Locking device with a cylinder lock and a flat key

On a cylinder lock (1) tumblers (10) are disposed which extend parallel to the broad side (8, 9) of the lock channel (6). The ends of these tumblers (10) block between the rotor (3) and the stator (4). On the rear side (17), facing away from the key channel (6), of the tumblers (10) are disposed additional codings. These codings cooperate with additional two-part blocking elements (20). These blocking elements (20) are displaceable at right angles to the lock axis and block in addition in the region of the shear line (32) between rotor (3) and stator (4). Therewith additional blocking combinations are possible and the security of the lock against unauthorized opening is increased.

FIELD AND BACKGROUND OF THE INVENTION 
The invention relates to a locking device with a cylinder lock and a flat 
key wherein the cylinder lock comprises a rotor rotatable in a stator with 
a key channel, and guides disposed approximately at right angles to the 
longitudinal axis of the rotor and parallel to the broad sides of the key 
channel which {guides} comprise tumblers provided with carriers projecting 
into the key channel, and the flat key comprises on the broad sides guide 
tracks which when the key is introduced into the key channel engage the 
carriers of the tumblers and at least in one portion of the tumblers on 
the rear side facing away from the key channel a hollow is disposed which 
cooperates with an additional blocking element. 
Such a locking device with a cylinder lock and a flat key is known from 
U.S. Pat. No. 3,035,433. In the rotor of a cylinder lock is disposed a key 
channel which extends in the direction of the lock, respectively rotor, 
axis. This key channel serves for receiving a flat key. On the broad sides 
of the flat key are disposed guide tracks for positioning tumblers in the 
cylinder lock. These tumblers are supported in the lock in guides which 
are at right angles to the lock axis and extend parallel to the broad 
sides of the key channel. The tumblers comprise carriers which project 
into the key channel, respectively protrude into it and when the key is 
introduced into the key channel engage the guide tracks on the key. When 
the key is introduced completely into the key channel, and provided the 
guide tracks have the correct positioning planes for the carriers, the 
tumblers are completely in the rotor of the lock, and the rotor can be 
rotated in the stator. The lock comprises also an additional blocking 
element. This is disposed between the rear side of the tumblers and the 
stator and comprises a blocking bar which extends parallel to the lock 
axis and over all tumblers. This blocking bar is pressed by springs toward 
the outside into a groove with ramp surfaces in the stator. It is 
displaced from the groove in the stator by rotating the rotor and pushed 
against the rear side of the tumblers. In order for this displacement to 
be possible, into the rear side, facing away from the key channel, of the 
tumblers one groove each is worked which extends parallel to the blocking 
bar. The depth of this groove corresponds at least to the displacement 
path of the blocking bar during the rotation of the rotor. Otherwise, the 
rotor cannot be rotated and the lock cannot be opened. 
Blocking bars of the known type form an additional element which secures 
the rotor in the stator against rotational movements. However, they do not 
form an additional security against unauthorized manipulations, for the 
example the so-called picking of the lock since the tumblers can be 
brought independently of the blocking bars into the opening positions. 
During the positioning process of the tumblers no cooperation exists 
between tumblers and blocking bar. Cooperation is only initiated if first 
the rotor can be rotated in the stator, i.e. if the tumblers are correctly 
positioned. As soon as the tumblers are in the correct opening position, 
however, the displacement path for the blocking bars is also released, 
since the groove on the rear side of the tumbler is also in the correct 
position. 
SUMMARY OF THE INVENTION 
The invention is based on the task of improving a locking device of the 
known type to the effect that the correct opening position of the tumblers 
is additionally encoded, and the additional coding is to be possible for 
each tumbler individually and for each tumbler a separate additional 
blocking element is to be available, and in the same lock tumblers without 
this additional coding or blocking can be also be disposed. Furthermore, 
the additional blocking element with the key pulled off is to maintain the 
particular tumbler in the blocked position and itself bring about an 
additional blocking between rotor and stator as well as permit the 
utilization of the peripheral dimensions of the tumblers. 
This task is solved through the teaching provided in the invention. 
Advantageous further developments of the invention are evident based on 
the characteristics of the dependent patent claims. 
The disposition of an additional two-part blocking element for at least a 
portion of the tumblers, and for each of the particular tumblers, yields 
the advantage that to each additional blocking element can be assigned a 
separate precisely definable opening position. Through the two-part 
implementation it is also possible to assign to each additional blocking 
element a shearing face which is implemented between the two blocking 
element parts and cooperates with the shearing face between rotor and 
stator. Each of the additional blocking elements is therein always in 
contact with the rear side of the tumblers on which several additional 
codings for blocking and opening positions of the additional blocking 
elements are implemented. This implementation of several different codings 
on the rear side of the tumblers has the advantage that the opening 
position of the lock is determined by two codings, namely, on the one 
hand, that on the key and, on the other hand, that on the rear side of the 
tumblers. A further advantage comprises that tumblers can also be used 
which engage the stator only in the peripheral region, i.e. in the 
outermost positions, in the remaining displacement region of the tumblers, 
however, would permit a rotation of the rotor. But in this displacement 
region the additional blocking element prevents the rotation of the rotor 
as long as there is no cooperation between the correct coding on the rear 
side of the tumbler with the additional blocking element. 
Through the implementation of the codings on the positioning face on the 
rear side of the tumblers in the form of hollows or peaks, or a 
combination of hollows and peaks, a large number of blocking combinations 
can be generated. The peaks or the peripheral regions between two adjacent 
hollows opposite the blocking element part form tipping edges which permit 
the positioning only with the forced guidance of the tumbler. When 
attempting to displace the tumblers freely into an opening position, the 
end of the blocking elements in contact on the tumbler always presses the 
tumbler into a blocking position. Thereby the blocking elements is also 
not located in the opening position. This process is brought about through 
the tipping edges and the spring loading of the blocking elements acting 
in the direction of the tumblers. In further combination with planar faces 
which extend approximately parallel to the longitudinal axes of the 
tumblers, further coding advantages result. 
By disposing a recess in the rear side of the tumbler and inserting a 
plate, advantageous two-part tumblers are obtained. The plate therein 
encompasses the positioning face for the additional blocking element with 
this positioning face being provided with the desired codings. Identically 
formed tumblers with identical dimensions can be equipped with different 
plates whereby the desired additional combination variants of blockings 
result. The plates are in known manner connected with the tumblers through 
a press fit, by adhesion or joining processes of similar type. The plates 
can also additionally be made uniform thereby that into the positioning 
face a row of bores with identical diameter is worked. These bores 
comprise in the exit region countersinks with identical or different 
dimensions; and into the bores are inserted, as necessary, additional pins 
with head pieces. The head pieces form therein elevations and/or planar 
faces. 
These multiply new combinations capabilities of the tumblers according to 
the invention and additional blocking elements with the two independent 
coding capabilities a considerable increase of the possible blocking 
combinations result. Unauthorized interventions into the lock, 
respectively the opening of the lock without the correct key, are made 
considerably more difficult if not impossible. The forced intervention of 
the additional blocking elements into the codings on the rear side of the 
tumblers fixes these in the position into which they had been moved when 
the key was pulled from the lock. The lock can thereby be set in in any 
installation position without the danger that the tumblers do not assume 
the desired positions within the guides. They can also not be displaced 
from the blocking positions by vibrations. Moreover, it is also possible 
to combine only a portion of the tumblers available in a lock with 
additional blocking elements, which, nevertheless leads to an increase of 
the lock security and operational security.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
The locking device depicted in FIG. 1 comprises a cylinder lock 1 and a 
flat key 2, in the example shown a flat turning key. The cylinder lock 1 
is shown in simplified form and comprises a rotor 3 which is rotatable in 
a stator 4 and a sleeve 5 which encompasses the entire cylinder lock 1 as 
a jacket. Into the rotor 3 is worked a key channel 6 with a rectangular 
cross section. Into this key channel 6 can be introduced the key bit 19 of 
the key 2. Into the broad sides 13, 14 of the flat turning key 2 are 
milled guide tracks 15, 16 in the form of grooves, which serve for 
positioning the locking element in the cylinder lock 1. Since the key 2 is 
a turning key, on the not visible broad side 14 the groove 15 is disposed 
at the bottom and the groove 16 at the top. With respect to the center 
axis 33 of the key 2, thus identically formed grooves 15, respectively 16, 
are diagonally opposing each other on the two broad sides 13, 14. In the 
example depicted, on each broad side 8, 9 of the key channel 6 in the 
rotor 3 five tumblers 10 are disposed such that ten locking elements 
result. These tumblers 10 are supported in guides 11 of the rotor 3 and 
are displaceable transversely to the longitudinal axis 7 of lock 1. At the 
rear end 18 of the rotor 3 are available elements which are not shown but 
are known elements which cooperate with elements, also not shown, for 
example on a door latching. 
In FIG. 2 the disposition of the tumblers 10 in the cylinder lock 1 is 
shown. The tumblers 10 are placed in guides 11 in rotor 3. In that 
position of the rotor 3 in which the key 2 can be pulled out of the key 
channel 6, the guides 11 cooperate with bores 34, 35 in stator 4, and one 
end of the tumblers 10 engages these bores 34, respectively 35. In the 
position, shown in FIG. 2 in the left lock half, of the tumbler 10 in 
rotor 3 and stator 4, the lock 1 is blocked, i.e. the rotor 3 cannot be 
rotated relative to stator 4. The tumbler 10 is in this position when the 
key 2 is pulled off, which is the reason why no key is depicted in the 
left portion of the key channel 6. For actuating the tumblers 10 carriers 
12 are disposed on these, which project into the key channel 6. If the key 
bit 19 depicted in FIG. 1 is inserted into the key channel 6, the carriers 
12 engage the groove 16 and a corresponding groove 15 on the rear side, 
and the tumblers 10 are moved corresponding to the contour of grooves 15, 
16. If the grooves 15, 16 are correctly encoded, then with the key 2 
completely introduced all ten tumblers 10 are in the opening position, 
i.e. completely within within rotor 3. This position of the tumbler 10 is 
depicted in the right half of FIG. 2, which also shows key 2. The rotor 3 
could thus be rotated in stator 4 if only the tumblers 10 were available 
as blocking elements. 
In the embodiment according to the invention, between the tumblers 10 and 
the stator 4 are disposed additional blocking elements 20. These blocking 
elements 20 are in two parts and comprise a first part 21, which is 
supported in a bore 24 in the stator 4, and a second part 22, which is 
supported in a bore 25 in the rotor 3. In the blocking position shown of 
lock 1, respectively in the position of rotor 3 in stator 4 in which the 
key 2 can be pulled off, the axes 26 and 27 of the two bores 24 and 25 
coincide. In this position the two bores 24 and 25 form a common guide 
bore in which the blocking element parts 21 and 22 can be moved back and 
forth between stator 4 and rotor 3. The first blocking element part 21 is 
implemented in the form of a pot and is pushed by a compression spring 36 
in the direction of the tumbler 10. The second blocking element part 22 
comprises a shoulder 37 which cooperates with the offset of the step bore 
25. Between the two blocking element parts 21 and 22 a dividing face 23 is 
formed along which the two parts 21 and 22 can be moved relative to one 
another. The offset end 28 of the second blocking element part 22 rests in 
contact on the rear side 17 of the tumblers 10. As rear side 17 of the 
tumblers 10 that side of the tumblers 10 is denoted which faces away from 
the key channel 6. This rear side 17 is equipped with a positioning face 
29 into which the codings are worked in the form of hollows 30, 31. The 
end 28 is formed corresponding to the slope forms of the hollows 30, 31 
and in the example depicted tapers into a peak. If the tumblers 10 are 
displaced in the direction of their longitudinal axes 38, respectively 
parallel to the broad sides 8, 9 of the lock channel 6, the end 28 of the 
second blocking element part 22 in each instance snaps into the hollows 
30, 31. The outermost hollow 31 in the positioning face 29 of the tumbler 
10 is therein implemented to be especially deep. It maintains the tumbler 
10 after the key 2 is pulled from lock 1 in the blocking position in which 
one end of the tumbler 10 engages the bore 34 of stator 4. In addition the 
blocking element 20 also blocks in bore 24 since the first blocking 
element part 21 is displaced beyond the shear line 32 between rotor 4 and 
stator 3. The tumbler 10 shown in FIG. 2 in the right half is depicted in 
the opening position, i.e. it does not engage with either of the two ends 
the bore 35 on stator 4. The tumbler 10 is held in this position by key 2 
thereby that the carrier 12 is held and positioned by the guide track 16. 
The end 28 of the second blocking element part 22 rests therein on an edge 
39 between two hollows 30 serving as tipping edge. The dividing face 23 
between the two blocking element parts 21 and 22 is therein disposed on 
the shear line 32 between rotor 3 and stator 4. If all blocking elements 
20 of lock 1 are in this position and no tumbler 10 engages a bore 34, 35 
of the stator 4, the rotor 3 can be rotated. Attempts to position and hold 
the tumblers 10 with foreign means and without the correct key 2 in this 
opening position, fail since the end 28 of the blocking element part 22 
snaps immediately into one of the two hollows on both sides of the tipping 
edge 39 and displaces the tumblers 10 into a blocking position. In the 
blocking position one end of tumblers 10 again engages the bore 35 on 
stator 4. In addition, the two blocking element parts 21, 22 are displaced 
against the tumbler 10 whereby the dividing face 23 no longer coincides 
with the shear line 32, and the first blocking element 21 blocks the rotor 
3. 
The tumblers 10 in FIG. 2 are implemented in two parts. On the rear side 17 
is disposed a recess 40 into which a plate 41 is placed. The connection 
between plate 41 and tumbler 10 is brought about through a press fit, an 
adhesion connection or another known suitable connecting technique. In the 
example according to FIG. 2 the plate 41 is integrally connected with the 
carrier 12 and pressed as a whole into the corresponding recess 40 of the 
tumblers 10. This embodiment has the advantage that the tumblers 10 can be 
prefabricated in the desired standard dimensions. The implementation of 
the desired coding on the rear side 17 of the tumbler 10 takes place 
through the assembly with a correspondingly implemented plate 41. Therein 
it is also simultaneously possible to vary the diameter of the carrier 12. 
A further advantage comprises that the tumblers 10 themselves, as is 
known, can be manufactured for example of nonferrous heavy metal, for the 
plate 41 with carrier 12, however, a hard material or hardened steel can 
be used. This increases significantly the abrasion resistance and service 
life of the lock 1. 
FIG. 3 shows a two-part tumbler 10 in enlarged perspective view. In 
actuality the tumblers 10 are only a few millimeters long. The plate 41 
which is set into the recess 40, comprises on the positioning face 29 
hollows 30 and 31 and peaks 42, with the latter projecting beyond the face 
29. Between the hollows 30, 31 and/or peaks 42 planar faces 43, 44 are 
also present which extend approximately parallel to the longitudinal axis 
38 or the tumbler 10. The correct opening position for the additional 
blocking element 20 can be predetermined or coded on a peak 42, in a 
hollow 30, 31, on a planar face 43, 44, or in an intermediate position, 
for example on an oblique slope. This multiplicity of additional coding 
feasibilities for the additional blocking element 20 increase 
significantly the blocking variants for a correspondingly implemented lock 
1. It is also apparent that the unauthorized opening of the lock, for 
example by picking, is made virtually impossible since the correct 
position of the additional blocking elements 20 and the correct position 
of the tumblers 10 with respect to one another is superimposed and the 
opening combinations are not detectable. The additional blocking elements 
20 in the blocking position block the rotor 3 effectively and free of play 
against rotary movements in the stator 4. This permits, if necessary, also 
the use of tumblers 10 which in the blocking position engage the bores 34, 
35 in the stator 4 only minimally, i.e. have peripheral dimensions. Since 
the blocking elements 20 block effectively, the ends of the tumblers 10 
with peripheral dimensions can also not be deformed or damaged even when 
force is exerted onto the rotor 3. 
In the cross section depicted in FIG. 4 through a lock 1 tumblers 10' and 
10" are shown which are equipped with a further embodiment of the plate 
41. In it, into the positioning face 29 on plate 41 a row of bores 45 are 
worked which form the coding for the end 28 of the second blocking element 
part 22. In addition, the bores 45 are provided with countersinks 46. On 
the right side of FIG. 4 an additional modification of this plate 41 with 
bores 45 is depicted wherein at least into a portion of the bores 45 pins 
47 with head pieces 48 are set. These head pieces form peaks with tipping 
edges, but can also comprise end faces. This embodiment permits the 
adaptation or change of codings on the rear side 17 of the tumblers 10', 
respectively 10" in a particularly simple manner since the desired 
tumblers can be assembled from prefabricated single parts and as needed. 
In the left half of FIG. 4 is also evident that the carrier 12 can be set 
into the tumblers 10' as a separate part. For the remainder, the lock 1 
depicted in FIG. 4 with key 2 has all of the characteristics as were 
already described in connection with FIG. 2. 
In the embodiment of the lock according to FIG. 2 as well as also according 
to FIG. 4, in addition to the tumblers 10, 10' or 10" shown, tumblers with 
positioning faces 29, respectively codings, implemented differently, for 
the additional blocking element 20 can also be used. In the lock according 
to FIG. 4, for example, one or several tumblers according to FIG. 3 can be 
used. In each case, the advantages result that the opening positions of 
the tumblers 10, 10' or 10" are additionally encoded, and the additional 
coding for each tumbler 10, 10' or 10" takes place individually and can be 
changed individually. Each additionally coded tumbler 10, 10' or 10" 
comprises a separate additional blocking element 20. This blocking element 
20 maintains the tumbler 10, 10' or 10" when the key 2 is pulled off in 
the blocking position and blocks the rotor 3, in turn, itself additionally 
against rotary movements in the stator. The installation of a lock 1 
implemented according to the invention is possible in any position since 
the tumblers 10, 10' or 10" are positioned into the terminal positions and 
held through the blocking elements 20 and cannot assume independently any 
undesired positions along the guides 11 in rotor 3 or stator 4. The 
additional blocking elements 20 can block positively or negatively between 
rotor 3 and stator 4. If the dividing face 23 is located between the first 
part 21 and the second part 22 of the blocking element 20 in the region of 
stator 4, and thus outside of the circle of the shear line 32 the blocking 
is referred to as positive. The second part 22 of the blocking element 20 
projects into stator 4. In the case of negative blocking, the first part 
21 projects into rotor 3, and the dividing face 23 is disposed within the 
circle of the shear line 32 between rotor 3 and stator 4. 
Tumbler 10" in the right half of FIG. 4 illustrates a further advantages of 
the invention. In locking systems with many different locks and keys, 
tumblers 10" must to some extent be used whose end portion 49 is too short 
in order to be able to engage stator 4 in the end position. With the key 
pulled off, such tumblers 10" cannot assume any blocking function. By 
means of the two-part blocking element 20 this blocking function, however, 
is again obtained. When pulling off the key 2 from lock 1 the tumbler 10" 
is guided last completely downwardly, and the second blocking element part 
22 snaps into the outermost hollow 50. Thereby the first blocking element 
part 21 is displaced beyond the shear line 32 toward the inside, and the 
rotor 3 is blocked against displacement in stator 4. Thus a considerable 
improvement of the lock security is attained. A further advantage 
comprises that in closing systems with a relatively large number of 
differently coded locks individual locks can be equipped selectively with 
additional codings concerning the blocking elements 20. This permits also 
when using tumbler 10" with short end portions 49 the additional expansion 
of the blocking combinations and thus an improvement of the security.