There are certain jigging units with movable sieve (Directory on ore processing. Main processes. Moskow, Nedra, 1983, p.p. 53-54). The sieve is given bow-shaped movement with horizontal displacement towards the place of loading material with the sieve moving down and protruding it forward under moving up. As a result the positive effect is achieved due to simultaneous up going of the whole bed and pushing separating material forward along the sieve, the regulation of the sieve movement is done by replacement of the plates with cranks on the movable disks.
Disadvantage of the device is insufficient disintegration of the movable bed in the loading part of the sieve and mixing up of disintegrating fractions in the loading part. Thus, the efficiency of material disintegration is low. Due to these reasons as well as some others the type of the devices with the movable sieve did not find wide application.
There are jiggers with unmovable sieve, such as “THE WEMCO REMER JIG” (Annotation of the device—“THE WEMKO REMER JIG” WEMCO EGUIPMENT, COAL PLANTS 315C Street, St. Albans, W.Va.).
The device has an upper unmovable trough with a sieve and a lower movable one, both are connected by rubber diaphragm along perimeter. The lower trough gets vertical reciprocating movement by special doubled eccentric mechanism. As a result vertical pulsation of under-sieve water is being achieved that is very important for jigging.
Disadvantages of the machine are complexity of the design due to eccentric unit construction, high inertia of the lower part of the machine that results in high energy-consumption because of the fact that each cycle of jigging needs upraising of the lower trough with the whole amount of water, low efficiency of jigging as there is no simultaneous upraising of the whole bed that is characteristic of all jiggers with unmovable sieve.
As a prototype of a jigger, the machine with vibrating of the jigging sieve and water in counter-phase is used (Jigging machine. International Patent Classification B03B 05/16, international publication number: WO 02/13974, international publication date: 21 Feb. 2002 (21 Feb. 2002)). The machine consists of troughs connected hingedly by double-arm levers, the upper having a sieve inside and continuous flexible membrane at the bottom interacting with lower trough. The double-arm levers are hinged upon supports. Reciprocating movement of troughs is achieved by setting a drive in the center of axle of double-arm levers rotation, for example, turning gate hydraulic engine. Thereby reciprocating movement of troughs is taking place both in vertical surface—for jigging performance and in the horizontal one—for transporting processing mineral to the place of unloading out of the jigger. The double-arm levers together with troughs form a system of hinge parallelogram, that results in uniform pulsation of under-sieve water and simultaneous uprising of the whole bed, that's very important for efficiency of jigging.
Because of the cinematic scheme and correspondingly the design itself the disadvantages of the machine are that the troughs make reciprocal motion and as result of this the considerable part of the drive capacity is spent to overcome inertia rather than to the useful performance. Besides it result in considerable additional loads over the drive and hinges of the machine that is negatively effects reliability of the machine.