A Pneumatic Toggle clamp is a basically a Toggle Clamp actuated with a double acting pneumatic cylinder.
The Clamps consists of a double acting cylinder, a clamping arm, linkages for multiplying the applied force, and a base for mounting at the workplace on its base.
Air pressure in applied in the clamping port, which thereby moves the clamping arm to hold the work piece. A required clamping force is achieved and exerted on the work piece. Under this action the Toggle Clamp Holds the work piece firmly and positively. To unlock the clamp the air pressure is applied in the unclamping port.

Hold Down Action Pneumatic Clamps
These clamps utilize the same basic design and operation as manual hold down, only they are operated pneumatically. As the clamp uses the toggle action principle it ensures that the clamp stays locked in the event of air failure.
These clamps are extremely compact in design and feature an incredibly low height, allowing free movement of operating tools in drilling, tapping, milling etc. The clamp units are completely selfcontained with a double acting cylinder and require only to be connected to the airline. The clamping arm exhibits a minimum 95 opening angle for easy unloading of workpiece and is available in two different options.