Patent ID: 8804462

Claim:
A marine vibrator, comprising: a housing having a first portion and a second portion, the second portion of the housing disposed coaxially with the first portion and radially inward of the first portion; a piston movably disposed within the housing, the piston disposed within the first portion of the housing, and the second portion of the housing disposed within the piston; a first seal disposed between the piston and the first portion of the housing; a second seal disposed between the piston and the second portion of the housing, the second seal being located radially inward of the first seal; a first internal cavity within the housing defined by the first seal, the second seal, the piston, the first portion of the housing and the second portion of the housing; and a second internal cavity within the housing defined by the second seal, the second portion of the housing and the piston, the second internal cavity separated from an external environment by the first cavity.