US 6,568,484 B1Granted

Pneumatic piston percussive mechanism with a hollow percussion piston

AssigneeWacker Construction Equipment AG

InventorsWolfgang Schmid, Mirko Lysek, Rudolf Berger

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Abstract

The invention relates to a pneumatic percussive mechanism for a percussion drill and/or a drill hammer. The inventive mechanism comprises, housed in the housing of the percussive mechanism, an axially reciprocating percussion piston. A drive piston is axially reciprocated in a guide cylinder of said percussion piston. The guide cylinder is provided on its inner face with one or more air compensation pockets. At least one idle opening extends through the guide cylinder. In the percussive action, the idle opening does not communicate with the ambience while in the idle mode the idle opening can be displaced via an idle channel that leads to the ambience and thus connects a cavity that receives a pneumatic piston with the ambience by way of the idle opening. The air compensation pockets and the idle openings allow and optimization of the piston return behavior and of the idle operation of the percussive mechanism.

Claims14

Dependent claims

An air spring impact mechanism for a sledgehammer and/or hammer drill comprising:

an impact mechanism housing;
a percussion piston that moves axially back and forth and is hollow at one end and has a guide sleeve that slides within the impact mechanism housing;
a drive piston that moves inside of the guide sleeve of the percussion piston axially back and forth;
a cavity located between the drive piston and the percussion piston that forms an air spring;
wherein
at least one air equalization pocket extends axially along the inside of the guide sleeve of the percussion piston;
wherein
the guide sleeve of the percussion piston has at least one idle opening penetration;
an idle channel is designed into the impact mechanism housing that communicates with the surroundings;
no connection between the idle opening and the idle channel occurs during impact operation of the air spring impact mechanism, and that;
during idle operation, the idle opening can be moved over the idle channel and the cavity can be put in connection with the surroundings through the idle opening and the idle channel.

8 more elements

Dependencies are inferred from the claim text.