US3586983A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Print hammer control system
Assignee: Momentum Systems Corp
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Filing: 1968-11-25
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Granted: 1971-06-22
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Expires: 1988-11-25
Abstract
Abstract A print hammer firing circuit incorporating secondary storage includes a Schmitt trigger, two logical AND circuits and a logical OR circuit. One of the AND circuits and the OR circuit are mutually interconnected input-to-output to provide the storage function and to drive the Schmitt trigger. The second AND circuit is connected to gate the trigger output under control of the storage circuit. An integrating network at the trigger input causes the gated output, which drives the hammer coil, to define an accurate hammer actuation time interval.
Inventors
- 👤 Lynn W Marsh Jr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 19:25
CPC Classifications
B; B41; B41J; B41J9/00; B41J9/44
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
293 words
A circuit for firing a print hammer in a high speed line printer comprising: a coil adapted to fire the hammer in response to a coil drive signal; a bistable circuit selectively settable to two different output states in response to voltage level transitions presented at its input, a transition of a first polarity switching said bistable circuit to a first of said two output states and a transition of the opposite polarity switching said circuit to the second state, said bistable circuit further including means for delaying said switching by a predetermined interval after occurrence of said oPposite transition; gating means connected to the output of said bistable circuit for generating, when open, a coil drive signal in response to said first output state of said bistable circuit; control means for causing said bistable circuit to switch into said first output state when said coil is to be driven at a subsequent instant, said control means comprising: a logical AND circuit and a logical OR circuit mutually connected outputto-input, means for presenting a signal to a second input of said OR circuit when the coil is to be driven at a subsequent instant, means for presenting a signal to a second input of said AND circuit at said subsequent instant, means for transmitting the output of said OR circuit to an input of said gating means, and means for transmitting the output of said AND circuit to the input of said bistable circuit; and means for causing said control means to simultaneously supply a voltage transition of said opposite polarity to said bistable circuit and to open said gating means at said subsequent instant, whereby said gating means generates a coil drive signal having a duration substantially equal to said predetermined interval.
Claim 2
Dependent Claim
293 words
A circuit for firing a print hammer in a high speed line printer comprising: a coil adapted to fire the hammer in response to a coil drive signal; a bistable circuit selectively settable to two different output states in response to voltage level transitions presented at its input, a transition of a first polarity switching said bistable circuit to a first of said two output states and a transition of the opposite polarity switching said circuit to the second state, said bistable circuit further including means for delaying said switching by a predetermined interval after occurrence of said oPposite transition; gating means connected to the output of said bistable circuit for generating, when open, a coil drive signal in response to said first output state of said bistable circuit; control means for causing said bistable circuit to switch into said first output state when said coil is to be driven at a subsequent instant, said control means comprising: a logical AND circuit and a logical OR circuit mutually connected outputto-input, means for presenting a signal to a second input of said OR circuit when the coil is to be driven at a subsequent instant, means for presenting a signal to a second input of said AND circuit at said subsequent instant, means for transmitting the output of said OR circuit to an input of said gating means, and means for transmitting the output of said AND circuit to the input of said bistable circuit; and means for causing said control means to simultaneously supply a voltage transition of said opposite polarity to said bistable circuit and to open said gating means at said subsequent instant, whereby said gating means generates a coil drive signal having a duration substantially equal to said predetermined interval.
Claim 3
Dependent Claim
220 words
In a high speed line printer, a circuit for driving a print hammer actuating coil comprising, in combination: a bistable circuit settable to a first and a second state; means for setting said bistable circuit to said first state when the coil is to be driven at a subsequent instant; means for generating a fire signal at said subsequent instant; means for resetting said bistable circuit from said first to said second state in response to said fire signal; and a timing circuit operable in response to said resetting of said bistable circuit for supplying a drive current to said coil for a predetermined length of time, said timing circuit comprising: a Schmitt trigger connected to the output of said bistable circuit; an integrating network connected to the input of said Schmitt trigger and constructed and arranged to present a rapidly changing voltage transition to switch said trigger to a first state in response to the setting of said bistable circuit and to present a slowly changing voltage transition to switch said trigger from said first to a second state in response to the resetting of said bistable circuit; and a coincidence circuit operable to supply said drive current to said coil only when said bistable circuit is in said second state when said trigger is in said first state.
Claim 4
Dependent Claim
220 words
In a high speed line printer, a circuit for driving a print hammer actuating coil comprising, in combination: a bistable circuit settable to a first and a second state; means for setting said bistable circuit to said first state when the coil is to be driven at a subsequent instant; means for generating a fire signal at said subsequent instant; means for resetting said bistable circuit from said first to said second state in response to said fire signal; and a timing circuit operable in response to said resetting of said bistable circuit for supplying a drive current to said coil for a predetermined length of time, said timing circuit comprising: a Schmitt trigger connected to the output of said bistable circuit; an integrating network connected to the input of said Schmitt trigger and constructed and arranged to present a rapidly changing voltage transition to switch said trigger to a first state in response to the setting of said bistable circuit and to present a slowly changing voltage transition to switch said trigger from said first to a second state in response to the resetting of said bistable circuit; and a coincidence circuit operable to supply said drive current to said coil only when said bistable circuit is in said second state when said trigger is in said first state.
Claim 5
Dependent Claim
208 words
In a high speed line printer, a circuit for driving a print hammer actuating coil comprising, in combination: a bistable circuit settable to a first and a second state, said bistable circuit comprising: a logical OR circuit having at least two inputs; a logical AND circuit having at least two inputs, a first one of which is connected to the output of said OR circuit; means for activating one of said OR inputs when the coil is to be driven at a subsequent instant; means for feeding the output from said AND circuit to the other of said OR inputs; and means for feeding said fire signal to the second one of said AND inputs, the output from said bistable circuit being manifested at the output of said OR circuit; means for setting said bistable circuit to said first state when the coil is to be driven at a subsequent instant; means for generating a fire signal at said subsequent instant; means for resetting said bistable circuit from said first to said second state in response to said fire signal; and a timing circuit operable in response to said resetting of said bistable circuit for supplying a drive current to said coil for a predetermined length of time.
Claim 6
Dependent Claim
208 words
In a high speed line printer, a circuit for driving a print hammer actuating coil comprising, in combination: a bistable circuit settable to a first and a second state, said bistable circuit comprising: a logical OR circuit having at least two inputs; a logical AND circuit having at least two inputs, a first one of which is connected to the output of said OR circuit; means for activating one of said OR inputs when the coil is to be driven at a subsequent instant; means for feeding the output from said AND circuit to the other of said OR inputs; and means for feeding said fire signal to the second one of said AND inputs, the output from said bistable circuit being manifested at the output of said OR circuit; means for setting said bistable circuit to said first state when the coil is to be driven at a subsequent instant; means for generating a fire signal at said subsequent instant; means for resetting said bistable circuit from said first to said second state in response to said fire signal; and a timing circuit operable in response to said resetting of said bistable circuit for supplying a drive current to said coil for a predetermined length of time.
Claim 7
Dependent Claim
214 words
A circuit for driving an actuating coil comprising: a bistable circuit adapted to be set to a first and reset to a second state; means for setting said bistable circuit in its first state when the coil is to be driven at a subsequent instant; storage means adapted to be Charged in response to setting of said bistable circuit and discharged in response to resetting of said bistable circuit; means for resetting said bistable circuit when the coil is to be driven; a Schmitt trigger responsive to said storage means, said Schmitt trigger being adapted to be switched to a first state in response to charging of said storage means and switched to a second state a period of time after discharge of said storage means is initiated; gating means for providing, when opened, a signal for driving the coil, said gating means adapted to be opened in response to the first state of said Schmitt trigger; and means, responsive to said bistable circuit, for, inhibiting said gating means when said bistable circuit is set in its first state, whereby said gating means provides a signal for driving the coil for the period of time beginning when said bistable circuit is reset and ending when said Schmitt trigger is switched to its second state.
Claim 8
Dependent Claim
214 words
A circuit for driving an actuating coil comprising: a bistable circuit adapted to be set to a first and reset to a second state; means for setting said bistable circuit in its first state when the coil is to be driven at a subsequent instant; storage means adapted to be Charged in response to setting of said bistable circuit and discharged in response to resetting of said bistable circuit; means for resetting said bistable circuit when the coil is to be driven; a Schmitt trigger responsive to said storage means, said Schmitt trigger being adapted to be switched to a first state in response to charging of said storage means and switched to a second state a period of time after discharge of said storage means is initiated; gating means for providing, when opened, a signal for driving the coil, said gating means adapted to be opened in response to the first state of said Schmitt trigger; and means, responsive to said bistable circuit, for, inhibiting said gating means when said bistable circuit is set in its first state, whereby said gating means provides a signal for driving the coil for the period of time beginning when said bistable circuit is reset and ending when said Schmitt trigger is switched to its second state.
Claim 9
Dependent Claim
75 words
The circuit as recited in claim 4 wherein said storage means is an integrating network connected to the input of said Schmitt trigger and adapted to present a rapidly changing voltage transition to switch said trigger to its first state in response setting of said bistable circuit and to present a slowly changing voltage transition to switch said trigger from said first to said second state in response to the resetting of said bistable circuit.
Claim 10
Dependent Claim
92 words
The circuit as recited in claim 4 wherein said bistable circuit comprises: a logical OR circuit having at least two inputs; a logical AND circuit having at least two inputs, a first one of which is connected to the output of said OR circuit; means for feeding the output from said AND circuit to one of the inputs of said OR circuit; and wherein: the other of said OR circuit is activated to set said bistable circuit, and the other input of said AND circuit is activated to reset said bistable circuit.
Claim 11
Dependent Claim
22 words
The circuit as recited in claim 4 wherein the coil is adapted to activate a print hammer in a high speed printer.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-06-21 | 1974-12-21 | 1975-06-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-06-21 | 1978-12-21 | 1979-06-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-06-21 | 1982-12-21 | 1983-06-22 | $7700.00 | Window Closed / Lapsed |