GB2153788A

GB2153788A - Handling system for inspection equipment

Info

Publication number: GB2153788A
Application number: GB08431122A
Authority: GB
Inventors: Derek Bradstreet
Original assignee: UK Atomic Energy Authority
Current assignee: UK Atomic Energy Authority
Priority date: 1984-02-07
Filing date: 1984-12-10
Publication date: 1985-08-29
Also published as: GB8431122D0; GB2153788B; FR2563760A1; GB8403158D0

Abstract

A handling system for inspection equipment, such as used in the inspection of the interior of heat exchange tubes, has an articulated rack assembly (3) to the leading rack (2') of which the inspection probe (1) is connected. The racks (2, 2') are designed to be formed into a coil of polygonal configuration (eg square) for storage on a reel (6) which also serves to store coiled cable (20) connecting the probe (1) to measuring and data handling equipment. The probe (1) is positioned in the tube bore by paying out the racks (2, 2') from the coil by means of a pinion driven by stepper motor (18) and an encoder (19) is driven by the racks (2, 2') to provide an indication of probe position. <IMAGE>

Description

SPECIFICATION Handling system for inspection equipment This invention relates to a handling system for use in positioning an inspection device within a bore.

There exist requirements for the movement into and out of an operating region and when in the operating region the variation in position within that region, of inspection equipment for the condition and quality assurance of materials and joints etc between materials in inaccessible positions, necessitating the remote control of the handling system of the inspection equipment. An example is the requirement for inspection within a tube by an ultrasonic probe for detection of possible defects, such as thinning or surface damage, the probe necessarily needing to be moved along within the tube to cause it to register in turn with relevant positions within the tube.Where the tube is vertical and forms one of a very large number of similar tubes constituting, for example a heat exchanger, it will be appreciated that the inspection of tubes must be done quickly, and the results must be presented and stored in a logical manner which permits the information being readily retrievable at a later date, with assurance that information from the scanning of say one tube out of many thousands can be readily and accurately retrieved. Furthermore, the ability to compare features of tubes found in inspections which may have been made several years apart is an important advantage. This relies on the ability to position the probe with high accuracy and repeatability.

It is the object of the present invention to provide a handling system for inspection equipment which possesses, inter alia, the desirable features set forth in the preceding paragraph.

According to the present invention there is provided a handling system for use in positioning an inspection device within a bore, comprising a storage frame, a plurality of elongate members which are pivotally connected endwise to one another so that adjacent elongate members can be angularly related to one another with the elongate members collectively formed into a compact storage configuration supported on the storage frame, means for paying out said elongate members from the stored configuration so that the elongate members so paid out can align longitudinally with each other, and a position indicator responsive to the extent to which the elongate members have been paid out.

According to one embodiment of the invention, the handling system includes an articulated rack to one end of which the inspection equipment is connected, driving means operable stepwise and connected to a pinion engaged with the said rack, another pinion engaged with the rack and adjoining the first-named pinion, the second pinion being connected to a position indicator, and a pivotally mounted frame on which the articulated rack can be stored together with a cable extending from the inspection equipment to measuring, recording, and/or data storage/retrieval equipment.

The operation of the drive means may be under the control of a computer programmed to follow a desirable inspection procedure in combination with readings of the said position indicator.

Various other desirable attributes of the handling system will be evident to those familiar with the art from the ensuing description of a particular embodiment the construction of which is illustrated in the accompanying diagrammatic drawings, wherein:- Figure 1 is a front elevation of a handling system for inspection equipment, Figure 2 is a side view of a detail, and Figure 3 is a detached plan view of Figure 2.

Figure 4 is a side view of another detail, and Figure 5 is a plan view of Figure 4.

Figure 6 is a side view of a further detail, Figure 7 is an end view of Figure 6, and Figure 8 is a rear view of Figure 6.

Figures 9-12 are sequence views to show operating stages, and Figure 13 is a side view in section of a typical subject for inspection.

Referring firstly to Figure 1, this illustrates the mechanical features of handling equipment which has the ability to control the disposition and displacement of an item of inspection equipment, in the present example, an ultrasonic probe head 1.

This is suspended from one end member 2' of a plurality of members 2, constituting an articulated rack assembly 3, see also Figures 2 and 3. The rack members 2, 2' are of unequal length and are pivotally joined to one another with tongue and groove engagement 4 (see Figure 3) so that they can be folded into square configuration, as shown in Figure 2, and supported within a Y groove 5 on a framework 6, (see Figures 4 and 5) pivoted to a stand 7 (Figure 1) and having a central pulley 8 on which a rope 9 carrying a weight 10 can be wound.

The framework 6 also has a limb 11 on each framework leg 12 (see Figure 5) and disposed adjoining the means constituting the Y groove 5.

The positioning of the probe head 1 is accomplished by raising and lowering under control from the driving assembly 13 shown in Figures 6, 7, 8. A base plate 14 mounted on the stand 7 carries a guide 15 which positions a respective rack member 2 or 2' so that the teeth of the relevant rack member are engaged with the teeth of a small pinion wheel 16 and also, at an adjoining position, with the teeth of a larger pinion wheel 17. The pinion 16 is driven by a stepping motor 18 which thus advances the rack member 2 or 2' by a small amount of each step, in either direction as desired. The pinion 17 is connected to an absolute optical encoder 19 which functions, together with electronic circuitry, to give an accurate position indication of the probe head 1 relative to a fixed datum position.

There can be feedback loop from the encoder 19 for controlling the operation of the motor 18. A cable 20 from the probe head 1 is carried via a loop 21 with pulley 22 and balance weight 23 over a pulley 24 secured to the base plate 14 and the remainder of the cable is stored on the framework 6 over the limbs 11, the loop 21 allowing for variation in storage diameter compared with the articu lated rack. The cable passes to electronic circuitry, not shown but of conventional components and conventional assembly, for measuring, presenting, recording and storing of the A computer can be employed, programmed to establish a pattern of operation for a particular purpose. One such purpose is the inspection of the properties of heat exchanger tubes at positions considerably remote from the upper tube plate and otherwise inaccessible. An example of such a heat exchanger is an evaporator employed in a fast nuclear reactor where water flows in the tubes and sodium flows over the tubes. Figure 13 shows diagrammatically the situation, the tube plate being designated 25, one of the many tubes 26, and the tube to tube plate weld point 27. The probe head 1 is applied from above to and positioned in, the relevant tube by raising or lowering as appropriate to view the tube at different levels in turn.

Figures 9-12 show in turn how the framework 6 appears for various positions of the rack member 2, 2' during lowering. The positions shown in Figure 9 and 12 give datums, it being noticed in each case that legs 12 are horizontal that a rack joint is level with the top of the guide 15, and that the framework has turned through 90. This situation can be employed in conjunction with the encoder 19.

Claims

1. A handling system for use in positioning an inspection device within a bore, comprising a storage frame, a plurality of elongate members which are pivotally connected endwise to one another so that adjacent elongate members can be angularly related to one another with the elongate members coliectively formed into a compact storage configuration supported on the storage frame, means for paying out said elongate members from the stored configuration so that the elongate members so paid out can align longitudinally with each other, and a position indicator responsive to the extend to which the elongate members have been paid out.

2. A handling system as claimed in claim 1 in which said elongate members are engaged so that, in the compact storage configuration, they collectively form a coil of polygonal configuration.

3. A handling system as claimed in Claim 1 or 2 in which each elongate member comprises a toothed rack and in which said paying out means comprises stepwise operable driving means including a pinion for engagement with successive ones of the elongate members.

4. A handling system as claimed in Claim 3 in which the position indicator is operable by a pinion engageable with and driven by said elongate members.

5. A handling system as claimed in any one of Claims 1-4 in which the lengths of the elongate members diminish from the leading member to the trailing member.

6. A handling system as claimed in any one of Claims 1-5 in which the storage frame is rotatable.

7. A handling system as claimed in any one of Claims 1-6 in which the paying out means is operable to displace the elongate members in the reverse direction.

8. A handling system as claimed in any one of Claims 1 to 7 in which the storage frame also serves to store cable for electricaily connecting an inspection device connected to the leading elongate member to measuring, recording and/or data storage/retrieval equipment.

9. A handling system as claimed in any one of Claims 1-8 in which guide means is associated with the paying out means so as to locate each elongate member in a predetermined orientation while engaged with the paying out means and in which the storage frame is rotatable and so positioned that, as it is paid out from the storage frame, each elongate member is substantially aligned with the preceding elongate member which will be located in said predetermined orientation by the guide means.

10. A handling system for use in positioning an inspection device within a bore, substantially as hereinbefore described with reference to, and as shown in, the accompanying drawings.