PALE

Abstract

A pale (4) for a palisade fence, the pale (4) comprises a longitudinal web (5) and two longitudinal side portions (6, 7), respective first and second longitudinal side portions (6, 7) extending from each side of the longitudinal web (5) at an angle greater than 70 degrees and less than or equal to 90 degrees.

Claims

1. A pale for a palisade fence, the pale comprising a longitudinal web and two longitudinal side portions, respective first and second longitudinal side portions extending from each side of the longitudinal web at an angle greater than 65 degrees and less than or equal to 90 degrees.

2. A pale according to claim 1, wherein the pale has a thickness of between about 1 mm and about 2 mm.

3. A pale according to claim 1, wherein the pale satisfies the requirements of British Standard 1722-12: 2006 regarding general purpose (GP) palisade fences and/or security (SP) palisade fences.

4. A pale according to claim 1, wherein during a three-point bending test the pale has a maximum deflection at its middle of less than or equal to 8 mm when subjected to a load of 2.5 kN, or of less than or equal to 10 mm when subjected to a load of 3.5 kN.

5. A pale according to claim 1, wherein the pale is formed from metal.

6. A pale according to claim 5, wherein the metal is steel and has a yield stress greater than 235 N/mm.sup.2.

7. A pale according to claim 1, wherein the pale is cold formed by rolling or press braking.

8. A pale according to claim 1, wherein the first longitudinal side portion comprises first and second longitudinal side walls connected to one another at one of their longitudinal edges by a further longitudinal web.

9. A pale according to claim 8, wherein the second longitudinal side portion comprises first and second longitudinal side walls connected to one another at one of their longitudinal edges by a further longitudinal web.

10. A pale according to claim 8, wherein one or both of the further longitudinal webs is arched or pointed.

11. A pale according to claim 8, wherein one or both of the further longitudinal webs is substantially flat.

12. A pale according to claim 8, wherein the second longitudinal side wall comprises a free longitudinal edge portion.

13. A pale according to claim 12, wherein the free longitudinal edge portion comprises a lip comprising a free longitudinal edge of the second longitudinal side wall.

14. A pale according to claim 1, wherein the longitudinal web is substantially flat.

15. A pale according to claim 1, wherein one or both longitudinal side portions comprise strengthener comprising a longitudinal formation and/or one or more projections and/or depressions.

16. A pale according to claim 1, wherein the pale has a face to view greater than 65 mm and less than 155 mm.

17. A pale according to claim 1, wherein the pale has a cross-sectional area of less than 205 mm.sup.2 extending along a major proportion of its length.

18. A pale according to claim 1, wherein the pale comprises a security head.

19. A palisade fence comprising two posts, at least one rail extending between the posts and at least one pale according to claim 1 connected to the rail.

20. A kit of parts for a palisade fence, the kit comprising two posts, at least one rail and at least one pale according to claim 1.

Description

BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS

[0040] Embodiments of the invention will now be described by way of example only with reference to the accompanying drawings in which:

[0041] FIG. 1 is a front elevation of a prior art palisade fence;

[0042] FIG. 2 is a sectional view of a prior art pale;

[0043] FIG. 3 is a sectional view of a pale according to a first embodiment of the invention;

[0044] FIG. 4 is a perspective view of a prior art test rig used to test pales;

[0045] FIGS. 5a is a sectional view of a pale not according to the invention FIGS. 5b and 5c are sectional views of pales according to alternative embodiments of the invention;

[0046] FIG. 6 is a plot of the results of testing the pales of FIGS. 5a to 5c;

[0047] FIG. 7 is a sectional view of a pale according to an alternative embodiment of the invention;

[0048] FIG. 8 is a plot of the results of testing the pales of FIG. 2 and FIG. 7;

[0049] FIG. 9a is a sectional view of a prior art pale and FIGS. 9b and 9c are sectional views of pales according to alternative embodiments of the invention;

[0050] FIGS. 10 and 11 are plots of the results of testing the pales of FIG. 7 formed from steels with different yield strengths; and

[0051] FIG. 12 depicts front elevation views of six different security heads of pales according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

[0052] Referring now to FIG. 2, there is shown a prior art W-shaped pale 4′ which was cold roll formed from a steel strip of width 112.77 mm and thickness t of 1.85 mm. The pale 4′ includes a substantially flat, longitudinal central web 5′ with first and second longitudinal side portions 6′, 7′ projecting from either side of the central web 5′ at an angle θ′ of 62°. The formed pale 4′ has a face to view d of 65.00 mm and is commercially available from Hadley Industries PLC as UltraPALE®200.

[0053] The first longitudinal side portion 6′ includes first and second longitudinal side walls 60′, 61′ connected to one another by an arched, further longitudinal web 62′ extending between respective proximate longitudinal edges. Longitudinally extending corrugations 63′ are included at the midpoint of the first and second longitudinal side walls 60′, 61′. A free, longitudinal edge portion 64′ of the second, longitudinal side wall 61′ extends beyond a plane P defined by the substantially flat, longitudinal central web 5′. The free, longitudinal edge portion 64′ includes an inturned lip 65′ with a free longitudinal edge 66′ which is adjacent a first, inner surface of the second, longitudinal side wall 61′.

[0054] The second longitudinal side portion 7′ includes first and second longitudinal side walls 70′, 71′ connected to one another by an arched, further longitudinal web 72′ extending between respective proximate longitudinal edges. Longitudinally extending corrugations 73′ are included at the midpoint of the first and second longitudinal side walls 70′, 71′. A free, longitudinal edge portion 74′ of the second, longitudinal side wall 71′ extends beyond the plane P defined by the substantially flat, longitudinal central web 5′. The free, longitudinal edge portion 74′ includes an in-turned lip 75′ with a free longitudinal edge 76′ which is adjacent a first, inner surface of the second, longitudinal side wall 71′.

[0055] In use, the pale 4′ is attached to rails 3 (as shown in FIG. 1) at two locations along the substantially flat, longitudinal central web 5′ via fastening devices (not shown), commonly rivets or bolts.

[0056] Referring now to FIG. 3, there is shown, according to one embodiment of the invention, an improved W-shape pale 4, where like references (absent the prime (′)) refer to like features which will not be described further herein. The first and second longitudinal side portions 6, 7 extend from the substantially flat, longitudinal central web 5 (e.g. from a plane

[0057] P parallel therewith) at an angle θ which is greater than 64 degrees and less than or equal to 90 degrees, say greater than 65 degrees and less than 85 degrees, for example greater than 66 degrees and less than 80 degrees, e.g. greater than 67 degrees and less than 75 degrees. Preferably, the angle is greater than 70 degrees and less than 90 degrees.

[0058] The further longitudinal web 62 of the first longitudinal side portion 6 is substantially flat in this embodiment. The free, longitudinal edge portion 64 of the second longitudinal side wall 61 extends to lie in line with a plane P defined by the substantially flat, longitudinal central web 5. The free, longitudinal edge 66 of the second, longitudinal side wall 61, is turned in to contact the first, inner surface thereof.

[0059] The further longitudinal web 72 of the second longitudinal side portion 7 is substantially flat in this embodiment. The free, longitudinal edge portion 74 of the second longitudinal side wall 71 extends to lie in line with a plane P defined by the substantially flat, longitudinal central web 5. The free, longitudinal edge 76 of the second, longitudinal side wall 71, is turned in to contact the first, inner surface thereof.

[0060] The pale 4 has a face to view d of between 65 and 155 mm, for example between 65 and 120 mm, e.g. between 65 and 95 mm, say 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79 or 80 mm.

[0061] The pale 4 has a thickness t greater than 1.0 mm and less than 2.5 mm, say greater than 1.0 mm and less than 2.0 mm, for example greater than 1.0 mm and less than 1.9 mm, e.g. from 1.1 to 1.75 mm thick.

[0062] The pale 4 is formed from a steel having a yield stress greater than 235N/mm.sup.2.

[0063] Testing:

[0064] Pales according to the invention (as well as prior art pales) were tested as per the following test: [0065] Test—Three point bending test [0066] A rig 100 according to BS 1722-12:2006 was set up as shown in FIG. 4, comprising a pair of parallel support rollers SR spaced by 600 mm with a loading pad LP equidistant therebetween and parallel thereto. Pales to be tested were placed upon the support rollers SR with the loading pad LP acting against the uppermost surface of the pale under test. A force of 2.5 kN was applied to each test sample and the deflection thereof measured. A force of 3.5 kN was then applied to each test sample and the deflection thereof measured. Six test specimens of each type of pale were tested in this rig 100, with each sample tested individually. Three samples were tested with the central web uppermost and three samples were tested with the central web downmost. The results were averaged for each type of pale under test.

[0067] Referring now to FIGS. 5a to 5c (integers similar or identical to the first embodiment are identified by a preceding ‘1’ for the embodiment of FIG. 5a, a ‘2’ for the embodiment of FIG. 5b and a ‘3’ for the embodiment of FIG. 5c), there are shown three simplified pales 14, 24, 34. The first and second longitudinal side portions 16, 26, 36, 17, 27, 37 of each of the simplified pales 14, 24, 34 include only first side walls 160, 260, 360, 170, 270, 370. Furthermore, the first side walls 160, 260, 369, 170, 270, 370 are free from the longitudinally extending corrugations 63, 73 as shown in the pale 4 of FIG. 3.

[0068] The first and second longitudinal side portions 16, 17 of the pale 14 shown in FIG. 5a extend at an angle θ of 62° from the longitudinal central web 15. The pale 14 is a simplified approximation of the prior art pale 4′ shown in FIG. 2. The first and second longitudinal side portions 26, 27 of the pale 24 shown in FIG. 5b extend at an angle θ of 72° from the longitudinal central web 25. The first and second longitudinal side portions 36, 37 of the pale 34 shown in FIG. 5c extend at an angle θ of 82° from the longitudinal central web 35.

[0069] Batches of pales 14, 24, 34 as shown in FIGS. 5a, 5b and 5c were manufactured by brake pressing according to the following characteristics:

TABLE-US-00001 TABLE 1 Batches of simplified pales Steel Pale yield Batch angle stress name (⊖) (N/mm.sup.2) A 62° 290 B 72° 290 C 82° 290 D 62° 550 E 72° 550 F 82° 550

[0070] Each batch of pales 14, 24, 34 was tested using the test rig 100 as described above, with the results shown in FIG. 6 and Table 3 below.

TABLE-US-00002 TABLE 3 Average maximum force resisted by pales 14, 24, 34 Average maximum force (N) Batch resisted A  722.00 B  813.33 C  884.67 D 1216.67 E 1350.00 F 1420.00

[0071] As can be seen from the results shown in FIG. 6, batch C (having an angle of 82°) resisted a greater load before deflecting to a similar extension as batch B (having an angle of 72°) which in turn resisted a greater load before deflecting to a similar extension as batch A (having an angle of 62°). Similarly, batch F (having an angle of 82°) resisted a greater load before deflecting to a similar extension as batch E (having an angle of 72°) which in turn resisted a greater load before deflecting to a similar extension as batch D (having an angle of 62°). Therefore, increasing the angle θat which the longitudinal side portions 16, 26, 36, 17, 27, 37 extend from the longitudinal central web 15, 25, 35 resulted in increased resistance to deflection under load. However, the improvement to resistance under load was greater between batches A and D (θ=62°) and batches B and E (θ=72°) than between batches B and E (θ=72°) and batches C and F (θ=82°) (i.e. ΔForce.sub.BA>ΔForce.sub.CB and ΔForce.sub.ED>ΔForce.sub.FE. Therefore, it appears as though the benefit of increasing the angle θ may decline as the angle θ approaches 90°.

[0072] Each of batches D, E and F (manufactured from steel with a yield stress of 550 N/mm.sup.2) demonstrated increased resistance to deflection under load over their corresponding (according to the same angle θ) batches A, B and C (manufactured from steel with a yield stress of 290 N/mm.sup.2). Therefore, increasing the yield stress of the steel from which the pales 14, 24, 34 were manufactured resulted in increased resistance to deflection under load. Furthermore, the ratio of increase between corresponding batches (having the same angle θ) is similar, suggesting that the increase in resistance to deflection obtained by increasing the yield stress of the steel is independent (or only marginally dependent) of the effect of altering the angle θ.

[0073] Moreover, batches B (θ=72°) and C (θ=82°) demonstrate increased resistance to load at smaller distances of deflection than does batch D (θ=62°) even though batches B and C were manufactured from steel with a yield stress of 290 N/mm.sup.2 while batch D was manufactured from steel with a yield stress of 550 N/mm.sup.2. Without wishing to be bound by any theory it may therefore be the case that at smaller distances of deflection the angle θof the pale 14, 24, 34 has a more significant effect on resistance to deflection than does the yield stress of the steel from which the pale 14, 24, 34 is manufactured. This is a surprising result given that the yield strength of the steel for batches B and C is about half of that of batch D. Furthermore, it is possible to compare the average maximum forces resisted by the pales 14, 24, 34 (as shown in Table 3) for pales 14, 24, 34 having the same angle θ. This comparison reveals that increasing the yield stress from 290 N/mm.sup.2 to 550 N/mm.sup.2 as from batch A to D (θ=62°) increased the maximum force resisted by 1.685 times, as from batch B to E (θ=72°) increased the maximum force resisted by 1.660 times, and as from batch C to F (θ=82°) increased the maximum force resisted by 1.605 times. Clearly, as the angle e increases the effect of increasing the yield stress becomes less significant. Therefore, as the angle θ increases, the effect of increasing the angle θ has a decreasing relative effect (with respect to increasing the yield stress of the steel) on the maximum force resisted by the pales 14, 24, 34.

[0074] Referring now to FIG. 7 (integers similar or identical to the first embodiment shown in FIG. 3 are identified by a preceding ‘4’), there is shown a pale 44 which differs from the pale 4 shown in FIG. 3 in that the first and second longitudinal side walls 460, 470, 461, 471 of the first and second longitudinal side portions 46, 47 are free from longitudinally extending corrugations. Furthermore, the free, longitudinal edge portions 464, 474 of the second longitudinal side walls 461, 471 do not include an in-turned lip.

[0075] Tests were conducted of pales 44 as shown in FIG. 7 and prior art UltraPALE 200 pales 4′ as shown in FIG. 2, with characteristics as follows:

TABLE-US-00003 TABLE 3 Tested pale characteristics UltraPALE 200 1.2 mm 1.7 mm Characteristic pale 4′ pale 44 pale 44 Thickness t (mm) 1.85 1.19 1.72 Cross-sectional 208.62 153.33 212.51 area (mm.sup.2) Angle ⊖ 62.0 71.0 71.0

[0076] Results of Testing:

[0077] Referring now to FIG. 8, there are shown the results of testing of pales 4′, 44 with characteristics shown in Table 1 using the test rig 100 shown in FIG. 4. The 1.2 mm pale 44 test results are denoted in line form for face up testing (labelled as G1) and in dashed line form for face down testing (labelled as G2). The 1.7 mm pale 44 test results are denoted in line form for face up testing (labelled as H1) and in dashed line form for face down testing (labelled as H2). The UltraPALE 200 pale 4′ test results are denoted in line form for face up testing (labelled as J).

[0078] As can be seen from the results, both the 1.2 mm pale 44 (both face up and face down) and the 1.7 mm pale 44 (both face up and face down) provide greater resistance to deflection than does the prior art pale 4′ for deflections less than or equal to 8 mm.

[0079] The 1.2 mm pale 44 withstood an average load of 2.803 kN before deflecting by 8 mm, while the prior art pale 4′ withstood an average load of only 2.563 kN before deflecting by 8 mm. Therefore, although both pales 4′ 44 may be classified as suitable for use in general purpose palisade fencing the 1.2 mm pale 44 achieved a greater resistance to deflection.

[0080] The 1.2 mm pale 44 (face up) provides greater resistance to deflection than does the prior art pale 4′ (face up) for deflections less than or equal to 10 mm. Moreover, the 1.2 mm pale 44 (face down) provides very similar resistance to deflection to the prior art pale 4′ (face up) for deflections up to 10 mm.

[0081] Furthermore, this similarity of performance was achieved even though the UltraPALE 200 pale 4′ has an average cross-sectional area of 208.62 mm.sup.2 while the 1.2 mm pale 44 has an average cross-sectional area of only 153.33 mm.sup.2, representing a 26.5% reduction in area and therefore in material usage. Without wishing to be bound by any theory it is believed that the increase in the angle θ from 62.0° to 71.0° results in increased resistance to localised deformation around the first and second longitudinal side portions 46, 47 leading to a subsequent reduction in overall deflection.

[0082] The 1.7 mm pale 44 demonstrates even greater resistance to deflection than does the 1.2 mm pale 44. Indeed, the 1.7 mm pale 44 exceeded both a 2.5 kN load before deflecting by 8 mm and a 3.5 kN load before deflecting by 10 mm. The 1.7 mm pale 44 therefore successfully passed both the GP and SP palisade fencing deflection tests, in contrast to the prior art pale 4′ which deflected by 10 mm at a load less than 3.5 kN. Accordingly, the 1.7 mm pale 44 could have been made even thinner (and thereby further reduce cross sectional area) and still surpass the results of the prior art pale 4′ and meet both the SP and GP standards.

[0083] Furthermore, neither the 1.2 mm nor the 1.7 mm pales 44 included longitudinally extending corrugations or longitudinal edge portions 464, 474 with in-turned lips, in contrast to the prior art pales 4′. Without wishing to be bound by any theory, it is believed that the in-turned lips 65′, 75′ further strengthen the prior art pale 4′, whilst the longitudinally extending corrugations 63′, 73′ provide increased resistance to deflection under loading. Therefore, were the 1.2 mm and 1.7 mm pales 44 to include either or both of these features they would have produced further improved results over the prior art pales 4′. Moreover, the 1.2 mm and 1.7 mm pales 44 were manufactured by break pressing whilst the prior art pales 4′ were manufactured by cold roll forming.

[0084] Referring now to FIGS. 9a to 9c (integers similar or identical to the first embodiment are identified by a preceding ‘5’ for the prior art pale of FIG. 9a, a ‘6’ for the embodiment of FIG. 9b and a ‘7’ for the embodiment of FIG. 9c), there are shown three pales 54, 64, 74 with the same face to view d of 70.0 mm and width w of longitudinal central web 55, 65, 75. However, the prior art pale 54 shown in FIG. 9a has first and second longitudinal side portions 56, 57 which extend from either side of the longitudinal central web 55 at an angle θ of 62°, whilst the pale 64 according to the invention shown in FIG. 9b includes an angle θ of 72° and the pale 74 according to the invention shown in FIG. 9c includes an angle θ of 82°.

[0085] By substantially maintaining the face to view d of the pales 64, 74 shown in FIGS. 9b and 9c relative to the prior art pale 54 shown in FIG. 9a the same number of pales 54, 64, 74 are required for a given length of fencing whilst substantially maintaining the gap T between adjacent pales 54, 64, 74 (see FIG. 1). Clearly, increasing the number of pales 54, 64, 74 in any given length of fencing would result in an increase in the volume of steel required (all other factors remaining the same) and hence an increase in the expense of a palisade fence 1 thus formed. Therefore, by maintaining the number of pales 64, 74 required in any given length of fencing relative to the prior art pales 54 this increase in expense is avoided.

[0086] In order that the pale 64 shown in FIG. 9b maintains the same face to view d as the prior art pale 54 shown in FIG. 9a the further longitudinal webs 662, 672 have a relatively increased width. The pale 74 of FIG. 9c demonstrates this increase even more markedly. Therefore, it will be understood that increasing the angle θ requires an increased width of strip in order to maintain the same face to view d. Consequently, for pales 54, 64, 74 having the same thickness t increasing the angle θ whilst maintaining the face to view d dimension results in an increase in the cross-sectional area and consequently in the volume of steel used.

[0087] Balancing the angle θ, thickness t, strength and face to view d of the pale allows a fence to be produced which satisfies the applicable standards and substantially reduces the amount of pale material used as compared to the prior art. Accordingly, it has been surprisingly found that a slight but significant change in geometry can lead to pales which demonstrate increased resistance to deflection during loading and/or require reduced quantities of pale material for their construction in comparison with prior art pales.

[0088] Referring now to FIGS. 10 and 11, there are shown the results of testing 1.2 mm thick and 1.7 mm thick pales 44 as shown in FIG. 7 formed from steels with different yield stresses. It can be seen from FIGS. 10 and 11 that increasing the yield stress of the steel used results in pales 44 having increased resistance to deflection under loading.

[0089] It is further shown from FIG. 10 that the 1.2 mm thick pale 44 (with test results labelled K1) needs to be formed from a steel with a yield stress of 306 N/mm.sup.2 in order to deflect by less than 8 mm when subjected to a load of 2.5 kN (and hence satisfy the GP fencing requirement of the aforementioned British Standard). The 1.7 mm thick pale 44 (with test results labelled L1) needs to be formed from a steel with a yield stress of less than 280 N/mm.sup.2 (which has been extrapolated from the results shown in FIG. 10 to be 199 N/mm.sup.2) in order to satisfy the same GP fencing requirement.

[0090] From FIG. 11 it is shown that the 1.2 mm thick pale 44 (with test results labelled K2) needs to be formed from a steel with a yield stress of 436 N/mm.sup.2 in order to deflect by less than 10 mm when subjected to a load of 3.5 kN (and hence satisfy the SP fencing requirement of the British Standard). The 1.7 mm thick pale 44 (with test results labelled L2) needs to be formed from a steel having a yield stress of only 292 N/mm.sup.2 in order to satisfy the same SP fencing requirement.

[0091] As shown in Table 2 above, a 1.2 mm thick pale has a smaller cross-sectional area than does a 1.7 mm thick pale, and hence a smaller volume. Therefore, a 1.2 mm thick pale requires less steel than does a 1.7 mm thick pale, with a consequently reduced expense of steel and a reduced weight of the pale (and hence reduced expense of transportation). However, and in order that the pale satisfies the requirements of the British Standard for GP and/or SP fencing, the yield stress of steel used for a 1.2 mm thick pale should be higher than the yield stress of steel used for a 1.7 mm thick pale. It will be appreciated that increasing the yield stress of steel results in a more expensive metal. Therefore, although a 1.7 mm thick pale requires more steel than does a 1.2 mm thick pale the steel required by the 1.7 mm thick pale to satisfy the requirement of the British Standard of GP and/or SP fencing is less expensive per volume than is the steel required by a 1.2 mm thick pale. Furthermore, formation of pales using steel with higher yield stresses requires more force and consequently (without wishing to be bound by any theory) may result in greater tool wear, leading to shorter tool life and consequent increased expense (e.g. according to calculations, 1.2 mm thick mild steel (S275) requires a force of 1.86 kN to form a 90° bend in a 20 mm length, whereas a different steel (S235) requires a force of 1.57 kN, the corresponding forces being 3.24 kN and 2.65 kN for a 1.7 mm thick steel.

[0092] As is explained above, increasing the angle θ results in increased resistance to deflection under loading (as shown in FIG. 6). Therefore, with an increased angle θ the thickness t of a pale can be reduced whilst maintaining the same or generating an enhanced resistance to deflection under loading. By reducing the thickness t of the pale the cross-sectional area and consequently the volume of steel used is also reduced. However (and as explained above), in order to maintain the same face to view d at an increased angle θ the strip width must be increased, consequently increasing the cross-sectional area and hence the volume of steel used. However, by using a steel having a higher yield stress it is possible to reduce the thickness t of the pale and hence reduce the quantity of steel used. It has been surprisingly found that all of the above factors are interrelated and that it is most beneficial to provide pales having an angle θ greater than 64° or 65°, preferably greater than 70°, but less than 90°, say less than 85°.

[0093] Referring now to FIG. 12, there are shown six different security heads suitable for the pales 4 shown in FIG. 1. Head (a) shows a rounded and notched head, head b shows a rounded head, head c shows a plain, square head, head d shows a pointed head, head e shows a triple pointed and splayed head and head f shows a triple pointed, splayed and returned head.

[0094] It will be appreciated by those skilled in the art that several variations to the aforementioned embodiments are envisaged without departing from the scope of the invention. For example, although only a single longitudinal extending corrugation 63, 73 is shown in each longitudinal side wall 60, 70, 61, 71 of the pale 4 shown in FIG. 3 this need not be the case and instead there may be any suitable number of longitudinally extending corrugations 63, 73, for example 0, 1, 2, 3, 4, 5, 6, etc. Additionally or alternatively, although the longitudinally extending corrugations 63, 73 are shown in the pale 4 at the midpoint of the longitudinal side walls 60, 70, 61, 71 this need not be the case and instead the longitudinally extending corrugations 63, 73 may be included at any suitable location of said longitudinal side walls 60, 70, 61, 71.

[0095] It will also be appreciated by those skilled in the art that any number of combinations of the aforementioned features and/or those shown in the appended drawings provide clear advantages over the prior art and are therefore within the scope of the invention described herein.