Method for adjusting the diameter of an elongated rod

Abstract

The invention relates to a method for adjusting the diameter of an elongated rod, said method comprising: providing an elongated rod having a preliminary diameter; selecting a desired final diameter of the elongated rod; providing a diameter adjusting device including a first tubular element having an inlet and an outlet and a channel connecting the inlet and the outlet; adjusting the diameter of the outlet as a function of the desired final diameter of the elongated rod, wherein the diameter of the inlet is bigger than the diameter of the outlet when adjusted; and inserting the elongated rod in the diameter adjusting device from the inlet and outputting it from the outlet so that said elongated rod is compressed to the desired final diameter when outputted from the outlet of the first tubular element.

Claims

1. A method for manufacturing an aerosol forming device, including: providing an elongated rod having a preliminary diameter; selecting a desired final diameter of the elongated rod; providing a diameter adjusting device including a first tubular element having an inlet and an outlet and a channel connecting the inlet and the outlet, wherein said first tubular element includes an elastic portion, the elastic portion including the outlet; adjusting the diameter of the outlet as a function of the desired final diameter of the elongated rod, wherein the diameter of the inlet is bigger than the diameter of the outlet when adjusted, wherein adjusting the diameter of the outlet includes compressing or decompressing the elastic portion; inserting the elongated rod in the diameter adjusting device from the inlet and outputting it from the outlet so that said elongated rod is compressed to the desired final diameter when outputted from the outlet of the first tubular element; providing the elastic portion with slits cutting the elastic portion substantially along a longitudinal axis of the first tubular element; and compressing or decompressing the elastic portion by reducing or enlarging the slits spacing.

2. The method according to claim 1, including: measuring the diameter of the elongated rod at the outlet of the first tubular element; and adjusting the diameter of the outlet of the first tubular element on the basis of the diameter measurement.

3. The method according to claim 1, wherein the elastic portion includes an outer surface which is funnel-shaped or an inner surface which is funnel-shaped, or both an inner and an outer surfaces which are funnel-shaped, when the adjusting the diameter of the outlet takes place.

4. The method according to claim 1, comprising: covering said slits by inserting a tubular cover onto the elastic portion to cover an inner surface of the elastic portion where the slits are present.

5. The method according to claim 1, comprising: providing the diameter adjusting device with a second tubular element; partially inserting the first tubular element into the second tubular element; and adjusting the diameter of the outlet of the first tubular element by inserting the first tubular element for a longer or shorter portion into the second tubular element.

6. The method according to claim 5, comprising: providing the first tubular element with a tapered external surface portion including the outlet, the tapered external surface portion having the widest dimension of its external surface at the outlet of the first tubular element; providing the second tubular element with a tapered internal surface portion, the tapered internal surface having a mating shape with the external surface of the tapered external surface portion of the first tubular element; and inserting the first tubular element inside the second tubular element so that the tapered external surface portion of the first tubular element is compressed due to the tapered internal surface portion of the second tubular element.

7. The method according to claim 5, wherein the inserting the first tubular element into the second tubular element comprises: providing the first tubular element with a threated portion at the inlet; providing a collar coupled to the threated portion; and screwing or unscrewing the collar to push said first tubular element inward or outward, respectively, the second tubular element.

8. The method according to claim 5, wherein the inserting the first tubular element into the second tubular element comprises: providing a magnetic actuator or a hydraulic system to insert the first tubular element for a longer or shorter portion into the second tubular element.

9. The method according to claim 1, comprising: providing the elastic portion with an inflatable element; and compressing or decompressing the elastic portion by inflating or deflating the inflatable element.

10. The method according to claim 1, comprising: creating a seat for a conveyor belt in an inner surface of the first tubular element; positioning the conveyor belt through the seat in the first tubular element; placing the elongated rod into the conveyor belt; and moving the conveyor belt in a direction from the inlet to the outlet of the first tubular element so that the elongated rod is compressed while exiting the first tubular element.

11. The method according to claim 1, comprising: providing a conveyor belt transporting the elongated rod up to the inlet of the first tubular element; and forcing the elongated rod into said inlet by a force applied by incoming following portions of the elongated rod still present onto the conveyor belt.

12. The method according to claim 1, comprising: displaying information relative to the outlet diameter of the first tubular element.

13. The method according to claim 1, comprising: sensing a compression strength needed to compress the elongated rod to the final diameter.

14. The method according to claim 13, comprising: modifying the final diameter of said outlet of the first tubular element as a function of said compression strength.

15. The method according to claim 1, wherein the first tubular element is radially symmetric.

16. The method according to claim 1, comprising: including the elongated rod having the adjusted diameter in an aerosol forming device.

Description

(1) The invention will be further described, by way of example only, with reference to the accompanying drawings in which:

(2) FIG. 1 shows a lateral perspective view of an element of a first embodiment of a diameter adjusting device used in the method of the invention;

(3) FIG. 2 shows a lateral view in section of the first embodiment of the diameter adjusting device including the element of FIG. 1;

(4) FIG. 3 shows a phase of the method of the invention using the first embodiment of the diameter adjusting device of FIG. 1;

(5) FIG. 4 shows a lateral view in section of a second embodiment of a diameter adjusting device used in the method of the invention;

(6) FIG. 4a shows an enlarged perspective view of an element of the second embodiment of the diameter adjusting device of FIG. 4;

(7) FIG. 5 shows a lateral view in section of a third embodiment of a diameter adjusting device used in the method of the invention;

(8) FIG. 6 shows a front view of a fourth embodiment of a diameter adjusting device used in the method of the invention with some element removed;

(9) FIG. 7 shows a front view of the fourth embodiment of the diameter adjusting device of FIG. 6 with the elements which were removed in FIG. 6 added; and

(10) FIG. 8 schematically shows a perspective view of an elongated rod, subject to the method of the invention.

(11) The method of the invention operates on an elongated rod 50 such as the one schematically depicted in FIG. 8. The elongate rod 50 has a preliminary diameter before the application of the method of the invention and reaches a final diameter afterwards. The final diameter is smaller than the preliminary diameter. The elongated rod may be wrapped in paper 31 (shown only in FIG. 7), called wrapping paper.

(12) The method of the invention modifies the preliminary diameter of the elongated rod 50 into the final diameter by means of a diameter adjusting device.

(13) A first embodiment of a diameter adjusting device 1 used in the method according to the invention is represented in FIGS. 1-3.

(14) In all embodiments, element which are substantially identical have been identified with the same reference numeral.

(15) The diameter adjusting device 1 includes a first tubular element 2 defining an inner channel 3 which connects an inlet 4 and an outlet 5 of the first tubular element 2. The first tubular element 2 defines a longitudinal axis X passing through the channel 3 and through the inlet and the outlet. Preferably, a cross section of the channel 3 along a plane perpendicular to the longitudinal axis X defines a shape which is radially symmetric. In the depicted embodiment, the defined shape is a circumference. Preferably, all cross sections of the channel 3 along planes perpendicular to the X axis define each a radially symmetric shape and more preferably the shapes are circumferences. Also the inlet 4 and the outlet 5 of the channel 3 are circular, that is, they are circumferences. Therefore, the inlet 4 and the outlet 5 define an inlet diameter and an outlet diameter, respectively. The outlet diameter is preferably equal to or smaller than the inlet diameter.

(16) The first tubular element 2, visible in detail in FIGS. 1 and 2, further defines an internal surface 6, which is the surface of the channel 3, and an external surface 7. Preferably, the internal surface 6, when the first tubular element 2 is in an uncompressed state, is substantially cylindrical, that is, all cross sections along a plane perpendicular to the longitudinal axis X of the channel 3 define circumferences having all the same diameter. In an uncompressed state (shown in FIG. 1), therefore, the diameter of the inlet 4 is substantially identical to the diameter of the outlet 5.

(17) Further, the external surface 7 comprises a first portion 8 having a first length along the X axis and preferably substantially cylindrical, that is, the first portion 8 includes a cylindrical surface having a constant diameter in cross section along planes perpendicular to the longitudinal axis X for the first length. The external surface also includes a second portion 9 which is tapered for a second length, that is, cross sections of this tapered external surface along planes perpendicular to the X axis and taken at different position along the X axis define shapes having different diameters. The first and second portions 8, 9 are geometrically consecutive one to the other and one extends from the other along the longitudinal axis X. Preferably, the second tapered portion 9 has a cone-like shape, which means that all cross sections of the second portion 9 along plane perpendicular to the X axis define circumferences, which may have different diameters depending on the position along the X axis where the sectioning plane is positioned. The largest diameter defined by the tapered second portion 9 of the external surface 7 in a cross section along a plane perpendicular to the longitudinal axis X is at the outlet 5 of the channel 3 and the diameters of the cross sections of the second tapered portion 9 decrease moving the sectioning plane towards the inlet 4.

(18) The diameter of the outlet 5 can, according to the invention, be adjusted in real time.

(19) The first tubular element 2 further includes an elastic portion 11. Preferably, the elastic portion 11 comprises the second tapered surface 9. In this first embodiment of FIGS. 1-3, the elastic portion 11 includes one or more kerf cuts 12 or slits along its length. The cuts 12 depart from the outlet 5, extend towards the inlet 4, and are preferably substantially parallel to the X axis. The cuts 12 divides the elastic portion 11 in “jaws” 13 and thus also divides the outlet 5 in separated arcs of circumference, one for each jaw 13. Preferably, the cuts 12 are radially symmetric so that the jaws 13 are also radially symmetric.

(20) The kerf cuts 12 allow the elastic portion 11 to contract when pressing on the external surface 9 of the first tubular element 2 at the elastic portion 11, making the jaws cylindrical opening diameter, which is the diameter of outlet 5, becoming smaller than the overall inside diameter of the channel 3, and in particular smaller than the diameter of the inlet 4. Indeed, when compressed, the spacing between the various jaws 13 decreases and also the spacing between the different arcs of circumference forming the outlet 5 also decreases, reducing its diameter. When jaws 13 are compressed, the inner surface 6 of channel 3 includes also a tapered portion, where the jaws 13 are located.

(21) Reciprocally, the jaws cylindrical opening diameter, that is the outlet diameter, expands when releasing such pressure, and—as already mentioned—in the uncompressed state the diameter of the outlet 5 can reach the inlet diameter. In this state, the channel 3 has an overall diameter which is equal along its whole length. In this way, the diameter of the outlet 5 can be varied and regulated, operating on jaws 13.

(22) The diameter adjusting device 1 further includes a second tubular element 14. The second tubular element 14 also defines an inner channel 15 connecting an inlet 19 and an outlet 20, and an inner surface 16. The inner surface 16 of the channel 15 of the second tubular element 14 is preferably funnel shaped and more preferably includes two geometrically consecutive portions, a first portion 17 having a constant diameter for a given length along the longitudinal axis X and a second portion 18 which is tapered. Advantageously, the inner surface 16 of channel 15 is radially symmetric. Preferably, the second portion 18 has a taper which mates in shape the second tapered portion 9 of the first tubular element 2, for example they have the same slope. In this configuration, the outlet 20 of the second tubular element 14 has a larger diameter than the inlet 19 of the second tubular element. The first tubular element 2 is inserted into the second tubular element 14 along the X axis, introducing the first tubular element in the outlet 20 of the second tubular element. When the first tubular element 2 is inserted in the second tubular element 14, channel 3 and channel 15 are substantially coaxial both having as longitudinal axis the X axis. The first tubular element 2 is inserted with its inlet 4 forward. The insertion terminates when the tapered portion 9 of the external surface 7 of the first tubular element 2 abuts onto the tapered portion 18 of the inner surface 16 of the second tubular element 14. A further insertion of the first tubular element 2 into the second tubular element 14 results in the exertion of a force on the elastic portion 11 of the first tubular element 2, compressing the jaws 13, decreasing the diameter of the outlet 5 of the first tubular element 2.

(23) Preferably, the first tubular element 2 includes threads 21 formed at its inlet 4. Preferably, the threads are formed in a portion of the external surface 7 of the first tubular element 2 which protrudes from the second tubular element 14 and therefore is accessible from the outside. The diameter adjusting device 1 further includes regulating means for the regulation of the diameter of the outlet 5. The regulating means include, in the embodiment of FIGS. 1-3, an outer collar 22 that can be screwed on threads 21 creating a force 23, depicted with an arrow in FIG. 2, drawing the first tubular element 2 further into the second tubular element 14.

(24) Accordingly, when the first tubular element 2 is drawn into the second tubular element 14 by means of the screwing of the collar 22 on the threads 21, the second tapered portion 18 of the second tubular element 14 presses on the jaws 13 of the second tapered portion 9 of the first tubular element 2, which in turn decreases the inner diameter of the elastic portion 11 of the channel 3, including the outlet 5. This reduction in diameter is obtained applying a radial force on the jaws 13 of the elastic portion 11. If the elongated rod 50 is present inside the first tubular element 2, this radial force is in turn applied onto the elongated rod 50. Unscrewing the collar 22 from the threads 21 reduces the compression force and in turn increases the diameter of the outlet 5 due to a reduced compression on the jaws 13 of the elastic portion 11.

(25) According to a different embodiment of the invention, not depicted, the regulating means instead of threads 21 and collar 22 include a hydraulic system that can tight or loose the jaws 13 of the elastic portion 11.

(26) According to an even further different embodiment of the invention, also not depicted in the appended drawings, the regulating means include a magnetic system that can tight or loose the jaws 13 of the elastic portion 11.

(27) Preferably, the diameter adjusting device 1 comprises a sensor 24 apt to measure the amount of compression force exerted by the jaws 13 onto the elongated rod 50, when the latter is inserted in the first tubular element 2, and to emit signals function of the measured compression value. Moreover, diameter adjusting device 1 may include a control unit 25 apt to receive the signals emitted from the sensor 24 in order to optionally command the regulating means to change the dimension of the diameter of the outlet 5 depending on the value of the signals sent by sensor 24.

(28) Advantageously, the diameter adjusting device 1 may also comprise a diameter measuring device, not shown in the drawing, located downstream of the outlet 5, adapted to measure the final diameter of the elongated rod exiting the first tubular element 2. The diameter measuring device is preferably connected to the control unit 25 adapted to receive the signals emitted from the diameter measuring device in order to optionally command the regulating means to change the dimension of the diameter of the outlet 5 depending on the value of the signals sent by the diameter measuring device.

(29) The method of the invention will be now described with reference to FIG. 3. The tubular rod 50 having a preliminary diameter and obtained with any method known in the field is inserted inside the diameter adjusting element 1 via the inlet 4. The rod 50 is advanced into the first tubular element 2 in the direction indicated by the arrow 26. Meanwhile, a specific diameter of the outlet 5 has been selected and set by means of the regulating means, in this case collar 22 and threats 21, as a function of the desired final diameter of the elongated rod 50. The diameter of the outlet 5 which has been selected imposes a specific configuration on the jaws 13 which compress the rod 50 while it exits the first tubular element 2. The rod 50 coming out of the first tubular element has thus a final diameter which is function of the diameter of the outlet 5.

(30) In the embodiment where the diameter adjusting device has a radial symmetry, the diameter adjusting device 1 advantageously provides an identical centered pressing force onto the elongated rod 50 all around its outer circumference, due to the fact that the elastic portion 11 is radially symmetric and the element compressing the elastic portion is also radially symmetric, and therefore it produces a cylindrical elongated rod 50 with selected hardness all around its outer circumference. Further, being the inner surface 6 in contact to the rod 50 substantially continuous or with minimal cuts having a very small dimension, no marks are produced on the surface of the rod 50.

(31) Preferably, the final diameter of the elongated rod 50 outputted from the diameter adjusting device 1 may be measured by the diameter measuring device. The diameter of the outlet 5 is thus varied accordingly depending on the measured diameter of the outputted rod. Preferably, a comparison is made between the measured final diameter of the rod and the desired final diameter. Depending on the value of the difference, the outlet diameter may be changed, for example by means of a command of the control unit 25 which elaborates the signals coming from the diameter measuring device. Further, preferably the force necessary to compress the elongated rod 50 to its final diameter is measured by means of sensor 24 and the outlet diameter possibly varied accordingly, depending on the value of the measurement. Signals function of the compression force are for example sent by sensor 24 to control unit 25 which elaborates the signal and possibly changes the diameter of the outlet 5. For example, if the compression force is above a first force threshold, the resulting elongated rod may have a too high firmness, therefore it is preferable that the diameter outlet is increased, operating by a suitable signal the regulating means. In case a weak force, that is a force below a second force threshold, is applied to the elongated rod, than the firmness of the resulting elongated rod may result too low. In this case, therefore, a decrease in the width of the diameter is preferred and a command to the regulating means to decrease the size of the outlet is preferably sent. Alternatively, a higher resistance to compression of the material forming the rod 50 can be balanced by a slightly larger diameter of the outlet 5 so that the overall elongated rod hardness or firmness results unchanged from an optimal range of value. Reciprocally, a lower resistance to compression of the material forming the rod 50 can be balanced by a slightly tighter diameter of the outlet 5 so that the overall elongated rod hardness or firmness remains unchanged from an optimal range of values.

(32) According to a second embodiment depicted in FIGS. 4 and 4a, the diameter adjusting device 10 includes a tubular hollow cover 27 to cover cuts 12 of the elastic portion 11, to avoid the cuts to mark the elongated rod 50, and more preferably to avoid marks on the wrapping paper which may wrap the elongated rod 50. The tubular hollow cover 27 may be over molded, glued or stuck to the inner surface 6 of the channel 3, to offer a continuous surface to the elongated rod 50. Preferably, the tubular hollow cover 27 has a shape of a hollow elastic cone. An inner surface coating with PTFE or silicon can be applied to reduce friction between the inner surface 6 and the elongated rod 50.

(33) The functioning of this second embodiment is analog to that of the first embodiment.

(34) In a third embodiment of the diameter adjusting device 100 depicted in FIG. 5, the elastic portion 11 comprises an internal inflatable part 28, which can be inflated to adjust the internal diameter of the elastic portion 11. The inflatable part is located at the elastic portion, including the outlet 5, and can change the size of the inner surface of the channel 3 in cross section. In this way the diameter of the outlet 5 can be adjusted, changing the quantity of fluid inside the inflatable part 28.

(35) The functioning of the third embodiment of the diameter adjusting device 100, besides the inflation or deflation of the elastic portion, is analog to the functioning of the diameter adjusting device 1 according to the first embodiment.

(36) According to a fourth embodiment of the invention, not depicted in the drawings, the elongated rod 50 having the preliminary diameter is brought to the diameter adjusting device 1, 10, 100 at its inlet 4, by means of a first conveyor belt. In the fourth embodiment of the invention, the first conveyor belt ends at the inlet, that is, the conveyor belt, preferably a high speed conveyor belt, does not run into the first tubular element 2, but it stops before entering in the inlet 4. The elongated rod 50 is pushed into the first tubular element 2 by the frictions forces of the incoming other parts of the rod which are still on the outside first conveyor belt. At the outlet 5 of the first tubular element 2, after compression, a second conveyor belt is preferably present, to transport the compressed elongated rod 50 having its final diameter away from the diameter adjusting device 1, 10, 100. Preferably, also the second conveyor belt is a high speed conveyor belt. The tubular rod 50 having the final diameter is pushed onto the second conveyor belt at the outlet 5 of the first tubular element 2, and the second conveyor belt drags the rod 50 out of the first tubular element 2, using the friction forces of the elongated rod portions which have already exited the first tubular element, as well as the paper resistance to tearing in case of a wrapped elongated rod 50.

(37) In an alternative fifth embodiment, depicted in FIGS. 6 and 7, the diameter adjusting device 200 includes a single conveyor belt 29, preferably a high speed conveyor belt, which runs into and through the first tubular element 2. Preferably, the conveyor belt 29 is U shaped at least for its portion located inside the first tubular element 2, so as to abut onto the inner surface 6 of the channel 3, preferably without forming gaps.

(38) In this embodiment, the channel 3 is not radially symmetric as in the previous embodiments. A portion of the inner surface 6 includes a seat 30 apt to house the conveyor belt 29. Therefore, a cross section of the channel 3 on a plane perpendicular to the X axis defines a first arc of circumference in correspondence of seat 30 having a first radius and a second arc of circumference having a second radius, where the seat is not present. The first radius is longer than the second radius. The size of the conveyor belt 29, in cross section, that is, the conveyor belt thickness, is such that when the conveyor belt is inserted in seat 30, the thickness of the conveyor belt matches the difference between the first and second radius, so that, once the conveyor belt 29 is inside the seat 30, the global inner surface formed by inner surface 6 and top surface 33 of the conveyor belt 29 into which is in contact with the elongated rod 50 is a cylinder.

(39) The seat 30 and the difference between the first and second radius defined in the seat 30 region and in the region seat-free of channel 3 are visible in FIG. 6.

(40) In the second front view of FIG. 7, the conveyor belt 29 inside seat 30 is represented. In this view, also the elongated rod 50 is shown, wrapped in paper 31, inserted in the first tubular element 2 on the conveyor belt 29.

(41) In all mentioned embodiments of the diameter adjusting device 1, 10, 100, 200, the device, for example the regulating means, may be adapted to display information indicating the outlet diameter of the first tubular element 2.

(42) Further, strength sensor 24 giving information about the compression strength needed to change the diameter of the elongated rod 50 into the final diameter and a diameter measuring device to measure the final diameter of the elongated rod exiting the outlet of the first tubular element may be present in all embodiments of the diameter adjusting device 1, 10, 100, 200. Control unit 25 apt to emit signals as feedback to the signals received by sensor 24 and diameter adjusting device may be present as well.

(43) The so formed elongated rod 50 having its final diameter may be further processed in order to obtain an aerosol-forming article (not depicted in the appended drawings).