Secretarial shift mechanism for an electric keyboard

Abstract

A secretarial shift mechanism which includes two shift keyswitches and one shift lock keyswitch is disclosed. The two shift keyswitches have T-shaped actuating bars secured to their plungers. The shift lock and release keyswitch has a generally C-shaped wire spring retainer placed around its housing which is utilized to secure a hook on a latching finger on a ledge that is formed on the plunger of the shift lock keyswitch. The latching finger is secured to an elongated torsion bar which has a pair of arms at the ends of the bar that are bent toward the two shift keyswitches. The torsion bar is held at its ends against the frame that holds the keyswitches of the keyboard by clamping caps that project from the shift keyswitches and have grooves in them that receive the torsion bar therein. When the shift lock keyswitch is depressed, a hook on the latching finger that is secured at the torsion bar engages a ledge on the plunger of the shift lock keyswitch and holds it down. Depression of either of the shift keyswitches causes the T-bar on the keyswitch to engage the bent arms on the torsion bar, which in turn results in twisting of the torsion bar sufficiently to deflect the latching finger so the lock is off of the ledge which releases the shift lock keyswitch from its actuated condition.