Patent Number: 051184621
Section: description

Referring now to the figures of the drawings in detail and first, particularly, to FIG. 1 thereof, there is seen a pipe 2 which is introduced into a vessel or container 1 through a nozzle or stub 3. The vessel 1 is surrounded by a biological shield 4 and thermal insulation 5. The biological shield has an opening 6 at the point of discharge of the pipeline, that is rectangular in this case, but may also be round. In the region of the vessel 1 to be tested, the insulation must first be removed before the testing can be performed. This can be done by means of a manipulator 7. The manipulator 7 has a carriage 8, which takes the form of a circular segment and is movable in the circumferential direction of the nozzle 3. A sled 9 is displaceable on the carriage 8 in the axial direction of the nozzle 3. A scissors half 10 which is disposed on the sled 9, has an upper arm 11 supported at one end in a shoulder joint 12 disposed on the sled 9. The other end of the upper arm is connected by another joint 13 to a lower arm 14. A holder 16 for a probe 17 is connected to the free end of the lower arm by a further joint 15. The joints 12, 13, 15 are rotatable about axes that are at right angles to the path of the sled 9 or the axis of the nozzle. Before testing work is begun, the insulation 5 is cut away in the region of the vessel to be tested by means of a cutting or severing tool disposed on the manipulator 7. As FIG. 2 shows, a tool 18, such as a grinder or cutter 18a having a drive motor 18b, is disposed on the holder 16 in order to cut away the insulation. The holder 16 for the tool 18 has a retainer 16a with a fast-action closure element 16b and is connected to the lower arm 14 by the joint 15. The holder can be pivoted by a gear relative to the lower arm 14 by means of a drive motor 15a having position transducers 15b. As seen in FIG. 9, a rack drive mechanism is used to displace the sled 9, to which the scissors half is pivotably attached by the shoulder joint 12. The rack drive mechanism has a drive motor 9a being disposed on the sled 9 and having an angular gear 9c and a pinion 9d, which meshes with a rack 19 secured to the carriage 8. The rack is provided with a toothless guide element 19a for rerailing and derailing the sled 9. This structure permits time-saving installation and dismantling of the manipulator. As seen in FIGS. 8 and 9, in order to adjust the pivoting angle of the upper arm 11, another drive motor 12a is associated with the shoulder joint 12. The pivoting angle of the upper arm 11 is adjustable with the motor 12a through a gear, in particular another bevel gear 12c. Analogously, in order to adjust the pivoting angle of the lower arm, a further drive motor 13a is associated with the joint 13 between the upper and lower arms. The motor 13a enables adjustment of the angle between the upper arm and the lower arm through a gear, in particular a further bevel gear 13c. It is advantageous for the length of the lower arm 14 to be less than that of the upper arm 11, and in particular for it to be approximately two-thirds the length of the upper arm. This makes it possible to fold the arms up against the carriage 8 and thus move the probe 17 into a position in which it is accessible from outside, even under cramped conditions. In this connection, the scissors half is constructed in such a way that the lower arm 14 can be folded back onto the upper arm 11, and the upper arm 11 can be laid flat against the carriage 8. FIG. 3 is a basic illustration showing a manipulator in the folded-up position. In this case, the upper arm 11 and the lower arm 14 are shown with equal length, because there is enough room available for the manipulator. In the position shown, the manipulator can be introduced through the opening 6 of the biological shield 4. Before this introduction, the manipulator is mounted on a non-illustrated installation device in a manner known per se. The device substantially includes divided scissors halves placed around the pipeline 2, with the aid of which the manipulator is thrust into the opening 6. The probe 17 is then easily accessible from outside, as can be seen from FIG. 3. As a result, a change to another probe or tool can be performed in a very brief time, and the radiation exposure to operating personnel can be considerably lessened. In a position that is inclined from the vertical by 45 degrees, there is enough room to fold the lower arm upward as seen in FIG. 4, and to position it against the wall of the vessel 1, as seen in FIG. 5. Through the use of a coordinated motion, in which pivoting of the upper arm 11 and the lower arm 14 and movement of the sled 9 with the joint 15 take place, the manipulator with the probe in place is moved to its maximum projection seen in FIG. 6. From there, the probe can be moved in the circumferential direction of the nozzle 3. To this end, the carriage 8 is rerailed onto an annular rail 20 that coaxially surrounds the nozzle 3. Since the test path runs along a saddle-shaped curve, the sled 9 is displaced axially in the course of the movement of the carriage 8 in the circumferential direction, in such a way that the holder 16 and joint 13 move along the predetermined path, in particular along a path that is at least approximately parallel to the surface to be tested. The electric drive motors 9a, 12a, 13a, which are powered by an electrical power system 21 seen in FIG. 1, are provided as drive mechanisms for the courses of motion, and they are provided with a position transducer 9b, another position transducer 12b and a further position transducer 13b. A control device 22 having a computer is provided for controlling the drive motors. FIG. 7 shows the introduction of the manipulator, in the outstretched position of the arms 11, 14 with the probe 17 oriented toward the vessel 1. The manipulator can be introduced in this position even when only a very small opening in the biological shield and only a narrow annular gap 23 are available. A practical embodiment of a manipulator 7 for handling operations can be seen from the side and end views of FIGS. 8 and 9. The carriage 8 is supported on the annular rail 20 by means of pairs of rollers 20a, 20b and is driven by an electric motor 24 having position transducers 24b. The motor 24 acts through a pinion 24a on a rack 20c. The carriage 8 has a base plate 25 on which two guide rails 26, 27 for guiding the sled 9 and the rack 19 are disposed, parallel to the axis of the nozzle. Guide rollers 28, 29 having a prism-shaped groove are rotatably supported on the sled 9 and engage a prism-shaped protrusion on the guide rails. Associated with the rack 19 is the pinion 9d, which is driven by the motor 9a that has the position transducers 9b and is secured to the sled 9. The probe 17 disposed on the tip of the scissors half has the retainer 16a with the fast-action closure 16b and is suspended in a gimbal mounting on the lower arm 14 through the joint 15.