GB2410717A

GB2410717A - A locating tool

Info

Publication number: GB2410717A
Application number: GB0402580A
Authority: GB
Inventors: David Paul Whithorn; Neil Phelps
Original assignee: UK Secretary of State for Defence
Current assignee: UK Secretary of State for Defence
Priority date: 2004-02-06
Filing date: 2004-02-06
Publication date: 2005-08-10
Also published as: GB0402580D0

Abstract

A locating tool (1, fig 1) is described for assisting in the accurate placement and attachment of an article 23 to an engagement location 29A,29B within a confined space of an enclosure, the enclosure having an opening. The tool comprises a body (3, fig 1) and a member (2, fig 1) for supporting an article, wherein the tool is supported within the enclosure and the support member is moveable relative to the engagement location while maintaining the article at a desired orientation. The tool further comprises means to limit lateral movement of the support member, thereby enabling the accurate placement and attachment of the article to the engagement location. Preferably, the article being attached is a detecting element, such as a Passivated Implanted Planar Silicon (PIPS) detector, and the enclosure is the counting chamber of a spectrometer.

Description

LOCATING TOOL

The present invention relates to a locating tool for use in a confined space.

More particularly, the present invention has been devised to assist in the accurate placement and attachment of an article to an engagement location within a confined space. The locating tool may find use in applications including, but not limited to, various scientific measuring apparatus and instruments.

Within many walks of life, there exists the need to manually and accurately place and attach an article to an engagement location within a confined space. A confined space is herein defined as a space offering limited manual access, possibly coupled with poor or no visibility of the engagement location.

In such a confined space, the article would typically be manually manipulated by the fingers of a person to ensure its accurate placement and attachment to the engagement location. The nature of the confined space - both the limited access and the poor visibility of the engagement location - present problems that hinder the accurate placement and attachment of the article. ë .

Current methods of manual placement and attachment can be time consuming and laborious. There is also a significant risk of the article becoming misaligned during its placement and attachment, with the consequent risk of damage to the article and/or the engagement location. The risk of damage is amplified when the article and/or its component parts are small in size and strength. The means by which the article is attached to the engagement location is likely to be particularly prone to damage. For example: where attachment is by means of a screw-thread arrangement, misalignment may result in crossed or distorted threads; where attachment is by means of a bayonet-lug arrangement, misalignment risks distorted or sheared lugs.

The above problems are exacerbated when there is a need to minimise direct finger contact with the article - for example, to avoid contamination or damage to the article. Any limitation on the parts of the article that the fingers may have contact with will inevitably make accurate placement and attachment of the article more time consuming and difficult.

The aforementioned problems are particularly prevalent in sensitive scientific apparatus, especially that used in measuring and analysis - for example, when attaching or extracting a detecting element to or from the counting chamber of a spectrometer. Spectrometers are used in the detection of radioactive emissions - for example, in detecting emissions of alpha particles or gamma photons. In use, samples of a material are placed within the counting chamber for analysis. Locating the detecting element within the counting chamber of the spectrometer is one example of the known problem of fitting an article inside a confined space. The precise nature of the detecting element differs depending on the type of emission to be detected.

In the case of an alpha spectrometer - used to detect and measure the energy levels of alpha particle emissions - the detecting element is typically adapted : with a threaded profile to enable its attachment to a corresponding threaded .

bore within the counting chamber. The detecting elements have a limited lifespan, meaning that they must be replaced from time to time. With the detecting elements of spectrometers being costly items, it is highly desirable to avoid any damage or contamination that would render the detecting element unusable.

Currently, the attachment of a new detecting element is undertaken by manually manipulating the element by hand. This can be a time-consuming process, as the engagement location is typically out of direct line of sight. For successful attachment, the detecting element must be moved into the correct spatial position relative to the engagement location, and the element must be held at the correct orientation relative to the engagement location. Failure to satisfy these two criteria will impair correct attachment and potentially damage the threaded profile of the detecting element and/or the corresponding threaded bore. The detecting element of a spectrometer is a delicate piece of scientific apparatus. In the case of an alpha spectrometer, the detecting element typically comprises a thin detection window, located on an end face of the element, through which alpha particles may pass. The window is manufactured to be as thin as possible, thereby maximising the detection capability of the spectrometer to low energy alpha particle emissions. To avoid the risk of damage to or contamination of the detecting element, direct contact between the end face of the detecting element and the person should be minimised. The known method of manually manipulating the detecting element risks damage to and/or contamination of the detecting element.

Accordingly there is provided a locating tool for use in a confined space of an enclosure, the enclosure having an opening, the confined space being e--. provided with an internal engagement location, the tool comprising a body and a member for supporting an article, wherein the tool is supported within the enclosure and the support member is moveable relative to the engagement location while maintaining the article at a desired orientation, the tool further :. comprising means to limit lateral movement of the support member, thereby ë.

.: enabling the accurate placement and attachment of the article to the engagement location. The desired orientation is one in which the article is maintained at or close to an alignment that minimises the risk of damage to the engagement location and/or the article during its attachment. The means of limiting the lateral movement of the support member is such that the locus of movement of the support member and of the article it supports encompasses the engagement location during use of the tool. Providing such a limitation on the lateral movement of the support member may assist in the accurate placement and attachment of the article and reduce the time taken to attach the article. Maintaining the article at the desired orientation reduces the likelihood of misalignment of the article and any consequent damage that may occur to the article and/or the engagement location. Furthermore, provision of the support member ensures that direct contact between the article and the fingers of a user of the tool is minimised, thereby reducing the likelihood of damage to and contamination of the article.

Preferably, the support member is rotatably moveable about an axis and is moveable in both of the following senses: i. moveable along the axis of rotation, and ii. laterally moveable relative to the body so as to adjust the location of the axis of rotation.

This aspect of the present invention maximises the degree of controllable movement of the support member, thus assisting in the accurate placement and attachment of the article.

Preferably, the means to support the tool within the enclosure comprises an adjustable member that is moveable towards and away from the body, thereby enabling the tool to be adapted for the size of the confined space and releasably secured within the enclosure. This aspect of the present invention enables the tool to be secured within the enclosure, thereby minimising any undesired movement of the tool during its use and assisting in the accurate placement and attachment of the article. Typically, the adjustable member, . . : when extended, would abut against one or more walls of the enclosure contact between the adjustable member and the one or more walls thereby securing the tool as desired. Advantageously, the adjustable member comprises two substantially parallel plates, each plate being laterally moveable relative to the body. This aspect of the present invention provides an efficient yet effective means of securing the tool within the enclosure.

Typically, the plates would be extendable so as to abut against opposing walls of the enclosure. Conveniently, the plates are in a substantially common plane.

Preferably, each of the plates has at least one elongated penetration that co- operates with the body to assist the lateral movement of the plates. This aspect of the present invention provides a means of limiting the extent of lateral movement of the plates. Conveniently, the means to releasably secure the tool within the enclosure comprises a locking means that extends through each elongated penetration into the body to thereby fix the plates in position.

This aspect of the present invention minimises the risk of any undesired movement of the plates and, consequently, of the tool within the enclosure.

The locking means may include but is not limited to a threaded member, such as a bolt or a screw.

Preferably, the body comprises an opening through which the support member extends, with contact between the support member and the periphery of the opening thereby providing the means of limiting the lateral movement of the support member. This aspect of the present invention provides a simple yet effective means of limiting the degree of lateral movement of the support .

member. .

Preferably, the tool comprises a part that is slidably moveable relative to the body and co-operable with the support member so as, in use, to maintain the article at the desired orientation. This aspect of the present invention enables :. the spatial position of the support member and the article it supports to be .

adjusted relative to the engagement location, whilst reducing the likelihood of misalignment of the article and any consequent damage that may occur.

Advantageously, the body comprises two opposing parallel surfaces that each abut a corresponding face of the slidably moveable part, the part being slidably moveable relative to the opposing parallel surfaces and comprising an aperture through which the support member extends, the support member being slidably moveable along the central axis of the aperture. This aspect of the present invention provides an effective means of maximising the degree of controllable movement of the support member whilst maintaining the article at the desired orientation. The aperture should be sized such that it provides a close slideable fit relative to the support member, thereby ensuring that the support member maintains the article at the desired orientation during use of the tool.

Preferably, the support member comprises anti-slip means to limit sliding of the article relative to the support member. This aspect of the present invention minimises slippage or sliding of the article on the support member which would otherwise hinder the accurate placement and attachment of the article to the engagement location. The anti-slip means may comprise an elastomeric material, such as rubber.

Advantageously, in use the anti-slip means is in contact with at least one of: i. the base of the article, and ii. the periphery of the article.

This aspect of the present invention further assists in minimising slippage or sliding of the article on the support member. ë.. .

Conveniently, the support member comprises a recess for containment of the anti-slip means. The recess may be formed such that it can contain an O-ring made of rubber or another elastomeric material.

: Preferably, the support member comprises a raised wall section that extends .

about the periphery of the article. This aspect of the present invention reduces the likelihood of the article falling from or sliding off the support member during use of the tool. Preferably, the support member is provided with a knurled profile that is accessible to the fingers of a user of the tool.

Provision of the knurled profile will assist the user in manipulating the support member and the article it supports to thereby enable the accurate placement and attachment of the article.

The present invention is now described herein with reference to the accompanying drawings, of which: Figure 1 shows an isometric view of a locating tool as per the present invention.

Figure 2 shows a plan view of the locating tool of Figure 1.

Figure 3 shows a plan view of the split top plate of the locating tool of Figure 1.

Figure 4 shows a plan view of the bottom plate of the locating tool of Figure 1.

Figure 5 shows an isometric view of the support member of the locating tool of Figure 1.

Figure 6 shows a cross section of the support member of Figure 5 through a section A-A.

Figure 7 shows an isometric view of the slide ring of the locating tool of Figure 1.

Figure 8 shows an isometric view of a Passivated Implanted Planar Silicon (PIPS) detecting element of an alpha spectrometer when looking upon an end face of the element.

Figure 9 shows a further isometric view of the detecting element of Figure 8 when looking upon the opposing end face of the element.

Figure 10 shows a cross section of the locating tool of Figure 1 through a section B-B.

Figure 11 shows a partial isometric view of the counting chamber of an alpha Spectrometer ë Figure 12 shows the locating tool in use within the counting chamber of Figure 1 1.

A locating tool 1 (Figure 1) comprises a support member 2 and a body 3. The support member 2 (shown in Figures 5 & 6) comprises a base section 4, a central core 5 and an adjustment knob 6 (Figure 10). The periphery of the base section 4 is circular in plan and defines a raised wall section 7 that extends about the periphery of a flat circular platform 8 (Figures 5 & 6). A recess 9 is formed adjacent to the peripheral wall section 7 and the platform 8.

Anti-slip means in the form of an O-ring 10 (Figures 10 & 12) is located within the recess 9. As indicated in Figures 5 & 6, the central core 5 is smaller in cross section than the base section 4, being formed integral with and extending from the underside of the base section. As shown in Figures 10 & 12, the adjustment knob 6 extends within a cavity 1 1 (Figure 6) provided in the underside of the central core 5. The adjustment knob 6 and the cavity 11 are provided with complimentary threaded profiles 12, thereby enabling the adjustment knob to be secured within the cavity. An adhesive (not shown) may also be employed to assist in preventing the adjustment knob 6 from working loose. The periphery of the adjustment knob 6 is provided with a knurled profile 13 (Figures 10 & 12).

The body 3, as shown particularly in Figures 1 to 4, 7 and 10, is defined by two flat rectangular plates 1 4A, 1 4B (hereinafter collectively referred to as the split top plate 14), two spacers 15, a flat rectangular bottom plate 16, four bolts 17 and a slide ring 18. Two elongated penetrations 19 (Figure 3) are provided within each of the plates 14A, 14B. The bolts 17 extend through the elongated penetrations 19, via corresponding penetrations (not shown) provided in the spacers 151 to be secured into the bottom plate 16. As indicated in Figure 10, the opposing faces of the split top plate 14 and the bottom plate 16 are parallel to each other and provide a sliding fit relative to the flat opposing faces of the slide ring 18. An opening is defined within the : body 3 by apertures 20, 21, 22 that are provided in the split top plate 14, ë.

I. ..: bottom plate 16 and slide ring 18 respectively - see Figures 3, 4, 7 & 10.

When assembled, the central core 5 of the support member 2 extends through the apertures 20, 21, 22 to protrude beneath the underside of the body 3 (Figure 10). With the diameter of the adjustment knob 6 being larger than that of aperture 21, the knob thereby fulfils a secondary function of preventing the support member 2 and the body 3 from becoming detached from each other.

As can be seen from Figures 10 & 12, apertures 20, 21 are larger in size than the diameter of the central core 5. However, the aperture 22 is formed such that it provides a close slidable fit relative to the central core 5 of the support member 2.

The use of the locating tool will now be described: Firstly, a Passivated Implanted Planar Silicon (PIPS) detecting element 23 (as shown particularly in Figures 8 to 10 and 12) is placed upon the base section 4 of the support member 2 such that the outer protruding annular rim 24 of an end face of the detecting element is in contact with the O-ring 10. A thin flat circular detection window 25 (Figure 9) is provided on the end face. The opposing end face (Figure 8) of the element 23 is provided with a threaded member 26 that is adapted for engaging with an engagement location in the form of a threaded bore 27. The threaded bore 27 is provided within an enclosure (Figures 11 & 12) defined by the counting chamber 28 of an alpha spectrometer.

Secondly, the locating tool 1 is placed within the counting chamber 28, being located such that it is vertically supported by shelf sections 29A, 29B. As ^ indicated in Figures 11 & 12, the width of the shelf sections 29A, 29B is comparatively small with respect to the width of the counting chamber 28.

The counting chamber 28 would typically comprise a series (not shown) of such shelf sections located at along various positions within the counting chamber. The region between the shelf sections 29A, 29B and the threaded bore 27 defines a confined space that offers minimal access to a person's fingers. The tool 1 may be adapted for the size of the counting chamber 28 by adjustment of the lateral positions of the plates 14A, 14B (as indicated by arrows C in Figures 2, 3 & 10). The lateral positions of plates 14A, 14B are adjusted by first loosening the bolts 17, so permitting the plates to be moved laterally relative to the body 3. The elongated penetrations 19 provide a means of limiting the extent of lateral movement of the plates- arrows D indicate the maximum extent of lateral movement of the plates. Once the plates 14A, 14B have been appropriately adjusted, the bolts 17 are tightened to act as a locking means to fix the plates into position against the body 3. As shown in Figure 12, in this embodiment of the present invention plates 14A, 14B are adjusted so that an edge of each plate abuts against a wall of the counting chamber 28, thereby minimising the risk of the tool 1 becoming displaced or falling from the shelf sections 29A, 29B when in use (see Figure 12). This ability to adjust the lateral positions of the plates 1 4A, 1 4B relative to the body 3 allows the tool 1 to be adapted for counting chambers of varying sizes, so avoiding the need for using/manufacturing a different tool for each size of counting chamber. As shown in Figure 12, the tool 1 is placed in the counting chamber 28 so that the underside of the split top plate 14 is supported upon the shelf sections 29A, 29B.

Thirdly, a user (not shown) may then grasp the knurled profile 13 of the adjustment knob 6 to adjust the spatial position of the support member 2 and thereby the detecting element 23 - by manipulating the knob 6. The support member 2 is moveable in all of the following senses: a. rotatably moveable about an axis 30 (indicated by arrows E in Figures 10 & 12 - see also Figures 1, 5 & 6); ë a.

b. moveable along the axis 30 (indicated by arrows F in Figures 10 & ace . 12 - see also Figures 1, 5 & 6); and . c. laterally moveable relative to the body 3, the lateral motion being perpendicular to the axis 30 (indicated by arrows G in Figure 2 - see also Figures 1, 5 & 6). t e

A

.. The user manipulates the adjustment knob 6 until the threaded member 26 just engages with the threaded bore 27. The support member 2 may then be rotated about the axis 30 to tighten the detecting element 23 into position.

The O-ring 10 assists in the tightening process by minimising any slipping or sliding of the element 23 relative to the support member 2. Anti-slip means other than the O-ring 10 may be employed to equivalent effect; for example, i) a ring with a rectangular cross section could effectively be located in the recess 9, or ii) segments made of an elastomeric material could be located within either the recess 9 or similar cavities provided within the support member 2. The peripheral wall section 7 of the support member 2 helps to reduce the likelihood of the detecting element 23 falling from or sliding off the support member 2 during use of the tool.

Contact between the central core 5 and the periphery of aperture 20 or 21 provides a means of limiting the lateral movement of the support member 2.

The close slidable fit of the central core 5 relative to and within the aperture 22 of the slide ring 18 assists in enabling movement of the support member in all of senses a-c whilst maintaining the article at a desired orientation. In this embodiment of the present invention, the desired orientation is such that the central axis 31 of the threaded member 26 (Figure 8) remains parallel to the central axis 32 of the threaded bore 27 (Figure 11).

Note that the tool 1 may also be used to assist in the extraction of the detecting element 23. The process of extraction is essentially the reverse of : that described above for attachment of the element 23. ë r ëce a. a. :. ee. ë ë

Claims

What we claim is: 1. A locating tool for use in a confined space of an enclosure, the enclosure having an opening, the confined space being provided with an internal engagement location, the tool comprising a body and a member for supporting an article, wherein the tool is supported within the enclosure and the support member is moveable relative to the engagement location while maintaining the article at a desired orientation, the tool further comprising means to limit lateral movement of the support member, thereby enabling the accurate placement and attachment of the article to the engagement location. ë.e
2. A locating tool as claimed in claim 1, wherein the support member is rotatably moveable about an axis and is moveable in both of the following senses: .

i. moveable along the axis of rotation, and ii. laterally moveable relative to the body so as to adjust the location of the axis of rotation.
3. A locating tool as claimed in either of claim 1 or 2, wherein the means to support the tool within the enclosure comprises an adjustable member that is moveable towards and away from the body, thereby enabling the tool to be adapted for the size of the confined space and releasably secured within the enclosure.
4. A locating tool as claimed in claim 3, wherein the adjustable member comprises two substantially parallel plates, each plate being laterally moveable relative to the body.
5. A locating tool as claimed in claim 4, wherein the plates are in a substantially common plane.
6. A locating tool as claimed in either of claim 4 or 5, wherein each of the plates has at least one elongated penetration that co-operates with the body to assist the lateral movement of the plates.
7. A locating tool as claimed in claim 6, wherein the means to releasably secure the tool within the enclosure comprises a locking means that extends through each elongated penetration into the body to thereby fix the plates in position. :.e . a.
8. A locating tool as claimed in claim 7, wherein the locking means comprises a threaded member. . .
9. A locating tool as claimed in any preceding claim, wherein the body comprises an opening through which the support member extends, with contact between the support member and the periphery of the opening thereby providing the means of limiting the lateral movement of the support member.
10. A locating tool as claimed in any preceding claim, wherein the tool comprises a part that is slidably moveable relative to the body and cooperable with the support member so as, in use, to maintain the article at the desired orientation.
11. A locating tool as claimed in claim 10, wherein the body comprises two opposing parallel surfaces that each abut a corresponding face of the slidably moveable part, the part being slidably moveable relative to the opposing parallel surfaces and comprising an aperture through which the support member extends, the support member being slidably moveable along the central axis of the aperture.
12. A locating tool as claimed in any preceding claim, wherein the support member comprises anti-slip means to limit sliding of the article relative to the support member.
13. A locating tool as claimed in claim 12, wherein in use the anti-slip means is in contact with at least one of: i. the base of the article, and ii. the periphery of the article.
14. A locating tool as claimed in either of claim 12 or 13, wherein the support member comprises a recess for containment of the anti-slip e.

c means. e..
15. A locating tool as claimed in any preceding claim, wherein the support .

member comprises a raised wall section that extends about the : . periphery of the article. . .
16. A locating tool as claimed in any preceding claim, wherein the support member is provided with a knurled profile that is accessible to the fingers of a user of the tool.
17. A locating tool as claimed in any preceding claim, wherein the enclosure is the counting chamber of a spectrometer and the article is a detecting element of the spectrometer.
18. A locating tool as claimed in claim 17, wherein the spectrometer is an alpha spectrometer.
19. A locating tool as claimed in claim 18, wherein the detecting element is a Passivated Implanted Planar Silicon (PIPS) detector.
20. A locating tool substantially as described herein with reference to the accompanying drawings. :.. ë - .. .e . .. :. a a . . ë