Answer:
A rule joint is a type of hinged joint commonly used between a tabletop and a flap or leaf. The purpose of this joint is to create a seamless, flat surface when the leaf is down, leaving no open space or gaps.
The rule joint consists of two interlocking wooden boards that are hinged together. One board is attached to the tabletop while the other is attached to the flap or leaf. The two boards are milled to precise measurements and angles so that when the leaf is folded down, they fit together seamlessly.
When the leaf is raised, the joint allows the flap to be supported at an angle, providing additional surface area. This allows for a larger workspace or dining area, depending on the nature of the furniture.
The design of the rule joint ensures that when the leaf is folded down, it aligns perfectly with the tabletop, leaving no open space or gaps. This provides a smooth and continuous surface, maintaining the aesthetics and functionality of the furniture.
The rule joint is commonly used in furniture pieces such as drop-leaf tables, flap desks, and folding shelves. Its precision and seamless design make it a popular choice for furniture makers aiming to create versatile pieces that can adapt to different space requirements.
Hinged joint, as between a tabletop and flap, which leaves no open space when the leaf is down.