GB1299131A - Selective recording unit - Google Patents

Abstract

1299131 Selective printing NORTRON Inc 2 March 1970 [20 March 1969] 9977/70 Heading B6F Hammer impression.-A selective printer having an inertia driven hammer assembly includes a rotatable non-circular shaft 62 controlled by a clutch 66 and a brake 76, the clutch, when energized coupling a drive motor 64 to the shaft 62. The shaft 62 drives a rotary inertia gear element 80 mounted on a shaft 84 fixed to the impression hammer 56, through a gear 78 mounted on the shaft 62. The hammer 56 pivots about the axis of the shaft 62, so that upon locking of the shaft 62 and the inertia gear element 80, a force is produced which swings the hammer 56 into contact with one of the type-carrying arms of rotating type disc 50. Re-engagement of the drive via clutch 66 causes the hammer to return due to the force caused by the acceleration of the inertia gear element 80. The type disc 50 is driven by the shaft 62 via bevel gears 86, 88, and normally rotate at a speed which will cause smearing. Retardation of the shaft 62, however, also causes retardation of the disc 50 so that upon the timed impact of the hammer, the disc is rotating at an acceptable "no smear" speed. The position of rest for the hammer is adjusted with a pin member (128, Fig. 4), and the force with which the hammer strikes the type disc is controlled by a resilient element (122, Fig. 4). In the particular embodiment, continuous stationary is fed over the platen (14, Fig. 2) and the combined type and hammer carriage 40 moves along the shaft 62 for letter spacing. As an alternative, the platen could move, with the carriage stationary.