| 摘要 |
<p>Boomerang is pref. of dimensionally stable polypropylene. The from and back branches are connected in a rounded curve by a mid part. The upper face is curved from one edge to the other. The branches' axes make an angle >80 degrees but 90 degrees C. The edge of the front branch is higher than the back edge, at least at the crest, while a back edge of this rounded mid point is above front edge of this part, such that in each case there is a positive leading angle when viewed in a plane which is transverse relative to the boomerang's pivot axis.</p> |
