U.S. patent application number 12/520532 was filed with the patent office on 2010-05-06 for smoking article filter.
Invention is credited to Martin Graham Duke.
Application Number | 20100108085 12/520532 |
Document ID | / |
Family ID | 37758981 |
Filed Date | 2010-05-06 |
United States Patent
Application |
20100108085 |
Kind Code |
A1 |
Duke; Martin Graham |
May 6, 2010 |
Smoking Article Filter
Abstract
A filter for a smoking article comprising first and second
sections, the first section being at the mouth end of the filter
and comprising a cylindrical element circumscribed by a wrapper and
having a hollow portion extending therethrough, and the second
section being longitudinally aligned with and adjacent to the first
section and comprising a filtration material. The second section
comprises a particulate material in a circumferential region and
extending to the end of the second section immediately adjacent the
first section. Also provided is a smoking article incorporating a
filter according to the invention.
Inventors: |
Duke; Martin Graham;
(Millbrook, GB) |
Correspondence
Address: |
CHADBOURNE & PARKE LLP
30 ROCKEFELLER PLAZA
NEW YORK
NY
10112
US
|
Family ID: |
37758981 |
Appl. No.: |
12/520532 |
Filed: |
November 20, 2007 |
PCT Filed: |
November 20, 2007 |
PCT NO: |
PCT/GB07/04435 |
371 Date: |
December 7, 2009 |
Current U.S.
Class: |
131/339 |
Current CPC
Class: |
A24D 3/163 20130101;
A24D 3/048 20130101; A24D 3/04 20130101 |
Class at
Publication: |
131/339 |
International
Class: |
A24D 3/04 20060101
A24D003/04 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 21, 2006 |
GB |
0625818.0 |
Claims
1. A filter for a smoking article comprising a first and a second
section, the first section being at a mouth end of the filter and
comprising a cylindrical element having a hollow portion extending
therethrough and being circumscribed by a wrapper, and the second
section being longitudinally aligned with and adjacent to the first
section and comprising a filtration material, wherein the second
section comprises a particulate material in a circumferential
region thereof, the particulate material extending to an end of the
second section immediately adjacent the first section.
2. The filter according to claim 1, wherein the particulate
material extends over a full longitudinal length of the second
section.
3. The filter according to claim 1, wherein two or more portions of
the circumferential region of the second section comprise
particulate material.
4. The filter according to claim 3, wherein the two or more
portions are spaced circumferentially from one another.
5. The filter according to claim 4, wherein the two or more
portions are arranged symmetrically around the second section.
6. The filter according to claim 1, wherein a wrapper surrounds the
second section and the particulate material is adhered to a surface
of the wrapper.
7. The filter according to claim 6, wherein the particulate
material is adhered to an inner surface of the wrapper surrounding
the second section.
8. The filter according to claim 1, wherein the particulate
material is an adsorbent.
9. The filter according to claim 8, wherein the particulate
material is activated carbon.
10. The filter according to claim 1, wherein the second section
further comprises a particulate material interspersed in the
filtration material.
11. The filter according to claim 1, wherein the cylindrical
element has a wall defined by the outer surface of the element and
the hollow portion extending therethrough, the wall being of a
thickness to at least partly occlude the particulate material in a
circumferential region of the second section at the point of
abutment of the first and second sections.
12. The filter according to claim 1, wherein the wrapper
circumscribing the first section is a plugwrap.
13. The filter according to claim 12, wherein the plugwrap has a
base weight of less than 50 g/m.sup.2.
14. The filter according to claim 1, wherein the cylindrical
element of the first section comprises cellulose acetate.
15. The filter according to claim 1, further comprising at least
one additional filter section at the tobacco rod end of the
filter.
16. The filter according to claim 1 wherein two or more portions of
the circumferential region of the second section comprise
particulate material, and the two or more portions are spaced
circumferentially from one another, wherein a wrapper surrounds the
second section and the particulate material is adhered to a surface
of the wrapper, and the particulate material is adhered to an inner
surface of the wrapper surrounding the second section.
17. The filter according to claim 1 configured as a component
within a smoking article.
Description
[0001] The present invention relates to a filter for a smoking
article and smoking articles incorporating a filter element.
[0002] Smoking articles, and filters therefore, can vary
significantly from one market to another as a result of many
different factors including consumer preference and tradition. In
certain markets there is a preference for a filter having a recess
at the mouth end, which may be used to lengthen the filter as a
whole. The recess is achieved by overwrapping the plug of
filtration material with a plugwrap that extends beyond the end of
the plug of filtration material at the mouth end of the filter. In
order to minimise the susceptibility of the overhanging portion of
the plugwrap to damage and deformation, for example as may result
from the packaging process or during handling and smoking by a
consumer, a plugwrap which is thicker than a conventional cigarette
plugwrap is used. Such a plugwrap has up to four times the base
weight of a conventional plugwrap and thus is significantly more
resistant to deformation and adds a high level of rigidity at the
mouth end of the filter. However, the need for such a thick
plugwrap means that conventional (more economical) plugwraps cannot
be used on filters having a recessed end and also add significant
problems to the process of ventilating the filter, and in
particular to the process of online laser perforation of the
filter, thus not allowing high levels of ventilation to be
attained.
[0003] Various known filter arrangements are disclosed in
GB2203324; GB2170695; GB 2150415; GB 2150413; GB 2135865; GB
0781654; WO 99/65343 and U.S. Pat. No. 3,396,733.
[0004] The present invention provides a filter for a smoking
article comprising a first and a second section, the first section
being at a mouth end of the filter and comprising a cylindrical
element having a hollow portion extending therethrough and being
circumscribed by a wrapper, and the second section being
longitudinally aligned with and adjacent to the first section and
comprising a filtration material. The second section comprises a
particulate material in a circumferential region thereof, the
particulate material extending to the end of the second section
immediately adjacent the first section.
[0005] The use of particulate materials, such as carbon or
activated carbon, in tobacco smoke filter elements to reduce vapour
phase constituents of smoke has been known for some while. A known
way of including carbon or other additives in filters is to adhere
particles of the additive to a wrapper surrounding the filter
element. GB 2,260,477 and GB 2,261,152 describe various
configurations of additive adhesion. In some circumstances,
particulate carbon, when provided in a mouth end filter section,
may be liable to fall out of the end of the filter. This is highly
undesirable as it is possible that particulate carbon may become
loose and enter the mouth of the consumer. The provision of a first
filter section at the mouth end of the filter having a hollow
portion extending therethrough helps to prevent the fall out of the
particulate material whilst maintaining the appearance of a
recessed filter.
[0006] The particulate material may extend over the full
longitudinal length of the second section. The particulate material
may also extend over the full width of the wrapper. In this
instance the particulate material may cover the entire surface of
the wrapper, although a seam may be left uncovered to allow
adhesive to be applied and the wrapper to be sealed about the
filtration material. Alternatively, the particulate material may
extend over only a portion of the longitudinal length of the
wrapper. Similarly, the particulate material may extend over only a
portion of the width of the wrapper.
[0007] The particulate material may extend over two or more
portions of the second section. The two or more portions are
preferably spaced circumferentially from one another.
[0008] Alternatively, the two or more portions may comprise three,
four, five, six, seven or eight portions.
[0009] In some embodiments, the filtration material of the second
section may further comprise a particulate material interspersed in
the filtration material.
[0010] The particulate material of the filtration material may be
the same as the particulate material provided at the
circumferential region of the second section of the plugwrap.
Alternatively, the particulate material of the filtration material
may be different from the particulate material provided at the
circumferential region of the second section of the plugwrap.
[0011] In some embodiments, the wrapper may further comprise
ventilation means. For example, the ventilation means may comprise
one or more ventilation holes provided in gaps between the two or
more portions.
[0012] The cylindrical element will generally have a thickness (in
the radial direction) sufficient to occlude at least part of the
particulate material. In other words, the cylindrical element acts
as a physical barrier located at the mouth end of the particulate
material to prevent the particular material from escaping from the
second section of the filter. The thickness of the cylindrical
element may be from 1-4 mm, and is preferably in the range 1-3
mm.
[0013] Suitably the cylindrical element is circumscribed by a
wrapper, which is preferably a plugwrap. This plugwrap may have a
base weight of less than 50 g/m.sup.2, less than 45 g/m.sup.2, less
than 40 g/m.sup.2, less than 35 g/m.sup.2, less than 30 g/m.sup.2.
This plugwrap may have a base weight equivalent to a conventional
plugwrap (wrapper), namely approximately 23 to approximately 27
g/m.sup.2.
[0014] A second aspect of the present invention provides a smoking
article comprising a filter according to the invention.
[0015] Preferably the particulate material includes sorbents (e.g.
selected from activated carbon, charcoal, silica gel, sepiolite,
alumina, ion exchange material etc.), pH modifiers (e.g. alkaline
materials such as Na.sub.2CO.sub.3, acidic materials), flavourants,
other solid additives and mixtures thereof.
[0016] Advantageously the particulate material is selected from a
group of relatively high surface area materials capable of
adsorbing smoke constituents without a high degree of specificity.
Suitable general adsorbents can be selected from the group
consisting of carbon, activated carbon, activated charcoal,
activated coconut carbon, activated coal-based carbon or charcoal,
zeolite, silica gel, meerschaum, aluminium oxide (activated or
not), carbonaceous resin or combinations thereof.
[0017] An example of a suitable coal-based charcoal is one made
from semi-anthracite coal with a density about 50% greater than
coconut-based charcoal (available from Calgon Carbon, Pittsburgh,
Pa., WA).
[0018] An example of a suitable carbonaceous resin is one derived
from the pyrolysis of sulphonated styrene-divinyl benzene, such as
Ambersorb 572 or Ambersorb 563 (available from Rohm and Haas). To
enhance the efficiency of the general adsorbent metal oxides or
other metal based complexes may optionally be included in or
impregnated on the general adsorbent section.
[0019] In one embodiment, preferably the particulate material used
herein is carbon, for instance activated carbon, or charcoal or
other absorbent material. In one embodiment, preferably the
activated carbon is activated coconut carbon.
[0020] Any particulate material used may be a single substance or a
mixture, and/or may be in admixture with other material.
[0021] In one embodiment preferably the particulate material is
disposed in two separate regions spaced circumferentially from one
another. Alternatively, the particulate material may be disposed in
3, 4, 5, 6, 7 or 8 separate regions each spaced circumferentially
from one another. Further, a greater number of regions may be used
if required.
[0022] Each separate region or portion of particulate material may
be comprised of particulate material which is the same as or
different from the other separate regions. In one embodiment
preferably the particulate material in the separate regions is the
same.
[0023] In one embodiment, suitably the particulate material may be
applied to two or more portions of the longitudinal inner face of
the wrapper.
[0024] In one embodiment the particulate material is disposed
around the inner circumference of the wrapper such that the wrapper
has an overlapping longitudinal edge which is free of said
particulate material and which provides a lapped and stuck seam
holding the wrapper around the core.
[0025] The particulate material may extend continuously over the
full longitudinal length of said wrapper. By continuously it is
meant that the particulate material is applied such that the
loading at any one point on the longitudinal length of the wrapper
is the same (or substantially the same) as the loading at any other
point on the same longitudinal length of the wrapper. By
continuously it is meant that at no point along the longitudinal
length of the wrapper is there a portion of the wrapper without
particulate material if the particulate material is present at
another point along the same longitudinal length of the wrapper.
Preferably, the particulate material is applied longitudinally to
the wrapper (e.g. plugwrap) in a continuous manner. Preferably
along the longitudinal axis of the wrapper the particulate material
is present as a continuous stream (i.e. without breaks or spaces).
In other words, the particulate material extends in a continuous
manner along the longitudinal axis of the wrapper.
[0026] The particulate material may extend continuously over the
full width of said wrapper.
[0027] In some embodiments the particulate material may be present
as patches.
[0028] The wrapper of the filter element is preferably a paper
wrapper. Preferably the wrapper is a conventional plugwrap.
[0029] In one embodiment the wrapper may be a conventional plugwrap
which covers 360.degree. of the core, in which case the plugwrap
has a lapped and stuck seam holding the wrapper around the
core.
[0030] In one embodiment, preferably the filter element according
to the present invention has a filtration material comprising
particulate material interspersed with the filtration material and
has a plugwrap which covers 360.degree. of the filtration
material.
[0031] In another embodiment the wrapper (in particular plugwrap)
preferably does not extend 360.degree. around the filtration
material. In other words, in one embodiment preferably the wrapper
is a split wrapper. A split wrapper is one which extends
circumferentially about the filtration material, but extends less
than 360.degree. around the circumference of the filtration
material. In such an embodiment, there is not lapped and stuck seam
holding the wrapper around the filtration material. Instead, the
split wrapper may be held in place by other known means, such as by
bonding the wrapper directly to the filtration material for
instance.
[0032] The wrapper for use in the filter element may be porous or
non-porous.
[0033] The wrapper for use in the filter element may be ventilated
or unventilated.
[0034] Advantageously the filtration material of the second section
may comprise (or consist of) conventional fibrous cellulose
acetate, polypropylene or polyethylene material or gathered paper
material.
[0035] Preferably the filtration material comprises cellulose
acetate.
[0036] In one embodiment, the filtration material of the second
section is a Dalmatian-type filter material.
[0037] The particulate material may be interspersed throughout the
filtration material. Alternatively, the particulate material may be
interspersed in some parts (but not all) of the filtration
material. The parts may be evenly or unevenly distributed.
[0038] The particulate material adhered to the wrapper may be
homogenous--in the sense that it is made up of substantially the
same component (for some embodiments, preferably all of the same).
Alternatively, the particulate material adhered to the wrapper may
be heterogeneous--in the sense that it is made up of two or more
different components. The particulate material adhered to the
wrapper may be in contact with the filtration material. Preferably,
some or all of the particulate material adhered to the wrapper is
in contact with the filtration material. For some embodiments,
preferably substantially all of the particulate material adhered to
the wrapper is in contact with the filtration material.
[0039] The filter is preferably interattached with a smokable
filler (e.g. tobacco) rod by way of a tipping wrapper.
Advantageously the tipping wrapper is a paper.
[0040] In one embodiment the filter may comprise additional filter
section(s). The additional filter section(s) will be at the tobacco
rod end of the filter. Suitably, one, two, three or more additional
filter sections may be provided in the filter. The additional
filter section(s) may be any type of filter section known to those
skilled in the art. Suitably the filter sections are arranged
longitudinally of one another with the end of each filter element
abutting the next.
[0041] Suitably the wrapper surrounding the second section of the
filter is preferably pre-coated with the particulate material.
[0042] The particulate material may be adhered to the wrapper by
hot melt adhesive (e.g. various polyester adhesives), high m.p.
polyethylene glycol, or emulsion-type adhesive such as PVA.
[0043] The particulate material may be directly or indirectly
adhered to the wrapper. An example of direct adherence is wherein
the particulate material is affixed to the wrapper (such as the
inner surface thereof) by means of a suitable adhesive. An example
of indirect adherence is wherein the particulate material is
affixed to an intermediate layer (which may be made of paper or
other suitable support matrix--such as a textile material--or
combinations thereof) by means of a suitable adhesive and wherein
the intermediate layer is affixed to the wrapper (such as the inner
surface thereof) by means of a suitable adhesive.
[0044] Suitably the additional filter section(s) of the filter may
be comprised of conventional fibrous cellulose acetate,
polypropylene or polyethylene material or gathered paper material.
The additional filter section(s) may optionally comprise one or
more additives, for instance disposed upon or within the material
of the filter element may be further flavouring materials, as
described above, which are released or eluted from the filter
element during use.
[0045] The cylindrical element of the first section at the mouth
end may be made from a variety of materials, for example, cellulose
acetate tow, cellulose, paper, cotton, polypropylene web,
polypropylene tow, polyester web, polyester tow or combinations
thereof. It is preferred that the element comprises cellulose
acetate.
[0046] In addition, the pressure drop and/or mechanical filtration
efficiency of the filter sections can be selected to achieve the
desired smoking mechanics and filtration characteristics as may be
required with the specific product design desired.
[0047] A part of the filter may comprise a catalyst. Advantageously
the catalyst facilitates the conversion of carbon monoxide (CO) to
carbon dioxide (CO.sub.2) in the vapour phase of the smoke. It is
much by preference that the catalyst is highly selective for carbon
monoxide. Suitably the catalyst may be one of the group consisting
of transition metal oxides, silica, alumina, zeolites, impregnated
carbon, for example, carbon impregnated with metals.
[0048] Suitably the filter and/or smoking article according to the
present invention may comprise ventilation means. For example, the
ventilation means may comprise one or more holes in the wrapper
engaged around the filtration material of the second section. The
holes may advantageously be positioned in regions of the wrapper to
which the particulate material is not adhered. Ventilation holes
are often formed in filter wrappers by laser piercing. Carbon
granules in the region where ventilation is required can cause the
laser to produce sparks when the holes are being made. Positioning
the ventilation holes in gaps between the portions of particulate
material addresses this problem.
[0049] The ventilation means may comprise perforation holes in the
tipping wrapper used to interattach the filter and the rod of
wrapped smokable filler (e.g. tobacco) material.
[0050] Alternatively the ventilation means may be provided by the
use of a porous tipping wrapper used in conjunction with a
perforated plugwrap. The porous tipping wrapper may be porous over
its full extent or over only a localised extent, which extent is in
registration with the underlying perforated plugwrap.
[0051] The ventilation means may further be provided at or close to
the end of the rod of wrapped smokable filler (e.g. tobacco)
material. The ventilation means may be provided in the tipping
wrapper or in the cigarette paper wrapper enwrapping the smokable
filler (e.g. tobacco) material.
[0052] Suitably, the filter may be attached to a wrapped smokable
filler material rod (i.e. a wrapped tobacco rod for instance) by
conventional tipping overwrap to form a smoking article. The
tipping overwrap may be ventilating or non-ventilating
overwrap.
[0053] The length of the smoking material rod is advantageously at
least 60 mm and the rod should preferably yield not less than six
puffs, and more preferably not less than seven puffs when smoked
under standard machine smoking conditions. The rod is preferably of
uniform cross-sectional shape and dimensions throughout the length
of the rod.
[0054] The wrapper enwrapping the smoking article may comprise a
burn additive, such as sodium and/or potassium citrate, for
example. Other suitable burn additives, such as sodium or potassium
salts, such as acetate and tartrate; mono-ammonium phosphate, and
di-sodium hydrogen phosphate, for example, will be known to the
skilled man. The burn additive may be present in the range of
0.5-2.5% by weight of the wrapper. The wrapper may also have a base
weight in the range of 20-40 g/m.sup.2.
[0055] The wrapper of the smoking article may alternatively or in
addition be a non-paper wrapper, such as the wrappers described in
International Patent Applications, Publications Nos. WO 96/07336
and WO 01/41590. Such wrappers assist in the reduction of
sidestream smoke components, but still provide a smoking article
which has burning and ashing characteristics similar to
conventional products, i.e. the wrappers allow the smoking article
to burn down and ash in a similar way to conventional products.
[0056] Suitably, the smokable filler material may be
tobacco-containing material or a tobacco substitute material.
Preferably the smokable material is a tobacco material. Suitably
the tobacco material comprises one or more of stem, lamina, tobacco
dust and reconstituted tobacco. It is preferred that the tobacco
material comprises one or more of the following types: Virginia or
flue-cured tobacco, Burley tobacco, Oriental tobacco, reconstituted
tobacco. It is much by preference that the smokable material
comprises a blend of tobacco material. Advantageously the smokable
material comprises 10-80% Virginia tobacco, 10-60% Burley tobacco,
0-20% Oriental tobacco, 0-120% reconstituted tobacco and 0-30%
expanded tobacco.
[0057] The term `carbon` as used herein can be taken to cover a
material which is substantially solely carbon and any carbon
precursors, such as carbonaceous material. As used herein the term
carbonaceous includes material which has been pyrolysed, which
material preferably contains carbon, although some incomplete
combustion products may still be present. Ready pyrolysed coconut
fibre may, for example, be the carbonaceous material from which
carbon is derived.
[0058] As used herein, the term `smoking material` or `smokable
filler material` means any material which can be used in a smoking
article. It does not necessarily mean that the material itself will
necessarily sustain combustion.
[0059] As used herein, the term `smoking article` means any product
that is used in the tobacco industry and includes smokable products
or similar products for delivering an aerosol to the consumer.
Smoking articles include cigarettes, cigars, cigarillos and similar
articles.
[0060] In order that the present invention may be clearly
understood and readily carried into effect reference will now be
made, by way of example, to the accompanying drawings in which:
[0061] FIG. 1 shows a longitudinal cross-sectional view of a filter
having a recess at the mouth end according to the prior art;
[0062] FIG. 2 shows a longitudinal cross-sectional view of a filter
according to one embodiment of the present invention;
[0063] FIG. 3 shows an end view from the mouth end of a filter
according to one embodiment of the present invention;
[0064] FIG. 4 shows a longitudinal cross-sectional view of a filter
according to a further embodiment of the present invention; and
[0065] FIG. 5 shows a longitudinal cross-sectional view of a tilter
according to an alternative arrangement of the present
invention.
[0066] FIG. 1 shows a known filter 1 attached to a tobacco rod 2
(only a portion of which is shown) to form a cigarette. Filter 1
consists of a plug of cellulose acetate 3 (filtration material)
circumscribed by a plugwrap 4. The plugwrap 4 is longer than the
plug of cellulose acetate 3 and overhangs the plug of cellulose
acetate at the mouth end of the filter 1 to create a recess having
a depth typically of approximately 5 mm. The length of overhang of
the plugwrap 4 is designated in FIG. 1 by the reference character
x. The filter 1 is attached to the tobacco rod by a tipping wrapper
5 in the conventional manner. The plugwrap 4 is typically a wrapper
having a high base weight, for example 100 g/m.sup.2 to provide
rigidity to the filter 1.
[0067] FIG. 2 shows a filter 1 in accordance with the present
invention in which a first section at the mouth end of the filter 1
comprises a tubular plug of cellulose acetate 6 having a hollow
central core, designated by reference numeral 7 in FIG. 2. The
filter 1 also consists of a second section at the tobacco rod end
of the filter 1 and adjacent the first section. The second section
comprises a plug of cellulose acetate filtration material 3
circumscribed by a plugwrap 4, which plugwrap 4 may also
circumscribe the cellulose acetate plug 6 of the first section.
Alternatively the plugs 3, 6 may each be circumscribed by a
respective individual plugwrap. The filter 1 is attached to a
tobacco rod 2 to form a cigarette by a standard tipping wrapper 5.
The plugwrap 4 and/or the tipping wrapper 5 may be ventilated (not
shown) at any point over their surface and to a varying amount
dependent on the particular product. The plug of cellulose acetate
6 of the first filter section may for instance be 7 mm in length
and provides rigidity to the mouth end of the filter 1 and allows a
conventional plugwrap 4 to be used without reducing strength.
[0068] FIG. 3 shows the filter of FIG. 2 in end view from the mouth
end thereof. The cylindrical plug of cellulose acetate 6 defines a
hollow core 7 longitudinally along the centre of the plug 6. The
plug of cellulose acetate filtration material 3 of the second
section can be seen at the far end of the hollow core 7. The
thickness of the cylindrical plug of cellulose acetate 6 is defined
by the outer surface of the plug 9 and by the inner surface of the
plug 8. This thickness, designated by reference character z in FIG.
3, may vary depending on the desired size of the recess at the
mouth end of the filter 1. The cylindrical plug of cellulose
acetate 6 is circumscribed by a plugwrap (not shown) and is
surrounded by a tipping wrapper (not shown) to join the filter 1 to
a tobacco rod in a formed cigarette. The inner-surface of the plug
of the first filter section may be of any desired shape and thus
serve to create a recognizable shape for the hollow core 7.
[0069] The filter 1 of FIG. 4 comprises all of the features of FIG.
2, and same reference numerals are used to denote equivalent
features, with the addition of a particulate activated carbon 10
adhered to the inner surface of the plugwrap 4 circumscribing the
plug of cellulose acetate 3 of the second filter section. The
carbon 10 extends the entire longitudinal length of the second
section, being for instance 20 mm in length. The thickness of the
wall of the plug of cellulose acetate of the first filter section
is sufficient to cover the carbon at the position of abutment
between the first and second filter sections and prevent any carbon
10 becoming loose and escaping into the first filter section or
beyond the mouth end of the filter 1.
[0070] FIG. 5 shows a filter 1 which comprises all of the features
of FIG. 4, with the alteration in the length of the layer of carbon
10. Particulate activated carbon 10 extends over only a portion of
the plugwrap 4 which circumscribes the plug of cellulose acetate 3
of the second filter section. The carbon 10 extends from the end of
the plug of cellulose acetate 3 nearest the mouth end of the filter
1 to a position part way along the plug 3 towards the tobacco rod
2.
[0071] All publications mentioned in the above specification are
herein incorporated by reference. Also included herein by reference
is our co-pending UK patent application filed on 6 Jul. 2006 and
having application number 0613483. Various modifications and
variations of the described methods and system of the present
invention will be apparent to those skilled in the art without
departing from the scope of the present invention. Although the
present invention has been described in connection with specific
preferred embodiments, it should be understood that the invention
as claimed should not be unduly limited to such specific
embodiments. Indeed, various modifications of the described modes
for carrying out the invention which are obvious to those skilled
in the art are intended to be within the scope of the following
claims.
* * * * *