US3780648A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High speed print hammer with dynamic damper means
Assignee: NORTEC COMPUTER DEVICES
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Filing: 1969-09-02
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Granted: 1973-12-25
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Expires: 1989-09-02
Abstract
Abstract A hammer for impact printers having a hammer arm with a striking face mounted for movement toward and away from type to cause a document located between the hammer face and type to be printed when the hammer arm is propelled toward the type. The hammer arm is supported by two spring reeds and is cocked away from the printing position against a permanent magnet. Printing is effected by opposing the permanent magnetic field with an electromagnetic field to release the cocked hammer arm. The spring reeds cause the hammer to be propelled toward the type. A dynamic damper supported by another spring reed is cocked with the hammer arm. The natural frequency of the damper is lower than that of the hammer arm, causing the damper to strike the rebounding hammer arm after printing. The energy in the rebounding hammer arm is absorbed by the impact of the damper to reduce oscillations in the hammer arm.
Inventors
- 👤 R Curtiss
- 👤 R Holzman
- 👤 S Lazarow
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 06:57
CPC Classifications
B; B41; B41J; B41J9/00; B41J9/42
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
267 words
In a printer, the combination comprising a hammer assembly having a cocked position, a rest position and an impact position, said hammer assembly including a support, a hammer arm having an impact face and a damping lip on opposing portions of said hammer arm, a damping mass having an impact face, first spring means having a first natural frequency coupling said arm to said support, second spring means having a second natural frequency less than said first natural frequency, and coupling said damping mass to said support, said second spring means supporting said damping mass impact face adjacent said damping lip, means for moving said hammer arm from said rest position to said cocked position and tensing said first spring means, said hammer arm damping lip moving said damping mass from said rest position to said cocked position and tensing said second spring means, means for releasing said hammer arm and damping mass for movement in accordance with the energy stored in said first and second spring means from said cocked position to said impact position, said hammer arm moving at a first rate determined by the natural frequency of said first spring means, and said damping mass moving at a second rate lower than said first rate and determined by the natural frequency of said second spring means, impacted means, said hammer arm impact face imparting said impacted means in said impact position and rebounding therefrom, said damping mass impact face and said hammer arm damping lip colliding at said rest position, thereby substantially damping the movement of both said damping mass and said hammer arm.
Claim 2
Dependent Claim
267 words
In a printer, the combination comprising a hammer assembly having a cocked position, a rest position and an impact position, said hammer assembly including a support, a hammer arm having an impact face and a damping lip on opposing portions of said hammer arm, a damping mass having an impact face, first spring means having a first natural frequency coupling said arm to said support, second spring means having a second natural frequency less than said first natural frequency, and coupling said damping mass to said support, said second spring means supporting said damping mass impact face adjacent said damping lip, means for moving said hammer arm from said rest position to said cocked position and tensing said first spring means, said hammer arm damping lip moving said damping mass from said rest position to said cocked position and tensing said second spring means, means for releasing said hammer arm and damping mass for movement in accordance with the energy stored in said first and second spring means from said cocked position to said impact position, said hammer arm moving at a first rate determined by the natural frequency of said first spring means, and said damping mass moving at a second rate lower than said first rate and determined by the natural frequency of said second spring means, impacted means, said hammer arm impact face imparting said impacted means in said impact position and rebounding therefrom, said damping mass impact face and said hammer arm damping lip colliding at said rest position, thereby substantially damping the movement of both said damping mass and said hammer arm.
Claim 3
Dependent Claim
26 words
The printer described in claim 1, wherein said first spring means comprises two flexible reeds substantially perpendicular to the direction of movement of said hammer arm.
Claim 4
Dependent Claim
24 words
The printer described in claim 2, wherein said second spring means is a flexible reed that is substantially parallel to said two flexible reeds.
Claim 5
Dependent Claim
21 words
The printer described in claim 2, wherein said springs are flexible reeds that bias said hammer arm to its rest position.
Claim 6
Dependent Claim
70 words
The printer described in claim 1, wherein the hammer arm is biased toward its rest position, cocking means wherein said hammer arm is initially cocked away from its rest position, means for supplying a steady magnetic force to maintain said hammer arm in its cocked position, and means for opposing the steady magnetic force with a momentary magnetic force to release said hammer arm from its cocked position toward impact.
Claim 7
Dependent Claim
29 words
The printer described in claim 5, wherein said cocking means comprises a continuously reciprocating bail and a cocking arm which is controllably clutched to the bail by magnetic means.
Claim 8
Dependent Claim
44 words
The printer described in claim 1, wherein said hammer assembly is adjustable in the direction of movement of said hammer arm to control the rest position of said hammer arm, whereby the flight time, speed and impact force of the hammer arm are controllable.
Claim 9
Dependent Claim
41 words
The printer described in claim 1, wherein said impacted means includes type-presenting means, and said type-presenting means moves along a line to be printed and is adapted to print on a document located between said hammer face and said type-presenting means.
Claim 10
Dependent Claim
42 words
The printer described in claim 1, wherein said type-presenting means moves along a line to be printed and is adapted to print on a document located on the side of said type-presenting means opposite to the side impacted by said hammer face.
Claim 11
Dependent Claim
19 words
The printer described in claim 9, wherein the type-presenting means is comb-shaped with flexible extensions that support the type.
Claim 12
Dependent Claim
206 words
For use with a printer, a hammer assembly, said hammer assembly comprising a support, a hammer arm, said hammer arm having an impact face and a damping Lip on opposite surface portions thereof, first spring means mounting said arm to said support, a damping mass, said damping mass including an impact face positioned proximate to said damping lip on said hammer arm, second spring means coupling said damping mass to said support, said second spring having a lower natural frequency than said first spring, said printer including first means for moving said hammer arm and said damping mass to a cocked position relative to said support, thereby storing energy in said first and second spring means, second means for releasing said hammer arm from said cocked position, said hammer and damping mass undergoing a resultant movement caused by release of the energy stored in said first and second spring means, an impacted means, said impacted means positioned so as to be impacted by the impact face of said hammer arm, said hammer arm rebounding after said impact in a direction opposite said forward motion, said damping mass and said damping lip colliding, said collision damping the movement of both said damping mass and said hammer arm.
Claim 13
Dependent Claim
206 words
For use with a printer, a hammer assembly, said hammer assembly comprising a support, a hammer arm, said hammer arm having an impact face and a damping Lip on opposite surface portions thereof, first spring means mounting said arm to said support, a damping mass, said damping mass including an impact face positioned proximate to said damping lip on said hammer arm, second spring means coupling said damping mass to said support, said second spring having a lower natural frequency than said first spring, said printer including first means for moving said hammer arm and said damping mass to a cocked position relative to said support, thereby storing energy in said first and second spring means, second means for releasing said hammer arm from said cocked position, said hammer and damping mass undergoing a resultant movement caused by release of the energy stored in said first and second spring means, an impacted means, said impacted means positioned so as to be impacted by the impact face of said hammer arm, said hammer arm rebounding after said impact in a direction opposite said forward motion, said damping mass and said damping lip colliding, said collision damping the movement of both said damping mass and said hammer arm.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-12-24 | 1977-06-25 | 1977-12-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-24 | 1981-06-25 | 1981-12-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-24 | 1985-06-25 | 1985-12-25 | $7700.00 | Window Closed / Lapsed |