| 摘要 |
693,153. Extrusion machines for rubber &c. PIRELLI SOC. PER AZIONI. Sept. 20, 1951 [Jan. 12, 1951; June 9, 1951], No. 22098/51. Class 87 (ii) [Also in Group II] A machine comprises a jacketed tubular chamber through which the material is forced, a rotor within the chamber having screw threaded feed ing, working and extrusion sections, the shank which carries the screw thread of the working section being of helical form, the material being worked between the. helical shank and the wall of the chamber as it passes through the channel defined by the screw thread. In Figs. 1 and 2 the rotor comprises feeding and extrusion sections 12, 13 having single threads which are continuous with a thread 15 on a single-helix helical shank 16 of the working section 14. The linear trace of a point on the shank 16 lying at the greatest radius from the rotor axis is shown by the line 19, Fig. 2, and has the form of a helical ridge spaced a short distance 21 from the surface of the mixing chamber. In operation material travels towards the left through the helical channel defined by the thread 15 and is forced over the ridge 19 from an element 17 of the helical channel on the left hand side of the ridge 19 to an element 22 of the channel on the right hand side of the ridge. During its passage over the ridge 19 the material is subjected to intense working action similar to a rollermill action. In passing along the part of the helical channel closely adjacent to and on each side of the point 20, Fig. 2, the material is subjected to a kneading action resulting from a continual change in the cross sectional shape of the channel. In modifications, (a) Figs. 8 and 9 (not shown) the shank of the working section is formed with a double helix and a continuous double thread extends along the feeding and working sections of the rotor, and (b) Figs. 10 and 11 (not shown) a single-helix helical shank carries a single thread of opposite hand. The pitch, amplitude and/or cross sectional shape and dimensions of the shank portion of the working section of the rotor may vary along the length thereof, and the pitch of the thread or threads may vary along one or more sections of the rotor. Specifications 636,713 and 678,785 are referred to.
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