EP0124382A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Print hammer assembly for an impact printer
Assignee: NCR Canada Ltd
•
Filing: 1984-05-02
•
Granted: —
•
Expires: 2004-05-02
Abstract
Abstract A print hammer assembly for an impact printer includes a hammer (19) having a head portion (47) positioned at one end of a beam (39) which is mounted at a pivot (41) for movement of the hammer between a rest position and a print position. Operation of the hammer (19) is controlled by first and second windings (11, 13) wound around two cores (15, 17) respectively positioned adjacent two flanges (43, 45) of magnetic material provided on the beam (39) on either side of the pivot (41). A drive pulse applied to the first winding (11) pivots the hammer (19) to its print position and a restoring pulse applied to the second winding (13) restores the hammer to its rest position, the restoring action being assisted by a spring (63). In order to avoid interference between the magnetic fields produced by the two windings (11,13) the two cores (15, 17) are spaced apart and the drive pulse is arranged to terminate before the commencement of the restoring pulse.
Inventors
- 👤 Ali Tazammul Mazumder
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-30 14:20
CPC Classifications
B; B41; B41J; B41J9/00; B41J9/26; B41J9/38; B41J9/16; B41J9/24
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
240 words
A print hammer assembly for an impact printer, said assembly including a print hammer (19) mounted at a pivot (41) for movement of the hammer between a rest position and a print position, first and second core members (15, 17) of magnetic material each positioned adjacent a magnetic body portion (39) of said hammer, first and second windings (11, 13) respectively wound around said first and second core members, and generating means (83, 85, 97, 99) arranged to generate first and second pulses (73, 77) for energizing said first and second windings respectively, energization of said first winding (11) by a said first pulse serving to impel a head portion (47) of said hammer towards a print position and energization of said second winding (13) by a said second pulse serving to impel said head portion (47) towards a rest position, characterized in that said first and second core members (15, 17) are respectively positioned adjacent first and second magnetic body portions (43, 45) of said hammer (19), said body portions being spaced apart with one of them being disposed between said pivot (41) and said head portion (47), and with the other one being disposed on that side of said pivot (41) remote from said head portion (47), and in that said energizing means is arranged to generate said first and second pulses such that a said first pulse terminates prior to the commencement of a said second pulse.
Claim 2
Dependent Claim
240 words
A print hammer assembly for an impact printer, said assembly including a print hammer (19) mounted at a pivot (41) for movement of the hammer between a rest position and a print position, first and second core members (15, 17) of magnetic material each positioned adjacent a magnetic body portion (39) of said hammer, first and second windings (11, 13) respectively wound around said first and second core members, and generating means (83, 85, 97, 99) arranged to generate first and second pulses (73, 77) for energizing said first and second windings respectively, energization of said first winding (11) by a said first pulse serving to impel a head portion (47) of said hammer towards a print position and energization of said second winding (13) by a said second pulse serving to impel said head portion (47) towards a rest position, characterized in that said first and second core members (15, 17) are respectively positioned adjacent first and second magnetic body portions (43, 45) of said hammer (19), said body portions being spaced apart with one of them being disposed between said pivot (41) and said head portion (47), and with the other one being disposed on that side of said pivot (41) remote from said head portion (47), and in that said energizing means is arranged to generate said first and second pulses such that a said first pulse terminates prior to the commencement of a said second pulse.
Claim 3
Dependent Claim
27 words
A print hammer assembly according to claim 1, characterized by means (63) connected to said print hammer (19) for biasing said print hammer towards its rest position.
Claim 4
Dependent Claim
51 words
A print hammer assembly according to either claim 1 or claim 2, characterized in that the distance (P L ) between said head portion (47) and said pivot (41) is greater than the distance (T L ) between said other one (43) of said body portions (43, 45) and said pivot.
Claim 5
Dependent Claim
47 words
A print hammer assembly according to claim 3, characterized in that the distance (P L ) between said head portion (47) and said pivot (41) is approximately twice the distance (T L ) between said other one (43) of said body portions (43, 45) and said pivot.
Claim 6
Dependent Claim
30 words
A print hammer assembly according to any one of the preceding claims, characterized in that said first winding (11) has a greater number of turns than said second winding (13).
Claim 7
Dependent Claim
69 words
A print hammer assembly according to any one of the preceding claims, characterized in that said print hammer (19) comprises a beam (39) at one end of which is located said head portion (47), said beam being provided with first and second flanges which respectively constitute said first and second magnetic body portions (43, 45) and one of which is located at the other end of said beam (39).
Claim 8
Dependent Claim
49 words
A print hammer assembly according to any one of the preceding claims, characterized in that, with said print hammer (19) in its rest position, the distance between said head portion (47) and a type member (57) against which said head portion impacts in operation is at least 2.3 millimetres.
Claim 9
Dependent Claim
34 words
A print hammer assembly according to any one of the preceding claims, characterized in that said generating means includes means (85) for developing a current regulated first pulse for energizing said first winding (11).
Claim 10
Dependent Claim
63 words
A print hammer assembly according to any one of the preceding claims, characterized in that said generating means includes first circuit means (83, 85) for developing a first pulse for energizing said first winding (11), and second circuit means (97, 99), responsive to said first circuit means and including delay means (97), for developing a second pulse for energizing said second winding (13).
Claim 11
Dependent Claim
23 words
A print hammer assembly according to any one of the preceding claims, characterized in that said assembly is arranged to print MICR characters.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.