Abstract: Surgical procedures on biological tissue are carried out with the aid of a laser with substances being applied to the tissue before or during the treatment and these substances are absorbent in the range of the wavelength of the laser beam. A surgical manipulator can be provided and equipped with suction and irrigation channels and the substances can be directed to one of these channels via a metering unit. The application of substances such as sulfisomidine or sulfacetamide increases the ablation rate and reduces the threshold of the ablation process. At the same time, sensitive structures are protected from the damaging effects of the laser radiation as well as from the stray radiation and fluorescence radiation triggered by the laser radiation during the application of microsurgery to the eye.

Abstract: A method for operating an automatic control system for injecting fuel into an internal combustion engine, with the control system having an error correcting capability for deviations that occur in the control signal being processed by the control system, and with the control system having a controlling element, which is embodied as a precontrol, and PI-controller that are operated in parallel.

Abstract: The invention relates to a bearing ball (10, 11) for receiving the implement pin (8, 9) of an agricultural implement (1) in the catching jaw (7) of the catching hook (6) of a three-point connecting device (3) belonging to a tractor (2). The bearing ball comprises a hollow ball (2) with a cylindrical tube (14) passing through it. The central region of the cylindrical tube (14) has been provided with a formation (15) which extends radically and supports the inner face (13) of the hollow ball (12) in a force-free way. It secures the hollow ball (12) on the cylindrical tube (14) in the axial direction and permits relative rotation between the two. This provides better support because only the ends of the cylindrical tube (14) rest against the implement pin and bending of the cylindrical tube (14) no longer adversely affects the bearing ball.

Abstract: In an armoured vehicle with a turret, a weapon mounted therein and a magazine housed in the armoured vehicle and receiving large calibre ammunition in the upright position in a concentric arrangement with respect to the turret rotation axis is arranged a loader, which has a loading arm gripping the ammunition on the magazine and raising it into an aligned position with the weapon bore axis, i.e. the loading position. The loader is arranged on a ring mount positioned roughly below the weapon breech block on the turret platform and whose rotation axis coincides with that of the turret and has a multilever guide supported on the ring mount and movable in a vertical plane, which raises the loading arm with the upright ammunition in a steep movement path and only towards the end of the movement path swings into the loading position.

Abstract: The invention relates to electric insulation with a polyolefin base for medium and high voltage from about 10 kV up. In insulation of this type the formation of so-called water trees is to be prevented on the one hand and on the other hand, the dielectric losses are to be kept as low as possible. For this purpose it is provided that silicic acid prepared in the following manner is added to the insulation: SiO.sub.2 -containing mineral substances are melted with additions of aluminum oxide, boron oxide and carbonates and/or oxides of alkali and earth-alkali metals to form a homogeneous glass phase; from the glass melt, glass bodies with a large surface are made; the glass bodies are subjected to a leaching process with mineral acid; the porous SiO.sub.2 bodies produced are washed and dried and optionally milled. The electric insulation according to the invention is particularly well suited for use in cables and wires.

Abstract: An interchangeable conveying spiral which can be removably, slidably mounted on a drill shaft for conveying drillings away from a drill head mounted on the end of the spiral. The spiral includes an elongated strip having at least first and second substantially orthogonal webs. The first web has a free, squared-off end. The strip is wound in a spiral with the free, squared-off end of one turn abuting the free, squared-off end of an adjoining turn of the spiral so that the first web forms a closed jacket tube which can be removably, slidably mounted on a drill shaft, and the second web serves exclusively as a transporting shoulder for conveying drillings.

Abstract: The invention relates to an electrical insulation composition of a polyolefin, which can be used for medium and high voltage from about 10 kV and which resists effectively and permanently the formation of so-called water trees. The insulative polyolefin contains an inorganic oxide additive, in homogeneous distribution therewith, at a concentration of 0.05 to 10% by weight, relative to the total weight of the composition. The additive is absorption-active for heavy metal ions and/or binds heavy metal ions in an ion exchange, with a particle size of up to 50 um or an agglomerate size of up to 100 um. It can be silica, alumina, hydrated alumina or an aluminum silicate. The electrical insulation according to the invention is particularly well-suited for use in cables and wires.

Abstract: The electrode pins for an arc furnace are individually and separately mounted in the bottom of the furnace vessel in that the refractory lining of the vessel is provided with apertures receiving individual refractory perforated bricks traversed individually by an electrode pin, the electrode pin is secured in an insulated fashion to the metal jacket of the vessel and traverses the perforations of the bricks, moreover the pin is connected through appropriate clamping facilities to the cooled anode current feed mounted insulatedly underneath the bottom of the vessel.

Abstract: A boring tool for producing undercuts in preformed holes. The boring tool has a cutting element which is provided at one end of a driving shaft. In order to produce the undercut, the driving shaft can be deflected at right angles to the axis thereof via a deflection mechanism. The deflection mechanism is accommodated in the boring tool, and is provided with a longitudinally displaceable deflection rod for positively deflecting the driving shaft. In the deflected position, the driving shaft is driven by a rotary drive which is separate from the turning drive. As a result, the undercuts can be very precisely produced.

Abstract: The invention relates to electrical insulation material of a polyolefin composition with a phosphate additive which prevents the formation of so-called water trees. The phosphate additive may be a water-soluble alkali or earth-alkali phosphate and/or a hydrolysable phosphoric acid ester (RO).sub.3 PO, wherein at least one of the substituents R is an aliphatic radical and the remaining substituents may be hydrogen or an aliphatic radical. The electrical insulation according to the invention is suited particularly for use in cables and wires.

Abstract: The invention relates to electric insulation of polyolefin suitable for medium and high voltage from about 10 kV which resists the formation of so-called water trees. For this purpose, the insulation contains as an additive at least one alcoholate of magnesium, calcium or aluminum. The electric insulation according to the invention is particularly suitable for use in cables and wires.

Abstract: A valve is disclosed for gaseous and/or liquid flow media, in particular a pressure control valve for an exhaust recirculation valve in injection systems in motor vehicles. For the sake of attaining an extremely small opening hysteresis, this valve has a leakage point which is effective between the contact faces of the valve closing member and the valve seat. The suction flow brought about by the leakage point generates a film of flow medium between the contact faces which prevents the complete closure of the valve at a static point on the characteristic valve curve.

Abstract: The invention relates to electrical insulation material of a polyolefin composition containing an additive which prevents the formation of so-called water trees. Barbituric acid compounds are the additives and include barbituric acid, 2-thiobarbituric acid or substituted barbituric or thiobarbituric acid derivatives. The electrical insulation according to the invention is suited particularly for use in cables and wires.

Abstract: A boring tool for radial widening or enlargement of a cylindrical bottom, foundation, or anchor bore. The boring tool comprises a tubular tool body having a tool shank provided for clamping in a driving machine or prime mover, and an enlarging spindle guided in the tool body and adapted to be supported on the bottom of the bore. When entering into the tool body, the enlarging spindle radially adjusts the cutting parts or elements provided for carrying out the enlargement. The tool body is formed of radially resilient segments which extend in the axial direction and delimit longitudinal slots which are open toward the front end of the tool. Cutting parts or elements are arranged on the free ends of the segments, with each part having an axial working which extends in the circumferential direction of the tool body, with those working surfaces which are adjacent one another in the circumferential direction forming the front end face of the tool body.

Abstract: A coupling hook assembly having a hook body defining an enclosed hook pocket with a locking bolt extending from a first aperture in the hook body into operative engagement with a hook jaw to lock and unlock an implement pin for joining a trailer with an agricultural tractor. The locking bolt is pivotally connected with an operating lever mounted on a fixed pivot within the hook body and extending through a second aperture therein. A yoke pivotally mounted on the operating lever is adapted to engage with a notch formed on the external surface of the hook body to secure the locking bolt in the locked position or into engagement with a recess in a part of the operating lever to secure the coupling hook assembly in the unlocked position.

Abstract: A steering column switch assembly includes a carrier housing mounted on a steering column adjacent a steering wheel thereon. A plurality of switches, each in a housing, is detachably mounted in the carrier housing between a respective one of a plurality of pairs of parallel carrier faces on the carrier housing and extending parallel to the axis of the steering column. Resilient means on each switch housing engage stop surfaces on the respective pair of carrier surfaces to retain said switch housing in said carrier housing.

Abstract: A three-point tractor hitch system includes a coupling hook structure as the upper link thereof formed with a hook body defining a concave recess for receiving therein in locking engagement a coupling sphere. A locking bolt received within a rectilinear opening extends into the concave recess of the hook body with a curved locking surface adapted to engage the contour of the coupling sphere. The locking bolt is pivotally mounted at its opposite end to a control lever having a generally U-shaped recess formed therein to engage a bearing pin mounted on the hook body. The U-shaped recess has lateral sides arranged so that imaginary extensions thereof will intersect the axis of the locking bolt and bearing means are interposed between the control lever and the hook body on a side of the pivotal coupling of the locking bolt to the hook body opposite the side on which the U-shaped recess is formed.