In the course of bar-cleaning the hydraulic system, which is assembled on the trolley, gives to the comb a rotation towards the canal-bed of the riddling bars. At the bottom the bars are shaped in such a way as to help the comb raking-up working; in fact they end in a bending radius which measures 400 millimetres. The rotation causes a progressive coming of the comb-teeth into the bars. In this way the comb-teeth carry the bottom material towards the bars before; afterwards they begin by cleaning the vertical part. While the trolley comes down, the rotating comb is open (it’s parallel to the bars). At the discharge outlet a scraping blade cleans the comb draining away the material on to the back of the fixed skid. The rotating comb wheels around over some flanged pins on which are assembled some special bushes in self-oiled material. The comb-holder trolley is provided with some wheels in bronze material or in a special material (Derlyn). These wheels make it possible to shift the trolley inside of the two side-runners. The wheels fit together upon some fixed or flanged pins which are arranged on the trolley flanks. It is possible to pull completely out the comb-holder trolley from the machine in case of eventual overhauling or important repairs.
The bar section includes some flat structural shapes which standard thickness is: 40x8, 40x10, 60x10 centimetres. Other sections are used by request. At the bottom of the machine the bars are fixed to the plate lying on the ground, whereas at the top they are fixed to the structure of the bar extension. As regards the construction there are no limits about the height of the bars. The least cleft among the bars measures 12 millimetres; in case of smaller clefts (2-8 millimetres) the bars are replaced by an extractible riddling panel made of stain-less steel (AISI 304-316) including some trapezoidal bars that can’t be stopped up. The panel has the same shape as the standard bars and it is kept clean by a scraping comb provided with a brass blade. The characteristics of the CR model machines are strength, best assurance, simplicity of working, which makes the machine functional and cheap. The speed gear of the machine doesn’t generally exceed 3,2 metres; however quicker movements are also possible when a telescopic cylinder going out twice is used for the trolley shifting. There are two standard models; the 2CR model is used for canals up to one metre and a half wide, whereas the 3CR model is used for canals up to two metres wide. The 3CRL model is employed for canals from 2 metres to 3,5 metres wide. The machines that we supply may be suitable for a vertical execution. The oleodynamic pipelines are generally joined to a special pipe-stand which is fixed to the upper girder. As an optional fitting we assemble a pipe-winder drum.
It is very important to point out that inside of the machine there isn’t any kind of electrical equipment or electromechanical equipment, which makes it possible a safer installation especially in humid environments running a flooding danger or in explosion-risk areas. All the hydraulic operations inside of the machine are regulated by a hydraulic power plant staying apart from the machine and laying down everywhere. Inside of the power plant (as a standard fitting) we assemble an electric panel which is used for the control and the inspection of the screen. The electrical cables of the hydraulic power plant are protected by some oil-less sheathings. The power plant is provided with a branch-circuit box and a terminal board when the electric panel is discorporate from the power plant. The machine works making breaks which can be anyway tuned up. During the break the trolley always stops at the top of the machine. In case of stress or difficulties during the working the trolley automatically reverses.
The machine is furnished with CE mark and it can be supplied with different optional fittings.