GB1046774A - Improvements in ultrasonic flaw detection equipment - Google Patents

Abstract

1,046,774. Ultrasonic testing. GLASS DEVELOPMENTS Ltd. April 26, 1963 [April 27, 1962], No. 16197/62. Heading H4D. In an ultrasonic flaw detection arrangement in which the test object is scanned by movement of a probe the probe is supported by a carriage which moves to impart one component of scan, the other component of which is effected by moving the probe with respect to the carriage. Figs. 1 and 2 show one embodiment in which the test object comprising a plate 15 supported in a water-filled tank 10 (which may be drained by sluices 11) is scanned by an ultrasonic test probe 25 which oscillates to-and-fro in a slot 24 provided in a plate 22, the latter, together with the portion 17 forming a gantry which is moved parallel to the longer dimension of the plate 15 along track 18. The electrical conductors supplying the probe are supported by a carrier 26 and pass to a cable trough 27 running the whole length of the tank. The scanning motion may be produced by electric motor means or by manual means. In the case of the former an electric motor 33 (see Fig. 2) operating via a speed-control device 34 (adjustable by means 35) effects continuous movement of endless chains 44 which are coupled to the probe carriage 45 such that the latter oscillates backwards-andforwards to produce one component of scan, the other of which is effected in pinion 20 coacting with a rack 19 adjacent track 18. For manual operation the two components of scan are effected by means of control elements 48, 49, respectively. The gantry also carries a recorder 28 the motion of the stylus of which may be effected by coupling it to the probe carriage 45 by means of a chain whilst the motion of the recording paper 29 is produced by movement of the gantry. The latter, additionally, carries a cathode-ray tube indicator 30 producing an A or B scan (or both types of presentation) and an alarm unit 31 to stop the control mechanism or detection of a flaw and warns the operator. In a second embodiment the probe 25 (Fig. 3) counterbalanced at 59, is rotated about a vertical axis by means of a tube 52, gear drive 53 and motor 54 and to avoid the use of slip-rings the probe is prevented from rotating about its own axis by means of a chain 62 coacting with a sprocket 63 attached to the probe support 58 and with a sprocket 61 fixed to the fixed tube 55. In the operation of this embodiment the assembly as a whole moves to produce the other scan component. When, as shown, a single probe is employed readings are only taken during alternate half-revolutions. Two probes, one at each end of arm 57, may be employed, however, and readings again taken during alternate half-revolutions.