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Claims  |
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I claim:
1. In a keyboard, actuatable with the aid of the tips of fingers of at
least one hand, which keyboard comprises a support frame, a first row of
key units, each of which comprises a key being movable out of an initial
inoperative position in which the tips of the index finger, middle finger,
ring finger and little finger, respectively, rest on the keys of said
first row, the keys of said first row for each hand to be used for
operating the keyboard being arranged on a curve, which corresponds to the
natural disposition of the finger-tips when the fingers are, without being
tensioned, in a slightly curved and spread, but relaxed posture, the
improvement of the key of each key unit of said first row having a key rod
and a top face on one end of said key rod and destined for having the tip
of a finger rest thereon, and, at the end of said key rod opposite said
top face, non-depressable mounting means articulatedly lodged in said
support frame and being adapted for preventing downward depression of said
key while permitting lateral shifting of said key toward at least one
determined operational position, thereby permitting random vertical
pressure to be exercised by a finger tip on said top face of a key of said
first row without causing operational displacement of the latter key, each
key unit of said guide key row further comprising:
(a) attracting means adjacent one side of said key, near the end of said
key rod bearing said top face and facing away from said operational
position, and adapted for exercising a determined initial attraction on
said top face-bearing key rod end opposing tilting movement of said key
away from said attracting means, when such movement is initiated by a
finger tip resting on the top face of said key; and
(b) stop means associated with said attracting means and preventing the
latter from following said tilting movement of said key, thereby
decreasing the attractive force of said attracting means as the distance
of said key therefrom increases due to progress of said lateral tilting
movement of said key, and thereby causing said finger tip to tilt said key
further until the latter is fully shifted to said operational position.
2. A key unit as described in claim 1, wherein said key rod is mounted is
said support frame, in a rest position at right angles to a bearing plane
of said support frame, and said unit further comprises at least one
contact switch having a stationary and a movable contactor, said key rod
bearing said movable contactor near the tiltable key-bearing end thereof,
an electrical operating circuit into which said switch is inserted, said
switch being opened in a rest position of the key without making contact,
thereby interrupting the flow of current through said operating circuit,
and being closable by movement of said key away from said rest position,
thereby making contact and thereby closing said operating circuit, and
said movable contact being so disposed on said key rod as to make
electrical contact when said key and key rod are tilted out of their rest
position by means of movement of the finger-tip.
3. A key unit as described in claim 2, comprising a plurality of said
contact switches about said key rod, and a guide device which permits said
key and key rod to be tilted only towards one of the stationary contactors
of said contact switches, said guide device comprising a screen which
surrounds the key rod and has cut-away portions, with each of which is
associated one of the directions of tilting of the key from its rest
position, so that the key can be moved into only one of these cut-away
portions each time for the purpose of making contact with a contact switch
associated with the cut-away portion concerned.
4. A key unit as described in claim 1, wherein said key rod is of
ferro-magnetic material, and said attracting means comprise a first
ferro-magnetic attracting element arranged substantially parallel to said
key rod, with opposite magnetic poles at the respective ends of said key
rod and of said first ferro-magnetic attracting element facing one
another, thereby establishing magnetic field lines attracting said key rod
and said attracting means in inoperative as well as in operative position
of said key.
5. A key unit as described in claim 4, further comprising
(a) an electric circuit having a contactor in said support frame facing the
side of said key rod away from said attracting means,
(b) conduit means extending through said support frame and said mounting
means lodged in the latter and ending at said key rod, and
(c) contact-making means associated with the top face-bearing end of said
key rod,
whereby said electric circuit is closed, when said key is tilted and
contact is established between said contactor and said contact-making
means.
6. A key unit as described in claim 5, wherein said contact-making means
comprise a second, electrically conductive attracting means lodged
intermediate said contactor and said key rod, and second stop means
associated with said second attracting means and preventing the latter
from following said key when said key is tilted out of its inoperative
position away from said contactor toward said first-mentioned attracting
means.
7. A key unit as described in claim 6, wherein said second attracting means
is a second ferro-magnetic element disposed substantially in parallel with
said key rod, with opposite magnetic poles of said second ferro-magnetic
element and of said key rod facing each other.
8. A key unit as described in claim 6, wherein said electric circuit
further comprises a second contactor in said support frame facing said
first-mentioned attracting means, the latter constituting a second
contact-making means in said electric circuit.
9. A key unit as described in claim 8, wherein said first and second
attracting means and their respective stop means are disposed on opposite
sides of said key rod, and which unit further comprises a third and a
fourth attracting means and third and fourth stop means respectively
associated therewith, said third and fourth attracting means and stop
means being disposed on opposite sides of said key rod, the latter sides
extending at a right angle to the sides of said key rod facing
respectively said first attracting means and first stop means, on one
hand, and said second attracting means and second stop means, on the other
hand, of said key rod.
10. A key unit as described in claim 1, wherein said mounting means
comprise a ball joint for mounting said key rod in said supporting frame
and an element for preventing the key rod from turning about its axis; or
a knuckle joint, said ball joint or knuckle joint being mounted on that
end of said key rod remote from said key.
11. An actuating unit as described in claim 1, further comprising a return
device for moving the key from an actuated position into the rest
position, the return movement of which device is initiated immediately
upon completion of contact-making by the key, even when the finger-tip
continues to exert tilting pressure, said return device comprising means
for limiting movement whereby the returned key is arrested and retained in
its rest position and prevented from passing through the latter in the
direction toward another contact.
12. An actuating unit as described in claim 11, wherein said return element
further comprises at least one pair of frames each having inner edges
defining a window which frames are fitted opposite each other for movement
in adjacent planes parallel to one another and surround the key rod, and
drive means for moving the two frames toward and superimposing one another
and comprising electric operating circuit means for causing said drive
means to operate immediately upon the completion of contact-making,
whereby when the key rod reaches its rest position, the frames bear
simultaneously with those of their inner edges facing the key rod on the
opposite sides of the latter to arrest said key rod in its rest position,
one of the two frames of the said pair being moved in a direction opposite
that in which the key has been moved for making contact, and the other
being simultaneously moved in the last-mentioned direction by the drive
means.
13. An actuating unit as described in claim 12, comprising at least one
pair of oppositely disposed contact switches between which the key rod is
centrally arranged, and two pairs of said frames, one pair of which frames
is associated with the two contact switches and is displaceable along the
line of movement passing through the two contact switches, whereas the
second pair are displaceable at an angle to said line of movement.
14. An actuating unit as described in claim 13, comprising two of the said
pairs of contact switches, there being associated with each of these pairs
of contact switches a pair of said frames, the respective lines of contact
which extends through the two pairs of contact switches forming a
right-angle with one another.
15. An actuating unit as described in claim 14, wherein said drive means
for moving the two frames of each pair of frames towards one another
comprise
(a) first electro-magnet means,
(b) a secondary circuit in said operating circuit wherein said
electro-magnet means is energized by the flow of current resulting from
closing of the respective contact switch,
(c) electrical switch means adapted for maintaining energization of said
electro-magnetic means, even after the respective contact switch has again
opened, until the respective key is fully returned to its rest position,
and
(d) second electro-magnetic means which is adapted to be energized when
return movement of the key is completed thereby causing the frames of said
pair of frames to move away from each other into their initial positions.
16. An actuating unit as described in claim 15, further comprising a
control element adapted for offering, to the finger-pressure, an initial
resistance which can be overcome by said pressure, but which, after having
been overcome, immediately decreases rapidly when the tilting movement of
said key begins, so that once the movement has been initiated it continues
in a positive manner until the respective contact is closed.
17. An actuating unit as described in claim 16, wherein each contact switch
present comprises a stator element and a tongue member mounted on the key
rod or on the support frame, a first stator element and tongue member,
being electrically insulated from ground and being connected to said
operating circuit, and a second stator element and tongue member being
grounded.
18. An actuating unit as described in claim 17 wherein said key rod is a
permanent magnet, one pole of which is adjacent the connection of said key
rod to the key and the other pole to said mounting of the key rod in the
supporting frame, and said tongue member is swingably mounted in the zone
of the last-mentioned pole on the key rod and has its own magnetism which
is of opposite pole to the magnetism of the key rod, so that the free end
of the tongue, in the rest position, forms a magnetic circuit with the
key-adjacent pole of the key rod which magnetic circuit is closed through
the connection of the tongue to the key rod mounting, said supporting
frame comprising a stop element which limits the movement of the free end
of the tongue towards the key-adjacent pole of the key rod, so that when
the key is moved out of its rest position away from the tongue member, the
latter cannot follow this movement whereby said magnetic circuit is broken
and the magnetic force of attraction between the free end of the tongue
and the key-adjacent pole on the key rod decreases rapidly.
19. A method of actuating a keyboard, actuatable with the aid of the tips
of fingers of at least one hand, which keyboard comprises a support frame,
a first row of key units, each of which comprises a key being movable out
of an initial inoperative position in which the tips of the index finger,
middle finger, ring finger and little finger, respectively, rest on the
keys of said first row and a hand rest for the ball of the thumb or wrist
of the said hand; the keys of said first row for each hand to be used for
operating the keyboard being arranged on a curve, which corresponds to the
natural disposition of the finger tips when the fingers are, without being
tensioned, in a slightly curved and spread, but relaxed posture, wherein
the key of each key unit of said guide key row has a key rod and a top
face on one end of said key rod and destined for having the tip of a
finger rest thereon, and, at the end of said rod opposite said top face,
non-depressable mounting means articulatedly lodged in said support frame
and being adapted for preventing downward depression of said key while
permitting lateral shifting of said key toward at least one determined
operational position, attracting means adjacent one side of said key, near
the end of said key rod bearing said top face and facing away from said
operational position, and adapted for exercising a determined initial
attraction on said top face-bearing key rod end opposing tilting movement
of said key away from said attracting means, when such movement is
initiated by a finger tip resting on the top face of said key; stop means
associated with said attracting means and preventing the latter from
following said tilting movement of said key, thereby decreasing the
attractive force of said attractive means as the distance of said key
therefrom increases due to progress of said lateral tilting movement of
said key, and thereby causing said finger tip to tilt said key
automatically further until the latter is fully shifted to said operating
position, and
(a) resting the said ball of the thumb or wrist of said hand on said hand
rest during actuation of the keyboard;
(b) exercising random vertical pressure by the finger tips on the top faces
of the keys of said first row,
(c) exercising tilting pressure by one finger tip on the top face of one of
said keys toward one of the forward, rearward, right or left sides
thereof, strong enough to overcome said initial attraction and tilting
said key;
(d) after return of said key and the finger tip thereon to the rest
position, exercising tilting pressure as described under (c) to the top
surface of the same or another key of said keyboard. |
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Claims |
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Description |
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This invention relates to a keyboard, actuatable with the aid of fingers of
at least one hand, which keyboard comprises a support frame, at least one
row of keys, each of which can be moved out of an initial unoperative
position by the tips of the index finger, middle finger, ring finger and
little finger, respectively, without or with a hand rest for the ball of
the thumb or wrist of the said hand, on which rest this hand can be
continuously supported in a rest position during actuation of the
keyboard, the keys in one row constituting a guide key row in which the
keys for each hand to be used for operating the keyboard are arranged on a
curve, which corresponds to the natural disposition of the finger-tips
when the finger are, without being tensioned, in a slightly curved and
spread, but relaxed posture.
Keyboards of the above type are known from German Pat. No. 1,279,693
(corresponding British Pat. No. 1,016,993) to International Business
Machines Corporation (IBM), IBM Technical Disclosure Bulletins on "Digital
X" Typewriter Keyboard" by D.L. Conway (Vol. 18, No. 12, May 1976) and on
"Input Keyboard" by P.E. Stuckert (Vol. 14, No. 3, August 1971) and from
German Offenlegungsschrift No. 22 18 065 to Georg Nawroth published Oct.
31, 1973. German Pat. No. 1,106,342 to Kuno Graf von der Schulenburg
published for opposition May 10, 1961 also describes a similarly arranged
keyboard in which the keys can be depressed for contact and also tilted.
Similar keyboards are described in U.S. Pat. No. 2,532,228 issued Nov. 28,
1950 to Frank H. Hesh.
An actuating unit somewhat resembling the unit used as key at least in the
guide key row of the keyboard according to this invention is shown in
FIGS. 2, 7 and 8 of U.S. Pat. No. 3,633,724 issued on Jan. 11, 1972 to
Ronald A. Samuel.
With the known keyboards of this kind, the hand, the fingers of which are
to actuate the keyboard, is normally held poised above the keyboard, with
constant strain on the muscles of the upper arm and, in particular, of the
fore-arm, and the tips of the operating fingers should either not rest at
all on the keys of a normal or guide row, or should only rest on them so
lightly that the keys are not actuated. The keys of modern typewriters and
similar machines, however, can be so finely set that even a very slight
pressure suffices to actuate them. With these modern machines it is not
possible to rest the fingertips truly on the keys, when not actuating
them, but only so much that, in particular, the muscles of the fore-arm
must still largely or completely provide the effort involved in keeping
the wrist continuously raised.
Furthermore, operation by touch, particularly on typewriters, requires that
the wrist of the hand, the fingers of which are actuating the keys, or the
wrists of both hands be held in, or continuously moved back to, a position
in which the actuating fingers are poised immediately above certain keys
of a normal or guide row of the keyboard so as to enable either the key
located below a finger-tip or a key positioned above, below or to the side
of that key, to be struck from this initial position without the lettering
on the keys having first been read. Therefore, with the known keyboards,
the entire "writing" procedure by actuation of the keys involves
considerable strain on all the muscles of the arm and corresponding mental
concentration simply for the purpose of continuously bringing the fingers
back to the initial position above the normal row of keys. This is
fatiguing and often leads to irritation of the nervous system and
discomfort to the wrist and fore-arm.
OBJECT AND SUMMARY OF THE INVENTION
A first object of the invention is therefore to provide a novel keyboard
which enables the actuating fingers of one or both hands so to rest at
random pressure on the keys in a normal or guide row, even when the keys
are not actuated, that the above-mentioned strain on the wrist and
fore-arm is considerably reduced or even completely avoided.
Another object of the invention is to provide an arrangement of novel keys
which can be operated with full mental concentration solely on the
decision which key to strike and on the initiation of the movement
necessary to carry this decision into effect while freeing the typist or
the like operating person completely from the mental concentration and
corresponding muscle control necessary to carry such movement to
completion and for the need thus to control the return movement of the
actuating finger to its rest position on the corresponding key of the
guide row.
A still further object of the invention is to provide a novel individual
key unit or actuating unit for the abovementioned keyboard, with which
unit the tip of the finger actuating the key can lie on the key at random
pressure in the rest position so that a rest element can be provided,
preferably, for the wrist as well.
A third object of the invention is to provide an actuating unit of the
last-mentioned kind for an individual actuating finger, with which unit,
not only one or two, but also a greater number of characters can be
written or fed in and printed out.
A further object of the invention is to provide a keyboard, particularly
for typewriters, which enables typing to be carried out more rapidly and
without the risk of several keys being simultaneously struck.
A final object of the invention is to provide a keyboard on which the
number of characters is considerably greater than in the corresponding
known machines, particularly typewriters.
In a keyboard of the initially described kind, these objects are achieved,
in accordance with the invention, by that the keyboard is characterized in
that each key of said guide key row has a top face and comprises at the
end thereof opposite said top face supporting means adapted for preventing
downward depression of said key while permitting lateral shifting of said
key toward at least one determined operational position, thereby
permitting random vertical pressure to be exercised by a finger tip on
said top face of a key of the guide key row without causing operational
displacement of the latter key.
Preferably, each key of said guide key row further comprises biassing means
adapted for offering initial resistance to lateral shifting movement of
said key, but decreasing said resistance as soon as the lateral shifting
movement of the key is in progress, thereby causing the shifting movement
to continue automatically till the key has been fully shifted to an
operating position.
Also, in a preferred embodiment of the keyboard or actuating unit according
to the invention, each key of at least said guide key row further
comprises guiding means for guiding said key in one or several
predetermined lateral shifting directions while preventing lateral
shifting of the key in directions intermediate said predetermined
directions.
Each key of at least said guide row preferably further comprises a
resetting device which is adapted for automatically returning the key from
a fully shifted first operational position to the unoperational rest
position and automatically preventing the returning key from passing
through said unoperational position and being shifted in a direction
toward an operational position, and, upon said key being arrested in the
unoperational position, setting the key free for further shifting to an
operational position.
The keyboard in accordance with the invention may also, in a known manner,
include at least one key which can be actuated by the thumb of the hand
whose fingers are operative, and which is arranged in a position relative
to the curve that corresponds to the natural untensioned position of the
thumb in the above-mentioned disposition of the finger-tips when the
fingers are held in untensioned position.
Furthermore, the keyboard in accordance with the invention may include a
second row of keys, which is disposed farther away from the hand rest than
the said normal row of keys and is located at a somwhat higher level than
the normal row, each of the keys of the second row being adjacent a key of
the normal row and being arranged at such distance from the key of the
normal row that, by slightly stretching the finger concerned, it can be
reached by the tip of this finger, thus actuating the corresponding key of
the second row, while the wrist is still supported on the rest.
An auxiliary key, which is disposed between the rest for the wrist and the
corresponding key of the normal row, can be associated with at least one
of the keys of the normal row.
In this arrangement, preferably at least one key of the normal row can be
swung from its rest position in a plurality of directions by the
finger-tip resting thereon, for actuaing the key concerned.
Thus, the swingable key in the normal row can be swung from its rest
position in any of four directions at right-angles to each other.
Also, at least one key of the second row can be tilted in a plurality of
directions by being touched by the tip of the finger when slightly
stretched from its rest position on that key of the normal row that is
associated with the said second-row key.
The tiltably key in the second row can be tilted preferably in any of three
directions, and one of the tilting movements of this key can be executed
by further stretching the finger concerned, and the other two by moving
the finger sideways to the right or left.
The above-mentioned auxiliary key can be disposed below, but not in contact
with, the middle joint of the finger concerned, which, in its rest
position, lies with its tip on the corresponding key in the normal row,
and said auxiliary key can be actuated by stretching the finger, thereby
lifting its tip from its key in the normal row, and by lowering or
laterally tilting the middle joint of the finger.
The hand rest can be arranged to be swung in a support frame towards one
side or towards opposite sides of the hand.
Preferably two rests are provided, one for the right hand and the other for
the left hand of the operator, and the curve on which the keys of the
normal row for the fingers of the left hand are arranged can be disposed
to form a mirror-image arrangement with the curve along which the keys of
the normal row for the fingers of the right hand are arranged.
The second and third of the above-mentioned objects are achieved by means
of a novel actuating unit for a keyboard in accordance with the invention,
which unit comprises a supporting frame, a key having a top face destined
for having the tip of a finger rest thereon, a key rod on the underside
thereof, a non-depressable mounting whereby said key rod is mounted in
said supporting frame and is disposed in a rest position at right angles
to a bearing plane of said supporting frame, at least one contact switch
having a stationary and a movable contactor, the key rod bearing said
movable contactor near the tiltable key-bearing end thereof, an electrical
operating circuit into which said switch is inserted, the switch being
opened in a rest position of the key without making contact, thereby
interrupting the flow of current through said operating circuit, and being
closable by movement of the key away from its rest position, thereby
making contact and thereby closing the operating circuit, and the movable
contact being so disposed on the key rod as to make electrical contact
when said key and key rod are tilted out of their rest position by means
of movement of the finger-tip, wherein the mounting is adapted for
supporting random vertical pressure thereon by said finger-tip and
preventing the key rod from making electrical contact in the rest
position.
Preferably, the mounting means for mounting the key in the frame comprises
a ball joint for mounting said key rod in said supporting frame and an
element for preventing the key rod from turning about its axis; or a
knuckle joint, said ball joint or knuckle joint being mounted on that end
of said key rod remote from said key.
A plurality of the contact switches mentioned above can be provided about
the key rod, and a guide device which permits the key and key rod to be
tilted only towards one of the stationary contactors of the contact
switches, which guide device comprises a screen which surrounds the key
rod and has cut-away portions, with each of which is associated one of the
directions of tilting of the key from its rest position, so that the key
can be moved into only one of these cut-away portions each time for the
purpose of making contact with a contact switch associated with the
cut-away portion concerned.
Furthermore, a return device for moving the key from an actuating direction
into the rest position can be provided, the return movement of which
device is positively initiated immediately upon completion of
contact-making by the key, even when the finger-tip continues to exert
actuating pressure, and the return device can include means for limiting
movement whereby the positively returned key is retained in its rest
position.
In this arrangement, the return element can include at least one pair of
frames which are fitted opposite each other and surround the key rod, and
drive means for moving the two frames on to each other, which drive means
are caused to operate by the completion of contact-making, and, when the
key rod reaches its rest position, the frames bear simultaneously with
those of their inner edges facing the key rod on both sides of the latter,
thus arresting its return movement.
One of the two frames of the said pair can be moved in a direction opposite
that in which the key has been moved for making contact, and the other can
be simultaneously moved in the last-mentioned direction by the drive
means.
At least one pair of oppositely disposed contact switches, between which
the key rod is centrally arranged, and two pairs of frames can be
provided, one pair of which frames is associated with the two contact
switches and is displaceable along the line of movement passing through
the two contact switches, whereas the second pair are displaceable at an
angle to said line of movement.
Also, two of the said pairs of contact switches can be provided, and a pair
of frames can be associated with each of these pairs, the lines of contact
which extend through the two pairs of contact switches forming a
right-angle with each other.
The drive means for moving the two frames of each pair of frames towards
each other can comprise at least one first electro-magnetic device which
is energized in a secondary circuit of the operating circuit by the flow
of current resulting from closing of the contact switch, as well as an
electrical switch device whereby energization of the electro-magnetic
device is maintained, even after the contact switch has opened, until the
key is fully returned, and finally a second electro-magnetic device which
is energized when return of the key is completed and which causes the
frames of said pair of frames to move away from each other into their
initial positions.
Each contact switch present can include a stator element mounted in the
support frame, and of the stator element and key, one of these is
electrically insulated from earth and is connected to the operating
circuit, and the other is earthed, so that, when the key is moved from its
rest position towards the stator element, contact is made.
The key can incorporate a control element which offers, to the
finger-pressure, an initial resistance which can be overcome by said
pressure, but which, after having been overcome, immediately decreases
rapidly when the swinging movement begins, so that once the movement has
been initiated it continues in a positive manner until the contact is
closed.
Furthermore, each contact switch present can include a stator element
mounted in the support frame and a tongue member mounted on the key rod or
on the support frame, and of the stator element and tongue member, one of
these is electrically insulated from earth and is connected to the
operating circuit, and the other is earthed.
Finally, the key rod can be designed as a permanent magnet, one pole of
which is connected to the key and the other pole to the mounting of the
key rod in the supporting frame, so that the tongue member is swingably
mounted in the zone of the last-mentioned pole on the key rod and has its
own magnetism which is of opposite pole to the magnetism of the key rod,
so that the free end of the tongue, in the rest position, forms a magnetic
circuit with the pole of the key rod that is connected to the key, a stop
element being provided which limits the movement of the free end of the
tongue towards the pole of the key rod that is connected to the key, so
that when the key is moved out of its rest position away from the tongue
member, the latter cannot follow this movement, whereby the said magnetic
circuit is broken and the magnetic force of attraction between the free
end of the tongue and the pole on the key rod that is adjacent the key
decreases rapidly.
BRIEF DESCRIPTION OF THE DRAWINGS
Details of the invention will now be described by reference to a preferred
embodiment which is illustrated in the annexed drawings, wherein:
FIGS. 1a and 1b show the arrangement of a preferred form of the keyboard of
the invention in an electric typewriter having a housing specially
designed to accommodate this keyboard, and of these Figures:
FIG. 1a shows an oblique perspective view of this typewriter from the
front, and
FIG. 1b shows a sideview having a partially cut-away portion on the left
side of the typewriter;
FIG. 2 illustrates diagrammatically and in plan view a preferred form of
this keyboard;
FIGS. 3 and 4 are sectional views along the axis of an actuating unit in
accordance with the invention and for the keyboard shown in FIG. 2, and of
these Figures:
FIG. 3 shows this actuating unit in its rest position, and
FIG. 4 shows the unit in its actuated position;
FIG. 5 is a cross-section through the actuating unit of FIG. 4 along a
plane indicated by the numerals V--V in the latter Figure;
FIG. 6 illustrates diagrammatically a control circuit for an actuating unit
as shown in FIG. 3;
FIG. 7 illustrates a preferred form of the guide device for the actuating
unit, and, in cross-section, two actuating devices for the FIG. 2 keyboard
along a plane designated by the numerals VII--VII in FIG. 3;
FIG. 8 is a perspective view of part of the actuating device shown in FIG.
3;
FIG. 9 is a cross-section through the FIG. 3 actuating device along a plane
indicated by the numerals IX--IX in that Figure;
FIG. 10 is a perspective view of a form of the actuating unit for the
middle joint and
FIG. 10A is a perspective view of part of the same unit seen from the
opposite end;
FIGS. 11 and 12 illustrate diagrammatically a form of the return device in
accordance with the invention which comprises four catch-plates and which
is associated with a single actuating unit as illustrated in FIGS. 3 and
4, and of these Figures:
FIG. 11 illustrates the position of the four catchplates when the unit is
actuated and at the moment of commencement of the return action, and
FIG. 12 shows the four catch-plates at the moment of completion of the
return action and before the four plates have returned to their initial
position as shown in FIG. 8, the actuating unit being returned to its rest
position;
FIG. 13 is a plan view of the return device for the keyboard shown in FIG.
2, which device comprises two sets of catch-plates, the foreground part
being shown in perspective;
FIG. 14 shows a cross-section through the return device on the plane
designated by the numerals XIV--XIV in FIG. 13;
FIGS. 15 and 16 illustrate a known electro-magnetic actuating device for a
form of typewriter, the two electromagnets of which are connected into the
control circuit illustrated in FIG. 6, this actuating device having been
described in Swiss Patent Specification No. 425 839 in the name of George
Manus, and
FIGS. 17 to 20 constitute a diagrammatic illustration of the form of
electric typewriter marketed by Royal McBee Corporation, Port Chester,
N.Y., USA, and as described by them in their Swiss Pat. No. 353 021, and
of these Figures:
FIG. 17 is a perspective partial view,
FIG. 18 is a side view of a key and type unit,
FIG. 19 illustrates an associated electric circuit diagramm, and
FIG. 20 shows, in side view, a single unit from FIG. 18.
DETAILED DESCRIPTION OF THE EMBODIMENTS
The electric typewriter illustrated in FIGS. 1a and 1b includes a housing
1, a normal roller 2 with carriage-shifting means (not shown), a set of
type-blocks 3 and a cable 4 with a plug for connecting to the local
electric supply mains. Built into the front side 5 of the housing 1 is a
keyboard in accordance with the invention which comprises a left-hand
group of keys 6 and a right-hand group of keys 7, each of the two groups
consisting of: a plurality of actuating units each of which includes a key
of a first type 8, a second type 9 and a third type 10; a left and right
thumb key 11 and 12 respectively; and a left and right support 13 and 14
respectively for the wrists and/or thumb-balls.
The following symbols for indicating movement are used in the drawings:
movements in the plane of the paper,
movements at right-angles out of the plane of the paper and
perpendicular movements into the plane of the paper.
As shown in FIG. 2, each group of keys comprises: actuating units 8 of the
first type provided with keys, with each of which units four different
type levers can be moved and on which units the finger-tips can rest in
the initial position; actuating units 9 of the second type whereby three
different type lever | | |
