CA1096234A - Wear minimizing means for printing mechanism - Google Patents
Wear minimizing means for printing mechanismInfo
- Publication number
- CA1096234A CA1096234A CA303,260A CA303260A CA1096234A CA 1096234 A CA1096234 A CA 1096234A CA 303260 A CA303260 A CA 303260A CA 1096234 A CA1096234 A CA 1096234A
- Authority
- CA
- Canada
- Prior art keywords
- printing
- support member
- end bearing
- element receiving
- receiving apertures
- 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
Links
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
- B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
- B41J2/22—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by selective application of impact or pressure on a printing material or impression-transfer material
- B41J2/23—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by selective application of impact or pressure on a printing material or impression-transfer material using print wires
- B41J2/235—Print head assemblies
- B41J2/265—Guides for print wires
-
- 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
- B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
- B41J2/22—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by selective application of impact or pressure on a printing material or impression-transfer material
- B41J2/23—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by selective application of impact or pressure on a printing material or impression-transfer material using print wires
- B41J2/235—Print head assemblies
- B41J2/25—Print wires
- B41J2/255—Arrangement of the print ends of the wires
Landscapes
- Impact Printers (AREA)
- Character Spaces And Line Spaces In Printers (AREA)
Abstract
Docket No. 2581 Title of the Invention WEAR MINIMIZING MEANS FOR PRINTING MECHANISM
Abstract of the Disclosure In a matrix print head, a plurality of elongated printing elements, mounted in a frame, are driven axially by electromagnetic means to effect printing on record media positioned adjacent to the printing ends of the printing elements. Print element support means mounted within the frame route the printing elements so that their axes are essentially in the same plane and parallel to each other during a portion of their passage through the frame in order to eliminate side loading of the printing elements by the tip bearing of the matrix print head.
Abstract of the Disclosure In a matrix print head, a plurality of elongated printing elements, mounted in a frame, are driven axially by electromagnetic means to effect printing on record media positioned adjacent to the printing ends of the printing elements. Print element support means mounted within the frame route the printing elements so that their axes are essentially in the same plane and parallel to each other during a portion of their passage through the frame in order to eliminate side loading of the printing elements by the tip bearing of the matrix print head.
Description
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Background of the Invention In the field of high-speed printing devices which are especially suitable for use in connection with electronic data processing systems, the wire matrix type of printer has come into increasing use. In this type of printer, letters, numbers and symbols are formed from a series of dots produced by the impact of the ends of a plurality of wire elements on record media, most customarily in combination with an ink ribbon which provides the ink needed to produce a mark on the record media being printed upon.
One problem which has arisen in connection with use o printers of the wire matrix type is that of wear of the tip bearing which is located near the printing end of the matrix printer and through which the print wires extend and from which they protrude when in printing position. In order to reduce or eliminate such wear, various means have been employed in prior art structures, such as the use of tip bear-ings made of synthetic sapphire or other very hard materials to limit tip bearing wear. However, this method is quite costly and results in e~cessive wear of the print wires. In another prior art'structure, means are provided for lubricating the wires where they pass through the bearing. However, this introduces an additional element into the structure, increasing the cost and complexity of the assembly, and also results in inconvenience in the necessity for periodic replenishment of the lubricant.
Summary of the Inventio This invention reIates to a printer of khe matrix type, and more particularly relates to such a prinker which includes means for reducing wear of the ~rinter kip bearing.
33~
Background of the Invention In the field of high-speed printing devices which are especially suitable for use in connection with electronic data processing systems, the wire matrix type of printer has come into increasing use. In this type of printer, letters, numbers and symbols are formed from a series of dots produced by the impact of the ends of a plurality of wire elements on record media, most customarily in combination with an ink ribbon which provides the ink needed to produce a mark on the record media being printed upon.
One problem which has arisen in connection with use o printers of the wire matrix type is that of wear of the tip bearing which is located near the printing end of the matrix printer and through which the print wires extend and from which they protrude when in printing position. In order to reduce or eliminate such wear, various means have been employed in prior art structures, such as the use of tip bear-ings made of synthetic sapphire or other very hard materials to limit tip bearing wear. However, this method is quite costly and results in e~cessive wear of the print wires. In another prior art'structure, means are provided for lubricating the wires where they pass through the bearing. However, this introduces an additional element into the structure, increasing the cost and complexity of the assembly, and also results in inconvenience in the necessity for periodic replenishment of the lubricant.
Summary of the Inventio This invention reIates to a printer of khe matrix type, and more particularly relates to such a prinker which includes means for reducing wear of the ~rinter kip bearing.
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3~
In accordance with one embodiment of the invention, a printing mechanism for printing on record media comprises frame means including an end bearing means having a plurality of printing element receiving apertures disposed therein; a plu-rality of support members mounted on said frame means including a first support member located closest to the end bearing means, spaced therefrom, and having a plurality of printing element receiving apertures disposed therein; a plurality of printing elements extending through said support members and capable of being driven to effect printing, said support members causing said printing elements to be positioned in paths which are sub-stantially in parallel relation to the longitudinal axis of the frame means between said first support member and said end bearing means.
It is accordingly an object of the present invention to provide a print head which includes means for reducing wear of the printer tip bearing.
Another object is to provide a print head having printing element support members configured to constrain the paths of movement of the printing elements adjac~nt to the print tip bearing means to a direction substantially perpendic-ular to the direction of relative movement between the prin-t head and the record media being printed upon, in order to sub-stantially eliminate side loading on said print tip bearing means.~
A further object is to provide a print head which is durable and reliable in operation.
With these and other objects, which will be apparent from the following descriptionr in view, thé invention includes certain noveI features of construction and combinations of parts, one form of embodiment of which is hereinafter described with reference to the drawings which accompany and form a part of this specification.
Brief Description of the Drawings Fig. l is a sectional view of a print head in accor-dance with the present invention;
Fig. 2 is an elevation view, partly broken away, showing the frame and the elongated printing elements of the print head;
Fig. 3 is an enlarged cross sectional view taken along line 3-3 o Fig. 2; and Fig. ~ is an enlarged cross-sectional view taken along line 4-4 of Fig. 2; and Fig. 5 is an enlarged cross-sectional view taken along line 5-5 of Fig. 2; and Fig. 6 is an enlarged cross-sectional view taken along line ~-6 of Fig. 2; and Fig. 7 i5 a bottom view of the frame of Fig. 2, ta~en along line 7-7, showing the tip bearing; and Figs. 8A to 8E inclusive are enlarged partial section-al views showing the printing end o the print head and illustra-ting the manner in which an elongated printing element coacts with the tip bearing under various conditions.
Description of the Preferred Embodiment Reerring now particularly to Fig. l of the drawings, a print head 10 of the wire matrix type is shown. This print ; head is similar in general configuration to the print head dis-closed in United States Patent No. 3,929,214, issued December 30, 1975, to which reference ma~ be had for a more detailed description of certain aspects of the print head 3~:
structure.
A frame 12 is provided to support a plurality of elongated print elements or print wires 14, onl~ two of which are shown, for purposes of simplification and ready understand-ing of the drawings. Each wire 14 has a cap 16 which may be made of plastic or other suitable material, attached to its impact-receiving end to enlarge the area of the impact-receiving surface. Each wire 14 also has a spring 18 disposed at its upper end, which exerts a force upon the cap 1~ to re-siliently bias the wire relative to the frame 12. The spring18 has been omitted from one of the wires of Fig. l, in order that the cap 16 may be more clearly depicted.
The frame 12 includes three side walls 20, 22) 24, a print end member 25 (also shown in Fig. 7) and an upper end member 26 (also shown in Fig. 3). A first print wire support member or bridge 27 (also shown in Fig. 6) is loosely mounted in grooves in the walls 20, 22, 24 close to the print end mem-ber 25, to permit the member 27 to shift laterally with respect to the frame in a plane substantialIy perpendicular to the longitudinal a~is of the frame, and which is parallel to the direction of relative movement between the print head lO and the record media which is to be printed upon by said print head. Two intermediate support members or bridges 28 (also shown in Fig. 5) and 29 (also shown in Fig. 4) are positioned in grooves in the side walls 20, 22 in planes parallel to the plane of the support member 27. The support members 28 and 29 are not intended to move laterally with respect to the rame, and thus fit relatively tightly within their respective grooves.
The members 26, 27, 28, 29 constrain the various 3~L
print wires 14 in predetermined paths, and accomplish the translation of the wires from a generally circular formation at the left end as seen in Fig. 1 to a linear formation at the printing end, and also cause the print wires to move into an essentially planar relationship perpendicular to the direction of relative movement between the record media and the print head, becoming substantially coincident with a plane through the center line of the print head at a point slightly to the left of the member 27, as seen in Fig. 1, and to continue in such planar relationship through the member 27 and the bearing 36 positioned in the pri~t end member 25. The translation is accomplished by passing each wire 14 through a separate hole 30 in the upper end member 26, through similar holes 31, 32, 33 in the members 29, 28, 27 and into a defined position in the bearing 36. The members 27, 28, 29 and the apertures therein are positioned so that the paths of movement of the wires 14 are completely determined thereby. Thus, theoretic-ally, the apertures in the end bearing 36 do not determine the paths of the wires 14 therethrough r and there would be no side loading whatever of the wires thereby. Actually, there may be some slight devlation Erom the ideal plotted paths of the wires 14, and thus some slight side loading.
The bearing 36 is of a material which resists wear and has a low coefficient of friction.
~ pair of mounting flanges 38 and 40 extend laterally from the upper ends of sidewalls 20 and 22. The frame 12 is circular in cross-sectional shape to the left of flanges 38, 40 as seen in Fi~. 1, and terminates in the upper end support member 26 which is of circular configuration. An apertured post 42 e~tends from the member 26 and pro~ides means for assembling the driving means for the wires 14 to the frame 12, as will subsequently be described in greater detail.
As shown in Fig. 1, a plate 44 is provided with a central aperture 46 and is secured to the flanges 38, 40 on the frame 12 by suitable fastening means 48. The circular portion of the frame 12 extends through the aperture 46. A
plurality of holes 50 are provided in the plate 44 for mounting a corresponding plurality, nine in the illustrated embodiment, of actuating means for the wire printing elements 14.
A coil 52, a center pole S4, an "L" shaped outer pole 56 and an armature 58 form the electromagnetic actuating means used in the print head. An armature shim 59 spaces the armatures 58 away from the poles 54 for the purpose of effect-ing faster armature release. A bore 60 is provided in the horizontal leg of the "L" shaped outer pole 56 for receiving the lower extremity of the center pole 54O
A unitary connector 62 is mounted by means of a screw 64 and a washer 66 to the post 42 of the frame 12. The connec-tor 62 has a circular central portion 68 with an annular groove 70 provided in its bottom surface. An 0-ring 72 is inserted in the groove 70 to act as a shock absor~er and to provide a ref-erence surface for the cap 16 of the print wire 14 striking the end of the armature 58. Nine arms 74 are formed integral with the central portion 68 of the connector 62 and extend therefrom.
~ach arm 74 has associated with it a first armature receiving structure 76 and~a second armature receiviny structure 78~ One end of each armature 58 is received and held in place by the structure 76 and the other end of each armature i6 received and guided by the structure 7~. With the connector 62 installed in the position shown, the arras 74 apply forces to the cantilevered distal ends of the armatures, causing their print wire irnpacting ends to rotate about the fulcrum formed by the top edge of the pole 56 and upwardly into ~ngagement with the 0-ring 72. The caps 16 associated with the prin-t wires 14 are maintained in contact with the ends of the armature 58 by means of the forces applied by the springs 18.
As discussed in greater detail in the previously-cited United States Patent No. 3,929,214, the unitary connec-tor 62 serves a number of functions in the assembly and opera-tion of the print head 10, including retaining the armatures 58 in proper relationship to the remainder of the structure, acting as a biasing means for the armatures, providing means for adjusting the air gap between the armatures 58 and the corresponding center poles 52~ forming a reference surface for the armatures 58 and print wire caps 16, to assure that all actuated print wires 14 impact the record medium at substantially the same time during a printing cycle, and, by means of 0-ring 72, absorbing energy from the armatures ~8 and the print wires 14 on return motion after actuation.
As is also described in gxeater detail in the previ-ously-mentioned United States Patent No. 3,929~214, characters such as numbers, letters or symbols are generated by the print head by a sequence of print cycles. Selective actuation of predetermined combinations of print wires 14 through energiza-tion of their corresponding coils 52 during each cycle results in the formation of the desired character on the record medium, with the print head being shifted one position with respect to the record medium after each cycle to be properly located for the next printing cycle.
When a coil 52 is energized, a magnetic flux is created ~hich causes armature 58 to be drawn into contact with ; - 8 -~6~
center pole 59. The movement of armature 58 transmits ener~y into print wire 14, causing i~ to move in an axial direction in the ~rame 12. The force imparted into the wire 14 causes it to move against the spring 18 and its inertia causes it to contin-ue to move downwardly out of contact with the armature 58 after said armature bottoms out against the center pole 54. The impact-delivering end of the print wire 14 extends beyond bear-ing 36 and strikes the record medium, causing a dot to be im-printed. The energy stored in the moving print wire 14 is partially absorbed by the impacted record medium and is par~
tially returned to the print wire 14, aiding the spring 18 in returning the print wire 14 to its rest position.
At approximately the same time that the print wire 14 is impacting the record medium, the coil 52 is deenergized~
The movement exerted on the armature 58 by the arm 74 causes it to rotate away from the center pole 5~ and to return into contact with the 0-ring 72.
Examination of the curved path of movement of a typi-cal print wire above the tip bearing in a conventional matrix print head, such as that disclosed in the previously-cited United States Patent No. 3,929,214, discloses that the tip bearing, such as a bearing 100 of a print head 102, shown in a new, unused condition in Fig. 8A must supply a side load to the print wire 104 in order properly to locate said wire, and must also supply a moment to said wire to insure that it exits the ; tip bearing lO0 in a direction parallel to the center line o~
the print head 102. As the aperture in the tip bearing 100 wears, the print wire 104 continues to exert pressure to the left on the upper portion o~ said aperture and to the right on the lower portion of said aperture, as seen in Fig~ 8B, and ~ g _ 34~
thus continues to apply a side load to the bearing. When the wire 104 extends forward to printl and engages the record medium 106, or a platen supporting it, or a ribbon associated therewith, the motion of the print head 102 relative to the record media 106 results in a very heavy side load on the bearing, as shown, in Figs. 8A and 8B. It is this heavy side load, caused by the transverse translation of the print head, that causes excessive tip bearing wear. With a conventional curved wire path, this situa~ion contin~les throughout print head life because the static side load and the moment hold the print wire against the side of the hole in the tip bearing even after considerable wear has occurred, as may readily be seen in Fig. 8B.
The present invention provides a means for routing of print wires that eliminates substantially any static side loading or moments from the tip bearing. Referring to Fig. 1, it will be seen that members or bridges 27 and 29 supply loads such that with an appropriate deflection at an appropriate longitudinal location at member or bridge 28, the wire deflects in such a manner that it becomes coincident with a plane through the center line of the print head slightly to the left of the member 27. If the pattern of apertures 33 of support member 27 (Fig. 6) is the same as that of the apertures in the tip bear-ing 36 (Fig. 7), the result is that no static side loads or moments are imparted to the wires 14 by the tip bearing 36.
When the print head 10 of the present invention is new, a condition of heavy side loading due to the relative motion between the head 10 and the record medium 106, or the platen supporting said record medium, still occurs, and there~
fore wear of the end bearing 36, as shown in Fig. 8C, takes place in a manner similar to that shown in Fig. 8B ~or the conventional orientation of the print wire 104 with respect to the end bearing 100. Eowever, after a period of time, since the perpendicularly oriented print wire 14 is not loaded at the tip bearing, it no longer rests against the side of the hole.
Thus r as the amount of enlargement of the aperture due to wear, designated by distance "d" in Fig. 8D, approaches and equals the transverse translation distance of the print wire 14 caused by its movement with respect to the record medium 106, said distance being designated as "b" in Fig. 8E, the side load due to the relative motion of the print head 10 and the record medium 106 ceases, as shown in Figs. 8D and 8E, and further wear ceases, since the translation distance of the print wire 14 will not increase beyond a predetermined maximum.
While the form of the invention shown and described herein is admirably adapted to fulfill the objects primarily stated, it is to be understood that i~ is not intended to con-fine the invention to the form or embodiment disclosed herein, for it is susceptible of embodiment in various other forms within the scope of the appended claims.
In accordance with one embodiment of the invention, a printing mechanism for printing on record media comprises frame means including an end bearing means having a plurality of printing element receiving apertures disposed therein; a plu-rality of support members mounted on said frame means including a first support member located closest to the end bearing means, spaced therefrom, and having a plurality of printing element receiving apertures disposed therein; a plurality of printing elements extending through said support members and capable of being driven to effect printing, said support members causing said printing elements to be positioned in paths which are sub-stantially in parallel relation to the longitudinal axis of the frame means between said first support member and said end bearing means.
It is accordingly an object of the present invention to provide a print head which includes means for reducing wear of the printer tip bearing.
Another object is to provide a print head having printing element support members configured to constrain the paths of movement of the printing elements adjac~nt to the print tip bearing means to a direction substantially perpendic-ular to the direction of relative movement between the prin-t head and the record media being printed upon, in order to sub-stantially eliminate side loading on said print tip bearing means.~
A further object is to provide a print head which is durable and reliable in operation.
With these and other objects, which will be apparent from the following descriptionr in view, thé invention includes certain noveI features of construction and combinations of parts, one form of embodiment of which is hereinafter described with reference to the drawings which accompany and form a part of this specification.
Brief Description of the Drawings Fig. l is a sectional view of a print head in accor-dance with the present invention;
Fig. 2 is an elevation view, partly broken away, showing the frame and the elongated printing elements of the print head;
Fig. 3 is an enlarged cross sectional view taken along line 3-3 o Fig. 2; and Fig. ~ is an enlarged cross-sectional view taken along line 4-4 of Fig. 2; and Fig. 5 is an enlarged cross-sectional view taken along line 5-5 of Fig. 2; and Fig. 6 is an enlarged cross-sectional view taken along line ~-6 of Fig. 2; and Fig. 7 i5 a bottom view of the frame of Fig. 2, ta~en along line 7-7, showing the tip bearing; and Figs. 8A to 8E inclusive are enlarged partial section-al views showing the printing end o the print head and illustra-ting the manner in which an elongated printing element coacts with the tip bearing under various conditions.
Description of the Preferred Embodiment Reerring now particularly to Fig. l of the drawings, a print head 10 of the wire matrix type is shown. This print ; head is similar in general configuration to the print head dis-closed in United States Patent No. 3,929,214, issued December 30, 1975, to which reference ma~ be had for a more detailed description of certain aspects of the print head 3~:
structure.
A frame 12 is provided to support a plurality of elongated print elements or print wires 14, onl~ two of which are shown, for purposes of simplification and ready understand-ing of the drawings. Each wire 14 has a cap 16 which may be made of plastic or other suitable material, attached to its impact-receiving end to enlarge the area of the impact-receiving surface. Each wire 14 also has a spring 18 disposed at its upper end, which exerts a force upon the cap 1~ to re-siliently bias the wire relative to the frame 12. The spring18 has been omitted from one of the wires of Fig. l, in order that the cap 16 may be more clearly depicted.
The frame 12 includes three side walls 20, 22) 24, a print end member 25 (also shown in Fig. 7) and an upper end member 26 (also shown in Fig. 3). A first print wire support member or bridge 27 (also shown in Fig. 6) is loosely mounted in grooves in the walls 20, 22, 24 close to the print end mem-ber 25, to permit the member 27 to shift laterally with respect to the frame in a plane substantialIy perpendicular to the longitudinal a~is of the frame, and which is parallel to the direction of relative movement between the print head lO and the record media which is to be printed upon by said print head. Two intermediate support members or bridges 28 (also shown in Fig. 5) and 29 (also shown in Fig. 4) are positioned in grooves in the side walls 20, 22 in planes parallel to the plane of the support member 27. The support members 28 and 29 are not intended to move laterally with respect to the rame, and thus fit relatively tightly within their respective grooves.
The members 26, 27, 28, 29 constrain the various 3~L
print wires 14 in predetermined paths, and accomplish the translation of the wires from a generally circular formation at the left end as seen in Fig. 1 to a linear formation at the printing end, and also cause the print wires to move into an essentially planar relationship perpendicular to the direction of relative movement between the record media and the print head, becoming substantially coincident with a plane through the center line of the print head at a point slightly to the left of the member 27, as seen in Fig. 1, and to continue in such planar relationship through the member 27 and the bearing 36 positioned in the pri~t end member 25. The translation is accomplished by passing each wire 14 through a separate hole 30 in the upper end member 26, through similar holes 31, 32, 33 in the members 29, 28, 27 and into a defined position in the bearing 36. The members 27, 28, 29 and the apertures therein are positioned so that the paths of movement of the wires 14 are completely determined thereby. Thus, theoretic-ally, the apertures in the end bearing 36 do not determine the paths of the wires 14 therethrough r and there would be no side loading whatever of the wires thereby. Actually, there may be some slight devlation Erom the ideal plotted paths of the wires 14, and thus some slight side loading.
The bearing 36 is of a material which resists wear and has a low coefficient of friction.
~ pair of mounting flanges 38 and 40 extend laterally from the upper ends of sidewalls 20 and 22. The frame 12 is circular in cross-sectional shape to the left of flanges 38, 40 as seen in Fi~. 1, and terminates in the upper end support member 26 which is of circular configuration. An apertured post 42 e~tends from the member 26 and pro~ides means for assembling the driving means for the wires 14 to the frame 12, as will subsequently be described in greater detail.
As shown in Fig. 1, a plate 44 is provided with a central aperture 46 and is secured to the flanges 38, 40 on the frame 12 by suitable fastening means 48. The circular portion of the frame 12 extends through the aperture 46. A
plurality of holes 50 are provided in the plate 44 for mounting a corresponding plurality, nine in the illustrated embodiment, of actuating means for the wire printing elements 14.
A coil 52, a center pole S4, an "L" shaped outer pole 56 and an armature 58 form the electromagnetic actuating means used in the print head. An armature shim 59 spaces the armatures 58 away from the poles 54 for the purpose of effect-ing faster armature release. A bore 60 is provided in the horizontal leg of the "L" shaped outer pole 56 for receiving the lower extremity of the center pole 54O
A unitary connector 62 is mounted by means of a screw 64 and a washer 66 to the post 42 of the frame 12. The connec-tor 62 has a circular central portion 68 with an annular groove 70 provided in its bottom surface. An 0-ring 72 is inserted in the groove 70 to act as a shock absor~er and to provide a ref-erence surface for the cap 16 of the print wire 14 striking the end of the armature 58. Nine arms 74 are formed integral with the central portion 68 of the connector 62 and extend therefrom.
~ach arm 74 has associated with it a first armature receiving structure 76 and~a second armature receiviny structure 78~ One end of each armature 58 is received and held in place by the structure 76 and the other end of each armature i6 received and guided by the structure 7~. With the connector 62 installed in the position shown, the arras 74 apply forces to the cantilevered distal ends of the armatures, causing their print wire irnpacting ends to rotate about the fulcrum formed by the top edge of the pole 56 and upwardly into ~ngagement with the 0-ring 72. The caps 16 associated with the prin-t wires 14 are maintained in contact with the ends of the armature 58 by means of the forces applied by the springs 18.
As discussed in greater detail in the previously-cited United States Patent No. 3,929,214, the unitary connec-tor 62 serves a number of functions in the assembly and opera-tion of the print head 10, including retaining the armatures 58 in proper relationship to the remainder of the structure, acting as a biasing means for the armatures, providing means for adjusting the air gap between the armatures 58 and the corresponding center poles 52~ forming a reference surface for the armatures 58 and print wire caps 16, to assure that all actuated print wires 14 impact the record medium at substantially the same time during a printing cycle, and, by means of 0-ring 72, absorbing energy from the armatures ~8 and the print wires 14 on return motion after actuation.
As is also described in gxeater detail in the previ-ously-mentioned United States Patent No. 3,929~214, characters such as numbers, letters or symbols are generated by the print head by a sequence of print cycles. Selective actuation of predetermined combinations of print wires 14 through energiza-tion of their corresponding coils 52 during each cycle results in the formation of the desired character on the record medium, with the print head being shifted one position with respect to the record medium after each cycle to be properly located for the next printing cycle.
When a coil 52 is energized, a magnetic flux is created ~hich causes armature 58 to be drawn into contact with ; - 8 -~6~
center pole 59. The movement of armature 58 transmits ener~y into print wire 14, causing i~ to move in an axial direction in the ~rame 12. The force imparted into the wire 14 causes it to move against the spring 18 and its inertia causes it to contin-ue to move downwardly out of contact with the armature 58 after said armature bottoms out against the center pole 54. The impact-delivering end of the print wire 14 extends beyond bear-ing 36 and strikes the record medium, causing a dot to be im-printed. The energy stored in the moving print wire 14 is partially absorbed by the impacted record medium and is par~
tially returned to the print wire 14, aiding the spring 18 in returning the print wire 14 to its rest position.
At approximately the same time that the print wire 14 is impacting the record medium, the coil 52 is deenergized~
The movement exerted on the armature 58 by the arm 74 causes it to rotate away from the center pole 5~ and to return into contact with the 0-ring 72.
Examination of the curved path of movement of a typi-cal print wire above the tip bearing in a conventional matrix print head, such as that disclosed in the previously-cited United States Patent No. 3,929,214, discloses that the tip bearing, such as a bearing 100 of a print head 102, shown in a new, unused condition in Fig. 8A must supply a side load to the print wire 104 in order properly to locate said wire, and must also supply a moment to said wire to insure that it exits the ; tip bearing lO0 in a direction parallel to the center line o~
the print head 102. As the aperture in the tip bearing 100 wears, the print wire 104 continues to exert pressure to the left on the upper portion o~ said aperture and to the right on the lower portion of said aperture, as seen in Fig~ 8B, and ~ g _ 34~
thus continues to apply a side load to the bearing. When the wire 104 extends forward to printl and engages the record medium 106, or a platen supporting it, or a ribbon associated therewith, the motion of the print head 102 relative to the record media 106 results in a very heavy side load on the bearing, as shown, in Figs. 8A and 8B. It is this heavy side load, caused by the transverse translation of the print head, that causes excessive tip bearing wear. With a conventional curved wire path, this situa~ion contin~les throughout print head life because the static side load and the moment hold the print wire against the side of the hole in the tip bearing even after considerable wear has occurred, as may readily be seen in Fig. 8B.
The present invention provides a means for routing of print wires that eliminates substantially any static side loading or moments from the tip bearing. Referring to Fig. 1, it will be seen that members or bridges 27 and 29 supply loads such that with an appropriate deflection at an appropriate longitudinal location at member or bridge 28, the wire deflects in such a manner that it becomes coincident with a plane through the center line of the print head slightly to the left of the member 27. If the pattern of apertures 33 of support member 27 (Fig. 6) is the same as that of the apertures in the tip bear-ing 36 (Fig. 7), the result is that no static side loads or moments are imparted to the wires 14 by the tip bearing 36.
When the print head 10 of the present invention is new, a condition of heavy side loading due to the relative motion between the head 10 and the record medium 106, or the platen supporting said record medium, still occurs, and there~
fore wear of the end bearing 36, as shown in Fig. 8C, takes place in a manner similar to that shown in Fig. 8B ~or the conventional orientation of the print wire 104 with respect to the end bearing 100. Eowever, after a period of time, since the perpendicularly oriented print wire 14 is not loaded at the tip bearing, it no longer rests against the side of the hole.
Thus r as the amount of enlargement of the aperture due to wear, designated by distance "d" in Fig. 8D, approaches and equals the transverse translation distance of the print wire 14 caused by its movement with respect to the record medium 106, said distance being designated as "b" in Fig. 8E, the side load due to the relative motion of the print head 10 and the record medium 106 ceases, as shown in Figs. 8D and 8E, and further wear ceases, since the translation distance of the print wire 14 will not increase beyond a predetermined maximum.
While the form of the invention shown and described herein is admirably adapted to fulfill the objects primarily stated, it is to be understood that i~ is not intended to con-fine the invention to the form or embodiment disclosed herein, for it is susceptible of embodiment in various other forms within the scope of the appended claims.
Claims (15)
1. A printing mechanism for printing on record media comprising frame means including an end bearing means having a plurality of printing element receiving apertures disposed therein:
a plurality of support members operatively supported by said frame means, including a first support member located closest to the end bearing means, spaced therefrom, and having a plurality of printing element receiving apertures disposed therein; and a plurality of printing elements extending through said support members and capable of being driven to effect printing, said support members causing said printing elements to be positioned in paths which are substantially in parallel relation to the longitudinal axis of the frame means between said first support member and said end bearing means.
a plurality of support members operatively supported by said frame means, including a first support member located closest to the end bearing means, spaced therefrom, and having a plurality of printing element receiving apertures disposed therein; and a plurality of printing elements extending through said support members and capable of being driven to effect printing, said support members causing said printing elements to be positioned in paths which are substantially in parallel relation to the longitudinal axis of the frame means between said first support member and said end bearing means.
2. The printing mechanism of claim 1 in which the printing element receiving apertures are disposed in the support members in configurations which constrain the paths of movement of the printing elements to be aligned with each other in planar relationship between said first support member and said end bearing means.
3. The printing mechanism of claim 1 in which said first support member has a degree of freedom of movement in a plane perpendicular to the longitudinal axis of the frame means.
4. The printing mechanism of claim 1 in which said first support member is loosely mounted on said frame means.
5. The printing mechanism of claim 1 in which the pattern of printing element receiving apertures in said first support member is identical to the pattern of printing element receiving apertures in said end bearing means.
6. A printing mechanism for printing on record media comprising:
frame means including an end bearing means having a plurality of linearly aligned printing element receiving apertures disposed therein;
a plurality of support members operatively supported by said frame means including a first support member located closest to the end bearing means and having a plurality of linearly aligned printing element receiving apertures disposed therein;
a plurality of elongated printing elements extending through said support members and capable of being driven in an axial direction to effect printing, said support members constraining the path of movement of said printing elements between said first support member and said end bearing means to a direction substantially perpendicular to the direction of relative movement between the printing mechanism and the record media being printed upon; and driving means operatively connected to said printing elements for driving said printing elements.
frame means including an end bearing means having a plurality of linearly aligned printing element receiving apertures disposed therein;
a plurality of support members operatively supported by said frame means including a first support member located closest to the end bearing means and having a plurality of linearly aligned printing element receiving apertures disposed therein;
a plurality of elongated printing elements extending through said support members and capable of being driven in an axial direction to effect printing, said support members constraining the path of movement of said printing elements between said first support member and said end bearing means to a direction substantially perpendicular to the direction of relative movement between the printing mechanism and the record media being printed upon; and driving means operatively connected to said printing elements for driving said printing elements.
7. The printing mechanism of claim 6 in which said first support member has a degree of freedom of movement in a plane parallel to the direction of relative movement between the printing mechanism and the record media.
8. The printing mechanism of claim 6 in which said first support member is loosely mounted on said frame means.
9. The printing mechanism of claim 6 in which the pattern of printing element receiving apertures in said first support member is identical to the pattern of printing element receiving apertures in said end bearing means.
10. A printing mechanism for printing on record media comprising:
elongated frame means including a front end bearing means having a plurality of linearly aligned printing element receiving apertures disposed therein and a rear support means having a plurality of printing element receiving apertures disposed therein in a non-linear configuration;
a plurality of elongated printing elements extending through said frame means and the front end bearing means and rear support means thereof;
driving means arranged in a non-linear configura-tion with respect to each other, located adjacent said rear support means, for driving said printing elements in an axial direction to effect printing;
a first support member having a plurality of linearly aligned printing element receiving apertures disposed
10. A printing mechanism for printing on record media comprising:
elongated frame means including a front end bearing means having a plurality of linearly aligned printing element receiving apertures disposed therein and a rear support means having a plurality of printing element receiving apertures disposed therein in a non-linear configuration;
a plurality of elongated printing elements extending through said frame means and the front end bearing means and rear support means thereof;
driving means arranged in a non-linear configura-tion with respect to each other, located adjacent said rear support means, for driving said printing elements in an axial direction to effect printing;
a first support member having a plurality of linearly aligned printing element receiving apertures disposed
10. (concluded) therein, and mounted in said frame means; and a plurality of additional support members mounted in said frame means, each having a plurality of printing element receiving apertures disposed therein, said apertures being located in said support member to cause the elongated printing elements to be positioned in paths which are in substantially parallel relation to each other between said first support member and said front end bearing means to minimize side loads on said front end bearing means.
11. The printing mechanism of claim 10 in which said first support member has limited freedom of movement in a plane parallel to the direction of relative movement between printing mechanism and the record media to facilitate the alignment of the elongated printing elements.
12. The printing mechanism of claim 10 in which said first support member is loosely mounted on said frame means to facilitate the alignment of the elongated printing elements.
13. The printing mechanism of claim 10 in which the pattern of printing element receiving apertures in said first support member is identical to the pattern of printing element receiving apertures in said end bearing means.
14. The printing mechanism of claim 10 in which the additional support members are two in number and in which the apertures of these two support members cooperate
14. The printing mechanism of claim 10 in which the additional support members are two in number and in which the apertures of these two support members cooperate
14. (concluded) with the apertures of the first support member to determine the paths of movement of the printing elements so that said printing elements extend through the apertures of the front end bearing means without substantial side loading.
15. A printing mechanism for printing on record media comprising frame means including an end bearing means having a plurality of printing element receiving apertures disposed therein:
a plurality of support members operatively supported by said frame means, including a first support member located closest to the end bearing means, spaced therefrom, and having a plurality of printing element receiving apertures disposed therein; and a plurality of printing elements extending through said support members and capable of being driven to effect printing, said support members causing said printing elements to be positioned in paths which are substantially in parallel relation to each other between said first support member and said end bearing means.
a plurality of support members operatively supported by said frame means, including a first support member located closest to the end bearing means, spaced therefrom, and having a plurality of printing element receiving apertures disposed therein; and a plurality of printing elements extending through said support members and capable of being driven to effect printing, said support members causing said printing elements to be positioned in paths which are substantially in parallel relation to each other between said first support member and said end bearing means.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US80622777A | 1977-06-13 | 1977-06-13 | |
| US806,227 | 1977-06-13 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1096234A true CA1096234A (en) | 1981-02-24 |
Family
ID=25193600
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA303,260A Expired CA1096234A (en) | 1977-06-13 | 1978-05-12 | Wear minimizing means for printing mechanism |
Country Status (5)
| Country | Link |
|---|---|
| JP (1) | JPS546622A (en) |
| CA (1) | CA1096234A (en) |
| DE (1) | DE2825527C2 (en) |
| FR (1) | FR2394401B1 (en) |
| GB (1) | GB1582690A (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| IT1099489B (en) * | 1978-09-11 | 1985-09-18 | Honeywell Inf Systems | PERFECTED MATRIX PRINTER HEAD |
| IT1128976B (en) * | 1980-08-21 | 1986-06-04 | Olivetti & Co Spa | BALLISTIC WIRE PRINT HEAD |
| FR2508848B1 (en) * | 1981-07-03 | 1987-04-03 | Cerem Inf | IMPROVEMENTS ON PRINTER NEEDLE HEADS |
| JPS60187563A (en) * | 1984-03-07 | 1985-09-25 | Tokyo Electric Co Ltd | Dot printer head |
| JPS60255452A (en) * | 1984-05-31 | 1985-12-17 | Copal Co Ltd | Recording head |
| DE225782T1 (en) * | 1985-12-05 | 1988-02-25 | Ncr Corp., Dayton, Ohio | WIRE POINT PRINT HEAD. |
| SG44608A1 (en) * | 1992-07-21 | 1997-12-19 | Seiko Epson Corp | Impact dot printing head and impact dot printer |
Family Cites Families (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2147144A1 (en) * | 1970-09-21 | 1972-03-23 | Teletype Corp | Single-color device for a writing device |
| DE2119641C3 (en) * | 1971-04-22 | 1975-05-15 | Anker-Werke Ag, 4800 Bielefeld | Print head for dot matrix printers |
| US3900094A (en) * | 1973-05-10 | 1975-08-19 | Lrc Inc | Matrix printer with overlapping print dots |
| FR2228619B3 (en) * | 1973-05-10 | 1977-03-11 | Lrc Inc | |
| US3897865A (en) * | 1973-12-11 | 1975-08-05 | Ibm | Dot printing apparatus |
| DE2449235A1 (en) * | 1973-12-11 | 1975-06-12 | Gen Electric | PRINT DEVICE WITH WIRE MATRIX PRINTER HEAD |
| DE2436970A1 (en) * | 1974-07-31 | 1976-02-19 | Siemens Ag | DEVICE IN MOSAIC NEEDLE PRINT HEADS FOR GUIDING PRINTER NEEDLES |
| US3893220A (en) * | 1974-08-01 | 1975-07-08 | Gen Electric | Method of making wire matrix print head nozzle |
| DE2527186C3 (en) * | 1975-06-18 | 1980-10-09 | Philips Patentverwaltung Gmbh, 2000 Hamburg | Mosaic printer with a cylindrical housing |
| CA1125661A (en) * | 1977-04-28 | 1982-06-15 | Noel F. Depew | Vibration dampening printing element guide means |
-
1978
- 1978-05-12 CA CA303,260A patent/CA1096234A/en not_active Expired
- 1978-05-25 GB GB2253078A patent/GB1582690A/en not_active Expired
- 1978-06-05 JP JP6684178A patent/JPS546622A/en active Pending
- 1978-06-09 FR FR7817263A patent/FR2394401B1/en not_active Expired
- 1978-06-10 DE DE19782825527 patent/DE2825527C2/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| DE2825527A1 (en) | 1978-12-14 |
| FR2394401B1 (en) | 1985-06-28 |
| FR2394401A1 (en) | 1979-01-12 |
| DE2825527C2 (en) | 1982-06-09 |
| GB1582690A (en) | 1981-01-14 |
| JPS546622A (en) | 1979-01-18 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |