| 摘要 |
<p>The traction apparatus has a rigid plastics panel (1) with one flanged face (2). The panel has a figure of eight shape which is elongated and carries an elastic membrane (3) which defines to two air chambers. A central constriction communicates between the air chambers. One of the chambers has a coupling (4) with a passage extending through the panel for connection to an air supply tube. The supply tube is connected to a hand pump (5) with a check valve (6).</p> |
