Hollow Piston Hammer Device with Air Equilibration and Idle Openings
AssigneeWacker Construction Equipment AG
InventorsRudolf Berger, Wolfgang Schmid
Life of this patent
Estimating the term…
Abstract
An air spring hammer device comprises a drive piston, moving axially back and forth, with a front face of hollow embodiment and a hammer piston moving in said hollow. A ventilation slot is embodied in a guide wall of the drive piston. The drive piston may be guided in a guide tube. The guide tube comprises several idle openings. A moving control element is arranged on the exterior of the guide tube, in which control openings, corresponding to the idle openings, are provided. In an idle operating mode, the control element is in an open position, via which the ventilation slot, the idle openings and the control openings can be brought into connection with the environment.
Claims19
A pneumatic spring hammer device, comprising:
- a drive piston that moves axially;
- a cavity formed in one end of the drive piston;
- an impact piston that moves axially in the cavity of the drive piston between an impact position and an idle position;
- a least one ventilation slot formed in the drive piston and positioned to fluidly connect an antechamber situated in front of the impact piston and a hollow space enclosed by the drive piston and the impact piston such that air can flow from the antechamber into the hollow space via the ventilation slot;
- a guide tube positioned about the drive piston such that the drive piston is slidably contained therein;
- a plurality of idle openings passing through the guide tube;
- and
- a control element having a control opening, the control element being movable between a closed position in which the control element obstructs the idle openings thereby sealing the hollow space and an open position in which the control opening overlies one of the idle openings to fluidly connect the hollow space to atmosphere to disable operation of the impact piston independent of the position of the drive piston.
A pneumatic spring hammer device, comprising:
- a drive piston that moves axially;
- a cavity formed in one end of the drive piston;
- an impact piston that moves axially in the cavity of the drive piston between an impact position and an idle position;
- a least one ventilation slot formed in the drive piston and positioned to fluidly connect a forward volume situated in front of the impact piston and a rearward volume enclosed by the drive piston and the impact piston such that air can flow from the forward volume into the rearward volume via the ventilation slot;
- a guide tube positioned about the drive piston such that the drive piston is slidably contained therein;
- a plurality of idle openings passing through the guide tube;
- and
- a control element that is movable between a closed position in which the control element obstructs the idle openings thereby fluidly separating a forward volume and a rearward volume that are separated by the impact piston and an open position in which the control element fluidly connects the rearward volume between the drive piston and the impact piston to atmosphere thereby instantaneously disabling oscillation of the impact piston.
A method of controlling operation of a pneumatic spring hammer device comprising:
- generating an oscillation of a drive piston;
- forming a compression between the drive piston and an impact piston to drive the impact piston forward;
- fluidly connecting volumes on generally opposite sides of the impact piston to oscillate the impact piston between an impact position and an idle position;
- and
- selectively venting the volumes to atmosphere via alignment of, a number of control openings formed in a control element, a number of idle openings formed in a guide tube that slidably receives the drive piston, and at least one ventilation opening formed in drive piston and constructed to be overpassed by the impact piston to instantaneous suspend operation of the impact piston independent of the position of the drive piston.
Dependencies are inferred from the claim text.