| 摘要 |
792,252. Filters. REED-PRENTICE CORPORATION. Nov. 18, 1955, No. 33108/55. Class 46. [Also in Group V] A filter 30, Fig. 2, is oscillatably and slidably disposed within a cylindrical chamber 20 which is secured to an extrusion barrel 10. Plastic material issues from the barrel, through an inlet 26 into chamber 20, through the filter and out through six apertures 28 in the chamber wall. The filter comprises a rigid member having a tubular part 32 and a cut-away portion 34 in which there are five rows of apertures 38, each row having six apertures. To the inside of the portion 34 is secured a flexible screen 40. When the filter is in the position shown in Fig. 3, plastic material passes through screen part 40<SP>1</SP>, through the uppermost row of apertures 38 and out through the apertures 28. When the screen part 40<SP>1</SP> is clogged, the operator turns the filter counterclockwise, by means of a handle 37, to position screen part 40<SP>11</SP> and the second row of apertures 38 opposite apertures 28 ; and so on, each row 38 being used in turn. For cleaning purposes the filter is pushed to the broken-line position shown in Fig. 1 by means of a fluidpressure cylinder 52 secured to chamber 20 by rods 56, in which position the screen is exposed and part 32 of the filter blocks the apertures 28. The device may be used for sampling the plastic material. Heaters 22 are secured to chamber 20.
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