| 摘要 |
<p>A first member has pivot pins on opposite sides of the suction passage and a spring element projecting from at least one pin. A second member is assemblable around the first member and the pins to be pivoted on the latter, having detents with which the spring element can snap engage to hold the members adjustably in a selected one of several mutually pivoted positions. The or each spring element is moulded integrally with the associated pivot pin. Each pivot pin is moulded integrally with said first member. The or each spring element projects radially.</p> |
