The invention relates to a mast arrangement comprising at least two single masts and at least one beam connecting the single masts.
Medium-voltage and low-voltage networks use wooden pole arrangements which carry crossbeams to which transmission lines are attached. The crossbeams are usually steel tubes or I-beams made of steel or wood which are connected to the wooden pole arrangement via angled U profiles, said U profiles being attached by hooks to the upper end of the wooden pole arrangement. One of the possible wooden pole constructions is known as an H mast which usually consists of two single masts and a bracing connecting them.
A fundamental disadvantage of the known wooden pole constructions is that they cannot be calculated statically in a sufficiently accurate manner. A basic reason for this is that wooden poles expand to different extents due to changes in the ambient temperature and environmental moisture, For this reason, the configuration of wooden poles in respect of their thickness as well as the size and type of the connecting elements is based on empirical experimental values with the disadvantage that the designs used are uneconomical.
In contrast thereto, the object of the invention is to provide a mast arrangement of the type mentioned at the outset which can be calculated statically and can be configured appropriately for the load at a low cost.
This object is achieved by a mast arrangement having the features of claim Preferred embodiments of the invention are set out in the sub-claims.
The term “beam” as used here and in the following is understood as meaning any mast element which has the effect of connecting the single masts and has the action of a supporting structural beam or bar.
The term “composite anchor” as used here and in the following is understood as meaning a connecting element with a core which carries a plurality of anchor pins, The core can have a symmetrical or asymmetrical shape. Oblong cores with a square or rhomboidal cross section have proved to be relevant in practical terms. However, cores configured as polyhedra or other symmetrically or asymmetrically configured cores can also be used.
The composite anchors can be configured with one or more through holes, as required, along or transversely through their core and can serve as so-called through anchors as bearings for set screws, They can also have tapped holes for screws which are to be attached to the anchor.
Depending on the field of use, the anchor pins can extend parallel to one another towards one side only or on opposite sides of the core in opposite directions. A composite anchor can also be a joint connection for two or more beams with at least two anchor pin regions acting in different directions, particularly when the core is a polyhedron. The anchor pins can have a round or polygonal cross section and can be configured in particular as pegs. The anchor pins can be configured in one or more parts from the same or different materials. Conical anchor pins which taper in a direction remote from the anchor core are particularly preferred.
It has surprisingly been found that when composite anchors provided with anchor pins are used as connecting elements, both tensile and compressive forces as well as the pushing or shearing forces which arise between the beams and single masts to be connected are transmitted in a particularly effective manner, since the anchor pins do not transmit the forces to the outer side of a beam or of a single mast but introduce said forces inside said beam or single mast. Consequently, the introduction of force largely is largely independent of the geometric dimension of the beam or of the single mast. Therefore, the mast arrangement according to the invention can be calculated statically for the first time in such an accurate manner that the choice of materials used and the material thicknesses can be determined for the first time based on calculations for the loading conditions which are to be expected.
The materials for beams, single masts and composite anchors can be selected such that the composite anchor can be pressed into the outer surface of the beam and/or single masts. This is particularly possible when the mast has in the region of the anchor seat a rubbery material which has resilient characteristics within specific limits. In particular, when the anchor pins have one or more undercuts such that the encircling edges of the anchor pin which are formed by the undercuts press into the surface of a seat produced by the pressing-in action, the composite anchor can sit firmly in the seat.
However, particularly in the case of beams or single masts made of wood, recesses are preferably provided in the outer surface thereof which furthermore preferably correspond to the shape of the anchor pins before said anchor pins of the composite anchor are inserted into the seats in the outer surface of the beam.
In a further preferred embodiment of the mast arrangement according to the invention, means are provided for securing the composite anchor which engages into the seats in the outer surface(s) of the beam(s) and/or single masts. Means of this type include in particular mechanical attachment means, particularly screws or screw bolts which engage for example directly into the beam, whether this is parallel to the anchor pins or obliquely thereto, the attachment means preferably being directly connected to the composite anchor. Suitable adhesives, for example two-component adhesives, are also included as fasteners.
Other attachment possibilities consist, for example, in securing the composite anchor to the beam or single mast by a clamp which engages around the composite anchor and the beam or single mast. Furthermore, the composite anchor can be directly positioned between a beam and a single mast, it then being possible for the beam and mast to be held together by further attachment means such as screws, clamps or the like, such that the composite anchor is held securely in its position between the beam and the single mast.
In particular in the case of two beams, but also where there is a plurality of beams which rest against a single mast and against one another, the opportunity is presented for the composite anchor to be provided with anchor pins for the single mast and also for each of the beams and for the composite anchor to engage with said anchor pins into the single mast and into the beams in order to achieve as effective a transmission of forces as possible from the beams into the single mast as well as from beam to beam.
However, embodiments are likewise preferred in which the composite anchor only has anchor pins for a single mast or beam and is connected to the beam or single mast to be connected in each case by other means. Thus, a composite anchor which engages in a single mast on one side with anchor pins and is attached to the mast, for example by a screw connection, can be connected on the other side to a U profile carrying a crossbeam, for example by riveting, by a welded connection and/or a screw connection.
When the beams which are joined together by a composite anchor at least partly rest against one another, it is advantageous for said beams to be planar in their mutually contacting regions. In particular when the mast arrangements are only produced at the site where they are to be erected, it is substantially easier to create a planar installation surface than it is to provide a profiled surface.
A mast arrangement according to the invention can optionally be provided with a crossbeam which can likewise be connected as a beam to the mast arrangement by one or more composite anchors. The mast arrangement can be reinforced by at least two crosswise arranged beams, said beams preferably being interconnected at the point of intersection by an interlying composite anchor.
The mast arrangement according to the invention is particularly suitable for single masts and beams made of wood or a composite wood material and is particularly suitable for mast arrangements with single masts made of round wood. It is precisely when natural materials are used that the advantage of calculability becomes particularly significant, especially when composite anchors are used as connecting elements at all the force transmission points between the single masts and beams. However, the beams and the single masts can likewise also be made for example of a plastics material, a concrete material or other suitable materials.
The mast arrangements according to the invention are particularly suitable for use as poles in medium-voltage, low-voltage and high-voltage networks up to 360 kV, but can also be used in telecommunications networks, for example telephone poles.
In the following, the invention will be described in more detail with reference to figures which show various preferred embodiments of the invention.
a is an isometric illustration of a composite anchor which can be used for the mast arrangements according to the invention and which has a curved, continuous anchor surface;
b is a plan view of the composite anchor shown in
c is a cross-sectional view of the composite anchor shown in
d is a longitudinal sectional view of the composite anchor shown in
The mast arrangement shown in
In an upper portion, the mast arrangement has a horizontal beam as a crossbeam 9 which is attached to both single masts 1, 2 and extends at both ends beyond the single masts. The means 11, 12 for attaching the crossbeam 9 to the single masts 1, 2 will be described below with reference to
While the beams 3, 4 as well as the crossbeam 9 are configured as squared timbers, the single masts 1, 2 consist of round timbers.
The mast arrangement shown in
In its upper portion, the mast arrangement supports a horizontal crossbeam 28 formed by two parallel squared timbers 29, 31 which are attached to opposing ends of the single masts 21, 22. The attachment of the squared timbers to the single masts will be described in detail further below with reference to
Connecting blocks 32, 33, 34 are arranged between the squared timbers 29, 31 at their outer front ends and in the centre of the crossbeam 28. Attached to the two outer connecting blocks 32, 34 is in each case a rod-like beam 35, 36 which extends at an angle of approximately 45° and which is connected to a respective single mast 21, 22 at its ends remote from the connecting blocks, The centre connecting block 33 is connected to two beams 37, 38 which extend upwards in each case at an angle of 45° to the crossbeam 28 and the ends of which, remote from the connecting block 33, are each connected to one of the two single masts 21, 22. The attachment of the beams 35, 36, 37, 38 to the connecting blocks 32, 33, 34 will be described in detail with reference to
Metal sheets 54, 55 as surface protection are tightly screwed onto the squared timbers 29, 31 in the attachment region on their sides facing the composite anchors. The squared timbers 29, 31 are then attached with two screws 56, 57 in each case to the anchor cores. If U profiles, made of metal for example, are used for the crossbeams instead of squared timbers, the metal sheets 54, 55 will not be required.
The connecting block 33 arranged between the squared timbers 29, 31 is a cuboid having a rectangular cross section. Along its longitudinal axis, it has a slot and is attached between the squared timbers 29, 31 by a screw bolt 63. Respective through holes are also provided parallel to the two short centre axes of the connecting block 33. It is thus possible to attach the beams 36, 37 to the connecting block 33 and thus to the crossbeam 28 by screw bolts 64, 65 which are guided through the through holes and screwed into the composite anchors 61, 62.
The connection of the beam 35 to the crossbeam 28 shown in
The anchor pins of the composite anchor 74 are introduced into the recesses in the single mast, The composite anchor 74 is then attached to the single mast by screws 75.
A hinge element 77 is held in the recess 76 in the composite anchor 75 by a bolt 78 guided through the slot. The hinge element has a web directed towards the end of the beam 72.
The composite anchor 73 is coupled with composite anchor 75 by a screw bolt 79 which is screwed into the composite anchor 73 and the head of which is also provided with an eye. The eyes in the head of the bolt and in the hinge element 77 are then connected together by a pin 81.
The composite anchor shown in
The semi-circular body of the anchor core does not extend over the entire length of the composite anchor. Instead, it has two spaced apart, but mutually aligning anchor parts 151, 151′. The interruption in the anchor body serves as a seat for the previously described hinge element which is held by a bolt inserted into the slot 157, 157′.
Number | Date | Country | Kind |
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10 2007 033 829.7 | Jul 2007 | DE | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/EP2008/059365 | 7/17/2008 | WO | 00 | 3/10/2010 |