Abstract: A compact tripod includes at least three legs converging on a spider and hinged thereto at one end by a corresponding hinge sleeve and fork member. A support is provided for a head mounted on the spider in a position such that it projects from the spider opposite the legs when the tripod is open in an operating position. The hinge sleeve and fork member are designed to allow the legs to be folded back from the part of the support when the tripod is closed in a non-operating position. Additionally, the hinge sleeve and fork member include a toothed element and a corresponding stop for the toothed element which are capable of interacting together to limit the extent by which the legs open with respect to the spider.

Abstract: Auto body roof comprising at least one steel part and a skin part made of an aluminum alloy that is attached to the steel part before painting. The aluminum part comprises a sheet of the following composition: Si: 0.7-1.3, Fe<0.5, Cu: 0.5-1.1, Mn: 0.4-1.0, Mg: 0.6-1.2, Zn<0.7, Cr<0.25, Zr+Ti<0.20, other elements <0.05 each and <0.15 total, and the remainder aluminium. The aluminum part, after solution treatment, quenching and age-hardening for three weeks at room temperature, possesses a yield strength R0.2 of less than 170 MPa, and preferably 160 MPa.

Abstract: A tripod (1) for the support of apparatus in general and, in particular, of optical or photographic apparatus and the like is described and comprises a spider (3) in which a plurality of legs (2) converge and a pillar (12) arranged to receive the apparatus and having a stem (11) housed in a seat (4) of the spider, the seat extending through a pivotably adjustable element (21) of an articulated joint (22) formed in the spider.

Abstract: A tripod (1) for the support of apparatus in general and, in particular, of optical or photographic apparatus and the like is described and comprises a spider (3) in which a plurality of legs (2) converge and a pillar (12) arranged to receive the apparatus and having a stem (11) housed in a seat (4) of the spider, the seat extending through a pivotably adjustable element (21) of an articulated joint (22) formed in the spider.

Abstract: Selective surfaces for photothermal solar collectors consisting of a nickel support, preferably commercial nickel of 99.5% purity, a layer of a porous nickel oxide of about 0.2 .mu.m covering the metallic support, the layer of porous nickel oxide being covered with asperities in the form of a network of nickel oxide discs in which the major portions are oriented at an angle with respect to the vertical. The network of discs has a thickness of about 2 .mu.m. The preparation of these selective surfaces is carried out in the following manner. Thin nickel plates are subjected to a heat treatment by heating and oxidizing in an oxidant gas during a short period of time at a temperature varying between about 1000.degree. C. and 1100.degree. C. The oxidized nickel plates are reduced at a temperature of about 1100.degree. C. in the presence of a reducing gas until the metallic state is obtained. The surrounding temperature is thereafter lowered between 810.degree. and 830.degree. C.