| 摘要 |
1,177,652. Adjustable slot extrusion dies. GEVAERT-AGFA N.V. 7 March, 1967 [14 March, 1966], No. 11137/66. Headings B5A and B5B. [Also in Division F2H] An elongated slot-type die for extruding a sheet of thermoplastic material has at least one of its orifice lip members adjustably arranged for limited displacement relative to the other lip member, the adjustment mechanism controlling the displacement comprising a plurality of closely spaced adjustment screws extending longitudinally of the die, and which may both push and pull the adjustable lip member, the adjustment screws each comprising two parts of equal diameter and pitch in threaded engagement with aligned bores in the adjustable lip member and in the body portion of the die said two parts of each adjustment screw being in threaded engagement with each other through a screw threaded shaft portion of reduced diameter projecting from one part which engages a threaded bore into the other part, the pitch of the external threads of the parts being different from the threads through which both parts are engaged, and each of the two parts being arranged to receive a tool to rotate said part. In one embodiment Fig. 2 a die is composed of two parts 22 and 23 secured in mutual relationship by a bar 24 and bolts 25 and 26. An extrusion composition is fed through a channel 27 to a tear-drop manifold 28. A pair of lip members 30 and 31 form the extrusion orifice 29. The lip member 30 is made adjustable by the longitudinal region of locally weakened cross-section 32, and by transverse regions of weakened cross-section (not shown). Channels 34 and 35 contain heaters for controlling the temperature of the die. The adjustment of the lip member is controlled by adjustment screws 36, the upper part of which is in threaded engagement with the body portion of the part 22, and the lower portion of which is in threaded engagement with the portion of the part 22 below the region of weakened cross-section 32. In order to rotate the screws to adjust the orifice lip, a hexagonal key is inserted through bore 38 into a hexagonal socket formed in the upper part of the adjustment screw, and a second hexagonal screw is inserted through a bore 39 into a similar socket formed in the lower part of the adjustment screw. According to the direction of relative rotation of the screw parts the extrusion orifice width is increased or decreased. |
