| 摘要 |
The pair extending parts (2) form an angle with each other and are fixed to the support part (1). The support part width is at most 50 per cent of the distance between the outer ends (3) in the same pair of the extending parts. The extending parts are arranged at a distance from each other along the support part. The plane through the extending parts forms an angle with the support part longitudinal direction which is less than 90 deg. |
