Claims
- 1. An armature support device of a print head, said support device pivotally supporting an armature at one end thereof, a print wire held at another end thereof, said armature having a base portion adjacent said one end; said support device comprising
- a support member having a pair of arms;
- a circular through hole formed in each arm of said pair of arms, said through holes positioned to have the same axis;
- a penetrating hole formed in said base portion of said armature and having an axis coinciding with said axis of said through holes when said base portion is disposed between said pair of arms; and
- a circular cylindrical torsion spring member comprising a pair of end portions, a center portion and a pair of connecting portions for interconnecting said end portions to said center portion, with said end portions being disposed in said through holes and said center portion being disposed in said penetrating hole,
- wherein said end portions have predetermined diameters, said center portion has a selected diameter, and said connection portions have diameters smaller than said predetermined diameters and smaller than said selected diameter,
- wherein said spring member is connected with said support member and said armature at said end portions and at said center portion,
- wherein said end portions are brazed to said pair of arms and said center portion is brazed to said base portion,
- wherein said spring member normally retains said armature at a predetermined position, and when said armature is pivoted away from said predetermined position, said center portion is pivoted together with said armature, whereby said connecting portions are twisted to produce a torsional force acting to restore said armature to said predetermined position, and
- wherein said armature further comprises a second hole having an axis approximately perpendicular to the axis of said penetrating hole and leading to said penetrating hole from a surface of said armature, and
- wherein each arm of said pair of arms further comprises a third hole having an axis approximately perpendicular to said axis of said circular through hole and leading to said circular through hole from a surface of said each arm positioned on the on the same side as said surface of said armature, said second and third holes are initially filled with a brazing material, said brazing material forming said brazing between said armature and said center portion of said spring, and between said pair of arms and said pair of end portions of said spring.
- 2. The device of claim 1, wherein said brazing material is silver solder.
- 3. The device of claim 2, wherein said armature is made of permendur alloy of cobalt and iron.
- 4. The device of claim 2, wherein said spring member is made of mar-aging steel.
- 5. The device of claim 1, wherein said armature is provided with an opening so as to reduce the mass of said armature.
- 6. A print head, including
- a support member disposed between a front yoke and a rear frame;
- a plurality of armatures, each having a base portion at one thereof;
- said rear frame having a plurality of solenoids disposed so as to face each of said plurality of armatures;
- a permanent magnet disposed on said rear frame;
- a print wire secured to another end of each of said armatures; and
- a spring member pivotally connecting said one end of each armature to said support member;
- wherein said print head further comprises
- said support member having a plurality of pairs of arms;
- a circular through hole formed in each arm of said pair of arms, each said through holes in each of said pair of arms being positioned to have the same axis;
- a penetrating hole formed in said base portion of each armature, and having an axis coinciding with said axis of said through holes when said base portion is disposed between said pair of arms,
- each spring member comprising a pair of end portions, a center portion, and a pair of connecting portions connecting said end portions to said center portion, said end portions being disposed within said through holes and said center portion being disposed within said penetrating hole, wherein said end portions have a predetermined diameter, said center portion has a selected diameter and said connection portions have a diameter smaller than said predetermined diameter and smaller than said selected diameter, and wherein each said spring member is connected to each said support member and each said armature at said end portions and at said center portion,
- wherein said end portions are brazed to said arms and said center portion is brazed to said base portion,
- wherein each said armature is normally retained at a predetermined position by magnetic force of said permanent magnet with said center portion of each said spring member being twisted to cause torsion strain, each said armature being pivoted from said predetermined position to an operating position by a torsional force produced by said torsion strains when said solenoid is energized to thereby neutralize the magnetic force caused by said permanent magnet,
- wherein said armature is provided with a second hole having having an axis perpendicular to said axis of said penetrating hole and leading to said penetrating hole from a surface of said armature, and wherein each arm of said pair of arms is provided with a third hole having an axis perpendicular to said axis of said circular through hole and leading to said circular through hole from a surface of said each arm positioned on the same side as said surface of said armature,
- said second and third holes initially filled with a brazing material forming the brazing between said armature and said center portion of said spring, and between said pair of arms and said pair of end portions of said spring.
- 7. The print head of claim 6, wherein each said armature is made of permendur alloy of cobalt and iron, and each said spring member is made of mar-aging steel.
- 8. The print head of claim 6, wherein said front yoke has a plurality of projections projected between adjacent said armatures, and said armature is provided with an hole, and said hole has an axis perpendicular to said axis of said penetrating hole and is formed in a surface of said armature opposed with the other surface thereof opposite to said solenoid, so as to form a part of the magnetic circuit, which enters from projections of said front yoke to the lateral surface of said armature and reaches to said solenoid without crossing the hole.
Priority Claims (2)
Number |
Date |
Country |
Kind |
58-93787 |
Jun 1983 |
JPX |
|
58-93788 |
Jun 1983 |
JPX |
|
Parent Case Info
This application is a continuation of Ser. No. 815,680 filed Jan. 6, 1986, now abandoned, which was a continuation of Ser. No. 615,160 filed May 30, 1984, also abandoned.
US Referenced Citations (10)
Foreign Referenced Citations (4)
Number |
Date |
Country |
65620 |
Dec 1982 |
EPX |
56-175 |
Jan 1981 |
JPX |
57-203567 |
Dec 1982 |
JPX |
58-8665 |
Jan 1983 |
JPX |
Continuations (2)
|
Number |
Date |
Country |
Parent |
815680 |
Jan 1986 |
|
Parent |
615160 |
May 1984 |
|