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Publication numberUS3828908 A
Publication typeGrant
Publication dateAug 13, 1974
Filing dateDec 26, 1972
Priority dateJan 11, 1972
Also published asDE2201049A1, DE2201049B2, DE2201049C3
Publication numberUS 3828908 A, US 3828908A, US-A-3828908, US3828908 A, US3828908A
InventorsSchneider W
Original AssigneeSchneider W
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Mosaic print head
US 3828908 A
Abstract  available in
Images(2)
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Claims  available in
Description  (OCR text may contain errors)

ilnited States Patent [191 Sehneider MOSAIC PRINT HEAD Winiried Schneider, SchloB Neuhaus, Adlerweg 16, Germany Filed: Dec. 26, 1972 Appl. No.: 318,487

Inventor:

[30] Foreign Application Priority Data Jan. 11, 1972 Germany 2201049 11.5. C1. 1.97/1 R, 101/93 C, 335/274 Int. Cl B4lj 33/00 Field of Search 197/1 R; 101/93 C, 93 N;

References Cited UNITED STATES PATENTS 10/1965 Severn 335/274 X 9/1969 Paige 197/1 R 7/1971 Chou'et a1. 101/93 C X Aug. 13, 1974 3,672,482 I 6/1972 Brumbaugh et al 197/] R 3,729,079 4/1973 Zenner et a1 101/93 C X Primary Examiner-Robert E. Pulfrey Assistant Examiner-E. H. Eickholt Attorney, Agent, or FirmMcGlew and Tuttle [5 7 1 ABSTRACT IIIIIIII riiili llllill lilillll llll I 1- I1 I rr [[1]] I I ll iill l [J III] PATENIEDAUBI 31914 SHEET '1 OF 2 PAIENIEDAUMI H 3828.908.

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FIG?

MOSAIC PRINT nnAn BACKGROUND OF THE INVENTION 1. Field of the invention This invention relates in general to printing devices and, in particular, to a new and useful mosaic printing head having a plurality of vertically arranged needles which are actuated by a movable armature and which includes a spring member disposed between the armature and the needle head.

2. Description of the Prior Art The present invention particularly relates to a mosaic print head in which the printing needles are actuated by flap-armature magnets, and particularly to the guidance and design of the printing needles.

In such mosaic print heads, the printer magnets are mostly arranged on a circular arc, with the conical flap armatures directed towards the center of the circle and actuating the printing needles via these ends. Because of the spatial extent of the magnetic systems, the printing needles are spread asunder at the upper end and are so guided at the printing side that their ends lie in one plane and thus form the printing column. To achieve an advantageous transmission of the force from the magnets, the printing needles are slightly curved so as to be guided approximately perpendicularly in the lower part.

The upper end of the printing needles terminates in a wider portion (hat), which serves as pressure surface, with the needle permanently connected with the hat and the latter loosely resting against the armature or loosely guided therein and, by means of a spiral spring, forced against the armature.

This design of the mosaic print head, and particularly the fact that the hat loosely rests against the flap armature, requires a relative movement between the flap armature and the needle end which, due to the relatively small bearing surface of the hat and to the high printing rate, results in considerable attrition and, consequently, in undesirable wear. Another critical wearing spot is the needle point, which, when forced against the paper, first rounds off and then is subject to heavy wear.

SUMMARY OF THE INVENTION In accordance with the invention, there is provided a printing head which does not have the disadvantages of the prior art and which includes a leaf spring disposed between a movable armature and the electromagnetic core and which is preferably formed as a continuous annular curve with individual radially extending finger elements and which engage between the armature and the needles to actuate the needles upon movement of the armature.

The invention is characterized in that, for reducing curved, and, finally, the bearing surface between the armature and the leaf spring is considerably larger than in the known systems. The result is that attrition is virtually negligible.

In addition, since the hat and the pressure spring areno longer required, a reduction in the mass to be moved during printing is obtained, which fact, together with the likewise reduced friction between the needle head and the armature, the reduced curvature of the needle as well as the possibility of adapting the progressive load deflection curve of the leaf spring to the characteristic of the magnetic force, can be utilized to considerably increase the printing rate.

The comb-like design of the leaf spring simplifies the manufacture; also, no clamping of the leaf-spring comb is necessary if only a protection against torsion is provided. If non-ferromagnetic or almost non-magnetic material is used for the leaf spring, the otherwise necessary anti-sticking foil between the armature and the yoke can be dispensed with.

With the conventional printing wires made of carbon steel, alloy steels, or tungsten, the point of the printing needle wears rapidly. However, if a carbide tip is attached to the end of the printing needle, wear is considerably reduced.

Another possibility of producing wear-resistant printing needles is to make them of titanium and to convert the point into titanium carbide or titanium nitride. The point can be converted completely or partially; in the latter case, a soft, tough core is preserved. This conversion of the point can also be achieved with tungsten, tantalum, molybdenum, or chromium. A considerable advantage of titanium, however, is its low specific gravity and, consequently, a higher printing rate.

Accordingly it is an object of the invention to provide an improved mosaic print head in which a bundle of needles are guided for vertical movement and arranged centrally within circumferentially spaced flap armatures and wherein a leaf spring is disposed between the armature and the individual needles and engages the needles for actuating them upon movement of the armature.

A further object of the invention is to provide a mosaic printing head which is simple in design, rugged in construction and economical to manufacture.

For an understanding of the principles of the invention, reference is made to the following description of typical embodiments thereof as illustrated in the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWING In the drawings:

FIG. 1 shows a partial section through the novel mosaic print head;

FIG. 2 is a top view of this mosaic print head with partially removed cover;

FIG. 3 shows part of another embodiment-of the novel mosaic print head in a sectional view;

FIG. 4 is a top view of this mosaic print head, and

FIG. 5 shows the novel design of a printing needle.

FIG. 1 shows the novel mosaic print head, scaled up to about twice its natural size. For clarity, only one printing needle 1 is shown. The printing ends of the needles lie one after the other in one plane and form the printing column; this is shown schematically in FIG. 2. The printing end of the printing needle 1 is guided in the guide 2.

The magnetic systems for actuating the printing needles I are arranged on a circle as shown in FIG. 2. The sectional view of FIG. I shows that the magnet yoke 4 is U-shaped. Located between the legs of the magnet yoke 4 is the core 5, around which the field coil 6 is wound. The magnet yoke 4 is common to all magnetic systems and forms an integral part, so that two concentric cups consisting of one turned part are obtained. FIG. 2 also shows that the coil cores are cylindrical, as well s the design of the flap armature 3. The latter has a wide bearing portion, which is placed into the groove 7 extending all around and rests on the core 5. To reduce the bouncing of the needles and to limit the stroke, the ring 8 made of elastic material is provided.

According to a feature of the invention, a comb-like leaf spring 9, whose design can be seen in FIG. 2, is located between the armature 3 and the core 5. Attached to those ends of the tongues of the leaf spring 9 which are directed towards the center of the circle are the upper ends of the printing needles 1;

As can be seen in FIG. 1, the tongues 10 can be placed very close to the center of the circle, so that the printing needles 1 are curved outwardly toward their tops only very little. The leaf spring 9 lies loosely and under slight resilient pretension between the armature 3 and the core 5 and is protected against torsion only by the torsion protection 11.

The ferromagnetic lamina 12 joined to the armature 3 serves to increase the magnetic flux via the outer jacket 13, the armature 3, and the core 5, whereby the armature force is increased. The resulting increase in the inertia of the system is negligible because the lamina l2 lies near the armature fulcrum and is relatively small. The lamina 12 can be joined to the armature 3 by spot welding or projection welding.

FIGS. 3 and 4 show another embodiment of the invention in which the printing needles 1 are passed through that end of the tongue of the leaf-sprint comb 14- which is directed toward the center of the circle, and are secured against slipping by the small hat 15. As

in the example of FIGS. 1 and 2, the relative movement between the armature and the leaf spring is nearly zero.

FIG. 5 shows the novel design of the printing needle I in which the tip 16 is made of cemented carbide to achieve a reduction in wear. The carbide tip 16 may be attached, for example, by soldering or by laser-beam welding. This also reduces the wear to which the needle point is subjected in the guide 2, which has a favorable effect on the type.

While specific embodiments of the invention have been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles.

. I claim:

I. A mosaic printing head, comprising at least one elongated printing needle, needle guide means for holding said needle substantially vertically and permitting substantial vertical axial movement thereof for printing, an electromagnet including a pole core, an armature having a first end movable toward and away from said pole core and an opposite second end, means pivotally supporting the opposite second end of said armature, and a leaf spring having a first end supported between said first end of said armature and said pole core and having a second end engaged with said needle to displace said needle upon movement of said armature.

2. A mosaic print head, according to claim 1, wherein there are a plurality of needles arranged in spaced circumferential locations, said needles each having an armature, said leaf spring comprising a comb-like member having comb fingers disposed between the armature and the associated needle.

3. A mosaic print head, according to claim 1, wherein said leaf spring is made of a non-ferromagnetic material.

4. A mosaic print head, according to claim 1, wherein said needle is joined to said leaf spring by a weld.

5. A mosaic print head, according to claim 1, wherein said leaf spring includes a tongue portion having a hole therethrough for the passage of the needle therethrough, and a hat engaged over the hole for holding the needle in position.

6. A mosaic print head, according to claim 1, wherein said needles have a carbide tip secured thereto.

7. A mosaic print head, according to claim 1, wherein said printing needle is made of titanium having a tip made at least partially of titanium caribde.

8. A mosaic print head, according to claim 1, wherein said printing needle is made of one of the following: tungsten, tantalum, molybdenum, vanadium and chromium, and wherein the needle has a point comprising a carbide material.

9. A mosaic print head, according to claim 1, including a ferromagnetic laminar secured to said armature adjacent its pivotal mounting and covering at least a portion of said pole core.

10. A mosaic print head comprising a housing having a needle guide with a lower print head guide and an upper guide portion, a plurality of needles engaged with said lower print head guide and said upper guide portion and being disposed for vertical axial movement, a plurality of electromagnets arranged around said needles each having a pole core and an armature movable relative to said pole core having a first end movable toward and away from said pole core and an opposite second end, means pivotally supporting'said opposite second end of said armature located radially outwardly of said core, and a leaf spring having a first end supported between said first end of said armature and said pole core and having a second end engaged with a respective needle, said leaf spring comprising a continuous member having comb-like fingers with a respective finger engaging respective needle.

Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3904011 *Oct 17, 1973Sep 9, 1975Tele Speed Communications IncPrinting head for matrix printer
US3929214 *Sep 18, 1974Dec 30, 1975D & D AssWire matrix ballistic impact print head
US3963108 *May 20, 1974Jun 15, 1976Veb Kombinat Zentronik Sommerda/ThMatrix printing head
US3968867 *Jul 15, 1974Jul 13, 1976Facit AktiebolagInformation transmission device for point contact on an information carrier
US3973661 *May 8, 1974Aug 10, 1976Teletype CorporationWire-matrix printers, and electromagnetic actuator mechanisms useful in such printers
US3982622 *Oct 4, 1974Sep 28, 1976Teletype CorporationActuator mechanisms for wire matrix printers
US3994381 *Apr 23, 1975Nov 30, 1976The Singer CompanyWire matrix print head
US4000801 *Nov 10, 1975Jan 4, 1977International Business Machines CorporationPrint wire attachment
US4009772 *Aug 19, 1974Mar 1, 1977Steinmetz Krischke Systemtechnik GmbhMosaic printing head
US4049107 *Oct 3, 1975Sep 20, 1977Societe D'applications Generales D'electricite Et De Mecanique SagemPrinting devices or heads for printers or the like and a process for making such a printing head
US4051941 *Jun 28, 1976Oct 4, 1977Xerox CorporationMatrix print head with improved armature retainer
US4155660 *Mar 10, 1977May 22, 1979Pilot Man-Nen-Hitsu Kabushiki KaishaDot printing wire
US4176975 *Dec 5, 1977Dec 4, 1979International Business Machines CorporationMetalloid filament wire matrix print head
US4197021 *May 11, 1978Apr 8, 1980Kabushiki Kaisha Suwa SeikoshaPrinting head for a wire-type dot printer
US4222674 *May 11, 1978Sep 16, 1980Kabushiki Kaisha Suwa SeikoshaHead portion of a dot printer
US4229114 *Feb 12, 1979Oct 21, 1980Dataproducts CorporationMechanism for operator-replaceable printhead
US4230038 *Jun 23, 1977Oct 28, 1980Helmut FalkMatrix print head assembly
US4240756 *Jul 26, 1978Dec 23, 1980Ku Joseph POptimized wire matrix impact print head
US4252449 *May 11, 1979Feb 24, 1981Shinshu Seiki Kabushiki KaishaConstruction of wire type dot printer head
US4317635 *Feb 7, 1980Mar 2, 1982Svenska Kassaprinter AbMatrix printing head
US4368353 *Mar 6, 1981Jan 11, 1983Oki Electric Industry Co., Ltd.Printer head for serial dot printer
US4393771 *Nov 24, 1981Jul 19, 1983Ye Data Inc.Printing head for a printer
US4403874 *Mar 25, 1980Sep 13, 1983Ramtek CorporationColor printer and multi-ribbon cartridge therefor
US4561790 *Jan 28, 1985Dec 31, 1985International Business Machines CorporationWire matrix print head apparatus
US4648730 *Mar 18, 1986Mar 10, 1987Honeywell Information Systems ItaliaArmature group for mosaic printing head and related manufacturing method
US4650353 *May 24, 1982Mar 17, 1987Gte Products CorporationPrinter wire
US4687355 *Sep 24, 1985Aug 18, 1987Citizen Watch Co., Ltd.Printing head for use in dot printers
US4750259 *Sep 24, 1986Jun 14, 1988Honeywell Bull Italia S.P.A.Method of making armature group for mosaic printing head
US4832515 *Jul 23, 1987May 23, 1989Kabushiki Kaisha ToshibaPrinting head for a wire dot-matrix printer
US4844634 *May 16, 1988Jul 4, 1989Ye Data Inc.Printing head for an impact printer
US4884905 *Feb 19, 1988Dec 5, 1989International Business Machines CorporationPrint head incorporating one piece armature with intermediate clamping pads
EP0107965A2 *Oct 25, 1983May 9, 1984Royden C. Sanders, Jr.Dot matrix printers and print head therefor
EP0107965A3 *Oct 25, 1983Oct 16, 1985John L. ForsythDot matrix printers and print head therefor
EP0322991A1 *Jan 4, 1988Jul 5, 1989Oki Electric Industry Company, LimitedWire dot print head
Classifications
U.S. Classification400/124.18, 101/93, 400/124.32, 101/93.5, 335/274
International ClassificationB41J2/25, G06K15/02, B41J2/27, B41J1/00, B41J2/26, G06K15/10, B41J1/08, B41J2/275
Cooperative ClassificationB41J2/275
European ClassificationB41J2/275