| 摘要 |
<p>An apparatus for dipping spectacle frames in a colouring bath employes a very slow moving ram which raises and lowers the carrying frame. The ram piston slides in a cylinder divided into main and annular chambers. One of the latter (24, 25) is supplied with compressed gas so as to thrust the piston (20) against an incompressible liquid which fills the other chamber (25). The fluid escapes from this chamber via a port set to suit the desired piston travel speed, and means are included for returning the piston to the starting position on reaching its end position. The compressed gas or air can be delivered to the main chamber (24), while the fluid is contained in the annular one (25).</p> |
