| 摘要 |
1,249,769. Selective printing. NATIONAL CASH REGISTER CO. 28 July, 1970 [25 Aug., 1969], No. 36378/70. Heading B6F. [Also in Division H1]. A print hammer actuator assembly 10 comprises a permanent magnet 18 which normally holds a pivoted actuator member 26 against the force of a spring 36 biasing the actuator member 26 towards an operative position, the magnetic flux path then being via arms 20, 24 of the magnet 18 and arm 28 of the member 26, the actuator member 26 being triggered by generation of a cancelling magnetic field is a coil 42, the magnetic flux path being thereby switched to include the arm 24 and an arm 22 of the magnet 18, and an arm 30 of the member 26. The switching of the magnetic flux path prevents production of stray magnetic fields and rebound of the actuator member 26 after striking the hammer 12. The actuator member 26 is reset by a bail 46. An adjacent assembly may be of an alternative form shown at 52 for compactness. |
