Patent US3834304A successfully refreshed from Google Patents.
US3834304A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Helical bar printer and hammer therefor
Assignee: Potter Instrument Co Inc
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Filing: 1970-05-21
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Granted: 1974-09-10
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Expires: 1990-05-21
Abstract
Abstract In a printer which selectively prints in response to binary coded input character signals, a plurality of rigidly supported, lightweight blades repeatedly strike a continuously rotating helical bar, printing dot patterns. A movable, lightweight coil fixed to each blade respectively and disposed in a magnetic field drives the blade. Logic circuits, which control the hammers to print alphanumeric characters, include a read only memory which stores binary signal sets representing dot patterns to be printed in rows to compose alphanumeric characters. In response to the received binary characters, addresses in the read only memory are selected to compose the corresponding alphanumeric characters. The binary signal sets at the selected addresses are read out to shift registers, one corresponding to each hammer. The signals in the shift register are read serially out of the shift registers and control actuation of the corresponding hammers as they are read out.
Inventors
- 👤 J Potter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 22:55
CPC Classifications
B; B41; B41J; B41J2/00; B41J2/485; B41J2/495
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
224 words
A printer comprising a bar formed in a helix, means to rotate said bar about the axis of said helix, at least one hammer positioned to strike said bar as said bar rotates, said hammer having a striking edge that extends along a print line and spans a convolution of said helix, means mounting said hammer for movement of said striking edge in a predetermined path to strike said bar to print a dot while rigidly restraining said striking edge from twistiNg about any axis perpendicular to the direction of movement of said striking edge in said predetermined path, a coil of electrically conducting wire affixed to said hammer, means for generating a magnetic field which passes through said coil, said coil being supported so that it is free to move relative to said field and to drive said hammer against said bar, said hammer including means urging said hammer away from said helix when said coil is not energized, a portion of said hammer adjacent to said coil being made from a material having a high permeability, said urging means being the force of attraction between the field generated by said permanent magnet and said hammer portion, and means to apply firing pulses to said coil to drive said striking edge against said bar to print a dot for each applied firing pulse.
Claim 2
Dependent Claim
224 words
A printer comprising a bar formed in a helix, means to rotate said bar about the axis of said helix, at least one hammer positioned to strike said bar as said bar rotates, said hammer having a striking edge that extends along a print line and spans a convolution of said helix, means mounting said hammer for movement of said striking edge in a predetermined path to strike said bar to print a dot while rigidly restraining said striking edge from twistiNg about any axis perpendicular to the direction of movement of said striking edge in said predetermined path, a coil of electrically conducting wire affixed to said hammer, means for generating a magnetic field which passes through said coil, said coil being supported so that it is free to move relative to said field and to drive said hammer against said bar, said hammer including means urging said hammer away from said helix when said coil is not energized, a portion of said hammer adjacent to said coil being made from a material having a high permeability, said urging means being the force of attraction between the field generated by said permanent magnet and said hammer portion, and means to apply firing pulses to said coil to drive said striking edge against said bar to print a dot for each applied firing pulse.
Claim 3
Dependent Claim
171 words
A high speed printer comprising a bar formed into a helix, means to rotate said bar about the axis of said helix, at least one hammer comprising a rigid frame, and a blade mounted on said frame, means pivotally mounting said frame on a pivot axis rigidly fixed with respect to and extending generally parallel to the axis of said helix, said blade being spaced from said pivot axis and having an edge extending generally parallel to the axis of said helix and positioned adjacent to said bar so as to be able to strike said bar by pivoting about said pivot axis, a coil of electrically conducting wire fixed to said blade, means for generating a magnetic field passing radially through said coil, said coil being supported so that it is free to move relative to said field and drive said blade against said bar, and means to apply firing pulses to said coil to drive said blade against said bar to print a dot for each applied firing pulse.
Claim 4
Dependent Claim
171 words
A high speed printer comprising a bar formed into a helix, means to rotate said bar about the axis of said helix, at least one hammer comprising a rigid frame, and a blade mounted on said frame, means pivotally mounting said frame on a pivot axis rigidly fixed with respect to and extending generally parallel to the axis of said helix, said blade being spaced from said pivot axis and having an edge extending generally parallel to the axis of said helix and positioned adjacent to said bar so as to be able to strike said bar by pivoting about said pivot axis, a coil of electrically conducting wire fixed to said blade, means for generating a magnetic field passing radially through said coil, said coil being supported so that it is free to move relative to said field and drive said blade against said bar, and means to apply firing pulses to said coil to drive said blade against said bar to print a dot for each applied firing pulse.
Claim 5
Dependent Claim
125 words
A printer comprising a print member, at least one hammer positioned adjacent to said print member and movable to strike said member to carry out printing, an electrically conducting coil fixed to said hammer, means defining a gap and for generating a magnetic field passing through said gap, said coil being positioned in said magnetic field in said gap free from the surfaces defining said gap, a portion of said hammer adjacent to said gap being of a material having a high permeability whereby said magnetic field at said gap urges said hammer away from said print member, and means to apply firing pulses to said coil to drive said hammer against said print member to print a predetermined figure for each applied firing pulse.
Claim 6
Dependent Claim
125 words
A printer comprising a print member, at least one hammer positioned adjacent to said print member and movable to strike said member to carry out printing, an electrically conducting coil fixed to said hammer, means defining a gap and for generating a magnetic field passing through said gap, said coil being positioned in said magnetic field in said gap free from the surfaces defining said gap, a portion of said hammer adjacent to said gap being of a material having a high permeability whereby said magnetic field at said gap urges said hammer away from said print member, and means to apply firing pulses to said coil to drive said hammer against said print member to print a predetermined figure for each applied firing pulse.
Claim 7
Dependent Claim
193 words
A printer comprising a bar formed in a helix, means to rotate said bar about the axis of said helix, at least one hammer positioned to strike said bar as said bar rotates, said hammer comprising a rigid frame rigidly supporting a striking blade having a striking edge that extends along a print line and spans a convolution of said helix, means pivotally mounting said frame about a pivot axis rigidly fixed with respect to the axis of said helix for movement of said striking edge in a predetermined path to strike said bar to print a dot while rigidly restraining said striking edge from twisting about any axis perpendicular to the direction of movement of said striking edge in said predetermined path, a coil of electrically conducting wire affixed to said striking blade, means for generating a magnetic field which passes through said coil, said coil being supported so that it is free to move relative to said field and drive said hammer against said bar, and means to apply firing pulses to said coil to drive said striking edge against said bar to print a dot for each applied firing pulse.
Claim 8
Dependent Claim
193 words
A printer comprising a bar formed in a helix, means to rotate said bar about the axis of said helix, at least one hammer positioned to strike said bar as said bar rotates, said hammer comprising a rigid frame rigidly supporting a striking blade having a striking edge that extends along a print line and spans a convolution of said helix, means pivotally mounting said frame about a pivot axis rigidly fixed with respect to the axis of said helix for movement of said striking edge in a predetermined path to strike said bar to print a dot while rigidly restraining said striking edge from twisting about any axis perpendicular to the direction of movement of said striking edge in said predetermined path, a coil of electrically conducting wire affixed to said striking blade, means for generating a magnetic field which passes through said coil, said coil being supported so that it is free to move relative to said field and drive said hammer against said bar, and means to apply firing pulses to said coil to drive said striking edge against said bar to print a dot for each applied firing pulse.
Claim 9
Dependent Claim
79 words
A printer as recited in claim 4 further comprising means to receive binary coded signals representing alphanumeric characters, and logic means responsive to said binary coded signals to control the application of said firing pulses to said coil to print dots in patterns to compose the alphanumeric characters represented by said binary coded signals in a plurality of character positions along said print line, said hammeR blade extending along said print line through a plurality of said character positions.
Claim 10
Dependent Claim
24 words
A printer as received in claim 4 further including means located adjacent each end of said striking edge to dampen oscillation of the hammer.
Claim 11
Dependent Claim
45 words
A printer as in claim 4 wherein said means for generating a magnetic field comprises a permanent magnet and a core within said coil and a pole piece substantially surrounding said coil in order to concentrate the field produced by said magnet across said coil.
Claim 12
Dependent Claim
25 words
A printer as recited in claim 7 wherein said hammer includes means urging said printer away from said helix when said coil is not energized.
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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) | 1977-09-09 | 1978-03-11 | 1978-09-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-09 | 1982-03-11 | 1982-09-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-09 | 1986-03-11 | 1986-09-10 | $7700.00 | Window Closed / Lapsed |