Patent GB-150269-A (GB)
Title: Method of and apparatus for mixing and kneading
IPC: B29B7/12
Filed: 1920-08-16
Abstract: 150,269. Lohmann, A. P. Aug. 16, 1919. [Convention date]. Stationary ba t c h mixers with rotary stirrers.-A machine for mixing and kneading rubber or other gums with various pigments and other materials consists of a casing containing a rotary member provided with oppositely disposed helical blades extending from the sides of the casing to considerably beyond the centre so as to cause the material to move from end to end of the casing, and, in addition, smear it against the inner surface of the container, a blade or interrupter being provided in the chamber to prevent material from becoming lodged beneath the smearing-surface and the chamber walls. The mixing member 13, Fig. 1, is mounted in bearings on a chamber 12, preferably of cylindrical cross-section, and is provided with two or more helical blades. These blades 14, 15, Fig. 5, are of opposite twist, and overlap considerably at the centre, leaving gaps, such as 16, between the ends of the blades. Thus as the member rotates, the material in contact with a blade, say 14, is forced along towards one end of the chamber, and then passes through the gap 16 and is forced by the blade 15 to the other end of the chamber, and so on. Each of the blades has its edge, 14<b>, 15<b> respectively, bevelled, as shown in Fig. 8, so that the material which is forced outwards by the surfaces 14<a>, 15<a> of the blades is smeared against the inner surface of the chamber. These smearing- surfaces may be made integral with the blades, as shown, or separable. The ends of the blades may be spiral in order to remove material adhering to the end wall of the chamber. The mixing chamber, and the interior of the member 13, may be heated or cooled by steam or water supplied through pipes such as 20, Fig. 1. The door 22 of the mixing chamber is hinged at 21, and is closed by means of a fluid-pressure cylinder 11, the piston of which is connected to the door by a flexible member 26. The piston may also be applied directly to the lower part of the door. The hinge of the door is so constructed as to leave a blade or interrupter projecting within the cylinder. This blade breaks up any tendency for the material to remain lodged between the smearing-surface and the cylinder. Certain ingredients, such as pigments, which are to be mixed with the material in the chamber are contained in a drum 33, Fig. 4, which is mounted on revoluble members 27, 28, Figs. 1 and 4, in a recess in the door. The members 27, 28 screw into eccentric bosses 38 in the ends 34 of the drum, and are capable of limited longitudinal movement in their bearings. The ends of the drum are connected to the body by bayonetjoints 35, which permit them to be lifted a short distance off the body without becoming detached. In use, a filled drum is placed in position and the door closed. A pinion 40 on the member 27 engages a sprocket 39 driven by the member 13, so that the drum is rotated. When the contained pigments are to be introduced into the mixing chamber the members 27, 28 are pulled outwards. The ends of the drum are thus lifted off the body and the contained material is allowed to escape into the chamber, the eccentric mounting of the drum assisting in shaking out the material.