Abstract: An indexing double planetary gear train forms a portion of a feed system for accurately advancing a print media sheet through a printer. The planetary gear train has primary and secondary rings coupled to a sun gear by a series of planet gear clusters. Each planet gear cluster has primary and secondary planet gears which engage the respective primary and secondary rings. By assembling at least two of the gear train components to be fully indexing, and through the use of the identical planet gear clusters formed in a single mold, imperfections in the planet clusters and the rings, such as tooth-to-tooth defects or eccentricity, are canceled and have no effect on the accuracy of the line feed increments. Thus, more accurate and uniform media advance is achieved using plastic molded gears which are also relatively low in cost to manufacture and easy to assemble.

Abstract: In a line-spacing device for a typewriter or the like, where a platen, used as a support for the paper, is moved forward in steps by means of a ratchet it is provided for attaining a half-step transport that the gripper point (20) is seated longitudinally displaceable on the ratchet (11) in a direction approximately tangential to the toothed wheel (4) between two end positions determined by detent forces, where the detent force of the gripper point (20) is less than the force of resistance opposed by the toothed wheel (4) with the platen (1) to the drive by means of the gripper point (20) in the course of the tangential transport phase, and where the distance between the two detent end positions in the longitudinal direction corresponds to the tangential transport distance of a half transport step (t).

Abstract: Sensor arm (5) detects paper (1) at the printing stations of a printer (13). The sensor arm is linked through shaft (37) to position ledge (43) where it encounters and extension (47) of spring clutch (31) to decouple the spring clutch. Sheetfeed (11) is both driven and controlled from the platen (3) of the printer. With the spring clutch deactivated by the presence of paper, pawl (39) continues to hold the sheetfeed in an inactive status. In the absence of paper, the sensor arm (5) moves past the printing region, moving the ledge (43) away from contact with the spring clutch. Backward movement of the platen then initiates a sheetfeed cycle by movement of gear (35) being transmitted through the spring clutch (31).

Abstract: An apparatus for feeding recording paper forwardly and backwardly in a printing apparatus comprising a pair of paper feed devices, one on each side of a printing unit. The upstream paper feed device is lower in forward feed speed than the downstream paper feed device. The apparatus includes a larger- and a smaller-diameter gear portions provided integrally on a drive gear wheel which transmits a drive force to the upstream paper feed device. A reverse-feed gear wheel, mounted on the drive shaft, meshes with the larger-diameter gear portion via a one-way clutch. A forward-feed gear wheel, loosely fitted over the drive shaft, meshes with the smaller-diameter gear portion. A clutch spring, wound around the outer periphery of the shaft of the forward feed gear wheel and a seat coupled to the drive shaft, is engaged with a rotary body with a one-way clutch.

Abstract: A process for controlling line spacing, including the steps of clearing or setting line pitch variable mode in a first state; checking keyboard input in a second stage; determining whether the keyboard input indicates line pitch variable mode, and performing a function corresponding to keyboard input in a third stage if the keyboard input does not indicate line pitch variable mode; setting the length specified in a fourth stage if the keyboard indicates a specified length of line spacing; in a fifth stage, if the keyboard does not indicate a specified length in the fourth stage, returning the carriage through feeding by the length of the variable line pitch and returning to the first stage when the keyboard input in the fifth stage does not indicate a return function, line feeding by the length of the variable line pitch and returning to the first stage when the keyboard input indicates an index key; in a seventh stage, if the keyboard input in the sixth stage does not indicate an index key, performing a reve

Abstract: Disclosed is a printer having memory means for storing the vertical print position movement data so as to print a super-script or sub-script character. When the carriage is returned after printing in a nonstandard row position, the print position is moved down by an adjusted line feed amount based on the vertical movement data stored in the memory means.

Abstract: The sheet feeder can be mounted on a typewriter or on a printer in a system for processing data. The sheets which are accommodated in a feed magazine are passed to the platen roller by friction stripper rollers. After the printing operation, the sheets are passed on to a collection table positioned in front of the feed magazine. The stripper rollers are permanently connected to the platen roller by way of a mechanical transmission and rotate in the same direction as the platen roller. The stripper rollers are mounted on an oscillating arm to be selectively moved towards or away from the first sheet to be fed, by means of a first cam. Before a fresh sheet is fed, a second cam, also coupled to the platen roller, has to be brought to a reference position by rotating the platen roller enough to expel the current sheet. The platen roller is then rotated in the reverse direction, whereby the second cam actuates a lever, thereby to close a clutch.

Abstract: A paper sheet feeding apparatus includes paper sheet feed rollers of friction type which are unidirectionally driven through a clutch mechanism provided between the paper sheet feed rollers and a platen of a printer to feed, one by one, paper sheets to the platen. The clutch mechanism establishes a coupling relation between them when the platen is driven in a direction in which the paper sheet is taken therein, until a front end portion of the paper sheet is taken therein and then the coupling relation is released by driving the platen in the reverse direction slightly while the front end portion is retracted from the platen.

Abstract: A printer which is so constructed as to automatically detect deviation of a printing type when a deviation detecting command signal is detected and to automatically adjust paper feed immediately after a pause mode is released.

Abstract: The platen (11) is mounted between two side plates (9-10) of equipment which is hinged to two risers (5-6) to rotate about an axis .gamma. running parallel to the axis of the platen. The platen is provided with a freewheel mechanism including an inner ring (28) which is connected to the platen and an outer ring (29) which is provided with a peg (31) engaged in a slot (8) in a fixed member (7). The slot is situated on the opposite side of the platen axis .DELTA. relative to the axis of rotation .gamma. and in substantially the same plane. Detector means (36-37) for detecting the presence of a document in an insertion channel (17) cause the platen to rotate in the direction in which the freewheel mechanism drives the outer ring, thereby pressing the peg against the slot and rocking the equipment about the axis .gamma. thus allowing a document to pass between the print head and the platen until it meets an abutment (14) which is moved into place by the rocking action.

Abstract: A thermal color printer includes a reversible platen roller 9 and associated pinch rollers 11, 10 on the paper feed and discharge sides. The paper is repeatedly advanced back and forth through the printing station to successively print the different color separations. The discharge side pinch roller 10 is coupled to the platen roller by "unequal" spur gear 31, 32 and one-way clutches 33 such that it is frictionally driven by the platen roller in the sheet advance direction and gear driven by and at a slower speed than the platen roller in the reverse or sheet return direction. This serves to tension the sheet of paper during each return conveyance to thus maintain it in tight contact and registration with the platen roller, thereby avoiding offsets between the successive color separation printings and attendant fringe patterns.

Abstract: An electronic typewriter is provided with a function that the print head is moved leftward linearly when a backspace key is continuously operated after the printing paper is fed more than a preset amount, while the print head traces the printed characters when the printing paper is fed less than the preset amount. The typewriter is convenient in erasing a mistyped character on a printed line with a superscripted or subscripted character and also useful in printing new characters on the same fed printed line.

Abstract: A function for an electronic typewriter is described which allows the operator of the typewriter to realign the print element of the typewriter to the prior adjacent, or the following adjacent line which contains textual material, even when the present position of the print element is other than a uniform line feed increment or multiple thereof, from the designated destination line. The electronic controls of the typewriter determine the present position of the print element and the vertical location of the line to which the print element is to move, and determines the distance and moves the record sheet to position the print element precisely over the designated line of text.

Abstract: A printer is provided with a controllable bail located between a print station and a downstream paper tear-off station. Upon occurrence of a first control signal, a printed portion of the paper is advanced to a desired tear-off position adjacent the tear-off station. Thereafter (after a predetermined time delay or after operator switch actuation), the paper is retracted to a new first print line position at the print station. The intermediately located bail is released at least after the leading edge of the paper is retracted thereunder and until sufficient paper is again advanced (e.g. during new printing operations) to ensure that paper is again located between the printing platen and the bail before the bail is re-engaged.

Abstract: A thermal printer using a single pulse motor is disclosed. This thermal printer comprises: a single pulse motor; a moving member which is moved in accordance with the drive of the pulse motor; a head raising and lowering mechanism and a sheet feed mechanism which are selectively actuated in correspondence with the movement of the moving member; and a carriage moving mechanism which is interlockingly driven by the pulse motor. These components are driven by the single pulse motor. Also, the moving member may be a rack.

Abstract: A paper setting mechanism of a printer for setting a sheet of paper in position around a platen roller for printing desired information includes a paper bail assembly having at least one bail roller, which is pivotally supported and normally biased so as to cause the bail roller to be pressed against the platen roller. The paper bail assembly may be set in a set position in which the bail roller is pressed against the platen roller and it may also be set in a retracted position in which the bail roller is separated away from the platen roller. After insertion of paper, the platen roller is driven to rotate first in the normal direction over a first predetermined amount and then in the reversed direction over a second predetermined amount, which is smaller than the first predetermined amount, whereby the reversed rotation of the platen roller is utilized to cause the paper bail assembly to return to its set position automatically.

Abstract: A printing apparatus is disclosed which comprises a platen roller for feeding a cut paper sheet set on a hopper, a paper bail bar having paper bail rollers used in conjunction with the platen roller to secure the cut paper sheet against the platen roller, and a paper loading mechanism for loading the cut paper sheet by causing rotation of the platen roller at a predetermined angle. The paper loading mechanism includes a paper bail switch for checking whether the paper bail roller is in contact with the platen roller. When it is detected by the paper bail switch that the paper bail roller is released from the platen roller, the platen roller is rotated in the normal direction at a first predetermined angle. When, it is detected by the paper bail switch that the paper bail rollers are in contact with the platen roller, the platen roller is rotated in the reverse direction at a second predetermined angle.

Abstract: The present invention relates to a driving device of platen used in printing devices such as typewriters, printers, etc., which is equipped with a motor, a first gear adapted to transmit the output from this motor and provided with notches on part thereof, a second gear which is intermittently driven by continuous rotation of this first gear and a platen driven through this second gear. A pawl holds the platen in place, but allows manual rotation thereof.

Abstract: A paper feeder for use in dispensing paper into a printer with sensors for leading and trailing edges of paper and with a platen which rotates in a forward imprinting direction in response to a leading edge and in a backward, paper-ejecting direction in response to a trailing edge, the paper feeder comprising a paper holder, at least one rotatable drive roller to operably contact paper in the holder, and a drive train connecting the platen to the roller and controlled exclusively by such connection to cause no roller rotation in response to forward platen rotation, and to cause roller rotation in a paper-dispensing direction in response to backward platen rotation; the drive train is arranged so that the roller delivers paper to a paper-loading position on the printer not before the platen completes paper ejection; whereby backwards platen rotation provides simultaneous paper ejection and dispensing.

Abstract: A paper feed system in a printer includes a platen for supporting a recording paper sheet, a paper feed drive motor, and a transmission gear mechanism for transferring the rotation of the paper feed drive motor to the platen so as to conduct an automatic paper feed operation. The paper feed system further allows a manual paper feed operation wherein the platen is manually rotated. A detection system is provided which detects the manual paper feed operation. If the manual paper feed operation has been conducted before the automatic paper feed operation, a compensating paper drive is first conducted when an automatic paper feed instruction is developed. In the compensating paper drive, the platen is first driven to rotate in the reverse direction by a predetermined amount and, then to rotate in the forward direction by the same amount, thereby compensating for the displacement of the paper sheet location caused by the backlash of the transmission gear mechanism during the manual paper feed operation.

Abstract: A device for controlling the rotary movement of a platen roller of a typewriter comprises a bidirectional electric motor coupled to the platen by a worm gear and gear wheel and a pair of knobs which are disposed at the sides of the platen and which are rotatable with respect thereto. The knobs are fixed to a bar which extends rotatably through the platen roller and carries the gear wheel. Selective bidirectional rotation of the knobs causes corresponding rotary movement of a disc in a transducer. The disc has a toothed sector in mesh with the gear wheel and is the moving part of a rotary switch which generates electrical signals which determine both the power supply to the electric motor and the direction of rotation thereof. Small degrees of rotary movement of the knobs against a first spring force establish continuous rotary movement of the platen roller at low speed. A further slight rotary movement of the knobs against a stronger spring force establishes rotary movement of the platen at high speed.

Abstract: A line spacing mechanism for printing machines comprises an electric motor which is operable to rotate selectively in either direction. A worm on the shaft of the motor meshes with a helicoidally toothed wheel to cause a platen roller to rotate in the clockwise direction or the anticlockwise direction. The motor is support pivotally by trunions and urged by a spring to eliminate radial play between the worm and toothed wheel. Another spring, lever and ball apply thrust to the motor shaft to take up axial play in its bearing, i.e. between the worm and the motor.

Abstract: A printer such as a thermal printer includes a reversible motor, a paper feed driver angularly movable through a desired angle in response to operation of the motor, a paper feeder rotatable for feeding a sheet of paper, and an electromagnetic clutch operatively connected between the paper feed driver and the rotatable paper feeder. The electromagnetic clutch comprises a first yoke, a second yoke disposed in confronting relation to the first yoke normally in spaced relation thereto, and an exciting coil wound around one of the first and second yokes, the first yoke being coupled to the paper feed driver, the second yoke being coupled to the rotatable paper feeder, the arrangement being such that when the paper feed driver is turned in a direction to feed the sheet of paper, the exciting coil is energized to attract the first and second yokes magnetically to each other for thereby causing the paper feed driver to rotate the rotatable paper feeder to feed the sheet of paper through the electromagnetic clutch.

Abstract: A paper feeding apparatus for a printing device, comprising a rotational shaft connected through a one way spring clutch to a forward and reverse rotatable driving motor supported by the printing device, feed rollers mounted on the rotational shaft so as to be in pressure contact with the uppermost surface of pieces of printing paper stacked on a holder table, and a coil spring wound around the rotational shaft and supported at one end thereof by a frame for preventing the rotation in the other direction of the rotational shaft induced by the reverse rotation of the driving motor. The holder table is supported by the frame pivotally through an adjusting means utilizing an eccentric shaft.

Abstract: A multi-stage printer has an arithmetic section for calculating the next paper moving amount on the basis of a line position of a selected type stage of a plurality of type stages; printing is performed by a desired number of digits in a first line position by using first types selected from the groups of types; then, the distance from the printed first line position to a printed state-confirmable position away from the area opposed to the groups of types is calculated by the arithmetic section and the printing paper is moved by the paper moving means by an amount based on the result of the calculation thereby allowing the printed first line position to be moved up to the confirmable position; then, before printing in a second line position by using second types selected from the groups of types, the distance from the printed first line position now occupying the confirmable position to the second selected types is subtracted from a predetermined printing inter-line pitch in the arithmetic section and the pri

Abstract: A line spacing device for printing machines comprises an electric motor arranged to rotate selectively in a clockwise direction and anticlockwise direction and a control disc carrying a pawl on an eccentric. The tooth of the pawl describes a closed trajectory engaging in the teeth of a wheel and of a sense the same as the rotation of the disc, whereby a paper support platen is rotated by one increment in the opposite sense. A central control unit controls the clockwise and anticlockwise rotations of the electric motor. A cam disengages a detent pin from the wheel so that the motor is only lightly loaded when actuating the platen.

Abstract: A single drive mechanism providing selective feeding of at least two printing media and independent bi-directional movement of the media in the operation of a single print station. The drive mechanism including a platen member is movable to allow the two printing media to be positioned in the print station for a printing operation. The platen member is rotated in opposite directions to feed the two printing media to a printing position.

Abstract: In an advancing device for the motorized vertical displacement of a record carrier in an electrically driven office machine, which device includes an operating element mounted for movement in either one of two directions from a zero position, and members responsive to movement of the operating element in either one of its two directions for displacing such carrier in a respective vertical direction corresponding to the direction of movement of the operating element, the members are made to be responsive to movement of the operating element in at least one direction from the zero position for advancing the record carrier at a rate which increases as the extent of displacement of the operating element from the zero position increases.

Abstract: A record material feed apparatus for use with a printing machine of the type including a platen and drive means for rotating the platen about its longitudinal axis. The apparatus comprises a frame capable of being attached to a printing machine adjacent the platen thereof, first and second drive shafts each rotatably mounted on the frame, and first and second drive assemblies respectively mounted on the first and second drive shafts, each drive assembly including means for engaging a marginally punched record material loaded thereon and means for feeding said record material in response to the rotation of the respective drive shaft. Further, a drive assembly is mounted on the frame and includes means for engaging the platen drive means and means responsive to such engagement and the operation of the drive means for rotating the first and second drive shafts in opposite directions.

Abstract: The printer is provided for alternative use with long webs or individual, precut forms; it includes two friction roll drives adjacent to the print head and platen, and a sprocket drive upstream, being permanently engaged with a perforated web. The drives operate in synchronism but do not participate in all operations. Printing on the web is carried out after advancing the web by one form length and retracting it during stop and go printing. Switches control access to a bypass, the insert for a single form, and a receiver tray, into which any printed form drops.

Abstract: According to a representative embodiment of the invention, a parallel line printer such as a thermal printer is provided having a parallel printing head with a plurality of printing elements arranged to extend across the width of a paper strip. Electrical signals representative of characters to be printed can be stored in a storage device having a capacity corresponding to a full line of characters, and a print control logic is operative to cause the printing head to print up to a full line of characters simultaneously, or substantially so, in response to a print command. Means are provided to permit printing to be resumed on a line already containing characters printed in response to certain print commands. In the case when the paper is typically moved forward after one line has received print, means are provided to return such line back under the printing head if printing must resume on such line.

Abstract: A control for platen rotation in printers, and particularly in telex machines where the platen rotation drive, either a stepping motor or a DC motor, is provided with an incremental control actuated by keyboard keys to advance or counter advance the platen by a small increment of the full line space whereby alignment of the imprinting line with form spaces is facilitated.

Abstract: A device is disclosed for index and exponent impression printing in typewriters. An exponent or index switching key has associated with it an edge detector, and parallel thereto, a state detector. A time function element which triggers a gate circuit for the triggering of the drive motor for the roller is connected behind the edge detector. A rotational direction reversal switching device is connected behind the state detector. The device is useful in office typewriters, data printers or telex machines not equipped with their own exponent or index printing symbols.

Abstract: The accurate and uniform indexing of paper business forms with line hole punched margins. The index drive overcomes any possible accumulation of errors. A pawl and ratchet device is employed in the feeding of the paper form. The ratchet is rotated approximately one-half tooth beyond the ultimate desired stop. A spring urged arm then pulls the ratchet wheel back that one-half tooth turn so the pawl rests solidly in a single ratchet tooth. It is this same spring arm that pulls back the over-fed paper form. The form pull back is permitted by reason of a magnetic one-way clutch being momentarily released at the end of the mechanical feed-out. The present device is a combination of a mechanical drive with a magnetically releasable clutch to effect a constantly accurate feed out of paper forms resulting in identical positioning of each of the series of continuous paper forms.