Abstract: The cutting torch according to the invention is provided with an electric internal ignition device (3) and comprises a high-voltage source (19) arranged inside the cutting torch. The high-voltage source (19) contains a high-voltage transformer (4) with a rod-shaped ferrite core and an electronic controller (5) comprising a Meissner oscillator (20).

Abstract: A thermal working tool (1) is movable along a workpiece surface (7) and includes a torch head (2) which has exchangeably mounted thereon cutting or welding tools (3; 4; 5) extending between the torch head (2) and the workpiece surface (7). A distance control for setting a predetermined working distance (A) between the working tool (1) and the workpiece surface (7) is carried out by a magnetic system, an alternating magnetic field being produced in a sensor body with ferromagnetic properties above the workpiece surface (7). The torch head (2) and at least one of the cutting or welding tools (3; 4; 5) contain ferromagnetic material and form at least part of the sensor body (2; 3; 4; 5). The magnetic field produced is sensed by two measuring coils, and is used for controlling the working distance (A).

Abstract: In a known thermal working machine for working a workpiece, a thermal working tool (1) is provided that is movable along the workpiece surface (7) and comprises a torch head (2) which has exchangeably mounted thereon cutting or welding tools (3; 4; 5) extending between the torch head (2) and the workpiece surface (7). A distance control for setting a predetermined working distance (A) between the working tool (1) and the workpiece surface (7) is carried out by means of a magnetic system, an alternating magnetic field being produced in a sensor body with ferromagnetic properties above the workpiece surface (7). Starting from this, in order to permit a local measurement of even large working distances, the invention suggests that the torch head (2) and at least one of the cutting or welding tools (3; 4; 5) should contain ferromagnetic material and form at least part of the sensor body (2; 3; 4; 5).

Abstract: The invention relates to a photocurable, negative-working mixture and a recording material which is obtained therefrom and which is suitable for the production of elastic relief printing plates. The mixture contains a) an amphiphilic elastomeric binder, b) a free-radical-polymerizable compound which is compatible with the binder and which has at least one terminal, ethylenically unsaturated group and a boiling point of over about 100.degree. C. at normal pressure and c) a compound or a combination of compounds which is capable of initiating the polymerization of the compound b) on exposure to actinic light. The binder is made up of the segments A, B, C and X, where:A) is a hydrophobic soft block having a glass transition temperature T.sub.g of below about -30.degree. C.;B) is a hydrophilic hard block which contains basic groups and has a glass transition temperature T.sub.g of over about +10.degree. C.;C) is a hydrophobic hard block having a glass transition temperature T.sub.g of over about +50.degree. C.

Abstract: A graft copolymer of recurring units of (C.sub.6 -C.sub.18)alkyl (meth)acrylate (A), N-vinylpyrrolidone (B), glycidyl (meth)acrylate (C), and glycidyl (meth)acrylate units esterified with (meth)acrylic acid (D) onto which polymeric side chains of units of N-vinylpyrrolidone, (C.sub.1 -C.sub.3)alkyl acrylate and, if appropriate, (C.sub.1 -C.sub.3)alkyl methacrylate are grafted. The polymer is suitable as a binder for colorless, negatively chargeable liquid toners, in particular in combination with graft copolymers of (C.sub.1 -C.sub.6)alkyl (meth)acrylate, (C.sub.6 -C.sub.18)alkyl (meth)acrylate and units in which chains of N-vinyl-pyrrolidone units are grafted onto one of the units mentioned, as a charge control agent. After fixing of the electrophotographically produced toner image, the toners give colorless resist masks or printing screens with a high resistance toward etching agents and solvents.

Abstract: A graft copolymer of recurring units of (C.sub.6 -C.sub.18)alkyl (meth)acrylate (A), vinylpyridine (B), glycidyl (meth) acrylate (C), and glycidyl (meth) acrylate units esterified with (meth)acrylic acid (D) onto which polymeric side chains of units of vinylpyridine, (C.sub.1 -C.sub.3)alkyl acrylate, and optionally (C.sub.1 -C.sub.3)alkyl methacrylate are grafted. The polymer is suitable as a binder for colorless, positively chargeable liquid toners, in particular in combination with a copolymer of (C.sub.6 -C.sub.18)alkyl (meth) acrylate and hydroxyalkyl (meth)acrylate as charge control agents. After fixing of the electrophotographically produced toner image, the toners give colorless resist masks or printing screens with a high resistance toward etching agents and solvents.

Abstract: A process for the production of a colored image by an electrophotographic route by electrostatic charging, imagewise exposure to light and toning of a photoconductor material with a colorless transparent toner which includes a colorless polymeric binder and a colorless polymeric charge control agent, and transfer of the toner image to a colored layer which is soluble in a solvent and is on a layer carrier, fixing of the toner image and removal of the areas of the colored layer not covered by the toner image by washing out with a solvent. The process utilizes the high photosensitivity of electrophotographic materials, without the possibility of color falsification due to colored toners. The procedure is simpler compared with known electrophotographic processes, since the same toner can be employed in all steps and does not have to be washed off.

Abstract: A continuous process for the manufacture of photopolymer plates having a precise and constant thickness in which the components of the photopolymer layer are melted in a screw extruder, the melt is conveyed to the sheet die by means of a gear pump and then into a roll gap of a calender, wherein the melt leaving the sheet die does not form a rotating bead in the calender gap downstream therefrom. The photopolymer plates prepared in this manner have high homogeneity of the components of the photopolymerizable mixture, have a highly precise and constant thickness, are transparent, do not tend to form specks and guarantee a long shelf life.

Abstract: This invention relates to a photopolymerizable copying composition comprising at least one binder, at least one photoinitiator, and at least one polymerizable, acid amide group-containing acrylic acid derivative or alkyl acrylic acid derivative which is not volatile at 100.degree. C and contains at least two polymerizable groups in the molecule, the polymerizable compound containing at least one compound of the following general formulaA(--X--NH--CO--G).sub.pwherein:A stands for Z(--CO--NH--).sub.2 wherein Z is ##STR1## --O--CH.sub.2 --C.sub.q H.sub.2q --O--, or --O--(CH.sub.2 CH.sub.2 --O--).sub.rWhereinq is a whole number from 1 to 11, andr is a whole number from 1 to 5, or forE--C(--CH.sub.2 --O--CO--NH--).sub.3whereinE is CH.sub.3 --, C.sub.2 H.sub.5 -- or --NH--CO--O--CH.sub.2 --,G stands for ##STR2## or ##STR3## whereinn is 0, 1, or 2,m is a whole number from 1 to 11,k is 0 or a whole number from 1 to 4,R.sub.1 is alkyl with 1 to 3 carbon atoms, or --R.sub.4 or --CH.sub.2 --R.sub.4,R.sub.2 and R.sub.

Abstract: The invention relates to a photopolymerizable copying composition comprising at least one polymerizable compound, at least one photo-initiator, and at least one copolymer of (A) an unsaturated carboxylic acid, (B) an alkyl methacrylate with at least 4 carbon atoms in the alkyl group, and (C) at least one additional monomer which is capable of copolymerization with monomers (A) and (B), the homopolymer of said additional monomer having a glass transition temperature of at least 80.degree.C.