HYDRAULIC DROP HAMMER FOR COMPACTING FOUNDATION PITS IN SOIL Russian patent published in 2008 - IPC E02D3/02 

FIELD: fixed structures; drop hammer apparatus for compacting foundation pits and breaking wells in soil.

SUBSTANCE: hydraulic drop hammer for compacting foundation pits in soil includes a drop hammer mast with a thrust stop attached to an undercarriage, a slider mounted to said mast, a cable/pulley system for lifting said slider, a guidance mechanism of said drop hammer mast, a working member, a gripping device, a braking mechanism of said gripping device, a lifting and dropping device. Furthermore, the drop hammer mast is equipped in its bottom part with a an extendable foot having a hydraulic control unit, the slider carries an actuator comprising a working cylinder with a piston and rod assembly that interacts with the gripping device having a stroke length exceeding the distance to the release stop of the gripping device, and the piston chamber of the actuator cylinder communicates with a pneumatic accumulator, connected by means of an adjustable orifice to the overflow conduit.

EFFECT: reduced dimensions of the drop hammer; simplified embodiment of the working member retrieval mechanism; control with increased acceleration of the working member.

1 cl, 3 dwg