GB2105845A

GB2105845A - Centering support means for ultrasonic inspection apparatus

Info

Publication number: GB2105845A
Application number: GB08122966A
Authority: GB
Inventors: Frank Iddon Buckley; Raymond Williams
Original assignee: UK Atomic Energy Authority
Current assignee: UK Atomic Energy Authority
Priority date: 1981-07-24
Filing date: 1981-07-24
Publication date: 1983-03-30

Abstract

A centering support means for a rod or bar of non-uniform profile whilst it is advanced axially through the support means comprises multiple support rollers (10) which can be urged to common radial positions relative to a reference axis by the positioning of a resiliently loaded master member (17) acting on the rollers. A pair of such support means can be located adjacent to and on each side of a rotatable ultrasonic inspection head to inspect profiled rods used in nuclear reactors. The rollers (10) may be movable in slots (14) or they may be pivotally mounted (Figure 3, not shown). <IMAGE>

Description

SPECIFICATION Bar centering means This invention relates to centering means. This invention is primarily concerned with problems arising with the use of a known ultrasonic bar or rod inspection apparatus.

The known apparatus above referred to comprises an ultrasonic inspection head rotatable on a fixed axis and having support means on both sides of the head to provide centering support for a rod or bar whilst it is caused to move axially through the head for inspection. A requirement of this apparatus is that the support means should at all times centre the rod or bar being inspected precisely in passage through the head. No problems arise with construction of apparatus to inspect rods and bars of uniform profile as the rods or bars can be centered by simple entry and axis supports. Problems do arise with the use of the known apparatus to inspect bars of non-uniform profile as simple exit and entry supports may not be able to hold the rods or bars precisely centred at all times.

In providing a solution to this problem the present invention provides centering support means for a rod or a bar of non-uniform profile to retain it on a fixed axis as it is advanced axially through the support means: said support means comprising multiple support members urgable to common radial positions relative to a reference axis by the positioning of a resiliently loaded master member acting on said support members.

By using a pair of support means according to the invention located adjacent to and on each side of a rotatable ultrasonic inspection head it becomes possible to inspect the profiled rods used in nuclear reactors which may typically be ten metres long and include lengths of uniform profile interrupted by recessed lengths, tapered lengths, castellated lengths, and projecting parts.

The multiple support members are preferably in the form of rollers. The master member may then have a conical face to determine the common radial positions of the rollers or the rollers may be carried at the hinge points of toggle arms with one of the toggle arms pivotable about fixed axes and the other of the toggle arms pivoted about axes carried on the master member.

Two centering support means according to the present invention will now be described with reference to the accompanying drawing in which: Figure 7 is a section elevation (on line I-I of Figure 2) of one form support means; illustrating both inlet (marked "I") and exit (marked "E") support means; Figure 2 is a section on the line ll-ll of Figure 1; and Figure 3 is a sectional elevation of the other form of support means with only the inlet end support means shown.

In Figures 1 and 2 there are shown three equispaced support rollers 10 carried in a cage 11 having a bore 12 through which a bar or rod of non-uniform profile to be inspected can be moved axially in the direction indicated by arrow 21. The rollers 10 are carried on axles 13 movable radially in inclined slots 14 in the cage 11.

The cage 11 is circumferentially supported on a body tube 15 at 16. The body tube hasslidable in zit a master member 17 urged buy a compression spring 18. The member 17 has three forks 19 defining a conical face 20 which acts on the axles 13 and hence acts also on the rollers 10 to urge them radially inwards.

(It should be mentioned that the drawings do not show true sections). For example in Figure 1 the upper part of member 17 is shown in the "fully extended" position to urge the rollers 10 into the radially innermost position - see also the uppermost roller 10 in Figure 2 - and the lower part of number 17 is shown in the "fully withdrawn" position to accommodate the rollers 10 in the radially outermost position - see also the lower rollers to Figure 2).

The parts in ghost outline relate to the rotatable ultrasonic inspection head which is known and therefore not described.

In Figure 3 the centering support means has three support rollers carried at the hinge pivots 31 of toggle arms 32,33. The arm 33 is pivotable about a fixed axis 34 and the arm 32 is pivotable about an axis 35 carried on a master member 36.

The member 36 has bearing pads 37 carried at the periphery of a flange 38. The flange 38 reacts with a compression spring 39 in a recess of a body tube 40.

The tube 40 has bearing pads 41 for the tail-end of the member 36 has a flange 42 for association with an ultrasonic measuring head shown in ghost outline.

The master member 36 defines a bore 43 along which a member to be inspected can be made to pass.

As with Figure 1, a true section is not shown, the upper half shows the master member advanced and the lower half shows the master member withdrawn.

It is seen in both embodiments that the rollers are urged to common radial positions relative to the axis of the bore 12 (Figure 1) or bore 43 (Figure 3) by the action of the compression springs acting on the respective master member. Thus, as a rod or bar of non-uniform profile passes along the bore, the rollers 10 (Figure 1) or 30 (Figure 3) hold the rod or bar accurately on the axis of the bore.

CLAIMS (Filed 9 July 1982) 1. Centering support means for a rod or bar of non-uniform profile to retain it on a fixed axis as it is advanced axially through the support means: said support means comprising multiple support members urgable to common radial positions relative to a reference axis by the positioning of a resiliently loaded master member acting on said support members.

2. Support means as claimed in claim 1 in which the support members are rollers and the master number has a conical face to determine the common radial positions of the rollers.

3. Support means as claimed in claim 1 in which the support members are rollers and the rollers are carried at the hinge points of toggle arm pairs with one of the toggle arms of each pair pivotable about a

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Bar centering means This invention relates to centering means. This invention is primarily concerned with problems arising with the use of a known ultrasonic bar or rod inspection apparatus. The known apparatus above referred to comprises an ultrasonic inspection head rotatable on a fixed axis and having support means on both sides of the head to provide centering support for a rod or bar whilst it is caused to move axially through the head for inspection. A requirement of this apparatus is that the support means should at all times centre the rod or bar being inspected precisely in passage through the head. No problems arise with construction of apparatus to inspect rods and bars of uniform profile as the rods or bars can be centered by simple entry and axis supports. Problems do arise with the use of the known apparatus to inspect bars of non-uniform profile as simple exit and entry supports may not be able to hold the rods or bars precisely centred at all times. In providing a solution to this problem the present invention provides centering support means for a rod or a bar of non-uniform profile to retain it on a fixed axis as it is advanced axially through the support means: said support means comprising multiple support members urgable to common radial positions relative to a reference axis by the positioning of a resiliently loaded master member acting on said support members. By using a pair of support means according to the invention located adjacent to and on each side of a rotatable ultrasonic inspection head it becomes possible to inspect the profiled rods used in nuclear reactors which may typically be ten metres long and include lengths of uniform profile interrupted by recessed lengths, tapered lengths, castellated lengths, and projecting parts. The multiple support members are preferably in the form of rollers. The master member may then have a conical face to determine the common radial positions of the rollers or the rollers may be carried at the hinge points of toggle arms with one of the toggle arms pivotable about fixed axes and the other of the toggle arms pivoted about axes carried on the master member. Two centering support means according to the present invention will now be described with reference to the accompanying drawing in which: Figure 7 is a section elevation (on line I-I of Figure 2) of one form support means; illustrating both inlet (marked "I") and exit (marked "E") support means; Figure 2 is a section on the line ll-ll of Figure 1; and Figure 3 is a sectional elevation of the other form of support means with only the inlet end support means shown. In Figures 1 and 2 there are shown three equispaced support rollers 10 carried in a cage 11 having a bore 12 through which a bar or rod of non-uniform profile to be inspected can be moved axially in the direction indicated by arrow 21. The rollers 10 are carried on axles 13 movable radially in inclined slots 14 in the cage 11. The cage 11 is circumferentially supported on a body tube 15 at 16. The body tube hasslidable in zit a master member 17 urged buy a compression spring 18. The member 17 has three forks 19 defining a conical face 20 which acts on the axles 13 and hence acts also on the rollers 10 to urge them radially inwards. (It should be mentioned that the drawings do not show true sections). For example in Figure 1 the upper part of member 17 is shown in the "fully extended" position to urge the rollers 10 into the radially innermost position - see also the uppermost roller 10 in Figure 2 - and the lower part of number 17 is shown in the "fully withdrawn" position to accommodate the rollers 10 in the radially outermost position - see also the lower rollers to Figure 2). The parts in ghost outline relate to the rotatable ultrasonic inspection head which is known and therefore not described. In Figure 3 the centering support means has three support rollers carried at the hinge pivots 31 of toggle arms 32,33. The arm 33 is pivotable about a fixed axis 34 and the arm 32 is pivotable about an axis 35 carried on a master member 36. The member 36 has bearing pads 37 carried at the periphery of a flange 38. The flange 38 reacts with a compression spring 39 in a recess of a body tube 40. The tube 40 has bearing pads 41 for the tail-end of the member 36 has a flange 42 for association with an ultrasonic measuring head shown in ghost outline. The master member 36 defines a bore 43 along which a member to be inspected can be made to pass. As with Figure 1, a true section is not shown, the upper half shows the master member advanced and the lower half shows the master member withdrawn. It is seen in both embodiments that the rollers are urged to common radial positions relative to the axis of the bore 12 (Figure 1) or bore 43 (Figure 3) by the action of the compression springs acting on the respective master member. Thus, as a rod or bar of non-uniform profile passes along the bore, the rollers 10 (Figure 1) or 30 (Figure 3) hold the rod or bar accurately on the axis of the bore. CLAIMS (Filed 9 July 1982)

1. Centering support means for a rod or bar of non-uniform profile to retain it on a fixed axis as it is advanced axially through the support means: said support means comprising multiple support members urgable to common radial positions relative to a reference axis by the positioning of a resiliently loaded master member acting on said support members.

3. Support means as claimed in claim 1 in which the support members are rollers and the rollers are carried at the hinge points of toggle arm pairs with one of the toggle arms of each pair pivotable about a respective fixed axis and the other one of the toggle arms of each pair pivotable about a respective axis carried on the master member.

4. Centering support means substantially as hereinbefore described with reference to either Figures 1 and 2 or Figure 7 of the drawings.

5. Ultrasonic rod or bar inspection apparatus comprising a pair of support means according to any preceding claim located adjacent to and on each side of a rotatable ultrasonic inspection head.