WO2016200257A1

WO2016200257A1 - Tensioning strap for tubular objects

Info

Publication number: WO2016200257A1
Application number: PCT/NL2016/050411
Authority: WO
Inventors: Bauke Heeres
Original assignee: Lankhorst Engineered Products B.V.
Priority date: 2015-06-09
Filing date: 2016-06-09
Publication date: 2016-12-15
Also published as: NL2014939A; NL2014939B1

Abstract

A tensioning strap (1) for tubular objects comprises a strap (2) having a first loop end (11) and a second loop end (12), in which a first coupler (31) and a second coupler (32) are received, respectively. A tensioning bolt (4) is extending through a first passageway in the first coupler and through a second passageway in the second coupler. The first coupler comprises at opposite sides of the first passageway two respective first projections (51A, 51B), wherein each of the first projections, as seen in the sense of the first coupler longitudinal direction, projects at least with a radial direction component and at least with an axial direction component being directed towards the first passageway for embracing the first loop end. Thanks to the thus configured first projections the tensioning strap offers both during installing and during use effective safety. This makes this tensioning strap an interesting alternative for the known tensioning straps with double tensioning bolts, which are more expensive in their application.

Description

P108501PC00

Title: Tensioning strap for tubular objects.

The invention relates to a tensioning strap for tubular objects, such as tubes of various dimensions used in the oil and gas industry. More in particular the invention relates to a tensioning strap, which comprises a strap, having two loop ends, as well as a tensioning construction for interconnecting, in operation condition of the tensioning strap, the two loop ends under adjustable tensioning force of the tensioning strap.

Such tensioning straps are often used in the oil and gas industry among others to fasten all sorts of accessories to the outside of the tubular objects. The straps of such known tensioning straps are often made of fibre reinforced plastic material, and are often flexible and rather stiff.

One type of tensioning strap, known from practice, is shown in Fig. 1. It is a type of tensioning strap, of which the tensioning construction 103 has a single tensioning bolt 104. An important drawback of this known tensioning strap 101 is that this tensioning strap is unsafe. That is, one or more of the loop parts 111A, 11 IB, 112A, 112B of the strap 102 may shde-off sideways from the couplers 131, 132. This may for example happen during installing of the tensioning strap 101 around a tube, when the tensioning force of the tensioning strap still has to be adjusted for the intended operation condition of the tensioning strap. However, the loop parts 111A, 11 IB, 112A, 112B may also slide-off sideways from the couplers 131, 132 in case of an already installed tensioning strap, for example as a consequence of lost pre-tension of the strap 102 and/or in cases of sliding displacements of an accessory, which is fastened to the tube by the tensioning strap. Due to these events the strap 102 and the tensioning construction 103 may even get separated from one another, whereby they may fall off the tube, wherein also the accessory being fitted to the tube may fall-off from the tube. Falling of the parts 102 and/or 103 and/or accessories means danger, for example for persons who are standing under or near the tube. This is a serious safety risk of the known type of tensioning strap having a single tensioning bolt.

Said safety risk for the skilled person often is a reason for not using the known type of tensioning strap having a single tensioning bolt as shown in Fig. 1. Instead, the skilled person then chooses for another tensioning strap type, known from practice, of which an example is shown in Fig. 2. This is a type of tensioning strap 201 of which the tensioning construction 203 has two tensioning bolts 204A, 204B. It is clear that for this known tensioning strap 201 with double tensioning bolts, the two tensioning bolts are preventing the loop ends 211, 212 of the strap 202 from sliding-off sideways from the couplers 231, 232. Hence, in that sense this tensioning bolt 201 offers more safety.

However, also the application of the known tensioning strap type with double tensioning bolts has some drawbacks, especially in relation to the costs. Namely, the tensioning construction not only is more expensive as regards manufacturing costs, but also is more labour-intensive in installing, and, in addition, it is more susceptible to inaccuracies during installing. For example, the tightening of two tensioning bolts is more work than the tightening of one tensioning bolt. The occurrence of mutual differences in the tensioning forces of the two tensioning bolts may result into oneven load of the strap 202, which brings along an increased risk of breakage of the strap 202. But also the tensioning bolts and the couplers 231, 232 of the installed tensioning strap 201 may mutually slant due to the occurrence of mutual differences in the tensioning forces of the two tensioning bolts. The tensioning bolts 204A, 204B and the couplers 231, 232 suffer from this. Additionally, as a result of said slanting the loop ends 211, 212 may slide obliquely in the armpitlike angles between the tensioning bolts 204A, 204B and the couplers 231, 232, whereby the loop ends 211, 212 may get damaged. All together, the tensioning strap 201 therefore is less durable, which may lead to additional costs for replacement operations. It is noted that FR2943747A1 discloses a tensioning strap according to the pre-characterizing portion of the appended independent claim 1.

It is an object of the invention to provide a tensioning strap which can be applied safely and with low costs.

For that purpose, the invention provides a tensioning strap according to the appended independent claim 1. Specific embodiments of the invention are set forth in the appended dependent claims 2-4.

Hence, the invention provides a tensioning strap for tubular objects, comprising:

• a strap with a strap longitudinal direction, two opposite ends in the strap longitudinal direction, and two opposite longitudinal sides parallel to the strap longitudinal direction, wherein:

- one of the two opposite ends forms a first loop end of the strap in that the strap longitudinal direction at the first loop end is curved around a first loop axis direction of the first loop end, wherein said first loop axis direction is extending locally perpendicularly to the strap longitudinal direction,

- the other of the two opposite ends forms a second loop end of the strap in that the strap longitudinal direction at the second loop end is curved around a second loop axis direction of the second loop end, wherein said second loop axis direction is extending locally perpendicularly to the strap longitudinal direction,

- the strap along a part of the strap longitudinal direction has a first strap opening, which locally at the first loop end is extending centrally in-between the opposite longitudinal sides, and which divides the first loop end into two mutually parallel first loop portions, and

- the strap along a part of the strap longitudinal direction has a second strap opening, which locally at the second loop end is extending centrally in-between the opposite longitudinal sides, and which divides the second loop end into two mutually parallel second loop portions; and

• a tensioning construction for interconnecting, in operation condition of the tensioning strap, the first loop end and the second loop end of the strap under adjustable tensioning force of the tensioning strap, wherein:

- the tensioning construction comprises a first coupler having a first coupler longitudinal direction, a second coupler having a second coupler longitudinal direction, and a tensioning bolt having a tensioning bolt longitudinal direction,

- the first coupler has a first passageway having a first passageway direction, which is extending perpendicularly to the first coupler

longitudinal direction, and the second coupler has a second passageway having a second passageway direction, which is extending perpendicularly to the second coupler longitudinal direction; and

• wherein, as seen in said operation condition:

- the first coupler is extending with its first coupler longitudinal direction parallel to the first loop axis direction through the first loop end, and the second coupler is extending with its second coupler longitudinal direction parallel to the second loop axis direction through the second loop end,

- the tensioning bolt is extending, with its tensioning bolt longitudinal direction parallel to the first passageway direction and to the second passageway direction, through the first passageway and the second passageway,

- the tensioning bolt is extending through the first strap opening and the second strap opening,

- the two first loop portions, as seen in the first coupler longitudinal direction, are extending at opposite sides of the tensioning bolt, and the two second loop portions, as seen in the second coupler longitudinal direction, are extending at opposite sides of the tensioning bolt, and

- the tensioning bolt, the first coupler, and the second coupler are interconnected with tensioning bolt action for providing said adjustable tensioning force;

characterized in that

• the first coupler, as seen in the first coupler longitudinal direction, comprises at opposite sides of the first passageway two respective first projections, wherein each of the first projections, as seen in the sense of the first coupler longitudinal direction, protrudes at least with a radial direction component and at least with an axial direction component being directed towards the first passageway for embracing the first loop end in said operation condition.

Thanks to the first projections and thanks to said radial and axial direction components according to which these first projections protrude, the first coupler and the first loop end of the strap may, according to the invention, during installing of the tensioning strap be brought in a controlled safe manner in the mutual interlocking necessary for the operation condition. In fact said radial and axial direction components of the first projections provide an extremely effective and reliable interhooking of the first coupler and the first loop end of the strap. And also as long as during installing of the tensioning strap the tensioning construction does not yet provide tensioning force, for example because the tensioning bolt has not yet been mounted, said interhooking prevents that the first coupler falls out of the first loop end, especially if the strap is relatively stiff.

And in the installed operation condition the first projections moreover are co-operating extremely effectively with the mounted

tensioning bolt, whereby the first loop portions are locked up from all sides. Therefore the tensioning strap according to the invention offers effective safety not only during installing, but also during use. Furthermore this effective safety is offered by features being easy to realize in the form of only the first projections, which not only are already extremely effective on their own, but which also automatically provide to the tensioning bolt important synergistic added value. In fact the invention may therefore be realized by a tensioning strap with single tensioning bolt, which as regards manufacturing, installing and maintenance is cheaper than a tensioning strap with double tensioning bolts.

A preferable embodiment of a tensioning strap according to the invention has the features that, as seen in said operation condition, the shortest distance between the tensioning bolt, on the one hand, and the two first projections, on the other hand, as measured perpendicularly to the tensioning bolt longitudinal direction, at least is higher than or equal to 50% of the outer diameter of the shank of the tensioning bolt, and preferably higher than or equal to 75% of said outer diameter.

Such a minimum shortest distance between the tensioning bolt and the two first projections eases the interhooking of the first coupler and the first loop end for the purpose of installing the tensioning strap, especially if the strap of the tensioning strap is relatively stiff.

A further preferable embodiment of a tensioning strap according to the invention has the features that the second coupler (32), as seen in the second coupler longitudinal direction, comprises at opposite sides of the second passageway two respective second projections, wherein each of the second projections, as seen in the sense of the second coupler longitudinal direction, projects at least with a radial direction component and at least with an axial direction component being directed towards the second passageway for maintaining, in said operation condition, the positioning of the second coupler in the second loop end. Preferably, as seen in said operation condition, the shortest distance between the tensioning bolt, on the one hand, and the two second projections, on the other hand, as measured perpendicularly to the tensioning bolt longitudinal direction, at least is higher than or equal to 50% of the outer diameter of the shank of the tensioning bolt, and preferably higher than or equal to 75% of said outer diameter. Such second projections, and such a minimum shortest distance between the tensioning bolt and the two second projections, offer advantages which are analogous to the abovementioned advantages when applying the first projections.

In the following, the invention is further elucidated with reference to a non-limiting embodiment and with reference to the schematic figures in the attached drawing, in which the following is shown.

Fig. 1 shows in perspective view a tensioning strap with single tensioning bolt, known from practice.

Fig. 2 shows in perspective view a tensioning strap with double tensioning bolts, known from practice.

Fig. 3 shows in perspective view an example of an embodiment of an assembled tensioning strap according to the invention.

Fig. 4 shows an enlarged portion of the configuration of Fig. 3 in a somewhat different perspective view.

Fig. 5 separately shows the assembled tensioning construction of the tensioning strap of Fig. 3, in a transverse cross section in which the center lines of the tensioning bolt, the first coupler and the second coupler are extending.

Figs. 6, 7 and 8 show in side view three consecutive stages, respectively, of bringing the first coupler and the first loop end of the tensioning strap of Fig. 3 in mutual condition of interhookingly interlocking.

Figs. 9 and 10 show, in continuation of the stages of Figs. 6-8, the mounting of the tensioning bolt in the first coupler.

Figs. 11 and 12 illustrate that, after the mounting of the tensioning bolt as shown in Figs. 9 and 10, the first projections of the first coupler are co-operating extremely effectively with the mounted tensioning bolt to lock up the two first loop portions of the first loop end from all sides. The reference signs used in Figs. 3-12 are referring to the abovementioned parts and aspects of the invention, as well as to related parts and aspects, in the following manner.

1 tensioning strap

2 strap

3 tensioning construction

4 tensioning bolt

5 head of tensioning bolt 4

6 shank of tensioning bolt 4

7 check nut

8 shortest distance

9 washer

11 first loop end

11 A, 11B first loop portions

12 second loop end

12A, 12B second loop portions

20 strap longitudinal direction

21 first strap opening

22 second strap opening

31 first coupler

32 second coupler

40 tensioning bolt longitudinal direction

41 first passageway

42 second passageway

51A, 51B first projections

52 A, 52B second projections

71 first loop axis direction

72 second loop axis direction

81 first coupler longitudinal direction second coupler longitudinal direction

first passageway direction

second passageway direction Figs. 1 and 2, which show the two different tensioning straps 101 and 201 known from practice, have already been discussed in the

introduction hereinabove.

Figs. 3, 4 and 5 show the tensioning strap 1 according to the invention, including all parts and aspects listed above together with the corresponding reference signs.

As regards the tensioning bolt action it is noted that the shank 6 of the tensioning bolt 4 to a large extent is provided with outside screw thread, which co-operates with internal screw thread of the first passageway 41 through the first coupler 31. The second passageway 42 through the second coupler 32 does not have internal screw thread, while the part of the shank 6 of the tensioning bolt 4 which Figs. 3, 4 and 5 is extending through this second passageway 42 does not have outside screw thread. Furthermore, the shown check nut 7 has been applied in order to lock an adjusted tension condition. Also the shown washer 9 has been applied in order to prevent that the strap 2 could get damaged when adjusting the check nut 7.

As regards the abovementioned shortest distance between the tensioning bolt 4, on the one hand, and the two first projections 51A, 5 IB, on the other hand, and the abovementioned shortest distance between the tensioning bolt 4, on the one hand, and the two second projections 52A, 52B, on the other hand, it is noted that these two shortest distances in the shown example are equal to one another, and that therefore they have been indicated in Fig. 5 with the single reference numeral 8.

Reference is now made to Figs. 6, 7 and 8, which show three consecutive stages of bringing the first coupler 31 and the first loop end 11 of the strap 2 in mutual condition of interhookingly interlocking. As first stage Fig. 6 shows that the first coupler 31 with its first projection 51A is hooked about the first loop portion 11A.

As second stage Fig. 7 shows that the other first loop portion 1 IB is bent somewhat in the direction of the first loop portion 11A, and in that manner is passed between the two first projections 51A and 5 IB. This bending of the first loop portion 11B may for example be carried out by hand, for example by pressing the two first loop portions 11A and 11B towards one another. If the shortest distance 8 (see Fig. 5) between the tensioning bolt 4 and the two first projections 51 A, 5 IB at least is larger than or equal to 50% of the outer diameter of the shank 6 of the tensioning bolt 4, and more preferably larger than or equal to 75% of said outer diameter, this eases the action illustrated by Fig. 7, especially if the strap 2 is relatively stiff.

As third stage Fig. 8 shows that, next, the first coupler 31 with its first projection 5 IB is hooked about the first loop portion 11B. In the situation of Fig. 8 said radial and axial direction components of the first projections 51A and 5 IB are providing an extremely effective and reliable interhooking of the first coupler 31 and the first loop end 11 of the strap 2. In the situation of Fig. 8 said interhooking prevents that the first coupler 31 falls out of the first loop end 11, especially if the strap 2 is relatively stiff.

As continuation stages, Figs. 9 and 10 show the screwing of the first coupler 31 of the tensioning bolt 4 into the first passageway 41.

Figs. 11 and 12 illustrate that, after mounting the tensioning bolt, the first projections 51A, 5 IB of the first coupler 31 co-operate extremely effectively with the mounted tensioning bolt 4 in order to lock up the two first loop portions 11A, 11B of the first loop end 11 from all sides. Therefore, the tensioning strap 1 according to the invention offers effective safety not only during installation, but also during use.

It is noted that, in the shown example, the aspects regarding the mutual interhooking of the first loop end 11 and the first coupler 31, as elucidated by means of Figs. 6-12, hold in analogous manner for the mutual interhooking of the second loop end 12 and the second coupler 32.

It is further noted that, in the shown example, the projections 51 A, 5 IB, 52A, 52B at their free ends are rounded off to prevent damage of the strap 2.

It is further remarked that the abovementioned example does not limit the invention, and that various alternatives are possible within the scope of the appended claims.

For example, according to the invention the shortest distance between the tensioning bolt, on the one hand, and the two first projections, on the other hand, as measured perpendicularly to the tensioning bolt longitudinal direction, may also be smaller than 50% of the outer diameter of the shank of the tensioning bolt, till 0% of said outer diameter. Likewise, according to the invention the shortest distance between the tensioning bolt, on the one hand, and the two second projections, on the other hand, as measured perpendicularly to the tensioning bolt longitudinal direction, may also be smaller than 50% of the outer diameter of the shank of the

tensioning bolt, till 0% of said outer diameter. After all, if said shortest distances for example are equal to 0% of said outer diameter, there still exists, if the screw bolt has not yet been installed, space between the two first (or second) projections concerned for passing there-between the loop portions concerned.

Also the abovementioned shortest distance between the tensioning bolt and the two first projections according to the invention does not necessarily have to be equal to the abovementioned shortest distance between the tensioning bolt and the two second projections.

Furthermore, according to the invention, and as measured perpendicularly to the tensioning bolt longitudinal direction, the shortest distance between the tensioning bolt and one of the two first projections does not necessarily have to be equal to the shortest distance between the tensioning bolt and the other of the two first projections. Likewise, according to the invention, and as measured perpendicularly to the tensioning bolt longitudinal direction, the shortest distance between the tensioning bolt and one of the two second projections does not necessarily have to be equal to the shortest distance between the tensioning bolt and the other of the two second projections. In other words, according to the invention, the two respective first projections may protrude to mutually different extents with said axial direction component, and, according to the invention, also the two respective second projections may protrude to mutually different extents with said axial direction component.

Likewise, according to the invention the two respective first projections may protrude to mutually different extents with said radial direction component, and, according to the invention, also the two respective second projections may protrude to mutually different extents with said radial direction component.

However, other variations or modifications are also possible. These and similar alternatives are deemed to fall within the scope of the invention as defined in the appended claims.

Claims

1. Tensioning strap (1) for tubular objects, comprising:

• a strap (2) with a strap longitudinal direction (20), two opposite ends in the strap longitudinal direction, and two opposite longitudinal sides parallel to the strap longitudinal direction, wherein:

- one of the two opposite ends forms a first loop end (11) of the strap in that the strap longitudinal direction at the first loop end is curved around a first loop axis direction (71) of the first loop end, wherein said first loop axis direction (71) is extending locally perpendicularly to the strap longitudinal direction,

- the other of the two opposite ends forms a second loop end (12) of the strap in that the strap longitudinal direction at the second loop end is curved around a second loop axis direction (72) of the second loop end, wherein said second loop axis direction (72) is extending locally

perpendicularly to the strap longitudinal direction,

- the strap (2) along a part of the strap longitudinal direction (20) has a first strap opening (21), which locally at the first loop end (11) is extending centrally in-between the opposite longitudinal sides, and which divides the first loop end (11) into two mutually parallel first loop portions (11 A, 11B), and

- the strap (2) along a part of the strap longitudinal direction (20) has a second strap opening (22), which locally at the second loop end (12) is extending centrally in-between the opposite longitudinal sides, and which divides the second loop end (12) into two mutually parallel second loop portions (12A, 12B); and

· a tensioning construction (3) for interconnecting, in operation condition of the tensioning strap (1), the first loop end (11) and the second loop end (12) of the strap (2) under adjustable tensioning force of the tensioning strap, wherein:

- the tensioning construction (3) comprises a first coupler (31) having a first coupler longitudinal direction (81), a second coupler (32) having a second coupler longitudinal direction (82), and a tensioning bolt (4) having a tensioning bolt longitudinal direction (40),

- the first coupler (31) has a first passageway (41) having a first passageway direction (91), which is extending perpendicularly to the first coupler longitudinal direction (81), and the second coupler (32) has a second passageway (42) having a second passageway direction (92), which is extending perpendicularly to the second coupler longitudinal direction (82); and

• wherein, as seen in said operation condition:

- the first coupler (31) is extending with its first coupler

longitudinal direction (81) parallel to the first loop axis direction (71) through the first loop end (11), and the second coupler (32) is extending with its second coupler longitudinal direction (82) parallel to the second loop axis direction (72) through the second loop end (12),

- the tensioning bolt (4) is extending, with its tensioning bolt longitudinal direction (40) parallel to the first passageway direction (91) and to the second passageway direction (92), through the first passageway (41) and the second passageway (42),

- the tensioning bolt (4) is extending through the first strap opening (21) and the second strap opening (22),

- the two first loop portions (11A, 11B), as seen in the first coupler longitudinal direction (81), are extending at opposite sides of the tensioning bolt (4), and the two second loop portions (12A, 12B), as seen in the second coupler longitudinal direction (82), are extending at opposite sides of the tensioning bolt (4), and - the tensioning bolt (4), the first coupler (31), and the second coupler (32) are interconnected with tensioning bolt action for providing said adjustable tensioning force;

characterized in that

· the first coupler (31), as seen in the first coupler longitudinal direction (81), comprises at opposite sides of the first passageway (41) two respective first projections (51 A, 5 IB), wherein each of the first projections (51 A, 5 IB), as seen in the sense of the first coupler longitudinal direction (81), protrudes at least with a radial direction component and at least with an axial direction component being directed towards the first passageway (41) for embracing the first loop end (11) in said operation condition.

2. Tensioning strap according to claim 1, wherein, as seen in said operation condition, the shortest distance (8) between the tensioning bolt (4), on the one hand, and the two first projections (51A, 5 IB), on the other hand, as measured perpendicularly to the tensioning bolt longitudinal direction (40), at least is higher than or equal to 50% of the outer diameter of the shank (6) of the tensioning bolt, and preferably higher than or equal to 75% of said outer diameter.

3. Tensioning strap according to claim 1 or 2, wherein the second coupler (32), as seen in the second coupler longitudinal direction (82), comprises at opposite sides of the second passageway (42) two respective second projections (52A, 52B), and wherein each of the second projections, as seen in the sense of the second coupler longitudinal direction, projects at least with a radial direction component and at least with an axial direction component being directed towards the second passageway for maintaining, in said operation condition, the positioning of the second coupler in the second loop end (12).

4. Tensioning strap according to claim 3, wherein, as seen in said operation condition, the shortest distance (8) between the tensioning bolt (4), on the one hand, and the two second projections (52A, 52B), on the other hand, as measured perpendicularly to the tensioning bolt longitudinal direction (40), at least is higher than or equal to 50% of the outer diameter of the shank (6) of the tensioning bolt, and preferably higher than or equal to 75% of said outer diameter.