Abstract: A modified wire guide and assembly method for facilitating the insertion of wires into a dot matrix print head. In the preferred embodiment, the wire guide has a planar surface with downwardly extending wire holes defined by first and second surfaces. The first surface has a truncated conical shape and the second surface has a cylindrical shape. Additionally, the wire guide has an upwardly extending, inclined cam surface that intersects the planar surface to form a closed path. The first surface defining each hole is positioned adjacent the cam surface and intersects the closed path so that a wire striking the cam surface will move down it toward and into one of the holes. The assembly method of the present invention involves inserting a wire through three wire guides using aids that apply a first force in a first direction to bow the wire and then apply a second force in an opposite direction to guide the wire through the print head.

Abstract: This invention involves methods and apparatus relating to the assembly and structure of a dot matrix print head. In the preferred embodiment, the tops of the bobbins, yoke members, and pole pieces are ground flush in a common plane. The common plane is then used as a reference to mount and assembly remaining elements of the print head including the clapper members and backstop for the clapper members. The clapper members are mounted for pivotal movement between first and second positions by a cover member and securing cap. For uniform operation, the pivotal axis are all in the common reference plane on respective bobbin members and the gaps of the clapper members are automatically set to the identical size by intermeshing fingers on the cover and cap members. Additionally, corresponding and abutting surfaces on the bobbins, cover member, and cap member act in concert by the operation of a single screw to properly align, assembly, and adjust the operating parts of the print head.

Abstract: This invention involves methods and apparatus relating to the assembly and structure of a dot matrix print head. The invention includes a single unit, coil assembly of a bobbin, coil, and clapper which can be removeably placed as a unit among fixed pole pieces and yoke members in the print head. The print head also includes a supporting arrangement for the coil assemblies which automatically aligns the clapper of each coil assembly with the impact end of one of the print wires during the assembly of the print head. Other disclosed features of the invention are novel designs for the wire guide members, a heat sink member, and mounting structure by which the print head is attached to the main guide and rail guide bearings of the printing mechanism.

Abstract: A bearing for a rotating shaft including a main body with three sections. The first section has a square profile whose sides are dimensioned to be received in a corresponding square slot in a support structure and held against rotation. The second section has a profile with at least five sides with four sides thereof being coplanar with the four sides of the first section. The fifth side falls within the profile of the first section and preferably is substantially the same thickness as the support structure plus a retaining clip. The third section has a profile with a portion greater than any portion of the profiles of the first and second sections wherein the bearing can be inserted into the slot in the support structure and held in place with a retaining clip positioned substantially about the second section.

Abstract: A transport system for a dot matrix printing mechanism including an improved overall design for the transport system and improved designs for individual elements of the system and combinations of elements. The overall design of the present invention uses snap fits extensively throughout for ease of assembly and disassembly, integrates many previously separate parts into one-piece members, employs common part designs wherever possible, and uses single parts to perform multiple functions wherever possible. For example, the striker bar and ribbon frame of the system are combined into one piece and the ribbon cartridge is releasably mounted to the ribbon frame using one end of a latch member while the other end of the latch member is used to bias a pressure roller against the paper advancing roller. The overall design also includes a common drive train interconnected between the moving parts of the system whereby all of the moving parts can be powered by a single motor.

Abstract: This invention involves methods and apparatus relating to the assembly and structure of a dot matrix print head. The invention includes a single unit, coil assembly of a bobbin, coil, and clapper which can be removeably placed as a unit among fixed pole pieces and yoke members in the print head. The print head also includes a supporting arragement for the coil assemblies which automatically aligns the clapper of each coil assembly with the impact end of one of the print wires during the assembly of the print head. Other disclosed features of the invention are novel designs for the wire guide members, a heat sink member, and mounting structure by which the print head is attached to the main guide and rail guide bearings of the printing mechanism.

Abstract: This invention involves methods and apparatus relating to the assembly and structure of a dot matrix print head. The invention includes a single unit, coil assembly of a bobbin, coil, and clapper which can be removeably placed as a unit among fixed pole pieces and yoke members in the print head. The print head also includes a supporting arrangement for the coil assemblies which automatically aligns the clapper of each coil assembly with the impact end of one of the print wires during the assembly of the print head. Other disclosed features of the invention are novel designs for the wire guide members, a heat sink member, and mounting structure by which the print head is attached to the main guide and rail guide bearings of the printing mechanism.

Abstract: This invention involves methods and apparatus relating to the assembly and structure of a dot matrix print head. The invention includes a single unit, coil assembly of a bobbin, coil, and clapper which can be removeably placed as a unit among fixed pole pieces and yoke members in the print head. The print head also includes a supporting arrangement for the coil assemblies which automatically aligns the clapper of each coil assembly with the impact end of one of the print wires during the assembly of the print head. Other disclosed features of the invention are novel designs for the wire guide members, a heat sink member, and mounting structure by which the print head is attached to the main guide and rail guide bearings of the printing mechanism.

Abstract: This invention involves methods and apparatus relating to the assembly and structure of a dot matrix print head. The invention includes a single unit, coil assembly of a bobbin, coil, and clapper which can be removeably placed as a unit among fixed pole pieces and yoke members in the print head. The print head also includes a supporting arrangement for the coil assemblies which automatically aligns the clapper of each coil assembly with the impact end of one of the print wires during the assembly of the print head. Other disclosed features of the invention are novel designs for the wire guide members, a heat sink member, and mounting structure by which the print head is attached to the main guide and rail guide bearings of the printing mechanism.

Abstract: A transport system for a dot matrix printing mechanism including an improved overall design for the transport system and improved designs for individual elements of the system and combinations of elements. The overall design of the present invention uses snap fits extensively throughout for ease of assembly and disassembly, integrates many previously separate parts into one-piece members, employs common part designs wherever possible, and uses single parts to perform multiple functions wherever possible. For examples, the strike bar and ribbon frame of the present invention are combined into one piece and the ribbon cartridge is releasably mounted to the ribbon frame using one end of a latch member while the other end of the latch member is used to bias a pressure roller against the paper advancing roller. The overall design also includes a common drive train interconnected between the moving parts of the transport system whereby all of the moving parts can be powered by a single motor.

Abstract: A lightweight, extremely compact printer apparatus has a constant speed drive which imparts reversible, translatory motion to a print head; and as the print head is advanced with respect to a platen imparts a direct mechanical drive to a paper advancing roller in order to advance paper from a feed roll line by line between printing operations. In turn, advancement of the paper or other recording medium from the paper roll drives a print ribbon supply holder to advance a print ribbon across the platen in front of the paper. The power requirements and size of the apparatus are substantially reduced to the extent that the apparatus is of a size corresponding to hand held calculator printers, since the movement of each element is utilized to drive another element successively from the print head carrier, paper advancement roller, paper roll to the print ribbon in close correlation to one another during each print cycle.