Patent ID: 8613735

Claim:
A suction device, comprising: an outer tube including a base-end side and an opening edge section, the outer tube being connected to a fluid supply unit on the base-end side of the outer tube; a suction tube provided in the outer tube and including a base-end side and an opening edge section, the suction tube being connected to a negative pressure generating unit on the base-end side of the suction tube, wherein an annular fluid supply passage, configured to supply fluid from a distal end thereof, is formed between an inner peripheral surface of the outer tube and an outer peripheral surface of the suction tube, and the opening edge section of the suction tube is placed inside the opening edge section of the outer tube toward the base-end side thereof; and an adapter connected to the base-end side of the outer tube and the base-end side of the suction tube, the adapter having a fluid supply port that connects the outer tube to the fluid supply unit and a suction port that connects the suction tube to the negative pressure generating unit, wherein the annular fluid supply passage is configured to allow the fluid to exit the distal end thereof in a direction along a longitudinal axis of the outer tube, and the opening edge section of the suction tube is spaced from the opening edge section of the outer tube to define an annular fluid exit at the distal end of the annular fluid supply passage.