Illinois Tool Works Inc.

Stanley E Filipiak

John K McVey

Charles J Shedore

Robert J Keeler

An apparatus for stabilizing operational movement of an actuator for a keyswitch mounted to a base, which has one or more unitary, substantially rigid members, which members are movably attached to the actuator at a first end and have a gripping means at a second end for slidingly gripping a free edge of the base.

Keyswitch stabilizing device

A capacitive keyswitch is formed with a fixed horizontal plate that is imbedded in a horizontal printed circuit board below an overlaying dielectric layer and a moveable cantilever mounted plate that is hinged to the printed circuit board so as to project upwardly at an acute angle. When a plunger is actuated, a portion of it presses down on an overtravel mechanism that is formed from the moveable plate which causes the moveable plate to assume approximately a parallel position with respect to fixed horizontal plate, thereby changing the capacitance of the switch and actuating the switch. The overtravel mechanism consists of a tab cut out of a bent-up portion of the moveable plate so that the tab is bent along an intersection line formed by the intersection of the plane or moveable plate and the plane of the bent-up section.

Capacitive keyswitch with overtravel mechanism on moveable plate

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.

Growing community of inventors

Chicago, IL, United States of America

Stanley E Filipiak