Abstract: Disclosed is a device for automatically and continuously lifting and dropping a drop hammer. The device has hydraulic and mechanical components which lift and drop the hammer and electromechanical components which sequence various actions and ensure that the hammer is always dropped from a preset height above its last dropped position. This is useful for soil testing in accordance with America Society for Testing and Materials Test D 1586 "Standard Method for Penetration Test and Split Barrel Sampling of Soils" and other tests.

Abstract: Pile-driving apparatus comprises a drop hammer for imparting blows; a winch for lifting the drop hammer between successive blows, the winch comprising a winch drive, a winch drum, a clutch for disengageably engaging the winch drive with the winch drum, and a rope or cable connecting the drop hammer to the winch drum; a sensor comprising a mercury containing container mounted on the driven object or the hammer and having electrical terminals, for sensing the delivery of a blow by the drop hammer; and a timer. Upon sensing of the delivery of a blow by the drop hammer, the sensor causes the clutch to engage and the timer to be triggered. Upon engagement of the clutch the winch lifts the drop hammer. At the end of a predetermined time interval, determined by the timer, the clutch disengages again, thereby allowing the drop hammer to fall. This process repeats itself automatically.

Abstract: The invention relates to a machine for dropping heavy weights on the ground for carrying out processes of dynamic compaction or dynamic consolidation wherein a brake is provided on the hoist drum which can be actuated automatically after a given period of time has elapsed after the release of the hoist drum brake to drop the weight.

Abstract: A vertical drill rig is provided with a hydraulic crowd mechanism for crowding down a drive kelly having a rotating drilling tool supported from the lower end thereof.The crowd mechanism includes a drum having first and second cables wound in opposite senses thereon. The drum is rotated by a hydraulic motor driven by pressure regulated fluid supplied by an accumulator charged with fluid received from a hydraulic pump. The cables couple the drive kelly to the rig such that, when the hydraulic motor rotates the drum in a given direction, the first cable is paid out to lower the drive kelly while the second cable is simultaneously taken up to crowd down the drive kelly relative to the rig. Such a construction and arrangement provides a substantially constant crowd down force on the rotating drilling tool irrespective of its vertical rate of penetration into the earth.

Abstract: Method and apparatus for forming piles in the earth with a pile hammer rig having a hoisting drum carried by a crane, driving and braking apparatus for the drum, a drop-weight, a hoisting rope leading from the drum for lifting the drop-weight, apparatus for selectively absorbing kinetic energy of the drum and rope disposed adjacent the drop-weight; apparatus for applying the drum brake prior to impact of the drop-weight; and a fluid swivel system for connecting the drop-weight to the hoisting rope.

Abstract: Method and apparatus for forming piles in the earth with a pile hammer rig having a crane, a hoisting drum carried by the crane, a driving mechanism for driving the drum through a clutch assembly, a braking assembly for the drum, a hoisting rope leading from the drum for lifting a drop-weight, an automatic sensor for sensing the top of the drop-weight stroke for disengaging the clutch mechanism, a second automatic sensor for sensing the bottom of the drop-weight stroke for engaging the drum braking assembly, and in one form of the invention an automatic sensor for sensing the rotation of the hoisting drum for disengaging the braking assembly and engaging the clutch assembly.