Mutual locking device for an office machine with electric keyboard

Claim 2

An electric office machine comprising a keyboard a cyclic actuating mechanism operated when each key of said keyboard is depressed, locking means actuated by the simultaneous depression of two or more keys to prevent operation of said actuating mechanism, and motor-driven lock release means for releasing said locking means, said release means comprising a powered, continuously oscillating member, a release element engageable by said oscillating member and operatively connected to said locking means to release said locking means when engaged by said oscillating member, and a release key operatively connected to said release element for moving said release element into the path of said oscillating member when said release key is depressed.

Claim 3

An electric office machine according to claim 1 wherein said release element is a pivotally mounted first pawl, the depressing of said release key causing said first pawl to pivot into the path of said oscillating member to be engaged thereby.

Claim 4

An electric office machine according to claim 1 wherein said oscillating member is driven continuously by a multiple-lobe cam.

Claim 5

An electric office machine according to claim 2, wherein a common actuator performs a forward stroke by the action of a spring in order to actuate a mechanism associated with each depressed key, and a return stroke by the action of the cyclic actuating mechanism, which is actuated through a coupling closed when a control member is released upon depression of the key, the locking means comprising a detent which is adapted to temporarily engage the control member in a locked position during each cycle, the common actuator disengaging the detent at the end of its forward stroke, the stroke of the common actuator being shortened when two keys are depressed simultaneously so that the detent leaves the control member in the locked position, the release element being coupled to the detent to disengage the detent when the release element is moved by the oscillAting member.

Claim 6

An electric office machine according to claim 4, wherein the release element disengages the detent through a second pawl pivotally mounted on a member carrying the detent, and engaging portion integral with the member on which the first pawl is pivotally mounted being adapted to coact with the second pawl so as to disengage the detent during one forward or return stroke of the last said member.

Claim 7

An electric office machine according to claim 5, wherein the second pawl is connected with the last said member by means of a one-way coupling such that the engaging portion, during its forward stroke, snaps past the second pawl, whereas during the return stroke, actuated by a spring, it will displace the second pawl and the member carrying the detent through the one-way coupling.

Claim 8

An electric office machine according to claim 6, wherein the common actuator comprises an oscillating flag and each said mechanism associated with each depressed key comprises a type mechanism of a typewriter including type bars and an intermediate lever with one arm connected to the type bar and individually engageable with the flag, the flag being prevented from reaching the end of the forward stroke by prematurely arresting the intermediate levers with arrest means acting upon the intermediate levers when at least two of these levers have been engaged by the flag.

Claim 9

An electric office machine according to claim 7, wherein arrest means comprise a set of balls disposed in the path of portions of the intermediate levers opposite to the one arm and adapted to allow displacement of only one intermediate lever at a time.

Claim 10

An electric office machine according to claim 8, wherein each intermediate lever is engaged with the flag by means of an entrainment lever pivotally mounted on the intermediate lever and normally held in the inoperative position by a hook also pivoted on the intermediate lever and adapted to disengage the entrainment lever upon depression of the corresponding key, the release element being coupled to a universal bar which, upon actuation of the release element, engages a portion of the disengaged entrainment levers, thereby re-engaging these levers with the corresponding hooks.

Claim 11

An electric office machine according to claim 9, wherein each hook is actuated by a corresponding strut for disengaging the entrainment lever, (each strut being pivoted to an intermediate lever cooperating with the corresponding key lever, the various intermediate) each type mechanism also comprising another intermediate lever pivotally mounting the corresponding strut and a key lever secured to the corresponding key and cooperating with said other intermediate lever, all said other intermediate levers being pivotally mounted on a first common axis disposed at the back of the keyboard, (the various) all said key levers being pivotally mounted on a second axis disposed in the front of the keyboard, and a motor shaft for driving the cyclic mechanism and the oscillating member being disposed between the said two axes and below the plane passing through them.