Tire testing machine

A tire testing machine comprising:

• a bottom frame;
• a pair of vertical frames that is supported by the bottom frame and extends upward in the vertical direction from the bottom frame;
• a movable beam that is laid across the pair of vertical frames;
• a first chuck that includes a first spindle rotatable about an axis following the vertical direction;
• a second chuck that is mounted to the movable beam, is engageable with the first chuck, and includes a second spindle rotatable about an axis following the vertical direction along with the first spindle;
• a screw shaft that is mounted to the vertical frame and is rotated by a driving unit so as to cause the movable beam to ascend or descend;
• and
• a beam fixing member that fixes the movable beam when a gas is supplied to an inner space of a tire clamped between the first chuck and the second chuck,
• wherein the beam fixing member includes a disk that is fixed to the screw shaft and is provided with a plurality of elongated holes elongated in the circumferential direction of the disk and a disk fixing member that is fixed to a stationary object and includes pins to be inserted into the holes,
• wherein the pins have a length in the circumferential direction of the disk which is less than a length of the elongated holes in the circumferential direction of the disk, and
• wherein when the pins are inserted into the holes formed in the disk, the second chuck is fixed to the first chuck through the movable beam.