Abstract: A metrological instrument includes an inductive transducer having a stylus, all being disposed within a protective housing. Upon initiation of the measuring operation, the transducer is moved so that the stylus moves round an endless path such that the stylus is first projected at a high speed from the housing, is thereafter moved to engage the workpiece surface, is then moved at relatively slow speed across the workpiece surface for performing the measurements, and, following completion of the latter movement, is retracted at a high speed into the housing. These movements are effected by a series of cams driven by a single motor. Such an instrument may be located next to a production line without risk of damage and may used for the checking of each of a multiplicity of identical components produced in a mass production process.

Abstract: An inspection gage includes an expandable tubular member insertable within a fuel assembly guide thimble. The tubular member has embossments circumferentially spaced from one another about the tubular member and being the same in number as bulges on the guide thimble and configured to fit therewithin. An expansion member rotatably mounts the tubular member and is axially movable therewithin when the latter is inserted within the guide thimble. The expansion member is movable between a first position in which it permits inward contraction of the tubular member an displacement of its embossments away from the guide thimble bulges for removing the embossments from registry therewith and a second position in which it produces radial expansion of the tubular member and displacement of its embossments toward the guide thimble bulges for placing the embossments in registry therewith.

Abstract: The remote measurement device comprises a supporting structure (5) consisting of a plane annular base connected to the end of a handling pole of great length, and a movable measuring assembly carried by the base (5) and consisting of a stage (30) movable in all directions of the plane of the base coming to rest on the plate (3). The stage (30) is integral with a tubular sleeve (36) the axis of which is perpendicular to the plane of the stage (30), and the supporting structure (5) has a thrust assembly (18) abutting against the outer surface of the sleeve (36). A tracer (38) with a movable rod is mounted on the sleeve (36), with its rod (40) in a radial direction and pointed towards the interior of the sleeve (36). For measurement, the sleeve (36) is slipped onto the cylindrical element (4), and the thrust assembly (18) moves the sleeve (36) and the stage (30) forming the movable measuring assembly as a result of a radial thrust exerted on the sleeve (36) in a zone diametrically opposite the tracer (38).

Abstract: An apparatus for an integrated and automated fuel assembly inspection system includes a support base, an elongated fixture, top and bottom carriages and a pedestal. The top carriage is mounted to a pair of tracks on the fixture for vertical movement therealong. The pedestal is mounted on the base and aligned with the top carriage for supporting a nuclear fuel assembly therebetween. The bottom carriage has a central opening adapted to receive the fuel assembly therethrough such that the bottom carriage surrounds all sides of the fuel assembly. Also, the bottom carriage is mounted to the tracks for generally vertical movement along the fixture and the fuel assembly. D.C. stepping motors are mounted on the top and bottom carriages and coupled to a gear track for selectively driving the carriages along the fixture.

Abstract: Device for checking the vertical alignment of the upper and lower internal equipment of a pressurized water nuclear reactor comprising a vertical tubular body (14) onto which are fixed a flange (15) for centering the upper internal equipment on the upper plate (2), a flange (16) for centering on the upper core plate (3) and a lower end member (17) which enables the device (1) to be centered on the lower core plate (4). A metal wire (24) is aligned along the axis of the tubular body (14), its lower part being fixed to the end member (17) and its upper part to a fitting (20) which can move in two horizontal directions at 90.degree.. Electrodes are arranged in the flange (16) around the wire (24), to detect, by virtue of an electrical monitoring circuit (90), contact between the wire (24) and the electrodes when the upper part of the wire is moved by the fitting (20).

Abstract: A method of repairing under water a boiling water reactor-fuel assembly having a fuel assembly channel and an upper grid plate by means of a channel stripping machine, disassembling the upper grid plate, determining a damaged fuel rod and exchanging the damaged fuel rod for another fuel rod by means of a fuel rod exchanging device, which includes, after stripping off the fuel assembly channel and disassembling the upper grid plate at the location thereof in the channel stripping machine, placing on the fuel assembly a guide box with which the fuel rods of the fuel assembly are centered, then placing thereon an indicator plate and determining the varying growth of the fuel rods, and replacing the indicator plate by a centering plate to which the fuel rod-exchanging device is coupled and a device for carrying out the method.

Abstract: The invention features a device for gauging the category to which a length of yarn belongs. The device comprises a flat sheet having a plurality of elongated transparent regions. Each region corresponds in width and contour to a length of yarn from a specific category of yarn, when the length is pulled to lie in a straight line.

Abstract: With the reactor vessel (1) open and filled with water, and the core assemblies removed, means for measuring alignment (50) and means for measuring clearances (56, 58, 59) are mounted on the upper internal equipment (13). The upper equipment (13) is introduced into the vessel and is deposited on the lower equipment (3). Measurements of alignment are carried out and, if appropriate, the alignment is corrected by moving the upper internal equipment on the lower equipment (8). The clearances of the upper core plate are measured and, if appropriate, the upper internal equipment (13) is moved as a function of these measurements. The clearances around the centering and alignment pins are measured and adapters are machined and then fixed to the upper internal equipment (13) to reduce the clearances around the pins to a low, predetermined value. The invention also relates to the device for measuring and adapting the position of the internal equipment.

Abstract: Device for measuring clearance around a pin for centering the upper internal equipment of a pressurized water nuclear reactor comprising a carrier (b) fixed integrally to a pedestal (7) which makes it possible to fix on the upper plate of the reactor core (1) two travellers (15) which are parallel to the plate (1), two slides mounted to move on the travellers, resilient means (22) for returning the slides and a marking assembly carried by the carrier. Each slide comprises a sensing finger (30) projecting downwards relative to the bearing face of the pedestal (7) and a planar marking plate (31). The marking assembly comprises two styli (33), each directed towards a marking plate (31). A control system (34) makes it possible to compress springs (36) whose force is applied to the styli (33). The clearance measurement can be carried out from a distance and under water.

Abstract: A measuring rule including a numerical counter with a tapered knurled shaft mounted for rotation, a rotating spool having an elongated cord wound around it and spring bias means for rewinding the cord around the spool. Stop means are provided for automatically preventing rewinding of the cord about the spool until the stop means is disengaged by the user of the rule, while permitting the cord to be freely pulled off the spool. The cord passes from the spool around the knurled shaft to turn it and the counter as the cord is pulled off the spool, through the stop means and out of the housing so that the length of cord pulled out of the rule and passing around the knurled shaft is indicated by the numerical counter. Error correcting means are further provided for adjusting the location where the cord passes around the tapered shaft along its length.

Abstract: A method of selecting values for parameters in a calibration map used to correct for measurement errors. The locations of points in a grid on an uncalibrated calibration plate are measured for different orientations of the calibration plate. The parameters in the calibration map and the parameters relating the orientations of the calibration plate are determined to minimize the deviation from congruence of the image under the calibration map of the grid in each orientation. The orientations should be related by rigid motions having rotation axes that are separated sufficiently to remove uncertainties in the calibration which arise if the rotation axes are all collinear or nearly collinear.

Abstract: The invention pertains to a linear variable differential transformer (LVDT) probe utilizing a core mounting upon a sensing rod axially translatable with respect to a coil. The coil is movably supported for initially aligning the core and coil in a predetermined relationship to produce a desired electrical situation, such as a null condition, and the probe utilizes alignment means for quickly initially aligning the core and coil.

Abstract: This invention contemplates a rapid method of calibrating probe-pin combinations, such as star probes or rotary-swing probes, which method is applicable when the probe system forms part of or is coupled to the control system of a measuring machine wherein a self-centering probe of workpieces is possible. The calibration procedure employs a calibration standard having a plurality of probe-centering elements distributed over its surface and facing in different directions, the positional geometry of these elements being stored in the computer of the measuring machine. Each of the individual probe balls is successively introduced into a centering element which is accessible. Thereupon, the position of each ball-center point is determined in the computer, from the stored positional data and the pre-established diameter of corresponding probe balls.