The lockable tamper-evident device is suitable for securing a closure member in its closed position to an article. The device comprises a pair of arms (1,1') which are movable between an open position in which the arms (1,1') are engagable with an article and/or a closure member, and a locked-closed position in which disengagement of the arms from the article and/or the closure member is prevented by engagement of a cooperable locking means. Preferably, the arms (1,1') are engagable with a projection 7,7' extending either from the article and through an opening in the closure member or from the closure member and through an opening in the article. Preferably, the cooperable locking means (8,10,11,12) is carried by the arms (1,1'), activation of the locking means (8,10,11,12) being brought about by movement of the arms (1,1') to the locked-closed position. In the locked-closed position removal of the closure member is prevented by engagement of the arms (1,1') with the article and/or the closure member.

This invention relates to a locking device and in particular to a lockable, 
tamper-evident device for securing a closure member in its closed position 
to an article. 
Conventionally, locking devices necessitate the use of a tool, for example 
a key, for locking and/or unlocking purposes. With such locks unauthorised 
opening and subsequent locking is not always evident and potential 
duplication of the tool provides an additional security risk. Further 
problems associated with these locks would be apparent to the skilled 
person and include: accidental loss of the key necessitating breakage of 
the lock; the wear and tear of the engagable and movable parts of the lock 
and key; and the expense and maintenance of the lock. 
U.S. Pat. No. 5,522,627 discloses a reusable security seal. The seal 
comprises a pair of hingedly-mounted arms having co-operable locking means 
located at the free ends of the arms. Locking of the seal is effected by 
hinged movement of the arms towards each other and engagement of the 
co-operable locking means. 
DE-A-1761379 discloses a seal which is operable in a similar manner to the 
one disclosed in U.S. Pat. No. 5,522,627. However, in this case each of 
the hingedly-mounted arms has a recess which, when the device is in the 
locked-closed position, cooperate to trap and retain a cord or ribbon. 
The present invention overcomes the above problems by providing a cheap to 
produce and reliable, lockable device for which no separate tool is 
required for locking and/or unlocking purposes. The device provides a 
self-evident means for identifying when a closure member for an article 
has been tampered with in order to gain access to the article. Once the 
device is in a locked-closed position it is only removable by means which 
result in physical damage to the device which in turn provides evidence of 
tamper. Furthermore, once the device has assumed the locked-closed 
position it is not re-usable. Thus, it may be more appropriate to refer to 
the lockable device as a security seal. Each seal is uniquely 
identifiable, for example, by a bar code or serial number or by other 
means which would be apparent to the skilled person. Accordingly, any 
attempted replacement of a broken seal with a new seal would be evident by 
comparison of the respective device identification means. 
The present invention provides a lockable tamper-evident device for 
securing a closure member in its closed position to an article, comprising 
a pair of arms mounted by a hinge to each other which arms are movable 
along a defined radial path relative to the hinge between an open position 
wherein the free ends of the arms remote from the hinge are spaced apart 
from each other thereby permitting respective outwardly-facing portions of 
the arms to engage with the article and/or closure member, and a 
locked-closed position in which disengagement of the arms from the article 
and/or the closure member is prevented by engagement of a co-operable 
locking means carried by the arms, activation of the locking means being 
brought about by radial movement of the arms towards each other and into 
the locked-closed position, and when in the locked-closed position removal 
of the closure member being prevented by engagement of the arms with the 
article and/or the closure member. 
In one embodiment of the present invention, the arms are engagable with a 
projection extending either from the article and through an opening in the 
closure member or from the closure member and through an opening in the 
article. In the latter embodiment, the projection may extend through an 
opening provided in an outwardly facing part of the article. 
The projection and the arms are adapted to engage with each other. In a 
preferred embodiment, the arms form a socket in the locked-closed position 
which is engagable with a ball located at the free end of the projection. 
Alternatively, the arms may carry inwardly facing edges which, in the 
locked-closed position, grip corresponding grooves located on the 
projection. Preferably, the projection and the corresponding opening are 
of non-circular cross section to minimise potential rotation of the 
closure member about the projection. The present invention includes 
further means for engagement of the arms and the projection which would be 
apparent to the skilled person. 
Preferably the arms are simultaneously engagable, when in the open 
position, with two projections and when in the locked-closed position the 
cooperable locking means prevents disengagement of the arms from the two 
projections. 
In a preferred embodiment, each arm carries an outwardly extending portion, 
and when the arms are in the locked-closed position, the outwardly 
extending portions protrude in substantially opposite directions, and when 
the arms are in the open position, said portions are engagable with 
corresponding orifices located on facing surfaces of the two projections. 
In a more preferred embodiment, the two projections have a pair of holes 
located in facing surfaces for engagement with the outwardly extending 
portions of the arms. 
In one embodiment the arms are hingeable and the outwardly extending 
portions protrude from the outer surface of each arm which is remote from 
the hinge. In a more preferred embodiment, the arms are hingeable 
end-to-end and the outwardly extending portions are located in close 
proximity to the hingeable ends of the arms. In the latter embodiment, the 
distance between the respective free ends of the outwardly extending 
portions is greater in the locked-closed position than it is in the open 
position. This is achievable by way of the hingeable arrangement of the 
arms which is described below. In the locked-closed position, the arms are 
substantially parallel to each other and the internal angle formed by the 
arms and the hinge is substantially zero. As the internal angle is 
increased by hinged movement of the arms, the free ends of the outwardly 
extending portions follow a defined radial path relative to the hinge. At 
a given internal angle, the free ends of the outwardly extending portions 
will be diametrically opposite each other at which point the distance 
between the free ends is a maximum. Further hinged movement increases the 
internal angle and simultaneously reduces the distance between the 
respective free ends of the arms until the arms reach the open position in 
which they are engagable with the two projections. In principle, the 
maximum internal angle between the arms is limited by abutment of the 
hingeable ends of the arms with each other. However, the maximum internal 
angle is generally restricted to less than 180.degree. by cooperation of 
an abutment shoulder extending from the hingeable end of one arm with the 
hingeable end of the other arm. Restriction of the internal angle reduces 
undesirable stress on the hinge. 
One or both of the two projections may be slidably mountable to the article 
and/or the closure member. In this embodiment the outwardly extending 
portions are barbed so that, following engagement of the outwardly 
extending portions with the two projections, inadvertent disengagement of 
an outwardly extending portion from its projection does not occur as a 
result of slidable movement of the projection/s. An advantage of this 
embodiment is that the barbed portions automatically provide a tightening 
of the device and the article and/or the closure member during actuation 
of the arms from the open position to the locked-closed position by a 
relative drawing together of the two projections. 
According to a preferred embodiment of the present invention, one of the 
arms of the device has a line of weakness located between the locking 
means and the point of engagement of the arm with the projection, said 
line of weakness providing convenient means for removal of the device. 
Simple manual force, for example fingers acting directly on the arm, is 
sufficient to break the arm and release the seal. 
In one embodiment, the device is simultaneously engagable with a projection 
extending from the closure member and with a projection extending from the 
article. In this embodiment, the closure member is preferably mountable to 
the article at a position away from the point of engagement of the device 
and the two projections.

Referring to FIG. 1, a pair of arms 1,1' are mounted end-to-end by a hinge 
2. The arms and hinge are formed as an integral plastics mounding. Each 
arm 1,1' carries a curved outwardly extending portion 3,3' located on the 
outer surface 4,4' of each arm 1,1' which is remote from the hinge 2. The 
arms 1,1' are movable along a defined radial path relative to the hinge 2. 
At a given position, identified by the line A, the free ends 5,5' of the 
curved portions 3,3' are diametrically opposite each other. In this 
position, the distance between the respective free ends 5,5' is a maximum. 
Any further increase of the internal angle, .phi., formed by the arms 1,1' 
and the hinge 2, reduces the distance between the respective free ends 
5,5' of the curved portions 3,3' until an open position is achieved in 
which the curved portions 3,3' are engagable with a pair of openings 6,6' 
located in facing surfaces of a pair of corresponding projections 7,7' 
forming part of the article (not shown) to be secured. The projections 
7,7' are of rectangular cross-section and extend through corresponding 
rectangular slots provided in the closure member (not shown). Only the 
free ends of the projections 7,7' are illustrated. 
A resiliently yieldable arrow-head formation 8 is located on the inside 
surface 9 of the arm 1. Hinged actuation of the arms 1,1' (in the 
direction of the arrows) towards each other permits sliding insertion of 
the arrow-head formation 8 through a reduced diameter mouth 10 located on 
the facing inside surface 9' of the arm 1' and into a corresponding socket 
11 located within the arm 1'. The reduced diameter mouth 10 defines an 
inwardly facing abutment shoulder 12. Following insertion of the 
arrow-head formation 8 into the socket 11, retraction of the arrow-head 
formation 8 is prevented by abutment of the arrow-head formation 8 with 
the shoulder 12 of the reduced diameter mouth 10. This represents the 
closed-locked position of the arms 1,1'. 
During actuation of the arms 1,1' from the open position to the 
closed-locked position, the curved portions 3,3' tend to pull the 
projections 7,7' together thereby tightening the lockable assembly. 
The arm 1' carries a protective flange 13 along both opposite side surfaces 
(not shown) of the arm 1' (only one is shown). During actuation of the 
arms 1,1' to the locked-closed position, the flanges 13 slide over the 
corresponding opposite side surfaces (not shown) of the arm 1 and protect 
the arrow-head formation 8, the reduced diameter mouth 10, the abutment 
shoulder 12 and the socket 11 from tamper. 
FIG. 1 also illustrates a single barb variant 14 which is inter-changeable 
with the arrow-head formation 8 on arm 1. Following actuation of the arms 
1,1' from the open position to the locked-closed position the single barb 
14 is slidingly inserted into, though not retractable from the 
corresponding reduced diameter mouth 15 located on the inside surface 9' 
of the arm 1'. The abutment shoulder 16 and the socket 17 function as 
described above for the shoulder 12 and the socket 11 respectively. 
An extension 18 of the hinged end 19' of the arm 1' provides an abutment 
surface 20. The surface 20 prevents excess hinged movement of the arms 
1,1' by abutment of the hinged end 19 of the arm 1 with the surface 20. 
Referring to FIG. 2, the arms 1,1' are in the locked-closed position. The 
barbed portions 3,3' are engaged with the projections 7,7' and the 
arrow-head formation 8 is non-retractably inserted into the socket 11 
located in the arm 1'. A line of weakness 21 is located across the arm 1' 
between the barbed portion 3' and the socket 12. 
Referring to FIG. 3, the arm 1' has been broken along the line of weakness 
21, thereby allowing the barbed portions 3,3' to hinge towards each other 
to an open position in which they are releasable from the openings 6,6' of 
the projections 7,7'. The illustrated device is now broken, unusable and 
provides evidence of tamper. In practice, the device is only intended to 
be broken by authorised personnel.