Abstract: A rotary and sealed connection for pressurized fluids is provided, including a first part that is secured, for example, to a fixed source of pressurized fluid and has a recess for communication therewith and through a second part, with a fluid-using rotary apparatus of revolution rotating about a shaft and extending through the first part through a passage, said second part having a degree of radial freedom and being held in position without play by a seal serving as a bearing. The annular space in the passage may thus be extremely reduced, thus avoiding any risk of extrusion of the seal.

Abstract: Controller for a cooling system utilizing the Joule-Thomson effect for a cryostat, wherein the expansible component consists of a metal rod (20) of very small diameter, inside and coaxial with the tubular envelope (7), one end (21) of this rod (20) is fixed mechanically, and is joined thermally by a transverse bulkhead (22), to the tubular envelope (7) at a point of the latter lying between the warm point and the cold point (10), the other end (23) of this rod is fixed to a fork (16) for operating the needle (13) surrounding the seat (11,12) of the needle and driving the needle (13) through the intermediary of an adjustment component (18), and lastly the said fork (16) incorporates a periphery, preferably cylindrical, which leaves a large annular gap between this periphery and the inside surface of the envelope tube (7).

Abstract: Device comprising an inlet duct for a gaseous refrigerating fluid under pressure connected to a choke opening into a fluid expansion and liquefaction chamber connecting with a refrigerating fluid discharge passage which exchanges heat with the said inlet duct, characterized in that, for the pressure range involved, the minimum opening (15) of the choke (10) and the heat exchange relationships with the inlet duct (7, 8) are such that in the minimum opening operating phase a liquefaction phase arises in the inlet duct upstream of the choke, so producing self-regulation producing the fluid flow just necessary to maintain liquefaction in the expansion and liquefaction chamber.

Abstract: Device for regulating a Joule-Thomson effect refrigerator comprising an inlet duct for a refrigerating fluid under pressure to which a choke is connected which opens into an expansion and refrigeration chamber connecting with a passage for heat exchange with the said inlet duct, this choke being regulated to provide a decreasing flow as the refrigeration temperature drops by applying differences in the coefficients of expansion of the components making up the device, characterized in that the said choke, for this purpose, consists in a tubular body (8) connected to the said inlet duct (4) and in which an inner body is held (9, 9a), providing a passage cross-section in it which is regulated by the difference in the coefficients of expansion of the materials making up these two bodies.