[0001] The present invention refers to a safety fence of the type, incorporating a plurality
of posts, arranged at a mutual distance from each other and adapted to be mounted
substantially vertically in the ground or in another base, and at least two substantially
horizontal fence members attached to the posts, and preferably consisting of steel
ropes or wires.
[0002] Road fences of this kind are earlier known in different designs and they are often
positioned between the carriage ways of highways having carriage ways separated from
each other by a central reserve. Such road fences have been very successful and they
have actively contributed to a substantial reduction of accidents between opposing
vehicles on such roads.
[0003] Another big risk for accidents is vehicles travelling off the road towards the sides
thereof. In order to reduce the risk at such instants of accidents with vehicles travelling
off the road it has been put down large costs in removing trees, rocks and the like
along the roads, but this has not always proven itself to give the intended effect.
[0004] In order to prevent that a vehicle at incidents of accidents ends up outside the
carriage way, particularly at positions where there is a particular risk for subsequent
injuries, as for instance at water courses, areas with large level differences, etcetera,
it has also been arranged lateral road fences along particularly dangerous portions
of the road. Hereby it has primarily been used fences, which has earlier been developed
for the central reserve, the posts of which thereby as a rule have been arranged in
foundations directly adjacent the asphalt-paved carriage way, i.e. at the asphalt
edge or just outside this, in the so called supporting reserve.
[0005] This means that it has not been possible to use the supporting reserve between the
road embankment or the carriage way and the slope situated outside the supporting
reserve, e.g. by bicyclists, or by other slow-travelling vehicles, and neither as
a temporary parking area at engine failures or the like.
[0006] The purpose of the present invention now is to offer a side guard fence of the type
in question, which provides a solution of these problems, and this has been achieved
in that the side guard fence has been given the features defined in claim 1.
[0007] Another purpose of the invention is to provide a simple and reliable arrangement
for anchoring the horizontal members of the fence to the posts thereof and this has
been achieved with the features defined in claim 8 of the accompanying claims.
[0008] Hereinafter the invention will be further described with reference to embodiments
shown in the accompanying drawings.
Fig. 1 shows schematically in a partial cross section a post of a side guard fence
according to the invention, seen in a view in the longitudinal direction of a carriage
way, which also is shown only partly.
Fig. 2 is a diagrammatic perspective view of a portion of a side guard fence according
to the invention.
Fig. 3 shows in a view corresponding to Fig. 1, alternative positioning of the post
of the side guard fence with fence members supported by schematically shown retaining
members.
Fig. 4a shows a portion of a post equipped with a retaining member, as seen from the
side.
Fig. 4b is a front view of the post with a a retaining member and a horizontal fence
member supported therein.
Fig. 5a is a perspective view of a portion of a post with another type av retaining
member, and
Fig. 5b is a separate part incorporated in the retaining member according to Fig.
5a.
Fig. 6a is a perspective view of a portion of a post having a further type of retaining
member.
Fig. 6b is a separate part incorporated in the retaining member according to Fig.
6a.
Fig. 7a is a perspective view of a further post with another type of retaining member
according to the invention.
Fig. 7b illustrates a post with a retaining member according to Fig. 7a, as seen from
above.
Fig. 8a is a perspective view corresponding to Fig. 6a, showing a similar post but
having a slightly amended retaining member, and
Fig. 8b shows in perspective the retaining member used in Fig. 8a.
[0009] In Fig. 1 is schematically shown a portion av a paved, e.g. asphalt-paved carriage
way 1, which at its outer edge is bordered by an edge line 2 and outside this by a
supporting reserve 3, which still is substantially horizontal. Outside the supporting
reserve adjoins a slope 4, having an inclination, which partly is determined by the
terrain, but which preferably is 1:6 or bigger. In contrast to what has earlier been
used, a series of posts 5 (only one of which is visible in the drawing figure) has
been positioned outside the carriage way 1, as well as outside the supporting reserve
2, and they have instead been positioned in the slope 4 at a distance from the supporting
reserve, which distance is at most three metres. The post 5 is preferably anchored
directly in the ground material of the slope without use of pre-fabricated foundations
or foundations cast on site, and they can preferably be rammed down or positioned
in pre-made holes, whereby the portion 5a of the post anchored in the hole shall have
a depth of at least 60 centimetres.
[0010] The post 5 supports together with the other posts incorporated in the fence, a number
of substantially horizontally arranged fence members 6, in the embodiment shown 3
parts, which are positioned at mutually equal vertical distances, and which in the
embodiment illustrated can be made as steel ropes or wires, even if it also is possible
to imagine horizontal fence members in form of thin belts or rods.
[0011] In Fig. 2 is schematically shown in perspective a series of posts 5 of the type in
question, anchored in a slope 4 outside the supporting reserve 3 at a road and having
three horizontal fence members 6 arranged at substantially equal distances from each
other in vertical direction.
[0012] Fig. 3 shows in a view corresponding to Fig. 1 positioning of the post 5 at a certain
distance from the supporting reserve, whereby in the embodiment shown is used three
horizontal fence members 6, in equivalence with Fig. 1, whereas at a post 5' intimated
with dash and dot lines, which is positioned in the slope farther away from the supporting
reserve, it may be needed a larger number of horizontal fence members 6'. The mutual
distance between the adjacent strings 6' is just about the same as the distance between
the strings 6. In this manner it is ascertained that vehicles travelling off the road
at high speeds will be caught by means of the upper horizontal fence members, whereas
vehicles driving off at lower speed and/or at a low angle to the fence, will hit the
lower fence members.
[0013] Fig. 4a and 4b illustrate an appropriate type of retaining member for a horizontal
fence member 6, which here is illustrated as a steel rope. The retaining in this case
is constituted by an inclined slot 7, cut obliquely from above and downwards in the
wall of the post 5, which slot in Fig. 4a is shown from the side and in Fig. 4b from
the front, whereby a steel rope 6 is inserted in the slot 7, which in this perspective
is shaped almost as a horseshoe. Due to this design of the retaining member, a force
caused by a collision in the longitudinal direction of the rope will result in that
the rope 6 is retained due to the force component urging the rope against the wall
of the slot. At collision the car is caught by the horizontal fence members or the
steel ropes and when the car hits a post, this will be bent in the direction of travel
for the car and the steel ropes and the posts are separated from each other.
[0014] Fig. 5a and 5b illustrate another design of post and retaining members. In Fig. 5a
is shown a post 5 provided with a longitudinal slot 5a, and which has a number of
substantially keyhole shaped openings 8 situated above each other, and which pair
by pair serve to receive a cleat-formed hook 9, which has bigger portions 10 at its
ends. These bigger portions 10 have a size allowing them to pass through the upper,
wider part of each keyhole 8, whereas they after having been moved down in the more
narrow part of each keyhole opening, can not be pulled out of the openings 8. When
the fence is hit by a car these retaining members act in a manner corresponding to
the slot 7 according to Figs. 4a and 4b, whereby the forces acting perpendicularly
to the post cause the hook 9 and the walls of the holes 8 to be deformed thus that
their interconnection is interrupted.
[0015] It shall be observed that the post according to Fig. 4a and Fig. 5a have both been
shown with only one retaining member 7 and 8, 9 respectively, but in accordance with
what is earlier said, it is evident that each post has a number of retaining members
arranged in vertical direction, and which at least correspond to the number of horizontal
fence members 6, which are needed to be used in every individual case.
[0016] In Figs. 6a and 6b is shown an embodiment of a retaining member at a post 5, which
member is constituted by a number of slots 11 shaped as a reversed figure one, in
which is insertable a cleat-like hook 12, having ends 13 bent out in opposite directions.
[0017] At forces which act in the longitudinal direction of the fence members also in this
case the result will be that the fence members can move in relation to the retaining
members 11, 12 and to the posts, whereas forces generated when a car hits a post and
the post is bent in the direction of travel of the car, at the same time as the car
is caught by the horizontal fence members will result in that the ends 13 of the hook
or the walls of the hole 11 are deformed and the hook comes loose from the post.
[0018] In Figs. 7a and 7b is shown a further embodiment where the tubular post 5 has two
axially extending slots 14, where the horizontal fence members or steel ropes 6 are
positioned. The mutual distance between the steel ropes 6 is decided by spacer members
15, which are positioned in one or both slots.
[0019] Fig. 8a illustrates schematically a post 5 having the same type of holes 11 for retaining
members 12' as the post in Fig. 6a but the retaining members in this embodiment differ
slightly from those according to Fig. 6b.
[0020] When the horizontal fence members 6, in form of steel ropes are mounted in the retaining
members, these steel ropes are wound off from tractor-borne rollers on which very
long and therefore heavy strands of the rope are stored. With the hook member shown
in Fig. 6b, the rope must be wound of and positioned on the ground along the series
of posts, and then it is necessary for operators to walk along the fence to be, and
fit a hook member 12 around the rope 6 for every post and then to lift the rope up
to the hole 11 in the post with a substantial weight from the rope. This is a heavy
and tiring job, and it is also quite time-consuming, in view of the large number of
retaining positions.
[0021] The hook member 12' in the embodiment according to Fig. 8b, has a further bend 16
positioned adjacent one of its ends 13. With aid of this additional bend 16 it is
possible to position the retaining member or the hook 12' in the hole 11 in the post
5 such as shown in the lower hole 11 in Fig. 8a. With hooks 12' thus positioned in
all slots 11 in all posts 5 for a distance corresponding to the length of the steel
rope 6 on a storage roller, it is possible to lay the steel rope 6 directly in the
hook 12' such as shown in the upper position of the slot 11 in Fig. 8a. It might be
required some manual work in guiding the steel rope to come to rest in the hook member
12', but the heavy work for lifting the hooks with the weight of the steel rope is
eliminated. From the position shown in the upper part of Fig. 8a it is a comparatively
easy work to swing up the free end of the hook 12' and insert it in the upper part
of the slot 11 and thereupon to let it slide down until it is positioned in the same
manner as the retaining member 12, shown with dash and dot lines in Fig. 6a.
[0022] The invention is not limited to the embodiments illustrated in the accompanying drawing
figures and described with reference thereto, but modifications and variants are possible
within the scope of the accompanying claims.
1. Side guard fence of the type, which incorporates a plurality of posts (5) arranged
at a mutual distance along the edge of a carriage way and substantially being vertically
anchored, and substantially horizontal, longitudinal fence members (6) attached to
the posts and arranged at mutually spaced apart distances from each other in the vertical
direction,
characterized therein,
that the posts (5) are positioned in the slope (4) outside carriage way and supporting
reserve (3) if any.
2. Side guard fence as claimed in claim 1,
characterized therein,
that the inclination of the slope (4) is bigger or equal to 1:6.
3. Side guard fence as claimed in claim 1,
characterized therein,
that the posts (5) are mounted without foundations directly in the ground material
of the slope (4), by means of ramming or by lowering in holes intended therefore.
4. Side guard fence as claimed in anyone of the preceding claims,
characterized therein,
that the posts (5) have an anchoring depth in slope of at least 60 cm.
5. Side guard fence as claimed in anyone of the preceding claims, and where there are
more than two horizontal fence members (6),
characterized therein,
that the mutual distance between two adjacent horizontal fence members (6) attached
to the posts (5) is substantially equal and substantially constant.
6. Side guard fence as claimed in anyone of the preceding claims,
characterized therein,
that the fence has a varying number of horizontal fence members (6) in dependency
of the distance at which the posts (5) have to the carriage way (1).
7. Side guard fence as claimed in anyone of the preceding claims,
characterized therein,
that the horizontal members of the fence are constituted by steel ropes (6).
8. Side guard fence as claimed in anyone of the preceding claims,
characterized therein,
that the horizontal fence members (6) of the fence are anchored to the posts (5) by
means of retaining members (7;8;9;11,12;12';14) adapted to retain the horizontal fence
members (6) at forces caused by collision in the longitudinal direction of the fence
members, but to release the horizontal fence members (6) when acted upon by forces
generated at collision against a post (5).
9. Side guard fence as claimed in claim 8,
characterized therein,
that the retaining members are constituted by downwardly angled slots (7) provided
in the posts (5) in which slots the horizontal fence members (6) are received.
10. Side guard fence as claimed in claim 8,
characterized therein,
that the retaining members are constituted by hooks (9;12;12') inserted in slots (8;
11) in the posts, and through which hooks the horizontal fence members (6) are passed,
and which are adapted to come loose from the slots at collision forces, by deformation
of the hooks (9;12;12') and/or the edges of the slots (8;11).
11. Side guard fence as claimed in claim 10,
characterized therein,
that the hook (12') has two ends (13) bent in opposite directions, adapted to be positioned
inside the slots (11) in the mounted position of the hook, the hook (12') near one
of its ends (13) being provided with an additional bend (16) permitting the retaining
member (12') to be hung in the slot (11) with one end 13 outside the slot (11) during
positioning of the horizontal fence member (6) in the retaining member (12').
12. Side guard fence as claimed in claim 8,
characterized therein,
that the retaining members are constituted by substantially vertical slots (14) provided
in the posts (5), in which slots the horizontal fence members are received, and the
mutual distance between which is determined by spacing members (15) fitted in at least
one of said slots (14).