WO2018057376A1

WO2018057376A1 - Method for mounting a window wash nozzle, and window wash nozzle

Info

Publication number: WO2018057376A1
Application number: PCT/US2017/051438
Authority: WO
Inventors: Alexander Limpert; Christopher Gessner
Original assignee: Illinois Tool Works Inc.
Priority date: 2016-09-20
Filing date: 2017-09-14
Publication date: 2018-03-29
Also published as: DE102016117673A1

Abstract

The invention relates to a method for mounting a window wash nozzle, in particular a window wash nozzle of a vehicle, comprising the steps of: - providing a housing (10) having a housing base (34) and a housing inner wall (32), where a central projection (36) is arranged on the housing base, - fitting a housing cover (22) onto the housing, where the housing cover has at least two decentralized projections (42, 44) on its inner face which faces the housing base in the state in which said housing cover is fitted onto the housing, - inserting at least one heating wire (38, 40) into the housing, where the at least one heating wire runs on the housing base to the side of the central projection substantially along a straight line, - rotating the housing cover on the housing about a predetermined rotation angle, where the decentralized projections of the housing cover carry along the at least one heating wire when said decentralized projections are rotated, and rotate about the central projection of the housing base, so that the at least one heating wire lies in an S shape on the housing base after rotation of the housing cover is complete. The invention also relates to a window wash nozzle.

Description

METHOD FOR MOUNTING A WINDOW WASH NOZZLE,

AND WINDOW WASH NOZZLE

[0001] The invention relates to a method for mounting a window wash nozzle, in particular a window wash nozzle of a vehicle, such as an automobile. The invention also relates to a window wash nozzle designed for carrying out the method.

[0002] Window wash nozzles are used, for example, for applying a cleaning liquid to a window of an automobile for cleaning purposes. Both window wash nozzles which discharge substantially punctiform liquid jets and window wash nozzles which discharge fan-shaped liquid jets, or liquid jets which oscillate in a fan-like manner fashion, are known. Such window wash nozzles are known for example from US 4 645 126 A or EP 2 144 702 B 1. Also known is the arrangement of multiple window wash nozzles in series to form a nozzle chain. Here, all of the window wash nozzles of a nozzle chain may be connected to a common liquid supply for cleaning liquid.

[0003] In winter, there is the risk of window wash nozzles freezing up. It is therefore known for the window wash nozzles to be heated. For this purpose, heating wires are laid into a housing of the window wash nozzle. For heating purposes, and electrical voltage is applied to the heating wire, such that an electrical current flows through the heating wire. Owing to the electrical resistance of the heating wire, the heating wire warms up, and thus the window wash nozzle is heated. The mounting of such window wash nozzles, in particular of the heating wire in the housing, is however cumbersome. The heating wire is inserted manually through an opening into the housing and, in the housing, is laid in a loop around a central liquid inlet, such that the heating wire is arranged in (circular) ring-shaped fashion in the housing. This manual mounting process is difficult and time-consuming. Automated mounting is not possible. The problems are exacerbated if multiple heating wires, or a feed heating wire section and a return heating wire section, have to be laid in.

[0004] Proceeding from the prior art discussed, it is the object of the invention to provide a method and a window wash nozzle of the type mentioned in the introduction, with which the mounting process is simplified, automated mounting is made possible, and the heating performance is optimized. [0005] The invention achieves the object by means of the independent claims 1 and 12. Advantageous refinements can be found in the dependent claims, in the description and in the figures.

[0006] For a method of the type mentioned in the introduction, the invention achieves the object by means of the steps:

- providing a housing having a housing base and a housing inner wall,

where a central projection is arranged on the housing base,

- fitting a housing cover onto the housing, where the housing cover has at least two decentralized projections on its inner face which faces the housing base in the state in which said housing cover is fitted onto the housing,

- inserting at least one heating wire into the housing, where the at least one heating wire runs on the housing base to the side of the central projection substantially along a straight line,

- rotating the housing cover on the housing about a predetermined rotation angle, where the decentralized projections of the housing cover carry along the at least one heating wire when said decentralized projections are rotated, and rotate about the central projection of the housing base, so that the at least one heating wire lies in an S shape on the housing base after rotation of the housing cover is complete.

[0007] The invention furthermore achieves the object by means of a window wash nozzle, in particular window wash nozzle of a vehicle, designed to carry out the method as claimed in one of the preceding claims, comprising a housing with a housing base and a housing inner wall, where a central projection is arranged on the housing base, and comprising a housing cover which is fitted onto the housing and can rotate in relation to the housing, where the housing cover has at least two decentralized projections on its inner face which faces the housing base in the state in which said housing cover is fitted onto the housing, where at least one heating wire is inserted into the housing.

[0008] The housing and the housing cover of the window wash nozzle according to the invention may be composed of plastic, produced for example in a plastics injection molding process. The window wash nozzle may serve for spraying a cleaning liquid onto a window of an automobile. The window wash nozzle according to the invention, for the window wash nozzle used in the method according to the invention, comprises a nozzle element which is generally likewise arranged in or on the housing of the window wash nozzle. The nozzle element may be integrally connected to the housing, for example by likewise being produced in a plastics injection molding process. The nozzle element has at least one outlet opening via which cleaning liquid emerges during operation. It is both possible for a non-oscillating, substantially punctiform liquid jet to be discharged via the at least one outlet opening during operation, and for a fan-shaped liquid jet, in particular a liquid jet which oscillates in a fan-like manner, to be discharged via the at least one outlet opening during operation.

[0009] As already discussed, during operation, and electrical voltage is applied to the heating wire which is laid in the housing, whereupon an electrical current flows through the heating wire. Owing to the electrical resistance of the heating wire, this leads to the heating wire warming up, and thus to the window wash nozzle being heated. The heating wire may comprise a plastics insulator, in particular if it is arranged in regions of the window wash nozzle that are filled with liquid during the operation of the window wash nozzle. The housing of the window wash nozzle may have two liquid connectors, one of which serves as an inlet for a cleaning liquid and one of which serves as an outlet for the cleaning liquid. The window wash nozzle may be part of a window wash nozzle chain arrangement, in the case of which multiple window wash nozzles are arranged in series and are supplied via the same liquid supply. The at least one heating wire may be led through the housing through the liquid connectors. Then, the liquid connectors are correspondingly also heated during operation.

[0010] According to the invention, a central projection is arranged on the housing base of the housing. For the mounting process, the housing cover is fitted onto the housing. The housing cover has at least two decentralized projections on its inner face which faces the housing base, which projections project in the direction of the housing base, in particular may extend substantially as far as the housing base, in the state in which said housing cover is fitted onto the housing. In this fitted state, the housing cover is initially situated in a pre- mounted position. Preferably, after the fitting of the housing cover onto the housing, the at least one heating wire is inserted into the housing, in particular through at least one housing opening. In the inserted state, the heating wire lies in particular on the housing base and runs to the side of the central projection of the housing base substantially along a straight line. It is pointed out that it is basically also possible for the heating wire to be inserted into the housing before the fitting of the housing cover. The insertion is however preferably performed after the fitting of the housing cover. In particular, this mounting sequence is particularly suitable for automated mounting. After the housing cover has been fitted onto the housing in the pre-mounted position and the at least one heating wire has been inserted into the housing, the housing cover is rotated about a predetermined rotation angle, in particular into its fully mounted position. During the course of the rotation, the decentralized projections of the housing cover capture the at least one heating wire and carry the latter along during the rotation of said housing cover. Here, the at least one heating wire is laid around the central projection of the housing. The central projection arranged on the housing base thus serves as a fixing or anchoring point for the rotation of the at least one heating wire. The arrangement of the decentralized projections of the housing cover and the rotation angle are configured such that the at least one heating wire lies in an S shape on the housing base after the rotation of the housing cover is complete. The S shape may self-evidently form a symmetrical or asymmetrical S shape. It is also possible for the S shape to have one or more kink-like direction changes.

[0011] By means of the formation of the projections on the housing base and the housing cover, the invention permits fast and simple mounting. In particular, according to the invention, automated mounting is also made possible. At the same time, by means of the arrangement according to the invention of the decentralized projections and the selection of a suitable rotation angle, it is possible for the at least one heating wire to be arranged on the housing base such that the heating action is optimal. In particular, the heating wire can in this way be laid flexibly and in targeted fashion close to those regions of the window wash nozzle which require a particular level of heating power. The admission of liquid may take place to the side in relation to the heating wire.

[0012] The projections which are arranged, according to the invention, on the housing cover and on the housing base may be formed in the manner of pins or bolts. The central projection of the housing is arranged substantially centrally on the housing base. An arrangement exactly centrally or in the middle is not imperative. It is merely important that the heating wire is laid around the central projection during the course of the rotation of the housing cover and the carrying-along by the projections of the housing cover. The housing base may for example be circular. The housing inner wall may correspondingly be of circular cylindrical form, for example. The housing cover or the inner side thereof may also be circular. The projections of the housing cover are arranged eccentrically in relation to the housing cover or the inner side thereof. They may be arranged substantially on an imaginary circle, for example so as to be rotationally offset with respect to one another by a rotation angle of approximately 190°. The projections may be connected integrally to the housing base or to the housing cover.

[0013] The at least one heating wire may be inserted into the housing through a first housing opening and routed out of the housing through a second housing opening. This configuration is expedient in particular in the case of a window wash nozzle chain with multiple window wash nozzles according to the invention connected in series, because the at least one heating wire can then be led through all of the window wash nozzles. The decentralized projections of the housing cover may be arranged on opposite sides of the at least one heating wire after the housing cover is fitted and before the housing cover is rotated. In this way, the carrying-along of the at least one heating wire during the course of rotation is realized in a particularly simple manner, such that said heating wire is arranged in an S shape after the rotation.

[0014] In a further refinement, the decentralized projections of the housing cover may be at a distance of less than twice the thickness of the at least one heating wire from the housing inner wall after the rotation of the housing cover is complete. The projections of the housing cover thus arranged in the vicinity of the inner wall, which is for example of circular cylindrical form, of the housing. In the fully mounted state, the heating wire is looped around the projections of the housing cover and, here, comes to bear against the outer side of the decentralized projections. Therefore, an arrangement of the decentralized projections in the vicinity of the housing inner wall has the effect that the at least one housing wire likewise bears against the housing inner wall and thus ensures optimum heating of the outer surfaces of the window wash nozzle, for example of a nozzle element. The abovementioned distance may furthermore preferably be less than 1.5 times the thickness of the at least one heating wire. It is furthermore preferably possible for the spacing to substantially correspond to the thickness of the at least one heating wire. Then, the heating wire is held particularly securely with a small amount of play between the decentralized projections and the housing inner wall when rotation of the housing cover is complete.

[0015] It may furthermore be provided that the at least one heating wire, in sections, lies closely adjacent to a nozzle element of the window wash nozzle after the rotation of the housing cover is complete. In this way, optimum heating of the nozzle element is realized. Furthermore, the at least one heating wire may, in sections, lie closely adjacent to a diaphragm element of the window wash nozzle after the rotation of the housing cover is complete. Such diaphragm elements of window wash nozzles are known per se and serve as a non-return element and also for guiding the cleaning liquid. Like the nozzle elements, they are generally situated at an outer surface of the window wash nozzle and therefore have a particular heating requirement.

[0016] In a particularly practical refinement, the housing cover may be rotatably latched to the housing during the course of fitting said housing cover onto the housing. For example, grooves may be provided on the inner side of the housing, which grooves enter into latching engagement with corresponding grooves of the housing cover. In this way, the housing cover is then rotatable particularly easily despite the latching with respect to the housing.

[0017] The completion of the rotation of the housing cover may be indicated by an indicator. For example, a projection may be formed on the housing cover, which projection engages into a corresponding recess of the housing after completion of the rotation, when the housing cover is thus situated in the fully mounted position. Said engagement can be optically checked, for example automatically by means of an optical sensor such as a camera. It is also possible for the pre-mounted position of the housing cover on the housing to likewise be indicated by means of an indicator. For example, a projection formed on the housing cover may engage into a further corresponding recess of the housing. This engagement, too, can be optically checked, for example automatically by means of an optical sensor such as a camera. The recesses of the housing which indicate the pre-mounted position and the fully mounted position may for example be offset with respect to one another by a rotation angle of approximately 190°. A kinematic reversal would self-evidently also be conceivable, in the case of which two projections are arranged on the housing, which projections engage into a corresponding recess of the housing cover. [0018] In a further refinement, the central projection of the housing and/or the at least two decentralized projections of the housing cover may have a tapered shape. In cross section, the projections then correspondingly have a central constriction. By means of said tapered shape, the carrying-along of the heating wire, and the looping-around of the heating wire during the course of the rotation of the housing cover, are ensured in a particularly reliable manner. In particular, the heating wire is prevented from slipping off the projections.

[0019] The housing cover may be welded to the housing after the rotation is complete. In this way, the window wash nozzle is optimally sealed for operation. As a welding process, use may for example be made of a plastics welding process.

[0020] In a further refinement, the method according to the invention may be carried out in an automated manner, in particular a fully automated manner. For this purpose, aim mounting apparatus, for example an automatic mounting machine or mounting robot, may be provided, which fits the housing cover onto the housing and subsequently rotates the housing cover by the defined rotation angle. Any subsequent welding of the housing cover to the housing may also be carried out by means of said mounting apparatus. The same applies to the insertion of the at least one heating wire into the housing. The economy of the method according to the invention is further increased by means of automated mounting.

[0021] The window wash nozzle according to the invention may be part of a window wash nozzle chain comprising a multiplicity of window wash nozzles according to the invention. The at least one heating wire may then run through all of the window wash nozzles.

[0022] An exemplary embodiment of the invention will be discussed in more detail below on the basis of figures. In the figures, in each case schematically:

Fig. 1 figure 1 shows a window wash nozzle according to the invention in a perspective view,

Fig. 2 shows the window wash nozzle from Fig. 1 without a housing cover in a perspective view, Fig. 3 shows a sectional view through the window wash nozzle from Fig. 1,

Fig. 4 shows the window wash nozzle from Fig. 1 with a partially cut-away housing cover in a perspective view,

Fig. 5 shows the illustration from Fig. 4 after the rotation of the housing

cover, in a view from above,

Fig. 6 shows the illustration from Fig. 5 in a perspective view,

Fig. 7 shows a sectional view through the illustration of Fig. 6, and

Fig. 8 shows the housing cover of the illustration from Fig. 7 in a

perspective view.

[0023] Unless stated otherwise, the same reference designations denote identical objects in the figures.

[0024] The window wash nozzle shown in Fig. 1 has a housing 10 with a first liquid connector 12 and a second liquid connector 14. The liquid connectors 12, 14

simultaneously form housing openings of the housing 10. At the reference designation 16, it is possible to see a nozzle element which is integrally formed on the housing and which has an outlet opening 18 through which, during operation, a cleaning liquid fed via the liquid connector 12 is discharged for example onto a window of an automobile. On that side of the housing 10 which is situated opposite the nozzle element 16 there is situated a diaphragm 20 which serves as a non-return element and for guiding the liquid. This is known per se. For example, in each case one hose which conducts the cleaning liquid may be fitted onto the liquid connectors 12 and 14. In Fig. 1, a housing cover 22 has been fitted onto the housing 10. The housing cover 22 has an engagement section 24 which can be engaged into by means of a tool, in particular for the purposes of rotating the housing cover 22. On its outer side, the housing cover 22 has grooves which enter into latching engagement with grooves 26, visible in Fig. 2, on the inner side of the housing 10. In this way, the housing cover 22 latches rotatably on the housing 10. In the pre-mounted state of the housing cover 22 shown in Fig. 1, a projection 28 formed on the outer side of the housing cover 22 engages into a first corresponding recess 30 of the housing 10. In this way, the pre-mounted position of the housing cover 22 is indicated in such a way that it can be optically checked.

[0025] Fig. 2 illustrates the window wash nozzle from Fig. 1 without a mounted housing cover 22. The housing 10 has a housing wall 32, which in the illustrated example is of circular cylindrical form, and a circular housing base 34. Centrally on the housing base 34 there is arranged a central projection 36, in the present case a bolt-like projection 36. It can also be seen in Fig. 2 that to heating wires 38, 40 are led into the housing 10 through the liquid connectors 12 and 14. The insertion of the heating wires 38, 40 is preferably performed after the fitting of the housing cover 22 onto the housing 10. In the present example, the heating wires 38, 40 may be sections of the same heating wire, specifically a section originating from an electrical voltage source and a section leading back to the electrical voltage source. Furthermore, the window wash nozzle that is shown may be part of a window nozzle chain arrangement in the case of which multiple such window wash nozzles are arranged in series. The heating wires 38, 40 may then provide a supply to all of the window wash nozzles of the nozzle chain. The same also applies to the liquid supply via the liquid connectors 12, 14.

[0026] It can be seen in Fig. 2 that the heating wires 38, 40 run to the side of the central projection 36 and along a straight line through the housing 10. Fig. 3 illustrates the window wash nozzle with fitted housing cover 22 and inserted heating wires 38, 40. As can be seen in the sectional view of Fig. 3, the housing cover 22 has two decentralized projections 42, 44 on its inner side facing toward the housing base 34. As can likewise be seen in Fig. 3, the decentralized projections 42, 44 extend substantially as far as the housing base 34 and each have a tapered shape. The decentralized projections 42, 44 are situated on opposite sides of the heating wires 38, 40 when the housing cover 22 has been fitted onto the housing 10 and is situated in its pre-mounted position and before the housing cover 22 has been rotated into its fully mounted position. Here, the decentralized projections 42, 44 are arranged on an imaginary circle so as to be offset with respect to one another by approximately 190°.

[0027] In Figs. 4 to 6, for illustrative purposes, the housing cover 22 has been partially cut away, such that only the decentralized projections 42, 44 are partially illustrated. Fig. 4 shows the starting point before the rotation of the housing cover 22 into its fully mounted position. If the housing cover 22 is then rotated with its grooves 46, visible for example in Fig. 3, into the grooves 26 of the housing 10, clockwise in the view of Fig. 4, then the decentralized projections 42, 44 firstly, to contact with the heating wires 38, 40 and carry these along during the course of the further rotation of the housing cover 22, wherein the heating wires 38, 40 are looped around the central projection 36 of the housing 10 until the position shown in Figs. 5 to 8 is reached. In Figs. 5 to 8, the heating wires 38, 40 are furthermore arranged one on top of the other. As can be clearly seen in particular in Fig. 5, the heating wires 38, 40 are, in this fully mounted state, arranged along an S shape on the housing base 34. The housing cover 22 may be rotated for example through approximately 190° proceeding from Fig. 4 until the fully mounted position shown in Fig. 5 is reached. Here, the projection 28 of the housing cover enters into engagement with a second recess 31 of the housing 10, and thus indicates the fully mounted position in a manner which can be optically checked.

[0028] It can likewise be clearly seen in Fig. 5 that the decentralized projections 42, 44 are at a distance from the housing inner wall 32, which distance substantially corresponds to the thickness of the heating wires 38, 40. In this way, the heating wires 38, 40 are held between the projections 42 and 44 and the housing inner wall 32 with a small amount of play. It can also be seen in Fig. 5 that, after the rotation is complete, the decentralized projections 42, 44 lie closely adjacent to the nozzle element 16 at one side and to the diaphragm 20 at the other side. Correspondingly, the heating wires 38, 40 are also arranged close to said components, which require particular heating power. In the illustration in Fig. 8, in which, for illustrative purposes, only the housing cover 22 with the heating wires 38, 40 is illustrated, it can be seen how the decentralized projections 42, 44, with their tapered shape, hold the heating wires 38, 40.

[0029] After the rotation of the housing cover 22 in the manner discussed, said housing cover may be welded to the housing 10 for the purposes of optimum sealing, for example in a plastics welding process. Both the housing and the housing cover may be composed of a plastic, produced for example in each case in a plastics injection molding process.

[0030] Since the heating wires 38, 40 are furthermore arranged in the liquid-conducting regions of the window wash nozzle, they are preferably equipped with a plastics insulator. [0031] According to the invention, the above-discussed mounting of the window wash nozzle, including the fitting of the housing cover 22, the insertion of the heating wires 38, 40, the rotation of the housing cover 22 and the welding, may be performed in automated fashion, in particular by means of a suitable mounting apparatus such as an automated mounting machine or mounting robot.

List of reference designations

10 Housing

12 Liquid connector

14 Liquid connector

16 Nozzle element

18 Outlet opening

20 Diaphragm

22 Housing cover

24 Engagement section

26 Grooves

28 Projection

30 Recess

31 Recess

32 Housing inner wall

34 Housing base

36 Central projection

38 Heating wire

40 Heating wire

42 Decentralized projection

44 Decentralized projection

46 Grooves

Claims

1. A method for mounting a window wash nozzle, in particular a window wash nozzle of a vehicle, comprising the steps of:

providing a housing (10) having a housing base (34) and a housing inner wall (32), where a central projection (36) is arranged on the housing base (34), fitting a housing cover (22) onto the housing (10), where the housing cover (22) has at least two decentralized projections (42, 44) on its inner face which faces the housing base (34) in the state in which said housing cover is fitted onto the housing (10),

inserting at least one heating wire (38, 40) into the housing (10), where the at least one heating wire (38, 40) runs on the housing base (34) to the side of the central projection (36) substantially along a straight line,

rotating the housing cover (22) on the housing (10) about a predetermined rotation angle, where the decentralized projections (42, 44) of the housing cover (22) carry along the at least one heating wire (38, 40) when said decentralized projections are rotated, and rotate about the central projection (36) of the housing base (34), so that the at least one heating wire (38, 40) lies in an S shape on the housing base (34) after rotation of the housing cover (22) is complete.

2. The method as claimed in claim 1, wherein the at least one heating wire (38, 40) is inserted into the housing (10) through a first housing opening and is routed out of the housing (10) through a second housing opening.

3. The method as claimed in either of claims 1 and 2, wherein the decentralized projections (42, 44) of the housing cover (22) are arranged on opposite sides of the at least one heating wire (38, 40) after the housing cover (22) is fitted onto the housing (10) and before said housing cover is rotated.

4. The method as claimed in one of the preceding claims, wherein the decentralized projections (42, 44) of the housing cover (22) are at a distance of less than twice the thickness of the at least one heating wire (38, 40) from the housing inner wall (32) after rotation of the housing cover (22) is complete.

5. The method as claimed in one of the preceding claims, wherein the at least one heating wire (38, 40), in sections, lies closely adjacent to a nozzle element (16) of the window wash nozzle after rotation of the housing cover (22) is complete.

6. The method as claimed in one of the preceding claims, wherein the at least one heating wire (38, 40), in sections, lies closely adjacent to a diaphragm element of the window wash nozzle after rotation of the housing cover (22) is complete.

7. The method as claimed in one of the preceding claims, wherein the housing cover is rotatably latched to the housing during the course of fitting said housing cover onto the housing.

8. The method as claimed in one of the preceding claims, wherein completion of rotation of the housing cover (22) is indicated by an indicator.

9. The method as claimed in one of the preceding claims, wherein the central projection (36) of the housing (10) and/or the at least two decentralized projections (42, 44) of the housing cover (22) have a tapered shape.

10. The method as claimed in one of the preceding claims, wherein the housing cover (22) is welded to the housing (10) after rotation is complete.

11. The method as claimed in one of the preceding claims, wherein it is carried out in an automated manner.

12. A window wash nozzle, in particular window wash nozzle of a vehicle, designed to carry out the method as claimed in one of the preceding claims, comprising a housing (10) with a housing base (34) and a housing inner wall (32), where a central projection (36) is arranged on the housing base (34), and comprising a housing cover (22) which is fitted onto the housing (10) and can rotate in relation to the housing (10), where the housing cover (22) has at least two decentralized projections (42, 44) on its inner face which faces the housing base (34) in the state in which said housing cover is fitted onto the housing (10), where at least one heating wire (38, 40) is inserted into the housing (10).

13. A window wash nozzle chain, comprising a plurality of window wash nozzles as claimed in claim 12, where the at least one heating wire (38, 40) runs through all of the window wash nozzles.

14. A method of engaging a window wash nozzle to at least one heating wire, comprising the steps of:

providing a housing (10) having a housing base (34) and a housing inner wall (32) extending from the housing base to define an internal housing space, where a central projection (36) projects from the housing base (34) into the housing space,

fitting a housing cover (22) onto the housing (10), where the housing cover (22) has at least first and second decentralized projections (42, 44) on its inner face and that extend toward the housing base (34) in a state in which said housing cover is fitted onto the housing (10),

inserting at least one heating wire (38, 40) into the housing (10), where the at least one heating wire (38, 40) runs through the housing space to a side of the central projection (36) substantially along a straight line,

rotating the housing cover (22) on the housing (10) about a predetermined rotation angle, where the first and second decentralized projections (42, 44) of the housing cover (22) contact and move the at least one heating wire (38, 40) when said first and second decentralized projections are rotated, and the first and second decentralized projections rotate about the central projection (36) of the housing base (34), so that the at least one heating wire (38, 40) traverses a circuitous path through the housing space that partially wraps about each of the first decentralized projection (42), the central projection (36) and the second decentralized projection (44) after rotation of the housing cover (22) is complete.