Abstract: A control mechanism for moving switch points on a railroad track, having a drive screw driven by a motor, a traveling block moving along the drive screw to position the switch points, an end stop on the drive screw for limiting movement of the traveling block, a hand crank for manually turning the drive screw, and a torque limiting clutch on the hand crank.

Abstract: A sub-assembly for a spacer in a nuclear fuel bundle includes at least first and second ferrules lying adjacent one another for receiving respective nuclear fuel rods. Each ferrule has fuel rod contacting points along one side of the ferrule for abutting a fuel rod within the ferrule, and a substantially I-shaped opening along a side of the ferrule opposite the one side. A substantially I-shaped spring adapted to seat within the opening includes a spring body lying in a plane and having opposite horizontal end portions connected by a vertical stem portion, a central portion of each of the horizontal end portions projecting away from the substantially I-shaped opening to one side of the plane and a center portion of the vertical stem projecting into the substantially I-shaped opening to an opposite side of the plane.

Abstract: The spacer comprises a plurality of strips interleaved with one another to form an eggcrate-type pattern defining essentially rectilinear cells for each fuel rod. Each strip includes a central body portion with cantilevered loop spring-like projections extending to opposite sides, with spring contact portions projecting inwardly. Stops are provided along each of the central body regions of the strips intermediate the loop springs that project to the opposite side of the strip. Adjoining walls have loop spring portions for biasing the rod into engagement with opposing stops whereby each fuel rod is supported at six contact points, i.e., four spring contact points and two hard stop contacts opposite the paired spring contacts.

Abstract: The spacer for a nuclear fuel bundle includes unit cells having upper and lower, generally octagonally shaped walls connected one to the other by spring leg portions along sides thereof 90.degree. apart. The walls also carry stops in opposition to the sides of the walls to which the spring leg portions are connected. By orienting the cells in the spacer such that the majority of the cells have their stops lying toward one side of the spacer, the fuel bundle can be disposed in a horizontal position on the one side of the spacers. In that manner, the dead load of the fuel rods and spacers is borne by the stops along the underside of each spacer without substantially loading the springs of the spacer cells.

Abstract: In a nuclear reactor fuel bundle assembly having a plurality of fuel rods and a non-round water rod extending between upper and lower tie plates, and having at least one fuel rod spacer located along the non-round water rod, an improvement which includes cooperating components on the fuel rod spacer and on the water rod for permitting movement of the spacer along the water rod to a desired axial location and for thereafter preventing further axial movement of the spacer in at least one of two opposite axial directions, the cooperating components including at least one spring on one of the spacer and the water rod.

Abstract: A spacer for a nuclear fuel bundle comprises a plurality of discrete, generally cylindrical ferrules, with each ferrule having a pair of circumferentially spaced fuel rod contacting portions along one side of the ferrule and three superposed openings in the ferrule along an opposite side thereof. A leaf spring having opposite end projecting portions and a central projecting portion is disposed between adjacent ferrules with the end projecting portions and the central portion disposed within the openings of the ferrule. The central portion includes a boss projecting inwardly for engagement against the fuel rod in one ferrule and the end projections contain bosses projecting inwardly and spaced from the fuel rod of the one ferrule. The end projections bear against an adjacent ferrule. The spring is captured between the two ferrules and contacts the ferrules at a plurality of laterally and vertically spaced contact points so that the spring is stabilized against flow-induced vibration.

Abstract: A fuel bundle assembly for a nuclear reactor includes a lower tie plate; a transition piece underlying the lower tie plate; a plurality of fuel rods and at least one water rod seated on the lower tie plate and extending in substantially parallel relationship toward an upper end of the fuel bundle assembly, wherein a fuel bundle assembly lifting load is carried by load bearing members including certain of the fuel rods or by the at least one water rod; a plurality of spacers axially spaced along the at least one water rod and including means for laterally supporting each of the fuel rods; and a handle bar assembly at the upper end of the fuel bundle assembly connected to the load bearing members such that the plurality of non-load bearing fuel rods are supported only by the lower tie plate and the plurality of spacers.

Abstract: A spacer includes a plurality of ferrules welded to one another to form a structural integral matrix for locating fuel rods in a fuel bundle. Each ferrule has a pair of stops along one side of the ferrule and a central opening along its opposite side. An elongated flat spring having openings straddling a central cross-piece is disposed along an outer edge of the ferrule with the spring openings receiving band portions of the ferrule above and below the opening through the ferrule. The intermediate cross-piece bears against an adjoining ferrule whereby the end portions of the spring bear against the rod in the one ferrule, biasing it against the opposite stops. Thus ferrule/spring construction reduces the quantity of material of the ferrule, thereby improving performance without sacrificing structural integrity.