Electric keyboards for office machines

Claim 2

An electric keyboard having a plurality of depressible projecting keys, at least one movable electric contact for each of said keys and operable to close a circuit by bearing on a fixed contact, said movable contacts being together connected to form a comb collector, and a plurality of shanks connected to a corresponding of each one said keys for operating said movable contact, wherein: each of said movable contacts comprises an extended thin flexible blade attached at one end to a stationary guide plate and the other end having shaped thereon a contact surface for contacting said fixed contact and being free for movement between an inoperative position and said fixed contact, said blade fixing one extremity of an actuating tongue projecting between the two ends of said blade, the other extremity of said tongue bearing on a fixed stop located above the line joining the attached end and said fixed contact, and said tongue being bent in arcuate form for pulling upwardly said contact surface, said shank pressing said flexible blade at a point located between said point of attachment and said fixed stop in order to cause said one extremity of said tongue to pass over the line joining said attached end and said fixed stop so that said contact surface is snap pulled downwardly for bearing said fixed contact, said flexible blade snapping back in the inoperative position when said depressed key is released.

Claim 3

Keyboard as in claim 1, wherein each of said shank is constantly urged upwardly by said blade in a corresponding rectilinear guide formed in said guide plate, said shank having on its upper part an integral flange protruding from said plate and further comprising a layer of deformable material covering said guide plate and shaped in Such manner as to form said projection key over each of said flanges so as to seal hermetically said plate and to define a cavity between said projection and said guide plate in which said flange is moved.

Claim 4

Keyboard as in claim 1, wherein said tongue has said one extremity fixed to said other end and extends said other extremity towards said attached end said tongue being centered between two laterals straight rails of said blade, said other end forming said contact surface by an arcuate bent which assumes a S-shaped profile with said tongue.

Claim 5

An electric keyboard comprising: a plurality of keys obtained by projections of a layer of deformable material; a guide plate supporting said layer as to be sealed hermetically by the layer and defining a cavity for each projection; at least one movable electric contact for each of said keys, said movable contact including a thin flexible blade attached at one end to said guide plate and having the opposite end shaped as to form a contact surface for contacting a corresponding fixed contact; said blade, in correspondence of said contact surface, having a portion extending toward said attached end, said portion being bent in arcuate form and having one extremity bearing on a fixed stop of said plate; and a shank for each of said projections movable on said plate, each shank protruding in each cavity and having an integral flange normally spaced from the projection in the cavity, said shank having an extremity cooperating with said flexible blade at a point located between the said point of attachment and the said fixed stop as to cause, when depressed, said arcuate portion to produce snap contact between said contact surface and said fixed contact after the flexible blade has reached a predetermined position, the flexible blade snapping back said shank into the inoperative position when the projection is released.

Claim 6

An electric keyboard comprising: a plurality of keys obtained by projections of a layer of deformable material; a guide plate supporting said layer as to be sealed hermetically by the layer and defining a cavity for each projection; at least one movable electric contact for each of said keys, said movable contact including a thin flexible blade attached at one end to said guide plate and having the opposite end shaped as to form a contact surface for contacting a corresponding fixed contact; said blade, in correspondence of said contact surface, having a portion extending toward said attached end, said portion being bent in arcuate form and having one extremity bearing on a fixed stop of said plate; and a shank for each of said projections movable on said plate, each shank protruding in each cavity and having an integral flange normally spaced from the projection in the cavity, said shank having an extremity cooperating with said flexible blade at a point located between the said point of attachment and the said fixed stop as to cause, when depressed, said arcuate portion to produce snap contact between said contact surface and said fixed contact after the flexible blade has reached a predetermined position, the flexible blade snapping back said shank into the inoperative position when the projection is released.

Claim 7

In a keyboard for electronic calculating machine in which the external layout of set of keys forms at least one matrix of rows and columns of keys, wherein said key is obtained by a projection of a layer of deformable material, the combination including: a comb collector of movable contacts comprising for each projection one corresponding extended thin flexible blades, said blades being parallel each other and with respect to the columns of said matrix of projection, said blades having a free contact end and a common opposite integral end, said integral end being fixed, a portion of said blade being bent in arcuate form and bearing on a fixed stop as to cause said free contact end to move between a stable inoperative position and an instable contact position to touch a corresponding conductive contact area with a snap action when a pressure is exerted on said blade at a pressure area located between said opposite integral end and said fixed stop, said blade snapping back in said stable position when said pressure is ceased, said pressure area, in a first group of said blades, corresponding to projections of a first of said rows, being aligned with the column of projections of said first rows and, in a second group of said blades, corresponding to projections of a second of said rows, being misaligned with the column of the projections of said second rows, a stationary guide plate at which said integral end of said blade is fixed, said guide plate having openings in correspondence to each of said pressure areas, said openings for said first group of said blades comprise corresponding rectilinear guide holes perpendicular to said flexible blades and for said second group of said blades said openings comprise a shaped slits joining the projections of said second rows with the corresponding pressure areas, a shank for each of said projections for operating said blades on said pressure areas, said shank of said first group of said blades being a pin housed in each of said rectilinear guide holes and located below said corresponding projection of said first rows, said shank fOr said second group of blades being a member pivotable in said plate, said member having a first part bearing on said pressure area and a second part cooperating with the projection of said second rows, said member being housed in said shaped slit for transmitting the finger pressure from said projection to said pressure area, said pins and members being constantly urged upwardly by said blades and said layer covering said guide plate so as to seal hermetically said openings.

Claim 8

In a keyboard for electronic calculating machine in which the external layout of set of keys forms at least one matrix of rows and columns of keys, wherein said key is obtained by a projection of a layer of deformable material, the combination including: a comb collector of movable contacts comprising for each projection one corresponding extended thin flexible blades, said blades being parallel each other and with respect to the columns of said matrix of projection, said blades having a free contact end and a common opposite integral end, said integral end being fixed, a portion of said blade being bent in arcuate form and bearing on a fixed stop as to cause said free contact end to move between a stable inoperative position and an instable contact position to touch a corresponding conductive contact area with a snap action when a pressure is exerted on said blade at a pressure area located between said opposite integral end and said fixed stop, said blade snapping back in said stable position when said pressure is ceased, said pressure area, in a first group of said blades, corresponding to projections of a first of said rows, being aligned with the column of projections of said first rows and, in a second group of said blades, corresponding to projections of a second of said rows, being misaligned with the column of the projections of said second rows, a stationary guide plate at which said integral end of said blade is fixed, said guide plate having openings in correspondence to each of said pressure areas, said openings for said first group of said blades comprise corresponding rectilinear guide holes perpendicular to said flexible blades and for said second group of said blades said openings comprise a shaped slits joining the projections of said second rows with the corresponding pressure areas, a shank for each of said projections for operating said blades on said pressure areas, said shank of said first group of said blades being a pin housed in each of said rectilinear guide holes and located below said corresponding projection of said first rows, said shank fOr said second group of blades being a member pivotable in said plate, said member having a first part bearing on said pressure area and a second part cooperating with the projection of said second rows, said member being housed in said shaped slit for transmitting the finger pressure from said projection to said pressure area, said pins and members being constantly urged upwardly by said blades and said layer covering said guide plate so as to seal hermetically said openings.

Claim 9

Keyboard as in claim 5, wherein said portion of said blade is a tongue having one extremity fixed at said free end contact, projecting between the two ends and centered between two lateral straight rails of said blades, the other extremity of said tongue bearing on corresponding fixed stops integral with said guide plate, and said guide plate having furthermore windows housing said tongues.

Claim 10

Keyboard as in claim 5, wherein said comb collector has two opposite rows of blades connected together by a common central part.

Claim 11

Keyboard as in claim 7, wherein said comb collector is electrically energized by an additional common blade integral and parallel to said blades constantly contacting with a common conductive area.

Claim 12

Keyboard as in claim 5, wherein each of said pivotable member has said integral cylindrical member and flange shifted in the same side with respect to said axis of rotation.

Claim 13

In a digital calculating machine, designed for use as a hand held machine, the combination including: at least one unpackaged integrated circuit comprising a chip having electronic circuits for performing arithmetic functions; one piece conductive terminals directly connected to said electronic circuits; a protective cap; an insulative substrate fixing said chip and having a portion prepared for placing said protective cap over said chip; a source of voltage; a keyboard including flexible, electrically conductive, contact tongues which are disposed above said substrate and which have at least a single contact projection, said tongues being responsive to the activation of keys by bending toward said substrate; means for connecting said tongues to said source of voltage; and a first electrically conductive interconnection pattern, said first pattern being deposited on said substrate being directly connected to said conductive terminals and extending from said chip to contact portions of said pattern which are directly below said contact projections, the depression of a key causing a contact projection to bend until making contact with the corresponding one of said contact portions causing an electrically conductive path to be completed between said source of voltage and the circuit of said electronic circuits connected to said corresponding one of said contact portions.

Claim 14

In a digital calculating machine, designed for use as a hand held machine, the combination including: at least one unpackaged integrated circuit comprising a chip having electronic circuits for performing arithmetic functions; one piece conductive terminals directly connected to said electronic circuits; a protective cap; an insulative substrate fixing said chip and having a portion prepared for placing said protective cap over said chip; a source of voltage; a keyboard including flexible, electrically conductive, contact tongues which are disposed above said substrate and which have at least a single contact projection, said tongues being responsive to the activation of keys by bending toward said substrate; means for connecting said tongues to said source of voltage; and a first electrically conductive interconnection pattern, said first pattern being deposited on said substrate being directly connected to said conductive terminals and extending from said chip to contact portions of said pattern which are directly below said contact projections, the depression of a key causing a contact projection to bend until making contact with the corresponding one of said contact portions causing an electrically conductive path to be completed between said source of voltage and the circuit of said electronic circuits connected to said corresponding one of said contact portions.

Claim 15

The combination according to claim 10 wherein said connecting means include a second pattern also deposited on said substrate and a second contact projection included in said conductive tongues, said second contact projection of said tongues being positioned over said second pattern, the depression of a key causing said second projection to contact said second pattern so that electrical current is conducted from said second pattern, through said second projection, aid contact tongue, said first projection and said first pattern to said chip.