| 摘要 |
<p>PURPOSE:To drastically improve airtightness in each guiding plate without sacrificing flexibility by providing an elastic tongue piece on each guiding plate. CONSTITUTION:On a lower guiding plate 12, elastic tongue pieces 12a, 12a are protrusively provided forward and backward, and the distance between each point is defined larger than a linking pitch of a link plate 11. On an upper guiding plate 13, elastic tongue pieces 13b, 13b are protrusively provided forward and backward, and the distance between each point is defined larger than that between each point of the tongue pieces 12a, 12a, while each tongue piece 13b is formed with its thickness at the point thinner than that at the root so as to promote the elasticity effectively. Each of its adjoining tongue piece 12a, 13b being overlapped each other and with elasticity, the guiding plates 12, 13 can contact each other elastically in bending, and airtightness is thus maintained without scarificing entire flexibility.</p> |
