WO2014037051A1

WO2014037051A1 - Tamper-evident security seal

Info

Publication number: WO2014037051A1
Application number: PCT/EP2012/067546
Authority: WO
Inventors: André Goby
Original assignee: Stoba Ag
Priority date: 2012-09-07
Filing date: 2012-09-07
Publication date: 2014-03-13

Abstract

The tamper-evident seal (100) according to the invention comprises a rotor (2) having a stem (12) around which a filament can be wound, disposed in a housing (1). A manipulation element (3) is disposed at one extremity of the stem (12) of rotor (2), and is joined to the rest of the stem (12) by a torsional break-off portion arranged to fail once a predetermined torque value is exceeded, thereby causing the manipulation element (3) to separate from the rotor (2). The manipulation element (3) remains in place during normal operation of the seal (100), and separation of the manipulation element (3) from the rotor (2) evidences tampering of the seal (100) and/or fraud.

Description

TAMPER-EVIDENT SECURITY SEAL

The present invention relates to a tamper-evident security seal for attaching a sealing filament to a hasp, staple, lock parts, or similar mechanisms holding two parts

together. Such seals are commonly used for sealing shipping containers, safety pins of fire extinguishers, and so on. A break in the sealing filament or in the seal indicates tampering such as access of a container or use of the sealed object by unauthorised persons.

Traditionally, such seals comprise a loop of a filament such as a metallic wire, the seal body comprising a piece of malleable metal such as lead crimped onto the wires so as to hold them together. This requires a special crimping tool for crimping the lead seal, and by heating the lead it can be possible to remove one of the ends of the filament from the seal and later to reinsert it without the lead seal being visibly altered.

US 5,402,958 describes a two-piece plastic seal exhibiting several improvements over traditional lead seals. The seal comprises a closed-ended hollow housing with a rotor click- fitted into the open end of the housing. The rotor

comprises a stem with two parallel through holes for permitting the passage of a filament, and the housing comprises a pair of corresponding openings alignable with one of the through holes, and a single opening alignable with the other of the through holes. A ratchet mechanism between the rotor and the housing permits rotation in one direction only. The seal is operated by first inserting a filament into the single opening sufficient for it to pass fully through the corresponding hole in the rotor stem, and rotating the rotor so as to wind the filament around the stem of the rotor. This rotation is carried out in one embodiment by means of a tool such as a flathead

screwdriver, or in another embodiment by turning a break- off tab integral with the rotor. The free end of the filament is then passed through the object to be sealed, and is then passed through the pair of openings and the corresponding hole in the rotor stem. The rotor is then again rotated to wind the filament around the stem of the rotor.

Any attempt to tamper with the seal will leave visual evidence on the seal, such as scratching, marring,

indentations, and so on

This arrangement however presents several disadvantages: the seal is relatively bulky, resulting in a relatively low packing density when bulk-packed. Furthermore, rotation of the rotor either requires a separate tool, use of which may itself mar the surface of the seal, or a break-off tab, which the technician is required to break off after installing the seal. This generates waste, and the risk of broken-off tabs being left on the ground, creating a littering problem. Furthermore, the broken-off tab does not assist in providing evidence of tampering or fraud.

An object of the present invention is thus to overcome at least some of the above-mentioned disadvantages of prior art seals. This object is attained by a seal suitable for use with a flexible filament according to the invention. The seal comprises a housing with a cavity and at least one pair of openings formed in the sidewalls of the housing, and opening into the cavity. Disposed in this cavity is a rotor which has a longitudinal axis, the rotor comprising a stem provided with at least one hole alignable with the at least one pair of openings in the housing. The at least one pair of openings in the side wall of the housing and the at least one hole are arranged to permit the insertion of a flexible filament through the housing and the rotor. A oneway mechanism, e.g. a ratchet mechanism, is provided for permitting relative rotational motion between the rotor and the housing in a first direction of rotation around the longitudinal axis of the rotor, and to prevent relative rotational motion between the rotor and the housing in a second direction of rotation around the longitudinal axis of the rotor, this second direction being opposite to the first direction. A manipulation element such as a knob is situated at an extremity of the stem, and permits manual rotation of the rotor, e.g. between finger and thumb. The rotor further comprises a torsional break off portion, i.e. a portion that will fail and break when subjected to a torque which exceeds a predetermined torque value, thus separating the manipulation element from the rest of the rotor. This torsional break off portion is situated in the interior of the seal, i.e. within the interior of the envelope of the entire seal including the housing, rotor, and the manipulation element, and thus inaccessible from the exterior of the seal.

In consequence, the manipulation element can remain

attached to the rest of the seal during normal operation of the seal. Any attempt at tampering with the seal by back- winding the manipulation element will result in the

manipulation element breaking off, providing evidence of such tampering. Furthermore, since the manipulation element remains attached to the seal in normal operation thereof, no parts are broken off in normal use of the seal which may be left on the ground contributing to littering, nor are such parts wasted, saving plastic and keeping manufacturing costs down. In addition, no tools are required to operate the seal, thus there is no risk of marring the seal during normal installation thereof. Any attempt at tampering is thus rendered evident by any damage to the seal.

In an embodiment, the stem, the one-way mechanism, the manipulation element and the torsional break off portion are arranged such that on application of a torque in the above-mentioned second direction, the torsional break off portion is arranged to fail at a predetermined torque val lower than that required to cause failure of the one-way mechanism. Such failure typically occurs in the case of a ratchet one-way mechanism by the pawls of the ratchet mechanism jumping the teeth of the ratchet gear, or by the pawls breaking off of the stem. By ensuring that the torsional break off portion fails and causes the

manipulation element to break off of the stem before such failure, tampering by attempting to back-wind the stem is prevented.

In an embodiment, non-dismountable fixing means are

provided for preventing removal of the rotor from the housing, preventing tampering by removing the rotor.

In an embodiment, the seal comprises alignment means arranged such that on assembling the rotor into the

housing, the at least one hole is aligned with the at least one pair of openings, ensuring that the technician

installing the seal can insert the filament into the seal directly with the seal in the state in which it is

delivered, without having to manually and visually align the at least one hole with the at least one pair of openings, saving installation time and making installation of the seal easier.

In an embodiment, the alignment means comprise at least one abutment for preventing assembly of the rotor into the housing in a relative angular orientation between the rotor and the housing in which the at least one hole is not aligned with the at least one pair of openings. This provides a simple way of ensuring alignment between the rotor and the housing on assembly.

In an embodiment, either the rotor or the housing comprises a groove and at least one lug, and the other of the rotor or the housing comprises at least one ridge arranged to interact with the groove so as to constitute the above- mentioned non-dismountable fixing means. The at least one ridge comprises at least one gap for permitting the passage of the least one lug on assembly of the seal. When the at least one gap is rotationally-aligned with the least one lug, the at least one hole in the stem of the rotor is rotationally aligned with the at least one pair of openings in the housing. This provides strong non-dismountable fixing means and reliable alignment of the rotor in the housing on assembly. Furthermore, when the at least one hole and the at least one pair of openings are not aligned, e.g. when the seal is in use, the at least one lug can abut on the ridge and thereby provide extra resistance to attempts to force the rotor from the housing, increasing the strength and resistance to tampering of the seal.

In an embodiment, the least one ridge is situated on the housing, for instance on the side wall of the cavity in the housing, and the groove and the at least one lug are situated on the rotor with the at least one groove situated between the at least one lug and the manipulation element. This provides particularly simple construction, resulting in a relatively simple moulding dies, keeping manufacturing costs low.

In an embodiment, at least one of the rotor and the housing is/are transparent or translucent, rendering tampering more visible and evident.

In an embodiment, the housing comprises an identification code on and outer surface thereof, and the manipulation element comprises at least part of said identification code repeated on and outer surface thereof. If these codes match, the seal is likely untampered, however if these codes do not match, tampering and fraud is immediately evident .

In an embodiment, the identification code on the housing and the at least part of the identification code on the manipulation element align when the hole and the at least one pair of openings align, providing simple visual

indication of the alignment of the hole in the stem of the rotor and the at least one pair of openings in the housing.

In an embodiment, the one-way mechanism comprises a ratchet formed by at least one ratchet pawl provided on the rotor and a ratchet gear provided in the interior wall of the opening of the housing. Typically, the number of ratchet pawls would be two, three, or four. This presents a simple, easy to manufacture construction of the one-way mechanism, and ensures that the seal can be made from only two

separate components.

In an embodiment, the seal comprises a tab extending from an outer surface of the housing, which in further

embodiments either forms an extension of this outer

surface, or extends substantially perpendicular thereto. This presents an enlarged area for applying a logo, serial number, or other information.

In an embodiment, the housing has a polygonal cross- section, providing easy gripping by the installing

technician, the corners of the housing at the end of the housing proximate to the manipulation element being

radiused or chamfered, preventing the corners from being easily placed against a hard object for the purposes of attempting to drive the rotor out of the housing.

In an embodiment, the end face of the housing proximate the manipulation element does not present any exposed surface perpendicular to the longitudinal axis of the rotor. Thus, with the manipulation element in place, there are no surfaces which can be easily placed against a hard object for the purpose of attempting to drive the rotor out of the housing. The invention will now be elaborated upon by means of non- limiting embodiments illustrated in the figures, which show:

Fig. 1: a perspective view of the exterior of a seal according to a first embodiment of the invention;

Fig. 2: a perspective view of the exterior of the sea according to a second embodiment of the invention;

Fig. 3: a perspective exploded view of the seal of figure 1;

Fig. 4: a perspective view of an assembled seal;

Fig. 5: a cross-section through an assembled seal;

Fig. 6: two perspective views of installed, tampered seals ;

Fig. 7: a perspective view of the exterior of a further embodiment of a seal according to the

invention; and

Fig. 8: a perspective view, a side elevation and a front elevation of a yet further embodiment of a seal according to the invention.

In the figures, like parts are designated with like reference signs.

Figure 1 shows a seal 100 according to a first embodiment of the invention. The seal 100 comprises a housing 1 comprising a cavity in which is disposed a rotor 2. As illustrated (more clearly visible on figure 3) , the cavity- is constituted as a through-bore, which permits an

extremely simple configuration of the moulding dies to produce it in comparison to those required for a closed- ended cavity. Rotor 2 is irremovably fitted into the cavity in housing 1, and at one end of the rotor 2 a manipulation element 3 is provided, and is arranged to be rotated between finger and thumb by a technician. Manipulation element 3 is provided with a convenient gripping surface such as grooves, ridges, knurling or similar, and is arranged flush with an end face of housing 1 so as to prevent insertion of tools between housing 1 and

manipulation element 3, and also to prevent ingress of debris therein. Housing 1 further comprises openings 4a, 4b, which align with corresponding holes in rotor 2 (not visible on figure 1) , sized so as to permit the passage of a filament 5, which may be steel (coated or not coated) , nylon, or of any other commonly-used type, and would typically have a diameter of 1.4 mm or less, however greater diameters are conceivable. Corresponding openings are present on the opposite faces of housing 1 (not visible in figure 1), each corresponding opening being paired with opening 4a or 4b. As illustrated in figure 1, the free ends of filament 5 have been wound inside the seal 100 such that they no longer protrude. This further assists in preventing tampering, since the free ends of filament 5 cannot be gripped by fingers or tools. Alternatively, the free ends of filament 5 may be cut flush with the surface of the housing 1 after the seal is installed. At the end of the housing 1 proximate to the manipulation element 3, the corners 6 of the housing 1 are bevelled or chamfered, which prevents this end of the housing 1 from being placed against a hard object and the rotor 2 being driven from the housing 1 by force. These bevelled or chamfered corners 6 ensure that the seal 100 will slip from the hard object on the application of this force. Additionally, in the case in which the largest diameter of the manipulation element 3 is substantially equal to the diameter of the housing 1, such tampering is rendered even more difficult since there are no surfaces on the housing 1 that can be easily placed against a hard object as above.

It should be noted that, although the housing 1 has been illustrated as being of square cross-section, it can be any convenient shape, e.g. of triangular, rectangular,

pentagonal, hexagonal, circular, oval, or any other cross- section. However a square cross-section presents the advantages of being easy for the user to grip, and

permitting packing in bulk with minimal loss of space.

Figure 2 shows a seal 101 which differs from seal 100 of figure 1 in that only a single opening 4e is provided, and is sized so as to permit the passage of both free ends of filament 5 through the single opening 4e, and a

corresponding opening on the opposite side of housing 1

(not visible) . Correspondingly, rotor 2 is provided with a single, similarly-configured hole (not visible on figure 2) . In the foregoing, the details of the seals will be

described solely with reference to the embodiment of figure 1, however the modifications necessary to achieve the embodiment of figure 2 are self-evident for the skilled person.

Figure 3 shows an exploded perspective view of the seal of figure 1, with housing 1 and rotor 2 separated, in the state in which they would be immediately prior to assembly. In this figure it can be seen that housing 1 comprises a through-bore 7 of circular cross-section for receiving rotor 2. In the illustrated embodiment, the interior walls of this through-bore 7 are provided with a ridge 8 which interacts with a groove 9 situated at one end of the stem 12 of rotor 2, which together form a non-dismountable click-fit attachment means. As previously discussed, lateral openings 4a, 4b for the passage of a filament are provided in one face of housing 1, and corresponding openings 4c, 4d respectively are provided in the opposite face. Each of these pairs of openings 4a, 4c; 4b, 4d cooperate with corresponding lateral holes 9a, 9b

respectively in rotor 3, here illustrated as having

mutually-parallel central axes. The rotor 2 and the housing 1 are thus arranged such that a filament can be inserted through opening 4a, hole 9a, and opening 4c, and likewise through opening 4b, hole 9b, and opening 4d. Although openings 4a-d and holes 9a, b are illustrated as having central axes disposed diametrically to the housing 1 and rotor 2 and intersecting the longitudinal axis of rotor 2 and through-bore 7, this does not necessarily have to be the case: the openings and holes may be offset, provided that a filament may still be inserted through the housing 1 and rotor 2.

Filament separators 14a, 14b, 14c are provided to ensure that each section of filament 5 is isolated from its neighbouring section of filament 5, so as to prevent excessive friction and tangling of the filament 5 during installation of the seal 100. The space provided between the stem 12 of rotor 2 and the walls of the through-bore 7 provide a large capacity for winding filaments 5

therearound .

Ridge 8 is provided with two gaps 8a, 8b, for the passage of two lugs 10a, 10b provided on the rotor 2, on assembling the seal 100. The gaps 8a, 8b and the lugs 10a, 10b are positioned so as to prevent assembly unless holes 9a, 9b will automatically be in alignment with the corresponding pairs of openings 8a, 8c and 8b, 8d respectively once the seal 100 is assembled. In case of misalignment, the lugs 10a, 10b will abut against ridge 8, which forms an abutment to lugs 10a, 10b in this case, and thereby prevent

assembly. When the lugs 10a, 10b are aligned with gaps 8a, 8b, the rotor 2 can be fully inserted into housing 20, and the ridge 8 clips into groove 16 in the conventional manner (more clearly visible in the lower portion of figure 5) . A further advantage of lugs 10a, 10b is that, when the seal 100 is assembled, if the lugs 10a, 10b are not aligned with gaps 8a, 8b, the lugs will abut against groove 8 and thus present increased resistance to attempted tampering by attempting to force the rotor 2 back out of the housing 1. Although as illustrated two lugs 10a, 10b and two gaps 8a, 8b are provided, any convenient number of lugs and gaps may be provided. These features are likewise clearly visible in Fig. 5, which illustrates the seal in assembled state.

Furthermore, housing 1 is further provided with an

interior-toothed ratchet gear 11a which cooperates with flexible ratchet pawls lib provided on stem 12 of rotor 2. Together, ratchet gear 11a and ratchet pawls lib (here illustrated as three ratchet pawls lib, however any

convenient number is conceivable) form a ratchet mechanism, so as to permit rotation of the rotor 2 with respect to housing 1 only in a first direction of rotation (which would normally be clockwise) , and to prevent rotation of the rotor 2 with respect to housing 1 in a second direction of rotation opposite to the first direction of rotation (which would likewise normally be anticlockwise) . Interior- toothed ratchet gear 11a and ratchet pawls lib are formed integral with the housing 1 and the rotor 2 respectively.

Manipulation element 3 is connected to the stem 12 of the rotor 2 by a torsional break-off portion 15. This is a portion which is weaker than would be the case in which the stem 2 and the manipulation element 3 would be integrally formed and connected to each other over the whole of the cross-sectional area of the stem 12 where it meets the manipulation element 3. In the illustrations of figures 4 and 5, a triangular-shaped indent 13 of smaller area than the immediately-underlying stem 12 is formed which

penetrates through the base 13b of the manipulation element 3 such that the stem 12 joins the manipulation element 3 in the plane of its interior face 13a over a reduced area to that which would be the case if this indent 13 were not present. Where the stem 12 joins the manipulation element 3 thus defines a torsional break-off portion 15, which is adapted to break and cause the manipulation element 3 to separate from the stem 12 of the rotor 2 in case of an excess of torque being applied to the manipulation element 3. This torsional break-off portion must be strong enough to resist the torque applied during normal installation of the seal 100, during which the manipulation element 3 is rotated so as to wind filament 5 around the stem 12 of the rotor 2. However, attempts to tamper with the seal e.g. by attempting to rotate the manipulation element 3 in the above-mentioned second direction (which would usually be anticlockwise) so as to attempt to unwind the filament 5 will cause the torsional break-off portion to fail in torsion and twist off, separating the manipulation element 3 from the stem 12 of the rotor 2, thereby rendering such attempted tampering evident. The torsional break-off portion must therefore be weaker in torsion than the ratchet mechanism 11a, lib, such that the torsional break- off portion 15 fails at a lower applied torque than the ratchet mechanism 11a, lib. Although the illustrated shape of the indent 13 is triangular, other shapes are

conceivable such as circular, square etc. However, a triangular indent and thus a triangular-shaped torsional break-off portion presents the advantages of maximising the torsional shear of the material at the vertices of the triangle, and provides a series of sharp corners generating high stress concentrations from which torsional failure can propagate .

Alternatively, the torsional break-off portion 15 may be constituted by a weld, such as an ultrasonic weld or a laser weld, between the manipulation element 3 and the stem 12 of the rotor 2, in the case in which the manipulation element 3 and the remainder of the rotor 2 are formed as separate elements and then joined.

As is clearly visible on the figures, the torsional break- off portion 15 is situated in the interior of the seal 100, the volume of the seal being defined by the extremities of its outermost surfaces. In other words, the torsional break-off portion 15 is not located on an outer surface or face of the seal 100. In practical terms, in the case in which both the housing 1 and the rotor 2 are formed of non- translucent, non-transparent materials, the break-off portion 15 is not visible to a user on the assembled seal 100.

To use the seal 100, the user takes a filament 5, passes it through openings of an object to be sealed 17, such as the hasps of a lock, and then passes each free end through the housing 1 and rotor 2 by means of the openings 4a-d in the housing 1 and holes 9a, 9b in the rotor 2 such that the free ends of the filament 5 protrude from the seal 100. The manipulation element 3 is then rotated in the first

direction, e.g. clockwise, so as to wind the filament 5 around the stem 12 of the rotor 2. Subsequently, the free ends of the filament 5 which protrude from the seal 100 may be trimmed if necessary, and the filament 5 further wound up if necessary and/or desired. Contrary to the prior art seal described above, the manipulation element 3 remains attached to the rotor 2 when the seal 100 is operational, and separation of the manipulation element 3 from the seal 100 indicates attempted tampering and/or fraud. To remove the seal, it is necessary to cut the filament.

Figure 6 shows two views of an installed seal which has been tampered with by attempting to rotate the manipulation element 3 in a second direction, which would usually be anticlockwise. Torsional break-off portion 15 has failed, and shows clear evidence of torsional failure on both the end of the stem 12 and on the interior face 13b of the manipulation element 3. As a result, manipulation element 3 has separated from the remainder of the rotor 2, providing evidence of tampering.

Figure 6 also illustrates a particular adaptation of the seal 100 of the invention to further prevent tampering and fraud. The outer surface of the housing 1 is provided with a serial number 18 etched (e.g. by laser), stamped, or printed thereupon. Manipulation element 3 likewise

comprises the last several digits of serial number 18, in the present example the last six digits, although any other convenient number is possible. Thus, in case of fraud, if the rotor 2 is replaced with a replacement rotor, the serial number will not match with that of the original seal housing 1, evidencing the fraud and tampering, and

rendering undetectable fraud more difficult.

Figure 7 shows a further variation of a seal 102 according to the invention, which differs from the foregoing

embodiments in that housing 1 comprises a tab la extending from the main body of the housing 1 and forming an

extension of one face lb of housing 1. This provides a greater surface area upon which a longer serial number and/or a logo can be provided. As in figure 6, manipulation element 3 may likewise comprise the last several digits of a serial number provided on the housing 1.

Figure 8 shows a perspective view, a side view and a front view of a yet further variation of a seal 103 according to the invention, which differs from that of figure 7 in that the tab lc extends substantially perpendicular to an outer face lb of the housing 1, this likewise provides a greater surface area upon which a longer serial number and/or a logo can be provided, and manipulation element 3 may again likewise comprise the last several digits of a serial number provided on the housing 1. Naturally, other angles of the tabs la, lc with respect to the housing 1 are possible .

In all of the foregoing embodiments, both the rotor 2 and the housing 1 may be constructed of the same or different coloured materials, which may be transparent, translucent, or non-transparent. In the case of different-coloured rotors 2 and housings 1, fraud is made more difficult since the colours of the parts must be made to match those of the original seal. In the case in which the housing 1 and optionally also the rotor 2 are made of transparent

plastic, the winding of the filament around the rotor is visible, and fraud or tampering is more easily visible.

Suitable materials for the seal include but are not limited to SMMA (Styrene Methyl Methacrylate) , a thermoplastic acrylic copolymer.

Thus, the seals as described above present at least the following characteristics:

- during normal operation, no parts are detachable, and no tools are required for operation;

- only two separate parts are required to construct the seals, namely the rotor 2 and the housing 1, each being intimately moulded; - each of the two separate parts may be coloured differently, or made transparent, rendering

undetectable tampering and fraud more difficult;

- the separation of the manipulation element from the rest of the seal signifies tampering;

- the seal is very compact and aesthetically shaped;

- the illustrated square cross-section of the housing facilitates manipulation of the seal during

installation;

- the seal has a large filament winding capacity,

rendering trimming of the filament unnecessary if the filaments are supplied at an appropriate length;

- when the seal is provided with serial numbering,

matching serial numbers on the housing and the manipulation element indicates that the seal is intact .

Although the invention has been described with reference t specific embodiments, it is evident to the skilled person that variations thereof are possible without departing fro the invention as defined by the scope of the claims.

Claims

1. Seal (100; 101; 102; 103) for use with a flexible filament (5) comprising:

- a housing (1) comprising a cavity (7) and at least one pair of openings (4a, 4c; 4b, 4d) formed through the housing (1) and opening into the cavity (7);

- a rotor (2) disposed in the cavity (7) and having a longitudinal axis, said rotor (2) having a stem (12) provided with at least one hole (9a; 9b) alignable with the at least one pair of openings (4a, 4c; 4b, 4d) in the housing (1), the at least one pair of openings (4a, 4c; 4b, 4d) and the at least one hole (9a; 9b) being arranged for the insertion of a flexible filament (5) through the housing (1) and the rotor (2);

- a one-way mechanism (11a, lib) arranged to permit

relative rotational motion between the rotor (2) and the housing (1) in a first direction of rotation about said longitudinal axis and to prevent relative rotational motion between the rotor (2) and the housing (1) in a second direction of rotation, opposite to said first direction of rotation, around said longitudinal axis;

- a manipulation element (3) situated at an extremity of the stem (12) for permitting manual rotation of the rotor (2);

characterised in that the rotor (2) further comprises:

- a torsional break-off portion (15) arranged between the stem (12) and the manipulation element (3), the torsional break off portion (15) being situated in the interior of the seal (100; 101; 102; 103).

2. Seal (100; 101; 102; 103) according to claim 1, wherein the stem (12), the one-way mechanism (11a, lib), the manipulation element (3) and the torsional break-off portion (15) are arranged such that on application of a torque in the second direction, the torsional break-off portion (15) is arranged to fail at a predetermined torque value lower than a torque value required to cause failure of the one-way mechanism (11a, lib) .

3. Seal (100; 101; 102; 103) according to claim 1 or 2, further comprising fixing means (8, 16) for preventing removal of the rotor (2) from the housing (1) .

4. Seal (100; 101; 102; 103) according to one of claims 1-3, further comprising alignment means (8a, 8b, 10a, 10b) arranged such that on assembling the rotor (2) into the housing (1), the at least one hole (9a; 9b) is aligned with the at least one pair of openings (4a, 4c; 4b, 4d) .

5. Seal (100; 101; 102; 103) according to claim 4, wherein the alignment means (8a, 8b, 10a, 10b) comprise at least one abutment (8) arranged to prevent assembly of the rotor (2) into the housing (1) in a relative angular orientation between the rotor (2) and the housing (1) in which the at least one hole (9a; 9b) is not aligned with the at least one pair of openings (4a, 4c; 4b, 4d) .

6. Seal (100; 101; 102; 103) according to claims 3 and 5, wherein one of the rotor (2) and the housing (1) comprises a groove (16) and at least one lug, and the other of the rotor (2) and the housing (1) comprises at least one ridge (8) arranged to interact with the groove (16), the at least one ridge (8) comprising at least one gap (8a; 8b) for permitting the passage of the at least one lug (10a; 10b) on assembly of the seal (100; 101; 102; 103), and wherein the at least one hole (9a; 9b) is aligned with the at least one pair of openings (4a, 4c; 4b, 4d) when the at least one gap (8a; 8b) is aligned with the at least one lug (10a;

10b) .

7. Seal (100; 101; 102; 103) according to claim 6 wherein the at least one ridge (8) is situated on the housing (1) , • and the groove (16) and the at least one lug (10a; 10b) is situated on the rotor (2), the at least one groove (16) being situated between the at least one lug (10a; 10b) and the manipulation element (3).

8. Seal (100; 101; 102; 103) according to any preceding claim, wherein at least one of the rotor (2) and the housing (1) is transparent or translucent.

9. Seal (100; 101; 102; 103) according to any preceding claim, wherein the housing (1) comprises an identification code (18) on an outer surface thereof, and the manipulation element (3) comprises at least part (19) of said

identification code (18) on an outer surface thereof.

10. Seal (100; 101; 102; 103) according to claim 9, wherein the identification code (18) on the housing and the at least part (19) of the identification code (18) on the manipulation element (3) are arranged to align when the hole (9a; 9b) and the at least one pair of openings (4a, 4c; 4b, 4d) align.

11. Seal (100; 101; 102; 103) according to any preceding claim, wherein said one-way mechanism (11a, lib) comprises a ratchet (11a, lib) .

12. Seal (100; 101; 102; 103) according to any preceding claim, wherein said housing (1) further comprises a tab

(la, lc) extending from one exterior surface (lb) thereof.

13. Seal (102; 103) according to claim 12, wherein said tab (la, lc) forms an extension of one exterior surface (lb) of the seal (1), or extends substantially

perpendicular to one exterior surface (lb) of the housing (1) -

14. Seal (100; 101; 102; 103) according to any preceding claim, wherein the housing (1) is of polygonal cross- section, the corners (6) of the housing (1) at the end of the housing (1) proximate to the manipulation element (3) being radiused or chamfered.

15. Seal (100; 101; 102; 103) according to any preceding claim, wherein the end face of the housing (1) proximate to the manipulation element (3) does not present any surface perpendicular to the longitudinal axis of the rotor (2).