Patent Number: 048866350
Section: description

Referring now to the figures of the drawings in detail and first, particularly, to FIG. 1 thereof, there is seen a gripping tool 2 that can be connected to the lower end of a mast 1 which can be suspended from a crane. The mast 1 has a first coupling half or part or connecting member 1a in the form of a pin which can be inserted into an opposite coupling half or part or connecting member 2a in the form of a sleeve. The sleeve 2a is retained on the top of the pin 1a by means of a bolt 3. A guide bar 4 is spring-mounted with telescope-like placement or suspension in the bottom of the sleeve 2a. A pressure spring 24 which is disposed in the sleeve 2a has one end braced on a partition 2b and the other end on the front surface of the guide bar 4. The travel of the spring is defined by an oblong hole 4a. A bolt 4b which is fixed in the sleeve 2a extends through the oblong hole 4a. On the other end of the guide bar 4, catches 5, 6 in the form of a two-armed lever are disposed in respective pivots 7, 8. The catches 5, 6 are used to grasp a head 10 which is disposed on a capsule 12 by means of a retainer 11 and in which a sample or specimen is placed. A bolt 10a protrudes from the head 10. The inner surfaces of the catches 5, 6 have gripping surfaces 9 adapted to the shape of the head 10 so that they grasp the head 10 in a form-locking manner when they are in the closed position. A form-locking connection is one which connects two elements together due to the shape of the elements themselves, as opposed to a force-locking connection, which locks the elements together by force external to the elements. The guide bar 4 is surrounded by a sleeve bushing or 13 having guide pins 14, 15 which engage respective guide grooves 5a, 6a of the catches 5, 6. The guide pins 14, 15 are fixedly disposed on a lateral support 16 of the sleeve 13 as seen in FIG. 2, and can be moved in the direction of the longitudinal axis of the sleeve by means of a remotely-controllable linear drive acting on a flange 17 of the sleeve. The linear drive is advantageously in the form of a pressure medium drive in which cylinders 19 with pistons 20 are disposed on a flange 18 of the guide bar. The pistons 20 are each connected through a piston rod 21 with the flange 17 of the sleeve 13. The cylinders 20 are supplied with compressed air or a hydraulic medium through control lines 22b for opening the catches 5, 6 and through control lines 22a for closing the catches 5, 6. Return springs 23 which are additionally installed in the cylinders 19 assure that the pistons 20 remain in the upper position and the catches 5, 6 remain closed, in case of a sudden reduction of pressure in the control lines 22a. In order to remove the sample by remote control, the control lines 22 are linked with a pneumatic system in which the pressure lines connected with the cylinders 19 are connected with a pneumatic reservoir 25 through a shift device 26 disposed in a control panel. An operational check of the gripping tool 2 is then performed while the mast 1 is suspended from the crane. If the piston rods 21 are extended, the catches are open. The gripping tool 2 is lowered in this position by the crane until it rests on the head 10 of the retainer 11 of the capsule 12 for the sample. The protruding bolt 10a completely retracts elastically. An additional strong damping of the shock occurring when the gripping tool 2 is seated and avoidance of damage to the radiation column are achieved due to the fact that the guide bar 4 is yieldingly seated in a telescope-like manner in the sleeve 2a by means of the spring 24. After the gripping tool has been seated, the pistons 20 are retracted by charging the control lines 22a so that the catches 5, 6 close in a form-locking manner around the head 10, as seen in FIG. 2. A form-locking connection is one which connects two elements together due to the shape of the elements themselves, as opposed to a force-locking connection, which locks the elements together by force external to the elements. The radiation sample can then be pulled and suspended in a fuel assembly reservoir. The return springs 23 assure that the catches 5, 6 remain closed if accidental reduction of pressure occurs in the pressure medium lines 22 during transport by the crane. In order to open the catches, the piston rods 20 are extended by supplying pressure medium to the control lines 22b.