Abstract: An adjustable-height chair column comprises an upright tube and a gas spring that is disposed coaxially in the upright tube. The gas spring comprises a valve for actuation of the gas spring. This valve is embodied for opening upon relief of the casing of the gas spring in relation to the upright tube.

Abstract: A compression spring comprises a casing in which a piston is arranged for displacement, the piston being mounted on a piston rod. In the casing provision is made for two sectional casing chambers which are filled with pressure fluid, at least one of which being defined by the piston. A first operating valve, in an open position, connects the sectional casing chambers to each other and, in a shut-off position, blocks the compression spring. An additional throttle element ensures that an actuation and over-flow assembly between the sectional casing chambers is completely open only when the throttle element, with the valve pin tripped, is simultaneously moved by corresponding actuation into a position of release. Without any such actuation of the throttle element, there will be only throttled flow between the sectional casing chambers. Any inadvertent extension of the piston rod is thus precluded. This is an especially convenient and intuitive way of backrest adjustment in a seat.

Abstract: A compression spring comprises a casing in which a piston is arranged for displacement, the piston being mounted on a piston rod. In the casing provision is made for two sectional casing chambers which are filled with pressure fluid, at least one of which being defined by the piston. A first operating valve, in an open position, connects the sectional casing chambers to each other and, in a shut-off position, blocks the compression spring. An additional throttle element ensures that an actuation and over-flow assembly between the sectional casing chambers is completely open only when the throttle element, with the valve pin tripped, is simultaneously moved by corresponding actuation into a position of release. Without any such actuation of the throttle element, there will be only throttled flow between the sectional casing chambers. Any inadvertent extension of the piston rod is thus precluded. This is an especially convenient and intuitive way of backrest adjustment in a seat.

Abstract: An adjustable length gas spring comprises a housing, in which a piston mounted on a piston rod is guided for displacement. The piston divides the housing into two partial volumes. Furthermore, a valve is provided for the interconnection of the partial volumes. A device is provided for closing the valve, by means of which the valve is closed when the partial volume which the piston rod does not pass through reaches a given minimum length.

Abstract: A guide bush for an adjustable length column for chairs, tables or the like is provided, in its inner portion, with a slide bush concentric of a central longitudinal axis for the guidance of a cylindrical housing of a gas spring. The outside wall of the slide bush is provided with spaced ribs for the reception and support, radial to the axis, in an upright tube of the column. The ribs are elastically deformable radially to the central longitudinal axis.

Abstract: A longitudinally adjustable gas spring for adjustable-height chairs, tables or the like has an external cylinder, in which a piston is guided for displacement, to which a piston rod is secured, which is guided out of the exterior cylinder. The exterior cylinder has a thin hard external nitrided layer and a considerably softer core layer enclosing the inside wall of the exterior cylinder.

Abstract: Described is a lifting device for cylindrical templates in printing machines, with an inking tube extending through each cylindrical template, the lifting device travelling along a rail running parallel to the direction of the cylindrical template and along a rail travelling in a direction normal thereto and which can be releasably connected to the inking tube. The lifting device is constructed in the form of a hydraulically or pneumatically operated telescopic arm, always in the vertical position, which carries a tong-like gripper (2) for releasable connection with the inking tube (3).

Abstract: Halogenated aromatic amines are rendered colorstable by distillation and/or storing in equipment made of a rustproof material such as a Cr/Ni/Mo steel, tin, zinc, enamel, glass and/or ceramic material.

Abstract: An improvement in a process for the preparation of chlorinated aromatic amines by hydrogenation of the corresponding chlorinated nitro-aromatic compounds in the presence of a noble metal catalyst on a carbon support and in the presence of a sulfur compound, the improvement residing in that the sulfur compound is a thio-ether. Preferably the reaction is carried out in a weakly basic medium.

Abstract: Diamino naphthalene having the formula ##STR1## wherein R.sup.1 is hydrogen or amino is prepared by treating dinitro naphthalene having the formula ##STR2## wherein R.sup.2 is hydrogen or nitro WITH HYDROGEN IN THE PRESENCE OF HYDROGENATION CATALYSTS AND ORGANIC SOLVENTS HAVING THE FORMULA ##STR3## wherein R.sup.3 is hydrogen, halogen or alkyl;R.sup.4 is hydrogen, halogen, alkyl, hydroxy, alkoxy, amino, alkylamino, or dialkyl amino;R.sup.5 is hydrogen, chlorine, alkyl, hydroxy, alkoxy, amino, alkylamino or dialkyl amino;R.sup.6 and R.sup.7 are the same or different and are either hydrogen or alkyl or together form a --(CH.sub.2).sub.4 group, optionally substituted once or several times by methyl and/ethyl.

Abstract: Aromatic diamines having the formula ##STR1## wherein R is alkyl or alkoxy having up to 6 carbon atoms are prepared by treating dinitro compounds having the formula ##STR2## wherein R is as previously defined, with hydrogen in the presence of one or more noble metals from the platinum or palladium groups as catalysts, optionally on catalyst supports, and in the presence of optionally substituted aniline as the solvent.The catalyst is generally used in amounts of 0.0005 to 0.1% by weight based on the amount of dinitro compound employed.

Abstract: The top edge portions of a ski of plastic material are produced in a two-part mold by placing the bottom surface sheet and edge portions of the ski on the floor of the mold while preformed top edge portions carry the top surface sheet and are supported in the mold by an auxiliary strip which extends outwardly from its side surface and rests on two opposite walls of the mold box. The auxiliary strips are held in place by magnets lodged in the opposite mold walls while the mold is open. After closing the mold with the mold lid a plastic foam material in the mold is expanded to produce the ski core and bond together the top and bottom surface sheets and edge portions of the ski. The auxiliary strips are severed from the top edge portions to finish the ski.