Abstract: A hand-held printing calculator for printing calculating results on elongated paper strips from a bundle of paper strips disposed within the calculator is provided. The calculator includes a microprinter having a paper feeding assembly including feeding elements disposed before and after the print position and in the same plane as the advancing paper for maintaining the paper flat during printing. In another embodiment of the invention, a detection sensor detects the absence of a paper strip at the print position for generating a signal for feeding the next paper strip so that paper is continuously fed to the print position.

Abstract: An ink ribbon winding and reversing assembly suitable for use in a printer having two ratchet wheels for winding ink ribbon spools and an ink ribbon cassette having two rotatably mounted ink ribbon spools is provided. The assembly includes a feeding lever formed with opposed pawls for driving a first ratchet wheel in a first winding direction in response to displacement of the feeding lever. A detecting lever formed with a central arm disposed between the spools is biased towards the unwinding spool and causes the feeding lever to be displaced toward the unwinding spool at completion of winding thereon in response to the feeding lever shifting engagement to drive the second spool. This reversal process is repeated at completion of winding in each direction. The central arm of the detecting lever is formed with lateral guide surfaces for permitting engagement of an ink ribbon spool and an ink ribbon cassette with the detecting layer in a single snap-in motion.

Abstract: A light-weight micro-printer including a one piece molded plastic main frame is provided. The printer frame includes two substantially parallel side frames spaced apart from each other a distance of the width of a print paper with integrally molded support members between the side frames. The support members function as a paper guide member and isolate an electromagnet disposed within the frame.

Abstract: In a character-selecting mechanism for a printer, an electromagnet which controls the engagement and disengagement of a pawl with a ratchet and, thereby, the actual printing step, is supplemented with a permanent magnet having spaced-apart poles. A core arm lies within a core passage in the electromagnet and protrudes into the magnetic field produced by the permanent magnet. Activation of the electromagnet by a current pulse magnetizes the core arm to a polarity such that it is repelled by a pole next to which the core arm is disposed in a first position so that the core arm moves toward the other pole to take up a second position. During the transit from first to second position the core arm which is connected through a core member to a pawl brings the pawl into engagement with the ratchet.

Abstract: A small sized printer wherein the duration of the print cycle and the sequence of printing operations, during a print cycle, is controlled. The printer includes a plurality of print characters circumferentially disposed therearound, the print characters being selectively positioned in a print position by rotating the print ring from a rest position to a print position during each print cycle. A motor is adapted to be energized to rotate the print rings from a rest position to a print position during each print cycle. The instant invention is particularly characterized by a detection arrangement for detecting the rotary position of the print rings and generating a character selection timing signal representative of each of the rotational positions of the print ring.

Abstract: A print character selection mechanism for use with printers of the type wein print characters are circumferentially disposed about the character ring and are selectively positioned in a print position by deenergizing an electromagnetic coil is provided. Each of the character rings includes a ratchet gear having a plurality of circumferentially disposed teeth, which teeth correspond to print characters circumferentially disposed about the print character ring. The instant invention is particularly characterized by a comb-shaped yoke member having a plurality of selection yokes, associated with each of the character rings, and a common yoke supporting each of the selection yokes. An electromagnetic coil is disposed about each selection yoke and is normally energized to induce a flux field in the selection yoke. A plurality of selection members are normally disposed in a rest position in abutting engagement with a selection yoke when the electromagnetic coil is energized.

Abstract: A compact flying printer has a continuously rotating print drum and ratchet wheel, a trigger lever positionable to be struck by a tooth of said ratchet wheel and a hammer lever driven by said trigger lever and provided with a print hammer at its end. The trigger lever is formed with a linear guide portion for regulating the motion thereof and an energy-transmitting portion projected for transmitting energy from said ratchet wheel to said hammer level. Paper and ribbon are advanced by selective coupling of a transmitting member to a continuously rotating rotor operated in conjunction with the print drum.

Abstract: A compact flying printer has a continuously rotating print drum and ratchet wheel, a trigger lever positionable to be struck by a tooth of said ratchet wheel and a hammer lever driven by said trigger lever and provided with a print hammer at its end. The trigger lever is formed with a linear guide portion for regulating the motion thereof and an energy-transmitting portion projected for transmitting energy from said ratchet wheel to said hammer lever.