Abstract: A unit for measuring the falling speed of particles in suspension in a fluid comprises a sealed container having an open compartment containing fluid, and a sealed compartment, and, in the sealed compartment, at least three electromagnetic radiation emitters distributed along a longitudinal axis of the open compartment and oriented according to a radiation axis crossing the open compartment at different heights along the longitudinal axis, an equal number of receivers distributed along the longitudinal axis, each receiver placed in the radiation axis of a corresponding emitter, and a system for acquiring data connected to the receivers which is used to obtain the falling speed of the particles and the change of same as a function of the height in the open compartment and as a function of time, said change quantifying the flocculation of the particles.

Abstract: The object of the invention is to improve the performance of the rolls of roughing and finishing stands of a hot strip train or mill and in particular to retard as far as possible the banding phenomenon, namely the phenomenon of the incrusting of hard oxides or scale formed at the conventional rolling temperatures.For this purpose, the roll is made, at least in the working region thereof, from a chrome steel in which the ratio between the respective contents of chromium and carbon is between 7 and 12 and in which the content of equivalent carbon is between 1.5 and 1.7%. This content of equivalent carbon is calculated as the sum of the content of carbon and the content of chromium, the latter being given a coefficient 0.05.

Abstract: A toroidal ring made from a spiral spring with contiguous turns, such as those used for constituting the inner core of a metal sealing ring. The ring has a weld without filling metal connecting together the two end turns of the spring, this weld being such that continuity of the wire of the spring is provided without altering the contiguous configuration of the turns and the mechanical, physical and chemical properties of the spring are substantially unchanged at this weld. The weld can advantageously be effected by a resistance weld performed with a pulse of electric current.

Abstract: The invention concerns a metal seal ring comprising a jacket made of ductile metal intended to be clamped between two surfaces to be applied against each other in a fluid-tight manner and one or two internal spiral springs having close-wound turns made of metal wire, the jacket being provided with a bead in the vicinity of its bearing lines on the surfaces to be applied against each other, the spiral springs are formed with a wire having a cross-section such that it avoids the creeping of the metal of the jacket between the turns in the vicinity of the bearing lines on the surfaces to be applied against each other. Such a seal withstands numerous assembling and dismantling cycles and rises and lowerings of the temperature, without any appreciable loss of its fluid-tight qualities.

Abstract: The invention relates to an assisted hydraulic control, especially for steering all types of vehicles, and comprising a double-acting receiver or hydraulic cylinder, the piston of which forms two chambers in the cylinder, the piston rod extending into one of the chambers only and having no counter-rod extending into the other chamber. The first chamber thus has a smaller effective section than the second chamber, and the resulting asymmetry of operation of the piston and therefore of the steering is compensated by an arrangement in which the distributor valve means of the control, which couples a return conduit to the second of two actuating conduits in a first working position, isolates the return conduit and connects together the second of two pilot conduits, the second actuating conduit and the first actuating conduit in the second working position.

Abstract: The object of the invention is to improve the performance of the rolls of roughing and finishing stands of a hot strip train or mill and in particular to retard as far as possible the banding phenomenon, namely the phenomenon of the incrusting of hard oxides or scale formed at the convenience rolling temperatures.For this purpose, the roll is made, at least in the working region thereof, from a chrome steel in which the ratio between the respective contents of chromium and carbon is between 7 and 12 and in which the content of equivalent carbon is between 1.5 and 1.7%. This content of equivalent carbon is calculated as the sum of the content of carbon and the content of chromium, the latter being given a coefficient 0.05.