Door and board carry clamps work by clamping onto the edge of sheet material through a lever action. Lifting the handles forces the clamps towards each other, trapping the material to be carried in between. The heavier the material, the greater the force applied through the clamps. This secures the clamps firmly in place.
Single-handed door and board carry clamps
The clamping pads of these carriers are attached with a lever which is operated by a handle. When the handle lifts, the bar joining the pads tilts, and the pads move together. As one pad moves down, the other moves up, bringing them together. As long as the handle is being lifted the pads will stay shut.
Double handed door and board carry clamps
Carry clamps with two handles work with two levers crossing each other, like scissors. The gripping arms of these carriers are joined by two bars which cross each other. When both handles are lifted the arms close. When the handles are moved apart the arms open.