BACKGROUND OF THE INVENTION

[0001] Security seals are widely used to demonstrate the integrity of a closed container, truck, roll pallet, cage or box to demonstrate, for example, that they have not been opened during transit. Typically such security seals are made from plastics material and comprise a strap with a plug at one end and a socket at the other end. The socket includes a one-way lock. In this way, the security seal is threaded through a locking point and the plug inserted into the socket. The plug is then locked irremovably into the socket so that the only way in which the security seal can subsequently be removed is by destroying it. Typically the security seal includes a unique serial number so that it can be confirmed that the same seal is still present after transport as was applied before transport, and the security seal may include a flag portion to carry this serial number.

SUMMARY OF THE INVENTION

[0002] Attempts are made to breach the security of such seals by, for example, cutting the strap portion of the seal to enable it to be removed and the container, or whatever, opened. Then, after replacing the security seal the cut ends of the security seal are adhered or welded together. Such tampering, particularly when heat welding is used, can be difficult to spot when the security seal is checked for integrity.

[0003] According to this invention such a security seal includes a recognisable sequence of indicia extending along substantially the whole length of the strap portion. The presence of the recognisable sequence of indicia along the length of the strap make it almost impossible to cut such a strap and reconnect the cut ends without disrupting the sequence of indicia so that it is immediately evident that the security seal has been tampered with.

[0004] Preferably the seal carries a recognisable sequence o individual indicia on opposite sides of the strap. In this case the indicia on opposite sides of the strap are preferably of different form thus, they may be of different typestyle and/or indicia on one side of the strap may be recessed whilst, on the other side they are raised, for example. The indicia may be “joined up” in the manner o handwriting or, alternatively, have the form of normal: printing. It is also preferred that any space between adjacent indicia on one side of the strap is locate directly opposite indicia on the opposite side of the stray so that, at no point, can a cut be made through the stray without cutting through indicia on one or other side of the strap. To further assist this it is convenient if the indicia on one side of the strap are in an “italic” font and so are sloping in one direction, whereas the indicia on the other side of the strap are either in a normal font o: are arranged to be inclined in the opposite direction. In this way the indicia on opposite sides of the stray certainly overlap one another and any spaces in between.

[0005] The recognisable sequence of indicia may be, for example, the letters of the alphabet arranged in alphabetical order along the length of the strap or may be formed by a continuous number sequence. The alphabet may be English or that of another language such as Greek or Russian. Where the indicia are formed by letters they mad even form a recongnisable long word such a: “supercalifragalisticexpealedotious” or even be arranged to form a well known phrase such as an advertising slogan. In one particular example the recognisable sequence of individual indicia are provided by intercalated upper and lower case indicia arranged in alphabetical order extending from one end of the strap to the other.