Plastics extruder with mixing head

摘要

765,209. Mixers for plastics extruding machines. EGAN & CO., F. W. Nov. 12, 1954 [Aug. 18, 1954], No. 32883/54. Class 86 [Also in Group V] A mixer D, mounted at the discharge end of the cylinder A of a plastics extruding machine of known type, comprises a casing 1 within which is located a drive pinion 16 extending axially from the end of the screw C of the machine, an internal gear 13 coaxial with the pinion 16 and locked to the casing by a pin 14, and a number of circumferentially-spaced mixing pinions 20 in mesh with said gear 13 and pinion 16. The feed and discharge ends of the pinion 20 are preferably of conical shape and in closelyspaced relation to frusto-conical surfaces of the inlet and outlet portions 5 and 6 of the mixing chamber which is defined by the casing 1 and a retainer ring 7, the latter being fitted with a coaxial breaker plate 9 held in position by a die 10; the discharge ends of the pinions 20 are also provided with shoulders 21 to abut the inner surface 22 of the ring 7. Electric heater bands 23, 24, 25 may be applied to the cylinder A, mixer casing 1 and die 10, and the extruding screw 6 may be provided with a cold-water circulating channel 26. In a modification (not shown) the mixing pinions 20 have longitudinallyspaced circumferential grooves, with thespacing of said grooves in certain pinions different from that in other pinions sothat at least portions of the teeth of one pinion extend into a groove of anotherpinion.