Patent Number: 052710467
Section: description

Referring now to the figures of the drawing in detail and first, particularly, to FIG. 1 thereof, there is seen a pipeline 2 which is introduced into a vessel 1 through a connection piece or pipe 3 and is joined to it by welding. The vessel 1 is surrounded by a biological shield 4 and a thermal insulation 5. At the entry point of the pipeline 2, the biological shield 4 has an opening 6, which is typically rectangular in shape. As can be seen in FIGS. 1 and 2, a manipulator 7 includes two trolleys 8, 9 that are movable circumferentially around the connection piece 2, and a jointed-shank arm 10 which pivots like scissors. This jointed-shank arm 10 has two shanks 11, 12, which are each supported at one end in a respective hinged support 13, 14 disposed on the trolleys 8, 9, with the hinged support being constructed as a cardan joint or ball and socket joint. The other ends of the shanks 11, 12 are joined together by a crown hinge 15. A support 16 with a test head 17 is disposed on the crown hinge 15. The crown hinge 15 advantageously includes one toothed ring segment 11a, 12a on the end of each respective one of the shanks 11, 12. The toothed ring segments 11a, 12a mesh with one another. Center points of the toothed ring segments 11a, 12a are each supported in a respective pivot pin 16a, 16b. The pivot pins are mounted on the support 16. As a result, the support 16, upon a change in the angle between the two shanks 11, 12 and a resultant radial motion of the crown hinge 15, is always aligned in the axis between the shanks 11, 12 bisecting that angle. In other words, it maintains its same angular position. The trolleys 8, 9 have the shape of a segment of a circle and are movable along an annular rail 26 circumferentially of the pipe 2. The trolleys 8, 9 are supported on the annular rail 26 by means of pairs of rollers 27a, 27b and are each driven by a respective electric motor 18, 19 with position encoders 20, 21. The motors 18 and 19 each act through a respective pinion 28a (28b) on a common circular rack 29. A respective base plate 30a, 30b is disposed on each of the trolleys 8, 9, and a respective guide rail 31a, 31b is clamped thereon parallel to the axis of the connection piece 3 by means of a respective clamping device 31c, 31d. The jointed-shank arm 10 can be introduced on the guide rails. The guide rails 31a, 31b also serve to fix a distance between the hinged supports 13, 14 and a wall of the vessel 1. The hinged supports 13 and 14 of the jointed-shank arm are each connected through a respective web 13a, 14a to a shoe, 32a, 32b, which is guided adjustably in the axial direction of the pipe 2 in a dovetail-like recess of the respective guide rail 31a, 31b. A locking device 33a, 33b serves to fix the position. One spring means 22, 23 is disposed between each of the shoes or carriages 32a, 32b and a respective one of the shanks 11, 12, in order to press the test head 17 or a tool against the wall region to be tested. The spring means 22, 23 may preferably be constructed as pneumatic or hydraulic cylinders. As FIG. 3 shows, a pivot pin 34 is disposed on the web 13a and a bracket 35 is rotatably supported on the pivot pin 34. An eyelet 36 is disposed on the bracket 35 for rotatably retaining the spring means 22. A pivot pin 37 on which the shank 11 is supported, is also secured to the bracket 35. The configuration forms a cardan joint. At least one angle encoder 24 and/or 25 for detecting the inclination of at least one of the shanks 11 or 12 relative to a reference plane, is provided on the hinged supports 13, 14. The motors 18, 19, the associated position encoders 20, 21 and the angle encoders 24, 25 are connected to a control device 34' containing an arithmetic unit 35', for the trolleys 8, 9. The crown hinge 15 is moved radially into a predetermined position by varying the position of at least one of the trolleys 8, 9, by means of the control device 34' acting upon the drive motors 18, 19. By moving both of the trolleys 8, 9 simultaneously and in the same direction, the test head 17 or a tool can be moved along a curve having a center which is located in the axis of the connection piece 3. Through the use of a different coordinated control of the drive motors 18, 19, an arbitrary testing path can be established in the radial direction and in the circumferential direction of the connection piece. For removal (tool changing, test head changing), the two trolleys 8, 9 are moved far enough apart that the jointed-shank arm 10 rests almost on the connection piece 3 (in the position shown in dashed lines in FIG. 2). The spring means 22, 23 are then relaxed, or the pneumatic or hydraulic cylinders are retracted, so that the test head 17 no longer rests on the vessel wall and the jointed-shank arm 10, after release of the clamping device 31c, 31d, with the guide rails 31a, 31b, is removed from the opening 6.