EP0083694A2
Expired / Lapsed
EP
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Control system for timing hammers of impact printers
Assignee: International Business Machines Corp
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Filing: 1982-10-14
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Granted: —
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Expires: 2002-10-14
Abstract
Abstract A hammer timing control system for a line printer has a register for continually storing a digital delay fire quantity representative of the actual flight of a controlled hammer. A delay fire counter activated by an initiate fire pulse from hammer selection circuitry of the printer control system counts the timing pulses from a clock means until it registers a count equal to the delay quantity stored in the delay fire register. A comparator circuit is connected to both the delay value register and the counter and generates a hammer fire signal when the delay quantity and the count are equal. The single counter continues counting clock pulses until a second count is registered which is equal to a terminate fire value. The control system provides circuit means responsive to the second count registered in the counter to terminate the hammer fire signal. In one embodiment, the terminate fire circuitry comprises a decode connected to the output of the counter means for detecting the second count condition. In a second embodiment, the control system has a second register which stores a terminate fire quantity which represents a fixed time after the initiate fire signal and prior to hammer impact. In a third embodiment, the counter is an up/down counter which counts in one direction to turn on the hammer driver circuit and in the other direction to turn off the hammer driver circuit. The delay fire quantities for the plurality of hammers are preferably stored in an external memory device for transfer to the individual registers for each of the print hammers. The external storage may be a magnetic record such as a disk.
Inventors
- 👤 Douglas Allan Dayger
- 👤 Michael David Hryck
- 👤 Dean William Skinner
- 👤 Gerald Ralph Westcott
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 19:48
CPC Classifications
B; B41; B41J; B41J9/00; B41J9/44; B41J9/46
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
209 words
A system for timing the impact of a set of hammers (17) in an on-the-fly high speed line printer with the alignment of type (25) of a moving type carrier (26) with said hammers, said hammers each being driven by actuating means (10) energizable by firing pulses, said hammers having inherent flight times which may differ relative to a predetermined flight time, the combination comprising pulse generation means (40) for selectively supplying initiate fire pulses at a fixed predetermined time preceding impact for selectively driving said print hammers, and flight time control means (30) responsive to said initiate fire pulses for timing the energization of said actuating means relative to said alignment of said type in accordance with said inherent flight time including a source (31) of regularly recurring.timing pulses, counter means (51) operable in response to said initiate fire pulses for counting said timing pulses, register means (50) for storing variable delay values representing a predetermined number of timing pulses related to said inherent flight times of corresponding print hammers, and circuit means (52, 68) for providing time delayed fire pulses to said actuating means in response to the coincidence of a timing pulse count in said counter means corresponding with said delay values in said register means.
Claim 2
Independent Claim
209 words
A system for timing the impact of a set of hammers (17) in an on-the-fly high speed line printer with the alignment of type (25) of a moving type carrier (26) with said hammers, said hammers each being driven by actuating means (10) energizable by firing pulses, said hammers having inherent flight times which may differ relative to a predetermined flight time, the combination comprising pulse generation means (40) for selectively supplying initiate fire pulses at a fixed predetermined time preceding impact for selectively driving said print hammers, and flight time control means (30) responsive to said initiate fire pulses for timing the energization of said actuating means relative to said alignment of said type in accordance with said inherent flight time including a source (31) of regularly recurring.timing pulses, counter means (51) operable in response to said initiate fire pulses for counting said timing pulses, register means (50) for storing variable delay values representing a predetermined number of timing pulses related to said inherent flight times of corresponding print hammers, and circuit means (52, 68) for providing time delayed fire pulses to said actuating means in response to the coincidence of a timing pulse count in said counter means corresponding with said delay values in said register means.
Claim 3
Dependent Claim
54 words
A system for timing the impact of a set of hammers (17) in accordance with claim 1 in which said counter means (51) is further operable by timing pulses from said source (31) for controlling the duration of said fire pulses provided by said circuit means (52, 68) to energize said actuating means (10).
Claim 4
Dependent Claim
114 words
A system for timing the impact of a set of print hammers (17) in accordance with claim 1 in which said circuit means (52, 68) for providing said time delayed fire pulses comprises comparison circuit means (52) connected to said register means (50) and said counter (51) means for comparing said delay value and said time count and for generating an equal compare signal, and switch means (68) responsive to said equal compare signal from said comparison circuit for providing said time delayed fire pulses to said actuating means (10), and operating circuit means (14) connected to said switch means to be turned on by said fire pulses for energizing said actuating means (10).
Claim 5
Dependent Claim
79 words
A system for timing the impact of a set of hammers in accordance with claim 3 in which said counter means (51) is operable for counting said timing pulses to a second count condition, said switch means (68) is operable in response to said second count condition of said counter means for terminating said fire pulses, and said operating circuit means (14) is connected to said switch means to be turned off by the termination of said fire pulses.
Claim 6
Dependent Claim
73 words
A system for timing the impact of a set of hammers in accordance with claim 4 in which said switch means (68) is a bi-stable switch circuit operable to a first stable state by said compare equal signal from said comparison circuit (52) for turning on said operating circuit (14) and to a second stable state in response to said second count from said counter means for turning off said operating circuit means.
Claim 7
Dependent Claim
81 words
A system for timing the impact of a set of hammers in accordance with claim 5 in which said bi-stable switch circuit means (68) comprises a latch means having a set input connection (5) to receive said compare equal signals from said comparison circuit means (52) and a reset input (R) connected to be responsive to said second count condition of said counter means (51) and an output (Q) connected for supplying said fire pulses to said operating circuit means (14).
Claim 8
Dependent Claim
67 words
A system for timing the impact of a set of hammers in accordance with claim 4 in which said counter means (51) is a bi-directional counter operable in one direction for supplying said time count to said comparison circuit means (52) and in a second direction for counting said timing pulses to said second count condition for operating said switch means (68) for terminating said firing pulse.
Claim 9
Dependent Claim
50 words
A system for timing the impact of a set of hammers in accordance with claim 7 in which said bi-directional counter (51) is turned off in response to said equal compare signal from said comparison circuit (52) and is turned on for counting said timing pulses in said second direction.
Claim 10
Dependent Claim
59 words
A system for timing the impact of a set of hammers in accordance with claim 8 in which said bi-directional counter (51) is an up/down counter operable in an up direction for counting a first count for comparison by said comparison circuit means (52) and in a down direction for counting said second count for terminating said fire pulse.
Claim 11
Dependent Claim
57 words
In a system for timing the impact of a set of hammers in accordance with claim 9 in which said first and second counts are equal to said delay value in said register means (50), and said counter means (51) is interrupted between said counts for a predetermined interval relating to said flight times of said hammers.
Claim 12
Dependent Claim
119 words
A system for timing the impact of a set of hammers in accordance with claim 2 in which said counter means (51) is further operable by timing pulses from said source to a second count condition for controlling the duration of said fire pulses provided by said circuit (52, 68) means to energize said actuating means (10), said flight time control further includes second register means (53) for storing a terminate value representing a perdetermined number of timing pulses for controlling the duration of said fire pulses, and said circuit means is further operable for terminating said fire pulses in response to said second count in said counter means corresponding with said terminate value in said second register means.
Claim 13
Dependent Claim
65 words
A system for timing the impact of a set of hammers in accordance with claim 11 in which said terminate value stored in said second register means (53) represents a predetermined number of timing pulses corresponding to a fraction of the total flight time of said hammers (17) from a position of rest into impact relation with said type (25) of said type carrier (26).
Claim 14
Dependent Claim
98 words
A system for timing the impact of a set of hammers in accordance with claim 12 in which said actuating means (10) energizable by said firing pulses includes an actuator element (15) and an impact element (18) propelled thereby from said rest position into said impacting relation with said type (25), said actuator element being movable a distance which is a fraction of the flight of said hammer element (17), and said terminate value stored in said second register means (53) corresponds to a time duration at least equal to the time of motion of said actuator element.
Claim 15
Dependent Claim
92 words
A system for timing the impact of a set of hammers in accordance with claim 13 in which said actuating means (10) is an electromagnet (13) having a core (12) and coil means (11) and said actuator element (15) includes an armature movable upon energization of said coil means for propelling said impact element (18), said armature being movable said fractional distance to a seal position, and said terminate value represents a time duration corresponding with at least the time for said armature to move from said rest to said seal position.
Claim 16
Dependent Claim
65 words
A system for timing the impact of a set of hammers in accordance with claim 12 in which said terminate value stored in said second register means (53) represents a predetermined number of timing pulses for controlling the duration of said fire pulses whereby said circuit means (52, 68) terminate said fire pulses at a fixed time prior to impact by said print hammers (17).
Claim 17
Dependent Claim
57 words
A system for timing the impact of a set of hammers in accordance with claim 4 in which said counter means (51) is a wraparound counter operable by said timing pulses from said source for completing at least one wraparound operation to said second count condition for operating said switch means (68) for terminating said fire pulse.
Claim 18
Dependent Claim
44 words
A system for timing the impact of a set of hammers in accordance with claim 16 in which said wraparound counter (51) is operable for completing a second wraparound operation to a third count condition for producing a signal indicating a hammer settle condition.
Claim 19
Dependent Claim
78 words
A system for timing the impact of a set of print hammers in accordance with claim 1 in which said flight time control means further includes circuit means (14) for energizing said actuating means (10) at a plurality of different energy levels for different thicknesses of a print medium (23), and means (38) for altering said delay values stored in said register means (50, 53) to adjust for changes in said energy level of said actuating means (10).
Claim 20
Dependent Claim
46 words
A system for timing the impact of a set of print hammers in accordance with claim 18 in which said delay value stored in said delay register means (50) is altered by an amount equal for all print hammers for any one of said energy levels.
Claim 21
Dependent Claim
55 words
A system for timing the impact of a set of print hammers in accordance with claim 1 which further includes storage means for storing predetermined delay values corresponding with each of said hammers, and means (38) for transferring said delay values from said storage means to individual delay register means (50) for corresponding hammers (17).
Claim 22
Dependent Claim
32 words
A system for timing the impact of a set of print hammers in accordance with claim 20 in which said storage means is a central storage device controllable by a data processor.
Claim 23
Dependent Claim
57 words
A system for timing the impact of a set of print hammers in accordance with claim 21 in which said storage means is a read/write storage device for storing said delay values for said set of hammers (17) supplied to said data processor for transfer to said delay register means (50) for individual ones of said hammers.
Claim 24
Dependent Claim
33 words
A system for timing the impact of a set of print hammers in accordance with claim 21 in which said storage means is a read only storage device controllable by said data processor.
Claim 25
Dependent Claim
33 words
A system for timing the impact of a set of print hammers in accordance with claim 23 in which said read only storage device is a disk recorder controllable by said data processor.
Claim 26
Dependent Claim
64 words
A system for timing the impact of a set of print hammers in accordance with claim 1 which further includes means for altering said delay values stored in said register means (50) comprising a manual input device operable for keying changes in said delay value to said delay register means for altering said delay value for particular ones of said set of hammers (17).
References Cited (Backward Citations)
No citation records indexed.
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