Note: Descriptions are shown in the official language in which they were submitted.
~153~03
The invention relates to a cylinder-lock with flat key according to
the generic concept of the main claim.
In known designs of this kind ~United States Patent 17 35 868), a dog
constituting a movable key bit is in the form of a double lever adapted to pivot
about an axis. The rear edge of the double lever projects laterally beyond the
wide side of the key and is curved convexly. In the terminal-insertion posi-
tion, this curved rear edge moves into engagement with a shoulder in the key-
channel, which causes one tip of the double lever to be displaced laterally of
the opposite wide side of the key, to enter the bore of an auxiliary tumbler and
lQ move the latter to a released position making it possible for the cylinder core
to rotate. Prom the production point of view, this solution has disadvantages,
more particularly because the double lever, which is a precision casting, is
relatively complex in shape. There are also considerable operational disadvan-
tages. Since the double lever, even in its basic setting, projects considerably
beyond one side of the key, it is impossible to stack a plurality of keys one on
top of the other in a flat position. There is also always a danger of the mov-
able bit swinging out when the key is put away and then being damaged. To this
extent, the key is not suitable for a key-ring. In order to achieve the re-
quired durability, the movable bit must be made of a material of considerable
2Q thickness. This, however, increases the size of the key and it is impossible to
keep it within the normal commercial dimensions. The result of this is that
many of the profiled grooves in the lateral surface of the key ~ust be omitted,
which impairs the reliability of the lock and narrows its usefulness in master-
key installations and centralized-lock installations. Furthermore, this known
design requires a widened key-channel to accommodate the movable key bit and
t~is w~dening must extend as far as the outlet end of the key-channel and is
l~cated on the s~ide from w~ch the control forces are applied to the movable bit.
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This reduces the resistance of the lock to manipulation by a tool inserted into
the key-channel. It also has the disadvantage that, even when the key is fully
inserted the movable bit may still be reached by a tool inserted into the un-
occupied part of the key-channel cross-section. Thus, even when a key having a
movable bit not matched to the corresponding cylinder-lock, is inserted for ex-
ample, one of smaller dimensions, the movable bit can be pivoted by such a tool
into a position corresponding to the release of the auxiliary tumbler. The se-
curity-value of the key is thus very low.
It is the purpose of the invention to provide a configuration of this
lQ kind such that the production of the key is simplified, it is more convenient to
use, and wherein when the key is inserted the movable bit cannot be displaced by
manipulating or lock-picking tools, in the direction of the auxiliary tumbler.
The invention provides a cylinder-lock having a flat key comprising a
shank having at least one profiled longitudinal groove extending from the end
thereof to accommodate a rib in the key-channel of the cylinder-lock said shank
including fixed key bits, adapted to index pin-tumblers in the cylinder-lock,
said key including in the area of the wide side of the shank an additional mov-
able key bit, said movab}e key bit being adapted to be controlled by a shoulder
in the key-channel such that when the key is inserted it induces an auxiliary
tumbler into a position which allows the cylinder core of the lock to be rotated,
said movable key bit comprising a rolling element movably retained within a
transverse opening in said shank located in the lateral wall of said profile
longitudinal groove, said rolling element having a diameter which is greater than
the thickness of the material of the shank in the vicinity of said opening such
that said rolling element at all times projects laterally beyond said opening on
at least one side.
This design provides a cylinder-lock, with flat key, of increased ser-
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1153~U3
viceability, simplified manufactureJ and greater securit~. The use of a rolling
element, for example a sphereJ as the movable key bit slmplifies productionJ
since this component is of simple geometrical design which can be producedJ at
no great CostJ with considerable precision and in graded dimensions. The rolling
effect ensuresJ in practiceJ that there will be no increase in friction during
insertion and removal of the key. Since there are no parts which can pivot out
of the wide side of the keyJ the key according to the invention is more easily
stored. There is little danger of wearJ even after long periods of use.
There is no need to dispense with any of the profiled grooves in the
key. The fact that the rolling element is arranged in the vicinity of a profiled
grooveJ and is larger in diameterJ in this areaJ than the thickness of keyJ
means that the projecting rib provided in the key-channel whichJ in known fa-
shionJ fits positively into the profiled groove in the key, performs a control-
ling function. The free transverse displaceability of the rolling element in the
key makes it possible to shift the rolling element into its operative position
over a very short distance.
In the fully inserted position of the keyJ the rolling element cannot
be shifted by any lock picking or manipulating toolsJ to achieve additional trans-
verse lift. Thus the effective lift of the rolling element cannot be influenced
2Q from the outside. The undulating pattern of the key-channel sectionJ made
possible by the transverse displaceability of the rolling elementJ produces a
certain monitoring scanning thereof as soon as the key is inserted. If the dia-
meter of the rolling element is too largeJ it cannot be passed through this un-
dulating section. Such a key is prevented from entering even before the rolling
element can reach its operative position at the auxiliary tumbler. On the
other handJ if the rolling element is too smallJ although the key would not be
prevented from enteringJ it would not shift the auxiliary tumbler into the in-
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dexed or released position and, because of its inaccessibility, it could not be
shifted furtherJ by the required amount, by an inserted manipulating tool.
The wave-shaped pattern optimizes the hidden position of the rolling
element. Even on the wide side of the key, opposite the profiled groove by which
the rolling element is controlled there is no linear path for inserting a mani-
pulating tool. In the fully inserted position of the key, the rolling element
lies fully upon the end-surface of the projecting zone, so that, in the longi-
tudinal direction of the key and the lock, it is possible to work to larger
tolerances, thus simplifying production, without impairing security. In this
connection, the length of the projecting zones preferably corresponds to the
diameter of the rolling element. The small size of possible rolling elements,
more particularly spheres, and the compact way in which they are fitted, makes it
possible even to provide several rolling elements in one key, without increasing
the size of the key. The special wave-shaped pattern permits simple production
by milling, so that instead of the usual linearly milled key-channel, only a par-
tial external area needs to be milled in wave-shape. Control of the auxiliary
tumbler by means of a detent and cam makes it possible to operate with small
transverse displacements. In this connection, the special configuration, mount-
ing, and method of operation of the detent and cam described herein is struc-
2Q turally advantageous, especially as regards maintaining the necessary accuracy.
Instead of a sphere, it would also be possible to use a cylindrical
rolling element, for example with a cambered end-face. Producing the wave-
s~aped pattern in the key-channel section with corresponding stationary pins,
arranged in the cylinder core, is not only advantageous from the production point
o~ v~ew, but also makes possible many simple variations in assembling the
cylinder-lock. Above all, it allows the wave-shaped pattern to be produced at
any~level in the key-channel. Flattsning the inner ends of such pins makes it
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1153~03
possible to use pins of which the remaining sections are larger in cross-section
than the internal width of the longitudinal profiled groove. Designing such
pins as mushroom head pins, which position themselves merely by abutment, again
greatly simplifies assembly and even makes it possible to change, at a later
date, to pins of a different length, for example. If it is desired to manage
with the smallest possible number of pins, this is achieved, as indicated, in
that the inner end of a pin is associated with a recess in the opposing channel-
wall. The entry and exit edges of the re~ess are then located, in relation to
the free internal edge-sections of the pin travelled over by the rolling ele-
ment, so that this internal dimension corresponds approximately to the diameter
of the rolling element running in this direction.
In the case of flat keys, it is known to include spheres. (United
States Patent 3,877,267~. In this case, however, the spheres are stationary
and serve merely to reduce wear in the key in the vicinity of the key bits
controlling the tumblers. Furthermore, they are exposed on only one side of
the key. This makes it impossible to apply a force, as in the case of the
invention, to the sphere on one wide side of the key, for the purpose of ob-
taining a control-force on the other wide side of the key, from the surface
of the sphere emerging therefrom.
A number of embodiments of the invention will be explained herein-
after by way of example only, in conjunction with the drawings attached hereto,
wherein:
Figure 1 is a view of the shank of a flat key before ~nsertion into
the relevant cylinder-lock according to a first embodiment;
Figure 2 is a horizontal section through the shank of the key in the
area of the bearing locations accommodating the spheres, showing a partially
sectioned cylinder-lock, also prior to insertion of the key;
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Figure 3 is a view similar to Figure 2, but with the flat key inserted;
Figure 4 is a greatly enlarged cross-section through the cylinder-lock
with the key not inserted~ in the area of an additional tumbler;
Figure 5 is a view similar to Figure 4, but with the key inserted and
the additional tumbler shifted into the release position;
Figure 6 is a cross-section through a cylinder-lock according to a
second embodiment, in which the sphere arranged in the shank of the key controls
the additional tumbler directly;
Figure 7 is a horizontal section through the cylinder-lock of Figure 6
lQ in the plane of the sphere;
Figure 8 is a cross-section through a cylinder-lock according to a
third embodiment, with the key not inserted, in which the flat key indexes the
tumbler pins by means of recesses arranged upon the wide side of the key;
Figure 9 is a view corresponding that of Figure 8, but with the key
inserted;
Figure 10 is a vertical section through the cylinder-lock in the plane
of the additional tumbler, with the key not inserted;
Figure 11 is a section corresponding to that shown in Figure 10, a
recess in the opposing wall of the channel being associated with the end of a
2a pin;
: Figure 12 is a cros-s-section, to a greatly enlarged scale, through the
shank of such a key which indexes the tumbler-pins by means of recesses located
on its wide sides;
Figure 13 is a plan view of Figure 12;
Figure 14 is a cross-section through a cylinder-lock according to a
~ourth emb;odiment, with the key inserted; and
Figure 15 is a vertical section through this cylinder-lock of Figure 4
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liS3~(13
in the plane of the additional tumbler.
Referring to Figures 1 to 5 the cylinder-lock has a profiled locking-
cylinder-housing 1, with a cylinder core 3 mounted rotatably in a bore 2 therein.
The core is in communication with, but does not rotate in relation to a hub 5
having a locking ward 4.
Cylinder 1 and core 3 have aligned bores 6, 7 (Figure 5) accommodating
tumbler-pins 8 consisting of core-pins 8' and housing-pins 8". A compression-
spring 9 urges the latter towards cylinder core 3.
Running in the longitudinal direction of, and within, the cylinder
core 3 is a key-channel 10 having lateral walls 11 and 12 which have projecting
ribs which define a cross-sectional profiling of the key-channel 10.
The cross-sectional profile of the key 13 is adapted to that of key-
channel 10, the key consisting of a bow 14 and a shank 15. One narrow edge of
the ~hank 15 comprises consecutive notches 16 of varying depths which co-operate
with tumbler-pins 8 and index them, when the key is inserted, in such a manner
that the junction between the core-pins 8' and the housing-pins 8" is level with
the cy~lindrical surface F of the cylinder core 3 - see Figure 5.
Located on the narrow edge of the shank 15 remote from notches 16, run-
ning at right angles thereto, in the vicinity of the upper, profiled longitudinal
2Q groove 17, are bearing bores 18 for the accommodation of movable key bits in
the form of spheres 19, these bores opening onto both wide sides S and Sl of the
ke~ shank. The spheres 19, the diameter of which is smaller than the thickness
o~ the key, are prevented from falling out of the bores in that the said bores
have shoulders just before the wide side Sl and are lightly peened on the oppo-
site side S. However, the spheres remain free to move.
The ri6 in the lateral channel-wall 11 level with the profiled longi-
tudinal groove 17 in the key 13, bears the reference numeral 20. In conjunction
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11~3903
with the opposite lateral wall 12 of the channel, this rib forms a wave-shaped
or undulating pattern, projecting zones Z alternating with recesses E. The width
of this undulating section corresponds to the diameter of the spheres 19, and
the length of the projecting zones Z correspond approximately to the diameter
of the spheres 19.
One end 21 of a detent 22 projects into the area of each recess E in
the lateral wall 12 of the channel. The detent is accommodated in a transver~e
slot 35 in the cylinder core 3 and is se~mental in shape, such that the curved
surface 23 thereof is located in the vicinity of the cylindrical surface F. The
detent 22, which is displaceable along this surface F, is retained by means of a
wire 25 running in the longitudinal direction of the core and carried in a
groove 24 in the surface of cylinder core 3. The wire crosses a recess 26 ~Fig-
ure 4) of larger cross-section in the detent 22, open towards the surface F.
The other end 27 of the detent 22 engages in a groove 28 in and addi-
tional tumbler 29 which moves in a radial bore 30 at right angles to the key-
channel 10 and is urged outwardly by a compression-spring 31. The groove 28 has
a sloping base 32 upon which the end 27 of detent 22 bears in such a manner that
the outer section of the tumbler 29, extending beyond the end 27, projects into
a recess 33 in cylinder housing 1.
2Q With the key not inserted, the tumbler pins 8 and the additional tum-
~lers 29 all prevent rotation of the core in the housing.
~hen the key 13 is inserted into the key-channel 10 the key-notches 16
index the tumbler pins 8 accordingly, and the spheres 19, arranged linearly one
behind the other, pass through the undulating section of the key-channel. The
projecting zones Z in the lateral wall 11 of the key-channel enter the groove 17
in the key 13 and urge spheres 19 outwardly, causing them to project beyond ad-
jacent wide side S of the key. The spheres thus act upon the detents 22 which
1153gO3
are moved from the position shown in Figure 4 to that shown in Figure 5. This
causes the ends 27 facing the tumblers 29 to move the tumblers into the unlocking
position, i.e. out of the areas of recesses 33 in the cylinder-housing, thus
allowing cylinder core 3 to rotate. When the key is removed, the compression
springs 31 return the tumblers 29 and detents 22 to their starting positions,
shown in Figure 4.
The key 13 cannot be inserted into the cylinder-lock unless the key-
channel thereof has a profiled longitudinal groove of the required undulating
pattern in the vicinity of the spheres. If, on the other hand, a key without any
spheres is inserted, although it can index the tumbler-pins 8, it will not shift
the additional tumblers 29.
The recesses 33 in the cylinder housing are closed off by filler
pieces 34.
Instead of the additional tumblers 29 being provided on only one side
they could also be provided on both sides of the cylinder core in a staggered
arrangement.
In the embodiment illustrated in Figures 6 and 7, bearing bores 18 for
the accommodation of spheres 19, are located at the edges of a key 35 adjacent
the notches. The arrangement is such that, with key 35 inserted, as shown in
2Q Figure 6 the spheres 19 lie in the horizontal longitudinal centre plane of the
cylinder core 3. A rib 20', on the corresponding lateral wall of the channel,
projects partly into the groove 17' in the key 35.
Pacing the pins 36 are additional pins 37 which are staggered in re-
lation thereto. Free ends 37' of the pins 37 enter the key-channel 10'. The
distance ~etween the ends 37' and the opposing surface of the rib 20' corres-
ponds to the diameter of the spheres 19 and largers spheres cannot therefore
pass through the key~channel 10'. Thus the pins 36, 37 also define an undulat-
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ing section of key-channel.
Arranged in opposed alignment to the pins 36 are additional tumblers
38 equipped with stepped shanks 38' and projecting into the key-channel 10'.
Movement of the tumblers 38 is limited by a shoulder 39 on the housing side.
The additional tumblers 38 are urged inwardly by tumbler-pins 40 on the housing
side which are in turn accommodated in closed radial bores 41 in the cylinder
housing 1'. The tumbler-pins 40 are pot-shaped and each contains a compression
spring 42 in its interior.
If the correct key 35 is inserted into the key-channel 10', the sphere
19 pass through the undulating section of the key-channel formed by the pins 36,
37, urging the additional tumblers 38 outwardly against the action of their
springs. When the key is fully inserted therefore, the junction between the
additional tumblers 38 and the tumbler pins 40 lies on the core-rotation cylin-
drical surface. Since the remaining tumblers 8 are now also indexed, the
cylinder core may be turned by key 35. Furthermore, in the fully inserted posi-
tion, the spheres 19 lie upon the end-faces of pins 36.
The variants illustrated in Figures 8 to 10 relate to a cylinder lock
in which a key 43 indexes the main tumbler pins 8 by means of recesses 44 ar-
ranged in its wide sides. Pins 45, 46, accommodated stationarily in the cylinder
2Q core, are arranged parallel with the tumbler pins 8 but with the gaps in effect
relationship thereto. Inner ends 45' of the pins 45 also project into the key-
channel 46, in such a manner that the distance between the opposing lateral wall
47 of the channel and inner end 45' corresponds to the diameter of the sphere 19,
carried in the shank of key 45. In the embodiment illustrated, the sphere 19 is
accommodated in a bearing bore 49 extending, in the key shank, between two oppos-
ing profiled longitudinal grooves 50 therein. Thus the latter may be used as a
reversing key. The sphere 19 is thus displaceable and can therefore project
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llS3~03
beyond the ~ase of either proflled..longitudinal groove 50.
Located opposite the pins 45, and between them, is pin 46, the free
end 4~' of which enters tne key-channel lO" to the extent that the distance
between the inner end 46' and the opposing lateral wall 51 of the channel cor-
responds to the diameter of the sphere 19, as shown in Figure 10 in dotted lines.
The pin 46 is in the form of a mushroom-pin, the head 46" thereof being accommo-
dated ln a counterbore 52 in the cylinder core and resting upon the inner wal~ of
cylinder core bore 2' in housing 1". Counter~ore 52 is of a length such that
the inner end 46' projects beyond the lateral wall 47 of the channel by a spe-
lQ cific amount.
Tumbler 53, located after the mushroom-pin 46 in the direction of in-
sertion, is also in the form of a mushroom-pin. The head 53' thereof is located
in a counterbore 54 in the cylinder core and is acted upon by a non-rotatable
housing pin 55. The latter is equipped with a radially projecting tongue 56
guided in a groove 57 extending away from the bore in the housing. A spring-
loaded housing pin 58 bears uponthetongue 56. This urges the housing pin 55
into the counterbore 54 and displaces the tumbler 54 in such a manner that it
projects into the key-channel 10".
Now if, as shown in Figure 9, the key 43 is inserted into the key-
2Q channel 10", the sphere 19 travels through the undulating section of the channel
formed by the pins 45, 46.
In the fully inserted position, the sphere 19 then displaces the tum-
;~ bler 53 to an extent such that the junction between it and the housing-pin 55
lies upon core-rotation surface,.D.
In the embodiment illustrated in Pigure 11, the same tumbler 53 is used,
and is preceded, on the same side of the key-channel 10", by a mushroom-pin 46.
The channel-wall 51' facing the inner end 46' of pin 46 is equipped with a recess
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~153~C)3
59 the distance between the bottom of the recess 59 and the end 46' of mushroom-
pin 46 corresponding to the diameter of the sphere 19. Thus, the recess 59 in
conjunction with the pin 46, forms an undulating path adapted to the diameter of
rolling element 19.
In the variants of key 60 illustrated in Figures 12 and 13, the wide
sides of the key also index the main tumbler pins. In contrast to the design of
key 43 described hereinbefore, a bearing bore 61 is located in a bush 62 which is
lightly peened over at both ends and is pressed into an opening in the central
area of the key-shank. Profiled longitudinal grooves 63 extend on each side of
the bush, in such a manner that the ends 62' of the bush lie flush with the bases
of these grooves. As shown in Figure 12, this makes it possible to displace the
sphere lS from the terminal position shown in full lines to the terminal posi-
tion indicated in dotted lines. This is again achieved by the pins or projec-
tions in the key-channel projecting into profiled longitudinal grooves 63.
It may be seen from Figure 13 that rolling element 19 is offset in
relation to the line of consecuti~e recesses 44.
Similar parts in the cylinder-lock illustrated in Figures 14 and 15
bear the same reference numerals as the design in Figures 8 to 10. Facing the
tumbler 53, which is also mushroom-shaped, and in alignment therewith, in a
stepped bore 64, is a control pin 66 acted upon by a compression spring 65 and
forming the projecting zone. The other end of spring 65 bears upon a plug 67
which closes off the bore 64 and conforms externally to the core-rotation sur-
face F. Control pin 66 is provided with a collar which faces towards spring
65 and bears upon a step 69 in bore 64. Thus the free end 66' of the control
pin 66 can project into the key channel lQ" by only a specific amount.
As shown in dotted lines in Figures 14 and 15, the height of the key
channel 10", in the area of the linear passage for the sphere 19, corresponds to
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~ ~.539~3
the diameter of the latter. In contrast to control-pin 66, the mushroom-tumbler
53 is guided in such a manner that the mushroom-head 53' prevents the tumbler 53
from entering key-channel 10".
Now if the key 43 is inserted in the key-channel 10" in this cylinder-
lock, the sphere 19 entering the groove 50 in the key, passes through the
linear passage which matches it in size, and acts upon the control pin 66 just
before it reaches the fully inserted position, and the pin 66 shifts against the
force of the compression spring 65. Tn the fully inserted position, the
control-pin 66 is then aligned with the sphere 19 and the bearing bore 49
allowing the pin to press the sphere 19 towards the tumbler 53. Since the
compression spring 70 acting upon housing-pin 55 is weaker than the spring
acting upon control-pin 66, the tumbler 53 is displaced by the sphere 19 and
the control-pin 66 in such a manner that the junction between the tumbler 53
and the housing-pin 55 lies upon the core-rotation surface F. Thus the pin 66
also serves to close off bearing bore 49, which prevents unauthorized manipula-
tion of tumbler 53 from the outside.
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