Abstract: To adjust the posture of a sheet being conveyed, movable checker members provided adjacent to the conveyance path for the sheet are once driven in the direction of conveyance of the sheet before the members touch the sheet and are subsequently decelerated, the members being caused to abut against the front end of the sheet during the deceleration, thereby checking the sheet and thus correcting any skew thereof. Further, for positioning the sides of the sheet, the sheet is taken out of a hopper by way of a separating device and is guided and fed in such a manner that its front corner will not be caused to abut against a side registration guide, and subsequently the sheet is conveyed toward the guide by way of obliquely extending conveyer belt devices and one side of the sheet is brought into contact with the guide for positioning after a front corner of the sheet has passed at least the edge of the guide.

Abstract: In a perfecting printing machine, a switch-back mechanism moves backwardly each sheet delivered out of the printing section, and a switching gate provided immediately after the switch-back mechanism selects a first sheet path to return the sheet whose one side has been printed to the printing section and a second sheet path so that the sheet whose both sides have been printed is delivered to the stacker after being moved backwardly by the switch-back mechanism.

Abstract: A type arrangement data editing apparatus in which type arrangement data from a type carrier is automatically edited in accordance with the carrier set carried by the type carrier. A first area of a ROM stores the basic type arrangement data for a plurality of basic character sets. A second area of the ROM stores replacement data which is replaced for specific symbols in the basic character sets, and the start addresses of the type arrangement data for each set. An identifier identifies which character set and which replacement data are carried on the type carrier. A microprocessor stores a program for retrieving the respective type arrangement data and inserting the replacement data therein. The data is sent to a RAM, where it is compared to input data to print a specific print symbol.

Abstract: A printing mechanism is provided with a counter-balanced hammer bank such that the hammer bank and a counterweight are oppositely reciprocated by a pair of cams mounted on a vertically oriented cam shaft. Vibration of the printer even at high speed can be eliminated by completely dynamically balancing the system.

Abstract: A dot printer in which vibration is eliminated without the use of a separate counterweight. The printer includes first and second hammer banks each holding a plurality of dot printing elements. The first and second hammer banks are spaced apart from each other a predetermined distance in the direction in which a printing sheet passes. A motor and oppositely-phased drive cams reciprocate the two hammer banks in opposite directions parallel to a dot printing direction.

Abstract: Systems for discriminating among a plurality of type carriers differing in number of characters and pitch of characters are disclosed. In one circuit, the type carrier is provided with synchronizing marks and discrimination marks in addition to the usual type character marks. The synchronizing mark is located at the beginning of a set of characters, and the discrimination mark is located a predetermined distance from the synchronizing mark according to the number of characters and pitch of the particular type carrier. This distance is determined by counting type character marks. In another circuit, one or more discrimination marks are provided between type character marks at the beginning of a set of characters. The number of discrimination marks indicates the number of characters of the particular type carrier. In either circuit, a counter of only a few stages and a simple decoding circuit are all that are required to carry out the discrimination operation.

Abstract: Systems for discriminating among a plurality of type carriers differing in number of characters and pitch of characters are disclosed. In one circuit, the type carrier is provided with synchronizing marks and discrimination marks in addition to the usual type character marks. The synchronizing mark is located at the beginning of a set of characters, and the discrimination mark is located a predetermined distance from the synchronizing mark according to the number of characters and pitch of the particular type carrier. This distance is determined by counting type character marks. In another circuit, one or more discrimination marks are provided between type character marks at the beginning of a set of characters. The number of discrimination marks indicates the number of characters of the particular type carrier. In either circuit, a counter of only a few stages and a simple decoding circuit are all that are required to carry out the discrimination operation.

Abstract: An apparatus for feeding a paper having holes utilizes an endless belt which contains a plurality of pins which are mounted so that they are positioned to a side of an outer periphery of the endless belt. The pins fit into holes in the paper to feed the paper as the endless belt is driven by two main pulleys. An auxiliary pulley is rotatably mounted on one of the shafts which supports one of the main pulleys in such a manner that the auxiliary pulley confronts and supports the bottoms of the pins, thus preventing the pins from being deflected inward. Because the auxiliary pulley is driven with one of the main pulleys, friction between the bottoms of the pins and the auxiliary pulley is minimized.

Abstract: A clamping device for a printer has a plurality of sideways-slippage preventing rollers housed in a roller housing which is fixed to a rear face of a wall of a ribbon shield. These preventing rollers prevent the printing paper from slipping sideways during a printing operation. A plurality of pressing plates are fixed on a hammer cover and biased towards the preventing roller by springs. A printing paper travels between the preventing rollers and the pressing plates, and the preventing rollers are oriented to rotate in the direction in which the printing paper travels. Since the preventing rollers prevent the printing paper from slipping sideways during printing, the printing lines are aligned properly. The preventing rollers also exert a minimum forward clamping force on the printing paper, which thus prevents the paper from tearing.

Abstract: A printing apparatus including a plurality of drive coils for driving printing hammers arranged longitudinally in side-by-side relation at one side of a core of the U-shape. A first cooling fluid passageway is defined inside the core of the U-shape to allow a cooling fluid for cooling the drive coils to flow therethrough, and a second cooling fluid passageway is defined outside the core by a duct to allow the cooling fluid for cooling the drive coils to flow therethrough without escaping to the outside by diffusion. A current of cooling fluid is forcibly fed into these cooling fluid passageways by a fluid machine.

Abstract: A printing mechanism is provided with a counter-balanced hammer bank such that the hammer bank and a counterweight are oppositely reciprocated by a pair of coaxial, identical, orthogonally oriented cams. Vibration of the printer even at high speed can be eliminated by completely dynamically balancing the system.

Abstract: An upper cover for a line printer in which an upper cover hood can be easily opened forwardly to permit full maintenance of the printing mechanism. The upper cover hood is pivotally coupled through a rear hinge holder to a forwardly-extending support member via a balance holder. A balancing mechanism is pivotally coupled at one end to the balance holder. At the front end of the support member a hook member is hingedly attached, the other end of which is adapted to be swung into position and coupled to a pin which is rigidly coupled to a side wall of the upper cover hood. A cushioning packing is disposed along the front edge of the upper cover hood.

Abstract: A hammer drive safety device for a line printer having a plurality of solenoid-driven hammers is disclosed, which includes a time limiting circuit for producing an output when a character print command signal is not produced for more than a predetermined duration, the plurality of detectors for detecting currents flowing through the respective solenoids, and a switch responsive to the output of the time limiting circuit and the outputs of the detector for disconnecting the solenoids from the power source.

Abstract: An impact printing apparatus of the back-impact or front impact type having a frame construction composed of first and second frame structures positioned in a fore-and-aft direction of the apparatus and having impact hammers mounted on one of the frame structures, and a tiltable member positioned on one side of the frame structures, wherein the first frame structure is pivotally connected to the tiltable member about a vertical axis along one side end of the first frame structure and the tiltable member in turn is pivotally supported on the second frame structure about an axis in a lateral direction of the printing apparatus.

Abstract: A printing apparatus comprising a type carrier to travel along a print line on a printing paper, a plurality of printing hammers to be selectively driven to strike the printing paper against an inking ribbon and the inking ribbon against a platen in front of the inking ribbon, and a support member supporting the type carrier, inking ribbon and platen thereon, wherein the support member is movable between a position holding the type carrier, inking ribbon and platen in positions capable of performing printing operation but intercepting the line of sight between the print line and the operator's eyes and a position holding the type carrier, inking ribbon and platen in inoperative positions but providing an unobstructed line of sight from the operator's eyes toward the print line for enabling the operator to clearly view the printed information along the print line.