摘要:
A feed arrangement for a typing ribbon and/or a correction ribbon comprises a linear motor having a coil-carrying slide which is movable with an alternating rectilinear movement, a toothed wheel for the feed movement of the ribbon, and a connecting mechanism interposed between the coil-carrying slide and the wheel for converting the movement of the slide into a unidirectional rotary movement of the wheel for advancing the ribbon. The connecting mechanism comprises a first lever which is moved by the slide and two mutually independent ratchet assemblies and which are capable of alternately engaging with two diametrally oppositely disposed teeth on the toothed wheel. The ribbon is carried by a cassette and the wheel rotates a blade capable of engaging into a seat in a feed roller of the cassette.The linear motor is of the type comprising a permanent magnet of cylindrical shape, a ferromagnetic core which is coaxial with respect to the magnet and which surrounds the permanent magnet and defines a radial air gap with the permanent magnet, and a winding which is accommodated in the air gap and is supported by the coil-carrying slide. The slide is capable of bidirectional movement coaxially with respect to the permanent magnet in response to bidirectional excitation currents in the winding, coming from an actuation circuit which in turn is controlled by a central unit of the machine.
摘要:
An electronic typewriter has a reduced number of electrically-powered actuators and comprises a motor powering a differential motion transmission unit having first and second output members. Transmission control means powered by a solenoid moves a slider to engage stop members selectively with the first and second output members to permit the second and first output members respectively to rotate. The first output member drives the carriage transport mechanism. The second output member drives the character carrying element and also powers function devices, namely a correction device, through a motion switching mechanism controlled by a switch control mechanism including another solenoid. The typing ribbon feed is driven by reciprocation of the slider between its two states. The motor is mounted on the frame and drives the motion transmission unit on a carriage through a belt; it also drives a line spacing mechanism through a clutch operated by a further solenoid. The motor and solenoids as well as the print hammer are controlled by an electronic controlling arrangement. In other alternative arrangements the motor is mounted on the carriage. A change mechanism controls the output of the motion switching mechanism so that it is applied to the correction device or to the line spacing device depending upon the direction of rotation of the motor. Instead of using a solenoid, the motion switching mechanism is engaged by a friction device driven from the first output member by driving the first output member backwards by one step. The motion switching mechanism is coupled to the line spacing device by a splined bar.