EP3756843A1

EP3756843A1 - Punch tool and method of working a punch tool

Info

Publication number: EP3756843A1
Application number: EP19183447.2A
Authority: EP
Inventors: Rui Nuno BATISTA; Oscar Slurink
Original assignee: Philip Morris Products SA
Current assignee: Philip Morris Products SA
Priority date: 2019-06-28
Filing date: 2019-06-28
Publication date: 2020-12-30

Abstract

A punch tool for producing an element by punching from a medium comprising a punch shaft and a perforation member.

Description

This invention relates generally to a punch tool and a method of working a punch tool. More specifically, although not exclusively, this invention relates to a punch tool for producing a disc of High-Retention-Material (for example a High-fluid-retention-material) from a medium.
A number of devices for generating an aerosol have been proposed in the art. For example, devices for generating aerosols which heat rather than combust an aerosol-forming substrate have been proposed. Heated smoking devices in which tobacco is heated rather than combusted, are one type of such device. An aim of such smoking devices is to reduce the generation of unwanted and harmful smoke constituents as produced by the combustion and pyrolytic degradation of tobacco in conventional cigarettes. These heated smoking devices are commonly known as 'heat not burn' devices.
Heated smoking devices of the above-described type commonly comprise a heating chamber, provided with, or defined by, heating surfaces, into which an article for forming an aerosol is inserted, prior to use. The article typically contains an aerosol-forming substrate which is heated by a heating element of the device to generate an aerosol. The aerosol is entrained in air drawn through the aerosol-generating article to the user. When the aerosol-forming substrate contained in an article has been exhausted the article can be replaced. The heated smoking device thereby constitutes a reusable device whilst the article comprises a 'consumable' product.
Within the heated smoking device, a transport material (or capillary material) soaked in the aerosol-forming substrate is typically used to supply aerosol-forming substrate to the heating element. During manufacture, the transport material is placed in fluid communication with the heating element. The transport material may be located within a housing or heater mount, which can comprise a part of a cartridge portion, and typically comprises a porous or fluid permeable material having a network of small pores or micro-channels through which the liquid aerosol-forming substrate is transported or permeates.
The dimensions of the transport material are generally slightly larger than the internal dimensions of the heater mount in order to provide a tight fit between the heater mount and the transport material, which helps to reduce the likelihood of leaks around the edges of the transport material. As a result, during insertion, the transport material is compressed orthogonal to the thickness direction of the transport material and towards the centre of the transport material, which may cause a closure or at least a decrease in the size of a proportion of the pores or micro-channels of the transport material. Consequently, transport of liquid aerosol-forming substrate through the transport material may be interrupted or reduced, which may result in insufficient liquid aerosol-forming substrate being present at the fluid permeable heating element. It is generally desirable to ensure that a minimum amount of liquid aerosol-forming substrate is present in the transport material to avoid a "dry-heating" situation, in other words a situation in which the fluid permeable heating element is heated with insufficient liquid aerosol-forming substrate being present. This situation is also known as a "dry puff" and can result in overheating and, potentially, thermal decomposition of the liquid aerosol-forming substrate, which can produce undesirable byproducts such as formaldehyde.
To avoid a "dry-heating situation" in some examples the transport material is provided with at least one hole which defines a formed fluid channel for liquid aerosol-forming substrate. The hole remains open even when the transport material is compressed when inserted into the housing such that liquid aerosol-forming substrate can freely enter the hole. The hole extends into the transport material to a depth corresponding to at least a part of the thickness of the material such that the thickness of the transport material, and hence the resistance to fluid flow, is reduced in the region of the hole. This assists liquid aerosol-forming substrate to reach the fluid permeable heating element and reduces the likelihood of a dry puff and formaldehyde production.
Figure 1a illustrates an example of a transport material including a hole. The transport material of the consumable is a small disc of "High-Retention-Material" (HRM). The HRM disc 100 stores liquid aerosol-forming substrate for the aerosol generation within the aerosol generating device. For example, the liquid aerosol-forming substrate stored in the HRM disc is nicotine. An example of a disc 100 of HRM is shown in Figure 1. The HRM-discs typically have a specified outer diameter 102 and a central cavity with a diameter 104, that extends at least partially through the thickness 106 of the disc, in order to conform to the required specifications for production. Typically, the disc is produced by punching the required shape from a medium, and by perforating the central cavity (without removal of material).
The HRM is typically a fibrous or spongy medium, that may be stiffened to have a memory effect. This creates difficulties in producing the disc accurately in large quantities. Specifically, it is difficult to punch and perforate accurately with this small diameter of D₁.
Figure 1b illustrates a cross-section of an example of a transport material 124 including a hole. In this example, the transport material 124 is formed of elongate fibres (as shown in the close-up view), which are aligned substantially parallel to the first 124a and second 124b surfaces of the transport material 124. Liquid is conveyed through the transport material 124 in the small spaces or micro-channels between the elongate fibres 124c by capillary action. Although some liquid is transported through the thickness of the transport material 124, the predominant direction of liquid transport is along the fibres, in other words substantially parallel to the first 124a and second 124b surfaces of the transport material 124. This arrangement prevents too much liquid being transported to the fluid permeable heating element, which may result in leaks and drops of liquid aerosol-forming substrate being deposited in the airflow passage. Furthermore, it helps to spread out the liquid aerosol-forming substrate over the area of the fluid permeable heating element to assist in uniform wetting of the heating element. However, due to the compression of the transport material 124 described above the micro-channels at the centre of the transport material 124 can be constricted which inhibits the transport of liquid aerosol-generating substrate through the transport material 124, (in other words from the retention material to the fluid permeable heating element). The hole 126 seeks to overcome this problem by providing a formed fluid channel in the central region of the transport material to allow sufficient liquid aerosol-generating substrate to reach the fluid permeable heating element in order to avoid a dry puff situation. The hole 126 extends in a direction substantially perpendicular to the average direction of the elongate fibres 124c.
Figure 20 illustrates a cross-section of a cartridge 100 of an aerosol generating system, the cartridge including a transport material. Cartridge 1000 comprises an external housing 1050 having a mouthpiece with a mouthpiece opening 1100, and a connection end 1150 opposite the mouthpiece. Within the housing 1050 is a liquid storage compartment holding a liquid aerosol-forming substrate 1310. The liquid storage compartment has a first portion 1300 and a second portion 1350 and liquid is contained in the liquid storage compartment by three further components, an upper storage compartment housing 1370, a heater mount 1340 and an end cap 1380. A heater assembly 1200 comprising a fluid permeable heating element 1220 and a transport material 1240 is held in the heater mount 1340. A retention material 1360 is provided in the second portion 1350 of the liquid storage compartment and abuts the transport material 1240 of the heater assembly 1200. The retention material 1360 is arranged to transport liquid to the transport material 1240 of the heater assembly 1200. The first portion 1300 of the liquid storage compartment is larger than the second portion 1350 of the storage compartment and occupies a space between the heater assembly 1200 and the mouthpiece opening 1100 of the cartridge 1000. Liquid in the first portion 1300 of the storage compartment can travel to the second portion 1350 of the liquid storage compartment through liquid channels 1330 on either side of the heater assembly 1200. Two channels are provided in this example to provide a symmetric structure, although only one channel is necessary. The channels are enclosed liquid flow paths defined between the upper storage compartment housing 1370 and the heater mount 1340.
WO 03/008159 A1 discloses a method of producing elements, such as annular elements, by way of a punching.
US 4836070 discloses a method and apparatus for producing fibrous web pieces by die cutting the pieces from a continuous web.
US 2016/0079585 discloses a method and apparatus for manufacturing terminals for automotive batteries.
Accordingly, a first aspect of the invention provides a punch tool for producing an element by punching from a medium, comprising:

a punch shaft having a punching end; and
a perforation member having a perforation end, the perforation member being mounted within the punch shaft,
wherein the perforation end of the perforation member protrudes from the punching end of the punch shaft;
wherein the punch tool is configured such that during a punching operation, the perforation end of the perforation member perforates the medium, prior to the punching end of the punch shaft punching an element from the medium.

Such a tool allows production (perforation and punching) of a disc with a single motion of the tool. This allows quick and efficient manufacture of the element with less risk of problems.
Aptly, the punch tool further comprises a counterpart, wherein during the punching operation, a mating portion of the counterpart is located adjacent to an opposing side of the medium relative to the punch tool. The counterpart aids punching of the element, in that a clean cut of the element may be made from the medium.
Aptly, the counterpart has an aperture configured to receive the perforation end of the perforation member. Having an aperture configured to receive the perforation end of the perforation member aids the punching action, helping give a clean cut from the medium. That is, the element can be fully perforated by the perforation end of the perforation member while the medium is supported by the counterpart.
Aptly, the mating portion of the counterpart substantially corresponds in shape to the punching end of the punch shaft. This again aids in a clean cut of the element from the medium. That is, the medium is supported by the counterpart in the region from which the element is to be cut.
Aptly, the mating portion of the counterpart is the same size or smaller in cross-section than the punching end of the punch shaft. In this manner, the punching end of the punch shaft can cooperate with the counterpart during a punching operation. In other words, the punch shaft can 'punch around' the counterpart to ensure a clean cut/punch.
Aptly, the punch tool further comprises an element carrier, configured to receive the element from the counterpart. This allows the counterpart/punch shaft/perforation member to be stripped from the punched element, leading to an efficient method of production.
Aptly, the element carrier has an aperture configured to allow the counterpart therethrough, such that a portion of the counterpart is within the element carrier.
Aptly, the aperture of the element carrier is smaller than the element. These features allow the element to be produced and then subsequently stripped from the counterpart, following a single motion of the counterpart/punch shaft/perforation member. This helps ensure an efficient method of production.
Aptly, the punch shaft is substantially cylindrical in shape.
Aptly, the punching end of the punching shaft has a protrusion configured to at least partially cut the element from the medium during the punching operation. The protrusion helps the punching end of the punch tool to punch or cut through the medium in a clean manner.
Aptly, the punching end of the punch shaft is circular. This allows the production of a circular disc as an element.
Aptly, the perforation end of the perforation member is conical. The conical, or needle/pin end of the perforation member helps ensure a clean perforation of the medium. In addition, the surface of the conical end can be used to apply a downward force to the element to assist in moving the element (for example, away from the punch shaft).
Aptly, the perforation member is centrally located within the punch shaft. By locating the perforation member centrally within the punch shaft, the resulting element is centrally perforated.
Aptly, the perforation member is slidably mounted within the punch shaft. Aptly, the perforation member is slidable along a longitudinal axis of the punch shaft. By allowing the perforation member to slide within the punch shaft, the perforation member can be used to move the punched element away from the punch shaft.
Aptly, the counterpart has a first, extended, configuration relative to the element carrier and a second, retracted, configuration relative to the element carrier, wherein in the extended configuration, the counterpart extends through the aperture and is positioned within the element carrier, and wherein in the retracted configuration, the counterpart does not extend through the aperture.
Aptly, the perforation member has first and second configurations relative to the punch shaft; wherein in the first configuration, for use during the punching operation, the perforation end of the perforation member protrudes from the punching end of the punch shaft by a first distance; wherein in the second configuration the perforation end of the perforation member protrudes from the punching end of the punch shaft by a second distance, greater than the first distance. Movement of the perforation end of the perforation member away from the punching end of the punch shaft, can be used to direct the punched element away from the punch shaft, for example towards the element carrier. This can facilitate swift production of the element. That is, a single motion of the punch tool can be used to perforate, punch and then re-locate an element.
Aptly, the perforation member is biased to its first configuration. This ensures the perforation member will swiftly return to its first configuration, to begin a further punching operation.
Aptly, the counterpart moves from its extended configuration to its retracted configuration as the perforation member extends from its first configuration to its second configuration. Syncing the movement of the counterpart and the perforation member allows the punched element therebetween to securely and efficiently moved to a different location, for example the element carrier.
Accordingly, a second aspect of the invention provides a system for producing a plurality of elements by punching from a medium, the system comprising:
a plurality of punch tools according to the first aspect of the invention.
Accordingly, a third aspect of the invention provides a method of working a punch tool (or in other words a method of production of an element from a medium), the method comprising the steps of:

providing a medium, from which an element is to be punched;
providing a punch tool, the punch tool comprising
- a punch shaft having a punching end; and
- a perforation member mounted within the punch shaft, wherein a perforation end of the perforation member protrudes from the punching end of the punch shaft;
moving the punch tool into engagement with the medium to perform a punching operation to produce an element, the punching operation comprising:
- perforating the medium with the perforation end of the perforation member,
- and then punching an element from the medium with the punching end of the punch shaft.

Aptly, perforation of the medium creates a hole that extends at least partially through the thickness of the medium.
Aptly, the punch tool further comprises a counterpart comprising a mating portion, wherein the method further comprises the step of

positioning the medium between the punch shaft the mating portion of the counterpart;
wherein during the punching operation, a mating portion of the counterpart engages with an opposing side of the medium with respect to the punch shaft.

Aptly, the method further comprises the step of:
traversing the perforation end of the perforation member into an aperture in the counterpart as the medium is perforated.
Aptly, the method further comprises the step of passing the element to an element carrier as the counterpart is retracted.
Aptly, the perforation end of the perforation member protrudes further from the punching end of the punch shaft as the counterpart moves through the element carrier.
Aptly, the method further comprises the step of moving the medium in step fashion between the punch shaft and the counterpart, across the path of the punch shaft.
Aptly, the method further comprises the step of replacing the element carrier, with the element thereon, with an empty carrier element.
Certain embodiments of the invention provide the advantage that a punch tool is provided that can both perforate and punch an element from a medium. In particular, certain embodiments of the invention provide a punch tool that can more accurately and repeatably produce an element (as described in the preceding description) from a medium, than prior art punch tools.
Certain embodiments of the invention provide the advantage that a method of working a punch tool (or in other words a method of punching an element from a medium) which is highly repeatable and suitable for high volume operation.
Certain embodiments of the invention provide the advantage that a punch tool (and method of working a punch tool) are provided that allows the element to be separated from the punch tool in an efficient manner. This allows subsequent production/utilisation of the element to be carried out without additional manufacturing steps.
As used herein, the term 'punch' is used to describe the definition of an element within a medium using a punching action (that is, through the application of a targeted compressive force to the medium at the intended perimeter of the element). The applied compressive force may act to shear or cut (and optionally also detach) the element from the medium. Alternatively, the applied compressive force may score the perimeter of the intended element (that is, the element is not completely detached from the medium), for subsequent removal from the medium.
As used herein, the term 'punch shaft' is used to describe the component of the tool used to provide the punching action. In the described examples (although not limited thereto), the punch shaft is substantially cylindrical in shape with a punching end. As used herein, the term punching end' is used to describe the end of the punching shaft, which is used to 'punch' the element within the medium. That is, the punching end' of the punching shaft is the end, which is used to apply the targeted compressive force to the intended perimeter of the element.
As used herein, the term 'medium' is used to describe the structure or substance from which an element is produced. The medium may be made from any suitable material, for example the material may be natural or synthetic. The material may be nylon, polyester, polyethylene, polypropylene or rayon, for example. The medium may be provided in any suitable manner, for example the medium may be provided as an endless strip (that is, the strip being conveyed beneath a punch tool following a punching operation), a sheet or the like.
As used herein, the term 'perforate' is used to describe a piercing or puncturing of the medium. That is, the generation of a hole within the medium without removal of any material from the medium. As used herein, a 'hole' within the medium may be a hole that extends through the entire thickness of the medium to form a channel. Alternatively, a 'hole' may be a hole that extends only partially through the medium.
As used herein, the term 'perforation member' is used to describe the component of the tool used to perforate the medium. In the described examples, the perforation member takes the form of an elongate body with a sharp, or needle-like end for perforating a medium. As used herein, the term 'perforation end' is used to describe the end of the perforation member, which is used to 'perforate' the medium. That is, the 'perforation end' of the perforation member is the end, which is used to generate a hole within the medium without removal of any material from the medium, for example by extending a needle, pin or sharpened end at least partially therethrough.
As used herein, the term 'counterpart' is used to describe a component of the punch tool that is (during a punching operation) located at an opposing side of the medium to be punched with relation to the punch shaft. That is, the counterpart provides a platform for the medium, while the punch shaft (and perforation member) perform the punching operation on said medium. The counterpart may also be used, in combination with the punch shaft/perforation member, to move the punched element away from the remaining medium.
As used herein, the term 'element carrier' is used to describe a component used to receive an element from the counterpart. That is, the element carrier is configured to displace the element from the counterpart. The element carrier may carry the element away from the production line (in other words carried away from the remaining medium).
As used herein, the term 'passes the element' (or the like) is used to describe the action of a transfer of position of an element from one component to another. For example, the element is considered to have been 'passed' from the counterpart to the element carrier as the counterpart travels through the element carrier. 'Passing of the element' also includes transfer of the element from the punch shaft or perforation member, for example from the perforation end of the perforation member to the element carrier.
For the avoidance of doubt, any of the features described herein apply equally to any aspect of the invention. Within the scope of this application it is expressly envisaged that the various aspects, embodiments, examples and alternatives set out in the preceding paragraphs, in the claims or in the description and drawings, and in particular the individual features thereof, may be taken independently or in any combination. Features described in connection with one aspect or embodiment of the invention are applicable to all aspects or embodiments, unless such features are incompatible.
Embodiments of the invention will now be described by way of example only with reference to the accompanying drawings in which:

Figure 1a illustrates a perspective view of a transport material;
Figure 1b illustrates a cut-away view of a transport material;
Figure 2 illustrates a perspective view of a punch tool;
Figure 3 illustrates a cut-away view of the punch tool of Figure 2;
Figure 4 illustrates a cross-section of a punch shaft of the punch tool of Figure 2;
Figure 5 illustrates a cross-section of a perforation member of the punch tool of Figure 2;
Figures 6 to 9 illustrate a cross-section of the punch tool of Figure 2 undertaking a punching operation;
Figure 10 illustrates a cross-section of another punch tool;
Figure 11 illustrates a cross-section of the punch tool of Figure 2, separating an element from a medium;
Figure 12 illustrates a cross-section of another punch tool, including a counterpart;
Figure 13 illustrates a cross-section of the punch tool of Figure 12, separating an element from a medium;
Figure 14 illustrates a cross-section of an element carrier;
Figure 15 illustrates a cross-section of another punch tool, including an element carrier;
Figures 16 and 17 illustrate the punch tool of Figure 15 in use;
Figures 18 and 19 illustrate examples of a transport material produced with the punch tool of preceding Figures; and
Figure 20 illustrates a illustrates a cross-section of a cartridge 100 of an aerosol generating system.

Referring now to Figures 2 and 3, a punch tool 200 for producing an element by punching from a medium is illustrated. The punch tool 200 includes a punch shaft 202 and a perforation member 204.
The punch shaft 202 of the punch tool 200 is illustrated in Figure 4. In this example, the punch shaft 202 includes a substantially cylindrical body portion 218 and a flange 220, at an end thereof (preferably at the non-punching end thereof).
The punch shaft 202 has a punching end 206. That is, the punch shaft 202 has an end configured to punch an element from a medium. The punching end 206 is located at an opposing end of the punch shaft 202 to the flange 220.
The punching end 206 of the punch shaft 202, includes a surface 226. In embodiments, the surface 226 of the punching end 206 may be configured to engage with a medium to be punched, such that the surface 226 punches through the medium, leaving an element that substantially corresponds in shape to the surface 226. In other words, the profile of the punching end 206 corresponds to the profile of the element to be punched.
The perforation member 204 of the punch tool 200 is illustrated in Figure 5. In this example, the perforation member 204 includes a substantially cylindrical body portion 214 and a flange portion 216 located at an end of the body portion 214. The perforation member 204 includes a needle (or pin) portion 212 located at an opposing end of the body portion 214 to the flange portion 216.
The perforation member 204 has a perforation end 208. That is, the perforation member 204 has an end configured to perforate a hole in a medium. In this example, the perforation end corresponds to the end of the needle portion 212. In this example, the perforation end 208 of the perforation member 204 is conical, whereby in use, the apex of the conical end faces outwardly towards the medium to be perforated.
As illustrated in Figures 2 and 3, the perforation member 204 is mounted within the punch shaft 228. In this example, the punch shaft 202 includes a hollow interior 228 configured to receive the perforation member 204 therein. The hollow interior includes first and second engagement surfaces 230, 232, respectively. In this example, the engagement surfaces 230, 232 are annular surfaces defining a channel therethrough, for receipt of at least a portion of the perforation member 204.
The perforation member 204 is centrally located within the punch shaft 202. That is, the perforation member 204 and the punch shaft 202, have substantially coincident longitudinal axes. The perforation member 204 is slidably mounted within the punch shaft 202. In other words, the perforation member 204 is moveable within the punch shaft 202, such that the relative position therebetween can be changed. The perforation member 204 is slidable substantially along the longitudinal axis of the punch shaft 202.
When assembled, the punch shaft 202 and the perforation member 204 are configured such that the perforation end 208 of the perforation member 204 protrudes from the punching end 206 of the punch shaft 202.
The perforation member 204 has first and second configurations relative to the punch shaft 202. In the first configuration, for use during the punching operation, the perforation end 208 of the perforation member 204 protrudes from the punching end 206 of the punch shaft 202 by a first distance. In the first configuration, the perforation member 204 may protrude from the punching end 206 by any suitable distance. In embodiments, the conical end of the perforation member 204 may only partially protrude from the punching end 206 of the punch shaft 202. In alternative embodiments, at least the entire conical end of the perforation member 204 may protrude from the punching end of the punch shaft.
In the second configuration, the perforation end 208 of the perforation member 204 protrudes from the punching end 206 of the punch shaft 202 by a second distance, greater than the first distance. The perforation member 204 is slidable, relative to the punch shaft 202, between the first and second configurations. In other words, the perforation member 204 is configured to slide within the punch shaft 202, such that the perforation end 208 of the perforation member 204 further protrudes from the punching end of the punch shaft.
In this example, the engagement surface 232, limits the protrusion of the perforation end 208 of the perforation member 204. That is, as the perforation member 204 slides within the punch shaft 202, a corresponding engagement surface 236 of the perforation member 204 (located at the intersection between the body portion 214 and the needle portion 212 of the perforation member 204) engages with the engagement surface 232 to prevent further extension of the perforation member 204 past the second configuration. In alternative embodiments, further extension of the perforation member 204 past the second configuration may instead be prevented by the maximum compression of the spring 210 (defined below).
In embodiments, the perforation member 204 is biased to its first configuration (in other words the perforation member 204 is biased away from its second configuration towards its first configuration). In such embodiments, the punch tool 200 includes a biasing means for biasing the perforation member 204 to its first configuration. In this example the biasing means is a spring 210. In the assembled punch tool, the spring 210 is located between the flange 216 of the perforation member 204 and the engagement surface 230. In this example, the spring 210 is a helically coiled spring, which allows the perforation member 204 to pass through the bore thereof. However, any suitable spring/biasing means may be used. As the perforation member 204 is actuated to slide relative to the punch shaft 202 from its first configuration to its second configuration, for example by application of a force to the perforation member 204, the spring 210 is compressed. Upon release of the applied force, the spring 210 acts to return the perforation member 204 back to its first configuration. In other words, upon release of the applied force, the spring is free to extend to its original position, returning the perforation member 204 to its first configuration in doing so.
Figures 6 to 9 illustrate the punch tool 200 performing a punching. The punching operation punches an element 310 from a medium 300.
It would be understood that the medium may be any medium from which it is required that an element is punched. In this example the medium includes an aerosol-forming substrate, for use in a consumable. Specifically, the medium is a "High-Retention-Material" (HRM), for storing fluid for the aerosol generation within the aerosol generating device. For example, the material may be natural or synthetic, including one or more of nylon, polyester, polypropylene and rayon, for example. The HRM is typically a fibrous or spongy medium, that may be stiffened to have a memory effect.
In this example, the medium is provided as a strip. The strip is conveyed on a production line. A tension is maintained in the strip to help ensure a clean punch of the element. That is an element can be punched from the medium without significant gathering of the strip, which may compromise the shape/integrity of the punched element. The strip may be supported in positions either side of the position at which the element will be punched to help ensure a clean punch of the element, for example by a die.
As a first step, the punch tool 200 is moved into engagement with the medium 300. It would be understood that the punch tool 200 would be mounted within a frame or housing (not shown), within which the punch tool 200 is moveable to perform the punching operation as required.
In this example, as the perforation end 208 of the perforation member 204 protrudes from the punching end 206 of the punch shaft 202, the perforation end 208 is the portion of the punch tool, which first engages with the medium 300, as shown in Figure 6. As the punch tool 200 is moved into engagement, the perforation member 204 is in its first configuration relative to the punch shaft 202.
As a second step, the medium is perforated. As the perforation end 208 of the perforation member 204 engages with the medium, the medium is perforated by the perforation end 208, as shown in Figure 7. During perforation of the medium, the conical end of the perforation member 208 pierces the medium. In doing so, a hole is created in the medium.
In this example the hole extends through the entire thickness of the medium to form a channel for flow of liquid aerosol-generating substrate. In other examples, the hole may extend only partially through the thickness of the medium. In examples where the hole extends only partially through the medium (or transport material), the hole does not provide a through-hole for liquid to flow through. However, it still increases the flow of liquid aerosol-generating substrate through the medium by reducing the thickness of the transport material in the region of the hole, for example to less than half of the thickness. In other words, liquid is able to permeate more easily through the remainder of the thickness of the medium compared to having to permeate through the entire thickness.
In embodiments, the conical end of the perforation member 208 is longer than the thickness of the medium, such that the medium can be perforated to create a hole that extends through the full thickness of the medium without full extension of the conical end through the medium. However, other configurations are possible if the hole is required to extend only partially through the full thickness of the medium.
As a third step, an element is punched from the medium. As the punch tool continues to move downwardly, the punching end 206 of the punch shaft 202 engages with the medium and then subsequently punches an element from the medium 300. It would be understood that the punching end 206 may be configured in any suitable way so as to punch an element from the medium when brought into engagement therewith. In embodiments, the punching end 206 may include a protrusion 234 (as shown in Figures 6 to 9), protruding from the surface 226. The protrusion 234 may be configured to engage with the medium to be punched. That is, the protrusion 234 may be configured to at least partially cut through the medium during a punching operation. The protrusion 234 may be pointed or sharpened to facilitate easier punching of the medium.
In this example, the protrusion 234 is configured to initially partially cut the medium. That is, the protrusion protrudes from the surface of the punching end 206 by a distance less than the thickness of the medium. As such, the surface 226 of the punching end 206 will engage with an upper surface of the medium as the protrusion 234 partially cuts through the medium. Further downward movement will cause the surface 226 to compress the medium, allowing the protrusion to cut through the remainder of the element perimeter, as shown in Figure 9. In another example, the protrusion 234 may protrude from the surface of the punching end 206 by a distance greater than or equal to the thickness of the medium. In this manner, the protrusion 234 cuts through the entire thickness of the medium, without compression of the medium, as shown in Figure 10.
In specific embodiments the punching operation may not involve a full cut through the thickness of the medium. For example, the protrusion may provide a substantial but not complete cut through the medium, for example leaving a ligament connecting the punched element to the medium, from which it has been punched. This ligament may be broken in subsequent handling of the medium (for example element movement using the perforation member as discussed later). That is, the protrusion is configured to partially cut the element from the medium during the punching operation. Or in other words, the protrusion initially scores the outer perimeter of the element in the medium, without providing a definitive cut through the medium.
The element that results from the punching operation described above would be in the form of that shown in Figure 1. That is an element is produced that is disc shaped with an outer diameter 102 and a central cavity with a diameter 104. The element may optionally be for use in an aerosol generating device, for example as a filter plug for an aerosol generating article. As an example, the produced element may have an outer diameter 102 of between 5 millimetres and 10 millimetres, aptly 7millimetres. The diameter of the central cavity 104 may be between 0.5 millimetres and 3 millimetres, aptly 1.5 millimetres. The thickness of the produced element may be between 0.5 millimetres and 8 millimetres, for example 4 millimetres.
Following the punching operation, the punched element is separated from the remaining medium. During separation, the punched element may be deposited elsewhere, for example on a production line for assembly operations.
In embodiments, the perforation member 208 may be used to press/displace the punched element 310 from the remaining medium 300 or the punching end 206 of the punch shaft 202 (for example if the punching end of the punch shaft has already separated the element from the medium), or both. The perforation member 204 can be actuated and brought from its first configuration relative to the punch shaft 202, to its second configuration relative to the punch shaft 202 to displace the element 310 from the punching end of the punch shaft. That is, as the perforation end 208 of the perforation member 204 further protrudes from the punching end 206 of the punch shaft 202, the conical end of the perforation member applies a downward force to the element (by virtue of the sloped surface of the conical surface) to displace the element 310, as shown in Figure 11.
It would be understood that the punch tool may be actuated to perform a punching operation in any suitable manner. In this example, the punch tool 200 is driven by at least one actuation means, for example a pneumatically or hydraulically powered cylinder.
In an example, a single actuation means may be used to vertically displace the punch tool 200 towards the medium 300. A driving surface of the actuation means may engage with the flange 216 of the perforation member 204 to drive the perforation member 204 downwardly. The stiffness of the spring 210 may be chosen so that the applied force from the actuation means is transferred to the punch shaft 202, without significant deformation of the spring. In this manner, the punch shaft 202 follows the downward movement of the perforation member 204, whilst still substantially maintaining the first configuration therebetween. The punch tool 200 traverses a distance within the frame/mount until the flange 220 of the punch shaft 202 abuts a stopping surface of the frame/mount. The position at which the vertical movement of the punch shaft 202 stops must be at least at the final position of the punching operation. That is, the punch shaft 202 may be stopped when at a position that corresponds to the completion of the punching operation. With the punch shaft 202 fixed in position by the engagement between the flange 220 and the stopping surface, further force applied by the actuation means acts to take the perforation member 204 from its first configuration to its second configuration (compressing the biasing means as it does).
In an alternative example, a first actuation means may be used to vertically displace the perforation member 204 and a second actuation means may be used to vertically displace the punch shaft 202 downwardly. The actuation process is similar to the previous example, however the progression of the perforation member from its first configuration to its second configuration can be achieved by separate actuation (or actuation to a different extent) of the first and second actuation means.
Following removal of the applied force to the perforation member 204, the perforation member 204 returns to its first configuration relative to the punch shaft 202 by way of the biasing force from spring 210.
In embodiments, for example that shown in Figure 12, the punch tool 200 includes a counterpart 400. During the punching operation, the counterpart 400 is located on an opposing side of the medium relative to the punch shaft 202. Specifically, the medium 300 is positioned between the punch shaft 202 (and also the perforation member 204) and a mating portion 402 of the counterpart 400. The mating portion 402 of the counterpart 400 is located adjacent to (in other words it engages with) an opposing side of the medium 300 relative to the punch shaft 202. That is, the mating portion 402 of the counterpart 400 is configured to be located adjacent to the portion of the medium 300 from which the element is to be cut.
The counterpart 400 has an aperture 404 configured to receive the perforation end 208 of the perforation member 204. As shown in Figure 13, as the perforation end 208 of the perforation member 204 perforates the medium 300, the perforation end extends into the aperture 404. In the illustrated example, the aperture 404 is a channel, extending longitudinally through the counterpart 400. However, it would be understood that the aperture may be an indent, that only partially extends longitudinally through the counterpart.
In this example, the mating portion 402 of the counterpart 400 substantially corresponds in shape to the punching end 206 of the punch shaft 202. In this example, the mating portion 402 of the counterpart 400 is smaller in cross-section than the punching end of the punch shaft. In other words, for a circular punching end, configured to punch an element of a given diameter, the diameter of the mating portion 402 of the counterpart 400 is smaller than that of the punching end and hence also the produced element.
The mating portion 402 of the counterpart 400 provides a surface, that allows the medium to be supported during the punching operation (as described above). In embodiments, the counterpart 400 may also be used in combination with the perforation member 204 (and optionally also the punch shaft 202) to move the punched element 310, for example onto a production line for assembly operations.
Following the punching operation, as the perforation end 208 of the perforation member 204 protrudes further from the punching end 206 of the punch shaft 202 (in other words the perforation member 204 moves to its second configuration) the counterpart 400 moves away from the medium. That is, the downward movement of the counterpart 400 corresponds with the downward movement of the perforation member 204. In this manner the punched element 310 is moved away from the remaining medium 300, whilst being supported between the perforation end 208 of the perforation member 204 and the mating portion 402 of the counterpart 400, as shown in Figure 13.
In alternative embodiments, the punch shaft 202 and the perforation member 204 initially both move downwardly with the counterpart 400, to carry the element 310 away from the remaining medium 300. The perforation member 204 is subsequently actuated to its second configuration, to carry the element 310 further with the counterpart 400 as described above.
The counterpart 400 may be actuated in any suitable manner. For example, the counterpart 400 may be driven by an actuation means, for example a pneumatically or hydraulically powered cylinder. Alternatively, the counterpart 400 may be driven by the downward movement of the perforation member 204.
Following the punching operation, the punch tool may be re-set to its original configuration. The medium 300 may then be moved between the punch shaft 202 and the counterpart 400, across the path of the punch shaft 202. In this manner, an area of the medium 300, from which an element is yet to be punched may be positioned directly between the punch shaft 202 and the counterpart 400 and a new punching operation may begin.
In specific embodiments, the punch tool 200 further includes an element carrier 500, configured to receive the element 310 from the counterpart 400. In this example, the element carrier 500 has an aperture 504. The aperture 504 is configured to allow the counterpart 400 therethrough, such that a portion of the counterpart 400 is within the element carrier 500. That is, the aperture 504 is sufficiently large so as to allow the counterpart 400 to extend therethrough. In this example, the diameter 502 of the aperture is larger than the diameter of the counterpart.
The aperture 504 of the element carrier 500 is smaller than the punched element. That is, the aperture 504 is sufficiently small so as to prevent the punched element from passing therethrough. Specifically, in this example the diameter 502 of the aperture is smaller than the diameter 102 of the punched element.
In this example, the element carrier 500 includes a channel extending therethrough. In other words, the element carrier 500 is substantially tubular in shape, as shown by the cross-section in Figure 14. The aperture 504 forms a restricted portion (to act as an element seat as described later) within the channel. In alternative examples, the aperture 504 may extend through the entirety of the element carrier 500. In such examples, the received element will sit on top of the element carrier 500.
The element carrier 500 may be made from any suitable material, for example a polymeric or metal material. In specific embodiments the element carrier is made of plastic.
During the punching operation, the element carrier 500 is located on an opposing side of the medium 300 relative to the punch shaft 202. Specifically, the element carrier is located on the same side of the medium as the counterpart 400.
The counterpart 400 has a first, extended, configuration relative to the element carrier 500. In the extended configuration, the counterpart 400 extends through the aperture 504 and is positioned within the element carrier 500, as shown in Figure 15. The counterpart 400 has a second, retracted, configuration relative to the element carrier 500. In the retracted configuration, the counterpart 400 does not extend through the aperture 504, as shown in Figure 17.
The counterpart 400 moves from its extended configuration to its retracted configuration as the perforation member 204 extends from its first configuration to its second configuration, as shown by the progressive configurations in Figures 16 and 17. That is, the counterpart 400 is moveable through the element carrier 500. The perforation end 208 of the perforation member 204 protrudes further from the punching end 206 of the punch shaft 202 as the counterpart 400 moves through the element carrier 500.
As the counterpart 400 is retracted (that is, the counterpart 400 is moved from its extended configuration to its retracted configuration), the element 310 is passed to the element carrier 500 (or to put differently, the element is stripped from the counterpart / punch shaft / perforation member). In other words, the element 310 is carried away from the medium 300 by the perforation member 204 and the counterpart 400. As the counterpart 400 moves through the element carrier 500, the element 310 is prevented from passing entirely through the element carrier 500 by the aperture 504. As the counterpart 400 continues to move through the element carrier 500, the element 310 is displaced from the mating portion 402 of the counterpart by the aperture 504. The perforation member is then released to its first configuration (as shown by Figure 17).
It should be noted that the above described operations (for example perforation, punching, carrying of the element, deposition of the element on the element carrier 500) may all occur with movement of the punch tool (or components thereof) in a single linear direction. This allows for an efficient production process. That is, the element 310 can be perforated, punched and then passed to the element carrier 500 in a controlled manner. This ensures fast and efficient production and subsequent utilization of the punched elements 310.
In embodiments, once the element 310 is 'captured' by the element carrier 500 (that is the element 310 is passed to the element carrier 500), the element carrier 500 (with the element 310 thereon) is replaced with an empty carrier element 500. In alternative embodiments, the element carrier 500 acts to deposit the element 310 in a further location before returning to its original location to capture a further element 310.
Various modifications to the detailed arrangements as described above are possible. For example, it would be understood that the specific configurations of the punch shaft 202 and the perforation member 204 are given as an example only. That is, punch shaft 202 (the interior and exterior thereof) and perforation member 204 may be any suitable shape to allow them to interact and function in the required manner. Similarly, the proportions or dimensions of the described components (for example the diameter of the perforation member 204) may be any suitable value.
The perforation member 204 may be configured to rotate during perforation of the medium 300. In embodiments, the conical perforation end 208 may be threaded to assist in perforating the medium.
In embodiments, the protrusion 234 may be configured as a number of discrete protrusions rather than a single continuous protrusion. That is, the protrusions may act to perforate the medium 300 prior to the punching operation being completed upon engagement between the medium 300 and the surface 226 of the punch shaft 202.
The second (extended) position of the perforation member 204 may involve any suitable amount of extension. The amount of extension of the perforation member 204 may depend on the range of movement of the counterpart 400, or the position of the element carrier 500, or both the range of movement of the counterpart 400 and the position of the element carrier 500.
In this example, the punching end 206 (or more particularly the surface 226 thereof) of the punch shaft 202 is circular. In this manner, a circular element 310 will be produced by a punching operation using a circular punching end 206 (or a punching element with a circular protrusion, or both). It would be understood that in other embodiments the profile of the punching end 206 (or the protrusion thereon) may be of any shape, in order to punch an element 310 of said shape. For example, the punching end 206 may have an oval or square profile.
In embodiments the mating portion 402 of the counterpart 400 is a flat surface, to allow the medium 300 (and subsequent element 310) to sit thereon. In alternative embodiments, the mating portion 402 of the counterpart 400 has a camber around its periphery (in other words the edge of the mating portion 402 may curve downwardly or be angled downwardly). In this manner, as the punch shaft 202 engages with the medium 300, to punch an element 310 therefrom, the subsequent element 310 may deform around the mating portion 402 to prevent subsequent movement of the element 310 therefrom.
Figures 18 illustrates an example of an element 224 having first and second surfaces 224a and 224b resulting from a punching operation described herein. In this example the elements have a convex surface (for example convex first surface 224a), in particular a convex dome shape. This shape may result from the punching operation described above, with the applied punching and perforation force tending to bow the surface outwardly. Alternatively, this shape may be added (or emphasised) to the element by forcing it through a mould. The curved surface may be beneficial in helping the element conform to the shape of a curved fluid permeable heating element. In the example of Figure 18 the tapered hole 280 passes through the entire thickness of the transport material 224. The further example of Figure 19, the element 324 is similar to that of Figure 18 with the exception that the hole 326 extends only partially through the thickness of the transport material 324.
The punch tool 200 and the method described above is suitable for a scaled-up operation. For example, the punch tool 200 may form part of a system for producing a plurality of elements 310 by punching from a medium 300. In such embodiments the system includes a plurality of punch tools 200. The punch tools 200 may be arranged in series or parallel with respect to the direction of travel of the medium 300 (in other words the punch tools 200 may be arranged across a width or length of the medium), such that a plurality of elements may be punched simultaneously.
It will also be appreciated by those skilled in the art that any number of combinations of the aforementioned features or those shown in the appended drawings provide clear advantages over the prior art and are therefore within the scope of the invention described herein.
The schematic drawings are not necessarily to scale and are presented for purposes of illustration and not limitation. The drawings depict one or more aspects described in this disclosure. However, it will be understood that other aspects not depicted in the drawings fall within the scope of this disclosure.

Claims

A punch tool for producing an element by punching from a medium, comprising:
a punch shaft having a punching end; and

a perforation member having a perforation end, the perforation member being mounted within the punch shaft,

wherein the perforation end of the perforation member protrudes from the punching end of the punch shaft;

wherein the punch tool is configured such that during a punching operation, the perforation end of the perforation member perforates the medium, prior to the punching end of the punch shaft punching an element from the medium.
A punch tool as claimed in claim 1, wherein the punch tool further comprises a counterpart, wherein during the punching operation, a mating portion of the counterpart is located adjacent to an opposing side of the medium relative to the punch tool.
A punch tool as claimed in claim 2, wherein the counterpart has an aperture configured to receive the perforation end of the perforation member.
A punch tool as claimed in any preceding claim, wherein the mating portion of the counterpart is smaller in cross-section than the punching end of the punch shaft.
A punch tool as claimed in any of claims 2 to 4, wherein the punch tool further comprises an element carrier, configured to receive the element from the counterpart.
A punch tool as claimed in claim 5, wherein the element carrier has an aperture configured to allow the counterpart therethrough, such that a portion of the counterpart is within the element carrier.
A punch tool as claimed in claim 6 in which the aperture of the element carrier is smaller than the element.
A punch tool as claimed in any preceding claim in which the punching end of the punching shaft has a protrusion configured to at least partially cut the element from the medium during the punching operation.
A punch tool as claimed in any preceding claim in which the perforation end of the perforation member is conical.
A punch tool as claimed in any preceding claim in which the perforation member is centrally located within the punch shaft.
A punch tool as claimed in any preceding claim, wherein the perforation member is slidably mounted within the punch shaft.
A punch tool as claimed in any of claims 5 to 7, wherein the counterpart has a first, extended, configuration relative to the element carrier and a second, retracted, configuration relative to the element carrier,
wherein in the extended configuration, the counterpart extends through the aperture and is positioned within the element carrier, and
wherein in the retracted configuration, the counterpart does not extend through the aperture.
A punch tool as claimed in claim 12, wherein the perforation member has first and second configurations relative to the punch shaft;
wherein in the first configuration, for use during the punching operation, the perforation end of the perforation member protrudes from the punching end of the punch shaft by a first distance;
wherein in the second configuration the perforation end of the perforation member protrudes from the punching end of the punch shaft by a second distance, greater than the first distance.
A system for producing a plurality of elements by punching from a medium, the system comprising:
a plurality of punch tools according to any preceding claim.
A method of working a punch tool, the method comprising the steps of:
providing a medium, from which an element is to be punched;

providing a punch tool, the punch tool comprising
a punch shaft having a punching end; and

a perforation member mounted within the punch shaft, wherein a perforation end of the perforation member protrudes from the punching end of the punch shaft;

moving the punch tool into engagement with the medium to perform a punching operation to produce an element, the punching operation comprising:
perforating the medium with the perforation end of the perforation member,

and then punching an element from the medium with the punching end of the punch shaft.