| 摘要 |
Vacuum sizing device has a modular construction consisting essentially of sets of pairs (32) of upper and lower sizing elements arranged end to end to define a passageway (26) having a cross-sectional shape and size corresp. to that required for a plastic extrusion (24) from a die (22). The elements are clamped between upper and lower backing members (20,30) held together by T-headed bolts (76). In order to maintain the extrusion (24) in close contact with the internal walls of the sizing elements, the walls are broken by strategically placed vacuum openings which merge within the element bodies and open into vacuum chambers. These chambers have screw threaded ports communicating with the exterior which can be connected to a vacuum source by couplings (50). The elements also contain cooling chambers through which a cooling fluid can be circulated for cooling the extrusion. The vacuum sizing device is for sizing extruded profiles such as PVC window frames. By using a modular structure, the mfg. costs of the device are considerably reduced as the element pairs are relatively small, identical pieces of metal which are ideally suited for computer controlled machine tool mfr. Also, the device can be dismantled and transported and cleaned with ease. |
