The invention relates to a fixing structure according to claim 1 and to a mounting assembly using the same

The document JP 3391432 B2 discloses a fixing structure to fix and support a fuel tank while allowing for an expansion the fuel tank . Fixed bands are respectively fastened to mounting support parts of a pair of supporting frames in front and in rear fixed to a body and both j ointing ends facing the fixed bands provided on the outer circumference of the fuel tank are connected together through a spring .

The document CA 2290259 Al discloses a restraining strap for pressure vessels including V-bends , wherein strap elastically shortens and lengthens while each V-bend flexes within the elastic range and providing a consistent vessel holding force .

The invention is based on the problem of providing a simple and robust fixing structure having a sufficient elasticity to accommodate possible expansions of the cylindrical obj ect being fixed, in particular a high-pressure fuel tank .

The problem is solved by a device having the features of claim 1 . Advantageous embodiments of the invention are defined in the dependent claims .

The invention relates to a fixing structure including a band for fixing a cylindrical item and a tightening device connecting two band ends of the band and being configured to tighten the band by approaching the band ends , wherein at least one of the band ends forms a loop provided with an opening at the apex thereof the tightening device includes a metallic trunnion arranged in the loop and a tensioning bolt attached to the trunnion and extending through the opening .

The band is preferably a steel band, but other strong materials are possible . The tightening device may be formed as a tighten- ing screw or as a lever-type tightening device including an eccentric lever . The opening at the apex of the loop of the first band end is generally provided so as to face the second band end and the opening is preferably a longitudinal slit allowing for a swivelling of the tensioning bolt and preferably extending to a rear side of the loop so as to allow the insertion of a tool into a head of the tensioning bolt .

It is proposed that a polymer body is provided between the trunnion and an inner surface of the loop . The polymer body lends a sufficient degree of elasticity to the fixing structure , in particular when being applied for fixing high-pressure fuel tanks in vehicles .

The metallic trunnion has a longitudinal direction extending perpendicular to the longitudinal direction of the band and parallel to the width direction of the band and has a length exceeding a width of the opening , wherein the length of the trunnion preferably corresponds to the width of the band .

In a preferred embodiment of the invention, the polymer body has an essentially cylindrical outer shape including a radially outer surface configured to abut to the inner surface of the loop, a central bore configured to receive the metallic trunnion and openings in the radially outer surface configured to insert and receive the tensioning bolt .

The inventors further propose that the band is provided with a rubber liner 22 on an inner side thereof .

In a preferred embodiment of the invention, both of the band ends form a loop each loop receiving a trunnion, wherein one of the trunnions is provided with an inner thread engaging with an outer thread of the tensioning bolt .

A further aspect of the invention Mounting assembly for mounting a hydrogen tank in a vehicle , wherein the hydrogen tank is fixed with a fixing structure according to one of the preceding claims , the hydrogen tank being the cylindrical item.

Further features and advantages will be apparent from the following description of the embodiments and figures . The entire description, claims and figures disclose features of the invention in specific embodiments and combinations . The person s killed in the art will also consider the features individually and combine them into further combinations or sub-combinations to adapt the invention, as defined in the claims , to his needs or to specific fields of application .

The figures illustrate the following :

Fig . 1 a fixing structure according to the invention, and Fig . 2 a detailed view of the polymer body of the fixing structure .

Fig . 1 shows a first embodiment of the invention .

The fixing structure according to the invention includes a band 10 for fixing a cylindrical item such as a hydrogen tank in a vehicle and a tightening device connecting two band ends 12 , 14 of the band 10 and being configured to tighten the band 10 by approaching the band ends 12 , 14 . The band 10 is provided with a rubber liner 22 on an inner side thereof to provide some further elasticity and grip .

Both of the band ends 12 , 14 form a loop each loop receiving a trunnion 18 , 20 wherein one of the trunnions 20 is a threaded trunnion 20 and is provided with an inner thread engaging with an outer thread of the tensioning bolt 24 and the other one of the trunnions 18 is an unthreaded trunnion 18 having a bore for inserting the tensioning bolt 24 .

Both of the loops are provided with an opening 26 , 28 at the apex thereof . The tightening device includes the unthreaded trunnion 18 , which is a metallic trunnion 18 arranged in one of the loops and the tensioning bolt 24 attached to the trunnion 18 and extending through the openings 26 , 28 in both of the loops and engaging with the thread of the threaded trunnion 20 .

The opening 26 at the apex of the loop of the first band end 12 is provided so as to face the second band end 14 and vice versa . At least the opening 26 of the loop receiving the unthreaded trunnion 18 is preferably a longitudinal slit allowing for a swivelling of the tensioning bolt 24 and preferably extending to a rear side of the loop so as to allow the insertion of the tensioning bolt 24 from the rear side and the insertion of a tool into a head of the tensioning bolt 24 .

The loops are formed by folding the end of the band 10 back onto itself and clinching , welding or otherwise fixing the band end, wherein the first loop on the first band end 12 has a larger curvature radius and length than the loop on the second band and 14 to account for the larger radius of the polymer body 16 described later .

The metallic trunnion 18 is a cylindrical body with a length corresponding to the width of the band 10 and with a radius which is smaller than the radius of curvature of the first loop at its apex, preferably at least 30% smaller, so as to provide radial space for the polymer body 16 to be described in more detail below . A bore oriented in a direction transversal to the longitudinal direction of the trunnion 18 is provided in the axial centre thereof to accommodate the tensioning bolt 24 .

The tensioning bolt 24 is a screw with an outer thread at its end potion and with a head having a diameter larger than the diameter of the bore and having a hexagonal socket .

According to the invention, the polymer body 16 is provided in a radial space between the trunnion 18 and an inner surface of the loop . The polymer body 16 lends a sufficient degree of elasticity to the fixing structure , in particular when being applied for fixing high-pressure fuel tanks in vehicles . Fig . 2 illustrates the polymer body 16 in a detailed view . The polymer body 16 has an essentially cylindrical outer shape including a radially outer surface configured to abut to the inner surface of the loop, a central space 16a configured to receive the metallic trunnion 18 and openings 16b , 16c in the radially outer surface configured to insert and receive the tensioning bolt 24 .

One of the openings 16c is configured to face the apex of the loop when the polymer body 16 is in its configuration for use and has a diameter substantially equal to the diameter of the tightening bolt to allow the insertion thereof . The opening 16b on the opposite side of the polymer body 16 extends over the entire length thereof and allows for the insertion of the trunnion 18 from the side thereof and is a slit forming the space 16a for the trunnion 18 . The trunnion 18 and the polymer body 16 may be pre-assembled to form a composite trunnion 18 including a metal core and a polymer j acket . In further embodiments of the invention ( not illustrated) , the polymer body 16 may be moulded onto the trunnion 18 .

For assembly, the trunnion 18 is inserted into the polymer body 16 , the polymer body 16 with the trunnion 18 is inserted into the loop from one of its lateral sides and then the tightening bolt is inserted into the openings 26 , 16b, 16c , 28 of the band ends 12 , 14 , the polymer body 16 and trunnion 18 so as to engage with the inner thread of the threaded trunnion 20 on the other end 14 of the band 10 .

The fixing structure of Figures 1 and 2 is part of a mounting assembly for mounting a hydrogen tank in a vehicle , wherein the hydrogen tank is fixed with a fixing structure as described above , the hydrogen tank being a cylindrical item . List of reference numbers

10 band 12 band end

14 band end

16 polymer body

18 trunnion

20 threaded trunnion 22 liner

24 tensioning bolt

26 opening