Abstract: For the production of a printing stencil, a fine-mesh screen is provided with an unexposed photoemulsion layer and aligned in order to establish it in an essentially tubular or flat shape On the photoemulsion layer, those locations which are not to be exposed are covered with an opaque layer according to a particular pattern. The opaque coating layer--together with the non-exposed portions of the photoemulsion layer--is removed after the exposure of the non-covered locations of the latter. The opaque coating material contains wax and preferably is soluble in water. To avoid a perceptible starting line in the case of a tubular screen, the pattern start is varied according to any law, preferably following a sine line, in order to avoid a clear-cut separating line.

Abstract: The connector comprises a female element (12), a male element (14) and a body (16). The female element, made of conductive metal sheet or pipe, has a portion formed by fingers (21) having a certain degree of elasticity, which are normally spread apart when no external forces are applied. The fingers have retaining teeth (28) extending inwards. The male element has a shoulder surface (38) for engagement by the teeth of the female element. One element, male or female, holds the plug, and the other element, female or male, holds the socket. The body has a housing for the female element, comprising first and second communicating chambers, the first chamber housing the female element in a spread apart condition, and the second chamber housing the female element in a narrow, forced condition. Insertion of the male element with the shoulder surface thereof beyond the retaining teeth automatically locks the male element and the female element in a connected or wired position.

Abstract: The framework has at least one vertical support column (3), into which a telescopically height-adjustable foot (4) connected to the support column (3) is inserted. An approximate presetting and subsequently a fine height adjustment are possible by means of a height-adjustable adjusting member (15), which is self-supporting at the foot (4).

Abstract: Described is a particular procedure to make structures from longitudinal helical metal strips, the same are adecuate to conform different objects, such as plates, planks, sheets, tubes, shafts, etc. and they are porous, flexible, highly resistant and with great ability to absorb the different applications to which they may be subjected, i.e. mechanical, caloric, sound, etc. The procedure consists in stinging the entangled metal strips, each metal strip with its adyacent, until "layers" are formed, and these, in turn, are entangled to each other until a structure is formed, which gaps determining the porosity will be at least the same size than the thickness of the filament constituting the metal strip. The layers may be formed by metal strips made of any type of material (metallic, synthetic, etc.) and they may be combined among them.