Ultrasonic testing system with variable angle transducer mount

#This invention relates generally to the field of ultrasonic testing, and more specifically to signal transmitting equipment and methods.

#When focusing signals in ultrasonic testing, it often becomes necessary to transmit the signal beam at an angle to the mounting surface. In the existing prior art, angle beam transducers are manufactured at fixed wedge angles. When a change in the angle of observation (or focal point) is required, the transducers must be detached from the fixed wedge angle and reattached to the desired, different wedge angle. Multiple wedge sets must always be on hand; and, even then, the wedge angles are limited by manufacturers to standard effective angles of, for example, 30, 45, 60, 70 and 90 degrees.

#Briefly described, the present invention comprises an apparatus and method wherein a single transducer is mounted for rotational and angular movement within a housing to thus provide a range of varying wedge angles without exchanging wedge elements. The apparatus of the present invention, in the preferred embodiment, includes a transducer search unit mounted to a ball joint housed within a housing such that the search unit moves as the ball joint moves within the housing. The transmitter end of the search unit is immersed during operation, and throughout its range of movement, in a fluid occupied chamber bordered at one wall by a flexible membrane.

#FIG. 1 is an exploded view of a variable angle transducer mount in accordance with the present invention.

#FIG. 2 is a partially cut-a-way side view of the mount in FIG. 1, cut along line 2--2 of FIG. 1.

#FIG. 3 is a side view of the variable angle transducer mount of FIG. 1 strapped for use to a valve housing, in accordance with the present invention.

#Referring now in greater detail to the drawings, in which like numerals represent like components throughout the several views, the present invention is seen as comprising a variable angle transducer mount 10 shown in exploded detail in FIG. 1. The transducer mount 10 comprises a housing 12 formed with a large cylindrical central channel 14, a flat top rim 15, flat bottom rim 16 and an outer wall 18. The outer wall 18 defines an upper segment which is wider in cross-section (see FIG. 2) than the bottom rim 16, and a tapered, lower segment 20. At the bottom rim 16, a circular ledge 25 is formed protruding into the central channel 14. Three, parallel, internally threaded bores 23 extend from the top rim 15, through the upper wall segment 19 and break the surface of the housing 12 through the tapered, lower segment 20. A threaded pin 24 occupies the bottom end of each of the bores 23, and protrudes from the tapered wall segment 20. The amount of protrusion of the pins 24 is adjustable by virtue of the threaded nature of the bores 23 and pins 24. Two strap holding pins 27 are mounted at the upper wall segment 19. The housing 12 is also formed with a threaded screw hole 28 extending generally perpendicular to the cylindrical axis 31 of the central channel 14, from the outer wall 18 through the upper segment 19 and into the central channel 14. A flat-end screw 29 occupies this screw hole 28 and is of sufficient length to extend from the outer wall 18 to the central channel 14. An eyelet 30 is bolted to the upper wall segment 19; but its bolt portion does not extend into the central channel 14.

#A disk shaped membrane 34, of diameter greater than the inside diameter of the circular ledge 25 is placed in the central channel 14, resting on the circular ledge 25. A spacing washer 35 is set on top of the membrane 34 and is supported by the circular ledge 25, thus sandwiching the peripheral edge of the membrane between the washer and the circular ledge. A ball joint assembly 42 is set into the central channel 14 atop the washer 35. The ball joint assembly includes a rim segment 44 and a ball segment 45. The rim segment 44 includes a cylindrical outer wall 47 of diameter, preferrably, only slightly less than the inside diameter of the central channel 14. The rim segment 44 also includes an inner passage 48 formed to accept the ball segment 45 in a manner typical to ball joint assemblies. The ball segment 45 is mounted in the inner passage 48 and enjoys complete rotational and pivotal freedom within the rim segment 44, as is typical of ball joint assemblies. The ball segment 45 is provided with a central, cylindrical passage 50 extending completely through the center of the ball segment. A threaded element 52 is press-fitted into the cylindrical passage 50 of the ball segment 45. A hole 46 is drilled through the rim segment 44 perpendicular to the cylindrical axis of the outer wall 47 and extending from the outer wall 47 through to the inner passage 48. The hole 46 is filled with a plug 49 which, preferrably, extends the full length of the hole. In preferred embodiments, the plug is formed of brass. When the ball joint assembly 42 is set into the housing channel 14, the hole 46 of the rim segment 44 is aligned with the threaded screw hole 28 in the housing.

#A clamp plate 55 is set on the top rim 15 of the housing 12. The clamp plate 55 is formed with a central opening 56. In the disclosd embodiment, the central opening 56 is circular, having an inside diameter which is less than the inside diameter of the central channel 14 of the housing 12. The inside diameter of the opening 56 is sufficiently large to avoid contact with the ball segment 45 as it pivots in the rim segment 44 of the ball joint assembly 42. The clamp plate 55 is held to the rim 15 of the housing 12 by screws 58 extending into the threaded bores 23 of the housing 12. As seen, the screws 58 occupy the same bores 23 as the threaded pins 24.