Airbag and airbag apparatus

An airbag to be inflated by gas for a vehicle, comprising:

• a base member for forming the airbag, the base member including, at a side facing a seated occupant, a head-facing portion adapted to receive a head portion of the seated occupant thereagainst when the airbag is inflated, first and second vertically extending bulbous portions with a vertically extending recessed portion therebetween when the airbag is completely inflated, the recessed portion defining the head-facing portion adapted to receive the head portion of the seated occupant thereagainst;
• a vent provided in the base member;
• and
• a control member for restraining gas from discharging through the vent, said control member closing the vent when an occupant does not contact a front surface of the airbag facing the occupant when the airbag is inflated, and opening the vent when the occupant contacts the head-facing portion and the head-facing portion is pushed in a direction opposite to the occupant,
• wherein the control member comprises:
• a vent flap disposed on an external surface of the airbag, and
• a tether which has:
• a first end connected to an inner surface of the airbag at the recessed portion of the head-facing portion,
• a portion which extends substantially horizontally in an unrestricted, contact free state through an interior of the airbag and which passes out of the airbag through a tether insertion portion provided in the airbag, and
• a second end connected to the vent flap externally of the air bag, the vent flap and the tether being connected in a manner to maintain the vent closed by the vent flap while a predetermined tension exists in the tether extending through the interior of the airbag.