrument Co Inc Print hammer module and control block therefor
US3349696A (en) * 1965-08-16 1967-10-31 Potter Instrument Co Inc Hammer module assembly in high speed printers
US3468246A (en) * 1967-01-06 1969-09-23 Int Computers & Tabulators Ltd Print hammers with electromagnetic actuating means
US3584574A (en) * 1969-08-14 1971-06-15 Syner Data Inc Hammer module for high-speed line printer

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3919936A (en) * 1973-02-16 1975-11-18 Pertec Corp High speed line printing apparatus
US3960074A (en) * 1974-09-16 1976-06-01 Shugart Associates Line printer having hammer which spans three print positions
US4210076A (en) * 1977-05-25 1980-07-01 Hitachi Koki Company, Limited Printing apparatus
US4392423A (en) * 1978-02-08 1983-07-12 Hitachi, Ltd. Printing hammer driving apparatus
US4446790A (en) * 1978-04-20 1984-05-08 Joseph Konkel Printer with removable print carriage
US4269117A (en) * 1979-07-11 1981-05-26 International Business Machines Corporation Electro-magnetic print hammer
EP0022480B1 (de) * 1979-07-11 1983-06-01 International Business Machines Corporation Elektromagnetischer Druckhammerantrieb

Also Published As

Publication number Publication date
FR2142967B1 (enExample) 1973-07-13
DE2230224A1 (de) 1972-12-28
FR2142967A1 (enExample) 1973-02-02
JPS539131B1 (enExample) 1978-04-04
GB1321039A (en) 1973-06-20
DE2230224C2 (de) 1983-07-07

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