TECHNICAL FIELD
[0001] The present invention concerns tags, in particular RFID tags, for gas bottles and
cylinders and a method for fixing RFID tags on such bottles and cylinders.
BACKGROUND ART
[0002] The principle of tagging objects, for example gas bottles and cylinder, with RFID
tags is known in the art.
[0003] RFID tags (or transponders) are devices that allow an electronic, machine readable
identification of the object carrying said tag. A tag usually includes an RFID chip
and an antenna in order to be able to transmit information (for example an identity
code) to an RFID reader.
[0004] Usually, to allow the reading of a tag, the reader respectively antenna must be placed
close to the tag (respectively with fixed readers the tag be placed within the magnetic
field of the RFID reader antenna).
[0006] In
WO 2007/057874, the invention relates to an assembly comprising a bottle of gas and a rod shaped
transponder (metal rod RFID tag), wherein the bottle has a convex upper face and a
metal valve. The transponder is located above and close to the upper surface and is
oriented in an essentially radial direction this increasing the reading distance of
such tags.
[0007] In
WO 2007/141733, the idea is to use the presence of a metal pull-ring fixed to the bottle by metal
plates to attach the tag to one of said metal plates such that the tag is in a protected
position. However, in this example, the pull-ring must be present on the bottle otherwise
the tag cannot be mounted in a protected position.
[0008] A further example is given in
GB 2 288 103. In this publication, a magnetic transponder is mounted around the valve fitting
on the ferrous body of a compressed gas bottle to enable remote identification of
the bottle. A metal valve guard encircles the valve filling, for the protection of
the filling during transportation, which shields the bottle transponder from an external
reader/exciter. In order to couple RF signals between the reader/exciter, which is
outside of the valve guard and the transponder, which is inside of the valve guard,
a coupler is provided having a first receive and transmit antenna outside of the valve
guard and a second transmit receive and transmit antenna inside of a valve guard adjacent
the transponder antenna. Electrical current carrying wires interconnect the two coupler
antennae and extend through a wire receiving aperture formed in the valve guard.
[0009] In this example, the transponder has to be attached by some means to the valve fitting
and it has the further disadvantage that it needs a coupler to transmit signals through
the valve guard.
[0010] Another example is given in
DE 199 11 034 which discloses a ring holder made of two parts, one part of the ring containing
the transponder that is a separate part from the rings. More specifically, the ring
is made of two identical parts (half-rings) that can be fitted together. Each half
ring comprises a projecting part that is intended to penetrate into a corresponding
slot part of the bottle for attachment of the ring to the bottle (a slot that usually
does not exist on such bottles). This implies the machining of such a slot on the
bottle to meet this condition. For mounting the assembly on a bottle, the transponder
is placed in a chamber of one of the half-rings and these parts are placed on a bottle
in the desired position. The second half ring is brought laterally and attached to
the first half ring. This mounting procedure is quite complicated with at lest three
parts (two half rings and a transponder), the machining of a slot and also is not
easy to carry out since the antenna is not always protected. In addition, the first
half ring placed on the bottle must be maintained in position while the second half
ring is being attached.
[0011] A problem one is confronted with, especially with such gas bottles and cylinders
is to find away to place the tag in a protected position on the bottle/cylinder and
to dispose of a fixing methodology that allows to equip gas cylinder park that often
consist of several 100'000 or several millions of cylinders in an economically feasible
way.
[0012] Another problem is once one is able to tag in a quick and easy way such cylinders
to ensure that the tag remains into its position and cannot be removed without destruction.
SUMMARY OF THE INVENTION
[0013] The aim of the present invention is therefore to propose an improved tag fixation
system and tagging method with respect to the prior art.
[0014] More particularly, an aim of the present invention is to propose a tag system and
method that is simple, efficient and easy to apply while resisting to all environmental
and mechanical solicitation of several decades of the filed use of gas cylinders.
[0015] According to the invention, the tag system comprises a main ring that contains a
tag (for example a RFID tag) and that is placed on the gas bottle or cylinder, preferably
around a neck or flange of the bottle (in the case of industrial bottles, the standard
flange on which the protection cap is screwed as shown in Fig. 1, part 3), and a blocking
ring that is force fitted between the gas bottle or cylinder and the main ring. This
assembly results in a tag readable from 360 degres that is securely fitted to the
bottle or cylinder in a very simple manner and that can not be taken away without
violence respectively destruction of the tag, a further safety feature.
[0016] The invention will be better understood from the following description of different
embodiments and from the appended illustrative drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017]
Figure 1 shows a gas bottle/cylinder as used with the present invention;
Figure 2 illustrates an embodiment of the tag system according to the invention;
Figure 3 illustrates a detail of a side of a blocking ring according to the invention.
DETAILED DESCRIPTION
[0018] In figure 1, as typical gas bottle/cylinder is illustrated. This bottle/cylinder
comprises a body 1 (with a general cylindrical shape) with a cylinder dome (also called
shoulder) part 2. Said top part 2 comprises a neck or standardized flange 3 which
on a part of it, comprises a thread 4 (for screwing a valve cover (not shown). As
is usual in the art, the valve 5 comprises an outlet 6 for the gas.
[0019] According to the invention, the system is preferably mounted directly on the flange
3 (which is illustrated with dashed lines in figure 2) of the bottle in order to avoid
problems when mounting the valve cover. This in particular allows to avoid the problems
mentioned in
GB 2 288 103 where the tag cannot be read anymore without additional transmission means when the
cover is in place. According to the invention, the tag system comprises a main ring
10 that carries the tag, typically a 360° RFID tag which is overmoulded by the main
ring and thereby protected from mechanical and environmental wear. Preferably, the
tag and the antenna are embedded into said ring 10 for ease of manipulation.
[0020] Said main ring 10 is introduced over the valve 5 of the bottle 1 until it rests against
the top part 2 of the gas bottle/cylinder 1 on its standardized flange (part 3). The
main ring has a sufficient internal diameter for being easily slid over the said flange.
This flange, although standardized, has a manufacturing tolerance in diameter up to
several mm and may comprise numerous successive paint layers also contributing to
a larger diameter by several millimetres.
[0021] Considering the bottle of figure 1, the ring 10 is thus around the flange 3.
[0022] The ring further comprises a set of small steps 11 that are distributed inside its
main opening 12. Preferably, the inner sides of this opening 12 are of a hollow profile
as will be explained in more detail below.
[0023] Then a blocking ring 13 is used to block the main ring 10 in position on the bottle/cylinder.
The blocking ring 13 also comprises a set of steps 14 (see the detail illustrated
in figure 3) that are designed to force fit with the steps 11 of the main ring 10.
Preferably, the steps 11 of the main ring 10 a re similar to the steps 14 of the blocking
ring 13.
[0024] This blocking ring is equipped with one or several vertical openings or slots (part
15) whose depth may arise to 90% of the blocking ring's height, slots that induce
the flexibility of the blocking ring to cope with different cylinder flange diameters.
[0025] Due to the fact that the blocking ring has a vertical conicity, this flexibility
is applied to the thinner part of the blocking ring.
[0026] The fixation of the blocking ring, and of both rings on the bottle/cylinder, is made
by force-fitting the blocking ring 13 between the main ring 10 and the external surface
of the flange 3. The steps 11 and 14 then blockingly cooperate together making both
rings tightly fixed to the flange 3 of the bottle 1.
[0027] The slots 15 are used to compensate tolerances of the diameter of the flanges 3 of
different bottles/cylinders, in case of presence of paint, difference of size etc.
There can be one ore more such slots 15.
[0028] The advantage of the system of the present invention are the following:
-) pure mechanical mounting with no additional parts or particular tools needed (screws,
rivets, glue, etc.);
-) although not being a system with mechanical fixation, it copes with different cylinder
flange diameters (as caused by the mechanical tolerances of the cylinder flange and
a more or less numerous paint layers with different thicknesses)
-) the first ring is always in the same position since it bears against the cylinder
shoulder and therefore provides more security against abusive action;
-) long term fixation, that survives all cylinder working conditions;
-) easy and quick procedure with only two parts;
-) safety feature in that to remove a tag, it must be destroyed.
-) readability of an RFID tag on 360 degree around the cylinder flange.
[0029] Of course, the embodiment described is only one possible way of realising the invention
and other equivalent ways are possible. For example, the position of the rings could
be inverted, with the blocking ring placed first on the flange of the bottle then
the main ring being force-fitted over the blocking ring. In this embodiment, the blocking
ring 13 should be the other way round with respect to its illustration of figure 2
and underneath the main ring 10. Also the flaring of the steps 11 should be inverted
with respect to the representation of figure 2 to take account of the position of
the blocking ring.
[0030] The rings 10, 13 are preferably made of flame proof and UV resistant materials such
as Polyamid reinforced with glass or other fibers. Of course any other equivalent
materials may be envisaged.
[0031] Also, equivalent shapes other than steps 11, 14 may be used, such as flanges, lips,
threads etc. In addition even if not necessary, a glueing step or other equivalent
step may be carried out between the rings.
[0032] As one will understand, the examples given in the present description are purely
illustrative and should not be construed as limiting the scope of the invention.
1. A support for a tag, such as a RFID tag, for marking gas bottles or cylinders (1)
with a standardized flange (3), wherein said support comprises a main ring (10) containing
the tag and intended to be mounted on said flange (3) and a blocking ring that is
force-fitted between said flange (3) and said main ring (10).
2. A support as defined in claim 1, wherein said main ring (10) comprises steps (11)
having a particular form for forming a force fit connection with the corresponding
steps (14) on said blocking ring (13).
3. A support as defined in claim 1 or 2, wherein the zone of the main ring (10) comprising
the steps (11) is of a hollow profile for lodging a 360 degree tag antenna or other
RFID tag.
4. A support as defined in one of the preceding claims wherein the blocking ring comprises
at least one vertical slot (15).
5. A support according to one of the preceding claims, wherein the main ring (10) is
placed first on the flange (3) of the bottle (1) and then the blocking ring is force
fitted between the flange (3) and the main ring (10).
6. A support as defined in one of claims 1 to 4, wherein the blocking ring (13) is placed
first on the flange (3) of the bottle (1) and then the main ring (10) is force fitted
over the blocking ring (13).
7. A method of marking a gas bottle/cylinder with a tag wherein a first ring is placed
on the flange of a bottle, then a second ring is placed by force-fitting to attach
the assemble of ring on said bottle/cylinder.
8. A method as defined in claim 7, wherein the first ring is a main ring carrying the
tag and the second ring is a blocking ring.
9. A method as defined in claim 7, wherein the first ring is a blocking ring and the
second ring is a ring carrying the tag.