| 摘要 |
A hinge device particularly adapted for positioning a work surface in a vertical in-storage position or a horizontal in-use position comprises a first and a second arm. Each arm is defined by an elongated segment connecting with an angularly positioned short segment. An end of first arm short segment is pivotally attached to an upper end of a support member. An end of the first arm elongated segment in turn is pivotally attached to an outer part of the work surface. In the first arm elongated segment is a slot positioned inward from the end. An end of the elongated segment of the second arm is pivotally attached to a lower end of the support member. An end of the second arm short segment in turn is pivotally attached to an inner part of the work surface. In the second arm short segment is a recess defined in part by an inner support ledge. To move the work surface from its vertical in-storage position to its horizontal in-use position the work surface first is raised to a point above the horizontal where the second arm-work surface pivot connection is located in the first arm slot. Then, the work surface may be lowered to its horizontal in-use position and there supported by an interference fit between a bottom edge of the first arm elongated segment and the second arm recess inner support ledge.
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