WO2012065611A1

WO2012065611A1 - A safety net for mounting in a wind turbine tower

Info

Publication number: WO2012065611A1
Application number: PCT/DK2011/000125
Authority: WO
Inventors: Cato Castro Christensen
Original assignee: Catonets Licens Aps
Priority date: 2010-11-17
Filing date: 2011-10-31
Publication date: 2012-05-24
Also published as: DK201600128U1; DK201600128Y4; EP2640912A4; EP2640912A1

Abstract

The invention relates to a safety net (100) for mounting in a wind turbine tower to existing screw bolts (220), front rail (240) and cable ladder (260) of the wind turbine tower, the wind turbine tower comprising at least two tower sections mounted together on a flange section (218) with the screw bolts (220), the safety net (100) defining a front edge (300) proximate to the wall of the wind turbine tower and the flange section (218) with the screw bolts (220), the safety net (100) defining a rear edge (400) proximate to a line defined by a diameter of the wind turbine tower, the safety net (100) comprising a profile (126) connected to the lower end (125) of the vertically mounted tube (120), the profile (126) being mountable to the front rail (240).

Description

A safety net for mounting in a wind turbine tower

The present invention relates to a safety net for mounting in a wind turbine tower to existing screw bolts, front rail and cable ladder of the wind turbine tower. The safety net in the present invention is used to keep workers positioned below the safety net into the wind turbine tower safe while inside a wind turbine tower undergoing construction or maintenance with possible falling down parts, such as loose tools or other parts typically being parts of the inside of a wind turbine tower.

BACKGROUND OF THE INVENTION

A wind turbine tower under maintenance or renovation is an inherently a dangerous environment for people working there. During construction or re- novations, it is important to protect the crew working inside the wind turbine tower from falling parts, such as tools.

The present invention provides a safety net to be installed into the tower of a wind turbine. Currently, net systems are available that may protect people on construction sites. However, such net systems suffer from several disadvantages. First, the prior art net systems are difficult to install because they are not suited to fit into the a tower of a wind turbine. Second, the prior art net systems are impossible to install properly into the tower of the wind turbine. To do so a lot of non-straight forward adaption of such nets would be required.

These are the limitations of the prior art that the present invention over- comes.

The document US 2006/0112532 discloses a security net with a metal bar. The document presents an invention, which provides an improved way to install a net around a loose or decaying object while at the same time keeping the net taut over time. The invention in US 2006/0112532 consists of a net constructed from fibers that shrink when moistened. This net is wrapped around the desired object and secured to a building by weaving a rope or metal bar through the net and attaching the rope or metal bar to the building with eyebolts, tie wraps, or lashing. The net is then moistened with water which causes it to shrink and fit tightly around the surface area of the object.

However this construction of a net from fibers that shrink when moistened makes it impossible to install it inside a tower of a wind turbine.

It is therefore an object of the present invention to provide a safety net, which can be installed inside the tower of a wind turbine to existing screw bolts, front rail and cable ladder of the wind turbine.

It is a further object of the present invention to provide a safety net that has all needed parts, so that the installation of the net is easy to perform inside the tower of a wind turbine.

The novel features that are considered characteristic of the invention are set forth with particularity in the appended claims. The invention itself, however, both as to its structure and its operation together with the additional ob- ject and advantages thereof will best be understood from the following description of the preferred embodiment of the present invention when read in conjunction with the accompanying drawings. Unless specifically noted, it is intended that the words and phrases in the specification and claims be given the ordinary and accustomed meaning to those of ordinary skill in the appli- cable art or arts. If any other meaning is intended, the specification will specifically state that a special meaning is being applied to a word or phrase.

Moreover, it is intended that the invention is not be limited only to the specific structure, material or acts that are described in the embodiments, but in addition, include any and all structures, materials or acts that perform the claimed function, along with any and all known or later developed equivalent structures, materials, or acts for performing the claimed features.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. .1 shows a perspective view of a part of the safety net seen from the rear edge with connections to screw bolts and a front rail.

FIG. 2 shows a perspective view of a part of the safety net seen from the rear edge with connections to screw bolts.

FIG. 3 shows a horizontally transverse tube. FIG. 4 shows another horizontally transverse tube. FIG. 5 shows a connection to a screw bolt.

FIG. 6 shows another connection to a screw bolt. FIG. 7 shows yet another connection to a screw bolt.

FIG. 8 shows a holder to a screw bolt. FIG. 9 shows a connection to a front rail. FIG. 10 shows another connection to a front rail.

FIG. 11 shows a vertical connection to a horizontal tube. FIG. 12 shows a vertical connection to two horizontal tubes.

FIG. 13 shows a two part connection from a vertical tube to a net.

FIG. .14 shows another two part connection from a vertical tube to a net. FIG. 15 shows how a net part is connected to a horizontal tube end.

FIG. 16 shows a top view of a part of the safety net with connections to a cable ladder. FIG. 17 shows a top perspective view of a part of the safety net with two connections to a cable ladder. DESCRIPTION OF PREFERRED EMBODIMENTS

The present invention is further described in more details with reference to the accompanying drawing, in which reference numerals with same numbers applied in the figures are intended to have the same meaning through the following description of the figures.

FIG.. 1 . shows a perspective view of a part of the safety net seen from the rear edge with connections to screw bolts and a front rail. The safety net 100 is intended to be mounted in a wind turbine tower to existing parts of the tower, i.e. to screw bolts 220, a front rail 240 and a cable ladder 260, see figure 17. The wind turbine tower in which the. invention is applied has at least two tower sections mounted together on a flange section 218 with the screw bolts 220. A wind turbine tower may have a cylindrical shape with e.g. a diameter of 4 or 5 meters.

The safety net 100 defines a front edge 300 being proximate to the wall of the wind turbine tower and the flange section 218 with the screw bolts 220.

The safety net 100 also defines a rear edge 400 proximate to a line defined by a diameter of the wind turbine tower.

The safety net 100 is made of a lot of parts, listed in their relation in the fol- lowing :

The net 105 itself also having the aforementioned front 300 and rear 400 edge^' 400. To support the net 105 at the rear edge 400 the safety net 100 is provided with a horizontally transverse tube 110 and a vertically mounted tube 120 - to the right in the figure - connected on its top 122 end to the horizontally transverse tube 110. The vertically mounted tube 120 is connected at a point distant from the wall of the wind turbine tower at the horizontally transverse tube 110. The vertically mounted tube 120 is intended to support a part of the net 105 it its location over a front rail 240 of the wind turbine tower, practically speaking a profile 126 is connected to a lower end of the vertically mounted tube 120, and the profile 126 is mounted onto the front rail 240, when the safety net 100 is installed inside the wind turbine tower.

Close to the end and opening of the horizontally transverse tube 110 proximate to the wall of the wind turbine tower, see to the left in the figure, is mounted another transverse tube 112. In an alternative embodiment of the invention the transverse tube 112 is mounted at the end and opening of the horizontally transverse tube 110 proximate to the wall of the wind turbine tower. Since the transverse connection is made of the tube 112 inserted into the tube 120, the transverse tube 112 is adjustable to various lengths in the horizontal direction. Hereby the transverse tube 112 - due to its ability to be adjusted to various lengths - can be positioned into wind turbine towers with varying shapes, e.g. different diameters of the tower of the wind turbine,

The safety net 100 is also provided with a number of straps 420. In an em- bodimeht of the invention the straps are elasticized straps. The straps 420 - in any case - are mounted between the rear 400 edge of the net 105 and the vertically mounted tube 120 and/or the transverse tube 112. Hereby one or both tubes 112 and 120 are supporting the net 105 since the net 105 is fastened thereto by the aforementioned straps 420.

At the left side of the safety net 100, i.e. at the end proximate to the wall of the wind turbine tower of the transverse tube, is mounted a vertically oriented two-piece holder 130, 132. This holder is also adjustable to various heights in the vertical direction of the holder 130, 132, since it is made of . two vertically mounted tubes 132 and 132, which can be displaced relatively to one another.

The lower end 131 of the mentioned above vertically oriented two-piece holder 130, 132 is adapted so that it 131 can be mounted on one of the screw bolts 220. This screw bolt carries the vertically oriented two-piece holder 130, 132, which in turn supports the left end of the transverse tube 112..

A further number of holders are applied to support and carry the net 105, that's why a number of holders, e.g. two holders, which are denoted 142 and 152, are positioned proximate to the wall of the wind turbine tower. These holders are adapted so that they can be mounted on their respective lower ends to two screw bolts 220, and they are also adapted so they on their upper ends can carry and support the net 105. In a practical realization, in other embodiments of the invention, the net 105 is provided with - at a position proximate to the wall of the wind turbine tower - with a number, e.g. two, three, four, etc vertically tubes 140 and 150. The two vertical tubes 140 and 150 as an embodiment of the invention are just an example of a . number of vertical tubes proximate to the wall of the wind turbine, which are mounted on their upper ends to the edge of the net 105. The two vertical tubes 140 and 150 are adapted on their respective lower ends to be mounted on the top of the two holders 142 and 152, which - when mounted to the two vertical tubes 140 and 150 - are adjustable to various heights in the vertical direction. This is possible since e.g. the tube 140 has a smaller diameter as that of the tube 142. Further, the tube 150 has a smaller di- ameter as that of the tube 150, which makes it possible for the tube 150 to slide in and out of the tube 152 in the vertical direction. The same functionality-applies for tube pair 140 and 142.

FIG. 2 shows a perspective view of a part of the safety net seen from the rear edge with connections to screw bolts. Behind the rear edge 400, i.e. proximate to the wall of the wind turbine two supporting telescopic pair of vertically oriented tubes 140, 142, 150 and 152 are mounted on top of two screw bolts. The two tops 140 and 150 of these two tube support the part of the net 105, which is proximate to the wall of the wind turbine. See figures 13 and. 14 for details as how the net 105 at these positions are tied to these , two tubes 140, 142, 150 and 152 at the front edge 300 of the net 105.

FIG. 3 ^'shows a horizontally transverse tube. The figure shows an embodiment of the horizontally positioned transverse tube 110, see also figure 1. The horizontally transverse tube 110 has an inner diameter of its hole, which makes it possible for the tube 112, see figure 1, to slide in and out of the horizontally transverse tube 110. In order to fix the horizontally transverse tube 110 to the tube 112 in a desired position it is provided with a wing screw 111. FIG. 4 shows another horizontally transverse tube. The figure shows an embodiment of the horizontally transverse tube 112, see also figure 1, which is implemented as tubular construction element in order to save weight in comparison to e.g. a rod, which is a massive element with a higher weight. FIG. 5 shows a connection to a screw bolt. The figure shows how the lower end 131 of an embodiment of the vertically oriented two-piece holder 130 is made so that it 131 can be mounted on one of the screw bolts 220. The diameter of its end hole 131 exactly fits over a hexagonal nut, and the length of its hole in the vertical direction matches the sum of the height of the nut and the length of threaded end of the screw bolt 220. As an example the screw bolts are 42 mm diameter, and the outer tube diameter of the lower end 131 of two-piece holder 130 is 60 mm.

FIG. 6 shows another connection to a screw bolt. The figure shows how the lower end 131 of another embodiment of the vertically oriented two-piece holder 130 is made so that it 131 can be mounted on one of the screw bolts 220. As opposed to the foregoing figure the diameter of its end hole 131 is larger and the diameter exactly fits around and over a bigger hexagonal nut, and the length of its hole in the vertical directions matches the sum of the height of the nut and the shorter length of threaded end of the screw bolt 220 as compared to the screw bolt in figure 5.

FIG. 7 shows yet another connection to a screw bolt. The figure shows how the embodiment of the holder 131 from figure 6 is positioned onto a screw bolt, which in the figure is covered completely by the lower end of the holder 131.

In three other embodiments of the invention the end profile of the lower part of the holder 131 of the figures 5, 6 and 7, the holder 131 is modified, i.e. it 131 is configured to exactly match and contact the six surfaces of a hexagonal nut when positioned over the nut, i.e. the profile is made similar to the profile of a box spanner or a socket wrench, which means that the profile has a hexagonal shaped opening which match the six surfaces of a corresponding hexagonal nut. FIG. 8 shows a holder to a screw bolt. The figure shows the embodiment of the holder 131 from figure 6 in its full length. In order to make it possible to assemble and fixate the top of the holder 131, the top of the body part 130 of the .holder is provided with a split pin 129. The split pin 129 makes it possible to fix another tube, e.g. the lower end of the tube 132, see figure 1 on the left hand side, into the hole at the top end of the tubular holder 130.

FIG. 9 shows an embodiment of a connection to a front rail. Since the net 105 need be supported by the front rail 240 inside the tower of the wind turbine, see figure 1, the lower 125 end of the vertical tube 120 is provided with a profile 126, which matches the shape of the upper part of the front rail 240. In the wind turbine tower the front rail 240 is protecting an elevator or a staircase positioned vertically inside the wind turbine tower.

FIG. 10 shows another connection to the front rail. The figure shows another embodiment of a connection to the front rail 240. The lower 125 end of the vertical tube 120 is provided with a profile 126, which matches the shape of the upper part of the front rail 240, and the top of the vertical tube 122 can be connected to the horizontal tube 110, see figure 1. The two split pins 129 make it possible to mount two other tubes at the sides of the T shaped tubu- lar element 122.

FIG. 11 shows a vertical connection to a horizontal tube. The figure - along with Fig. 1 - show- how the left end of the horizontal tube 112 is mounted into a hole of the vertical tube 132. In order to securely fix the left end of the horizontal tube 112 to the top of the vertical tube 132 a screw 134 is provided.

FIG. 12 shows a vertical connection to two horizontal tubes, i.e. the tubes 110 and 115 of Fig. 1. The tubular vertical connection element 124 is also shown in Fig. 1. Due to the V-shaped top of the tubular vertical connection element 124, it provides for that the horizontally construction, i.e. is the tubes 112, 110 and 115 can me mounted in an angle, which is determined by the angle.determined by the mentioned V-shaped top profile.

FIG. 13 shows a two part connection from a vertical tube to a net. The figure shows how the two tubes 140 and 142 are connected to one another in that the lower end of the tube 140 can be mounted vertically into the top end of the tube 142. Further the figure shows how an edge of the net 105, e.g. a rope of the net 105 is connected into a horizontal oriented hole in the upper end of the tube 140. The two tubes 140 and 142 are also shown in Fig. 1 and Fig. 2.

FIG. 14 shows another two part connection from a vertical tube to a net. As in the foregoing figure, figure 14 shows how the two tubes 150 and 152 are connected to one another in that the lower end of the tube 150 can be mounted vertically into the upper end of the tube 152. Another edge of the net 1.05, e.g. a rope of the net 105 is connected into a horizontal oriented hole in the upper end of the tube 150. The pair of tubes 140 and 152 is also shown in Fig. 1 and 2. FIG. 15 shows how a net part is connected to a horizontal tube end. The horizontal tube 115, which is supported by the tubes 122 and 120, has a rope around its right end, and the robe is mounted to the net 105. The rope forms an eyelet, which matches the diameter of the right end of the tube 115, however only the left end of the tube 115 is seen in Fig. 1.

FIG. 16 shows a top view of a part of the safety net with connections to a cable ladder. The cable ladder, denoted 260 in Fig. 17, carries and supports cables 108 which are needed for power control and power generation from and/to the generator of a wind turbine. A part of the net 105 is also sup- ported by the cable ladder 260, see Fig. 17 for more details and explanation.

FIG. 17 shows a top perspective view of a part of the safety net with two connections to a cable ladder. A part of the net 105 is supported by the cable ladder 260 by means of two expansion bolts 106 mounted into two op- posite sides of the cable ladder 260. Into each of the eye lets 104 of the two expansions bolts 106 is mounted a snap hook 103. In order to support and carry a part of the net 105 proximate to the cable ladder 260, the net 105 is mounted in this position - on two opposite parts - to the two snap hooks 103. The embodiments of the invention are described above in the figures and in the description of the embodiments. While these descriptions directly describe^" the above embodiments, it is understood that those skilled in the art may conceive modifications and/or variations to the specific embodiments shown and described herein.

Any such modifications or variations that fall within the purview of this description are intended to be included therein as well. Unless specifically noted, it is the intention of the inventor that the words and phrases in the specification and claims be given the ordinary and accustomed meanings to those of ordinary skill in the applicable art(s).

The foregoing description of embodiments of the invention known to the applicant and inventor at the time of filing the application has been presented and is intended for the purposes of illustration and description.

It is not intended to be exhaustive or to limit the invention to the precise form disclosed, and many modifications and variations are possible in the light of the above teachings. The embodirhents were chosen and described in order to best explain the principles of the invention and its practical application and to enable others skilled in the art to best utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated.

Claims

A safety net ( 100) for mounting in a wind turbine tower to existing screw bolts (220), front rail (240) and cable ladder (260) of the wind turbine tower, the wind turbine tower comprising at least two tower sections mounted together on a flange section (218) with the screw bolts (220), the safety net (100) defining a front edge (300) proximate to the wall of the wind turbine tower and the flange section (218) with the screw bolts (220), the safety net (100) defining a rear edge (400) proximate to a line defined by a diameter of the wind turbine tower, the safety net (100) comprising : a net (105) having the front edge (300) and the rear edge (400), a horizontally transverse tube (110) at the rear edge (400) of the net (105) and a vertically mounted tube (120) connected at its top (122) end close to the horizontally transverse tube (110) at a point distant from the wall of the wind turbine tower, a profile (126) connected to the lower end (125) of the vertically mounted tube (120), the profile (126) being mountable to the front rail (240), at the end and opening of the horizontally transverse tube (110) proximate to the wall of the wind turbine tower being mounted a transverse tube (112) adjustable to various lengths, a number of mounting means (420) mounted between the rear (400) edge of the net (105) and the vertically mounted tube (120) and/or the transverse tubes (112), at the end proximate to the wall of the wind turbine tower of the transverse tube (112) being mounted a vertically oriented two-piece holder (130, 132) adjustable to various heights of the holder (130, 132), a lower end (131) of the vertically oriented two-piece holder (130, 132) .^'being adapted so that it can be mounted on one of the screw bolts (220), . a first number of holders (142, 152) proximate to the wall of the wind turbine tower being adapted so that they can be mounted on their respective lower ends to a corresponding number of screw bolts (220), and the net (105) comprises proximate to the wall of the wind turbine tower a corresponding first number of vertically tubes (140, 150) mounted on their upper ends to an edge of the net (105), the first number of vertically tubes (140, 150) being adapted on their lower ends to be mounted on the top of the first number of holders (142, 152) which together with the first number of vertically mounted tubes (140, 150) are being adjustable to various heights.

2. The safety net (100) according to claim 1 comprising two expansion bolts (106) mounted between two opposite parts of the net (105) at the front edge (300) of the net (105) and two opposite points of the cable ladder (260).

3. The safety net (100) according to claim 1, the mounting means (420) comprises a number of elasticized straps (420).