Abstract: High speed impact line printers comprise a continuously moving type carrier, such as an endless belt or band having engraved type characters movable at constant speed parallel to a row of print hammers. A print medium such as a continuous paper web and an ink ribbon are located between the hammers and the type carrier. The hammers are uniformly spaced parallel with the type carrier to define a print line. The spacing of the hammers corresponds to the desired spacing of the printed characters when printed and generally has one print hammer for each print position. An interposer member located between the print hammers and the print paper web enables certain characters such as vertical or horizontal bars of bar code type can be printed in the region of the clearance gaps between hammers.

Abstract: A tractor feed mechanism for feeding print forms comprises a continuous flexible pin belt wrapped around a pair of drive pulleys rotatably supported by a tractor body. Pins projecting from the flexible belt engage the forms via perforation in the forms. A door pivotally connected to the tractor body and is rotatable between an open condition in which paper can be placed on or removed from the pins and a closed position in which the forms can be restrained from becoming disengaged from the pins during feeding by the pin belt. A cam rotatable with the door and a spring is operable therewith produce a first restraining force on the door in its closed position which allows the door to be lifted a predetermined amount by the forms during feeding by the pin belt to accommodate variations in the thickness of the forms caused by buckling or folds.

Abstract: Apparatus for recording a displayed frame of video data by storing the binary data bits from identical segments of each video scan line, thereafter supplying the stored bits of the segments to a traversing matrix print head for recording the bits in those segments, and repeating the process with data bits from a different series of scan line segments. The number of data bits comprising a segment usually corresponds to the number of recording elements in the print head, and the number of print head excursions will vary inversely to the number of data bits in each segment. A resulting recorded video frame thus appears rotated 90.degree. with respect to the original frame orientation.

Abstract: Apparatus for adjustably positioning a supported transducer in sensing relation with recorded indicia on a shaft encoder in which a first frame portion is fixed and a second movable portion carrying the transducer is attached to the frame portion through a flexure means with the flexure means being on the opposite side of the shaft from the transducer and the movement of the transducer and path of indicia being at the same radius from the center of said shaft substantially decreasing the number of components formerly used, which enables highly accurate adjustments and lends itself to fabrication by molding.

Abstract: A tractor for feeding perforated paper has an endless belt of flexible material having pins and teeth extending in opposite directions from said belt. The belt has more rigid sections corresponding to the locations of the teeth between flexible web sections. A pulley is provided which has curved sections and grooves for receiving the teeth of the belt. The curved sections comprise an arc with ends having points of tangency with planes of straight sections of the belt extending across the grooves. The curved sections may comprise a composite arc having end arc sections with points of tangency with the planes of the straight sections of the belt and a center arc section having points of tangency with the end arc sections. The curved sections may also be an arc which has a continuously increasing radius of curvature from the points of tangency with the planes of the straight sections of the belt to a center line between the grooves.

Abstract: A printer control apparatus provides a control circuit arrangement which enables flight timing to be performed during printing. Basically, the invention achieves this by providing flight time control means activated by a print hammer operation signal. Preferably the control temporarily inhibits the continuation of print hammer operation. Preferably the control inhibits print hammer operation subsequent to a selected print hammer by inhibiting the comparisons of print line and type element data contained in storage devices of the print control. Inhibiting may be for a fixed interval based on an average of the flight times of all the hammers. Alternatively the inhibiting interval may be varied according to the individual flight times of the hammers. In order to avoid slowing the print speed excessively, only one hammer is timed during printing of one line.

Abstract: A feed mechanism for a printer having a door with hinge elements connected by hinge pins to the tractor body so as to be rotatable between first and second position. The hinge elements have rotary cams with convex and planar surfaces. A single flat steel spring is simply supported between its ends by a platform. The spring is held in flexed condition in a continuous bend by the platform and the cams of the hinge elements. The platform has coplanar support edges for simply supporting the spring. Alignment and centering means on the platform maintain the horizontal axis of the spring aligned with the common axis of the hinge pins and centered between the cams.

Abstract: A platen assembly for an impact printer comprises the combination of an impact transducer between the backup plate and the type band of a printer and an impact isolator interposed between the transducer and the type band. The transducer comprises a strip of force sensitive material. The strip extends over a plurality of print positions. Electrode means in contact with the surfaces of the force sensitive material form discrete impact zones aligned with the print hammers. One of the electrode means is a continuous conductive strip on one side of the force sensitive strip. Plural conductive pads on the other side of the strip form the discrete impact zones. The continuous conductive strip is preferably on the side facing the type band and serves as the ground connection. The impact isolation means comprises plural force elements between the type band and the transducer element and preferably is part of a comb which can be conductive and provides stiffening to the force sensitive strip.

Abstract: Method for controlling line printers comprising a revolving type band (400) and a print hammer bank for precalculating the firing times of the print hammers.The type band generally comprises equidistantly spaced scannable time marks (402) and a reference mark (501).The character spacing on the type band is subject to a coarse raster pitch .DELTA.T which is derived from the time mark pitch.The time mark positions are associated with coarse raster positions.The arrangement of the print hammers is subject to a coarse raster pitch .DELTA.T and a fine raster pitch .DELTA.T. Coarse and fine raster values are defined as time values.The hammers are sorted according to the fine raster values and their firing times are calculated by means of a special algorithm according to the order resulting from the sort step.

Abstract: A printer for printing both standard pitch and condensed pitch characters which includes print hammer faces which have a single wide section for standard pitch characters and a double wide section for printing condensed pitch characters. Using this hammer face one obtains the advantage of high speed when printing standard pitch characters and yet one is able to print condensed pitch characters with the same printer.The face of each hammer is divided into two sections. The first section of each hammer face is identical to the hammer face in a conventional single width hammer. The second section of each hammer face spans the width of two condensed pitch characters.The hammers are divided into two groups. The first group of hammers has the single width section on the top of the hammer face and the second group of hammers has the single width section on the bottom of the hammer face.

Abstract: The disclosure describes in detail one of the most serious problems in connection with maintaining the operating life of print hammers at the high speeds of todays printers. Also described in detail is a structural arrangement to solve this problem without involving a major redesign of a print hammer module. A significant aspect of this solution is that a high speed print hammer is kept out of contact with structure that serves as a reservoir for the pivot pin lubricant.

Abstract: Damping apparatus for minimizing print hammer settle time permits an increase in the hammer repetition rate, and in which the damping element is a reactive mass which is freely movable behind the actuated element to effect one or more energy transfer collisions with the actuated element. A return spring applies a return force to restore the actuated element and the reactive mass to a rest position. A bias spring, having an applied spring force which is lower than the return spring moves the reactive mass at a slower rate than the actuated element to cause the actuated element to collide with the reactive mass in advance of the rest position whereby the rebound energy of the actuated element is dissipated and restoration of the actuated element can occur as a result of the restore force applied by the return spring.

Abstract: Upon excitation of the electromagnet, a clapper armature is pulled into an operating gap, being increasingly additionally attracted by the pole of an electromagnet yoke leg.The motional plane of the clapper armature extends perpendicularly to the plane of the magnetic flux of the yoke structure of the electromagnet.

Abstract: A microprocessor provides to a main instruction source, A FIFO memory, various instructions (paper feed, hammer settings, . . . ) for a printer represented by instruction register thereof. For each instruction of the (A,C) type representing an operation code (C) for instance, a set command) for the hammer with address (A), address (A) is inputted into a secondary instruction source, a FIFO memory, simultaneously with a time information (Y) issued from a cyclic type binary counter. A so called mask bit (Z) which changes of value on every cycle, is also inputted, after complementation with time information (Y). When the contents (Y,Z) of counter and the contents (Y',Z) available from the output of source, are identical, comparator indicates to control unit that address (A') available from the output of source corresponds to the address of an hammer to be reset. Control unit adds code (C=RESET) and provides instruction (A', RESET) to register.