GB2378992A

GB2378992A - Security devices and lock shackle protectors

Info

Publication number: GB2378992A
Application number: GB0114459A
Authority: GB
Inventors: Harry Mchugh
Original assignee: Smith Flow Control Ltd
Current assignee: Smith Flow Control Ltd
Priority date: 2001-06-14
Filing date: 2001-06-14
Publication date: 2003-02-26
Also published as: GB0206160D0; GB0114459D0

Abstract

A security device for a connection having a pair of mating flanges 12 bolted together, such as a pipeline connector, is in the form of a strap adapted to encircle the connection. The strap comprises a plurality of links 14,15 pivoted together, each link having a base section to overlie the periphery of the connection, and a pair of side plates 30 depending from opposed sides of the base section. A security connector 17 is arranged to secure together the two end links 15 of the strap so that in use the side plates 30 extend over the outwardly directed faces of the flanges 12 and so resist removal of the strap from the connection and also resist access to the bolts making up the connection. The security connector 17 may be a conventional padlock, in which case a guard for the shackle 18 of the padlock may be provided, to restrict access to that shackle.

Description

SECURITY DEVICES AND LOCK SHACKLE PROTECTORS This invention relates to a security device for a connection made up from a pair of mating flanges bolted together. Further, this invention relates to a protector for a lock mechanism which may be used in conjunction with the security device aforesaid.

In the many industrial processing plants and installations where fluids are transported along pipelines, there is a demand for greater operating security and connection integrity in an attempt to guard against accidental, negligent or even wilful breaching of the pressure envelope. A particular area where there is a known problem concerns connections between pipeline sections, or between a pipeline and some other component such as a valve or vessel. Such connections are frequently made up by providing on the two components to be connected respective flanges which are bolted together by means of a ring of bolts extending through aligned bores in the two flanges, possibly with a gasket material between the mating flanges.

Hitherto, there has been no easy and convenient way of securing such a bolted flanged connection against unauthorised or inadvertent release. For example, it would be possible to wire together all of the bolt heads and also the nuts, such as is employed in the aircraft industry, but such a solution offers only a very low level of security and at best may give an indication of whether a connection has been tampered with. Moreover, wiring together all of the bolts in this way is very time consuming and so would not readily be adopted. An alternative is to use security nuts and bolts, such as those having nonhexagonal cross-sections, but then there will be no immediate indication of whether a connection has been tampered with. Further, only a very limited

number of different head forms can be used in any one installation. There has also been a proposal to secure one bolt of the ring thereof against unauthorised removal, this proposal utilising a U-shaped clamp which fits over both the head and threaded end of a bolt, a lock mechanism securing the clamp against unauthorised removal. Though this may offer some degree of security, only one bolt of a connection can in practice be protected and this would not ensure pressure envelope integrity. It would be unrealistic to protect all of the bolts in this way, in view of the large numbers of components, locks, keys and so on which would then be required.

The present invention aims at providing a soiution to the problem of securing a flanged connection in a quick and easy manner, but which gives a reasonably high degree of security and acts as visual and physical deterrent to breaching the pressure envelope.

According to one aspect of the present invention, there is provided a security device for a connection having a pair of mating flanges bolted together, which device is in the form of a strap adapted to encircle the connection, said strap comprising a plurality of links pivoted together, each said link having a base section and a pair of side plates depending from opposed sides of the base section, and there being a security connector to secure together the two ends of the strap, whereby in use the strap is passed around the connection so that the base section of each link overlies the periphery of the flanges making up the connection and the side plates extend over the outwardly-directed faces of the flanges, the security connector being used to secure together the ends of the strap whereby the side plates resist removal of the strap from the connection and also restrict access to bolts making up the connection.

It will be appreciated that with the device of the present invention, a strap made up from a plurality of links is configured to encircle the connection to be protected, the links having end side plates which overlie the outwardly-directed faces of the flanges of the connection, so as to restrict access to the bolts making up the connection. Once fitted thus, the device prevents release of the bolts making up that connection. It is a relatively easy matter to flex the strap around the mating flanges and then secure together the two ends of the strap, for example with a padlock or combination lock. As a consequence, a plant operator may deploy such security devices to protect all critical flanged connections in an installation. The protection may be enhanced by utilising an appropriate keying regime-for example, permitting the same key to open a number of locks and so release a number of the devices, or having an individual lock requiring a unique key for each such device deployed in the installation, or interfacing with interlocks or other pressure control devices..

Further, if a device is removed in an unauthorised manner, such as by breaking or cutting through one or more links or the lock, the device cannot properly be replaced, so making the abuse self-evident on inspection.

A preferred form of the security device of this invention has a strap which comprises a plurality of similar main links pivoted together and a pair of end links disposed one on each end of the strap and adapted to permit their connection together by means of the security connector. Depending upon the profile of the side plates and the radius of curvature about which the strap must be formed in order to encircle a flange, it may be advantageous to employ one or more intermediate links between each pair of main links, in order to avoid the possibility of the side plates of adjacent main links colliding with each other.

The likelihood of this problem occurring can be minimised by appropriate profiling of the side plates-for example, each such side plate may be made of generally triangular form, with the apex of the triangular form remote from the base section of the associated link.

Conveniently, the base section of each link is of generally rectangular shape, in plan. The length of each such base section should be slightly greater than the overall length of the bolts used to make up the flanged connection, so that the side plates of the links may embrace the head and opposed end of each bolt.

Preferabiy, each main iink is provided along one edge with a pivot pin and along the opposed long edge with a receptor for the pivot pin of an adjacent link, whereby the interconnected links may pivot with respect to each other, about the axes of the pins. In such a case, each receptor may be in the form of a channel defining a re-entrant slot, each pin being of an appropriate cross-sectional shape such that the pin may be engaged with the slot and disengaged therefrom when the strap is given a reverse curvature, but once engaged and the strap is then moved to a flanged connection embracing configuration, the links are locked togethe. against relative separation. For example, each pin may be of generally circular cross-sectional shape but having a flat formed therealong, the width of the entrance to the re-entrant slot being substantially equal to the cross-sectional width of the pin across its flat.

With such a configuration, the flat on the pin preferably is disposed so that when there is an obtuse angle between the external surfaces of the base sections of the two links being interconnected, the pin may enter the re-entrant slot or leave that slot.

Each of the two end links (when provided) may have an outwardlyprojecting lug having a hole formed therein, whereby the end links may be secured together by a security connector which has a locking member passing through the aligned holes in the respective lugs. For example, a key-operated padlock or a combination lock may be employed, or indeed some other locking device having a member adapted to pass through the aligned holes in the lugs.

A common form of key-operated padlock or combination lock has a lock body and a U-shaped shackle having first and second legs with one end of the first leg being mounted on the body for movement between a locked position where the corresponding end of the second leg of the shackle is received in an opening in the lock body, and a free position where access may be had to said corresponding end. In order to give such a lock mechanism usefulness for a wide range of applications, the two legs of the staple may be significantly longer than are required for a given use, such as the interconnection of the lugs of the two end links of the security device of this invention as described above. In this case, unless a relatively high strength, high security padlock or combination lock is employed, it may be relatively easy to force open the lock, with a suitable lever, or quickly to cut through the shackle with a hacksaw or boltcropper.

Though a high strength, high security padlock or combination lock could be employed with the security device of this invention, such locks are very expensive and a plant operator may be reluctant to spend a very large sum of money on deploying a significant number of high strength lock mechanisms of this kind. In an attempt to solve this problem, a second aspect of the present invention provides a protector for a lock mechanism as described above, which

protector comprises first and second parts defining respective channels for receiving the first and second legs of the shackle, the first and second parts being provided with interlocking means configured to permit the interconnection thereof by relative sliding movement along the length of the channels so that the channels mate to define a chamber for reception of the shackle, whereby the protector may be fitted to the shackle when in the free position but after the shackle has been passed through a component to be secured by the lock mechanism, and after the two parts have been interconnected by relative sliding movement thereof, the protector is secured against removal from the shackle by moving the shackle to its iocked position.

The lock protector for a lock mechanism as described above greatly reduces access to the shackle of the lock mechanism and so reduces the vulnerability of the lock mechanism to attack. The protector may be configured to enclose a portion of the lock body to which the shackle is mounted, as well as the greater part of the shackle itself, so restricting access to that shackle for example with a lever to force open the lock, or bolt croppers to cut through the shackle. In this way, relatively low cost lock mechanisms may be employed while still giving a high degree of security against unauthorised opening.

The interlocking means may comprise a pin on the first part and projecting from a surface thereof in a direction parallel to the length of the channel therein, the second part having a bore in which said pin is received when the two parts are joined together. Preferably, the first part has a pair of similar pins disposed one to each side of the channel therein and extending in the same direction parallel to the length of the channel, the second part having

a corresponding pair of bores in which the pins are received when the two parts are joined together.

The channel in the second part may be provided with an abutment which prevents the engagement of that part with the second leg of the shackle other than by relative sliding movement along the length of the second leg of the shackle, from its free end. By contrast, the first part may be arranged to engage the first leg of the shackle by lateral movement, to enter the first leg into the channel of the first part.

By way of example only, one specific embodiment of security device for a connection having a pair of mating flanges bolted together and also one specific embodiment of lock mechanism protector, both constructed and arranged in accordance with aspects of the present invention, will now be described in detail, reference being made to the accompanying drawings, in which :- Figure 1 is a isometric view of the embodiment of security device, fitted to a flanged connection; Figure 2 is an internal view of three of the main links of the security device of Figure 1, coupled together; Figure 3 is an isometric view of one of the main links, showing its pivot pin; Figure 4 is an isometric view of the embodiment of shackle protector, fitted to the shackle of a key-operated padlock ; Figure 5 is a diagrammatic axial sectional view through the assembly of protector and lock of Figure 4;

Figure 6 is an isometric view of the protector of Figure 4, but with the second part of the protector removed from both the lock shackle and the first part of the protector; and Figure 7 is an isometric view of the protector wholly removed from a lock mechanism and with its two parts partially separated.

Referring initially to Figures 1 to 3, there is shown the embodiment of security device of this invention, with Figure 1 showing that device fitted to a connection between two pipes 10 and 11 provided with respective abutting flanges 12, the flanges being connected together by means of nuts and bolts 13 spaced around a common pitch-circie on the flanges. Such bolted and flanged connections are extremely well known in various industries and will not be described in further detail here.

The security device comprises a plurality of individual main links 14 pivoted together so as to form a flexible strap, there being two end links 15 at the two ends of the strap and provided with respective lugs 16 by means of which the two ends of the strap may be joined together to form a continuous strap encircling the flanged connection. In this embodiment, each of the two lugs 16 is provided with a through-bore, such that a padlock 17 may have its Ushaped shackle 18 passed through the two aligned bores. In this way, when the shackle 18 is locked to the main body of the padlock, the two end links 15 of the security device are restrained against separation, so maintaining the strap as an essentially endless series of interconnected links.

Each main link 14 (Figures 2 and 3) has a base section 20 of generally rectangular shape, when viewed in plan, a respective pivot pin 21 being disposed along one long edge and on the opposed long edge there is a

receptor 22 for the pivot pin 21 of an adjacent link. Each receptor 22 is of a reentrant channel-shape, with a slot 23 opening into a generally circular channel 24, of the same diameter as that of the pivot pin 21.

As best seen in Figure 3, each pivot pin 21 is formed with a flat 25 extending therealong, the width of the slot 23 corresponding to the crosssectional dimension of the pivot pin measured across the flat 25, whereby appropriate alignment of the pin of one main link with the slot 23 of another link allows the pin 21 to move into the channel 24 of the other link. Then, by turning relatively the two links about the axis of the pivot pin 21, the pivot pin will remain captive within the channel, so interconnecting the two links.

The flat 25 on each link pivot pin should be disposed such that two links may be interconnected only when there is an obtuse angle between the external surfaces 26 of the base sections 20 of the two links. Then, on moving the links to the relative disposition shown in Figure 1, the links will be interconnected and held against separation.

As best seen in Figure 3, the pivot pin 21 extends between a pair of bosses 27 of rounded profile. To each side of the receptor 22 on the opposed long edge of each link, there is a groove 28 having a similar radius of curvature to that of the outer surfaces of the bosses 27, whereby when two links are interconnected, the bosses 27 run in the groove 28 and so resist relative twisting of the links, about an axis perpendicular to the pivot pin axis.

Each of the links 14 is provided with a pair of side plates 30, depending one from each end edge 31 respectively of each link. Each such side plate 30 is generally of triangular form, whereby a strap made up from a plurality of

interconnected links 14 may take up a relatively small radius of curvature, without the side plates 30 impacting one another.

Each link 14,15 conveniently may be manufactured by a casting technique, for example from stainless steel. The base section 20 of each such link may be formed with a plurality of ventilation slots 32, to prevent fluid collecting in a lowermost part of the strap when in use, and so to minimise the likelihood of corrosion either of the links or of the flanges protected by way of the security device. The slots 32 also allow visual inspection of the flanges and seals of the connection without removal of the security device.

As shown in Figure 1, when the device is in use the side plates 30 of the links 14 and 15 project generally radially inwardly from the outer periphery of the flanges of the protected connection. The side plates thus overlie the ends of the nuts and bolts 13 used to make up the flanged connection. In this way, access to those nuts and bolts is restricted by the side plates so preventing the release of the connection until the padlock 17 has been released and the shackle removed from the lugs 16, so freeing the end links 15 and permitting removal of the strap from the flanged connection.

In order to ensure a snug fit of the strap around a flanged connection to be protected, a strap may include one or more special links having a different circumferential length (that is, between its long edges) as compared to the majority of the main links 14. Such special links are shown at 34 but, apart from their different circumferential extent, those special links correspond in form and function to the main links 14 described above.

As can be seen from Figure 1, the padlock 17 and its shackle 18 are relatively exposed, when used to secure together the lugs 16 of the two end

links 15. In order to provide better security and reduce the likelihood of such a padlock being forced or cut open, a shackle protector as shown in Figures 4 to 7 may be employed. Such a shackle protector comprises first and second parts 40 and 41 which are configured for interlocking with each other so as to surround the greater part of a shackle 18 of a padlock 17 or a similar combination lock. The first part 40 of the shackle protector defines a channel 42 in which is received a first leg 43 of the shackle 18, that leg being pivotally mounted at its one end (that is, its end remote from the U-shaped base portion 45 of the shackle 18) to the padlock body 46. At the upper end of the first part 40, there is provided a laterally-projecting shoulder 47 on each side of the channel 42, and from each shoulder 47 there projects a respective interlocking pin 48, extending parallel to the length of the channel 42.

The second part 41 of the shackle protector is arranged to co-operate with the first part and also defines a channel 50, which mates with channel 42 when the two parts are interconnected, to form a chamber for reception of the shackle. To that end, the second part 41 is formed at its upper end with a rebate 51, on each side of its channel 50, a respective bore 52 being provided into the second part from each rebate, for receiving the corresponding interconnecting pin 48 of the first part 40. Thus, by virtue of the pins 48 and bores 52, the first and second parts may be interconnected solely by way of relative sliding movement along the length of pins 48 and so parallel to the length of the two channels 42 and 50 and also of the legs of a shackle to be protected.

The upper end of the protector may be profiled to suit the component to be locked by the padlock 17. In the illustrated embodiment, the upper end is

provided with an outwardly-flared wall 53, which has aligned recesses 54 adjacent the central region of the base portion 45 of the U-shaped shackle, to accommodate the lugs 16 of the end links 15 of the security device of Figures 1 to 3. Further, the lower end of the shackle protector is counter-bored at 55, to receive the end portion of the lock body 46. However, both of these profiles may be adapted to suit a particular lock and application.

Optionally, there may be provided an abutment 56 extending across the channel 50 in the second part 41, whereby that second part may be engaged with the second leg 57 of the shackle only by sliding movement with respect to the length of that second ieg.

To use the shackle protector of Figures 4 to 7, the padlock 17 is released by a key (not shown) so freeing a mechanism (also not shown) within the padlock body 46 and permitting the shackle 18 to move away from the body 46, by a limited amount. When freed in this way, the one end 44 of the first leg 43 remains captive in the body 46, but the one end 58 of the second leg 57 of the shackle comes free of the body 46, so permitting the shackle to be pivoted about the axis of the first leg 43, moving the second leg wholly clear of the body.

The second leg 57 may then be passed through a component to be locked, such as the lugs 16 of the end links 15 of the security device of Figures 1 to 3. Thereafter, the first part 40 of the shackle protector may be moved to have its channel 42 embrace the first leg 43 of the shackle, with the lugs 16 being located partly within the recesses 54 in upper wall 53. The counter-bored region of the protector is above the lock body, so long as the shackle remains unlocked. Then, the second part 41 of the shackle protector may be engaged

with the first part, by sliding the channel of the second part along the second leg 57 of the shackle and simultaneously interengaging the pins 48 of the first part with the bores 52 in the second part. The second part is slid fully to engage its rebates 51 with shoulders 47 of the first part, thus bringing the recesses 54 of the first and second parts into alignment with each other, the lugs 16 being located in those recesses.

Once the two parts have been interengaged as described above, the body 46 of the padlock may be swung about the one end 44 of the first leg 43 until the one end 58 of the second leg 57 overlies the opening 59 in the padlock body for that one end 58 of the second leg, whereafter the shackle may be returned to its locked position by applying an axial force to the padlock body.

This brings the counter-bore 55 over the upper part of the body and fully traps the protector in position on the shackle of the padlock. The protector cannot be removed from the shackle until the padlock is released once more and the shackle is swung away from the body 46.

The two parts 40 and 41 of the shackle protector may be made of relatively high strength material, such as a cast stainless steel. In this case, the pins 48 may be formed integrally with the first part 40, or they could be formed separately and let into the first part in an appropriate manner. Either way, the shackle protector is relatively cheap and simple to manufacture, and yet imparts to a relatively cheap padlock much greater strength and security than otherwise could be achieved with such a padlock.

Claims

CLAIMS 1. A security device for a connection having a pair of mating flanges bolted together, which device is in the form of a strap adapted to encircle the connection, said strap comprising a plurality of links pivoted together, each said link having a base section and a pair of side plates depending from opposed sides of the base section, and there being a security connector to secure together the two ends of the strap, whereby in use the strap is passed around the connection so that the base section of each link overlies the periphery of the flanges making up the connection and the side plates extend over the outwardly-directed faces of the flanges, the security connector being used to secure together the ends of the strap whereby the side plates resist removal of the strap from the connection and also restrict access to bolts making up the connection.
2. A security device as claimed in claim 1, wherein the strap comprises a plurality of similar main links pivoted together and a pair of end links disposed one each end of the strap and adapted to permit their connection together by means of the security connector.
3. A security device as claimed in claim 2, wherein between two adjacent main links there is one or more intermediate links pivoted to the main links to increase the separation therebetween.
4. A security device as claimed in claim 2 or claim 3, wherein the base section of each link is of generally rectangular shape, in plan.
5. A security device as claimed in claim 4, wherein each main link is provided along one edge with a pivot pin and along the opposed edge with a receptor for the pivot pin of an adjacent like link, whereby the interconnected

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links may pivot one with respect to its neighbouring links in the strap, about the axes of the pins.
6. A security device as claimed in claim 5, wherein each receptor is in the form of a channel defining a re-entrant slot.
7. A security device as claimed in claim 6, wherein each pin is of generally circular cross-sectional shape but having a flat formed therealong, the width of the entrance to the re-entrant slot being substantially equal to the crosssectional width of the pin across the flat whereby the pin of one link may be entered into the slot of another link by appropriate relative positioning of said one link with respect to the other link.
8. A security device as claimed in claim 7, wherein the flat on the pin of said one link is disposed relative to the plane of the base section of the link such that the pin may be entered into the channel of another link when there is an obtuse angle between the external surfaces of the base sections of the two links.
9. A security device as claimed in any of claims 6 to 8, wherein the crosssectional shape of the re-entrant slot is generally circular and of a diameter substantially equal to the diameter of the pivot pin.
10. A security device as claimed in any of claims 2 to 9, wherein each of the end links is provided with an outwardly-projecting lug having a hole formed therein, whereby the end links may be secured together by a lock mechanism having a locking member passing through the holes in the lugs.
11. A security device as claimed in any of the preceding claims, wherein each side plate has a generally triangular form, with the apex thereof directed internally of the encircling strap.

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12. A security device as claimed in any of the preceding claims, wherein the base section of each link is ventilated.
13. A security device as claimed in claim 10, in combination with a lock mechanism having a body and a shackle movable between locked and free positions with respect to the body, which shackle may be passed through the aligned holes of the lugs of the two end links.
14. A security device as claimed in claim 13, wherein the lock mechanism comprises one of a key-operated padlock and a combination lock.
15. A security device as claimed in any of the preceding claims, wherein each link is formed from a cast metal.
16. A security device as claimed in claim 1 and substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.
17. A protector for a lock mechanism having a lock body and aU-shaped shackle having first and second legs with one end of the first leg being mounted on the body for movement between a locked position where the corresponding end of the second leg of the shackle is received in the lock body and a free position where access may be had to said corresponding end, said protector comprising first and second parts defining respective channels for receiving the first and second legs of the shackle, the first and second parts being provided with interlocking means configured to permit the interconnection thereof by relative sliding movement along the length of the channels so that the channels mate to define a chamber for reception of the shackle, whereby the protector may be fitted to the shackle when in the free position but after the shackle has been passed through a component to be secured by the lock mechanism, and after the two parts have been interconnected by relative sliding movement

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thereof, the protector is secured against removal from the shackle by moving the shackle to its locked position.
18. A protector as claimed in claim 17, wherein the interlocking means comprises a pin projecting from a surface of the first part in a direction parallel to the length of the channel therein, and a bore provided in the second part in which bore said pin is received when the two parts are joined together.
19. A protector as claimed in claim 18, wherein the first part has a pair of similar pins disposed one to each side of the channel and extending in a direction parallel to the length of the channel therein, and a second part has a corresponding pair of bores in which the pins are received when the two parts are joined together.
20. A protector as claimed in any of claims 17 to 19, wherein the two parts, when fitted together, define a skirt of greater internal cross-sectional shape than the mating channels, whereby when the protector has been fitted on a shackle and the shackle is moved to its locked position, said skirt surrounds a portion of the lock body to which the shackle is mounted.
21. A protector as claimed in any of claims 17 to 20, wherein the channel in the second part is provided with an abutment which prevents the engagement of that part with a leg of the shackle other than by relative sliding movement along the length of the leg of the shackle.
22. A protector as claimed in claim 17 and substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.