Claims
- 1. A piezoelectric printing head comprising:
- a base frame;
- a plurality of piezoelectric actuator assemblies mounted on said base frame, each actuator assembly comprising:
- a piezoelectric element having one end rigidly secured to said base frame and another free end;
- an armature having a base end portion and a tip end to which a printing wire is rigidly connected;
- a magnifying mechanism including a support spring for connecting said base frame to said base end portion of said armature at a first position and a movable spring, arranged substantially in parallel to said support spring, for connecting said free end of said piezoelectric element to said base end portion of said armature at a second position adjacent to said first position, so that, when said piezoelectric element is electrically energized, a displacement of said piezoelectric element is magnified to be transmitted to said printing wire; and
- a vibration damping buffer member disposed between a vertical portion of said base frame and said base end portion of said armature, wherein the space between said support spring and said movable spring is free of said buffer member, and said buffer member is a gel.
- 2. The piezoelectric printing head as set forth in claim 1, wherein:
- said base frame is substantially annular and has a substantially L-shaped cross-section comprising a horizontal bottom portion projecting inward and a side vertical portion extending upward from said horizontal bottom portion; and
- said piezoelectric element is rigidly secured to an upper surface of the horizontal bottom portion of the base frame, and said support spring is rigidly connected to an inner surface of said side vertical portion of said base frame.
- 3. The piezoelectric printing head as set forth in claim 2, wherein said support spring is rigidly connected to an upper position of said inner surface of said side vertical portion adjacent to said free end of the piezoelectric element, and said buffer member covers said support spring and said movable spring.
- 4. The piezoelectric printing head as set forth in claim 2, wherein said side vertical portion of the base frame has an upper surface, and said buffer member is disposed between said upper surface of said side vertical portion and said base end of said armature.
- 5. The piezoelectric printing head as set forth in claim 4, wherein said base frame further comprises an upper projection projecting upward from said upper surface of said side vertical portion, and said buffer member is disposed between said upper projection and said base end portion of said armature.
- 6. The piezoelectric printing head as set forth in claim 5, wherein said upper projection has a horizontal extension extending from an upper end of said upper projection so as to cover said base end portion said armature, and said buffer member is filled in a region defined by said upper projection, said extension and said base end portion of the armature.
- 7. The piezoelectric printing head as set forth in claim 4, further comprising a block, wherein said movable spring is connected to said free end of the piezoelectric element by means of said block, and said buffer member is also disposed between said block and said base end portion of said armature.
- 8. The piezoelectric printing head as set forth in claim 7, wherein said block has a substantially horizontal upper surface which is substantially at the same horizontal level as said upper surface of the vertical portion, and said buffer member is disposed between said upper surface of the block and said base end portion of said armature.
- 9. The piezoelectric printing head as set forth in claim 7, wherein said block has an upper surface provided with a recess, at least a part of said base end portion of said armature is accommodated in said recess, and said buffer member is disposed in said recess, preventing removal of said buffer member from said recess.
- 10. The piezoelectric printing head as set forth in claim 1, wherein said buffer member is a silicon gel.
- 11. A piezoelectric printing head comprising:
- a base frame;
- a plurality of piezoelectric actuator assemblies mounted on said base frame, each actuator assembly comprising:
- a piezoelectric element having one end rigidly secured to said base frame and another free end;
- an armature having a base end portion and a tip end to which a printing wire is rigidly connected;
- a magnifying mechanism comprising at least means for connecting said free end of the piezoelectric element to said base end portion of the armature, so that, when said piezoelectric element is electrically energized, a displacement of said piezoelectric element is magnified to be transmitted to said printing wire; and
- a vibration damping buffer member disposed between a vertical portion of said base frame and said base end portion of said armature, wherein the space between said support spring and said movable spring is free of said buffer member, and said buffer member is a gel.
- 12. A piezoelectric printing head comprising:
- a base frame;
- a plurality of piezoelectric actuator assemblies mounted on said base frame, each actuator assembly comprising:
- a piezoelectric element having one end connected to said base frame and another free end;
- an armature having a base end portion and a tip end to which a printing wire is rigid connected;
- a magnifying mechanism comprising at least means for connecting said free end of the piezoelectric element to said base end portion of the armature, so that, when said piezoelectric element is electrically energized, a displacement of said piezoelectric element is magnified to be transmitted to said printing wire;
- said one end of the piezoelectric element having a block which is connected to said base frame by means of a connecting member comprising an adjustable screw so as to give a prestress to said piezoelectric element;
- an adhesive agent for adhering said connecting member to said block of the piezoelectric element; and
- wherein one of said block and said connecting member has a cut-out portion and the other has a protruding portion which is engaged with said cut-out portion, and said adhesive agent is filled in a gap between said protruding portion and said cut-out portion.
- 13. A piezoelectric printing head comprising:
- a base frame;
- a plurality of piezoelectric actuator assemblies mounted on said base frame, each actuator assembly comprising:
- a piezoelectric element having one end connected to said base frame and another free end;
- an armature having a base end portion and a tip end to which a printing wire is rigidly connected;
- a magnifying mechanism comprising at least means for connecting said free end of the piezoelectric element to said base end portion of the armature, so that, when said piezoelectric element is electrically energized, a displacement of said piezoelectric element is magnified to be transmitted to said printing wire;
- said one end of the piezoelectric element having a block which is connected to said base frame by means of a connecting member comprising an adjustable screw so as to give a prestress to said piezoelectric element;
- an adhesive agent for adhering said connecting member to said block of the piezoelectric element; and
- a releasing member provided on said base frame over at least a region opposite to said block, in such a manner that an attachment of the adhesive agent to said base frame is prevented.
- 14. The piezoelectric printing head as set forth in claim 13, wherein said releasing member is one of a film and a sheet and made of one of polytetrafluoroethylene and silicon.
- 15. A piezoelectric printing head comprising:
- a base frame;
- a plurality of piezoelectric actuator assemblies mounted on said base frame, each actuator assembly comprising:
- a piezoelectric element having one end connected to said base frame and another free end;
- an armature;
- a beam having a base end rigidly connected to said armature and a tip end to which a printing wire is rigidly connected;
- a magnifying mechanism comprising at least means for connecting said free end of the piezoelectric element to said armature, so that, when said piezoelectric element is electrically energized, a displacement of said piezoelectric element is magnified to be transmitted to said printing wire;
- said armature and said beam having respective connecting portions connected to each other, said connecting portion of said armature having a groove extending in a moving direction of said beam and said connecting portion of said beam being inserted into and rigidly engaged with said groove;
- a width of said connecting portion of said beam in the moving direction is larger than a width of said connecting portion of the armature in the moving direction, wherein both ends of the connecting portion of said beam protrude upward and downward, respectively, from the connecting portion of said armature.
- 16. The piezoelectric printing head as set forth in claim 15, wherein said beam is plate-like, wherein both ends of said connecting portion of said plate-like beam protrude upward and downward, respectively, from said connecting portion of the armature.
- 17. The piezoelectric printing head as set forth in claim 15, wherein, said armature has a rotation center about which said armature turns, so that a displacement of said piezoelectric element is magnified to be transmitted to said printing wire when said piezoelectric element is electrically energized, said beam has a center of gravity, and said respective connection portions of said armature and beam including said groove of said armature extend perpendicular to a straight line passing through said rotation center and said center of gravity.
- 18. A piezoelectric printing head comprising:
- a base frame; and
- a plurality of piezoelectric actuator assemblies mounted on said base frame, each actuator assembly comprising:
- a printing wire,
- a piezoelectric element having a first end rigidly secured to said base frame and a second end which is free,
- an armature having a base end portion, and a tip end portion rigidly connected to said printing wire,
- a magnifying mechanism including a support spring connecting said base frame to said base end portion of said armature at a first position of said base end portion, and a movable spring, arranged substantially in parallel to said support spring and creating a gap with said first support spring, for connecting said second end of said piezoelectric element to said base end portion of said armature at a second position adjacent to said first position, wherein said magnifying mechanism magnifies a displacement of said piezoelectric element and transmits the magnified displacement to said printing wire, and
- vibration damping means disposed between said base end portion of said armature and said base frame, wherein said gap is free of said vibration damping means.
- 19. The piezoelectric printing head as claimed in claim 18, wherein said vibration damping means contacts said base end portion of said armature, said base frame and said support spring, and is at a first side of said support spring opposite a second side of said support spring which faces said movable spring.
- 20. The piezoelectric printing head as claimed in claim 19, further comprising:
- a block connecting said movable spring with said second end of said piezoelectric element; and
- said vibration damping means also disposed between said based end portion of said armature and said block, and in contact with said base end portion of said armature, said block and said movable spring at a first side of said movable spring opposite a second side of said movable spring facing said support spring.
- 21. The piezoelectric printing head as claimed in claim 19, wherein:
- said base frame is substantially annular and has a substantially L-shaped cross-section comprising a bottom portion having a surface and extending in a first direction toward said one of said plurality of piezoelectric elements and a side portion extending perpendicular to said bottom portion and substantially parallel to said one piezoelectric element; and
- said one piezoelectric element is rigidly secured to said surface of said bottom portion, and said support spring is rigidly connected to said side portion.
- 22. The piezoelectric printing head as claimed in claim 18, wherein said armature further comprises:
- a first portion connected to said base end portion and having a rotation center about which said first portion turns and a connection end; and
- a beam having a base end rigidly connected to said connection end of said first portion and having a center of gravity, said base end and said connecting end extending perpendicularly to a straight line passing through said rotation center and said center of gravity.
Priority Claims (3)
Number |
Date |
Country |
Kind |
4-116064 |
May 1992 |
JPX |
|
4-116065 |
May 1992 |
JPX |
|
4-164470 |
Jun 1992 |
JPX |
|
Parent Case Info
This application is a continuation, of application Ser. No. 08/057,825, filed May 7, 1993, now abandoned.
US Referenced Citations (8)
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Non-Patent Literature Citations (1)
Entry |
Patent Abstracts of Japan vol. 8, No. 191 (M-322) (1628) 4 Sep. 1984 & JP-A-59 081 181 (Nippon Denki K.K.) 10 May 1984 *abstract*. |
Continuations (1)
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Number |
Date |
Country |
Parent |
57825 |
May 1993 |
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