Abstract: A protective device for an inertia wheel rotating about an axis and mounted inside an enclosure comprising at least two anchoring frames, wherein the said device comprises a cowling of generally semicylindrical form whose axis is parallel to that of the said wheel and which surrounds the latter and a horizontal arm the first end of which is rigidly fixed near the top of the said cowling and at least three shock absorber sets, one of the said sets being fixed between the second end of the said arm and one of the said frames and operating in a horizontal direction, two other sets being fixed between the lower edges of the said cowling and another frame, while each shock absorber set may operate in both directions.

Abstract: An axial mandrel having good electrical conductivity is fitted with conical metal washers and insulating pastilles in alternate sequence. A nut applied against an insulating support at the lower end of the mandrel exerts a compressive stress on the washers, the peripheral edges of which are applied against a lining sleeve placed within a leaky portion of a heat-exchanger tube. Each washer thus exerts a radial force which applies the sleeve in intimate contact with the tube along a number of circular lines corresponding to the number of washers. An electric current is passed through the mandrel, the washers, the lining sleeve, thus uniting the tube and the lining sleeve by means of circular resistance welds.

Abstract: The shock-absorbing device consists of a plate, a cylindrical ring or an annular ring in which circular holes are formed in uniformly spaced relation so that the same cross-section of constituent material is present in all directions of application of forces during the shock impact.