Abstract: A support for the plates of filter presses and filters for filtering over a filter wall, for instance over a filter cloth or filter paper. The support is provided with regularly oriented projections. The upper surfaces of the projections, which are in contact with the filter wall, are provided with grooves.

Abstract: Mold for the injection molding of objects of large dimension and complicated surfaces from plastic material without internal stresses and with accurate dimension. In base plates of the mold cooling grids are embedded and the active surface of the base plates is provided with forming plates and forming strips with grooves for heating elements or tempering and cooling means. The mold is provided with mobile cores which change their positions in the course of shrinking of the solidifying plastic material.

Abstract: Voluminous products of plastics are made by providing between a filling cylinder of the injection part and the mould a transfer chamber with a piston, the axis of which does not coincide with the axis of the filling cylinder.

Abstract: A filter assembly includes a monolithic thermoplastic structural element having parallel sealing surfaces, the element being either a filter frame or a filter support. The material of the element is denser at its surface than in its inner portions. When the element is a filter support, it has a system of filter grooves extending in its surfaces, which may be connected to a discharge outlet by way of a further groove which has a dimension increasing toward the discharge. When the element is a filter frame, it may be provided with a support body in the sludge space, having bases parallel with the sealing surfaces of the element. One or more inlet ports to the sludge space of the frame are provided, which flare outwardly toward the sludge space. The element may be provided with oval or circular recesses extending from edges between the parallel sealing surfaces, and the element may be provided with a projection on its edge, to which a holder may be affixed.