Alcatel Cit

Societe Anonyme Dite: Alcatel Cit

Luc Mathieu

Jean-Marc Paquet

Sebastien Frindel

Jean-Emile Chollet

Pierre Falcoz

Patrice Deville

Jean-Claude Boivin

A stack of parts, such as the stator disks of a turbomolecular pump, the parts being stacked alternately with spacers, includes a spacer having a knife-shaped deformable portion. When the stack is installed for the first time, the portion is compressed so as to take up the tolerances of the stack between abutment surfaces, e.g. delimited by a pump body and a corresponding casing. The invention applies in particular to turbomolecular pumps and aims to eliminate the operations of adjustment, re-machining, or matching that are usually required when installing a stator assembly.

Spacer of adjustable thickness

A Roots-type machine is connected to an enclosure to be evacuated via a suction inlet portion, and to a primary pump via a delivery outlet portion. A bellows is disposed transversely in the inlet portion, one end of the bellows being fixed in gastight manner in the wall, and the other end being closed and movable, so that the bellows forms a regulating member for regulating the gas-flow sectional area in the inlet portion. The outside face of the movable end of the bellows is subjected to the pressure in the inlet portion, and the inside face of the movable end is subjected to the pressure in the delivery outlet portion via a rod passing through the wall, and via a channel. The invention applies to Roots-type machines, in particular for automatically regulating the pumping speed so as to match it to the flow-rate of the corresponding primary pump.

Gas pumping installation having means for regulating its pumping speed

A valve comprising a valve body (1) provided with two openings (2, 3) each fitted with a flange (4, 5) for connection to pipework, and a moving valve member (6) for closing one of the two openings (3), said opening including a valve seat (26) whose profile corresponds to that of the valve member, said valve member (6) including means (14, 8, 9, 24) for displacing it towards its seat, the valve being characterized by the fact that said valve member (6) or its seat (26) is made of a shape memory alloy treated in such a manner that the shape memory effect is reversible, said piece (6, 26) made of shape memory alloy including channels (27, 31) enabling it to be fed with fluids for changing its state, thereby causing the said piece (6, 26) made of shape memory alloy to expand or contract as appropriate.

Valve

A slide valve comprising: a valve body having two axially aligned openings provided with means for connection in a duct; a drive rod; a valve member; and a backing member; wherein the valve member includes a hollow opening out to both faces of the valve member and fitted with a piston movable between a simple abutment at one end and a shoulder in the hollow at an opposite end, the piston bearing against said shoulder via sealing means, a return spring urging said piston towards said simple abutment, said piston including, at its simple abutment end, means for co-operating with a sloping ramp of said drive rod such that during closure of the valve, the piston is thrust against said shoulder of the hollow.

Slide valve

An anti-return safety apparatus for an installation comprising a vacuum vessel connected to a vacuum pump having an oil seal, wherein the apparatus comprises a valve constituted by a rigid tube having a flexible tube situated therein with the two ends of the flexible tube being fixed in sealed manner to the ends of the rigid tube, a control orifice being provided through the wall of the rigid tube in the vicinity of the middle thereof, the valve being connected between the vessel and the suction inlet to the pump, and in that a slide valve suitable for establishing two different communication paths is provided suitable for establishing a connection between a common outlet C and one or other of two distinct inlets a, and b, the common outlet C being connected to the control orifice of the valve having the flexible tube, the inlet a being connected to the suction inlet of the pump, and the inlet b being opened to atmospheric pressure, the slide valve being electromagnetically controlled by a coil, itself controlled by a relay which is actuated when the motor driving the pump is connected to a power supply voltage, and which is deactivated when the motor is disconnected from the power supply voltage, the slide valve providing communication between its common outlet C and its inlet a so long as the coil is powered, and between its common outlet C and its inlet b connected to the atmosphere whenever the coil is not powered.

Anti-return safety apparatus

A valve comprising a rigid tube in which a flexible tube is situated with the two ends of the flexible tube being connected in sealed manner to the ends of the rigid tube, a control orifice being provided through the wall of the rigid tube in the vicinity of its middle region, and a core also being disposed inside the flexible tube, the core being smaller in cross-section than the inside section of the tube when in the rest state, wherein the core has a calibrated internal passage. The valve is suitable for preventing hammer in an installation having two zones at different pressures P1 and P2.

Valve and apparatus using said valve

A vacuum pump of the type having a Gaede channel, the pump comprising a stator (1) and a rotor (2) driven to rotate inside the stator, the stator including a suction inlet (12) and a delivery outlet (13). The active portion of the rotor situated between the suction inlet and the delivery outlet is hemispherical in shape (9) and is disposed inside a cavity (10) of the stator which is likewise hemispherical in shape. The axis .delta. of said rotor coincides with the said axis of the hemispherical cavity of the stator. Suction takes place at the large circle end of the hemispherical rotor via radial clearance j.sub.a between the rotor and the stator, and delivery takes place at the pole end of the hemispherical rotor. An adjustment distance piece (14) for axially positioning the rotor (2) relative to the stator (1) is provided so that the radial delivery clearance j.sub.r is smaller than the radial suction clearance j.sub.a.

Growing community of inventors

Annecy le Vieux, France

Luc Mathieu