Coffin lock is a slang term for a blind panel connector (also called a butt-joint fastener) often used in scenic construction to join together stage decks or

scenery Theatrical scenery is that which is used as a setting for a theatrical production. Scenery may be just about anything, from a single chair to an elaborately re-created street, no matter how large or how small, whether the item was custom-made or ...

in a

butt joint A butt joint is a joinery, wood joint in which the end of a piece of material is simply placed (or “butted”) against another piece. The butt joint is the simplest joint. An unreinforced butt joint is also the weakest joint, as it provides a ...

. These are two part connectors (male and female) that draw together and lock. The two most common types are the

cam Cam or CAM may refer to: Science and technology * Cam (mechanism), a mechanical linkage which translates motion * Camshaft, a shaft with a cam * Camera or webcam, a device that records images or video In computing * Computer-aided manufacturin ...

and acceptor and more traditional hook and pin version. These devices generally use a

hex key A hex key (also, hex wrench, Allen key and Allen wrench, Unbrako or Inbus) is a simple driver for Bolt (fastener), bolts or screws that have heads with ''internal'' hexagonal recesses (Socket wrench, sockets). Hex keys are formed from a sin ...

to operate the locking mechanism via a small diameter hole either through the face or rear of the panel. When locked, the considerable

mechanical advantage Mechanical advantage is a measure of the force amplification achieved by using a tool, mechanical device or machine system. The device trades off input forces against movement to obtain a desired amplification in the output force. The model for ...

offered by the cam or hook holds the panels tightly together. Coffin locks can be installed directly into a mortise cut into each panel for total concealment except for the locking hole or mounted to the rear of the panels. Many small theatres use stock platforms with coffin locks built into the frames.

References

Stage terminology Stagecraft {{Stagecraft-stub