Abstract: A manipulator having an end effector (1) displaceable by means of a four-rod mechanism, a comparatively light and stiff construction being obtained in that each of the rods (3,5,9,11) has a tubular support (73,79,159,181), which is secured by a bridge (147,149,169,191) to the bearing plate (87,93,119,193). The manipulator is particularly suitable for use in automatic mounting equipment.

Abstract: The invention relates to a color display tube having a color selection electrode which is suspended in the tube by engagement of apertured elements connected to flat resilient elements extending from the corners of the electrode, with the spherical heads of pins extending from the corners of the display window. According to the invention, a rigid construction is obtained by providing apertures shaped so that each spherical part has at least three points of engagement with its respective apertured element, and at least one point of engagement is outside the plane of the flat resilient element.

Abstract: The invention relates to a method and apparatus for pressforming an article of a thermoplastic material. In accordance with the method a charge of molten material is deposited in a mould (14) and the central axis of a pressing plunger (18) and the mould (14) are aligned, after high a pressing operation is performed, the alignment being interrupted just before the end of the pressing operation. The apparatus comprises a frame (2), a mould (14) and a plunger (18), which plunger (18) is connected to a guide mechanism (22) which is movably connected to the frame (2) and which can be coupled rigidly to the mould (14) by coupling means (52).

Abstract: An optical telecommunication element comprising one or more undulating optical fibers in which each fiber extends along a sheath. Each fiber is in the form of a helix or quasihelix which has an alternating left-handed and right-handed pitch. The fibers are fixed on the inner wall of the sheath at points of pitch reversal, the fibers preferably being fixed by glued joints.

Abstract: An optical telecommunication element which is constructed from a central optical fiber which is under an axial pressure and which is incorporated in a close-fitting sheath of supporting fibers having a modulus of elasticity which is at least 4000 kg/mm.sup.2. The optical fiber is fixed within the sheath by a layer of cured lacquer.

Abstract: An optical fiber cable comprising a cylindrical body and optical fibers which are located, and periodically fixed, in respective grooves in the body. The grooves extend along the length of the body in a helical manner, which may periodically change its sense of rotation. The grooves are either in the surface of the body or in the inner surface of a jacket surrounding the body. The fibers may be fixed after every full turn by means of a wire located in a longitudinal groove which crosses the grooves in which the fibers are fixed. The fibers may alternatively be periodically fixed by means of a longitudinally extending adhesive strip. The whole assembly may be provided with a layer of wound tape and a jacket.

Abstract: An arrangement for centering, aligning and retaining a rigid disc such as a rapidly rotating video disc in an operating position, comprising a centering device mounted on a drive spindle, which device cooperates with a central disc hole in the disc, comprising a disc aligner mounted on the drive spindle for aligning the disc in a plane perpendicular to the axis of rotation of the drive spindle in the operating position of said disc, and comprising a disc loader for loading the disc towards the disc aligner. The disc aligner is rigidly connected to the drive spindle and the centering device comprises a plurality of resilient centering members which cooperate with the wall of the disc hole and which are radially movable between a rest position and an operating position which is situated nearer the axis of rotation of the drive spindle.

Abstract: A device for recording measuring values on a record carrier by means of two approximately parallel, linear motors which are pivotably connected to two arms which are both connected to a single recording head. A signal generator produces signals which indicate the position of the recording head and a control device controls the motors so that the recording head is moved, without a mechanical guide, along a straight line which is perpendicular to the transport direction of the record carrier.