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Publication numberUS3605611 A
Publication typeGrant
Publication dateSep 20, 1971
Filing dateMay 8, 1969
Priority dateMay 8, 1969
Also published asDE2022618A1
Publication numberUS 3605611 A, US 3605611A, US-A-3605611, US3605611 A, US3605611A
InventorsKonkel Joseph, Schaller Frank H
Original AssigneeData Printer Corp
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Print hammer and actuator construction for high speed printers
US 3605611 A
Abstract  available in
Images(2)
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Claims  available in
Description  (OCR text may contain errors)

Sept? 20, 1971 J. KONKEL L 3,605,511

PRINT HAMMER AND ACTUATOR CONSTRUCTION FOR HIGH SPEED PRINTERS Filed Ra 8, 1969 2 Sheets-Sheet 1 INVENTORS F JOSEPH KONKEL FRANK H. SCHALLER ATTORNEYS Sept. 20, 1971 J. QNK EIAL PRINT HAMMER AND ACTUATOR CONSTRUCTION FOR HIGH SPEED PRINTERS Filed May 8, 1969 2 Sheets-Sheet 2 v Qk lNVfA/TORS JOSEPH KONKEL FRANK H. SCHALLER BY ZMW ATTORNEYS United States Patent ()ifice 3,605,611 Patented Sept. 20, 1971 3,605,611 PRINT HAMMER AND ACTUATOR CONSTRUC- TION FOR HIGH SPEED PRINTERS Joseph Konkel and Frank H. Schaller, Lynnfield, Mass., assignors to Data Printer Corp., Boston, Mass. Filed May 8, 1969, Ser. No. 822,985 Int. Cl. B41j 9/02; H01f 7/14 US. Cl. 101-93C 14 Claims ABSTRACT OF THE DISCLOSURE Our invention relates to high speed printers, and particularly to a novel hammer actuator construction.

High speed printers of the line at a time type have long been known in the art, and have reached a high state of development. Such printers are commonly used at line rates of 200 to 1200 per minute. Since the usual character spacing required is on the order of per inch, print hammer actuating mechanisms of considerable complexity have evolved in an effort to make maximum utilization of the space surrounding the print hammers, while dissipating the relatively large amount of energy required for printing. In general, electromagnetic actuators have been used, in which a pulse of current is applied to a coil to attract an armature and move the print hammer, either directly or through an intermediate hammer actuator, to cause the hammer to strike against the paper, ribbon and type carrier. In order to make the necessary amount of mechanical energy available in an actuator of this kind, it has been the practice to incorporate the electromagnetic drive structure for a number of columns in a composite module. Commonly, modules of either four or six hammers or hammer actuators have been employed. Such modules usually include a combination of geometrically complementary actuators, one having an actuating arm extending directly away from the armature, and another having an actuating arm at 90 to the armature, together with a combination core construction in which several electromagnetic elements are interlocked in a single block. The resultant structure is relatively efi'icient, and thousands of printers incorporating such modules have been made and used. However, not only is the manufacture and assembly of each module a complex procedure, but the completed modules require individual positioning relative to the line of print, and adjustment and maintenance are difficult and time consuming. The objects of our invention are to simplify the construction of high speed printers and to facilitate their manufacture, adjustment and maintenance.

The above and other objects of our invention are obtained by a novel print hammer actuator construction wherein each print hammer actuator is independent of the others but in which means are provided for aligning them in groups when they are installed, whereby an individual actuator can be removed for replacement or service, but in which large numbers of actuators are aligned at the same time.

Briefly, a print hammer actuator assembly constructed in accordance with our invention comprises, on either side of the line of print, and below a bank of print hammers, an outer bank of hammer actuators each comprising an electromagnetic core with an armature pivotally attached thereto and carrying an actuator arm that extends inward towards the line of print into engagement with one of the bank of hammers arranged below the line of print. The hammers are suspended by a pair of leaf springs from a support bar that extends over the actuator assembly. Within each outer bank of actuators is an inner bank of actuators, on either side of the line of print, comprising an electromagnetic core assembly that is the same shape as the core assemblies of the outer bank except that it is rotated by Each actuator of the inner bank further comprises an armature connected to an actuator arm at 90, which actuator arm engages a hammer displaced by two columns from the hammer associated with the adjacent actuators of the outer bank. A pair of alignment combs are disposed on either side of the line of print, each notched to received alternate actuating arms of the inner and outer banks of that side, and maintain the actuator arms in columnar alignment with the hammers with which they are associated. Inside each alignment comb, and spaced on either side of the line of print, are a bank of independently adjustable bottom stops engaging each actuator arm. For each of the outer and inner banks of actuators, there is provided a transverse alignment comb that when mounted to the actuator base plate 10- cates all of the actuators of the bank in directions parallel to the line of print. Also, for each bank of actuators there is a single stop plate that aligns all the actuators of that bank in a direction normal to the line of print. The result is a construction in which the alignment of all of the actuators is established before any actuator is installed. Any actuator of an outer bank can be removed without affecting the alignment of the others, and, surprisingly, any actuator of an inner bank can also be so removed, by withdrawing it obliquely upwardly toward the line of print.

Our invention will best be understood in the light of the following detailed description, together with the accompanying drawings, of a preferred embodiment thereof.

In the drawings:

FIG. 1 is a schematic plan view, with parts shown in cross-section and parts broken away, of a print hammer and actuator assembly in accordance with our invention;

FIG. 2 is a schematic cross-sectional view, taken essentially along the lines 22 in FIG. 1;

FIG. 3 is an elevational view of a detail of FIG. 2, taken substantially along the lines 33 in FIG. 2, with the actuator arm omitted;

FIG. 4 is a schematic perspective sketch of one of the actuator arms and armatures of the apparatus in FIGS. 1 and 2;

FIG. 5 is a schematic perspective sketch of a portion of the alignment comb and stop assembly forming a part of the apparatus of FIGS. 1 and 2.

Referring now to FIGS. 1 and 2, the apparatus of our invention comprises an actuator base plate 1, formed at the sides with a pair of elongated apertures 2 and with a central aperture 3. As shown in FIG. 2, the base plate 1 is secured to a relatively massive cast iron base frame 4 by a suitable conventional means, such as the bolts 5 and 6. Preferably, the actuator base plate 1 is located on the frame 4 by dowels in the frame, with the bolts such as 5 and 6 passing through clearance holes so that they serve to secure the actuator base plate to the frame, but do not interfere with the location of the frame relative to the plate by means of the dowels.

A pair of brackets 7 and 8 are secured to the plate 1 at either end, as shown in FIG. 1, and support a transverse bar 9, shown fragmentarily in FIG. 1 and in crosssection in FIG. 2, that serves as the main support for the print hammers. The print hammers are preferably of the form shown in FIG. 2, and are each supported by a pair of leaf springs 11 and 12. The springs 11 and 12 are in turn secured to a channel 13.

The channel 13 is located on the beam 9 by suitable means, such as a dowel, not shown, and a shoulder screw 14, that serves as a removable dowel. Conventional fasteners, such as bolts, not shown, serve to secure the channel to the beam.

As best shown in FIG. 1, the hammer support springs, such as the upper springs 11, are arranged in complementary pairs such as 11a and 11b so that each pair can be secured by a single bolt 15. The lower springs 12 are similarly arranged to be secured in pairs by bolts 16.

The hammers are each arranged to be actuated by a different one of a set of actuators. The actuators are divided into an inner group, comprising actuators such as that shown at 17 in FIG. '2, and an outer group, comprising actuators such as that shown at 18 in FIG. 2.

As will appear, the actuators 17 and 18 are mechanically equivalent, but are of complementary form to enable them to be assembled in closely adjacent relationship. Each actuator comprises a core, an electromagnetic coil wound on the core, an armature, and an actuator arm connected to the armature and pivoted to the core.

Specifically, each actuator 17 comprises a core member 19 formed with a slot as indicated at 20 to provide a core arm 21 on which is wound an electromagnetic coil 22. As shown, the core 19 is secured to the actuator base plate 1 by means of a bolt such as 23 so that part of the coil 22 extends down through the aperture 2 in the plate 1. A pair of cars 24 are formed on the core 19 to anchor a pivot pin 25 that serves to mount an actuator arm 27, for the actuators 17, or a corresponding actuator arm 28 for the actuators 1 8.

The actuator arms such as 27 are connected to an armature 29 that extends at right angles to the actuator arm 27. The actuator arms 28 are connected to geometrically similar armatures 30 that are in alignment with the arms 28.

As best shown in FIGS. 3 and 4, the pivot pins 25 cooperate with suitable bearings 31 mounted in the actuator arms such as 28. Similar bearings are provided in the arms 27.

The outer actuators 18 are secured to the base plate 1 by means of bolts such as 32 extending parallel to the core arms 20. It will be apparent that the cores 19 and 19a of the separate forms 17 and 18 are identical, except that one is rotated 90 with respect to the other, and the corresponding threaded mounting hole similarly displaced. The mounting bolts 23 and 32 extend through clearance holes in the base plate 1 so that they do not serve to locate the actuators 17 or 18, but merly to hold them down after they have been located. Positioning of the actuators is accomplished by a series of locating combs and stop plates, next to be described.

An important advantage of the actuator construction just described is that the armatures 29 and 30 extend over a portion of the ears 24. The ears thus form a part of the magnetic circuit. To permit that result, the ends of the core legs 20 and 21 are flat and coplanar with the corresponding ends of the ears 24. And the pivot pins 25 are located below the common plane of those ends of the core legs and ears.

Referring to FIGS. 1 and 2, four identical actuator alignment combs 33 are each provided with a series of recesses such as 34 that serve to locate the actuators 17 and 18 in directions parallel to the line of print. At the rear of each alignment comb, and located above it, is a stop bar 35, shown in fragmentary form over the first and third combs from left to right in FIG. 1, in full for thesecond comb and omitted for the fourth comb. The edges of these stop bars 35 locate the actuators 17 and 18 in directions normal to the line of print. The bars are positioned by locating holes 37, as shown at the upper.

right in FIG. 1, and by a lower aperture 38 that is elongated in a direction parallel to the line of print.

In accordance with our invention in its broader aspects, the stop bars 35 could be omitted and their function performed by the inner edges of the spaces between the teeth of the combs 33. That would compli cate the manufacture of the combs, however, and we prefer the construction shown.

The apertures 37 and 38 are adapted to receive dowel pins secured to the base plate 1. The dowel pins are precisely located, and the elongation provided for the lower aperture 38 is to account for minor changes in dimension lengthwise of the combs 33 without allowing any movement of the combs angularly with respect to the line of print. Similarly, the stop bars 35 are provided with apertures 39, as shown at the upper left in FIG. 1, and elongated apertures 40 at the other end, to accurately position the stop bars on the dowel pins such as 41. The stop bars 35 and combs 38 may be firmly secured to the base frame 4 by means such as the bolts 42 extending through clearance holes such as 43 in the comb, stop bars, and base plate 1.

[For clarity, FIG. 2 shows only one inner actuator assembly 17 and one outer actuator assembly 18 located on d'nferent sides of the line of print. In practice, an inner set of actuators 17 will be located on the left side in FIG. 2, and an outer set such as 1-8 will be located on the outer side at the right in FIG. 2. The pivot pins 25 for each of the mating units 17 and 18 on a given side of the line of print will be in axial alignment in a line parallel to the line of print. The exact arrangement is shown in FIG. 1, for the central group of four actuators, showing how they are arranged side by side.

The dimensions of the parts in directions parallel to the line of print is determined by the character spacing in the printer. Thus, if the characters are to be printed on onetenth inch centers, the width of one column is one-tenth. of an inch and the thickness of the actuator core assemblies will be two columns wide, or two-tenths of an inch. The teeth 34 of the combs 33 will be two columns wide with two column spaces between teeth. Confronting combs are relatively displaced by two columns, and corresponding combs on opposite sides of the line of print, such as those locating the outer actuator 18, are displaced by one column. The result is that the actuating arms of the print hammer actuators are interdigitated in the order shown in FIG. 1.

It will be apparent by comparing FIGS. 1 and 2 that the only overlap in the actuators 17 and 18 is in the coils 22 of the inner actuators 17 that extend under the corresponding adjacent actuators 18 with clearance. The arrangement is such that any of the actuators 17 and 18 can be removed individually.

The actuator arms 27 for the actuators such as 17 have a slight net clockwise moment, as seen in FIG. 2, by reason of the additional weight of the armature portion 29. In the rest position, each such arm 27 is held down against a resilient stop pad 47 that is mounted on a stop comb 48. As best shown in FIG. 5, the stop comb 38 comprises a flange portion 49 arranged to be bolted to a screw plate 50. The screw plate 50 extends lengthwise across the base plate 1 in a direction parallel to the line of print, as shown in FIG. 1. Referring again to FIG. 5, an upstanding portion 51 of the stop comb is formed with laterally projecting teeth 58, on each of which a stop pad 47 is mounted. The pads may be of rubber or the like. Mounted with each of the stop combs 48 is an alignment comb 53 provided with upstanding teeth 54 that separate and guide the actuator arms such as 2-7 and 28.

The springs 11 and 12 mounting each hammer 10 hold the associated actuator arm such as 27 and 28 down against the stop pads 47 until the hammer actuator is energized by application of a pulse of current to its asso ciated coil 22. When that occurs, the armature such as 29 of the actuator such as 17 is drawn toward the core arm 21, causing the actuator 27 to rise and drive the associated hammer upwardly, to contact with the paper, transfer sheet and moving type carrier to form an impression.

Flight time adjustment of the hammers 10 is accomplished by adjustment of the bottom stops 47 on the stop combs 48. For that purpose, screws 57 are threadedly secured to the base plate 50 and engage the individual teeth of the stop comb 48 so that individual adjustment for each column can be provided.

While we have described our invention with respect to the details of a preferred embodiment thereof, many changes and variations will occur to those skilled in the art upon reading our description, and such can obviously be made without departing from the scope of our invention.

Having thus described our invention, what we claim 1. A hammer actuator assembly for high speed printers, comprising:

an actuator mounting plate, an alignment comb secured to said plate and having a base portion and teeth projecting from said base portion, said teeth having parallel sides extending along lines normal to a predetermined plane,

a stop bar secured to said mounting plate adjacent said comb and having an edge normal to said sides, and

a set of actuators,

means for removably securing each actuator to said plate between respective teeth of said comb,

each of said actuators cooperating with a respective hammer,

each actuator having two sides engaging said teeth and held in alignment thereby, and

a third side engaging said edge of said stop bar to establish lateral alignment of said actuators, said stop bar cooperating with said securing means to prevent lateral movement of said actuators, whereby the alignment of said actuators is determined by the respective positions of said comb and stop bar on said plate.

2. The apparatus of claim 1, in which said actuator each comprise:

a ferromagnetic core on which a coil adapted to be energized by a pulse of current is wound, an actuator arm pivotally mounted on said core, and an armature connected to said arm in position to be attracted to said core when coil is energized. 3. The apparatus of claim 2 in which the cores of said actuators on a first side of said recess comprise:

core legs on which said coils are wound about axes normal to said plate, in which the cores of said actuator on the other side of said recess comprise core legs on which said coils are wound about axes parallel to said plate, the coils on said other side partially protruding through said recess.

4. The apparatus of claim 2 in which all of said actuator arms are pivoted about a common axis,

in which the armatures on said first side are aligned with the actuator arms to which they are connected, and

in which the armatures on said other side extend at right angles to the actuator arms to which they are connected.

5. A hammer actuator for a high speed printer, comprising:

a core piece of ferromagnetic material formed with a core leg on a first side thereof and an electromagnetic coil wound on said core leg about a first axis,

a pair of parallel ears extending from said core piece in planes parallel to said first axis,

a pivot pin mounted between said ears and defining a pivot axis normal to said plane,

an actuator arm for cooperating with a print hammer pivotally mounted on said pin, and

an armature block of ferromagnetic material connected to said actuator arm and extending over a portion of said ears and said core leg to be attracted toward said core leg when said coil is energized, said ears forming a part of the magnetic circuit comprising said armature and ferromagnetic core piece.

6. The actuator of claim 5 in which said core piece terminates in a flat end,

said ears terminate in flat ends substantially coplanar with said end of said core piece, and

said pivot pin is located below the plane of said ends.

7. The actuator of claim 5 in which said actuator arm extends to an actuating end along a line in alignment with said armature, and further comprising:

means forming a threaded mounting recess in said core piece normal to said first axis. 9. The actuator of claim '5 in which the maximum dimension of the recited elements other than said coil in directions parallel to said pivot axis is the width of two columns in the printer in which the actuator is to be installed.

10. The actuator of claim -6 in which said actuator arm extends to an actuating end along a line in alignment with said armature, and further comprising:

means forming a threaded mounting recess in said core piece parallel to said first axis.

11. The actuator of claim 6 in which said actuator arm extends to an actuating end along a line normal to the extension of said armature, and further comprising:

means forming a threaded mounting recess in said core piece normal to said first axis.

12. The actuator of claim 6 in which the maximum dimension of the recited elements other than said coil in directions parallel to said pivot axis is the width of two columns in the printer in which the actuator is to be installed.

13. A print hammer actuator assembly, comprising:

a pair of alignment combs each having projecting teeth two columns wide interspersed with spaces two columns wide.

means mounting said combs in spaced confronting relation with the teeth of one comb projecting toward the spaces between the teeth of the other comb,

a pair of stop bars each having at least one straight edge,

means mounting each of said stop bars against one of said combs with said edge across said teeth,

a set of electromagnetic hammer actuating means, one for each space between comb teeth,

means detachably mounting said actuating means between and engaging different pairs of said teeth of each of said combs and engaging said edge of one of said stop bars, said actuating means comprising core pieces extending between said teeth end having actuating arms pivotally mounted thereon for rotation about first axes parallel to said edges, and

armatures connected to said arms and adapted to be moved toward and away from said core pieces upon rotation of said arms,

said core pieces, arms and armatures having maximum dimensions in directions parallel to said pivot axes not greater than the width of two columns,

the core pieces located between the teeth of one comb projecting toward and into interdigitated relation with the actuators located between the teeth of the other comb and the pivot axes of all of said actuators being colinear,

said core pieces being formed with core legs,

the core legs of the core pieces engaging one comb being located on the side away from the other comb, and the core legs on the core pieces engaging the other comb being formed on the side of the core piece next to the comb and extending toward the other comb and beneath said colinear pivot axes, and

electromagnetic coils having maximum dimensions not larger than twocolumns in directions parallel to said axes Wound on all of said core legs.

14. A hammer actuator assembly for high speed printers, of the line at a time type including a moving type carrier and independent, selectively actuable hammer actuators, one for each of a plurality of columns in a line to be printed, comprising:

an actuator mounting plate,

an alignment comb secured to said plate and having a base portion and teeth projecting from said base portion, said teeth having parallel sides forming locating surfaces extending normal to the plane of said mounting plate,

a stop bar secured to said mounting plate adjacent said comb and having an edge normal to said surfaces, and

a set of selectively and independently energizable ferromagnetic actuator elements, individual detachable means for each actuator element for fixedly mounting each actuator element on said plate, each ac- 30 tuator element being detachably mounted between diiferent teeth of said comb, means for selectively energizing each of said actuator elements, each mounted on said plate between different teeth of said comb,

each actuator element having two sides engaging a corresponding pair of said locating surfaces and held in alignment therebetween, and

a third side engaging said edge of said stop bar to prevent lateral movement of said actuator elements, whereby said actuator elements are each independently, selectively actuable and the alignment of each of said actuator elements is independently determined by the relative positions of said comb, said stop bar and said plate.

References Cited UNITED STATES PATENTS WILLIAM B. PENN, Primary Examiner E. M. COVEN, Assistant Examiner US. Cl. X.R.

Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3780650 *Dec 20, 1971Dec 25, 1973IbmPrint hammer with moving coil
US3805695 *Sep 18, 1972Apr 23, 1974Teletype CorpArmature mounting assembly for a teleprinter
US3919933 *Oct 5, 1973Nov 18, 1975Potter Instrument Co IncHigh speed printer
US3951061 *May 17, 1974Apr 20, 1976Custom Printers, Inc.Label printing apparatus
US4004507 *May 24, 1976Jan 25, 1977Hotchkiss Brandt SogemeEnvelope indexing head and an indexing apparatus equipped with same
US4033256 *May 9, 1975Jul 5, 1977Kabushiki Kaisha Suwa SeikoshaPrinter
US4075943 *Oct 21, 1975Feb 28, 1978Sperry Rand CorporationHigh speed actuator for impact line printers
US4164180 *Sep 29, 1977Aug 14, 1979Interface Mechanisms, Inc.Impact printer including hammer bank assembly
US4164181 *Jul 1, 1977Aug 14, 1979Kabushiki Kaisha Suwa SeikoshaPrinter
US4395945 *Sep 3, 1981Aug 2, 1983Dataproducts CorporationHammer bank assembly
Classifications
U.S. Classification101/93.33, 335/276, 101/93.48
International ClassificationB41J9/00, B41J9/10
Cooperative ClassificationB41J9/10
European ClassificationB41J9/10