GB2459734A

GB2459734A - Corrugated flashing suitable for roof joints with offset adjoining columns

Info

Publication number: GB2459734A
Application number: GB0807930A
Authority: GB
Inventors: Neil Murray Rideout
Original assignee: Building Product Design Ltd
Current assignee: Building Product Design Ltd
Priority date: 2008-05-01
Filing date: 2008-05-01
Publication date: 2009-11-11
Anticipated expiration: 2028-05-01
Also published as: GB0807930D0; GB2459734B

Abstract

Flashing 10 formed from a substantially weatherproof material. The flashing 10 has a plurality of adjoining columns 12, and each column 12 comprises corrugations 11 which allow for the flashing 10 to be deformable. The corrugations 11 in a first column are off-set with respect to the corrugations 11 of an adjoining column. There is also provided a method of manufacturing the flashing 10. The flashing 10 is particularly suitable for use in weatherproofing roof structures around joints.

Description

IMPROVED MATERIALS FOR FLASHING

The present invention relates to flashing, and particularly, but not exclusively, to flashing for use in protecting roofjoints.

Flashing is typically used in the building trade to prevent weather damage, and specifically rain damage, to vulnerable areas of building structures. Commonly, flashing is formed from thin continuous pieces of material which are intended to be impervious to weather.

The flashing is typically placed around joints or angles in a structure, and acts to prevent to the passage of water from the exterior of the structure to the underlying materials which form the angles or joints. Typically, flashing may be used on roof joints for protecting them from the weather, although it may also be used on other areas of a building structure as required.

Flashing is typically formed from sheet metal or a water proofing membrane, such as bituminous fabric or plastic sheet material, depending on the climate and structural requirements. Lead has been and continues to be used for flashing due to its malleability and ease of application around the angles or joints to be protected. However, lead has known health and environmental problems and has therefore seen a decline in use.

Other alternatives, such as sheet metal, can be typically difficult to form into the desired shape to form a tight fit around the joint to be protected. This results in increased time being required to fit the flashing, thereby increasing labour costs.

Other alternatives such as sandwich or composite materials are typically more expensive and do not always have the required lasting deformation properties.

There is a considerable need to solve the problems associated with prior flashing as described herein.

The present invention seeks to provide flashing, and in particular, but not exclusively, flashing for roof structures which is malleable and easy to apply.

Additionally, the present invention seeks to provide flashing which is easier and typically cheaper to manufacture in comparison to prior attempts as described herein.

The present invention also seeks to provide a method of making the flashing.

According to a first aspect of the present invention there is provided flashing formed from a substantially weatherproof material, the flashing comprising a plurality of adjoining columns, each column comprising corrugations which allow the flashing to be deformable, whereby said corrugations in a first column are off-set with respect to corrugations of an adjoining column.

According to a second aspect of the present invention there is provided a method of manufacturing the flashing of the first aspect comprising the steps of: providing a substantially weatherproof material; and forming a plurality of adjoining columns in the substantially weatherproof material, each column comprising corrugations which allow the flashing to be deformable; whereby said corrugations in a first column are off-set with respect to corrugations of an adjoining column.

It has been found that having flashing formed with corrugated columns which are off-set with respect to corrugations of adjoining columns provides for cheap and simple to manufacture flashing. The off-set corrugated profile also provides for improved malleability of the flashing in comparison to prior flashing such as sheet metal. The off-set corrugated profile provides a larger number of lines and points which allow for bending of the flashing in different directions.

The improved malleability allows the flashing to be spread out and cold formed on site to form tight fit covering over vulnerable joints or angles, or to follow curves or other shapes as desired.

Additionally the arrangement of off-set corrugations provides flashing which may have improved strength whilst also being lighter than prior flashing.

Each column comprises a plurality of individual corrugations. The corrugations may be formed by a sequential series of peaks and troughs, thereby providing an undulating profile. These peaks and troughs may be formed along a longitudinal axis of each column. The columns therefore are corrugated in profile.

The plurality of peaks and troughs in each column may be formed identically with regard to their cross-section (i.e. all having the same amplitude and distance between neighbouring peaks or neighbouring troughs in the same column).

The amplitude of each peak and trough area may be in the range of 0.02 cm to 5 cm. Preferably the amplitude is in the range from 0.2 cm to 0.8 cm.

The depth of the corrugated flashing material preferably has a maximum depth in the range 0.01 cm to 10 cm. Preferably, a depth in the range 0.3 cm to 0.7 cm.

The distance between each neighbouring peak or trough in the same column is preferably no more than 5 cm. More preferably, the distance is no more than 2 cm. Most preferably, the distance is in the range 0.5 to 1.5 cm.

It is envisaged that each corrugated column has a width of less than 20 cm.

Preferably, the width of each column is less than 10 cm, More preferably, the width is in the range 1 cm to 5 cm.

The flashing may be formed from a substantially flat sheet of material which is worked to form a corrugated sheet having the adjoining corrugated columns.

It is envisaged that having flashing formed from a sheet of material may be preferred over forming the flashing from individual elements, as this advantageously would not require the use of additional fixing components which may otherwise add to the cost of manufacture, complexity, and weight of the flashing.

The sheet of material forming the flashing may have a width in the range 300mm to 900mm. More preferably, the sheet may have a width in the range 500mm to 700mm.

Most preferably, a width of 600mm.

Each corrugated column of the flashing is off-set with respect to a neighbouring adjoining column. It should be understood that the term off-set corrugated columns' refers to the feature that the corrugations in a first column are not in-line with the corrugations present in an adjoining column. For example, the peak areas of the first column may be in-line with the trough areas of the adjoining column. It is also envisaged that any suitable arrangement of off-set corrugated columns would be encompassed by this term, and is only limited by the requirement that the corrugations of adjoining columns are not in-line.

The corrugations may extend uniformly across the flashing forming a continuous wave form type material.

The corrugations preferably extend substantially across the whole surface of the flashing.

It will be understood that the corrugations may completely extend across the whole surface. Alternatively, the flashing may comprise portions which are not corrugated, such as edge portions which may provide an area suitable to allow for affixing the flashing to a structure. These non-corrugated portions may also be formed from non-deformable materials.

It will be understood that the term extending substantially across the whole surface refers to the corrugations extending across at least 90% of the whole surface.

It is envisaged that the flashing may have a degree of movement in order to contract and expand according to thermal stresses, especially when in an outdoor environment where it is exposed to variable climatic conditions. The limited movements of expansion or contraction prevent damage to the flashing due to temperature fluctuations.

As the flashing is corrugated, the area of material forming the flashing per unit area of flashing is higher than prior flashing such as flat lead sheets. This allows for increased malleability of the flashing, and therefore allows the user to easily form the flashing in to the desired shape around a structure.

The corrugated flashing may allow for covering and dressing of typically 25-30% greater surface area than compared to a flat sheet plan area due to the corrugations allowing the corrugated form to spread further than the comparable flat sheet.

The flashing may also comprise cavity trays. The cavity trays may be affixed to the flashing material, preferably at an edge of the flashing material, using any known method.

Cavity trays are preformed ready-shaped three-dimensional devices which fit to cavity walls in order to provide long term damp protection and to collect moisture from the wall cavity. Cavity trays are known in the field.

The substantially weatherproof material may be any suitable material capable of resisting typical weather conditions, and thereby protecting a structure surface to which said flashing is applied.

It is understood that the term substantially weatherproof material includes all materials which may be used for flashing, and would be resistant to degradation to the extent that the flashing would continue to function after exposure to typical weather conditions over a reasonable period of time, such as several years.

The substantially weatherproof material may be any material selected from, by way of example, aluminium or aluminium alloys, copper, zinc alloy, terne metal, or copper clad lead. Aluminium and aluminium alloy are particularly preferred.

The flashing may be formed from any combination of suitable substantially weatherproof materials.

The material may be selected from any appropriate grade, and the grade of material may be selected in order to provide malleability.

It is preferred that material formed from pure grades would be preferred to materials formed from alloys.

Suitable grades of material may be selected from aluminium 1050 (approximately 99.5% pure), aluminium 1080 (approximately 99.85% pure), or aluminium 1200 (approximately 99% pure). Aluminium 1050 is particularly preferred.

The thickness of the substantially weatherproof material may be in the range 0.10 mm to 5 mm. Preferably, the thickness of the material may be 0.15 mm.

The flashing may be affixed to a structure to be protected by any suitable means.

Suitable means may include, but are not limited to, use of adhesives, glues, resins, fasteners, clips, cables, wire, welding, soldering, taping, nails, or screws.

The flashing may preferably be secured to a structure by way of adhesive material. The flashing may comprise at least one adhesive area arranged on an outer surface of said sheet, and which is capable of affixing the flashing to a desired structure.

The flashing may have one adhesive area arranged on part or all of an outer surface. Alternatively, the flashing may have a plurality of adhesive areas arranged on an outer surface.

The adhesive material used for the adhesive areas may be any suitable material.

Suitable adhesive materials may be selected from, by way of example, cyanoacrylates, caseins, cements, rubber cements, resins, plastic cements, thermoplastic material, hot melt glues, acrylonitriles, or synthetic rubber adhesives.

Particularly preferred are synthetic rubber adhesives. More preferably, the adhesive material is butyl rubber adhesive.

The adhesive areas may have a removable protective film. The protective film may be removed immediately prior to application of the flashing to the structure.

The protective film acts to prevent dirt and other objects being adhered to the adhesive material during transit and storage of the application, and therefore prevents degradation of the adhesive material.

A suitable example of affixing the flashing to a structure would be the use of self-adhesive strips based on bitumen andior butyl rubber adhesive covered by removable protective film and arranged on a surface of the flashing.

The use of an adhesive material such as butyl backing (butyl rubber adhesive or butyl rubber based sheets) allows for adherence and adds mass to the flashing, which may be required as the flashing may be much lighter than traditional flashing made from lead (especially if formed from a lightweight material such as aluminium).

The flashing material may have an additional coating/lacquer to provide improved weather resistance properties. Suitable coatings include paint, anti-rust coatings, or other suitable protective coatings.

The flashing of the present invention may be formed using any appropriate method.

The material for forming the flashing may be obtained in an unprocessed flat form, such as soft aluminium coil sheets. The coils may be unwound, and the flat material may be passed through a set of corrugation rollers. The corrugation rollers may press the flat sheet to form repeating patterns of corrugations arranged in columns, where the columns are off-set.

The width of the coil used may be any width as described herein, but may typically be 600mm. It is envisaged that the width of material and therefore the width of the coil used would depend upon the size of the corrugation rollers and corrugation forming machine used.

The arrangement of the corrugation rollers may be such that the offset pattern of corrugations may be created across substantially all of the sheet material. The corrugation rollers may be selected to provide the desired pitch and profile height of the required corrugations and corrugation pattern.

The corrugations rollers may comprise a plurality of ridges and indentations capable of formingthe corrugations on the flat sheet material.

The method of forming the flashing may also comprise a step of applying any additional coating or lacquer to the substantially weatherproof material prior to passing the material through any rollers. It is envisaged that application of paints, coatings, or lacquers to the flashing material in a non-corrugated form would allow for a more uniform coatings than if applied to the material when corrugated.

The corrugated flashing may be laminated with an adhesive backing (such as butyl adhesive). The backing may be in the form of a sheet which may have a width substantially the same as the width of the corrugated material.

The corrugated flashing may be wound on to a final coil. The rewound final coil may either be for the full width of the corrugated flashing. Alternatively, the laminated corrugated flashing may be cut to various smaller widths and wound on to individual coils for each of the smaller widths.

The flashing may be supplied in the form of the coiled rolls of completed flashing. Alternatively, the flashing may be cut into specific shaped sections, and the -10-shaped sections may have cavity trays applied thereupon. The cavity trays may be affixed to the flashing by any suitable method.

The flashing may be arranged on an outer structure surface, such that it is at the interface between the structure surface and the external environment. Alternatively, the flashing may also be used in an internal area of the structure such that it is not directly exposed to the exterior environment.

It is envisaged that the flashing may particularly be used for ridge or edge coverings on the exterior of a structure, and in particular on a roof of a structure.

It is envisaged that the flashing of the present invention may be used for protecting vulnerable areas in any structure as appropriate. The flashing may in particular be used to protect areas of a roof where roof penetrating structures, such as chimneys, are present. Suitable uses of the flashing of the present invention therefore may include: Roof flashing -placed around cliscontinuities or objects which protrude from the roof of a building (such as pipes and chimneys, or the edges of other roofs) to deflect water away from seams or joints.

* Wall flashing -embedded in a wall to direct water that has penetrated the wall back outside at interruptions in the wall, such as windows and points of structural support.

* Sill flashing -concealed flashing that is typically placed under windowsills or door thresholds to prevent water from entering a wall at those points.

Base flashing -found at the base of walls, and usually incorporates through- -"-wall flashing with weep holes to permit the escape of water.

The above list is not intended to be exhaustive, and it is envisaged that the flashing of the present invention may be used in other areas of a structure as desired.

The flashing may be formed from one layer of the weatherproof material.

Alternatively, the flashing may be formed by using a number of layers of the deformable material in a stack-like arrangement.

The flashing may be commercially sold in roll form. The flashing may then be rolled on to the area to be protected, and subsequently cut to the desired size and affixed to the structure.

The flashing can be cold formed on to the structure. This is advantageous in comparison to prior flashing using, for example, lead which may require heating in-situ to form on to the structure.

Therefore, according to a third aspect of the present invention there is provided the use of the flashing of the first aspect for weatherproofing a structure.

Without wishing to be bound by theory, it is believed that the flashing of the present invention would provide good protection to a structure due to the use of off-set corrugated columns. The off-set corrugated columns in particular allow for the flashing to be easily deformable along both the longitudinal and latitudinal axis, and typically more so than for example flashing having corrugations which are aligned across the whole surface.

All of the features described herein may be combined with any of the above aspects, in any combination. -12-

For a better understanding of the invention, and to show how embodiments of the same may be carried into effect, reference will now be made, by way of example, to the accompanying diagrammatic drawings in which: Figure 1 shows a schematic perspective view of flashing of the present invention; Figure 2a shows a further schematic view of flashing of the present invention; Figure 2b shows an enlarged perspective view of a section of the flashing of Figure 2a; Figure 2c shows an enlarged section view of the flashing of Figure 2a; Figure 3 shows a schematic perspective view of flashing of the present invention inuseonaroof; Figure 4 shows a schematic perspective view of flashing with a cavity tray; Figure 5 shows a schematic perspective view of the flashing of Figure 4 in use on a roof; Figure 6 shows a schematic representation of a process for manufacturing the flashing of the present invention; and Figure 7 shows an enlarged schematic perspective view of a corrugation roller.

Referring to Figure 1, there is shown a schematic perspective view of a section of flashing 10 of the present invention. The flashing 10 is shown in a prior to use, and it is this form which would typically be sold to the end user. The flashing 10 shows a number of small corrugations 11 which cover the entirety of the flashing 10 surface.

Additionally, these corrugations 11 are arranged in a number of colunms 12 such that each column 12 has a number of peaks 14 and trougj-is 13 providing a corrugated -13 -waveform flashing 10.

Each column 12 is arranged and joined to neighbouring column 12. Each coiumn 12 is arranged such that the corrugations are off-set with regard to the neighbouring column 12, and therefore the peaks 14 and troughs 13 of one column 12 would not directly align with the peaks 14 and troughs 13 of the adjoined column 12.

The flashing 10 of Figure 1 is formed from aluminium which is lightweight, relatively cheap, and easy to process in to the corrugated form. The flashing of Figure 1 is formed from sheet aluminium such that the corrugated flashing 10 is formed from one sheet of the material. The advantage of forming the flashing 10 in this way is that no additional fixing means are required to fix each corrugated column 12 to the adjoining column 12 which saves on time and material costs for forming the flashing 10.

Referring to Figure 2a there is shown a further schematic perspective view of flashing material 20 of the present invention. The flashing 20 comprises a number of adjoining corrugated columns 21. The flashing material 20 has a width of 600 mm.

Referring to Figure 2b there is shown an enlarged perspective view of a section of the flashing material 20 of Figure 2a. The enlarged section shows in more detail the corrugations 28 which are arranged in columns 22. Additionally, the corrugations 28 can be seen to be off-set such that corrugations 28 in one colunm are not directly in-line with corrugations 28 in the adjoining column.

The flashing material 20 shows corrugations 28 having a width 22 of 25 mm. The corrugations 28 are formed such that the distance between the peaks 23 of neighbouring corrugations on the same column is 8 mm.

Referring to Figure 2c there is shown an enlarged section view of the flashing material 20 shown in Figures 2a and 2b. The section view shows that the corrugations 25 formed in the flashing material 20 provide a continual pattern of undulation with a sequence of peaks and troughs. The distance between peaks 26 in neighbouring corrugations is 8 mni, as also shown in Figure 2b. The section view also shows that the maximum depth 27 of the flashing material 20 is 4 mm.

Referring to Figure 3, there is shown a schematic perspective view of flashing 30 of the present invention in use on a building roof structure. The flashing 30 of Figure 3 is of the same type as described with reference to Figures 1 and 2. The flashing 30 is arranged such that it covers the area at the joint of the brick chimney column 31 and the tiled roof 32. In this way, the flashing 30 therefore weatherproofs this joint area, and prevents rainwater, snow, or ice from entering said joint.

The flashing 30 is deformable due to the presence of the off-set corrugation columns, and is arranged to follow the profile of the tiles 32 and chimney 31 to which it is affixed. The malleability of the flashing 30 due to the corrugations allows for a flush fit of the flashing 30 around the joint area, and therefore good protection of said joint with minimal gaps for rain to enter.

The flashing 30 has on the side affixed to the building structure an adhesive layer.

This adhesive layer comprises a layer of butyl adhesive which is exposed by the user by removal of a protective film, and is placed against the building structure.

The flashing 30 is cut to match the profile of the brick arrangement of the chimney breast. The flashing 30 forms a covering for the roof to wall abutment, and in -15-this embodiment cavity trays are attached to an edge of the flashing 30 and built into the brickwork, with the attached flashing 30 dressed over the joint. The cavity tray arrangement can be seen in Figures 4 arid 5.

Referring to Figure 4 there is shown a schematic perspective view of an embodiment 40 of flashing 41 affixed to a cavity tray 42. It is envisaged that the flashing 41 may be sold in this configuration 40 with the cavity trays 42 adapted to be embedded in to the brickwork to which the flashing 41 is applied. The attached flashing 41 is then dressed over the joint to be protected. For an embodiment for use on a chimney junction the flashing would not have cavity trays attached and a length of the flashing material would be used and stepped in to the brickwork jointing, or alternatively the length of flashing would be installed in to a raked chase groove.

Referring to Figure 5 there is shown a schematic perspective view of the flashing cavity tray embodiment 40 of Figure 4 in use on a roof. The cavity trays 50 are configured such that they are embedded in a second layer of bricks 54 which is placed on the outside of a first layer of bricks 51. The cavity trays 50 have a flap 55 which is arranged between the first 51 and second layer 54 of bricks to divert any water or moisture which is present between the brick layers 51 & 54 towards the exterior surface of the second layer of bricks 54. Only a portion of the bricks making up the second layer 54 are shown in order to show the cavity trays 50 which would otherwise be obscured in normal use.

The flashing material 52 is arranged below the level of the cavity trays 50 so any water or moisture diverted by the trays 50 exits the second layer of bricks 54 above the waterproof flashing material 52.

The flashing material 52 shown in Figure 5 covers the joint between the brick chimney and the roof tiles 53. This configuration is similar to that shown in Figure 4.

Referring to Figure 6 there is shown a schematic representation of a process 60 for manufacturing flashing of the present invention. The process 60 comprises a coil 61 of flat aluminium sheet 65 having a width of 600 mm. The coil 61 is unwound and the flat aluminium sheet 65 is fed between two corrugation rollers 62. The corrugation rollers 62 have a surface pattern which bends and forms the aluminium sheet 65 in to a corrugated sheet 67 having the desired corrugation pattern. The corrugation rollers 62 therefore form the offset corrugation pattern across the full width of the aluminium sheet 67.

The corrugated sheet 67 is then laminated on one side with a butyl adhesive backing sheet 68. The butyl adhesive backing sheet 68 is arranged on a roller 63. The roller 63 is unwound and the backing sheet 68 passes between the corrugated aluminium sheet 67 and a pressing roller 66 which press the backing sheet 68 and corrugated aluminium sheet 67 together. The corrugated aluminium sheet 67 is therefore laminated across its entire width. The resulting corrugated aluminium sheet 69 is then rewound on to a final coil 64 to complete the process 60. The rewound final coil 64 may either be for the full width of the corrugated aluminium sheet 69 or the sheet may be cut to desired smaller widths and wound on to individual coils. Coils of corrugated flashing material may therefore be supplied as rolls of flashing or may be cut in to specific shaped sections and affixed to cavity trays as desired.

Referring to Figure 7 there is shown an enlarged schematic perspective view of a section of a corrugation roller 70. The corrugation roller 70 is of the type used in the process 60 of making the corrugated aluminium flashing shown in Figure 6. The roller has a number of indentation 72 and ridges 71 arranged thereupon, and these ridges 71 and indentations 72 are arrange in columns. The columns are off-set such that the ridges 71 and indentations 72 on neighbouring columns are not in-line. As the flat aluminium is passed between the corrugation rollers 70 the rollers 70 shape the flat sheet to create off-set corrugated columns on the sheet.

It is to be understood that the invention is not to be limited to the details of the above embodiments, which are described by way of example only. Many variations are possible. -18-

Claims

Claims I. Flashing (10) formed from a substantially weatherproof material, the flashing (10) comprising a plurality of adjoining columns (12), each column (12) comprising corrugations (11) which allow the flashing (10) to be deformable, whereby said corrugations (11) in a first column are off-set with respect to corrugations of an adjoining column.
2. The flashing (10) according to claim 1, wherein each column (12) comprises a plurality of individual corrugations (11) formed by a sequential series of peaks (14) and troughs (13) arranged along a longitudinal axis of each column (12).
3. The flashing (10) according to claim 2, wherein the peaks (14) and troughs (13) in each column (12) are formed identically with regard to their cross-section.*****. 15 S...
4. The flashing (10) according to either claim 2 or claim 3, wherein the peak (14) and trough (13) each have an amplitude in the range from 0.2 cm to 0.8 cm.S SS.
5.S S

: 5. The flashing (10) according to any preceding claim, wherein the depth (27) of the corrugated flashing material (10) is in the range 0.01 cm to 10 cm.
6. The flashing (10) of any preceding claim, where each corrugated column (12) has a -19 -width of less than 20 cm.
7. The flashing (10) according to any preceding claim, wherein the flashing (10) is formed from a substantially flat sheet of material (65).
8. The flashing (10) according to any preceding claim, wherein the corrugations (11) extend substantially across the whole surface of the flashing (10).
9. The flashing (10) according to any of claims 1 to 7, wherein the flashing (10) comprises portions which are not corrugated thereby providing areas suitable for affixing the flashing (10) to a structure.
10. The flashing (10) according to any preceding claim, wherein the flashing (10) *::: : comprises cavity trays (42) affixed thereto.**S**. 15 * *a.
11. The flashing (10) according to any preceding claim, wherein the substantially weatherproof material is selected from aluminium or aluminium alloys, copper, zinc alloy, terne metal, or copper clad lead.

*. aSI * * *
12. The flashing (10) according to claim 11, wherein the substantially weatherproof material is selected from aluminium of grade 1050, 1080, or 1200.

-20 -
13. The flashing (10) according to any preceding claim, wherein the flashing (10) comprises at least one adhesive area arranged on an outer surface, and the adhesive area being capable of affixing the flashing (10) to a desired structure.
14. The flashing (10) according to claim 13, wherein the adhesive area has a removable protective film.
15. The flashing (10) according to any preceding claim, wherein the flashing (10) has a coating/lacquer to provide improved weather resistance properties.
16. Use of the flashing (10) according to any of claims 1 to 15 for weatherproofing a structure.
17. The use of the flashing (10) according to claim 16, wherein the flashing (10) is used for roof flashing, wall flashing, sill flashing, or base flashing.-* * * ** a
18. The use of flashing (10) according to either claim 16 or claim 17, wherein the flashing (10) is cold formed on to the structure. **a.* * * * S.. *
19. A method of manufacturing the flashing (10) of claim I comprising the steps of: providing a substantially weatherproof material; and forming a plurality of adjoining columns (12) in the substantially weatherproof material, each column (12) comprising corrugations (11) which allow the flashing (10) to be deformable; whereby said corrugations (11) in a first column are off-set with respect to corrugations (11) of an adjoining column.
20. The method according to claim 19, wherein the substantially weatherproof material is obtained in an unprocessed flat form (65), and the fiat material (65) is passed through a set of corrugation rollers (62) to form repeating patterns of corrugations (11) arranged in columns (12), where the corrugations (11) of adjoining columns (12) are off-set.
21. Flashing (10) as substantially as hereinbefore described and with reference to the accompanying drawings. *... * Sa S. * * .** * . *. IS � S..SSt. *..S S *S