Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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FIELD OF THE INVENTION
This invention relates to a picket fence.
BACKGROUND OF THE INVENTION
Picket fences have traditionally been made from
wood. Whilst wood enables a relatively simply construction
to be provided, it has various disadvantageous. Wood is
subject to rot. Consequently, after erection of the fence,
it has to be painted and then repainted at regular intervals,
to keep the fence in good eondition. Also, assembly of a
wooden fence is time eonsuming. Usually, the individual
pieket and horizontal rails have to be cut to length, and
then assembled. If a uniform and neat appearence is to be
provided, care has to be taken when eutting the piekets and
rails. The fenee is then assembled using nails or serews,
whieh is relatively time consuming. Such a construetion also
eannot readily be disassembled, and then reassembled at an
alternative loeation.
Various proposals have been made for forming pieket
fenees and the like from other materials, notably steel and
U.K. Patent No. 29,939 of 1897 (Miller), U.S. Patent Nos.
30,507 (Stratton), 966,969 (Webb), 2,766,967 (Roberts),
2,919,112 (Cofield), 3,095,184 (Boxberger), 3,212,754 (Revell
et al), 3,411,752 (Bos) and applieant's U.S. Patent No.
4,625,948 diselose fence or like constructions.
The Miller U.K. Patent No. 29,939 diseloses feneing
whieh is eapable of aeeomodating itself to the inclination of
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the ground on which it is erected and incorporates upper and
lower longitudinal, channel section bars which receive a
plurality of equidistantly arranged vertical bars of angle
iron. The vertical bars are received in the upper and lower
longitudinal bars in holes of shapes corresponding to that of
the vertical bars and of a size sufficient for the vertical
bars to fit loosely therein. The vertical bars are retained
in the longitudinal bars by means of tongues produced by
piercing the vertical bars. The tongues are located such
that they project respectively over the lower longitudinal
bar and under the upper longintudinal bar.
The Stratton U.S. Patent No. 30,507 discloses a
picket fence in which vertical pickets are mounted on upper
and lower transverse rails by means of pairs of hooks
provided on the pickets and adapted for f itting into
corresponding notches of the rails. As with the Miller
patent discussed above, it is claimed that the disclosed
fence contruction admits of the raising or lowering of the
ends of the transverse rail to suit varieties of grade.
The Webb U.S. Patent No. 966, 969 relates to a line
and corner fence post and bracer that incorporates posts with
horizontal braces extending therebetween. Each post includes
a plurality of upstruck tongues or clips arranged in pairs
and normally utilized for retaining line wires in position,
but also for anchoring a longitudinal brace strip. In the
main embodiment, however, the brace strips are located in
openings formed in flanges of the posts.
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The Roberts U.S. Patent No. 2,766,967 dlscloses a
knock down fence construction, that incorporates horizontal
metal straps with tabs punched therein. It also has vertical
slats, with notches cut in the edges. These notches
correspond to the punch tabs, and the slats are bowed, to
enable them to engage the tabs. The construction is intended
as a light weight low fence for the edge of flowerbeds and
the like.
The Cofield U.S. Patent No. 2,919,112 discloses a
collapsable fence arrangement. For this purpose, horizontal
stringers and vertical pickets are rivetted together, to
enable relative rotation therebetween.
The Boxberger U.S. Patent No. 3,095,184 discloses a
fence construction to be fabricated almost entirely of sheet
metal. Two extruded stringers of stepped channel shape are
mounted to extend in horizontal directions and are vertically
spaced apart. The stringers include elongated slots for
receiving the hook shaped end portions of vertical slats of
heavy gauge sheet metal.
The Revell U.S. Patent No. 3,212,754 discloses an
interlocking fence structure. A top rail has specially
formed slots and tongues, for engaging vertical pickets. The
pickets similarly have a complex cross-section and three
projections for securing them in the top rail.
l~U~,y~
The Bos U.S. Patent No. 3,411,752 d1scloses a
guardrail construction, such as a balcony balustrade. Here,
generally I-section vertical members are provided. These
members are accomodated in corresponding openings of top and
bottom horizontal rails. Pins secure the vertical members in
the horizontal rails. To cover the tops of the vertical
members protruding through the top horizontal rail a sheet
form handrail is provided.
Applicant's U.S. Patent No. 4,625,948 discloses a
picket fence construction having transverse rails and a
plurality of pickets adaped to be mounted in the rails. The
pickets are hung by means of a tongue and engaging link
arrangement. The rail includes a tongue for each picket, and
each picket includes an engaging link, or alternatively the
tongues and links are reversed.
SUMMARY OF THE INVENTION
According to a first aspect of the present invention
there is provided a fence construction comprising a first
transverse rail provided with a plurality of mounting
locations for mounting a plurality of pickets to the rail. A
mounting location is provided for each picket and has
vertically and horizontally spaced opposing first and second
surfaces, each picket being provided with corresponding
oppositely directed first and second surfaces. The
downwardly directed first surface is adapted for engaging the
respective first surface of a first mounting location and the
second surface is adapted for engaging the respective second
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surface of the first mountlng locatlon. The dlameter of each
picket lS less than the spacing of the respective first and
second surfaces of the first mounting location to allow an
inclined picket to pass therebetween and thus permit the
picket to be located on the rail. Retaining means are also
provided for retaining the pickets on the rail in a
substantially upright orientation and retaining the
respective first and second surfaces of each picket in
engagement with the first and second surfaces of the first
mounting location.
Preferably, each first mounting location of the
first transverse rail is provided with a downwardly directed
third surface and each picket has a corresponding upwardly
directed surface for engaging a respective third surface of
the transverse rail to prevent withdrawal of the upright
picket from the rail.
In a preferred embodiment, the first transverse rail
includes an inclined member and the first mounting locations
are in the for~ of circular apertures in the inclined member.
The pickets may also be of circular cross section and are of
slightly smaller diameter than the apertures, the downwardly
directed first surfaces and the upwardly directed third
surface of each picket being provided at a recess formed on
one side of the picket and the second surface being formed on
the opposite side of the pic~et.
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The retainlng means are prefera~ly in the form of a
second transverse rail whlch may be provided with a mounting
locatlon, similar to the mounting location of the first
transverse rail for engaging corresponding surfaces of the
picket.
In a further aspect of the present invention each
picket has first and second attached arms. In addition to
the first mounting locations, the first transverse rail is
further provided with a plurality of second mounting
locations, one for the second arm of each picket. The
configuration of the first arms of the pickets permit at
least some degree of rotation between the rail and the first
arms and the configuration of the second arms of the pickets
permit at least some vertical movement between the rail and
the second arms, permitting the rail to be inclined while the
pickets are maintained in a substantially upright
configuration. Thus this aspect of the invention permits a
fence to be constructed on an inclined surface while the
pickets are maintained in an upright orientation.
According to a still further aspect of the present
invention is provided a fence construction comprising first
and second transverse rails and a plurality of resilient
pickets, each picket having first and seccnd attached arms
for mounting on the rails. The arms of each picket are
biased to assume a first confirguration, and at least one of
the transverse rails is arranged to retain the arms in a
second configuration. The resulting tension in each of the
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pickets tends to locate the pickets securely relative to the
rails.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other aspects of the invention will now be
described, by way of example, with reference to the
accompanying drawings, in which:
Figure 1 shows a fence construction according to a
preferred embodiment of the present invention;
Figure 2 is a view from above and from the front of
a transverse rail of the fence construction of Figure l;
Figure 3 is a view of a first form of picket of the
fence construction of Figure l;
Figure 4 is a sectional view on line 4-4 of Figure
3;
Figure 5 is a view of a second form of picket of the
fence construction of Figure 1;
Figures 6 and 7 illustrate stages in the assembly of
the fence construction of Figure l;
Figure 8 shows a fence construction of a further
preferred embodiment of the present invention;
Figure 9 shows a form of picket of the fence
construction of Figure 8;
Figure 10 shows, partly in section, a stage in the
assembly of the fence construction of Figure 8; and
Figure 11 is a side view of the picket of Figure 9.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Reference is first made to Figure 1 of the drawings
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which illustrates a fence construction ln accordance with a
first preferred embodiment of the present invention. The
fence construction, generally indicated as 10, is mounted
between two upright posts 12, 14 and comprises first and
second vertically spaced transverse rails 16, 18 and a
plurality of pickets 20, 22. Two forms of pickets are
illustrated in Figure 1: two simple rod-like pickets 20; and
five inverted U-shaped pickets 22.
The posts 12, 14 do not form part of the invention
and simply serve as supports for the transverse rails 16, 18.
Their function could be performed equally well by posts or
supports of some other form.
The transverse rails 16, 18 extend between the posts
12, 14 and are secured thereto by means of any suitable
fastening 17. Referring now also to Figure 2 of the
drawings, the rails 16, 18 are formed of lengths of angle
iron, each comprising an inclined front member 24, 25 and a
shorter inclined rear member 26, 27, perhaps best illustrated
in Figure 6 of the drawings.
Each front member 24, 25 includes a plurality of
circular holes providing mounting locations for the pickets.
The two holes 28, 30 to the right of Figure 2 are for
mounting the rod-like pickets 20, while the two remaining
pairs of holes 32, 34 and 36, 38 are for mounting the
inverted U-shaped pickets 22.
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A rod-~ike plcket 20 is lllustrated ~n Figures 3,
which shows the first and second mounting locations in the
forms of recesses 40, 42 provided on the picket 20 for
engaging corresponding mounting locations or holes 28, 29 of
the respective transverse rails 16, 18. If referenee is made
to Figure 4 of the drawings it will be noted that the picket
20, formed of sheet tube, has a eireular eross section. The
recesses 40, 42 are formed by pressing the tube to form an
area of reduced cross section and to form an elliptieal
surfaee 44.
Figure 5 illustrates a second form of picket 22
shaped as an inverted U and having first and second attaehed
arms 46, 48. The pieket 22 is, in effeet, similar to two
rod-like pickets 20 joined together, and each arm is provided
with a respeetive first mounting location or recess 50, 51
providing respective first, second and third surfaces and a
lower second mounting loeation or recess 52, 53, providing
eorresponding respeetive fourth, fifth and sixth surfaees.
The interaction between the holes in the rails 16,
18 with the recess of the pickets 20, 22 will now be
described with reference to Figures 6 and 7 which illustrate
various stages in the assembly of a fence. Figure 6 shows
the first arm 46 of pieket 22 mounted on the first and se~ond
rails 16, 18. The diameter of the arm 46 is slightly less
than the diameter of the hole 32, preferably to provide a
elearance of approximately 1/16", sueh that the picket 22 may
be inelined and passed through the hole 32 in the direction
shown by arrow A, as is illustrated in chain-dotted outline
in Figure 6. The arm 46 is passed through the hole 32 until
the recess 50 is adjacent the lower edge of the hole. At
this point, the picket 22 is rotated to a substantially
upright orientation in which the recess 50 in the picket 22
co-operates with the hole edges to retain the picket on the
rail 16. Functionally, the hole edge provides first and
second opposing surfaces 54, 56 for engaging corresponding
oppositely directed first and second surfaces 58, 60 of the
arm 46. The first surface 58 of the arm 46 is provided by
the downwardly directed portion of the recess, while the
second surface 60 is provided by the rear wall of the arm.
The lowèr portion of the recess provides a third surface 62
for engaging a corresponding third surface 64 formed on the
underside of the member 24 adjacent the hole, in the event of
an attempt being made to pull the arm 46 upwards while
upright. As the diameter of the arm is greater than the
horizontal spacing of the first and second surfaces 58, 60 of
the wall the picket cannot be moved from the hole, at least
while in a vertical orientation.
In practice, it has been found that the fence may be
assembled most easily if all of the pickets are first mounted
on the first transverse rail 16. A second rail 18 is then
located on the lower portio..s of the pickets by inclining the
rail 18 such that the first member 25 lies horizontally, as
illustrated in chain-dotted outline in Figure 6, and passing
the rail 18 over the arm 46 of the picket until adjacent the
lower recess 52. The rail is then rotated through
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approximately 45 such that the edges of the hole 33 engage
the recess 52 and the rear wall of the arm in a similar
manner to the upper hole 32 and first recess 50. It has been
found that the initial mounting of the rail 18 on the picket
is carried out more easily if the rail 18 is first located
over the ends of the pickets 20, 22 one at a time, as shown
in progress in Figure 7. Once the pickets 20, i2 are
positioned in the respective holes, the rail 18 is lifted to
adjacent the recesses and then rotated as described above.
The rail 18 is then attached to brackets 66, 68 extending
from the posts 12, 14 using suitable fastening means.
The embodiments of the inventions described above
are primarily intended for building fences on substantially
level ground. However, fences must often be located on
inclines. A further preferred embodiment of the present
invention is specially adapted for inclined sites and will
now be described with reference to Figures 8 and 9. A fully
assembled fence is shown in Figure 8, and it will be noted
that the appearance of the fence is similar to the fence
described above and as shown in Figure 1, apart from the
inclination of the transverse rails 76, 78. The support
posts 80, 82 and the pickets 84, 86 remain substantially
upright.
The construction of a fence conslsting solely of
rod-like pickets 84 may be achieved using the same apparatus
as was described with reference to Figure 1. The clearance
between the mounting locations of the transverse rails 76, 78
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and the plckets 84, more particularly the picket mounting
location of recesses, allows a degree of relative rotation
therebetween, sufficient to permit assembly of fences on an
incline such as illustrated in Figure 8.
Such a degree of movement between a transverse rail
and a picket is not, however, possible with the inverted
U-shaped pickets 22 described above. It is evident that to
accomodate an inclination of the transverse rails 76, 78 such
as is illustrated in Figure 8, that in addition to rotation
between the respective mounting location of the pickets 86
and the rails 76, 78 at least one of the arms of the picket
86 must be capable of moving vertically with respect to the
respective transverse rail. This movement cannot be
accomodated by the picket 22 described above. Accordingly,
each picket 86 is provided with mounting locations intended
to accomodate this movement.
Figure 9 shows a picket 86 having first and second
arms 88, 90. Conventional first and second mounting
locations or recess 92, 94 are provided on the first arm 88
in a similar manner to the picket 22. However the second arm
is provided with rectangular first and second mounting
locations or recesses 96, 98, one of which is illustrated in
more detail in Figure 10 of the drawings. The portion of the
second arm 90 illustrated in Figure 10 is shown in the
process of being located in a first member 100 of the first
transverse rail 76. Expressed functionally, the interaction
between the arm 90 and the hole edges involves engagement
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between oppos~ng flrst and second surfaces 102, 104 provided
by the holes edges and parallel and oppositely directed first
and second surfaces 106, 108 of the arm 90. The first
surface 106 is located on the front of the arm 90, in the
recess, while the second surface 108 is formed by the rear
wall of the arm.
The angle of inclination which may be accomodated by
the rail 76, 78 and pickets 86, is limited by the range of
rotation possible between the recesses 92, 94 of the first
arm 88 and the transverse rails 76, 78 and the height of the
recesses 96, 98 in the second arms 90, together with the
clearance between the arms 88, 90 and the hole edqes.
The method of assembly of the fence shown in Figure
8, is substantially similar to that of the fence illustrated
in Figure 1.
Reference is now made to Figure 11 of the drawings
which shows a side view of the picket 86, and illustrates a
preferred feature of the inverted U-shaped pickets. The
unrestrained picket 86 assumes a first configuration in which
the second arm 90 is substantially upright, while the first
arm is inclined.
When a fence is assembled using the pickets 86,
mounting the pickets 86 on the transverse rails 76, 78 forces
the arms 88, 90 to assume a second configuration in which the
arms are substantia~ly aligned. Reference is made briefly to
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F~gure 6 of the drawlngs, where line B illustrates the axis
of a typical unrestrained first arm, while line C is the axis
of the same arm in an assembled fence. This elastic
deformation of the picket results in an elastic tension
between the arm and causes them to tightly engage the
restraining surfaces of the respective holes in the
transverse rail and as a result of this, fences assembled
using such pickets are substantially "rattle free".
From the above description it may be seen that the
various aspects of the present invention provided a fence
construction which involves relatively few parts and a
minimal number of fasteninq means. The configuration of the
pickets and rails are also adapted for easy disassembly of
the parts.
Those skilled in the art will realize the various
modifications and improvements may be made to the examples of
the invention described above, without departing from the
scope and spirit of the invention. The transverse rails and
pickets are primarily intended to be manufactured of steel,
in the form of angle iron, though other suitable materials
may be used. Further, transverse rails of forms other than
the angle iron described above may be used to provide
suitable mounting locations.
