Catheter for liquid dispenser, method of manufacture and use thereof

Abstract

A conduit for a liquid dispenser (1) comprises a pipe (20) for carrying a liquid and a heating device (19) for heating at least one section of the pipe (20). The heating device comprises means (31) for fixing the heating device (19) to the pipe (20). The component (31) is a component injection molded on the pipe (20) along at least a length of the pipe (20).

Description

[0001] Divisional application

[0002] This application is a divisional application. The application number of the original application is 201910346502.2, the application date is April 26, 2019, and the name of the invention is “Conduit for liquid dispenser, its manufacturing method and its use”. Technical Field

[0003] The present invention relates to a conduit for a liquid distributor, comprising: a tube for carrying liquid; and a heating device for heating at least a section of the tube; wherein the heating device comprises means for fixing the heating device to the tube.

[0004] The invention also relates to a method for manufacturing a conduit for a liquid distributor, such as the conduit described above, the method comprising: providing a pipe for carrying the liquid; and fixing a heating device for heating at least a section of the pipe to the pipe.

[0005] The invention also relates to a dispenser.

[0006] The invention also relates to the use of a conduit for a liquid distributor. Background Art

[0007] EP 0 284 669 A1 discloses a heat-insulating connector for a heatable hose for a motor vehicle windscreen waste nozzle. At the free end of the hose, a heating conductor is exposed by removing the hose wall, and the exposed length is wrapped around the hose portion protruding from the inner cavity of a connector or dispenser component. The region of the hose end with the protruding portion of the connector element, including the covered heating conductor, is then encapsulated in an insoluble block element with a sheath of insulating material, from which the heating conductor connector emerges.

[0008] US2013 / 336643A1 describes a pipeline connector having a connector with at least one joint portion for connecting to a medium pipeline or component in a motor vehicle. The connector includes a transition portion adjacent to the joint portion and a flow duct. At least in the region of the transition portion, an electric heating element for the medium pipeline is provided, arranged at least partially around the flow duct. The connector and the heating element are surrounded by an outer sheath. At least one joint portion is designed as a hollow cylindrical container for direct insertion into the end of a medium pipeline, enabling the medium pipeline to be fastened in a material-integrated manner. The joint portion comprises a material transparent to the laser beam, at least in multiple regions, so that the medium pipeline can be fastened by laser welding.

[0009] KR 100 948 782 B1 discloses a pipe joint using a pressure wheel, a method for manufacturing the same, and a pipe connection structure having the pipe joint, which is configured to prevent damage or separation of the pipe at the pipe joint due to a sudden increase in water pressure. The pipe joint comprises a fixing pipe inserted into the inner circumference of one side of the pipe joint, a connecting pipe, an annular mounting groove formed on the inner circumference of the other side of the pipe joint for mounting a connecting ring for fixing the connecting pipe, and a pressure wheel. The annular mounting groove is formed on the inner circumference of the other side of the pipe joint for mounting a connecting ring for fixing the connecting pipe. The pressure wheel secures the connecting pipe in place by press-fitting the connecting ring. DE 203 01 999 U1 discloses a device for preventing bacterial accumulation on a drinking fountain for human consumption. The dispensing opening and / or an area of the dispensing opening is electrically heated to prevent retrograde bacterial accumulation. The electrical heating can be achieved in various ways, for example, by means of a sleeve having an electrically heated coil embedded therein, wherein the sleeve provides thermal insulation and mechanical support. The sleeve surrounds the end of the water supply pipe. Alternatively, the heating coil may be integrated into the conduit such that an annular groove is formed in the conduit wall, thereby forming a space for inserting the heating coil, wherein the space may be filled with an insulating lining, wherein the heating coil is embedded therein.

[0010] A problem with both alternatives is that if the coil is inserted into an annular groove that is subsequently filled with insulating material, heat transfer to the tube may be suboptimal due to the movement of the winding away from the tube. Variants with sleeves may have the same problem unless additional devices such as screw clamps are provided. Even then, the screw clamps may loosen over time. Summary of the Invention

[0011] It is an object of the present invention to provide a conduit, a method for its manufacture, a distributor and a use of a conduit in which the heating device is reliably maintained in a relatively close relationship to the conduit.

[0012] According to a first aspect, this object is achieved by a catheter according to the invention, characterized in that the component for fixing the heating device to the pipe is a component which is injection-moulded on the pipe along at least a length of the pipe.

[0013] Injection-molded components can be identified, for example, by the injection point and one or more parting lines on the component. During the injection molding process, the cavity between the mold and the pipe is filled with material under pressure, which ensures that the heating device is pressed close to the pipe. As a result, a relatively reliable connection is formed with relatively few components. The conduit is suitable for use as a flow-through heater or, more preferably, as a barrier to prevent retrograde bacterial contamination in beverage dispensers. Retrograde contamination refers to the migration of bacteria from the outlet nozzle of the dispenser in the opposite direction of the liquid flow during use.

[0014] In one embodiment, the injection molded part is arranged around the duct.

[0015] The injection-molded component can completely surround the pipe or be interrupted only by one or more radially extending separators, for example, if the injection-molded component is electrically conductive. The heating device is thus secured to the pipe externally, so that, during use, only the material of the pipe comes into contact with the liquid being dispensed. This allows the heating device to be made of materials that are not necessarily certified as safe for food contact. Furthermore, the inner surface of the pipe can be relatively smooth, in particular, free of grooves in which liquid could become trapped.

[0016] In one embodiment, the injection molded part is made of at least one polymer material.

[0017] The injection molded part can be made from a blend of polymeric materials. It can be a composite of one or more polymeric materials and one or more other materials (e.g., reinforcing fibers). The material of the injection molded part will generally have good heat resistance. A suitable material is polyphenylene sulfide, optionally reinforced with glass fibers.

[0018] In one embodiment, the heating device is an electric heating device.

[0019] This allows temperature control or regulation, since the electrical power supplied to the electrical heating means can be regulated.For example, the heating means may comprise an induction heater or a thermoelectric heating means.

[0020] A variation of this embodiment includes at least one electrical connection lead, a section of which is embedded in the injection-molded part.

[0021] The injection-molded component thus shields at least the embedding section and ensures that one or more electrical connection leads are relatively unlikely to become attached.

[0022] In a particular variant, the section is an end section which is in electrically conductive contact with the terminal.

[0023] The terminal may be the end of a heating wire or an electrical connector (eg, a ferrule, etc.) Soldering may generally be omitted in this embodiment.

[0024] In a variant where the heating device is an electric heating device, the conduit comprises a separator arranged between the conductive part of the heating device and the pipe, wherein the separator is made of a material having a higher resistivity than the conductive part.

[0025] In this embodiment, the conduit can be made of metal. The conductive portion can be held in relatively close relationship to the conduit by the injection molded component, or the injection molded component itself can be conductive. The separator can prevent short circuits.

[0026] In the variant where the heating device is an electric heating device, the heating device comprises a resistive heating element.

[0027] In use, the heat generated by the resistance heating element is transferred to the pipe. The pipe can be made of a suitable thermally conductive material that is also certified for contact with liquids intended for human consumption. These materials typically do not include alloys best suited for induction heating. The injection-molded component isolates the resistance heating element from the environment and maintains it in a thermally conductive relationship.

[0028] In a particular variation thereof, the resistive heating element has a positive temperature coefficient.

[0029] In this embodiment, (local) overheating is prevented without fine temperature control.The resistivity increases with increasing temperature, for example exponentially, in order to limit the heat generated.

[0030] In a particular embodiment in which the heating device is an electric heating device comprising a resistive heating element, the resistive heating element is comprised in a component which is injection moulded onto the pipe.

[0031] This embodiment has very few parts. Assembly is simplified, and there are fewer interfaces that could potentially restrict heat conduction.

[0032] In another variation of the embodiment in which the heating device is an electric heating device comprising a resistive heating element, the resistive heating element comprises a wound heating wire.

[0033] This embodiment is easier to assemble than the variant comprising a heating foil. Special terminals for connecting the foil to the power supply leads can be omitted. The heating wire is relatively easy to position.

[0034] In a particular variant thereof, the catheter further comprises a carrier, wherein the heating wire is wound around the carrier, and wherein the carrier is arranged between the pipe and the injection-molded component.

[0035] The carrier facilitates winding the heating wire and holding it in place during the injection molding process. The number of turns of the heating wire can be relatively evenly distributed, thereby preventing local overheating during use. In addition, the carrier can have a relatively simple shape, for example, basically the shape of a spool around which the heating wire is easily wound. In contrast, the pipe can have a shape that is not very suitable for winding the heating wire directly onto it. Before the injection molding process, such a carrier can be slid onto the pipe with the heating wire already in place. The carrier can also help to electrically insulate the heating wire from the pipe, although the heating wire is usually also provided with some form of insulating coating or cladding.

[0036] In a variation of this embodiment, the carrier is provided with a flange at at least one end.

[0037] The one or more flanges facilitate placement of the heating wire and hold it in place.

[0038] In an embodiment of an electric heating device in which the heating device is a resistive heating element comprising a wound heating wire, the heating wire is a heating wire coated with an electrically insulating material.

[0039] This allows the turns of the heating wire to be positioned close together, eg with adjacent turns touching each other.

[0040] In another embodiment, the material or mass of the injection molded component itself includes a conductive material or compound. Such a conductive material or compound includes a polymer having a conductive material (such as carbon black or steel fiber) dispersed therein. Suitable materials include PTC rubber, a compound made of polydimethylsiloxane loaded with carbon nanoparticles, or carbon fiber reinforced polyphenylene sulfide (PPS). Typically, these materials have a specific resistance of 0.001 to 250 mΩ at 25°C.

[0041] In this embodiment, a carrier or alternative separator having a higher resistivity than the injection molded material separates the conductive material or compound from the tubing to prevent short circuits.

[0042] This allows the production of components of the catheter according to the invention in a multi-component injection molding process, wherein in one production step the injection-molded component is formed from a conductive material or compound and the carrier is formed from a material or compound having a higher resistivity. In one embodiment of the catheter, at least one section of the tubing is straight, the at least one section of the tubing extending in the longitudinal direction from one end of the tubing to at least one end of the heating device remote from this end of the tubing.

[0043] This embodiment allows the heating device, or a portion thereof, to be slid onto the pipe during manufacture before being secured during the injection molding process. The portion that is slid onto the pipe can have an inner diameter that corresponds to the outer diameter of the straight pipe section within a certain tolerance range, so that the heating device can be clamped relatively tightly to the pipe.

[0044] In one embodiment, the conduit is made of metal, such as stainless steel.

[0045] This embodiment has good thermal conductivity. Stainless steel is suitable for contact with liquids intended for human consumption.

[0046] In one embodiment, the conduit has a circular cross-section.

[0047] If the hollow interior of the pipe has a circular cross section transversely to the longitudinal direction corresponding to the flow direction, stagnation zones are largely avoided. If the exterior of the pipe has a circular cross section transversely to the longitudinal direction, the injection molded part can clamp the heating device to the pipe relatively evenly.

[0048] In one embodiment, the pipe is provided with at least one groove, such as a circumferential groove, for engaging the joint.

[0049] Thus, the conduit can be relatively short, for example, essentially forming the outlet of the distributor. The conduit can be connected to a conduit made of a different material via a joint. Such a conduit can be, for example, a flexible conduit, which will be easier to arrange within a relatively compact distributor housing.

[0050] In one embodiment, the injection-moulded part comprises at least one feature arranged to cooperate with a feature of a separate component of the heating device to lock the separate component to the injection-moulded part.

[0051] Thus, separate fasteners can be omitted. Components that are less able to withstand the conditions prevailing during the injection process can be attached later.

[0052] In a variation of this embodiment, a separate component encloses a space housing another component of the heating device.

[0053] The other component is relatively well protected and may be a component that is installed after injection molding.

[0054] In one embodiment of the conduit, the heating device further comprises a component arranged in a thermally conductive relationship with at least one of the injection molded part and the conduit.

[0055] This component can be a temperature sensor or a fuse to provide overheating protection.

[0056] In a variation of one embodiment, the injection-molded part further comprises at least one feature arranged to cooperate with a feature of a separate component of the heating device to lock the separate component to the injection-molded part, the component being arranged in a thermally conductive relationship with at least one of the injection-molded part and the conduit and being clamped thereto by locking the separate component to the injection-molded part.

[0057] According to another aspect of the invention, the method for manufacturing a conduit for a liquid distributor is characterized in that the step of fixing the heating device comprises placing at least the conduit in a mold and injection molding a portion of the heating device over at least a length of the conduit.

[0058] The heating device is thus fixed in place and close to the pipe using relatively few components.

[0059] According to another aspect of the present invention, there is provided a dispenser for dispensing a liquid, comprising a conduit according to the present invention.

[0060] In one embodiment, the conduit forms the dispensing outlet.

[0061] The conduit is arranged so that the liquid is dispensed directly through the outlet at the free end of the conduit. Once the liquid leaves the conduit, there is no contact between the liquid and the rest of the dispenser.

[0062] One embodiment of the distributor further includes a connector connecting the conduit to the manifold and one of the additional conduits.

[0063] The additional conduits or manifolds can be made of different materials via joints. Examples of such conduits include flexible tubing, which is easier to arrange within a relatively compact distributor housing. The additional conduits or manifolds may conduct heat more poorly than the pipes.

[0064] In an embodiment of the dispenser, the heating means are electric heating means and the dispenser comprises power control means for supplying electric power to the heating means.

[0065] The temperature of the pipe section heated by the heating device can thus be controlled or regulated relatively well.

[0066] In a variation of this embodiment, the power control means is arranged to supply electrical pulses to the electrical heating means at intervals, for example pulses having a duration in the order of seconds.

[0067] The heating level can be set by selecting the duration of the pulse. Using a relatively low pulse frequency helps to avoid electromagnetic compatibility problems and noise. Alternatively, conventional pulse width modulation can be used.

[0068] In a variant of the embodiment, the power control device is arranged to supply electrical pulses to the electric heating device at certain intervals, and the variant also includes at least one temperature sensing device for providing a temperature signal, wherein the power control device is arranged to supply electrical pulses to the electric heating device according to a scheme selected from a plurality of predefined alternative schemes based on the temperature signal.

[0069] Thus, closed loop control is not required, but an appropriate temperature can still be achieved. In one embodiment, the temperature sensing means may be arranged to sense the ambient temperature. In an alternative embodiment, the temperature sensing means may be arranged to sense the temperature of a pipe or a heating device.

[0070] According to another aspect, the present invention provides the use of a catheter according to the invention for combating retrograde contamination in a liquid dispenser.

[0071] While alternative uses such as flow-through heaters are conceivable, the use against retrograde contamination is more readily achieved using a low voltage power supply. In this application, the pipe is locally heated to create a thermal barrier to prevent contamination from traveling upstream. BRIEF DESCRIPTION OF THE DRAWINGS

[0072] The present invention will be explained in further detail with reference to the accompanying drawings, in which:

[0073] Figure 1 is a front view of the dispenser;

[0074] Figure 2 is a schematic diagram showing selected components of a dispenser;

[0075] Figure 3 is a perspective view of a conduit provided with a heating device and included in a distributor;

[0076] Figure 4 yes Figure 3 A plan view of the catheter;

[0077] Figure 5 yes Figure 3 and Figure 4 a cross-sectional view of a catheter;

[0078] Figure 6 yes Figure 3-5 Another cross-sectional view of the catheter;

[0079] Figure 7 is a cross-sectional view through the conduit and cover of the heating device;

[0080] Figure 8 is a schematic diagram illustrating pulses supplied to the heating device in use; and

[0081] Figure 9 is a flow chart illustrating steps in a method of manufacturing a catheter.

[0082] List of reference numerals:

[0083] 1-Distributor

[0084] 2- Shell

[0085] 3- User Interface

[0086] 4-grooves

[0087] 5-Exit

[0088] 6-Inlet connector

[0089] 7-Filtration system

[0090] 8-Manifold

[0091] 9-Pump

[0092] 10-Cooler

[0093] 11-Air supply valve

[0094] 12-Gas Container

[0095] 13-Outlet duct

[0096] 14-Connection connector

[0097] 15-Interconnecting conduits

[0098] 16-Controller

[0099] 17-Temperature sensor

[0100] 18-Power control device

[0101] 19-Heating device

[0102] 20-Pipeline

[0103] 21-Cylindrical section

[0104] 22-Exit section

[0105] 23-Bend section

[0106] 24-groove

[0107] 25a, 25b - Leads

[0108] 26-Thermal Fuse

[0109] 27-Heating wire

[0110] 28-Carrier

[0111] 29-Upstream flange

[0112] 30-Downstream flange

[0113] 31-Injection molded parts

[0114] 32a, 32b - pawl

[0115] 33-cover

[0116] 34a, 34b-terminal

[0117] 35a-35f-Pulse

[0118] 36-Step (Pipeline Roughening)

[0119] 37-Step (Wrapping the Heating Wire)

[0120] 38-Step (Sliding the Carrier onto the Pipe)

[0121] 39-Step (Put into the mold)

[0122] 40-step (injection molding)

[0123] 41-Step (Removing from the Mold)

[0124] 42-Step (Connecting the Thermal Fuse)

[0125] 43-Step (Attaching the Cover). DETAILED DESCRIPTION

[0126] The dispenser 1 for dispensing beverages is shown in the form of a tabletop device ( Figure 1 ). It is envisaged that the dispenser shown is used to dispense various forms of treated aqueous beverages, in particular treated drinking water. Such dispensers are also known as water bars. The illustrated dispenser 1 is configured for dispensing filtered water, cold water and cooled sparkling water, for example with a selectable concentration of carbon dioxide, at ambient temperature. In other embodiments, the dispenser 1 may further or alternatively be configured to dispense untreated tap water, boiling water or hot water (for example, at a temperature above 90°C). Other versions, such as floor-standing devices, are also possible.

[0127] Dispenser 1 includes a housing 2 and a user interface 3 for selecting the type of beverage to be dispensed. A recess 4 is provided for placing a vessel beneath outlet 5 to collect the beverage. For example, the vessel can be a drinking cup or bottle. As will be explained, this prevents retrograde bacterial contamination via outlet 5. This type of contamination occurs through contact with outlet 5, whereby bacteria migrate to and spread within outlet 5. Minimizing the risk of this contamination makes dispenser 1 suitable for use in settings such as waiting rooms in doctors' surgeries.

[0128] Distributor 1 includes ( Figure 2 ) inlet connector 6 for connecting the dispenser to a source of drinking water (e.g. tap water). It also includes a filtration system 7. The filtration system 7 may be, for example, a combination of a replaceable filter cartridge and a filter head. The types of treatment performed by the filtration system may include mechanical filtration, including membrane filtration by treatment with ion exchange resins, softening or decarbonation (carbonate hardness reduction), other types of adsorption, including treatment with activated carbon or heavy metal scavengers, and combinations thereof. The filtration system 7 may also be arranged to treat the water, for example by elution, to adapt its mineral content.

[0129] The filtration system 7 is connected via a pump 9 to a manifold 8 provided with solenoid valves (not shown separately). The manifold 8 is arranged to direct water to a cooler 10 containing a carbonator (not shown separately), so that the water is cooled, or cooled and carbonated. A gas supply valve 11 controls the delivery of carbon dioxide from a gas container 12, which may also be a replaceable cartridge, to the carbonator.

[0130] The treated water returns to manifold 8, where one or more valves are located to control its delivery to outlet conduit 13. Outlet conduit 13 is a separate component connected via connector 14 to interconnecting conduit 15 extending from manifold 8. For example, interconnecting conduit 15 may be flexible tubing. Consequently, outlet conduit 13 can be relatively short, making it easier to manufacture. Furthermore, outlet conduit 13 can be made of a different material, particularly a material that conducts heat better than the material of interconnecting conduit 15.

[0131] The operation of the dispenser 1 is controlled by a controller 16. The controller 16 is provided with a measurement signal from a temperature sensor 17. The controller 16 also directs the operation of a power control device 18, which is arranged to supply power to a heating device 19 of the outlet duct 13. The heating device 19 is arranged to heat a portion of the outlet duct 13 to create a thermal barrier to prevent or at least combat retrograde contamination.

[0132] The outlet conduit 13 includes a pipe 20 made of a material that conducts heat relatively well, such as metal. The pipe 20 can be made of stainless steel certified for contact with beverages. The pipe 20 can have a wall thickness of less than 1 mm, for example, between 0.5 and 1 mm. The pipe 20 includes a substantially straight cylindrical portion 21 that transitions into an outlet section 22 via a curved elbow section 23. The curved section 23 has a substantially constant radius of curvature. In use, the cylindrical section 21 can be oriented substantially horizontally, with the outlet section 22 cantilevered downward. This reduces the overall height of the dispenser 1. The heating device 19 does not need to be located above the outlet section 22. The absence of unnecessary bends avoids stagnant zones, further helping to prevent contamination. Due to the curved section 23, the outlet section 22 is at a lower level than the sections 21 at the opposite end of the pipe 20, so that at the end of each dispense, the pipe 20 is essentially empty of water.

[0133] On the outside of the cylindrical section 21 there are grooves 24 provided which allow for a positive lock with the connector 14. In other embodiments features of alternative shapes may be used which fulfil the same function of cooperating with the connector 14 to provide a positive lock.

[0134] The leads 25a, 25b provide an electrical connection between the power control means 18 and the heating means 19. The leads 25a, 25b are provided with an insulating covering and are arranged to withstand temperatures up to at least 200°C.

[0135] The end of the first lead 25a is crimped to the wire portion extending from the thermal fuse 26 ( Figure 7The end of the second lead wire 25b is crimped to a heating wire 27 arranged in a coil on a carrier 28. The heating wire 27 is coated with an electrically insulating coating, such as polytetrafluoroethylene, so that adjacent turns of the heating wire 27 can contact each other.

[0136] The carrier 28 is usually in the form of a bobbin ( Figure 5 、 Figure 6 ). It is provided with flanges 29, 30 for positioning the wound heating wire 27. Therefore, the heating wire 27 can be relatively easily wound onto the carrier 28. For example, the carrier 28 can be made of an electrically insulating material.

[0137] The carrier 28 is secured to the pipe 20 by a mass 31 of injection-molded material, which clamps it to the pipe 20. This also presses the heater filament 27 close to the carrier 28. Because the heater filament 27 is arranged for resistive heating, relatively good heat transfer is achieved. The injection-molded material also encapsulates the connection between the lead 25b and the heater filament 27 and generally shields the heater filament 27 from the environment.

[0138] In one embodiment, a mass 31 of injection molded material may be overmolded to extend to the outer surface of the pipe 20 at at least one end of the heating device 19. This creates a bond that further helps secure the heating device 19 to the pipe 20.

[0139] The injection moulding material may be a composite material such as glass fibre reinforced polyphenylene sulphide. An example is available from Ticona GmbH under the trademark Fortron 1130L4.

[0140] The carrier 28 and the mass 31 of injection-molded material may have the same material composition.

[0141] The mass 31 of injection molded material has at least one molded feature on its exterior. In the example shown, this includes detents 32a, 32b ( Figure 3 、 Figure 5 ) are provided. The cover 33 serves as a fixture to compress the thermal fuse 26 into contact with the flange 30 in the illustrated embodiment, or to compress the thermal fuse 26 into contact with the mass 31 of injection molded material in an alternative embodiment. The cover 33 further encloses the space housing the thermal fuse 26 and the terminals 34a, 34b that connect it to the heater wire 27 and the lead 25a.

[0142] In the embodiment shown, the thermal fuse 26 is an irreversible thermal fuse 26. In an alternative embodiment, it is replaced by a temperature sensing device for conducting a signal to the controller 16.

[0143] In use, the power control device 18 is arranged to provide electrical pulses 35a-35f to the heating device 19. The voltage of the pulses 35a-35f can be, for example, 12V or 24V. The pulses 35a-35f have different durations depending on the protocol. The controller 16 is configured to select a protocol from a plurality of predefined protocols based on at least one value of a measurement signal provided by the temperature sensor 17. The temperature sensor 17 can, for example, be located in close proximity to or in thermal contact with different portions of the pipe 20 or outlet conduit 13. The duration of at least the first pulse 35a is longer than the duration of at least the final pulse of the sequence corresponding to the protocol. The sequence can have a finite duration and be triggered by events such as user interaction with the user interface 3, activation of the main power switch (not shown) of the dispenser 1, or the lapse of time since the last pulse sequence was provided. The triggering of the pulse sequence can be temperature-dependent, for example, causing the heating device to operate more frequently at higher ambient temperatures.

[0144] The pulse frequency is relatively low, with at least the longest pulse 35a having a duration of at least one second, thereby avoiding electrical interference and noise.

[0145] The heating device 19 is operated so that the temperature of the section of the pipe 20 along which the heating device 19 is arranged is kept below 100° C., for example below 90° C. This is sufficient to create a thermal barrier while preventing or at least reducing scaling in the pipe 20. The outlet section 22 is kept below 50° C. to prevent burns if a user accidentally touches the outlet 5.

[0146] Make the outlet conduit 13 ( Figure 9 ) includes an optional step 36 of roughening at least a section of the pipe 20 in which the heating device 19 will be fixed in place. In parallel, the heating wire 27 is wound onto the carrier 28 and the leads 25a, 25b are connected (step 37). Then (step 38), the carrier 28 is slid onto the cylindrical section 21 of the pipe 20. Because this section 21 is straight and the pipe 20 is relatively short, this step 38 is relatively easy to perform. The features for connecting the outlet conduit 13 to the connector 14 (in this case, the groove 24) are all concave, so that the carrier 28 can have an inner diameter that corresponds to the outer diameter of the straight section 21 of the pipe 20 within a selected tolerance range.

[0147] The assembly is then placed (step 39) in a mold (not shown) that encloses at least the section of outlet conduit 13 corresponding to heating device 19. Carrier 28 positions heating wire 27. Injection molding 40 secures heating device 19 to conduit 20. The assembly is then removed from the mold (step 41), and after the injection-molded material cools, thermal fuse 26 is connected (step 42). Finally, cap 33 is attached (step 43).

[0148] The leads 25a, 25b may be provided with one or more connectors at their free ends for insertion into sockets of the power control device 18 during installation of the outlet conduit 13 in the dispenser housing 2.

[0149] Since the heating device 19 is strongly and securely attached to the pipe 20, the outlet conduit can be handled and stored relatively easily before being installed in the dispenser 1. The injection moulded material and the cover 33 shield the sensitive components and connections relatively well.

[0150] The present invention is not limited to the above-described embodiments, and may be varied within the scope of the appended claims. For example, although an example of a resistive heating device 19 has been used, in another embodiment, the heating device 19 may be an induction heating device. In that case, one or more coil wires forming an induction coil replace the heating wire 27.

[0151] In an alternative embodiment using resistive heating device 19, heating wire 27 is omitted. Instead, mass 31 of injection-molded material itself comprises a conductive material or compound. A carrier 28, or an alternative separator having a higher resistivity than the injection-molded material, separates the conductive material or compound from tubing 20 to prevent short circuits. The terminal at the end of at least one of leads 25a, 25b is embedded in the conductive material. The end of the other lead 25a, 25b can be connected to a thermal fuse 26, which is electrically connected to the conductive material or compound on the opposite side of the injection-molded conductive material extension from the terminal at the end of the other lead 25a, 25b. Alternatively, thermal fuse 26 can be omitted, with the ends of both leads 25a, 25b embedded in the conductive material or compound on opposite sides of the conductive material extension. In that case, the conductive material or compound can have a resistivity that increases nonlinearly with temperature, allowing thermal fuse 26 to be omitted. One example of a suitable material is PTC rubber, a compound made of polydimethylsiloxane loaded with carbon nanoparticles.

[0152] In yet another alternative example, a heating foil is used instead of the heating wire 27 .

Claims

1. A conduit for a liquid distributor (1), comprising: a pipe (20) for carrying a liquid; and a heating device (19) for heating at least a section of the pipeline (20); The heating device comprises a component (31) for fixing the heating device (19) to the pipe (20), characterized in that: The component (31) is a component that is injection molded on the pipe (20) along at least a length of the pipe (20).

2. The catheter according to claim 1, characterized in that An injection molded part (31) is arranged around the pipe (20).

3. The catheter according to claim 1 or 2, characterized in that The heating device (19) is an electric heating device (19).

4. A catheter according to any one of the preceding claims, characterized in that The heating device (19) includes a resistance heating element (27).

5. The catheter according to claim 4, characterized in that The resistive heating element is included in a component (31) that is injection molded onto the pipe (20).

6. The catheter according to claim 4 or 5, characterized in that The resistive heating element (27) comprises a wound heating wire.

7. The catheter according to claim 6, characterized in that: further comprising a carrier (28); wherein the heating wire (27) is wound around the carrier (28), and The carrier (28) is arranged between the pipe (20) and the injection-molded part (31).

8. A catheter according to any one of the preceding claims, characterized in that The injection molded part (31) comprises at least one feature arranged to cooperate with a feature (32a, 32b) of a separate component (33) of the heating device (19) to lock the separate component (33) to the injection molded part (31).

9. A catheter according to any one of the preceding claims, characterized in that The heating device (19) further includes a component (26) disposed in thermally conductive relationship with at least one of the injection molded part (31) and the conduit (20).

10. The catheter according to claims 8 and 9, characterized in that A component (26) arranged in thermally conductive relationship with at least one of the injection molded part (31) and the conduit (20) is clamped thereto by a separate component (33) that locks to the injection molded part (31).

11. A method of manufacturing a conduit for a liquid distributor (1), such as a conduit according to any one of the preceding claims, the method comprising: ● providing a conduit (20) for carrying the liquid; as well as • securing a heating device (19) to the pipe (20) for heating at least a section of the pipe (20); Its characteristics are: The step of fixing the heating device (19) comprises placing at least the pipe (20) in a mould and injection moulding a part (31) of the heating device (19) over at least a length of the pipe (20).

12. A dispenser for dispensing liquid, characterized in that: Comprising a catheter (13) according to any one of claims 1 to 10.

13. The dispenser according to claim 12, characterized in that The conduit (13) forms the dispensing outlet (5).

14. The dispenser according to claim 12 or 13, characterized in that Also included is a connector (14) for connecting the conduit (13) to one of the manifold (8) and the further conduit (15).

15. Use of a catheter (13) according to any one of claims 1 to 10, characterized in that Used to combat retrograde contamination in a liquid distributor (1).

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