Abstract: The novel invention proposes a final screen which is very reliable in operation and which is suitable more particularly also for building into a pneumatic conveying line. In a first section the material is distributed uniformly over the entire peripheral surface of the screen shell. The subsequent section is used for completing screening and separating the coarse material out through an outlet. A centrifuging rotor with helically arranged elastomeric cleaning lobes projecting from the centrifuging bars provide a high throughput and particularly damage-obviating discharge of even relatively large foreign bodies.

Abstract: A large or square plansifter has a large number of sieve stacks with e.g. more than 20 sieve boxes. Such boxes are constructed without a supporting grating and design so as to be exchangeable in the covered state and so that they can be placed on or in the sieve frames. A free product fall-through space or discharge space is accordingly formed between the sieve screen and a flat base plate. The sieve cleaners are placed on or in the flat base plate. In a particularly preferred manner, the sieve frames are constructed as metal frames. The sieve cleaners clean the sieve screen and clear the product from the base plate. The sieve cleaners preferably have 2, 3 or 4 arms.

Abstract: A drum type screening machine has a centrifuging rotor within it. A perforated retaining element is carried by the shaft between a feed inlet and an entry region of the drum. Use of the retaining element prolongs the screen life so much that tension adjustment become necessary. Provision is made for this to be done from outside of the machine. The screening drum has a pair of rings which support the screening cloth and which are held apart at an adjustable distance by tensioning bars. One ring is supported within an end member of the machine housing and the other on support means within the housing. Each bar is externally threaded, e.g. by way of an extension sleeve that is axially fast with the bar. The sleeve is engaged by an internally threaded nut which is axially fast with the end member of the machine. The sleeve extends through that nut and through the end member to the outside of the machine.

Abstract: An improved plansifter having an open trough-shaped housing (12) on which is centrally mounted an oscillation generator having a drive motor (40) and a rotary and balance weight (41) for imparting oscillation movement to the housing (12). A pair of sieve stacks (23), each having a plurality of individual sieves (4), is mounted on the floor (16) of the housing (12) stradling the oscillation generator. The housing (12) is suspended for free oscillation. In a preferred construction, the rotary unbalance weight (41) is accelerated by the drive motor (40) to operational speed in a short period of time in order to preclude adverse resonance effects. The deleterious effects which might occur to the structure as it goes through its resonance frequency during acceleration and deceleration of the rotary unbalance weight (41) can be further minimized by providing a suspension means comprising an elastic suspension element (26) at one of four positions on the housing (12).

Abstract: A drum type screening machine has a centrifuging rotor within it. A perforated retaining element is carried by the shaft between a feed inlet and an entry region of the drum. The perforations of the retaining element are small enough to retain the foreign bodies which it is intended to retain but larger than the perforations of the screen. The retaining element has an access aperture, a closure element and means for holding the closure element movably in position to close the aperture. The retaining element can be a basket made up of a perforate plate with a perforate rearward flange. The closure element can be a half-moon segment, located by locating pins and rotatable on the shaft with respect to the remainder of the retaining element on clearing the locating means when pressed axially against the force of a bias spring. Use of the retaining element prolongs the screen life so much that tension adjustment become necessary. Provision is made for this to be done from outside of the machine.