[0001] This invention relates to a unit and a method for measuring the pressure drop in
a smoking article.
[0002] In particular, the term "smoking article" is used herein to denote any rod-shaped
article for the tobacco industry, defining a finished product, such as a cigarette,
for example, or a semi-product (for example: a filter segment, a tobacco segment,
a composite segment or a piece of a multisegment product).
[0003] The cigarette may be a traditional cigarette which can be smoked by burning the end
of the tobacco segment defining the active portion, or inhaled by heating but not
burning an active portion.
[0004] Thus, the active portion may be a cigarette segment comprising traditional tobacco
or it may be an aerosol-generating element, that is, a product containing heat-not-burn
type tobacco.
[0005] In order to be correctly smokable, cigarettes must be easy to inhale and draw pressure
must be such that inhalation is smooth and not excessively intense.
[0006] To ensure they provide optimum smoking pleasure, cigarettes are therefore subjected
to specific tests to make certain that the pressure drop within the smoking articles
falls within specified ranges of acceptability.
[0007] That way, it is possible to determine whether the properties of the smoking articles
made are such that the smokability of the cigarette is acceptable - that is, that
they allow the cigarette to be correctly inhaled - based on predetermined parameters.
[0008] For traditional cigarettes, it is established practice in the tobacco industry to
test the smoking articles in line after they have been made and to measure the value
of the pressure drop, also known as "resistance to draw" (RTD) by making air flow
through the smoking articles at a predetermined rate and recording the resulting overpressure
on the side on which the air stream is applied.
[0009] Measurement is performed typically in the machine while the articles move transversely
along their feed path on conveyors.
[0010] For example, the smoking articles disposed inside suction housing seats round the
periphery of a transfer drum are made to pass by a detection device located at a fixed
position on the drum itself.
[0011] As the drum rotates, each article moves past the detection device in such a way that
the end of the article is aligned with an angular loading slot of the detection device
which extends along a circular arc and through which a predetermined amount of air
is injected. This solution is described, for example, in
DE3341686 (slots 24 and 31) or
US3418844 (slots 96-112). More specifically, the angular extent of the loading slot is smaller
than the angular distance between two consecutive smoking articles to allow only one
smoking article at a time to be loaded and hence tested.
[0012] Once air has been loaded into the article, a pressure sensor of the detection device
measures the RTD value.
[0013] The article is thus loaded with air for a loading time corresponding to the time
taken by the article to travel in front of the angular loading slot. Thus, under equal
conditions of air flow injectable into the article and of drum rotation speed, the
greater the angular length of the slot, the greater the quantity of air that can be
injected into the article.
[0014] More specifically, the higher the RTD, the longer the time needed for the pressure
to be stabilized and thus, for smoking articles with high RTD, air must be injected
for a longer length of time. Conversely, the higher the article production speed (that
is, the higher the drum rotation speed) the less the time available for supplying
the air, since the articles are tested while in motion.
[0015] In practice, this translates as a limitation on the maximum RTD value measurable
by the detection device. In effect, at the end of the test, the higher the real RTD
value is, the more it will differ from the RTD reading of the sensor.
[0016] The Applicant has thus found that to obtain an acceptable measurement for smoking
articles with a high RTD value in prior art machines, it is necessary to provide longer
loading slots or to reduce the production speed; both solutions have considerable
disadvantages, however.
[0017] In effect, if the slots were to be made longer, the quantity of air loaded by each
would be divided between two or more consecutive articles, thus losing control over
how much air is actually injected into each article and altering the measurement performed
by the pressure sensor.
[0018] If rotation speed is lowered, on the other hand, production efficiency is reduced,
with evident disadvantages in terms of productivity.
[0019] The purpose of this invention is to provide a unit and a method for measuring the
pressure drop in a smoking article to allow increasing the maximum measurable RTD
value.
[0020] More specifically, this invention has for an aim to increase the length of time available
for injecting air through the smoking articles without reducing the production speed.
The maximum measurable RTD value is thus increased, making it possible to measure
a wide range of smoking articles.
[0021] The technical purpose indicated and the aims specified are substantially achieved
by a unit and a method for measuring the pressure drop in a smoking article, comprising
the technical features described in one or more of the appended claims.
[0022] More specifically, this invention provides a unit for measuring the pressure drop
in a smoking article, comprising:
- a conveyor comprising a plurality of housing seats configured to receive and transversely
feed a plurality of rod-shaped smoking articles along a feed path,
- a fixed measuring device disposed on the feed path and configured to measure a value
of pressure drop in each article, wherein the measuring device comprises at least
one air loading slot connected or connectable to a compressed air source,
- connecting means disposed on the conveyor and configured to connect the air loading
slot sequentially to one of the housing seats in order to feed an air flow to the
articles.
[0023] Advantageously, the measuring device comprises at least two air loading slots connected
or connectable to respective, distinct compressed air sources and the connecting means
are configured to alternately connect consecutive housing seats to different air loading
slots.
[0024] That way, supplying the air flow to one article does not interfere with the supplying
of the air flow to the next adjacent article since the loading slots are connected
to distinct compressed air sources and it is therefore possible to increase the air
loading time.
[0025] In other words, thanks to this invention, under equal conditions (given a certain
spacing between the articles, a certain feed speed and a given air supply flow rate),
it is possible to create loading slots that are longer than in the prior art, using
the alternate connection of consecutive articles to distinct loading slots.
[0026] This invention also provides a method for measuring the pressure drop in a smoking
article, comprising the following steps:
- transversely feeding a plurality of rod-shaped smoking articles along a feed path
through a fixed measuring device, where the measuring device comprising at least one
air loading slot connected to a compressed air source,
- placing one end of each smoking article in fluid communication with the at least one
air loading slot;
- measuring the value of pressure drop of each article connected to the air loading
slot.
[0027] Advantageously, the measuring device comprises two air loading slots connected or
connectable to distinct compressed air sources and the step of measuring the value
of pressure drop of each article is performed by alternately connecting the ends of
consecutive articles to different air loading slots.
[0028] The alternate connection of the ends of consecutive articles to different air loading
slots makes it possible to increase the pressure drop measuring efficiency, with high
RTD values, to obtain measurements that are as close as possible to the real values.
[0029] The dependent claims, which are incorporated herein by reference, correspond to different
embodiments of the invention.
[0030] Further features of the invention and its advantages are more apparent in the non-limiting
description below, with reference to a preferred but non-exclusive embodiment of a
unit for measuring the pressure drop in a smoking article, as illustrated in the accompanying
drawings, in which:
- Figure 1 is a perspective view of a unit for measuring the pressure drop in a smoking
article according to this invention;
- Figure 2 is a top view of the unit of Figure 1;
- Figure 3 is a front view of a part of a conveyor of a unit for measuring the pressure
drop in a smoking article according to this invention;
- Figure 4 is a front view of a detail of a first embodiment of a measuring device of
a unit for measuring the pressure drop in a smoking article according to this invention;
- Figures 4A-4D schematically illustrate a sequence of operating steps of a unit for
measuring the pressure drop in a smoking article according to the first embodiment
of the measuring device of Figure 4;
- Figure 5 is a front view of a detail of a second embodiment of a measuring device
of a unit for measuring the pressure drop in a smoking article according to this invention;
and
- Figures 5A-5D schematically illustrate a sequence of operating steps of a unit for
measuring the pressure drop in a smoking article according to the first embodiment
of the measuring device of Figure 5.
[0031] With reference to the accompanying drawings, the numeral 1 denotes in its entirety
a unit for measuring the pressure drop in a smoking article, hereinafter referred
to simply as unit 1.
[0032] The unit 1 comprises a conveyor 2 comprising a plurality of housing seats 3, preferably
suction seats, configured to receive and transversely feed a plurality of rod-shaped
smoking articles 100 along a feed path P.
[0033] For convenience of illustration, Figures 1 and 2 show only one article 100. The unit
1 then comprises a fixed measuring device 4 disposed on the feed path P and configured
to measure a value of pressure drop in each article 100.
[0034] The articles 100 are thus movable relative to the measuring device 4. With reference
to Figures 4 and 5, the measuring device 4 comprises at least one air loading slot
5a, 5b connected or connectable to a compressed air source 6a, 6b.
[0035] The unit also comprises connecting means 7 disposed on the conveyor 2 and configured
to connect at least one air loading slot 5a, 5b sequentially to one of the housing
seats 3 in order to feed an air flow to the articles 100. Advantageously, according
to this invention, the measuring device 4 comprises at least two air loading slots
5a, 5b connected or connectable to respective, distinct compressed air sources 6a,
6b and the connecting means 7 are configured to alternately connect consecutive housing
seats 3 to different air loading slots 5a, 5b.
[0036] For example, with reference to Figure 4A, a first article 100a is adapted to be loaded
with a first air flow from the compressed air source 6a through the air loading slot
5a, while a second article 100b is adapted to be loaded with a second air flow from
the compressed air source 6b through the air loading slot 5b.
[0037] In other words, connecting the articles 100 selectively to alternately different
air loading slots 5a, 5b allows making longer air loading slots 5a, 5b, preferably
longer than the centre distance between one article 100 and the next without the loading
slot 5a, 5b loading more than one article 100 at a time.
[0038] Thanks to the selective connection of the articles 100a, 100b to respective alternate
loading slots 5a, 5b, it is thus possible to make loading slots 5a, 5b whose length
is such as to allow obtaining a true measurement of the pressure drop of articles
having high values of pressure drop (or resistance to draw, RTD): for example, higher
than 200 mmH2O.
[0039] Preferably, therefore, the loading slots 5a, 5b are at a fixed position on the measuring
device 4, whilst the connecting means 7 formed on the conveyor are movable along the
feed path P together with the articles 100.
[0040] It should be noted that in the embodiments illustrated, there are 2 loading slots
5a, 5b. However, solutions where the loading slots 5a, 5b are more than 2 in number
are also imaginable without departing from the scope of the inventive concept of this
invention.
[0041] The unit 1 is thus advantageously suitable for easy installation in any machine for
making smoking articles 100 in order to efficiently measure the pressure drop values
in the articles 100.
[0042] Moreover, with reference to the embodiments of this invention illustrated in the
accompanying drawings, the conveyor 2 is preferably a drum which rotates about an
axis of rotation X and has, for each housing seat 3, at least one supporting element
3' for an end portion of an article 100 housed in the housing seat 3.
[0043] The supporting elements 3' are advantageously configured to make a sealed compressed
air connection with the compressed air sources 6 in order to obtain a correct measurement.
[0044] More specifically, the supporting element 3' is associated with the connecting means
7 and the feed path P is a circular path.
[0045] As shown in Figure 2, the supporting elements 3' engage the ends of the articles
100 only at a measuring zone M located at the measuring device 4 to allow measuring
operations to be carried out. In the embodiment illustrated, the measuring zone M
is engaged by means of supporting elements 3' which are fixed to the drum 2 at external
inclined discs 2' that are configured to travel along a trajectory lying in a plane
transverse to the axis of rotation X of the drum 2. Alternatively, for example in
an embodiment not illustrated in the accompanying drawings, the supporting elements
3' might be movable towards and away from the articles 100 along the longitudinal
axes thereof so as to selectively engage the articles 100 at the measuring zone M.
[0046] Preferably, the two loading slots 5a, 5b extend along respective directions of extension
parallel to the feed path P of the articles 100 and run alongside each other in a
direction perpendicular to the feed path P. More specifically, as shown in the accompanying
drawings, therefore, the two loading slots 5a, 5b extend along arcuate directions.
[0047] With reference to Figure 3, the connecting means 7 preferably comprise, for each
housing seat 3, a respective connecting slot 7a, 7b configured to pneumatically connect
each article 100a, 100b to a respective air loading slot 5a, 5b. In particular, the
connecting slots 7a, 7b are disposed in at least two alternate sets in such a way
that consecutive housing seats 3a, 3b correspond to connecting slots 7a, 7b of distinct
sets configured to be connected to different air loading slots 5a, 5b.
[0048] For example, with reference to Figure 4A, a first article 100a, disposed in a first
housing seat 3a with which a first connecting slot 7a is associated, is adapted to
be loaded with a first air flow from the compressed air source 6a through a first
air loading slot 5a, while a second article 100b, disposed in a second housing seat
3b (downstream of the first housing seat 3a) with which a second connecting slot 7b
is associated, is adapted to be loaded with a second air flow from the compressed
air source 6b through a second air loading slot 5b.
[0049] Preferably, the connecting slots 7a, 7b extend between the respective article 100a,
100b and the respective air loading slot 5a, 5b along respective directions of extension
transverse, preferably perpendicular, to the feed path P.
[0050] Preferably, the measuring device 4 comprises, for each air loading slot 5a, 5b, a
respective measuring slot 8a, 8b which is juxtaposed with the respective air loading
slot 5a, 5b.
[0051] Advantageously, inside each measuring slot 8a, 8b there is a pressure sensor configured
to measure a value of pressure drop associated with a respective article 100a, 100b.
More specifically, each measuring slot 8a, 8b is placed in fluid communication with
the respective air loading slot 5a, 5b by the connecting means 7.
[0052] Advantageously, therefore, the air is loaded into the articles 100 through the loading
slots 5a, 5b and measurement is performed through the measuring slots 8a, 8b.
[0053] Preferably, the measuring slots 8a, 8b extend along respective directions of extension
parallel to the feed path P of the articles 100.
[0054] Preferably, the measuring slots 8a, 8b are shorter in length, measured parallel to
the feed path P, than the loading slots 5a, 5b.
[0055] As clearly shown in Figures 4 and 5, the air loading slots 5a, 5b are interposed
between the measuring slots 8a, 8b relative to a direction transverse to the feed
path P.
[0056] With reference in particular to Figures 4A-4D and 5A-5D, it may also be noted that,
preferably, for an operating stretch of the feed path P (whose length or angular size
is preferably approximately half the length or angular size of the respective loading
slot 5a, 5b), the measuring slot 8a, 8b, the respective air loading slot 5a, 5b and
the respective article 100a, 100b to be measured are placed in mutual fluid communication
simultaneously by the connecting means 7.
[0057] Preferably, also, as illustrated in the accompanying drawings, the operating stretch
just mentioned coincides with the length of the measuring slot 8a, 8b.
[0058] As clearly shown in Figures 4 and 5, each measuring slot 8a, 8b preferably at least
partly overlaps the respective air loading slot 5a, 5b along the feed path P and,
still more preferably, overlaps only an end portion of the respective air loading
slot 5a, 5b along the feed path P so that the pressure is measured only when the article
100 is in communication with that end portion of the of the air loading slot 5a, 5b.
[0059] Preferably, the end portion of the air loading slot 5a, 5b referred to above extends
for a length that is approximately half the length of the air loading slot 5a, 5b
itself.
[0060] According to this invention, the conveyor 2 preferably comprises, for each housing
seat 3a, 3b, a respective vent 9a, 9b configured to intercept a respective measuring
slot 8a, 8b and to relieve the pressure in the measuring slot 8a, 8b. In particular,
the vents 9a, 9b are disposed on the conveyor 3 in at least two alternate sets in
such a way that consecutive vents 9a, 9b intercept different measuring slots 8a, 8b.
[0061] The vents 9a, 9b and the connecting slots 7a, 7b are thus disposed alternately on
the conveyor 3 at each housing seat 3a, 3b along the feed path P.
[0062] In particular, for each housing seat 3a, 3b, the respective vent 9a, 9b is disposed
on the side opposite to the respective connecting slot 7a, 7b so that when the connecting
slot 7a, 7b associated with the housing seat 3a, 3b is in communication with a respective
measuring slot 8a, 8b, the respective vent 9a, 9b is in communication with the other
measuring slot 8a, 8b.
[0063] In other terms, for each housing seat 3a, 3b, there is a connecting slot 7a, 7b on
a first side and a vent 9a, 9b on a second side and for the next housing seat 3a,
3b, the first and second sides are reversed.
[0064] Preferably, each vent 9a, 9b is aligned with the respective connecting slot 7a, 7b
transversely to the feed path P and, still more preferably, aligned along the direction
of extension of the connecting slot 7a, 7b.
[0065] With reference to the embodiment illustrated in Figures 5A-5D, the measuring device
4 advantageously comprises, for each air loading slot 5a, 5b, a respective air pre-loading
slot 10a, 10b disposed upstream of the air loading slot 5a, 5b relative to the feed
path P and connected or connectable to a respective compressed air source 6c, 6d distinct
from the compressed air source 6a, 6b of the respective air loading slot 5a, 5b.
[0066] More specifically, the connecting means 7 are configured to alternately connect at
least one air pre-loading slot 10a, 10b to one of the housing seats 3 and, still more
preferably, to connect consecutive housing seats 3a, 3b to different air pre-loading
slots 10a, 10b.
[0067] Advantageously, therefore, before being connected to the air loading slot 5a, 5b,
each article 100 is first connected to an air pre-loading slot 10a, 10b. Thanks to
the presence of the air pre-loading chambers 10a, 10b, it is possible increase the
length of time available to pressurize the article 100 and to allow high RTD values
to be measured efficiently.
[0068] Preferably, each air pre-loading slot 10a, 10b is aligned with the respective air
loading slot 5a, 5b in such a way that each article 100 is placed sequentially in
fluid communication, by the connecting means 7, first with an air pre-loading slot
10a, 10b and then with the respective air loading slot 5a, 5b.
[0069] That way, the overall length of the stretch along which each article 100 is loaded
with air is increased.
[0070] It should be noted that if the conveyor 2 is a drum, the air pre-loading slots 10a,
10b are preferably arcuate in extension along the feed path P. Preferably, each air
pre-loading slot 10a, 10b is greater than or equal to the respective air loading slot
5a, 5b in length.
[0071] It should be noted that the lengths of the air loading slots 5a, 5b and of the air
pre-loading slots 10a, 10b and their distances from each other are such that different
connecting slots 7a, 7b are never placed in pneumatic communication with each other.
[0072] Also part of this invention is a method for measuring the pressure drop in a smoking
article 100, comprising the following steps:
- transversely feeding a plurality of articles 100 along a feed path P through a fixed
measuring device 4, where the measuring device 4 comprises two air loading slots 5a,
5b connected or connectable to distinct compressed air sources 6a, 6b;
- placing one end of each smoking article 100 in fluid communication with the at least
one air loading slot 5a, 5b;
- measuring the value of pressure drop of each article 100 connected to the air loading
slot 5a, 5b by alternately connecting the ends of consecutive articles 100 to different
air loading slots 5a, 5b.
[0073] Preferably, the step of measuring the pressure drop of an article 100a, performed
while the article 100 is connected to the respective air loading slot 5a, is performed
simultaneously with a step of placing one end of the next consecutive article 100b
in fluid communication with a different air loading slot 5b.
[0074] Advantageously, air can be loaded into each article 100 for a longer length of time.
[0075] Preferably, also, the step of measuring a first article 100a starts simultaneously
with the starting of the step of placing one end of a second article 100b, following
the first article 100a, in fluid communication with a respective air loading slot
5b.
[0076] With reference to the accompanying drawings, the air loading slots 5a, 5b preferably
have the same extension, be it linear or angular, along the feed path P and wherein
the step of measuring the pressure drop of the first article 100 starts while the
end of the first article 100a is disposed at an end portion of the respective air
loading slot 5a, further downstream, so that the step of measuring the first article
100a starts substantially simultaneously with the starting of the step of placing
one end of a second article 100b in fluid communication with the respective air loading
slot 5b.
[0077] Preferably, also, the step of measuring is accomplished by connecting to each other
the end of the article 100 being measured, the air loading slot 5a, 5b and the measuring
slot 8a, 8b by means of a single connecting slot 7a, 7b which is movable as one with
the article 100.
[0078] In particular, the step of connecting each measuring slot 8a, 8b to the respective
air loading slot 5a, 5b and the end of the respective article 100 occurs after the
step of connecting the air loading slot 5a, 5b to the end of the article 100.
[0079] Preferably, each step of measuring performed in one measuring slot 8a, 8b is accompanied
by a corresponding step, preferably simultaneous, of venting the pressure in the other
measuring slot 8a, 8b.
[0080] The operation of the measuring method is described briefly below with reference to
the example embodiment of Figures 4A-4D and with particular regard to the advancing
motion of two consecutive articles 100a, 100b.
[0081] In Figure 4A:
- the first article 100a is starting to be loaded with air from the compressed air source
6a through the connecting slot 7a and the loading slot 5a; the respective vent 9a,
on the other hand, is not in operation;
- the second article 100b is being loaded with air from the compressed air source 6b
through the connecting slot 7b and the loading slot 5b and, simultaneously, the step
of measuring the second article 100b through the measuring slot 8b is starting; the
vent 9b starts moving across the measuring slot 8a to relieve the accumulated pressure.
[0082] In Figure 4B:
- the first article 100a is continuing to be loaded with air; the respective vent 9a
is not in operation;
- the second article 100b is ending the step of loading with air and, simultaneously,
the step of measuring is ending; the vent 9b is ending the step of relieving.
[0083] In Figure 4C:
- the first article 100a is continuing to be loaded with air and, simultaneously, the
step of measuring through the measuring slot 8a is starting and the step of the vent
9a relieving pressure through the measuring slot 8b is starting;
- the second article 100b has been measured and is no longer in fluid communication
with the measuring device 4;
- a further second article 100b, upstream of the first article 100a, is starting to
be loaded with air from the compressed air source 6b through the connecting slot 7b
and the loading slot 5b; the respective vent 9b, on the other hand, is not in operation;
[0084] In Figure 4D:
- the first article 100a is ending the step of loading with air and, simultaneously,
the step of measuring; the vent 9a is also ending the step of relieving;
- the further second article 100b, on the other hand, is continuing to be loaded with
air.
[0085] The cycle described with reference to Figures 4A to 4D is repeated cyclically along
the entire feed path P to allow all the articles 100 to be measured. Compared to what
is described above with reference to Figures 4A-4D, the embodiment illustrated in
Figures 5A-5D comprises an additional step of preloading with air according to this
invention.
[0086] In other words, before reaching the loading slots 5a, 5b, the articles 100 undergo
a step of preloading in the respective preloading slots 10a, 10b.
[0087] This invention overcomes the disadvantages of the prior art by providing a unit and
a method for measuring the pressure drop in a smoking article making it possible to
increase the time available for supplying an air flow into the article so as to be
able to measure real pressure drop values of a wide range of articles, in particular
those whose RTD is higher than that of traditional cigarettes. Thanks to the air loading
slots which are longer than those of the prior art and which are managed with alternate
selective logic, it is possible, under otherwise equal conditions, to load the smoking
articles with a larger quantity of air.
[0088] The invention is therefore able to enhance the versatility of machines for making
smoking articles without modifying the overall dimensions of the measuring unit and
without having to modify the speed at which the articles are fed.
1. A unit (1) for measuring the pressure drop in a smoking article (100), comprising:
- a conveyor (2) comprising a plurality of housing seats (3) configured to receive
and transversely feed a plurality of rod-shaped smoking articles (100) along a feed
path (P);
- a fixed measuring device (4) disposed on the feed path (P) and configured to measure
a value of pressure drop in each article (100), wherein the measuring device (4) comprises
at least one air loading slot (5a, 5b) connected or connectable to a compressed air
source (6a, 6b);
- connecting means (7) disposed on the conveyor (2) and configured to connect the
at least one air loading slot (5a, 5b) sequentially to one of the housing seats (3)
in order to feed an air flow to the articles (100); characterized in that the measuring device (4) comprises at least two air loading slots (5a, 5b) connected
or connectable to respective, distinct compressed air sources (6a, 6b) and in that the connecting means (7) are configured to alternately connect consecutive housing
seats (3a, 3b) to different air loading slots (5a, 5b).
2. The unit (1) according to claim 1, wherein the at least two air loading slots (5a,
5b) extend along respective directions of extension parallel to the feed path (P)
of the articles (100) and are juxtaposed with each other along a direction perpendicular
to the feed path (P), and wherein the connecting means (7) comprise, for each housing
seat (3a, 3b), a respective connecting slot (7a, 7b) configured to pneumatically connect
the respective article (100a, 100b) to a respective air loading slot (5a, 5b) and
wherein the connecting slots (7a, 7b) are disposed in at least two alternate sets
in such a way that consecutive housing seats (3a, 3b) correspond to connecting slots
(7a, 7b) of distinct sets configured to be connected to different air loading slots
(5a, 5b).
3. The unit (1) according to claim 2, wherein the connecting slots (7a, 7b) extend between
the respective article (100a, 100b) and the respective air loading slot (5a, 5b) along
respective directions of extension transverse, preferably perpendicular, to the feed
path (P).
4. The unit (1) according to one or more of the preceding claims, wherein the measuring
device (5) comprises, for each air loading slot (5a, 5b), a respective measuring slot
(8a, 8b) which is juxtaposed with the respective air loading slot (5a, 5b) and inside
which there is a pressure sensor configured to measure a value of pressure drop associated
with a respective article (100a, 100b), each measuring slot (8a, 8b) being placed
in fluid communication with the respective air loading slot (5a, 5b) by the connecting
means (7).
5. The unit (1) according to claim 4, wherein the measuring slot (8a, 8b), the respective
air loading slot (5a, 5b) and the respective article (100a, 100b) to be measured are
placed in mutual fluid communication simultaneously by the connecting means (7) for
a certain operating stretch of the feed path (P).
6. The unit (1) according to claim 5, wherein each measuring slot (8a, 8b) at least partly
overlaps the respective air loading slot (5a, 5b) along the feed path (P), and wherein
the measuring slot (8a, 8b) preferably overlaps only an end portion of the respective
air loading slot (5a, 5b) along the feed path (P) so that the pressure is measured
only when the article (100a, 100b) is in communication with that end portion of the
of the air loading slot (5a, 5b).
7. The unit (1) according to any one of claims 4 to 6, wherein the measuring slots (8a,
8b) extend along respective directions of extension parallel to the feed path (P)
of the articles (100a, 100b).
8. The unit (1) according to claim 7, when dependent on claim 3, wherein the air loading
slots (5a, 5b) are interposed between the measuring slots (8a, 8b) relative to a direction
transverse to the feed path (P).
9. The unit (1) according to one or more of claims 4-6, wherein the conveyor (2) comprises,
for each housing seat (3a, 3b), a respective vent (9a, 9b) configured to intercept
a respective measuring slot (8a, 8b) and to relieve the pressure in the measuring
slot (8a, 8b), and wherein the vents (9a, 9b) are disposed on the conveyor (3) in
at least two alternate sets in such a way that consecutive vents (9a, 9b) intercept
different measuring slots (8a, 8b).
10. The unit (1) according to claim 9, wherein, for each housing seat (3a, 3b), the respective
vent (9a, 9b) is disposed on the side opposite to the respective connecting slot (7a,
7b) so that when the connecting slot (7a, 7b) associated with the housing seat (3a,
3b) is in communication with a respective measuring slot (8a, 8b), the respective
vent (9a, 9b) is in communication with the other measuring slot (8a, 8b).
11. The unit (1) according to one or more of the preceding claims, wherein the conveyor
(2) is a drum which rotates about an axis of rotation (X) and has, for each housing
seat (3a, 3b), at least one supporting element (3') for an end portion of an article
(100a, 100b) housed in the housing seat (3a, 3b), the supporting element (3') being
associated with the connecting means (7); and wherein the feed path (P) defines a
circular path, the at least two air loading slots (5a, 5b) extending along arcuate
directions of extension.
12. The unit (1) according to one or more of the preceding claims, wherein the measuring
device (4) comprises, for each air loading slot (5a, 5b), a respective air pre-loading
slot (10a, 10b) disposed upstream of the air loading slot (5a, 5b) relative to the
feed path (P) and connected or connectable to a respective compressed air source (6c,
6d) distinct from the compressed air source (6a, 6b) of the respective air loading
slot (5a, 5b) and wherein the connecting means (7) are also configured to alternately
connect consecutive housing seats (3a, 3b) to different air pre-loading slots (10a,
10b).
13. The unit (1) according to claim 11, wherein each air pre-loading slot (10a, 10b) is
aligned with the respective air loading slot (5a, 5b) in such a way that each article
(100a, 100b) is placed in fluid communication, by the connecting means (7), first
with an air pre-loading slot (10a, 10b) and then with the respective air loading slot
(5a, 5b).
14. The unit (1) according to claim 12 or 13, wherein each air pre-loading slot (10a,
10b) is greater than or equal to the respective air loading slot (5a, 5b) in length.
15. A method for measuring the pressure drop in a smoking article (100), comprising the
following steps:
- transversely feeding a plurality of rod-shaped smoking articles (100) along a feed
path (P) through a fixed measuring device (4), the measuring device (4) comprising
at least one air loading slot (5a, 5b) connected or connectable to a compressed air
source (6a, 6b);
- placing one end of each smoking article (100) in fluid communication with the at
least one air loading slot (5a, 5b);
- measuring the value of pressure drop of each article connected to the air loading
slot (5a, 5b);
characterized in that the measuring device (4) comprises two air loading slots (5a, 5b) connected or connectable
to distinct compressed air sources (6a, 6b) and
in that the step of measuring the value of pressure drop of each article (100) is performed
by alternately connecting the ends of consecutive articles (100a, 100b) to different
air loading slots (5a, 5b).
16. The method according to claim 15, wherein the step of measuring the value of pressure
drop of an article (100a, 100b), performed while the article (100a, 100b) is connected
to an air loading slot (5a, 5b), is performed simultaneously with a step of placing
one end of the next consecutive article (100a, 100b) in fluid communication with a
different air loading slot (5a, 5b).
17. The method according to claim 15 or 16, wherein the step of measuring a first article
(100a) starts simultaneously with the starting of the step of placing one end of a
second article (100b), following the first article (100a), in fluid communication
with a respective air loading slot (5a, 5b).
18. The method according to claim 17, wherein the air loading slots (5a, 5b) have the
same extension, be it linear or angular, along the feed path (P) and wherein the step
of measuring the pressure drop of the first article (100) starts while the end of
the first article (100a) is disposed at an end portion of the respective air loading
slot (5a), further downstream, so that the step of measuring the first article (100a)
starts substantially simultaneously with the starting of the step of placing one end
of a second article (100b) in fluid communication with the respective air loading
slot (5b).
19. The method according to one or more of claims 15 to 18, wherein the measuring device
(4) comprises, for each air loading slot (5a, 5b), a respective measuring slot (8a,
8b) inside which there is a pressure sensor, and wherein the step of measuring is
performed by connecting together the end of the article (100a, 100b) measured, the
air loading slot (5a, 5b) and the measuring slot (8a, 8b) by means of a single connecting
slot (7a, 7b) which is movable as one with the article (100a, 100b), there being two
distinct sets of connecting slots (7a, 7b) disposed in alternate succession at consecutive
articles (100, 100b) so that consecutive articles (100a, 100b) are connected to different
air loading slots (5a, 5b) and different measuring slots (8a, 8b).
20. The method according to claim 19, wherein the step of connecting each measuring slot
(8a, 8b) to the respective air loading slot (5a, 5b) and the end of the respective
article (100a, 100b) occurs after the step of connecting air loading slot (5a, 5b)
to the end of the article (100a, 100b).
21. The method according to claim 19 or 20, wherein each step of measuring performed in
one measuring slot (8a, 8b) is accompanied by a corresponding step, preferably simultaneous,
of venting the pressure in the other measuring slot (8a, 8b).
22. A unit (1) for measuring the pressure drop in a smoking article (100), comprising:
- a conveyor (2) comprising a plurality of housing seats (3) configured to receive
and transversely feed a plurality of rod-shaped smoking articles (100) along a feed
path (P);
- a fixed measuring device (4) disposed on the feed path (P) and configured to measure
a value of pressure drop in each article (100), wherein the measuring device (4) comprises
at least one air loading slot (5a, 5b) connected or connectable to a compressed air
source (6a, 6b);
- connecting means (7) disposed on the conveyor (2) and configured to connect the
at least one air loading slot (5a, 5b) sequentially to one of the housing seats (3)
in order to feed an air flow to the articles (100); characterized in that the measuring device (4) comprises, for each at least one air loading slot (5a, 5b),
a respective air pre-loading slot (10a, 10b) disposed upstream of the air loading
slot (5a, 5b) relative to the feed path (P) and connected or connectable to a respective
compressed air source (6c, 6d) distinct from the compressed air source (6a, 6b) of
the respective air loading slot (5a, 5b) and wherein the connecting means (7) are
also configured to connect the at least one pre-loading slot (10a, 10b) to one of
the housing seats (3).