Note: Descriptions are shown in the official language in which they were submitted.
1046;~01
BACKG~OUND OF THE INVENTION
The invention relates to a key for a cylinder lock with recesses
extended in the longitudinal direction of the key for the tumbler pins.
In known flat keys of this type the advantage exists that through
the extension extending from the position centre of the tumbler on either
side in the longitudinal direction of the key of the oblong recesses of the
90 lateral permutation milled into the flat sides of the key the position
of the tumbler pins on the lock i8 concealed,i.e. it is impossible to
determine the actual tumbler centre. In addition, the further advantage
is provided that due to the oblong recesses only made by milling and
which can have a different length, depth and width, unauthorised
duplication of the key becomes more difficult than if rounded recesses
drilled out of the key shank are provided for the cylindrical tumbler pins
engaging therein (Swiss Patent No, 260, 517).
lS It is conventional with flat keys of this type to provide in
addition to the preferably cylindrical tumbler pins which laterally
engage in the oblong milled recesses o the 90 lateral permutation,
i, e, the so-called "lateral steps" on the flat sides of the key, others
on the narrow side of the key which engage in drilled rounded recesses.
The radial reception bores of the locking cylinder for the edge tumblers
associated with these so-called "edge steps" generally have the same
lengthwise spacing from the front of the cylinder as the reception bores
for the lateral tumblers of the 90 lateral permuta~ion associated with
the lateral steps, i, e. they are both arranged in the same grid in order
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thereby to permit more rational tool utilisation. Thus, in accordance
with the selected overall permutation, bores for lateral tumblers and
bores for edge tumblers can be provided in the locking cylinder in in
each case common planes which are perpendicular to the cylinder axis.
Thus, the recesses made on the flat key as lateral and edge steps have
in pairs always the same longitudinal spacings from the key stop with
reference to their position centre for the associated tumbler pin.
In this case the lateral steps of the flat key only assume the function
o identification between key and locking cylinder because they are
extended in the longitudinal direction of the key on either side from the
position centre of the associated tumbler, whereas the edge steps made
in the form of countersunk holes fulfil the function of limiting longitudinal
pulling of the inserted key together with that of identification,
However, with these known flat keys there is the disadvantage
that if after starting to turn the key, pulling takes place thereon during
the further rotation of the rotorJ the tumbler pins engaged in the edge
steps of the key immediately start to ascend the 45 side of these
conical edge bores and are raised until the head thereof strikes against
the wall of t}~e rotor reception bore in the stator, whereas the tumbler
pins of the 90 lateral permutation milled into the lateral steps of the key
extended on either side remain on the base of the elongated recess.
Thus, during the rotation of the rotor the tumbler pins of the edge
tumblers mounted therein can penetrate the stator bores of the 90
lateral tumblers which are passing over,( relative to the rotating rotor),
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i, e, engage in "extraneous" stator bores so that the further rotation of
rotor and key is locked.
This so-called "hanging up" of tumbler pins of the additional
permutation in "extraneous" stator bores can in principle also occur
for the same reasons if on the flat sides of the key in addition to the
oblong milled recesses of the 90 lateral permutation additional recesses
are provided for the tumbler pins of a 45 additional permutation inclined
by an angle of 45 relative to the key side face, whereby here yet again
the radial reception bores of the locking cylinder for the 90 lateral
tumblers and those for the tumblers of the 45 additional permutation
are arranged pairwise in common planes perpendicular to the cylinder
axis. The reason is that here again if the key is pulled shortly after
the start of turning of the key the tumbler pins of one row of steps of
the 45 additional permutation can "hang up" in a passing row of stator
bores of the 90 lateral tumblers on rotating the rotor to a rotation
po~ition of 45 based on its initial rotation position. This is because
the tumbler pins of the 45 lateral permutation which exercise the
function of limiting the longitudinal travel of the key are displaced outwards
during rotor rotation by the side pressure of the non-extended, i. e.
only conically drilled recesses of the 45 degree additional permutation
exerted due to the pulling of the key on its conical tips. Thus, the pin
heads engage under pressure against the wall of the rotor reception bore
and consequently on further rotating the rotor "wait" to engage in passing
"extraneous" stator bores.
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A further disadvantage of the known flat key in which
only the additional recesses constructed as countersunk holes, no
matter whether these are constructed only as edqe steps or also
as 45 lateral steps, assume the function of limiting longitudinal
pulling of the inserted key is that through premature pulling on
the key during rotor rotation i.e. when they are exerting their
longitudinal pull limiting function, and also through any "hanging
up" in "extraneous" stator bores, the associated tumbler pins are
subject to much more wear than the tumbler pins of the 90 lateral
permutation which engage only in the lateral steps of the flat
key extended on either side and only exerting an identification
function and therefore only serve for identification between key
and locking cylinder. This disadvantage is particularly important
because it is this weakest type of tumbler which must assume the
1 longitudinal pull limiting function, i.e. the tumblers of the
? additional permutations often have a smaller diameter for con-
3 structional or space-saving reasons that the tumblers of the 90
lateral permutation.
The present invention removes these disadvantages.
According to the invention there is provided a key of
the type defined hereinbefore, wherein at least one recess of the
key is extended from its tumbler centre in the direction of the
key stop on one side only andlthe recess side located on the
recess end facing the key tip and serving as a slide for the
associated tumbler pin is at the same time a supporting side for
i limiting longitudinal pulling of the key.
According to the present invention therefore there is
provided a key for use in combination with a cylinder lock of the
type having a bore and a movable portion rotatable in said bore
to operate the lock, a substantially rectangular key slot in the
¦ movable portion, and a plurality of tumbler pins carried by said
movable portion and protruding into said key slot, the key com-
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prising an e'ongated blade portion insertable into said key slot,
said blade portion having a substantially rectangular cross
section with substantially flat sides having a transverse width
significantly greater than the diameters of said tumbler pins, a
handle portion, means for defining a fully inserted key position,
means in one of said sides of said blade portion defining a
plurality of longitudinally spaced elongated recesses for receiv-
ing the distal ends of said pins, each of said recesses having a
j longitudinal dimension significantly greater than the distal ends
of said pins, each of said recesses being located along said
blade in a position to receive one of said pins when said key is
I in said fully inserted position, the means defining at least one
~ of said recesses being located so that, in said fully inserted:~ position, the pin associated with said at least one recess is
received by said recess adjacent the end thereof farthest from
! said handle portion whereby the bore of said lock limits the
3 extent of movement of said pin associated with said at least one
recess away from said recess upon longitudinal movement of said
blade, when said movable portion is moved away from its key with-
drawal position, and the engagement of said pin with the end of
; said recess limits longitudinal motion of said blade portion.
¦ The present invention will be further illustrated by way of the accompanying drawings in which:
Fig. 1, a cut-away portion of a conventional flat key
according to Fig. 3 in a longitudinal section along the line I-I
3 of Fig. 3;
Fig. 2, the extension according to Fig. 1 extended on
both sides in plan view;
Fig. 3, a conventional flat key with recesses of the 90
, 30 lateral permutation extended on both sides and edge steps of an
! additional edge permutation in the removal position and in side
view;
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Fig. 4, the flat key according to Fig. 3 in a plan view
of one of its two narrow sides following the arrow IV of Fig. 3;
Fig. 5, the inserted flat key of Fig. 3 in the insertion
or removal position in a cross-section of the locking cylinder
' alon~ the line V-V of Fig. 3;
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Fig. 6, an inserted conventional flat key with recesses of
a 90 lateral permutation and a 45 additional permutation
in the removal position in a front view of the locking cylinder;
Fig. 7, the flat key according to fig. 6 following a 45 rotation
in a front view of the locking cylinder;
Fig. 8, a cut-away portion of the flat key according to the
invention and fig. 10 in longitudinal section along the line
VIII-VIII of fig. 10;
Fig, 9, a recess according to fig. 8 extended on one side in
plan view;
Fig. 10, a flat key according to the invention with recesses
of the 90 lateral permutation extended only on one side
in side view;
Fig, 11, the flat key of fig. 10 in a plan view of one of its two
narrow sides following the arrow XI of fig, 10;
Fig. 12, a flat key according to the invention with a row of
recesses of the 90 lateral permutation extended on one side
and made by the continuous path milling process ina plan
view on one of its narrow sides partly in longitudinal section;
Fig. 13, an inserted flat key accordîng to the invention with
the recesses of a 90 lateral permutation and a 45 additional
permutation after rotating the rotor from its initial rotation
position into a first state of the longitudinal pull limitation
process in a longitudinal section through key and stator;
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Fig. 14, a flat key according to fig, 13 in the terminal
state of the longitudinal pull limitation process in longitudinal
section through key and stator.
DETAILE~D DESCRIPTION OF THE PREFERRED EMBODIMENTS
In fig. 1 which shows a longitudinal section of a cut-away
portion of a conventional flat key lk according to fig, 3, is represented
one of the oblong recesses 2k of the 90 lateral permutation milled
in the key shank on both flat sides of the key. From its tumbler centre
Z the recess 2k is extended on either side in ~he longitudinal direction
of the key, i, e, in this case by the same amount v to both sides and
therefore symmetrically, Thus the here cylindrical tumbler pin 3
with the sides 4 of its conical tip 5 engaged in the recess 2k of the
inserted key lk is equi-distant from the two ends 6 of the oblong recess
2k ~cf, also fig, 3), i. e. recesses 2k in this case only fulfil the function
of identification between key and locking cylinder, whereas the edge
recesses 7 of flat key lk constructed as countersunk holes and which
form an additional permutation on said key (cf. fig. 3), serve both to
identify and limit the longitudinal travel of the flàt key turned from its
removal rotation position as will be explained in greater detail relative
to fig. 3, Due to the two-sided extension of recess 2k the actual position
centre Z of tumbler pin 3 and therefore the pGsitiOn of the tumbler on the
lock is concealed which makes it much more difficult to illegally duplicate
the key, ~he two recess sides 6 are inclined at an angle ~ of 45
relative to the base 8 of the recess and therefore also relative to key
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surface 22 and consequently they form 45 slides for the 90 conical
tip 5 of tumbler pin 3 when key lk is inserted in the rotor of the locking
cylinder or is removed therefrom, Fig, 1 shows by means of the dotted
lines which position a tumbler pin 3 can assume on insertion of key lk
immediately following the engagement in recess 2k or when the key is
removed in the direction of arrow Sz immediately prior to the ascent
on the other 45 slide 6.
It can be gathered from fig. 2 which shows the recess 2k in
plan view that also the base 8 of the recess on which rests the engaged
tumbler pin 3 with its somewhat flattened conical tip 5 is extended
equi-distantly to either side from the tumbler centre Z in the longitudinal
direction of the key.
Fig. 3 shows the conventional flat key lk in its removal
rotation position inserted in cylinder lock 9 only partly shown here
in longitudinal section, whereby the stop face 17 of said key lk engages
with the front face of the rotor. The necessary longitudinal pulling
limitation of key lk is here brought about by the edge recesses 7 and
iB brought about in that if initially, i. e, during turning of key and rotor,
the key is pulled, the tumbler pin 10 shown in fig. 3 and belonging to
one of the edge tumblers at the start of pulling on the key immediately
starts to ascend via its conical tip the 45 side of the conical edge
bore 7 facing the tip of the key and thereby abuts with its head 12 against
the wall 13 of the receiving bore of stator 14 for rotor 15 so that the
further ascent of tumbler pin 10 out of edge recess 7 is prevented, thereby
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making premature key removal impossible,( cf. also fig. 5 ).
It can also be gathered from figs 3 and 5 that the edge tumblers
of cylinder lock 9 associated with the edge recesses 7 of flat key lk
and the tumblers of one of the rows of tumblers for the 90 lateral
permutation arranged on either side of key channel 18 (cf. fig. 5) and
associated with the oblong recesses 2k are located pairwise in common
planes perpendicular to the cylinder axis and this obviously applies to
the associated radial recess bores of the relevant tumblers in the stator
14 and rotor 15. Thus, if key lk is pulled after the start of rotor rotation,
the tumbler pins 10 of the edge tumblers engaged in the edge recesses 7,
particularly in view of the fact that their diameter is generally smaller
than that of the tumbler pins 3 of the 90 lateral tumblers, can penetrate
passing radial stator bores 16 for the 90 lateral tumblers on further
rotation of rotor 15 (cf. fig. 5), i. e. to some extend "hang up" in bores
of an "extraneous" stator bore row. This undesired phenomenon occurs
because the edge tumbler pins 10, as already stated relative to the
limitation of longitudinal pulling of the key, during rotor rotation are
raised to such an extent from the 45 side of the conical edge bore 7
due to longitudinal pulling on the key until their head 12 engages under
pressure with the wall 1~ of the rotor reception bore in stator 14, whereby
on further rotation of rotor 15 they "wait" to penetrate the next passing
"extraneous" stator bore 16. Further rotation of rotor and key are
blocked by this undesired "hanging up" of the edge tumbler pins 10
on "extraneous" stator bores 16 of the 90 lateral tumblers.
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It can be gathered fro~n fig. 4 which shows the flat key lk
according to fig. 3 in a plan view of one of its two narr~w sides that,
corresponding to the tumbler drilling design on the lock cylinder 9, also
on flat key lk the edge recesses 7 and the oblong recesses 2k arranged
in a longitudinal row on one of the two flat sides of the key pairwise in
each case have the same longitudinal spacings al or a2 from the key
stop face 17, with reference to their position centre for the associated
tumbler pin 3 or 10 (cf. figs. 3 and 5), whereas the other longitudinal
row of oblong recesses 2k (i. e. the upper row in fig. 4) is staggered
relative to the first row in the case of the same longitudinal grid, as
in the case of this row in the longitudinal direction of the key relative
to key stop 17. As in this case flat key lk is constructed as a turning
key with a double recess design, it has two longitudinal rows of recesses
2k on each of its two flat sides, whereby with the key inserted one of these
rows (in figs. 3 and 5 the upper row) forms the so-called "active" row
and the other row (in figs. 3 and 5 the lower row) forms the so-called
"passive" row.
Fig, 5 shows a cross-section of the locking cylinder 9 with the
nat key lk according to figs, 3 and 4 inserted in the key channel 18 of
rotor 15 in the insertion or removal rotation position of rotor and key.
It is clear here that if the key is pulled in the direction of arrow Sd during
rotation of the key, the edge tumbler pins 10 following a 90 rotation of
key and rotor from the initial rotation position shown in fig. 5 can
"hang up" in the radial stator bores 16 of the row of stator bores of the
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90 lateral tumblers shown to the right in fig. 5,
In fig. 6 which shows a locking cylinder 9 in front view an
in~erted conventional flat key lk with two rows of recesses of a 90
lateral permutation is also provided with two additional permutations
in each case at an angle of 45 relative to the key surface 2Z. The
recesses of the 90 lateral permutation are extended on either side of
the longitudinal direction of the key from the position centre of the tumbler
thereof, whereas the recesses of the 45 additional permutation are
constructed as inclined countersunk holes, The flat key lk which in
fig, 6 i6 broken off at the shank shoulder, i, e. is represented in cross-
section, is located in its insertion or removal rotary position in which
the radial bores of the four rows of bores I, II, III and IV of rotor 15
are coaxially aligned with the associated radial bores of the associated
and IVs
row of the four bore rows Is, IIs, IIIs/of stator 14. The tumblers of
the 90 lateral permutation in rows I/Is and the tumblers of the 45
additional permutation in rows II/IIs to the right of key channel 18 are
positioned pairwise in common planes perpendicular to the axis of locking
cylinder 9. To the left of key channel 18 the tumblers of the 90 lateral
permutation in rows IV/IVs and the tumblers of the 45 additional
permutation in rows III/ILIs are also located pairwise in common planes
perpendicular to the cylinder axis but which are staggered relative to the
first-mentioned planes to the right of key channel 18 in the axial direction
of locking cylinder 9. Thus, when the key lk is turned in the direction of
arrow Sd from its initial rotation position shown in fig. 6, whereby
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simultaneously the key is pulled, this once again leads to a "hanging up"
of the tumbler pins mounted in rotor 15 on "extraneous" stator bores,
as will be explained hereinafter relative to fig. 7.
According to fig. 7 the flat key lk which can be constructed
like the flat key of fig. 3 as a turning key with a double recess design
is turned from its insertion rotation position (cf. fig. 6) in the direction
of arrow Sd, whereby the radial tumbler bores of the rotor bore row II
pass over those of stator bore row Is. If pulling takes place on key lk
during said key rotation in the direction of arrow Sd, i. e. shortly after
the start of rotation, immediately pulling on the key commences the
tumbler pins of the 45 additional permutation located in rotor bore row II
are displaced outwardly in their rotor bores and pressed against the wall
13 of the rotor reception bore in stator 14 because the associated recesses
of the 45 additional permutation drilled into the shank of flat key lk
lS immediately raise, i. e. displace outwardly the conical tips of the
tumbler pins engaged in these recesses with the side thereof immediately
pulling on the key commences. Thus these tumbler pins can penetrate
the passing over radial stator bores of stator bore row Is when passing
said row Is on rotating rotor 15 by a rotation angle of 45 (cf. figs. 6 and 7),
particularly as the diameter of the tumblers of the 45 additional
permutation can be smaller than the diameter of the tumblers of the 90
lateral permutation, whereby its diameter is also smaller than the stator
bores located in stator bore row Is for the so-called locWng pins, upper
pins or counter-tumblers of the pairs of tumbler pins of the 90 lateral
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permutation. However, if "hanging up" o "extraneous" stator bores
'~rnpo~S;~C~
actually occurs it is here again ~e to further rotate the key lk
During the previously described key and rotor rotation in the
direction of arrow Sd the radial bores of rotor bore row IV simultaneously
pass those of the stator bore row IIIs (cf. fig, 7), The tumbler pins of
the 90 lateral permutation in row IV could thereby penetrate the
passing bores of row IIIs of the 45 additional permutation so that once
again there is a danger of "hanging up" in "extraneous" stator bores.
In fig, 8 it shows a cut-away portion of the key 1 according to
fig, 10 according to the invention here constructed a s a flat key, one
of the oblong recesses 2 of the 90 lateral permutation milled into the
key shank on the two flat sides of the key is represented in longitudinal
section and it is in fact the recess 2 which in fig. 10 is located in the
upper row of recesses in the vicinity of key tip 11. From its tumbler
IS centre Z recess 2 is extended in only one side in the longitudinal direction
of the key, namely in the direction of the key stop face 7 by a quantity v.
The recess side 6 located at the end of recess 2 which faces key tip 11
(cf. fig. 10) forms a slide inclined at an angle ~ of 45 relative to key
surface 22 for the tumbler pin 3 to be raised from recess 2 in the
direction of arrow Sz and removing the key, and at the same time also
forms a supporting side for longitudinal pulling limitation of the inserted
key 1 but which has already been turned from its initial rotation position.
In the situation shown in fig. 8 the here, for example, cylindrical tumbler
pin 3 inserted in oblong rece6s 2 engage~ with the 45 6ide 4 of its conical
tip on the bearing recess side 6 which limits longitudinal pulling of the key
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so that during the rotation of the rotor from its initial rotation position
recess 2 exerts its longitudinal pull limitation function in the direction
of arrow Sz in the case of premature pulling on key 1.
As recess 2 is extended in the longitudinal direction of the key,
its tumbler centre or the associated tumbler pin 3 engaging therein is
assumed or simulated at another point~ namely at the point Zv in the
centre of oblong recess 2, whereas its actual tumbler centre for the
associated tumbler pin 3 or the associated 90 lateral tumbler comprising
a pair of pins is at a point Z in the vicinity of the bearing recess side 6,
as is shown in fig. 8, by tumbler pin 3 represented by continuous lines.
The assumed or simulated tumbler centre Zv is indicated in fig. 8 by
a tumbler pin 3 located at point Zv and designated by dot-dash lines,
whereas to the right thereof is shown a tumbler pin 3 still resting on
key surface 22 prior to its insertion in recess 2, said pin being designated
by dotted lines. The tumbler pin 3 to the right in fig. 8 at the same time
illustrates that the one-sided extension of recess 2, i. e. its extension
quantity v can be dimensioned in such a way that there is still sufficient
space for a smallest step value of the 90 lateral permutation following
in the same recess row in the direction of key stop 17 (cf. fig. 10),
whereby the associated tumbler pin 3 rests on key surface 22,
When key 1 is inserted in the key channel of the lock rotor in
the opposite direction to arrow Sz, the tumbler pin 3 slides on the other
recess side facing key stop face 17(cf, fig. 10) which also forms a slide
for the tumbler pin 3 inclined by 45 to the key surface 22 and in fact
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slides down to the base 8 of recess 2,
Fig, 9 shows a plan view of the recess 2 according to fig. 8
extended from its tumbler centre Z on only one side in the direction of
key stop face 17 (cf. fig. 10). Fig. 9 shows also the bearing recess side
6 limiting the longitudinal pulling of the key at the end of oblong recess 2
facing key tip 11 (cf, fig. 10), together with the actual tumbler centre Z
for the engaged associated tumbler pin 3, together with the simulated
tumbler centre Zv in the centre of the oblong recess 2, This drawing
also shows the extension quantity v of recess 2 extending from the actual
tumbler centre Z in the direction of key stop face 17, together with the
correspondingly extended base 8 of the recess,
Fig, 10 shows in side view the flat key according to the invention
here constructed as a turning key with a double recess design, The
oblong recesses 2 of the upper row of recesses are in each case only
extended on one side in the direction of the key stop face 17 from their
tumbler centre Z so that the recess sides 6 which form the 45 slides
for the associated tumbler pins facing the key tip 11 as supporting sides
also assume the function of longitudinal pulling limitation of key 1
(cf. also fig. 11~. Thus if during the rotation of the inserted key 1, it
is pulled in the direction of arrow Sz the tumbler pins engaged in the
recesses 2 of the 90 lateral permutation ascend the bearing recess sides
6 inclined by 45 to the key surface 22 as soon as pulling on the key 1
begins, whereby they strike against the wall of the rotor reception bore
in the stator and thereby prevent premature longitudinal pulling of key 1
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whereas any additional recesses for edge tumblers or for tumblers
of a 45 additional permutation (not sh~w n in fig. 10) are positioned and
extended in such a way in the longitudinal direction of key 1 that in the
case of longitudinal pulling limitation of key 1 the tumbler pins engaged
in the additional key recesses do not ascend the recess sides thereof,
i. e, lose their function of longitudinal pull limitation for key 1, i, e,
they are relieved, This is shown in figs. 13 and 14 and will be explained
in greater detail hereinafter.
It must be remembered that in the case of the turning key
1 according to fig. 10 only the recesses 2 of one row of recesses, i, e,
the upper row in fig. 10 is extended from its tumbler centre Z up to the
key stop face 17 or end portion 21 whereas the recesses 2a of the other
row of recesses, i, e, the lower row in fig. 10, are extended from their
tumbler centres Z in the opposite direction to key tip 11, so that the
oblong recesses 2a of the lower row on assuming their identification
function between key and locking cylinder in the form of so-called "active"
recesses in the appropriate insertion rotation position of turning key 1
exert no longitudinal pull limitation function for key lc These opposite
recess extensions in the two rows of recesses 2 and 2a are obtained
when recesses 2 and 2a are produced by a continuous path milling process
as described in Swiss Patent No, (Application No,
BE 16745) and will briefly be explained hereinafter relative to fig, 12,
On the other flat side of turning key 1 not visible in fig, 10, these so-called
"recess tails" emanating from tumbler centre Z are positioned analogously
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relative to the two rows 2 and 2a in accordance with the continuous path
milling process,
Fig, 11 shows a plan view of the upper narrow side of the
turning key 1 of fig, 10, By means of the tumbler pins 3 engaged in the
oblong recesses 2 and the lateral engagement of their conical tips on the
supporting reces~ side 6 facing key tip 11, a better illustration is provided
of how the recesses 2 exercise their function of longitudinal pulling
limitation for key 1, although they are extended in the longitudinal
direction of the key in order to conceal their tumbler centres Z,
whereas on the other key flat side (the upper side in fig, 11), the recesses
of the longitudinal row of recesses do not fulfil this function, i, e, as
"active" recesses they merely serve for purposes of identification
between key and locking cylinder.
Fig, 12 shows a flat key 1 according to the invention with a
row of recesses 2 of the 90 lateral permutation in each case extending
only on one side from their tumbler centre Z in the direction of the key
stop face 17 or the end portion 21 produced in the continuous path milling
process, in plan view on a narrow side of key 1, partly in longitudinal
section, The sides6 of the oblong milled recesses 2 serving as 45
slides for the here cylindrical tumbler pins 3 and facing key tip 11 are
at the same time supporting sides for longitudinal pulling limitation of
the inserted flat key 1 which has, however, already been turned somewhat
from the insertion rotation position for locking or unlocking purposes,
Furthermore, fig, 12 shows by means of dotted lines that the successive
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recesses 2 in the longitudinal row and having different step depths can
also be milled into the key shank in such a way that they pass into one
another. In the continuous path milling of the successive recesses 2
which in advantageous manner takes place in a single milling cutter
pass from end portion 21 to key tip 11, a cutter can be used whose
diameter, size and outer contour completely corresponds to tumbler
pin 3, i. e. need be no larger than said pin, as is necessary in the case
of the conventional milling process in view of the 45 slides for tumbler
pins 3 extendinK up to key surface 22 which have to be produced on the
two recess ends. The reason is that in the continuous path milling
process it is advantageously possible to select the largest step depth
of the recesses 2 quite independently of the diameter of the milling cutter
used in making the same. Thus, for example, in fig. 12 the recess 2
adjacent to end portion 21 has the largest step value of the 90 lateral
permutation. When making this deepest recess 2 in accordance with
the continuous path milling process, the cylindrical part of the cutter
is inserted into the flat key material to below key surface 22, whereby
it produces on the two longitudinal sides of recess 2 two planar lamellar
side portions 23 which are parallel to one another in the longitudinal
direction of the key, whilst being adjacent and perpendicular to the key
surface 22. Only one of these is shown in fig. 12. These two side
portions 23 are in no way prejudicial to the engaging movement of tumbler
pin 3 because on engaging the latter also enters recess 2 with its upper
cylindrical part, i. e. undercuts key surface 22 as clearly shown in fig. 12.
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Further advantages of the key produced by the continuous path milling
process or this fully automatic process used in making the same in which
the cutter completely copies the movement pattern of the tumbler pin 3
because it corresponds thereto completely as regards shape and travel,
are described in Swiss Patent No. (Application No.
= BE 16745).
Fig. 13 shows a cut-away view of an inserted flat key 1
according to the invention with the recesses of a 90 lateral permutation
and with the recesses inclined at 45 to the key surface 2Z of a 45
additional permutation and specifically after rotating the rotor (not
shown in fig. 13) from its initial rotation position into a first state of
the longitudinal pull limitation process in the case of premature pulling
on key 1 in the direction of arrow Sz, in the present case in the form of
a longitudinal section through key 1 and stator 14 of the locking cylinder.
The in this case cylindrical tumbler pin 3 engaged in the oblong recess 2
of the 90 lateral permutation here engages with the side 4 of its conical
tip 5 on the longitudinal pull-limited side 6 of recess 2, whereby its head
12 is at a distance s3 from the wall 13 of the rotor reception bore in stator
14, i. e. from the cylindrical plane of separation between rotor and
stator 14. However, as opposed to this the tumbler pin Z5 engaged in
the recess 24 of the 45 additional permutation has still not engaged on
the end 6 of recess 24 via side 4 of its conical tip 5, but is instead at a
distance w25 therefrom, which corresponds to spacing s3. The reason
is that recess 24 of the 45 additional permutation is also drawn lengthwise
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1046301
in the key longitudinal direction, which can also be achieved in the
continuous path milling process by means of a separate cutter inclined
by 45 to the key surface Z2, whereby this takes place simultaneously
with the milling of the oblong recesses 2 of the 90 lateral permutation.
In fig. 13, recess Z4 of the 45 additional permutation which
has the same spacing as recess Z of the 90 lateral permutation from
the key stop face is not shown for reasons of clarity. Instead, the next
recess 24 of the same additional recess row in the direction of the key
stop face is shown, but which with reference to the movement sequence
during the longitudinal pulling limitation process can be considered in
the same way as recess Z4 of the 45 additional permutation which is
at the same distance from the key stop face as recess 2.
Fig. 14 shows the inserted flat key 1 according to fig. 3 in a
second state, i. e. the final state of the longitudinal pull limitation process.In fig. 14 the key 1 which has been turned somewhat from its insertion
rotation position, which in fig. 13 was slightly withdrawn from the key
channel in the direction of arrow Sz accompanied by the elimination of
its side tolerance on tumbler pin 3 until end 6 of recess 2 engaged on side
4 of conical tip 5, is removed somewhat further from the key channel
through further tension on the key in the direction of arrow Sz by a
relatively small amount w, corresponding to spacing s3, i. e. sufficiently
far for the tumbler pin 3 ascending the end 6 of recess 2 accompanied by
the elimination of spacing s3, strikes by means of its head 12 the wall 13
of the rotor reception bore in the stator 14, which provides the necessary
104t;3~)1
longitudinal pull limitation for the inserted flat key 1, Admittedly at
this time the tumbler pin 25 of the 45 additional permutation also
engages the end 6 of its recess 24 with the side 4 of its conical ~ip 5,
but it nevertheless still rests on the base 8 of the recess so that its
head is removed from the wall 13 of the rotor reception bore in stator
14 by a spacing S25, whose size corresponds to spacing s3 (cf. fig. 13).
Thus, due to the spacing W25 in fig. 13 the recesses 24 of the 45
additional permutation, like the associated tumbler pins 25 are freed
from their longitudinal pull limitation function relative to key 1, i, e.
are relieved because only the recesses 2 of the 90 lateral permutation
assume the longitudinal pull limitation function although they are extended
in the longitudinal direction of the key as explained hereinbefore.
An essential advantage of the key according to the invention
is that in the case of premature pulling on the key which is still turning
with the rotor so-called "hanging up" of tumbler pins of the additional
permutation, no matter whether in the form of edge steps or as a 45
additional permutation, on the passing "extraneous" stator bores of the
90 additional permutation is reliably avoided, although the recesses
of the 90 lateral rotation are advantageously still`drawn lengthwise
to conceal the actual tumbler centre, i. e, the true position of the
associated tumblers onthe lock, whereby, however, at least one of these
recesses is extended on only one side from its tumbler centre to the key
stop face in order to form a suppGrting side for longitudinal pulling
limitation of the inserted key, A further advantage of the key is that
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10463~1
the additional recesses constructed as an edge or 45 additional
permutation now solely exercise the function of identification
between key and locking cylinder, i.e. they no longer perform
the hitherto additional exercised function of longitudinal
pulling limitation of the key so that the hitherto greater
stressing and wear of the tumbler pins of the edge or 45 addi-
tional permutation, on the weakest type of tumbler compared with
the tumblers of the 90 lateral permutation which greater stress
and wear results from the hitherto longitudinal pull limitation
and which also results for the undesired "hanging up" and which
appears as a locally increased wear, now is also avoided.
In the case of the key according to the invention, it
is by no means necessary for all the recesses of the 90 lateral
permutation to be extended only on one side from their tumbler
centre, i.e. being provided with a supporting side for longitu-
dinal pull limitation, because in principle this is in fact
ensured by the supporting side of a single recess of the 90
lateral permutation extended on one side accompanied by the
simultaneous freeing of the recesses of the additional permuta-
tion from the longitudinal pull limitation function. Thus inthe longitudinal rows of recesses of the 90 lateral permutation
it is also possible to provide a number of recesses extended
conventionally from the tumbler centre to both sides and which
are used merely for identification between key and
locking cylinder, whereby they can be of different length and/or
can be extended by a different amount from their tumbler centre, r
which further conceals the actual position of the tumblers on
the lock. However, for the purpose of uniform loading of the
key, in general each
r
104~301
of the two flat sides of the key, i. e. each row of recesses of the 90
lateral permutation is used for forming a longitudinal pull-limiting
supporting side, whereby preferably the recesses with the largest step
value (recess 2 to the far right in fig. 12) receive a bearing side for
longitudinal pulling limitation by means of an extension on one side.
The reason is that in the case of these deepest recesses of the 90
lateral permutation, the recess sides forming the 45 slides for the
tumbler pins are longer than in all the other recesses of this permutation
and are therefore particularly well suited for longitudinal pulling limitation
in view of the relatively large contact surface available for this purpose
with maximum side length. The selection of the recesses of the 90
lateral permutation to be extended on only one side ar.d therefore the
selection of the number and arrangement of the longitudinal pulling-
limiting supporting recess sides to be provided is largely determined
by the total permutation used as a basis for the locking cylinder or the
space conditions on the key shank resulting from the given recess pattern
of the particular key in quesSion, If, however, all the recesses of the
90 lateral permutation are always extended on only one side, i, e, are
provided with a longitudinal pulling-limiting supporting side, this has the
advantage that during manufacture of the key no particular account need
be taken as to whether the key recess provided with a bearing side for
longitudinal pulling limitation subsequently actually finds an associated
tumbler pin in the lock, i, e. whether it remains "blank". This precaution
is not in fact necessary if during key manufacture all the milled oblong
~04~3~1
recesses are fundamentally only extended on one side towards the key
stop face,
In the case of a flat key instead of longitudinal pulling limitation
thereof being exercised by the recesses of the 90 lateral permutation,
it could also be effected by the recesses of another random plane, as
is the case for example with keys with a radial arrangement of the tumbler
planes, Instead of permitting cylindrical tumbler pins to engage in
the key recesses, the latter could also have non-circular cross-sectional
shapes. Therefore, the invention is not limited to the embodiments
explained hereinbefore relative to the drawings and numerous variants
are possible thereto without passing beyond the scope of the invention.
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