US3678847A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hammer firing system for a high speed printer
Assignee: Potter Instrument Co Inc
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Filing: 1970-06-25
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Granted: 1972-07-25
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Expires: 1990-06-25
Abstract
Abstract In a high speed printer the hammers are fired by first applying a firing pulse to the hammer and then applying a damping pulse to the hammer as the hammer is rebounding. The damping pulse cancels out the kinetic energy of the hammer and brings it more quickly to rest each time the hammer is fired. The firing circuit comprises a transistor having the hammer coil connected in the collector circuit thereof and a resistance in the emitter circuit thereof. When the hammer is fired the transistor is initially driven into saturation. When the transistor comes out of saturation, negative feedback provided by the resistance in the emitter circuit maintains the firing pulse current constant to the end of the firing pulse.
Inventors
- 👤 Charles B Pear Jr
- 👤 Joseph A Ross
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 19:24
CPC Classifications
B; B41; B41J; B41J9/00; B41J9/26; B41J9/38; B41J2/00; B41J2/485; B41J2/495; B41J9/42
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
113 words
In a high speed printer having a print member and at least one pulse responsive electromagnetically operated hammer, said hammer being fired to strike said print member to thereby print in response to firing pulses applied thereto, the improvement comprising means selectively operable to apply a firing pulse to said hammer to cause said hammer to strike against said print member and rebound therefrom and to apply a second pulse to said hammer following said firing pulse while said hammer is still moving, said second pulse being of a polarity to oppose the kinetic energy of said hammer and being of insufficient impulse content to cause said hammer to strike said print member.
Claim 2
Dependent Claim
113 words
In a high speed printer having a print member and at least one pulse responsive electromagnetically operated hammer, said hammer being fired to strike said print member to thereby print in response to firing pulses applied thereto, the improvement comprising means selectively operable to apply a firing pulse to said hammer to cause said hammer to strike against said print member and rebound therefrom and to apply a second pulse to said hammer following said firing pulse while said hammer is still moving, said second pulse being of a polarity to oppose the kinetic energy of said hammer and being of insufficient impulse content to cause said hammer to strike said print member.
Claim 3
Dependent Claim
26 words
In a high speed printer as recited in claim 1 wherein said second pulse is applied while said hammer is rebounding away from said print member.
Claim 4
Dependent Claim
56 words
In a high speed printer as recited in claim 2 wherein the ratio of the impulse content of said second pulse to that of said firing pulse is approximately equal to the ratio of the velocity of said hammer upon rebounding from said print member to the velocity of said hammer in striking said print member.
Claim 5
Dependent Claim
39 words
In a high speed printer as recited in claim 1 wherein the impulse content of said second pulse is such to approximately cancel out the kinetic energy of said hammer when said second pulse is applied to said hammer.
Claim 6
Dependent Claim
23 words
In a high speed printer as recited in claim 1 wherein said firing pulse is terminated before said hammer strikes said print member.
Claim 7
Dependent Claim
41 words
In a high speed printer as recited in claim 5 wherein said second pulse is not applied to said hammer until said hammer has rebounded from said print member and has cleared the medium on which said printing is carried out.
Claim 8
Dependent Claim
49 words
In a high speed printer as recited in claim 1 wherein said means to apply pulses to said hammer comprises an amplifier connected to apply pulses to said hammer in response to pulses applied to the input thereof and includes means to apply negative feedback signal to said amplifier.
Claim 9
Dependent Claim
53 words
In a high speed printer as recited in claim 7 wherein said amplifier comprises a transistor, wherein said hammer has an actuating coil connected in the collector circuit of said transistor, and wherein a resistance is connected in the emitter circuit of said transistor to apply said negative feedback signal to said amplifier.
Claim 10
Dependent Claim
57 words
In a high speed printer as recited in claim 3 wherein said means to apply pulses to said hammer comprises an amplifier connected to apply pulses to said hammer in response to pulses applied to the input theReof, said amplifier including negative feedback means for maintaining a constant current amplitude of said pulses applied to said hammer.
Claim 11
Dependent Claim
147 words
In a high speed printer comprising a print member and at least one pulse-responsive, electromagnetically-operated hammer, said hammer being fired to strike said print member and carry out printing in response to firing pulses applied thereto, the improvement comprising means selectively operable to apply a firing pulse to said hammer in each of a series of successive firing periods and to apply a damping pulse to said hammer following each firing pulse only if no firing pulse is to be applied to said hammer in the next succeeding firing period, said damping pulse having the same polarity of said firing pulse and being applied to said hammer while said hammer is rebounding from the medium on which the printing is being carried out as a result of the preceding firing pulse, said damping pulse having insufficient impulse content to cause said hammer to restrike said print member.
Claim 12
Dependent Claim
147 words
In a high speed printer comprising a print member and at least one pulse-responsive, electromagnetically-operated hammer, said hammer being fired to strike said print member and carry out printing in response to firing pulses applied thereto, the improvement comprising means selectively operable to apply a firing pulse to said hammer in each of a series of successive firing periods and to apply a damping pulse to said hammer following each firing pulse only if no firing pulse is to be applied to said hammer in the next succeeding firing period, said damping pulse having the same polarity of said firing pulse and being applied to said hammer while said hammer is rebounding from the medium on which the printing is being carried out as a result of the preceding firing pulse, said damping pulse having insufficient impulse content to cause said hammer to restrike said print member.
Claim 13
Dependent Claim
103 words
A combination comprising a pulse responsive electromagnetically operated device which operates to drive an output member against a stop in response to an applied pulse and means to apply a first pulse to said device to drive said output member against said stop and to apply a second pulse to said device following said first pulse applied thereto after said output member has been driven against said stop while said output member is still moving, said second pulse having a polarity to oppose the kinetic energy of said output member and having insufficient inpulse content to drive said output member against said stop.
Claim 14
Dependent Claim
103 words
A combination comprising a pulse responsive electromagnetically operated device which operates to drive an output member against a stop in response to an applied pulse and means to apply a first pulse to said device to drive said output member against said stop and to apply a second pulse to said device following said first pulse applied thereto after said output member has been driven against said stop while said output member is still moving, said second pulse having a polarity to oppose the kinetic energy of said output member and having insufficient inpulse content to drive said output member against said stop.
Claim 15
Dependent Claim
26 words
A combination as recited in claim 13 wherein said second pulse is applied to said device while said output member is rebounding away from said stop.
Claim 16
Dependent Claim
53 words
A combination as recited in claim 14 wherein the ratio of the impulse content of said second pulse to that of said first pulse is approximately equal to the ratio of the velocity of said output member in rebounding from said stop to the velocity of said output member in striking said stop.
Claim 17
Dependent Claim
27 words
A combination as recited in claim 13 wherein the impulse content of said pulse is selected to approximately cancel out the kinetic energy of said output member.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-07-25 | 1976-01-24 | 1976-07-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-25 | 1980-01-24 | 1980-07-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-25 | 1984-01-24 | 1984-07-25 | $7700.00 | Window Closed / Lapsed |