Patent ID: 7900502

Claim:
A seal checker comprising: a support frame; an elevating mechanism mounted to the support frame; a pair of upper and lower conveyance units disposed above the support frame configured to convey and press a packaging bag by sandwiching the packaging bag therebetween, the lower conveyance unit being mounted on the support frame and the upper conveyance unit being supported by the elevating mechanism; a detection unit configured to detect at least one of a distance between the upper and lower conveyance units and a load applied to the packaging bag when the packaging bag is pressed by the upper and lower conveyance units, the detection unit including a motor; and a determination unit configured to determine seal properties of the packaging bag based on the at least one of the distance and the load detected by the detection unit, the elevating mechanism including first and second oscillating links connected to the support frame, an intermediate link connecting upper end portions of the first and second oscillating links to each other, and configured to move in parallel with the lower conveyance unit with the upper conveyance unit being supported by the intermediate link, and a lower link member connecting the first oscillating link to an output axis of the motor of the detection unit so that rotation of the output axis of the motor causes the first and second oscillating links to elevate the upper conveyance unit, the detection unit being configured to drive the motor to operate the elevating mechanism so that a predetermined space is maintained between the upper and lower conveyance units.