Note: Descriptions are shown in the official language in which they were submitted.
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GK-ISL-645
ROTARY LOCKING CYLINDER FOR A SAF}STY LOCK
BACRGROUND OF THE INVENTION
a) Field of the Invention
The invention is directed to a rotary locking cylinder
and, in particular, to a rotary locking cylinder for a safety lock
in which spring-loaded pin tumblers are supported in bore holes
extending radially relative to a rotor and a cylinder housing and
can be brought into line by inserting a key into a key groove to
enable the rotation of the rotor.
b) Deccriptio~ of the Related Art
A rotary locking cylinder of this type is known, for
example, from EP-B-0 238 442. In break-in attempts, even high-
priced rotary locking cylinders of this kind are subject to a wide
variety of known and new methods of opening. Some of these methods
are non-destructive and incapable of detection. The rotary locking
cylinder according to the patent mentioned above foils such
methods, e.g. the vibration method, by way of a special a
construction of the tumblers. However, there are also methods of
unauthorized opening in which the rotary locking cylinder is
destroyed by the use of crude force. When attempting to open the
lock in this way, for example, rotation of the rotor is forced by
inserting a tool into the key groove so that the tumbler pins are
sheared off. This forced method of entry is difficult to combat by
modifying the rotary locking cylinder, since such changes are
restricted by preestablished dimensions. Yinally, such a rotary
locking cylinder should be simple and inexpensive to manufacture
and should operate reliably. A rotary locking cylinder which at
least substantially impedes a number of methods of unauthorized
opening at the same time would be particularly desirable.
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L~M~r OF THE PRESENT INVENTION
The invention therefore has the primary object of
providing a rotary locking cylinder of the type mentioned above
which offers better protection against at~empts at unauthorized
opening but is not substantially more expensive to produce. This
object is met by the invention wherein the improvement comprises a
blocking insert which is suppor~ed in the housing and engages in
the key groove and is displaced outward against a repelling spring
force when the key i5 inserted in order to free the rotor for
rotation.
In the rotary locking cylinder according to the invention
the above-mentioned break-in attempts are substantially impeded.
Forced turning of the rotor is impeded by increasing the shearing
cross section, i.e. the tailor-made tool employed for this purpose
must be inserted into the key groove along the entire length of the
latter. The tool which is inserted into the key groove strikes
against the core pins due to the spring pressure of the blocking
insert. These core pins are accordingly moved outward radially,
which results in a positive blocking by means of the core pins. It
is almost impossible to force a rotor which is blocked in this way.
In order to use the lock-picking method or vibration
method, the blocking insert would have to be held against the
spring pressure at the locking level along the entire length of the
key groove while attempting to open the lock. Accordingly,
additional manipulation is required so that the opening method is
made more difficult and the period of time required to successfully
open the lock is increased.
As will be seen, entirely different types of opening
methods are substantially impeded by the rotary locking cylinder
according to the invention.
The rotary locking cylinder can be operated in a
conventional manner with its accompanying key. When the key is
inserted into the key groove, the blocking insert is automatically
moved outward into an inactive position.
The rotary locking cylinder according to the invention
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can be manufactured in a partlcularly simple manner according to a
further development when the insert is inserted in a recess of the
housing which is open towar~ the rear. In this case, the insert
can be pushed into a longitudinal recess of the housing in the
manner of a slide or bolt. The ir~sertion of the blocking insert
may be effected during assembly of the rotary locking cylinder much
as the insertion of the housing pins. The insertion of the
blocking insert can accordingly be integrated very simply in a
known production process. This is an important feature in series-
manufactured products.
The locking security is considerably increased in a
further development of the invention in that the blocking insert
has a plurality of parts arranged one after the other which must be
displaced outward individually in order to release the rotor.
Accordingly, a plurality of parts of the blocking insert must be
brought into the inactive position simultaneously when unauthorized
opening is attempted.
The locking security is further increased in that the
blocking insert is held in the blocking position by means of at
least two spring elements which are arranged at a distance from one
another. Such a blocking insert is also still effective when
pressed outward at only one end. In this case, the blocking insert
is only inclined and the end which is not acted upon continues to
lock the rotor.
The rotary locking cylinder according to the invention
can also be a double locking cylinder having two individual parts
joined by a connecting web. In this case, the blocking inserts are
installed before connecting the individual cylinders. Accordingly,
the blocking inserts can also be pushed in from the rear in this
instance. Further advantageous features are contained in the
following claims and the description and drawing.
BRIEF DEBCRIPTION OF T~E DRAWINGS
In the drawings:
Fig. 1 shows a cross section through a rotary locking
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cylinder according to th~ invention; and
Figs. 2a to 2c show longitudinal sections through the
rotary locking cylinder with partial views of a key shaft.
D~SCRIPTION OF THE PREFERRED EMBODIMENT~
The rotary locking cylinder has a housing with a
' continuous bore hole 5 in which a rotor 9 is inserted. Spring-
loaded tumblers with springs 4, core pins 8 and housing pins 3 are
inserted into radial bore holes in the rotor 9 and into inserts 2
of the housing 1 in a known manner. A flat key or turn key 14 is
inserted into an open key groove 10 to enable rotation. If the
rotary locking cylinder has two individual cylinders, these
cylinders are connected with one another by a web 7 inserted into
the cylinder pocket 6. The rotary locking cylinder according to
the invention can be a single rotary locking cylinder or double
rotary locking cylinder.
A recess 11 extending in the longitudinal direction of
the rotary locking cylinder is worked into the housing 1 in the
lower region of the bore hole 5. As will be seen from Fig. 2a,
this recess is open at the rear, i.e. with reference to the figure,
while it is closed in the front. A blocking insert 12 having two
parts 12a and 12b which are T-shaped in cross section and made of
brass, for example, is inserted into this groove-shaped recess 11.
The parts 12a and 12b have two pocket bore holes 12c in the
underside, spiral springs 13 being inserted into the latter. The
spiral springs 13 supported at the housing 1 hold parts 12a and 12b
in the position shown in Figures 1 and 2a. Since, as can be seen
in the drawing, parts 12a and 12b project into the key groove 10
which is open at the bottom, the blocking insert 12 connects the
rotor with the housing 1 in the position shown in the drawing.
Accordingly, the rotor could not be turned even when the tumblers
are brought into line. Consequently, a lock with this rotary
locking cylinder could not be opened by a break-in method in which
the tumblers are simply brought into line.
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The rotary locking cylinder can be operated i~ a
conventional manner by inserting the correct turning key 14 into
the key groove 10 as is shown in Figures 2b and 2c. When the key
14 is inserted into the key groove 10 from the front, as is shown
in Fig. 2, part 12a first and then part 12b are moved downward into
the recess 11 against the repelling force of the springs 13. In
the position shown in Fig. 2c in which the key 14 is completely
inserted into the key groove 10, parts 12a and 12b no longer
project beyond the recess 11 at the top and also no longer engage
in the key groove 1o. Since the tumblers are simultaneously
brought into line by the key 14, the rotor 9 is released.
Parts 12a and 12b have a T-shaped cross section, as is
shown in Fig. 1, along their entire length. Accordingly, they have
an upper projection 12c which is only slightly narrower than the
key groove 10. A lower region 12e is wider than the key groove 10
and only slightly narrower than the recess 11. The wider region
12e accordingly forms a stop which prevents parts 12a and 12b from
being pressed completely into the key groove 10 by the springs 13.
When the key 14 is removed, parts 12a and 12b immediately move
automatically into the position shown in Fig. 2a.
While the foregoing description and drawings represent
the preferred embodiments of the present invention, it will be
obvious to those skilled in the art that various changes and
modifications may be made therein without departing from the true
spirit and scope of the present invention.
