In particular, this invention relates to a portable, Insulated Flask Unit which is suitable for mantaining liquids at required temperatures for extended periods of time.

BACKGROUND ART : Portable Insulated Flask Units, particularly in the form of Vacuum Flasks, Water Jugs and WatersBottles are well known in the prior art. Each product has plus points, but ipso facto, satisfies a specific need; no one product can have every possible characteristic and thus fulfill every requirement under all possible circumstances. Conventional Vacuum Flasks are fragile, Water Jugs are bulky and Water Bottles are difficult to clean from inside. Existing products are so designed that damage to any component is either non-repairable, or, if repairable, then the component replacement cost is, by ratio, a very substantial chunk of the entire unit cost.

DISCLOSURE OF INVENTION : This invention seeks to provide a portable Insulated Flask Unit which is neither fragile nor bulky and is easy to clean. The unit is formed from components which are seperable and replace- able at low cost. One special feature is that the liquid containment Flask is a distinct, seperable entity. This allows Flask seperation, its filling, its chilling and its refitting. Another special feature is that within the same overall product concept, different insulation, chilling and level of liquid contained sighting systems are possible. This allows improved product compatibility with actual use circumstances.

My prior application, 885/MUM/2000 is for a more basic product.

According to this invention, there is provided a portable Insulated Flask Unit comprising : A liquid containment Flask, capable of receiving and storing liquids securably, the Flask being capable of becoming enclosed within a similar shaped but larger insulating or chilling Receptacle, and when so enclosed, the Flask becoming, within the Receptacle, locationally secure but non fixed, and, also or not, via their shape, the two to interlock loosely, the Receptacle being an operationally reversible assembled combination of three different insulatory or chilling rigid Polymer shells, the main Body shell always twin walled, the walls interspaced or upon each other, and when interspaced, to be with additional interwall spaced insulation, solid or gaseous, or in the alternate, a freezable or chillable liquid , and the other two shells, when also twin walled, to follow so, the Flask and shells to be possibly so formed that level of liquid in Flask can be optically sighted even when the filled Flask is within the Receptacle, there to be an optionally usuable Cylinder around Flask when Flask be within the Receptacle, operationally, the filled Flask containing cold or hot liquid to rest within the assembled Receptacle, and then, the Receptacle's inmost sides to be mostly in a concentrically apart position from Flask side wall or Cylinder, and thus, the Receptacle to define an additional insulating Air Space which is within the area internally circumscribed by it but around the enclosed Flask.

According to the preferred embodiment of this invention, the liquid containment Flask is made from food grade Polymer, Metal, Glass or Ceramic, only of one or in combination, the Flask being clear or opaque, intrinsically reflective or externally reflective, optionally, the Flask exterior to be coated wholly or partly with another surface layable material to improve its utility, the Flask, when opaque, and material used permitting, to be without or with a sighting window, the Flask to be with a straight line neck or with a step wise

neck, the neck having an opening, this opening being securably closable with a releasable Closure Piece, this Closure Piece to be without or with an additional liquid drinker, and or not, the Flask being so formed that it can loosely interlock with its operationally locational surrounding form.

Conveniently, the liquid containment Flask can, after being filled, be chilled, and then be placed within and so be enclosed by a similar shaped but larger Receptacle, this Receptacle being an operationally reversible assembled combination of three different insulatory or chillable Polymer shells, a Body shell, an Intermediate shell and a Top shell, each shell having a form which is larger than its corresponding area part of the Flask, each of the three shells mating releasably with its specific partner shell, at a specified place, for Receptacle assembly and usage, firstly, the Body shell's inner part's base's inner face giving resting support to the base of the upright, filled, chilled Flask, and by doing so, the shell siting within itself, the Body of the Flask, then, the Intermediate shell to mountingly couple with the Body shell via their open mouths, and thereby, this Intermediate shell to cover a subsequent, non-enclosed part of the Flask, and simultaneously, to give upward egress passage to the neck opening and neck part of the Flask through an integral vacuity in its base, then, the Top shell to come mountingly over Intermediate shell and thus cover the balance unenclosed part of the Flask, all shells, by their design, being denied excessive mutual rotational closure movement during coupling so that deformation of Flask or shell is avoided, and optionally, the shells to be so formed that even when and while filled Flask is within the Receptacle, the level of liquid in the Flask can be optically sighted.

Expediently, the Body shell is of two parts, an outer and an inner, one within the other, both securable to each other, fixedly or removably, the sides of both to be smooth or planed , both parts to be clear or partially clear or not clear,

intrinsically reflective by the incorporation of suitable material during shell production process or inner and outer side reflective by the application of a reflective film, metal, resin or polymer, optionally, both parts, when reflective or opaque, to have incorporated, vertical, back-to-back sighting windows, one or both parts to have formed threads or grooves for non permanent coupling with the other shells, and, when the two parts comprising the shell are securably spaced apart, the created space between the two parts to be filled with another insulating material, solid or gaseous, or, with a freezable or chillable liqud, this liquid in cavity system resulting in Body shell precilling procedure, and further, the inner part's base's inner face and or inner side to be so formed that it or they interlock loosely or not with the Flask form.

Purposely, the Intermediate shell can be of one part or of two, if two, then one within the other, both securable to each other, fixedly or removably, the part or parts to be clear or partially clear or not clear, intrinsically reflect- ive or any or all side reflective, the part or parts to have formed threads or grooves for non permanent coupling with the other two shells, and, when shell be of two parts, secur- ably spaced apart, then, the created space between the two parts to be filled with another insulating material, solid or gaseous, or, with a freezable or chillable liquid, this liquid in cavity system resulting in entire shell prechilling procedure, optionally, both parts, when reflective or opaque, to have incorporated, vertical, back-to-back sighting windows, and further, the base of this shell to possess integrally, a centrally located vacuity, this vacuity's peripheral wall to have on itself, a flexible ring shaped Washer of specific form, wherein operationally, this Washer rests in a releasably sealing firm fashion on Flask neck and so, exerts sealing, locational holding and downward pressure on such neck, and operationally also, such base vacuity allowing egress passage to neck opening of Flask and

part of Flask neck during coupling with Body shell, and, the passage of such parts through such vacuity allowing peaceful operational activity of and on the neck opening, even while and though Body shell and Intermediate shell are in operational configuration around the filled Flask.

Usefully, the Top shell can be of one part or of two, if two, then one within the other, both securable to each other, fixedly or removably, the part or parts to be intrinsically reflective or side reflective, the part or parts to have formed threads or grooves for non permanent coupling with the other shells, and, when the shell be of two parts securably spaced apart, then, if advantageous, the created space between the two parts to be filled with another insulating material, solid or gaseous, or, with a frezable or chillable liquid, this liquid in cavity system resulting in entire shell prechilling procedure, and further, the part or parts to be also capable of being used as a cup or cups.

Conveniently, to extend the stable temperature capability of the unit, there is a twin walled Polymer Cylinder, which, within its securably spaced apart walls, contains a freezable or chillable liquid, wherein, when Flask is within assembled Receptacle, this Cylinder, in its prechilled state, is nonpermanently interspaced between Flask wall and Body shell.

The three rigid Polymer shells, Body, Intermediate and Top, when assembled around the liquid filled Flask, form an insulating or chilling Receptacle, this Receptacle's inmost sides being mostly in a concentrically apart position from the Flask or from the additional Cylinder, and thus, such non- touching inmost sides allowing the formation of an additional, specific, restricted, annular, insulating Air Space around the Flask.

According to another embodiment of this invention, the liquid containment Flask, while being in situ within the assembled form of Body and Intermediate shells, allows, through the

accessible neck opening, peaceful filling and removal of liquid , and also, simultaneously, because of the sighting windows in the shells which, on Receptacle assembly, abut each other but become parallel to Flask window, it becomes possible to optically sight level of liquid in Flask while such liquid is being filled or removed.

BRIEF DESCRIPTION OF DRAWINGS : The following is a detailed description of the present invention with reference to the accompanying schematic drawings in which : Fig 1 is a vertical, outlined, situational, sectional view of the Flask when enclosed within the assembled Receptacle.

Fig 2 is a vertical, cross sectional view of the Device, wherein only the Body shell is twin walled.

Fig 3 is a vertical, cross sectional view of another possible configuration of the Device, wherein the Body shell and Intermediate shell are twin walled.

Fig 4 is also a vertical, cross sectional view of a further possible configuration of the Device, wherein all three shells are twin walled.

Fig 5 shows locational placement of the additional, pre- chillable twin walled Cylinder within the Device as per Fig 2 configuration.

Fig 6 is a perspective view of Body and Intermediate shells, showing location of sighting windows in them.

Fig 7 shows one possible system of forming back-to-back sighting windows in Body and Intermediate shells while shell has additional Insulation or liquid.

Fig 8 shows vertical outline representations of Flask shapes, neck shapes and sighting window location.

Fig 9 is an upturned, cross sectional view of the inter- locking of Flask base or Flask side wall with Body shell base or Body shell side wall.

Referring to the drawings, Fig's 1, 2,3,4 & 5 show the Device in accordance with the invention by the reference numeral 10.

Fig 1 shows a vertical, outline view of the liquid containment Flask 11, a vertical, outline view of the assembled and formed insulating or chilling Receptacle 12, and the created , enclosed, insulating Air Space 62.

Fig's 2,3,4 & 5 show amongst other things, the various configurations of the three shells, Body shell 13, Inter- mediate shell 14 and Top shell 15. Also shown are the Washer 16, the Closure Piece 17 for the neck opening of Flask, the twin walled Polymer Cylinder 18, the additional Insulation 19, in solid form, and in a similar location, the alternate, freezable or chillable liquid 20.

Fig 6 is a perspective view as per Device's Fig 3 configuration , showing consolidated sighting window 36 in Body shell 13 and consolidated sighting window 49 in Intermediate shell 14.

Fig 7 shows one way to form the consolidated sighting window 36 or 49 in Body shell 13 or Intermediate shell 14, while shell is with Insulation 19 or liquid 20.

Fig 8 shows the shape of the Flask 11, the Flask external area 23, and the Flask's vertical sighting window 24.

Fig 9 shows one possible way for Flask base 25 or side wall 26 to loosely interlock with Body shell's inner part's inner side 33 or inner part's base's inner face 38.

The Device and its components shall now be explained in greater detail : The components of the device are :

a) The liquid containment Flask, in the drawings, Ref No 11. b) The Body shell, in the drawings, Ref No 13. c) The Intermediate shell, in the drawings, Ref No 14. d) The Top shell, in the drawings, Ref No 15. e) The Washer, in the drawings, Ref No 16. f) The Closure Piece for Flask neck opening, in the drawings, Ref No 17. g) The Cylinder, in the drawings Ref No 18. h) The additional Insulation, in the drawings, Ref No 19. i) The alternate liquid, in the drawings, Ref No 20.

The Flask 11 is a distinct, seperable entity and will contain within itself, the required liquid. This Flask 11 is to be eventually enclosed within an assembled, formed, Receptacle 12. This Receptacle 12, is composed of three different Polymer shells, a Body shell 13, an Intermediate shell 14 and a Top shell 15. These shells can be similar but all have to be larger than the corresponding area parts of the Flask. These three shells are so formed that they couple with each other in a specific sequence, and, when the three shells are so coupled with each other, an insulating or chilling Receptacle 12, capable of enclosing within itself the Flask 11, is formed. Since the coupling system is non permanent and reversible, the Receptacle can be assembled and disassembled as required.

The liquid containment Flask 11, has a formed neck 21 which has an opening 22. This opening is securably closable with the releasable Closure Piece 17. The Flask's external area 23 may be covered wholly or partly with another surface layable material so as to improve its utility. The Flask, when opaque, and material used to make the Flask permitting, can be without or with a vertical sighting window 24. The Flask's base 25 or its side wall 26 may loosely interlock or not with Body shell's inner part's inner side or with Body shell's inner part's base's inner face. The Flask will be filled with the contained liquid 27, which, has not been shown.

The Body shell 13 has an outer part 28 and an inner part 29.29 is within 28 and 29 is securable to 28, fixedly or removably. The outer part 28 has two sides, an outer side 30 and an inner side 31. Similarly, the inner part 29 has an outer side 32 and an inner side 33. The two parts, 28 & 29 can be intrinsically reflective, and, or, the four sides, 30,31,32 & 33 can be surface reflective. The outer part 28 when reflective or opaque, can have an incorporated, vertical sighting window 34. The inner part 29 when reflective or opaque, can have an incorporated, vertical sighting window 35. These two parts 28 & 29, when with such windows 34 & 35, are so intersecured that 35 is directly behind 34, thus giving a Body shell consolidated, vertical sighting window 36, as shown in Fig's 6 & 7. When 28 is securably spaced apart from 29, a created space 37 is formed. This space 37, can be totally filled with another insulating material 19, this material 19 being solid or gaseous, or, with a freezable or chillable liquid 20 as shown in Fig 2. The Body shell, even while filled with 19 or 20 can have an incorporated sighting window 36 as shown in Fig 7. This shell's inner part's base's inner face 38 and or inner part's inner side 33 may be so formed that they interlock loosely or not with Flask base 25 or Flask side wall 26, as shown in Fig 9. The Body shell has a mouth 39, whereby non-permanent coupling with the other two shells is possible. This shell also has a Device holding system 40, which can be a handle, carry strap or carry cover.

The Intermediate shell 14 can be of one part or of two, if two, an outer 41 and an inner 42.42 is within 41 and 42 is securable to 41, fixedly or removably., The outer part 41 has two sides, an outer side 43 and an inner side 44.

Similarly, the inner part 42 has an outer side 45 and an inner side 46. The parts 41 & 42 can be intrinsically reflective and the sides 43,44,45 & 46 can be surface reflective. The outer part 41, when reflective or opaque, can have an incorporated, vertical sighting window 47. The inner part 42, when reflective or opaque, can have an

incorporated, vertical sighting window 48. These two parts 41 & 42, when with such windows 47 & 48, are so intersec- ured that 48 is directly behnd 47, thus giving an Inter- mediate shell consolidated sighting window 49 as shown in Fig's 6 & 7. When 41 is securably spaced apart from 42, a created space 50 is formed. This space 50 can be totally filled with another Insulating material 19, this material 19 being solid or gaseous, or, with a freezable or chillable liquid 20 as shown in Fig 3. The Intermediate shell, even while filled with 19 or 20, can have an incorporated sighting window 49 as shown in Fig 7.

This Intermediate shell 14 has within its base 51, a centrally located vacuity 52. This vacuity's depending peripheral wall has on itself, a flexible ring shaped Washer 16 of specific form. This base vacuity 52 allows through itself, upward egress passage to neck opening 22 and part of neck 21 when, Intermediate shell is being coupled with Body shell, provided of course, that the Body shell is then containing the Flask 11. When Body shell 13 contains Flask 11 and is coupled with Intermediate shell 14, the neck opening 22 and part of neck 21 pass upwardly through the base vacuity 52, and then, the Washer 16's inner side comes and rests in a releasably sealing firm fashion on the Flask neck 21, and, so exerts sealing, locational holding and downward pressure on such neck. Additionally, the passage of such opening 22 and neck 21 through such vacuity 52 allows Flask contained liquid 27 to be accessible even while Body shell 13 and Intermediate shell 14 are in operational configuration around Flask 11, since operational activity of Closure Piece 17 on the neck opening 22 is not hampered by situational location of Body shell 13 and Intermediate shell 14. The Intermediate shell 14 is engageable via its mouth 53 to Body shell 13 The Top shell 15, can be of one part or of two, if two, then an outer 54 and an inner 55.55 is within 54 and is securable to 54, fixedly or removably. The outer part 54

has two sides, an outer side 56 and an inner side 57.

Similarly, the inner part 55 has two sides, an outer side 58 and an inner side 59. The parts 54 & 55 can be intrinsically reflective and the sides 56,57,58 & 59 can be surface reflective. Since this shell is at the top, it can be used as a cup or cups. If this shell covers a reason- ably large part of the Flask, it can have sighting windows, additional Insulation or alternate liquid. This shell has a mouth 60, whereby it can be releasably coupled onto and with the other shells.

There is a Polymer Cylinder 18, twin walled, walls spaced securably apart, the created space 61 between the walls being filled with a freezable or chillable liquid 20, as shown in Fig 5. This Cylinder can be prechilled before using within Device.

The three shells, Body shell 13, Intermediate shell 14 and Top shell 15 when assembled around the liquid filled Flask 11, form an insulating or chilling Receptacle 12. This Receptacle's inmost sides are mostly in a concentrically apart position from the Flask or from the additional Cylinder, and thus, such non-touching inmost sides allow the formation of an additional, specific, restricted, annular, insulating Air Space 62 around the enclosed Flask.

Uniquely, the liquid containment Flask 11"while being in situ within the assembled insulating or chilling form of Body shell 13 amd Intermediate shell 14, allows, through the accessible neck opening 22, peaceful filling and removal of contained item 27, with, simultaneous optical sighting of the level of liquid being filled or removed. This is possible because of the vertical parallel alignment of the window 24 in Flask 11 with the window 36 in Body shell 13 and window 49 in Intermediate shell 14.

BEST MODE FOR CARRYING OUT THE INVENTION : The described Insulated Flask Unit is made, assembled and operated as follows : The liquid containment Flask 11 is made from food grade Polymer , Metal, Glass or Ceramic, only of one or in combination, by, the appropriate production process, material selection, shape etc being a function of its usage circumstances. The Flask can be clear, opaque, be made intrinsically reflective by incor- porating suitable material during the production process or externally reflective by the application of a reflective film, metal, resin or polymer on the Flask's external side's. The Flask's exterior can also be coated wholly or partly with another surface layable material to improve its utility. If the Flask is produced opaque or subsequently made opaque, and material used to form the Flask permitting, a vertically running sighting window 24 can be incorporated into the Flask.

The Flask has a formed neck 21 which can be made in a straight line or with a step, as required. This neck 21 has an opening 22, via which Flask contained item 27 can be poured in or out. The mouth, rim or brim of such neck opening 22 is formed with male threads or grooves for secure but releas- able mating with Closure Piece 17, which, for this purpose , has formed mutually matching female threads or grooves.

The Closure Piece 17 can be without or with an additional liquid drinker. The liquid containment Flask 11 can be produced in a specific shape, so as to allow the Flask's loose interlocking with its operationally locational surrounding form.

The three shells, Body shell 13, Intermediate shell 14 and Top shell 15 are made from rigid Polymer. Each shell is made larger than the corresponding area part that it will eventually enclose. The Body shell is always of two parts, an outer and an inner, but, the other two shells can be made in one part or two, this being a function of the shell's actual Flask coverage area, utility and overall product style

and purpose. When the shell is of two parts, one part is within the other, and both parts are securable to each other, fixedly or removably. All the shell inner and outer parts can be made with smooth or planed sides, all parts can be clear or not clear, be intrinsically reflective or side reflective.

Each shell is given formed threads or grooves at the place where it is to mate with another shell and shoulder stops where such mating threads and grooves end, so as to prevent any unintentional operational excessive rotational closure movement between any two mating shells.

When the two shells are opaque or reflective, vertical, back- to-back sighting windows can be incorporated into each part.

When the shell's inner and outer parts have such windows and are being intersecured, this securing is done in such a manner that the position of the sighting window in the outer part is directly in front of the position of the sighting window in the inner part, thus giving a consolidated shell sighting window, as shown in Fig 7.

When the shell is of two parts, and the parts are securably spaced apart, the created space between the two parts can be filled with an additional insulating material 19, this material 19 being solid or gaseous, or, in the alternate, this created space to be filled with a freezable or chillable liquid 20. The shell, while with Insulation 19 or Liquid 20, can have an incorporated sighting window, as shown in Fig 7. Also, even when shell is of two parts, securable to each other, but parts non spaced apart, one can have a product with part's caused or part's reflectiveness caused insulation, as shown in Fig 4.

If so required, the Body shell's inner part's base's inner face and or inner side can be so formed that they interlock loosely with Flask base or Flask side wall, as shown in Fig 9. This interlocking, which is done to eliminate Flask movement during operational activity of Closure Piece 17 on Flask neck opening 22, can also be effected by making

the Flask and Body shell inner part in a square, oblong or such non circular shape.

The Intermediate shell's base 51 is given an integral, centrally located vacuity 52. On this vacuity's peripheral wall, a flexible ring shaped Washer 16 is to be attached.

This Washer's inner side matches the outer profile of the Flask neck part place where it will operationally come to rest and on its outer side, the Washer's shape allows secure but non permanent attachment to the peripheral wall of the centrally located vacuity 52 of base 51.

The Cylinder 18 is made from rigid Polymer with walls spaced apart, and the created inter wall space 61, is filled with the freezable or chillable liquid 20., The assembled Receptacle can be in two styles : 1) Shells with insulation, Receptacle to insulate.

2) Shells with freezable or chillable liquid, Receptacle to chill or, to keep chilled.

When shells and Receptacle are in style 1, the procedure given below is followed; if shells and Receptacle are in style 2, the shells have to be prechilled before following this procedure.

To utilise the Device, the liquid containment Flask 11 is filled with the liquid to be contained in the Flask 27.

Once the Flask is filled with this liquid 27, the Flask neck opening 22 is to be securably closed with the releasable Closure Piece 17 by coupling the Closure Piece onto the neck opening. The filled, closed Flask 11 can now be chilled in a Refrigerator or by other means until the contents of the Flask are at the required temperature.

When the Flask and its contents reach the required temperature, the Device can be assembled. The filled, closed, chilled, Flask 11 is held by its neck in an upright position, and,

in such position, with its base 25 downwards, lowered gently into the Body shell 13 through the Body shell's open mouth 39 until the Flask base 25 comes to rest on the Body shell's inner part's base's inner face 38. During the Flask siting process, or by its eventual resting within the shell, the Flask's side wall 26 or the Flask's base 25, can via their shape, loosely interlock with Body shell's inner part's inner side 33 or Body shell's inner part's inner face 38.

Once the Flask is resting peacefully within Body shell 13, with the Flask's base and lower Body being enclosed by the shell, the Intermediate shell 14 with its open mouth 53 downwards and its base 51 upwards, is held over neck opening 22 of Flask 11. Then, the Intermediate shell is lowered so that Closure Piece 17, neck opening 22 and part of Flask neck 21 pass upwardly through the ring shaped Washer 16, which, is on the peripheral wall of base vacuity 52. Now, the mouth 53 of Intermediate shell 14 approaches the mouth 39 of Body shell 13 ; via the appropriately located formed threads or grooves on 53 and 39, the two can be secured to each other. When coupling between these two shells is completed, the flexible Washer 16, which has allowed egress passage through itself to Closure Piece 17, neck opening 22 and part of neck 21, comes and rests in a sealing firm fashion on Flask neck 21.

At this point, within the insulating or chilling shape formed by the coupling of Body shell 13 with Intermediate shell 14, filled, closed, chilled, Flask 11 is location- ally secure but non fixed. The Flask's locational stability arises firstly from the loose interlocking between the Flask's side walls and base with Body shell side wall and base and secondly from the top locational fixing given to the Flask by the encirclement of Flask neck 21 by the Washer 16.

Finally, the Top shell 15 with its mouth 60 downwards, is held over Closure Piece 17 and this shell is brought over

the Intermediate shell and onto the Body shell as shown in Fig 2, or, over and onto the Intermediate shell as shown in Fig's 3 & 4. Owing to the mutually mating formed threads or grooves on Top shell mouth and its resting place on either shell, the Top shell, through applied rotational closure movement, can be coupled with its partner shell. When such coupling is over, the insulating or chilling Receptacle, 12, which encloses the filled, chilled Flask 11 is ready for use.

INDUSTRIAL APPLICABILITY : The unit can be kept or carried, as required. The Flask contained item, 27, will retain its temperature for a long time since both Flask 11 and its contents 27 had been pre- chilled before becoming enclosed within the Receptacle. Also, if the shells are with freezable liquid 20 and prechilled, or, if prechilled Cylinder 18 has been used, the Unit's stable temperature capability is further extended.

For actual liquid drinking, Top shell 15 is decoupled from the shell to which it is secured and kept aside. the Device user now has access to Closure Piece 17 on Flask neck opening 22 ; when such Closure Piece 17 is also decoupled from such neck opening 22, Flask contained item is accessible.

If the Closure Piece 17 has an additional liquid drinker, then only such additional liquid drinker will be made opera- tional and then, it might not be necessary to decouple Closure Piece 17 from neck opening 22.

The Device can also be used for hot liquids. In such a scenario, the filling of the Flask will be with a hot liquid and there will be no chilling of Flask or Flask contained item. Instead, the Flask 11, immediately after being filled with the hot liquid, has its neck opening 22 closed with the Closure Piece 17. Then, the filled Flask is immediately put within the Body shell 13, so as to permit the further assembly steps required to complete the enclosure of Flask 11 within Receptacle 12.

Alternatively, one could first put the empty Flask 11 within the Body shell 13, couple the Intermediate shell 14 onto Body shell, and then, through the opened and accessible neck opening 22, pour in the hot liquid into the Flask 11, fill it, and then close the open neck opening with the Closure Piece 17. After this, the Top shell could be coupled with its designated partner shell to complete the Device.

If Flask and shells have sighting windows, then while placing the Flask within the shell, care is taken to site the Flask window directly behind Body shell window. Thus in a sectional drawing of such a situation, the sighting windows will be parallel to each other, but in actuality, the Body shell window will be directly in front of the Flask window.

Subsequently, when Top shell is mountingly coupled with Body shell, because of the precalculated correct window location in Top shell, such Top shell window, will, on completed coupling, come and resting abut the Body shell window, thus giving a vertical window formed from Body and Top shell windows.