What Is a Stone Picker Machine and How Does It Work?

Working Principle of Stone Picking Machine

A stone picking machine is a special land preparation implement matched with a tractor. It is mainly used to remove hard debris such as stones, gravels and bricks from topsoil.

Stone Picker is widely applied for soil improvement on farmland in mountains, hills and river beach plots.

The Stone Picker consists of five core components: traction frame, digging device, soil stone screening and conveying mechanism, hydraulic control system and stone collecting hopper. Driven by the tractor for travelling and power transmission, it completes stone cleaning work in one continuous cycle through four operation stages: digging, soil stone separation, stone conveying and collection and automatic unloading.

1. Digging to lift soil stone mixture ：Pulled forward by the tractor, the machine lowers its digging shovel and stone raking tines to a preset depth via the hydraulic system. Stone Picker scoops up top layer soil together with buried stones and lifts the mixture to the rear screening conveying device. The digging depth can be adjusted flexibly according to stone distribution in the field, so that only the target soil layer is cleared and the deep original soil structure is well protected.

2. Vibrating screening for automatic soil stone separation： The soil stone mixture falls onto the slotted chain type vibrating screen. While being conveyed forward, the screen keeps vibrating continuously. Fine soil and sand particles fall back to the farmland through gaps between screen bars, while large size hard objects like stones remain on the screen surface. In this way, soil and stones are separated efficiently with minimum soil loss.

3. Stone conveying and centralized collection into the hopper： Separated stones are transported upward by conveyor chains and stone picking tines and finally delivered into the rear closed stone collecting hopper for temporary storage. The Stone Picker can continuously pick up stones on the ground surface and in shallow soil without frequent shutdowns.

4. Hydraulic unloading for stone removal Once the stone collecting hopper is full, the hydraulic cylinder of the tractor lifts and tilts the hopper to dump stones at the field edge or onto a follow up transport vehicle for unified disposal. After unloading, the hopper resets and the stone picking operation resumes. The cycle repeats until the whole field is cleaned.

The Stone Picker achieves thorough soil stone separation with little disturbance to the topsoil. Compared with manual stone picking, it greatly improves land clearing efficiency. Farmland after stone removal becomes flatter and looser.

Stone Picker can effectively protect subsequent farm machinery such as seeders and rotary tillers from damage, improve cultivated land quality and lay a solid foundation for spring sowing and high efficiency farm production.