Locking device for sewing machine cabinet support platforms

A sewing machine cabinet having a sewing machine support platform pivotable about a fixed axis from a stored position within the cabinet to a substantially horizontal operative position where it is locked in place by means of a pair of bolts mounted on opposite sides of the platform, and received within sockets formed on corresponding keepers pivotably mounted on brackets secured on the cabinet side walls. Each keeper includes three cam surfaces, two of which are effective to rotate the keeper in a first direction when acted upon by respective bolts. A spring secured to each keeper to oppose the rotation of keeper in the first direction until the keeper rotates to a position where the spring swings over-center and thereafter aids turning the keeper in this direction. The third cam surface is effective to turn the keeper in the opposite direction to that of the first two cam surfaces. As the platform is pivoted into the operative position the bolts engage the first cam surface and rotate the keeper against the bias of the springs. When the bolts are above the sockets the springs return the keepers to the normal positions and the platform may be lowered to position the bolts into the socket. To store, the platform is pivoted upwardly until the bolts engage the second surface rotating the keepers until the springs have moved over-center. The platform is then moved downwardly free of the sockets and engage the third surface to rotate the keepers into their original position.