Abstract: The driving pulley comprises two centrifugal mechanisms, namely a positive assembly and a negative assembly. Both assemblies comprise a respective set of flyweights subjected to the centrifugal force when the driving pulley rotates. The positive assembly is used as a conventional speed governor that moves one of the two flanges of the driving pulley towards the other in order to increase its winding diameter when the rotation speed increases. The negative assembly is used to apply an opposite force on the positive assembly when the rotation speed is above a threshold value so as to defer the upshift of the CVT to a higher ratio under the action of the positive assembly. This allows to maintain, for instance, a high rotation speed during an intense acceleration and a lower rotation speed when cruising at low vehicle speeds.

Abstract: The driving pulley comprises two centrifugal mechanisms, namely a positive assembly and a negative assembly. Both assemblies comprise a respective set of flyweights subjected to the centrifugal force when the driving pulley rotates. The positive assembly is used as a conventional speed governor that moves one of the two flanges of the driving pulley towards the other in order to increase its winding diameter when the rotation speed increases. The negative assembly is used to apply an opposite force on the positive assembly when the rotation speed is above a threshold value so as to defer the upshift of the CVT to a higher ratio under the action of the positive assembly. This allows to maintain, for instance, a high rotation speed during an intense acceleration and a lower rotation speed when cruising at low vehicle speeds.

Abstract: The driven pulley (10) is used in a continuously variable transmission (CVT). It is coaxially mountable around a main shaft (12) and comprises two opposite conical flanges, namely a first flange (14) and a second flange (18), which face each other. An annular cam plate (40) is coaxially connected to the side of the second flange (18) that is opposite the first flange (14). The cam plate (40) comprises at least two inclined first cam surfaces (42) and at least two inclined second cam surfaces (44) having an inverted inclination with reference to the first cam surfaces (42). A first radially-extending support (50) bears a set of first cam followers (54). The first support (50) is at a fixed axial distance from the first flange (14) and each first cam follower (54) is engaged with a respective one of the first cam surfaces (42). Similarly, a second radially-extending support (60) bear a set of second cam followers (64).

Abstract: A nuclear fuel rod assembly storage rack comprises a rigid structure delimiting vacant spaces of square, cross-section and neutron-absorbing units also having a square cross-section prearranged before introduction into all or part of the vacant spaces between the shroud tubes. Each neutron-absorbing unit is made up of four flat plates of neutron-absorbing material, surrounded by at least two support grids. The support grids may comprise two units assembled together, for example by welding.

Abstract: A storage rack for nuclear fuel assemblies and its manufacturing process.A storage rack for nuclear fuel assemblies is formed by assembling main plates (12), spacer plates (14), two end plates (16) and a base plate (18), preferably by welding. Once a first main plate (12(1)), a first end plate (16(1)) and the base plate (18) have been mounted on a tooling, a first series of housings (10) is formed by securing a first row of spacer plates (14(1)) to the first main plate (12(1)), and then mounting a second main plate (12(2)). The other rows of housings (10) are obtained in the same manner. The rack is completed by mounting the second end plate.

Abstract: An installation, designed to stock both nuclear fuel assemblies of square section and control bars of cruciform shape taken from a boiling water nuclear reactor, comprises vertical housings of square section, each able to accommodate a control bar and four assemblies. The housings are formed in and between encasing tubes (22) which rest upon a lower plate (10). After placing a control bar in the housing, a removable unit (30) is inserted which comprises a baseplate (34) surrounding the tip of the bar, four holders (32) resting on this baseplate, and spacer wedges (36) separating the holders. One assembly is then placed in each holder (32).

Abstract: In a driven pulley used in a variable speed transmission adapted to receive a trapezoidal belt by which power is transmitted from a driving pulley to the driven pulley having a fixed flange, a movable flange and an internal helicoidal spring, there is provided a set of flyweights forced by torsion springs on an annular-conical surface located at the rear of the movable flange. At the minimum rotation speed, the driven pulley generates a high gripping force but as the rotation speed increases, the centrifugal force acting on the flyweights lowers the force exerted by the trapezoidal belt. At a given high rotation speed, the flyweights leave the annular-conical surface and no longer contribute to counterbalancing the radial force exerted by the trapezoidal belt, the helicoidal spring and the internal resultant forces acting alone. The improved driven pulley generates a high initial gripping force while having a reasonably low gripping force at high speed for good efficiency.

Abstract: A pulley mounted at the output of a drive shaft is used in a variable-speed belt drive in which pairs of generally cylindrical toothed flyweights engage toothed racks in order to vary the winding diameter of the pulley by varying the centrifugal force. A V-belt is placed around the pulley. As a result of using the pulley, a more accurate adjustment of the diameter is achieved, maximum engine power is maintained under conditions of severe loading, and the response time of the diameter varying system is reduced in the case of an abrupt load change.

Abstract: In a driven pulley used in a variable speed transmission adapted to receive a trapezoidal belt by which power is transmitted from a driving pulley to the driven pulley having a fixed flange, a movable flange and an internal helicoidal spring, there is provided a set of flyweights forced by torsion springs on a conical ring located at the rear of the movable flange. At the minimum rotation speed, the driven pulley generates a high gripping force but as the rotation speed increases, the centrifugal force acting on the flyweights lowers the force exerted by the trapezoidal belt. At a given high rotation speed, the flyweights leave the conical ring and no longer contribute to counterbalancing the radial force exerted by the trapezoidal belt, the helicoidal spring and the internal resultant forces acting alone. The improved driven pulley generates a high initial gripping force while having a reasonably low gripping force at high speed for good efficiency.

Abstract: In a driven pulley used in a variable speed transmission adapted to receive a trapezoidal belt by which power is transmitted from a driving pulley to the driven pulley having a fixed flange, a movable flange and an internal helicoidal spring, there is provided a set of flyweights forced by torsion springs on an annular-conical surface located at the rear of the movable flange. At the minimum rotation speed, the driven pulley generates a high gripping force but as the rotation speed increases, the centrifugal force acting on the flyweights lowers the force exerted by the trapezoidal belt. At a given high rotation speed, the flyweights leave the annular-conical surface and no longer contribute to counterbalancing the radial force exerted by the trapezoidal belt, the helicoidal spring and the internal resultant forces acting alone. The improved driven pulley generates a high initial gripping force while having a reasonably low gripping force at high speed for good efficiency.

Abstract: A driving pulley used in a variable speed transmission is adapted to receive a trapezoidal belt by which power is transmitted from the driving pulley to a driven pulley. The driving pulley is provided with radial pins connected to the shaft and movable inside respective apertures delimited by ramps for limiting sliding and rotating movements of the movable flange within predetermined limits with respect to the shaft and for imposing a specific mechanical behavior to the movable flange. It allows additional control of the engine speed under full throttle, reducing the overrun and helping the transmission return to its smallest ratio during a quick vehicle slowdown.