摘要 |
<p>This invention provides a method of making an elastic air spring member and said member by forming a polyester preform (10), sometimes called a parison, blowing said preform to the shape of said member and at least shaping one end portion to give a surface (41) for sealing said member in the air spring device, said shaping usually being grinding or cutting away to give a sealing surface (41) although the neck (20) of the preform can be used to attach blown preform to the air line (14) and thus obviate the need to cut away a portion.</p> |