What is the mechanism of clamshell bucket?

The clamshell bucket consists of two hinged halves that resemble clam shells. These halves are connected by a hydraulic cylinder or cylinders that control their opening and closing movements.
The Clamshell Grab Bucket Operating Mechanism
Hydraulic Power: The operation of the clamshell bucket is driven by hydraulic power supplied by the excavation equipment. Hydraulic fluid is pumped into the cylinders to create the force needed to open and close the bucket halves.
Opening and Closing: When the operator engages the control for opening, hydraulic fluid is directed to one side of the cylinder(s), causing the bucket halves to spread apart. Conversely, when closing is commanded, fluid is directed to the opposite side of the cylinder(s), forcing the halves together.
Material Handling: With the bucket clamshell closed, theclamshell bucket can grasp and hold materials such as soil, gravel, rocks, or bulk materials like sand, coal, or grain. The powerful closing force allows it to securely hold the material even if it is irregular in shape or size. Digging and Loading: The operator can use the excavator's arm to position the clamshell bucket in the desired location for digging or loading. The grab bucket halves can be scooped up by opening the bucket halves, and then the halves are closed to retain the material during transport.