Abstract: A screening machine that uses electrically controlled transducers to vibrate a separating screen. The transducers can be piezoelectric patches, discrete piezoelectric components, or electromagnetic shakers. Further, the transducers can be coupled directly to the screen or through a vibration amplifier. The transducers and/or amplifiers can be coupled to the screen at different attachment locations. One or more of the transducers can be used as sensors to provide feedback for operation control.

Abstract: A screening machine of the type used to separate or classify mixtures of solid particles of different sizes includes a fixed base and a perforate screen deck mounted for movement relative to the base during a screening operation. Leaf springs connect the tail end of the screen deck to the fixed base so that the leaf springs support the tail end of screen deck for movement relative to the base. The leaf springs are oriented horizontally to avoid introducing vertical movement to the screen deck as it moves to and from the head and tail ends. The leaf springs are offset or deflected when the machine is at rest or in the neutral mid-point of its stroke. This arrangement advantageously utilizes the bias of the leaf springs to accelerate, assist or enhance movement of the screen deck during portions of its stroke and likewise to decelerate, hinder or retard the movement during other portions of its stroke. With an appropriate offset, an increase in the effectiveness of the screening process (i.e.

Abstract: A sieving device and the operation of a sieving device are proposed. The sieving device has a supporting frame which can be made to vibrate and a vibration frame which is held so as to be able to vibrate freely in relation to said supporting frame. A simple, compact design which provides good sieving and conveying performance is achieved in that the vibration frame is spring-elastically coupled to the supporting frame by helical springs, with the main spring axes of the spring elements extending in the direction of vibration of the tension waves. Furthermore, guiding elements for movable bearing arrangement of the vibration frame on the supporting frame are provided. The sieving device is operated in particular at a vibration frequency of at least 850 vibrations per minute at an average speed of approx. 11 m/s and at an average acceleration of the vibration frame relative to the supporting frame of approx. 2.2 m/s2.

Abstract: The invention is related to mining industry, namely to devices for dispersion of solid minerals in particular quartz sands and associated minerals.

Abstract: There is provided screen apparatus comprising side walls having a lower edge portion configured to accept tubular screen support members. An upper edge extends from the inlet end of the side walls to an apex from which a declining edge extends to the foot of the side walls. The lower edge, upper edge and declining edge are each provided with edge stiffening. A torque tube is secured between the respective exciter mount castings, the torque tube and stiffened side wall being selected to provide that the first fundamental frequency mode greater than the exciter frequency is at least 2 Hz greater than the exciter frequency and the first fundamental frequency below the exciter frequency is at least 2 Hz lower than the exciter frequency.

Abstract: In combination, a dump truck mountable particle screener for mounting atop the dump body of a dump truck, and a dump truck. The dump-truck mountable particle screener has a support frame, a screen deck, a plurality of spring assemblies connecting the screen deck to the support frame, and a vibrating mechanism attached to the screen deck for imparting the vibratory motion to the screen deck. The dump truck receives the particle screener atop the dump body.

Abstract: From one aspect the invention is a method of classifying waste materials comprising arranging two sieve screens, each having an inlet end and an outlet end, one above the other to define a space there between, arranging the upper screen, to be of coarser mesh size than the lower screen, supplying waste material to be classified to the inlet end of the upper screen, vibrating the screens, and blowing air between the screens from the inlet end and towards the outlet end whereby the waste material being blown away from the outlet ends of the screens, and large heavy material falling under gravity from the outlet end of the upper screen, and separately collecting the separated waste material fractions. From another aspect the invention is an apparatus for carrying out the method described above.