Butterfly Hinge

Abstract

A butterfly hinge is disclosed comprising a first bracket with an index pin, a second bracket pivotally connected to the first bracket and provided with a pin shaft, and a lever rotatably mounted on the second bracket via the pin shaft. One end of the lever features several inclined first gear notches, while the other end is connected to the second bracket by a spring so that a first gear notch snap-fits onto the index pin under the spring's force. The lever also includes an extension piece slidably movable along its length, with an end extending beyond the lever and provided with an inclined extension slot adapted to mate with the index pin. The second bracket rotates relative to the first up to or near 180° to allow the sofa back to fold onto or near the sofa base's top surface, thus reducing sofa volume for compact packaging and transportation.

Dependencies are inferred from the claim text.