GB2176513A - Fencing - Google Patents

Abstract

The as disclosed fencing comprising a plurality of generally upright posts 17, 18, 19 of a given width, a plurality of generally horizontal rails, (3 Figure 1) extending between pairs of posts, and pales (28, 29 Figure 9) carried by the rails, the rails being attached to the posts by plate means 12 extending through the respective posts and apertured at each end 13 for releasable attachment to the rails, each plate means having a reduced neck portion 14 intermediate its end and of a width greater than the width of the post, whereby it can be inserted through an asymmetrical aperture 16 in a post, the aperture having a width in one direction such as to accommodate the full width of the plate means to permit the insertion thereof, and a smaller width in another direction to accommodate only the neck portion of the plate means when the latter is rotated so as to retain the same. Also disclosed are other aspects of fencing relating to the arrangement of pales, gravel boards and base means. <IMAGE>

Description

SPECIFICATION Fencing This invention relates to fencing and has particular, but exclusive, reference to acoustic barriers or fencing, such as are used to protect domestic dwellings, for example, from excessive traffic noise which may be produced by road orairtraffic,the latter on take-offand landing.

One common use of acoustic barriers is along the sides of motorways or other busy highways to protect adjacent domestic dwellings, offices etc. from the traffic noise and the most popular type of barrierfor both acoustic and aesthetic reasons is that constructed principally of timber. Concrete barriers are known but they can, to a certain extent, be acousticallytransmissive, and are considered by many to be unsightly compared with timber barriers.

However, certain problems arise with timber barriers, the main one of which isthatoftimber expansion and contraction due to varying climatic conditions. There is a need to ensure that contraction does not result in gaps in the fencing, thus producing localised areas of zero acoustic protection, and to ensure that expansion does not result in buckling with the possibility of the acoustic barrier properties being reduced, if not destroyed, in places. Another problem arises with subsidence which can produce a gap beneath the fence which again destroys the acoustic protection in that region.

The principal object ofthe present invention is to provide acoustic barriers or fencing which can accommodate natural timber expansion and contraction and maintain full acoustic protection afforded by the barriers or fencing.

According to a first aspect of the present invention there is provided fencing comprising a plurality of spaced, generally upright posts, a plurality of generally horizontal rails attached to, and extending between, each pair of posts, and a plurality of generally upright pales each of which is attached only to the rails oven which it extends, and not to other component parts of the fencing, the pales being constructed and arranged such that adjacent pales overlap to an extent which accommodates contraction of the pales without creating gaps in the barrier.

It is known for the pales to be attached not onlyto the rails but also to each other and/or a gravel board, this multi-fixing of the pales causing problems due to differential expansion and contraction between the various components attached together. The first aspect ofthe present invention avoids or minimises this problem by attaching each pale only to the adjacent rails.

The pales may be of T-section with alternate pales reversed, or of general Z-section, in each case the pales providing a barrier of substantially constant thickness throughout and thus generally uniform acoustic properties. Alternativeiy, generally planar pales may be alternated with T-section pales, the planar pales being spaced apart as to accommodate therebetween the stems of the T-section pales, with the crosspieces of the T-section pales providing overlaps between two adjacent planar pales.

The posts are preferably metallicto give structural strength and so as to be rot proof but since metal is acousticallytransmissive, cover boards or pales of the posts can be provided if the basic pales cannot be arranged to cover the posts.

If a section of known fencing needs to be replaced, this presents a considerable problem in that it is difficult, if not impossible, to replace the rails without removing at least one post because ofthe nature of the fixation ofthe rails to the posts. For example, in one known acoustic barrierthe posts have dowels extending therethrough in the general direction of the barrier with the ends of each dowel being received in the ends ofthe adjacent rails which extend from opposed sides of the post. This construction can only be achieved when the barrier is erected from new because rail replacement is impossible without disturbing one or more posts.

According to a second aspect of the present invention there is provided fencing comprising a plurality of generally upright posts of a given width, a plurality of generally horizontal rails extending between pairs of posts, and pales carried by the rails, the rails being attached to the post by plate means extending through the respective posts and apertured at each end for releasable attachment to the rails, each plate means having a reduced neck portion intermediate its end and of a width greater than the width of the post, whereby it can be inserted through an asymmetrical aperture in a post, the aperture having a width in one direction such asto accommodate the full width ofthe plate means to permitthe insertion thereof, and a smailerwidth in another direction to accommodate only the neck portion ofthe plate means when the latter is rotated so as to retain the same.

Conveniently, the posts are metallic and of H-section (or I-section), with the plate means extending through the intermediuate webs of the posts, each web preferably having a plurality of general keyhole-shaped apertures therein through which the associated plate means extend.

This second aspect ofthe invention enables the fencing rails to be assembled and disassembled when the posts have been set in position, thus greatly assisting the original construction procedure and permitting easy repair of any damaged section.

Furthermore, since the width ofthe neck portion is greater than the width of the post or post portion through which plate means extends,the plate means can be tilted to some extent, thus allowing the fencing to be sloped, as opposed to stepped, which is a verv significant advantage. Also, the simplistic nature of the retention ofthe plate means in the posts avoids the need for, and hence cost of, securing means such as bolts.

Acoustic barriers normally have gravel boards which extend along the bottom of the barrier beneath the pales, one gravel board extending between each pair of posts, and it is desirableto have some overlap between the pales and the gravel boards in orderto prevent gapping due to contraction and thus maintain the acoustic properties. In one known arrangement, the gravel board is a composite member comprising two boards of differing widths (which constitute in use the heights ofthe boards).

The two boards are placed on respective sides ofthe palesatthe bottom endsthereofand bolted together through the pales. In addition,thewiderboard is bolted to a foundation member. This sandwich construction means thatthree timber component parts (two gravel boards and one pale) are connected together which is not favoured in view ofthe differential expansion and contraction likely to take place therebetween.

In accordance with a third aspect ofthe present invention there is provided a gravel board forfencing comprising a generally rectangular, elongate member, with one longitudinal edge being recessed along its length from one face of the memberto within the thickness of the member, whereby the remaining portion of that edge provides, in use, an upstanding lip serving to overlap the bottom edges of pales forming part of the fencing.

Preferably, the bottom ofthe recess is chamfered to shed water, as isthetop ofthe lip. The recess chamfer may be less than the lip chamfer and the pales may engage the bottom of the recess.

A gravel board according to this third aspect ofthe present invention only requires fastening to the posts ofthe fencing and when the posts are of H-section (or I-section), the gravel boards may be slotted at each end so as to fit over a postflangeto which the ends may be bolted or otherwise secured. The slotted ends of the gravel boards may be such that the limb defining oneside oftheslot is longerthanthe limb defining the otherside ofthe slotand of a length such that it extends, when in situ, approximatelyto the centre ofthe postfacesothatwhen two gravel boards are fitted to respective sides of a post the face ofthe latter in the region of the gravel boards is substantially entirely covered thereby.

With this arrangement of gravel board, the required overlap with the bottom edges of the poles is achieved in a simple but effective mannerandthe problems ofthe sandwich construction discussed above are avoided.

In orderto ensure thattraffic or other noise does not penetrate a barrier at ground level, it is customary to bury the gravel at least 50 mm. However, ground settlement after barrier erection often results in gaps beneath the gravel boards, thus impairing the acoustic properties ofthe barrier. Very often, barriers are erected on earth banks and soil erosion causes the same problem. Furthermore, buried timber gravel boards are prone to rotting.

According to a fourth aspect ofthe present invention there is provided base meansforfencing comprising elongate members in use extending between respective pairs of generally upright posts of the fencing and being buried in the ground, each member being formed with a channel for reception of the lower edge of a gravel board which also forms part of the fencing.

Thus an overlap is provided between the gravel boards and the base members to accommodate timber contraction.

The base members may be oftimber, steel, concrete or any other material and are preferably provided with one or more drainage holes extending from the channels to outside faces ofthe members in order to drain the channel and thus prevent rotting of the base members and/or gravel boards iftimberis used therefor.

An acoustic barrierforamotorwayand illustrating the various aspect ofthe present invention will now be described in greater detail, byway of example, with reference to the accompanying drawings, in which: Figure l is a partial, schematic front view ofthe barrier as seen from the side opposite to that which is subjected to traffic noise, Figures 2,3, 4and 5are sections on the lines ll-ll, III-III, IV-IV and V-V, respectively, of Figure 1, Figure 6is a plan section through a postofthe barierofFigure 1, Figure 7, is a partial sideviewofa post;; Figure8is a section on the lineVIlI-VIll of Figure7, and Figures 9 and 10 are respective partial plan views of alternative constructions of barrier.

Referring first to Figures 1 to 8 in general but Figures 1 and 2 in particular, the barrier is of timber construction and comprises a plurality of rolled steel (RSJ), generally upright posts 1 of H-section (or I-section) which are set in concrete 2 at regularly spaced intervals, each pair of posts being interconnected byfour generally horizontal rails 3 which are identical except the top rail which has a flat at its top edge to accommodate a capping rail 4.

Generally vertical pales 5 and 6 are secured to the rails 3 by nails (although otherfixings can be employed), it being noted that each pale 5,6 is attached only to the four rails which it spans and to no other component of the barrier. This gives a stronger directfixing as well as avoiding the problem of differential movementwhen morethantwo components are secured together. A gravel board 7 extends between each pair of posts 1 beneath the pales 5, 6, the gravel board sitting in a channel 8 of a base member9which in the main is buried beneath the ground level which is indicated at 11.

Looking now in greater detail at some ofthe components referred to, the rails 3 (which have the normal water-shedding chamfer) are secured to the posts in such a waythatthe posts 1 can first be erected and the rails subsequently attached when the concrete 2 has set which is a distinct advantage over some known barriers in which the posts and intervening bays if the barrier have to be erected simultaneously. Conversely, the attachment ofthe rails3 in this manner allowdismantling of a bay without disturbing one or more posts.

Rail attachment is affected by plate means which are best shown in Figure 8 as comprising a plate 12 apertured at13towardseach end and having an intermediate neck portion 14formed bytwo opposed cut-outs 15 although one cut-out might suffice. Each post 1 has four keyhole-shaped apertures 16 (Figure 7) formed in the central web 17 which joins the front and rearfacesorflanges 18,19 of the H-section posts.

The plates 12 are assembled in the posts 1 by holding generally horizontally and passing them through the respective keyholes 16, i.e. through the widest parts of the keyholes, and then rotating through 90" so that the plates are generally vertical in which position they are retained in position by the cooperation between the neck portions and the post webs 17, wherebythe plates cannot be removed unless they are rotated back th rough 90 (or some other angle which may be used by suitably orienting the keyholes 16). The neck portions 14 in the plates 12 are slightly widerthan the thickness of the post webs 17 and this allows the plates to be tilted, as shown in Figure 8, which is a distinct advantage as it allows the barrier bays to be sloped,to a limited extent, to following ground inclination when necessary.The ends ofthe rails 3 are bolted to respective plates 12 through the apertures 13 in the latter. The plates are preferably of galvanised metal or other non-corrosive material.

With particular reference to Figures 2,4 and 6, each gravel board 7 is intheform of atimberplank having a recess 21 formed along one edge and extending approximately two thirds into the thickness ofthe board,thusforming an upstanding lip 22. The bottom ofthe recess 21 and the top of the lip 22 are formed with water-shedding chamfers, that of the recess being less steep than that of the lip in ordertoform a more convenient seatforthe bottom edges ofthe pales 5,6. Each end of each gravel board 7 is slotted at 23 (best seen in Figure 6)so that it can receive a flange of a post 1.The outer limb 24 defining one side ofthe slot 23 is longer than the limb 25 defining the other side of the slot and is of a length such that it extends approximately halfway across the associated post face. Thus two adjacent gravel boards will substantially cover the face of the associated post 1 in the region ofthe boards. The gravel boards 7 are bolted to the post flanges through the limbs 24 and 25, and the boards sit, as already mentioned, in the channels 8 of the base members 7. This singlefixing at each post is cost effective and the slotting ofthe gravel boards 7 over the post flanges reduce considerably the possibility of timber movement which might otherwise create gaps.As the gravel boards 7 are independent ofthe pales, movement of the latter is unrestricted and no moisture can be trapped which might cause problems of rotting. In order to prevent water collecting in the channels 8 of the base members 7 which may rot the gravel boards 7 and/orthe base members, a plurality of drain holes 20 are provided.

In the barrier illustrated in Figure 1,the pales 5 and 6 are of two different cross-sections. The pales 5 are of rectangular section (i.e. are plain boards),whereas the pales 6 are of T-section. The pales 5 and 6 alternate as illustrated in Figure 3 with the pales 5 being spaced apart so as to receive therebetween the stems ofthe T-section pales 6, the crosspieces of which provide an overlap with adjacent pales 5. Thus any contraction ofthe pales 5,6 will not result in gaps appearing in the barrier, movement of the pales due to expansion and contraction arising from varying climatic conditions being accommodated to the maximum by securing the pales 5, 6only to the rails 3 and not to each other.UnlesstheT-section pales6 are dimensioned such as to meet across the faces ofthe post 1, then a cover strip 26 is used, as shown in Figure 6,to provide acoustic damping at the post faces on the traffic side of the barrier which is indicated by arrow 27 in the drawings.

Figures 9 and 10 are schematic, partial plan views of barriers employing different pales from those illustrated in Figures 1 to 8. In Figure 9, the pales 28 are of Z-section which provide the desired overlap, a cover strip 26 is used as before and a T-section pale 29 is required on one side of each post 1 to maintain the overlap and preserve the general uniformity of thickness of the barrier.

In Figure 10, the pales 31 are all of T-section and again, a cover strip 26 may be provided at each post 1.

As will be seen, the alternate pales 31 are reversed to achieve the required overlap.

It will be seen that the various aspects ofthe present invention give rise to an acoustic barrier or normal fencing which is both simpleto construct and also to dismantle in sections for repair, whilst affording excellent acoustic properties in the sense of absorbing sound waves and not presenting gaps due to timber expansion and contraction, or due to soil subsidence or erosion.

Claims (20)

1. Fencing comprising a plurality of generally upright posts of a given width, a plurality of generally horizontal rails extending between pairs of posts, and pales carried bythe rails, the rails being attached to the posts by plate means extending through the respective posts and apertured at each end for releasable attachment to the rails, each plate means having a reduced neck portion intermediate its end and of a width greater than the width of the post, whereby it can be inserted through an asymmetrical aperture in a post, the aperture having a width in one direction such asto accommodate the full width of the plate means to permitthe insertion thereof, and a smaller width in another direction to accommodate onlythe neck portion of the plate means when the latter is rotated so as to retain the same,

2.Fencing according to claim 1, wherein the posts are metallic and of H-section or l-section with the plate means extending through the intermediate webs ofthe posts.

3. Fencing according to claim 2, wherein each intermediate web of each post has a plurality of general keyhole-shaped aperturestherein through which the associated plate means extend.

4. Fencing comprising a plurality of spaced, generally upright posts, a plurality of generally horizontal rails attached to, and extending between, each pair of posts, and a plurality of generally upright pales each of which is attached onlyto the rails over which it extends, and not to other component parts of the fencing, the pales being constructed and arranged such that adjacent pales overlap to an extent which accommodates contraction ofthe pales without creating gaps in the barrier.

5. Fencing according to claim 4, wherein each pale is of T-section with alternate pales reversed.

6. Fencing according to claim 4, wherein each pale is of Z-section.

7. Fencing according to claim 4, wherein the pales are a mixture of planar pales and T-section pales which are arranged alternatelywith the stem of T-section pales disposed between a pair of planar pales.

8. Fencing according to any ofclaims4to 7, wherein the posts are metallic and are fitted with cover boards or pales to reduce acoustic transmission therethrough.

9. Agravel boardforfencingcomprisinga generally rectangular, elongate member, with one longitudinal edge being recessed along its length from one face ofthe memberto within the thickness ofthe member,wherebythe remaining portion of the edge provides, in use, an upstanding lip serving to overlap the bottom edges of pales forming part ofthe fencing.

10. A gravel board according to claim 9,wherein the bottom ofthe recess is chamfered to shed water, as isthetop ofthe lip.

11. A gravel board according to claim 10, wherein the recess chamfer is less than the lip chamfer.

12. A gravel board according to any of claims 9to 11, wherein each end is slotted to receive, in use, a portion of an adjacentpostforming part of the fencing.

13. A gravel board according to claim 12, wherein the limbs defining each end slotofthe boards of differing lengths such that the longer limbs oftwo adjacent boards, when in situ, extend to the centre of the associated post substantiallyto coverthe face of the latter.

14. Base means for fencing comprising elongate members in use extending between respective pairs of generally upright posts ofthe fencing and being buried in the ground, each member being formed with a channel for reception of the lower edge of a gravel board which also forms partofthefencing.

15. Base means according to claim 14, wherein at least one drainage hole is provided extending from the channels to an outside face ofthe member.

16. Base meansforfencing substantially as herein particularly described with reference to the accompanying drawings.

17. Fencing comprising base means according to anyofclaims 14to 16.

18. A gravel board for fencing substantially as herein particularly described with reference to the accompanying drawings.

19. Fencing comprising gravel boards according toanyofclaims9to 13.

20. Fencing substantially as herein particularly described with reference to the accompanying drawings.