An oven type cooking device that cooks a food placed in a heating chamber with a heating medium is becoming common among Japanese households. In such a cooking device, usually, a door that is opened and closed in a vertical plane about a lower edge thereof is disposed at a front of its heating chamber. The door is often equipped with a mechanism which is capable of keeping a half-open position of the door. Examples of such cooking devices with a door that is able to be in a half-open state are disclosed in patent documents 1 to 5.
The patent document 1 discloses a gas cooking device in which a recess is formed on a suitable position of an arc-shaped arm that protrudes from a back side of a door, and a roller supported at a free end of a leaf spring engages with the recess, thereby the door is held at a half-open position. The patent document 2 discloses a gas oven in which a recess is formed on an edge of an arc-shaped support arm that is fixed to a door, and a rotor such as a roller or a ball is pressed against the recess by a spring, thereby the door is held at a half-open position. The patent document 3 discloses a gas oven in which a recess for full-open lock and a recess for half-open lock are formed on a tension rod that transmits force of a coil spring to the door, and the recess for half-open lock engages with a detent roller, thereby the door is held at a half-open position. The patent document 4 discloses a duplex roasting device in which a roller fits into one of recesses formed in an arm that is fixed to a door so that an open angle of the door is limited. The patent document 5 discloses a gas oven in which a roller fits into a recess in an arc-shaped arm one end of which is fixed to a door so that the door is stopped at the position.    [Patent document 1]: JP-U-1978-120264    [Patent document 2]: JP-U-1971-9082B    [Patent document 3]: JP-U-1976-21670    [Patent document 1]: JP-U-1975-27067    [Patent document 2]: JP-U-1972-860B