Abstract: A mechanical pencil unit of the pushbutton-action type and a ballpoint pen unit are housed in a common holder having top and bottom sections which are rotatable in oppposite directions relative to each other. Mounted within the holder and substantially secured to its bottom section only is a cradle which supports and constrains the two writing units for independent longitudinal motion with respect to the holder. The writing units are spring-biased into sliding engagement with an overhanging, downward-facing cam ledge on the inside surface of the holder top section, such that the writing units are selectively moved from a retracted to a writing position upon manual rotation of the holder top section in either direction relative to its bottom section. Upon movement of the mechanical pencil unit to the writing position, an offset pusher finger extending downwardly from a pushbutton on the holder is moved into alignment with the pencil unit for actuating and making the same ready for writing or marking.

Abstract: A dot printing wire is provided at its tip with a wear-resistant contact made of an alloy selected from the group consisting of alloys composed of two or more platinum group metals, alloys of platinum group metals and transition metals and alloys of platinum group metals, transition metals and boron.

Abstract: A writing unit locking mechanism in a writing implement having a mechanical pencil unit and a ball point pen unit both housed in a single holder cylinder. The locking mechanism has a writing unit selection member having a shift member shiftable under gravitational force to select one or the other writing unit and operated manually to actuate a chuck in the pencil unit and a catch shoulder provided on a unit cylinder of the pencil unit and adapted to engage directly with the holder cylinder or with an engagement member resiliently supported on the holder cylinder thereby to lock the pencil unit in its writing position. The pencil unit is released from its locked state simultaneously with the release of the selection member.

Abstract: A display device is disclosed which employs a magnetic panel. The magnetic panel is formed by two oppositely arranged substrates at least one of which is transparent or semi-transparent. The space between the two substrates is filled with a dispersing liquid having a yielding value higher than 5 dyne/cm.sup.2. The dispersing liquid is prepared with fine magnetic grains, a coloring agent, a dispersing medium, and a fine grain thickener. Preferably, a multi-cell structure is provided in the space between the two substrates and the substrates are sealed to the multi-cell structure to form a plurality of independent display cells. A displaying magnet in the form of a pen is used to form a display by causing the fine magnetic grains to migrate to the front of the magnetic panel. An erasing magnet is slidably disposed at the rear of the magnetic panel.

Abstract: A dry writing board possessing an anti-halation effect which comprises a metallic plate having a ground coat fire-coated with a glaze comprising an acid component and a base component, the composition of the glaze being 30 to 45% of silicon oxide, 15 to 25% of titanium oxide, 5 to 10% of sodium oxide, 5 to 15% of potassium oxide, 1 to 5% of calcium oxide, 2 to 5% of aluminum oxide and 10 to 20% of boron trioxide, all percentages being by weight.

Abstract: A process for electrolytically treating aluminum or its alloys in the form of a strip, wire or foil material in a continuous manner which comprises continuously passing the material through an anodic oxidation treatment cell through which a direct current, alternating current or AC-superimposed direct current is caused to flow and an electrolytic coloring cell through which an alternating current or AC-superimposed direct current is caused to flow and carrying out electrolysis in both said cells to anodize and color the material in a continuous manner.

Abstract: A continuous electrolytic treatment apparatus for anodic oxidation and electrolytic coloring operations on an object such as a strip, wire or foil of aluminum and its alloys, wherein there are provided electric field buffer means which comprises a plurality of self-standing plates of plastic resin or the like having an electrically insulating property. The electric field buffer means are located at least in one zone in the electrolytic cell so that it can serves to effectively buffer concentration of excessive electric current to the interface between the object and the electrolytic solution at the above mentioned zone, thereby preventing burning in the surface of the object or in the oxide film formed thereon during the anodic oxidation treatment and unevenness in coloring of the object during the electrolytic coloring operation due to such current concentration, particularly when treating with a high current density.

Abstract: A writing material in solid form containing a solid vehicle in which is dispersed a non-volatile oily solvent containing electron a substantially colorless donative chromogenic compound which develops color upon contact with an electron accepting substance, more than 50 % by weight of the solid vehicle being an ester of a higher (hydroxy) fatty acid or a mixture comprising an ester of a higher (hydroxy) fatty acid and a microcrystalline wax, and the non-volatile oily solvent being contained in the writing material in a range of from 10 to 50 % by weight of the entire writing material.