Abstract: A focal plane shutter apparatus having two single flexible shutter blades for respectively uncovering and then covering an exposure aperture to make an exposure are incorporated into a 35 mm camera. Each shutter blade has a driven end and an opposite free end with both free ends sliding in the same guide channels across the exposure aperture. Each of the shutter blades has its driven end retained by a special rotary structure. Each rotary structure is acted upon by an adjustable acceleration spring and by a weak carry-through spring. Each shutter blade and its respective rotary driving structure are smoothly and quietly stopped by respective pairs of rocking cams which coact during shutter blade overtravel. The rocking cam structures used for stopping may be reset by another respective pair of rocking cams which coact during almost all of a shutter rewind sequence.

Abstract: An improved impulse-operated rotary stepping motor is constructed with a two-part stator assembly and coil support for each stage to reduce manufacturing costs, improve the magnetic characteristics, improve alignment of the rotor of each stage, provide for an integral bearing, make practical the construction of a motor having the rotor teeth on the inside of the rotor armature shell, and to improve and sharpen the detenting action when stopped by bilaterally stepping the top width of the rotor and stator teeth at least once along the length of each tooth.

Abstract: A paper feeding and guiding system for a printer with a flat platen has twin mating feed rollers fitted with "O" ring type friction elements cooperating with specially curved entrance and exit paper directing and guiding members which keep the paper or other record material flat against the platen face without the use of a bail or vacuum system. The axis of one feed roller is adjustable to alter the rolling radius of the "O" rings from one end of the feed rollers to the other to provide correction for skew feeding of the record material. The exit paper guide is vibration isolated from the platen bar and fitted with a noise control flap to close off the paper entrance cavity. The mechanism for disengaging the feed rollers for paper insertion is combined with a paper alignment guide which is projected into the path of the inserted paper to align the top edge for correct feeding and coincidence with the steps of a stepping motor drive which incrementally drives the feed rollers.

Abstract: A frame-supported disposable ribbon supply and take-up cartridge for typewriters and printers of the type employing a carriage-transported printing device is equipped with a constant path length ribbon guiding and directing structure which can be collapsed and folded for compact packaging and which can also be factory pre-threaded to eliminate any need for the operator to fit a ribbon leader around any guides on the print carriage. One form of the invention uses twin one-way articulated ribbon guides which are connected by a ribbon directing bar and are each orthogonally pivoted to the sides of the cartridge for collapsing, rotating, and folding against the sides of the cartridge. The other form uses a single two-way articulated ribbon-guiding structure pivoted to the cartridge and having a second articulated structure, all of which can be folded against the sides of the cartridge.

Abstract: A keyboard input device for printers, composing apparatus, or clear text display devices which employ type fonts that can be changed at will, has a group of multiple indicia bearing keys which can be positioned to bring a different set of indicia to a readable position to indicate to the operator the character make-up of the type font being used. Both manual and electrical mechanisms are provided to effect indicia positioning. Mechanism is also provided to interconnect indicia selection with either manual or automatic type font selection and changing. Each key operates an electrical switch which is connected to a diode matrix to provide coded output to the device under control.

Abstract: A printer employing a movable print carriage is fitted with a single rigid bar-like carriage support structure having three very narrow, low friction, plain guideways, either grooves or rails, kinematically arranged for extremely accurate guiding of the printing carriage as it moves along the writing line. The print carriage is fitted with kinematically arranged mechanically reciprocal guides for engaging the guideway grooves or rails. The carriage support structure is made sufficiently rigid and massive to also serve as the printer frame for supporting the platen and other printer parts and elements. The location of the three guideways, primary feed roller bearing supports, platen supports, and platen adjustment rod bearings are such that all can be machined in one set-up in a multiple spindle machine tool so as to achieve exact parallelism of all the elements requiring precise alignment.

Abstract: A printer is fitted with a squeeze printing mechanism employing a toggle or over-the-center crank mechanism to provide direct pressure to a printing element for accurate impression depth control during imprinting and for achieving low velocity at the time of print element contact with the paper to materially reduce printing noise. Mechanism and linkages are provided for either single or double electromagnetic actuators. The linkages are arranged to provide rectilinear movement of the type face bearing element just prior to and during imprinting. Over pressure relief is provided for the toggle or over-the-center crank mechanism to prevent damage or lock-up if the printer platen position is not correctly adjusted for the paper being used.

Abstract: A compliant structure formed of resilient tape of the self-straightening type is used to guide a web of thin material which is transferred between two machine elements that have relative motion to each other. The structure is applied to a ribbon supply and take-up system for typewriters and teleprinters of the type having a carriage-transported printing device. The resilient tape, with one surface being used to guide the ribbon, is connected and constrained between a frame-supported ribbon supply and take-up assembly and the printing device carriage to form a loop-like structure for guiding and generally supporting the ribbon along a path of constant length regardless of carriage position. The compliant ribbon-guiding structure is also incorporated into an easily installable ribbon carriage.

Abstract: A frame-supported ribbon supply and take-up system for typewriters and teleprinters of the type having a carriage-transported printing device. The system incorporates an articulated ribbon-guiding structure connected between the ribbon supply and take-up assembly for guiding and supporting the ribbon along a path of substantially constant length regardless of carriage position. The articulated structure is also incorporated into an easily installable ribbon cartridge.

Abstract: A frame-supported ribbon supply and take-up system for typewriters and teleprinters of the type having a carriage-transported printing device. The system incorporates an articulated ribbon-guiding structure connected between the ribbon supply and take-up assembly for guiding and supporting the ribbon along a path of substantially constant length regardless of carriage position. The articulated structure is also incorporated into an easily installable ribbon cartridge.