Apparatus for locking a keyboard at selected inclinations to a horizontal reference

摘要

A keyboard is pivotally mounted on a pull out shelf to be raised from a reference position to desired angles of inclination within a range of angles, and is associated with apparatus for positively locking the keyboard following movement of the keyboard to a desired angle of inclination and its release; with the weight of the keyboard acting to maintain locking action. The apparatus effecting the locking action comprises a toothed segment whose arc and teeth define a range of angles. Associated with the toothed segment is a supporting arm biased to follow upward keyboard movement and on which the keyboard after being raised to a desired angle of inclination rests. Cooperating with the toothed segment is a pawl arranged to be deflected by the tooth segment as it follows the keyboard movement to a desired angle of inclination and upon release of the keyboard to engage with a tooth on the toothed segment to positively lock it under the weight of the keyboard thereby to establish the angle of inclination of the keyboard. To establish a lower angle of inclination from a higher angle of inclination, the keyboard and toothed segment are raised beyond the influence of the pawl and then lowered, with the pawl being cammed away by the lowering toothed segment.