Mannesmann Tally Corporation

Tally LLC

Tally Printer Corporation

Edward D Bringhurst

John L Marshall

David G Starr

Swend L Miller

Verivada Chandrasekaran

Richard E Wagner

An integrally-formed print element for providing finer dots than previously possible with an impact printer. The dots produced permit the printing of Chinese, Amharic, Devanagari, and like characters, in sizes as small as standard newsprint, and print in books and periodicals, without significant distortion of the characters. The print element has an axis of symmetry and includes in order a cylindrical base with a longitudinal axis corresponding to the axis of symmetry of the print element; a frusto-conical-shaped impact element support with its largest diameter end extending from one end of the cylindrical base; and a cylindrical impact element located on and extending integrally from the other end of the frusto-conical-shaped support. The overall size of the print element is preferably such that it is attachable to standard impact printer hammer tips.

Printer element

A method and apparatus for extending the useful life of a printing ribbon by controlling the ratio of ink used to ink applied to the ribbon, while maintaining visual clarity of printed characters. A counter accumulates the number of characters printed, and the print density, over a preset period of time. The number of characters printed is compared with predetermined triggering numbers of characters, and the print density is likewise compared with a predetermined triggering print density. As a result of this comparison, the speed of the printer ribbon is increased to allow an increase in the ratio of ink applied to ink used, when the number of characters and print density are high. Conversely, ribbon speed is decreased when the number of characters printed during the preset time period, and the print density, are low, to prevent overinking and fouling of printer hammers. This condition applies when the ribbon is relatively new.

Method and system for controlled inking of printer ribbons

Stored energy print hammer actuators (11) having high efficiency coil posts (19) are disclosed. The coil posts (19) include a cylindrical core (33) mounted on a pin (35). The cylindrical core (33) has high resistivity and, thus, minimizes eddy currents and the power losses created by eddy currents. The cylindrical core (33) also has low hysteresis loss. In one form, the core (33) is formed of layers of a high resistivity material shaped to prevent eddy currents from circulating about the circumference of the posts. Suitable shapes include discrete C-layers and continuous spiral layers. Preferably, the layers are coated with an electrical insulating material that prevents cross-lamination eddy current flow. In another form, the core is formed of a high resistivity homogenous material, such as a ferrite material or a magnetic powder and an adhesive binder.

High efficiency coil posts for print hammer actuators

A print head for a dot matrix serial printer, including a high energy permanent magnet (13) surrounded by a plurality of coil/post combinations (15, 17) each aligned with a print hammer (23), is disclosed. The high energy permanent magnet (13) is centrally mounted on a ferromagnetic base plate (11) having a plurality of outwardly extending arms (41). A coil/post combination (15,17) is mounted on each arm (41). The coil/post combinations (15,17) are surrounded by an apertured spacer ring (19) formed on a nonmagnetic material. The hammers (23) are formed by the inwardly extending arms of a print hammer disc (21) mounted on the spacer ring (19) such that a hammer (23) is aligned with each coil/post combination (15,17). The tips of the hammers overly a stepped pole (25) mounted on the outer end of the high energy permanent magnet (13). When the coils (15) are deenergized, the magnetic flux produced by the permanent magnet (13) stresses the hammers (23) by pulling them against the tips of their related posts (17). While pulled toward the stepped pole, the hammer tips remain spaced therefrom. The hammers and the stepped pole (25) are sized, configured and positioned such that the tips of the hammers lie in the step region (109) of the stepped pole (25). As a result, magnetic flux flowing between the stepped pole (25) and the hammer tips is split between two main paths, one lying generally orthogonal to the plane of the hammers and the other lying generally coplanar with the plane of the hammers. Energization of any coil (15) by a pulse of appropriate polarity and magnitude cancels the magnetic force pulling the related hammer (23) against the related post (17), releasing the hammer (23). The stored energy created by stressing the hammer (23) causes the hammer (23) to press an associated dot printing wire (27) against a ribbon resulting in the printing of a dot on a print receiving medium. Termination of the coil energization pulse results in the hammer (23) being reattracted to its related post (17). Splitting the magnetic flux at the stepped pole (25) reduces the magnetic force at the stepped pole, allowing the hammers (23) to be more readily released.

Permanent magnet, stored energy, print head

An actuating mechanism includes a magnetic circuit formed by a permanent magnet (43), a flux plate (45), a return plate (47), a post (49), and a long release coil (51). The outer end of the release coil (51) terminates slightly short of the tip of the post. Further, the post (49), long coil (51), flux plate (45) and return plate (47) are sized and positioned such that the tip of the post (49) lies coplanar with the outer surface of the return plate (47) and such that the end of the return plate (47) terminates just short of the release coil (51). The head (59) of a hammer (53) is positioned to be attracted to the post tip by the magnetic flux created by the permanent magnet (43). The permanent magnet attraction force bends the head (59) of the hammer (53) across the small gap resulting in the hammer (53) being cocked. When the long release coil (51 ) is energized, it produces a magnetic field that counteracts the permanent magnet attraction force, releasing the cocked hammer. Release of the cocked hammer impacts a ball (61), welded to the side of the hammer (53) remote from the pole tip, against a ribbon to create a dot on a print-receiving medium. Because the release coil (51) terminates just short of the tip of the post (49), the intensity of the flux produced by the coil (51) at the interface between the post tip and the hammerhead (59) is high.

Long release coil hammer actuating mechanism

Bi-directional, constant velocity, carriage shuttling mechanisms particularly suitable for use in dot matrix line printers, are disclosed. The carriage shuttling mechanisms comprise a pair of identically sized bi-lobed, second order elliptical gears (41, 45) connected together in a 90.degree. phase relationship either directly or via a belt. One of the bi-lobed gears is rotated at a constant velocity and the other is eccentrically linked (47) to the carriage (11) to be bi-directionally shuttled at a constant velocity.

Bi-directional, constant velocity, carriage shuttling mechanisms

A dot printing mechanism for dot matrix line printers comprising a plurality of hammer modules (45) mounted on a carriage (43) that is shuttled back and forth along a print line is disclosed. Each module includes a plurality of cantilevered print hammers (47) formed of a resilient ferromagnetic material. Each of the print hammers includes an anvil (49) on one face of its cantilevered outer end, adapted to print a dot when the associated hammer is actuated. The modules (45) are mounted on opposite sides of the print line and positioned such that the hammers (47) of juxtaposed modules are interleaved and such that the anvils (49) all lie along the print line. Further, each hammer forms part of a magnetic circuit that includes a permanent magnet (51), a post (57) and ferromagnetic paths between the permanent magnet and post. The post supports a coil (59) and is positioned near the cantilevered end of the print hammer (47), on the side opposite of the anvil (49). In the absence of current through the coil ( 59), the print hammer (47) is attracted to the post by the magnetic field produced by the permanent magnet (51) and, thus, cocked. The cocked hammers (47) are selectively released to create dots by the selective energization the coils. The selective energization is such that the coils (59) produce a magnetic field that counteracts the magnetic post attraction force created by the permanent magnet (51).

Dot printing mechanism for dot matrix line printers

A print head for a serial dot matrix printer comprising a sandwich structure including a base plate, a segmented-ring magnet, a print hammer disc and face plate is disclosed. The segmented-ring magnet comprises a ring formed of a magnetic material having spaced apart, magnetized, regions (segments). The print hammer disc is formed of a magnetically permeable, resilient material and has a plurality of inwardly projecting arms (hammers), each of which is aligned with a magnetized segment. Mounted on the hammers are print blades, which are aligned with radial slots formed in the face plate. Each print blade includes a dot-printing tip that projects orthogonally outwardly from the blade, and lies in a central aperture in the face plate. Mounted on the base plate, in line with each hammer, is a post having a coil mounted thereon. When the coils are de-energized, the magnetic field formed at the tips of the posts is adequate to overcome the spring force of the related hammer, whereby the air gap therebetween is closed and the hammer is cocked. Energization of any coil by a pulse of appropriate polarity and magnitude cancels the magnetic pull created by the related magnetic segment and allows the related hammer to pull away from the related post. This action creates a dot as the released spring force causes the dot-printing tip of the related print blade to press a print-producing material (e.g., a ribbon) against a print receiving medium (e.g., a sheet of paper). Rather than defining a single column, the dot-printing tips define two or more columns.

Segmented-ring magnet print head

A half-herringbone support for the comb hammers of a dot matrix line printer is disclosed. The half-herringbone support is generally flat and includes an elongate base and a series of parallel tines integrally formed with said base and projecting obliquely outwardly from one edge of the base. The number of half-herringbone tines is equal to the number of hammers. The base of the half-herringbone support is affixed to the base of the hammer support on the side containing the hammer anvils (balls). The outer tips of the half-herringbone tines project to a point where they each intersect the mid-region of a related hammer. The tips of the half-herringbone tines are welded to the hammers at the points of intersection. The portion of said half-herringbone tines passing over hammers other than the hammer to which a particular half-herringbone tine is welded are undercut to prevent rubbing between the half-herringbone tines and the hammers over which the half-herringbone tines pass, but with which they are not associated.

Half-herringbone support for restricting sideways vibration of comb

A light collector and prism that collects light from a single bulb and produces a narrow strip light beam is disclosed. The light collector and prism is formed of an elongate, integral piece of transparent material (plastic) and includes a light collecting section at one end and a prism section at the other end. Light rays emitted from a small bulb positioned in an aperture in the light collecting section are collected, to some extent (e.g., imperfectly) collimated, and directed into the prism section. The prism section extends outwardly from the collector section so as to receive the light rays collected, collimated and directed by the collecting section. The prism section includes a plurality of prism surfaces located along one edge thereof. Light rays directed by the light collecting section toward the prism section are reflected by the prism surfaces toward an opposing, narrow, light emitting edge of the prism section. Light rays emitted from the narrow edge form a narrow strip light beam. Preferably, all of the surfaces of the light collector and prism are metalized, except for the aperture within which the light source is mounted and, the narrow edge of the prism through which the narrow strip light beam is emitted.

Growing community of inventors

Seattle, WA, United States of America

Edward D Bringhurst