Note: Descriptions are shown in the official language in which they were submitted.
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3410-26
The invention relates to a lock-key system particularly in a hier-
archal lock system, and more particularly to a configuration arrangement for
a key.
Lock and key systems are well known wherein the variation or system
profile used to differentiate between master keys and subordinate keys is
allocated to the facing region of the key, that is, to the region which carries
the classification notches, whereas the section adjacent to the spine of the
key is provided with an invariable basic or guide profile. The disadvantage
of these allocations of variation and invariable base profiles results from
the fact that the key channel must be kept limited to a straight line and must
have a minimum width precisely in the region of the tumblers, this opening up
possibilities for the introduction and actuation of picking or sensing tools.
The present invention avoids the disadvantage described above by
reversing the placement of the variation profile and the invariable basic
profile. Thus, the invariable basic profile is allocated to the region of the
key facing carrying the classification notches and thus providing this area
with at least two profiled formations, that is a paracentric profile formation,
which cross the centerline of the key. Also, the variation or system profile
is moved into the section adjacent to the key spine.
The advantage achieved by such a rearrangement is that the key
channel thus comprises a dentate design in the region of the basic profile
section which largely prohibits access by picking tools, the consequence thereof
being that security against picking is considerably enhanced.
Thus, in accordance with one broad aspect of the invention, there is
provided a lock-key system, particularly for hierarchal lock systems, wherein
the keys are provided with an invariable basic profile and with a variation
Pat/Pt/1386 S
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profile comprising the improvement of: said invariable basic profile being
contained in a region of a key facing carrying a plurality of classification
notches and is provided with at least two profile formations which cross the
centerline of the key; and said variation profile being positioned in a
section adjacent to the key spine, said variation profile includes at least one
safety rib profile projecting beyond a lateral face of the key; and said basic
profile and variation profile are comprised of profile incisions which have a
rectangular cross-section.
In accordance with another broad aspect of the invention there is
provided, in a key for use in a hierarchal lock system with an elongated body
having a spine portion and a facing portion carrying a plurality of classifi-
cation notches, an improvement comprising: an invariable basic profile formed
in said facing portion and a system profile comprising longitudinal incisions
formed near said spine portion wherein higher order keys in the hierarchy have
more incisions than do lower order keys.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is an end view of a prior art key.
Figure 2 is an end view of a master key embodying the principles of
the present invention.
Figure 3 is an end view of a key subordinate to the key shown in
Figure 2.
Figure 4 is an end view of an additional key subordinate to the key
shown in Figure 2 which is supraordinate to the key shown in Figure 3.
Figure 1 shows an end view of a prior art key 1 in which a basic
profile section 2 is allocated to the section adjacent to a key spine 3 and a
variation profile 4 is allocated to the section adjacent to a key facing 5
provided with the classification notches. Possible profile variations are
indicated in Figure 1 by dotted lines and it is evident that the key channel
must at least comprise an opening 6 limited by a straight line in its basic
shape in the region of the variation profile and having a minimum width, the
straight line lying generally along a centerline 9 of the key 1.
A key 11 embodying the principles of the present invention is shown
in Figures 2-4 which is quite distinct from the prior art key 1 in that an
invariable basic profile 7 is now positioned in a key facing section 5' contain-
ing the classification notches, and a system or variation profile 8 is in
a section of the key 11 close to a spine 3~ of the key. The variation profile
area 8 can extend from the spine 3' to the middle part of the key 11.
Figures 3 and 4 each show a key 12, 13 having many possible forma-
tions of the variation profile. Specifically a plurality of protrusions or
elevations 14 are provided along the part of the keys 12, 13 just below the
spine 3'. The key 13 of Figure 4 has some of the same protrusions 14 as the
key 12 of Figure 3, but not all of them. Key 13 may also be viewed as having
more incisions than key 12, that is, a lack of protrusions being equated with
an increase in incisions. Thus, key 12 is subordinate to key 13 in a hier-
archal lock system in that key 13 will fit into all locks which can receive key
12 and then some. There are no locks which will receive key 12 but not key 13.
Key 11 is a master key over both keys 12 and 13 since all of the protrusions
14 have been removed. Thus, key 11 is a higher order key, the hierarachy and
can fit into every lock which can receive key 13 or key 12 as well as others.
Common to each of the keys, however, is that they carry a basic
profile 7 in the lower section, namely that of the key facing 5'. The basic
profile 7, as shown in the illustrative embodiments, consists of a paracentric
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which crosses the center line 9 at 3 points indicated at points 15, 16 and
17. A key channel 10 in the lock which receives the basic profile 7 thus has
a dentate course which largely prevents work with lock-picking tools.
An additional feature of the key which enhances the security against
unauthorized opening of the lock is that the key contains at least one safety
rib profile 18, that is, a profile that projects beyond the case or flat side
of the key so that reworking of the key can only occur by means of applying
additional material. Four safety ribs 14 are shown in the embodiments of
Figures 2 through 4.
It is quite advantageous to fabricate the profile incisions and ele-
vations 14 with a rectangular cross-section as is shown in the figures. This
enables an economic manufacture of the keys and, as a consequence thereof, a
multitude of variations can be undertaken because a very slight width of the
profile incisions can be produced, for example, by means of milling disks.
Applicant has found that incisions which have a width of 0.6 millimeters can
be incorporated in keys with surprising success. Thus, a large number of
incisions can be made along the height of the key as is shown in the figures
resulting in a large available variation in a multiple lock system.
As is apparent from the foregoing specification, the invention is sus-
ceptible of being embodied with various alterations and modifications which may
differ particularly from those that have been described in the preceding
specification and description. It should be understood that I wish to embody
within the scope of the patent warranted hereon all such modifications as
reasonably and properly come within the scope of my contribution to the art.
