Note: Descriptions are shown in the official language in which they were submitted.
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SPECIFICATION
This invention relates to locking mechanisms and in
particular, the~keys used to operate locking cores housed
within locking mechanisms.
It is common for locking systems to provide separate
operating keys and control keys for use with rotatable locking
cores. An operating key is employed to lock and unlock a
corresponding core when the core is housed in the locking
mechanism. For esample, if a locking mechanism is installed to
secure a desk drawer against openinq when locked, the operating
key may be used to lock and unlock the core, thereby in turn,
permitting the secure closure and opening, respectively, of the
drawer.
A control key may be used for additional functions
including, acting as a master key to operate a number of
different locking cores or as a key to permit removal of a
locking core from its corresponding housing. Typically, a
control key i~ provided with a bitted portion which is capable
of activating one or more control tumblers in a locking core.
When such control tumblers are activated, usually upon
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insertion and rotation of the control key to a predetermined
position, removal of the locking core from the housing may be
achieved. Alternately, where a control key functions as a
master key, the bitted portion of the control key is adapted to
activate the tumblers in a number of different locking cores
which use separate operating keys.
In locking systems of the prior art, the manufacture
and use of separate operating keys and master keys gave rise to
inherent disadvantages. According to the present invention, a
device is provided which may be secured to a preexisting
operating key in order to convert the operating key to a
control key. The adapter may be manufactured according to a
common design for securement to operating keys intended to
operate different locks thereby reducing costs. Replacement of
lost control keys may be simplified in many cases. An improved
method for manufacturing control keys and adapters is also
provided. Other advantages of the present invention will
become apparent upon a reading of the following disclosure.
Drawings are appended hereto which illustrate
embodiments of the present invention. In the drawings,
Fiqure 1 i8 an exploded view of a locking mechanism in
perspective comprising a locking core and a housing;
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Figure lA is a sectional view along line 5-5 in Figure 1,
showing a locking core activated by an operating key and a
control key,
Figure 2 is a plan view of one embodiment of the present
L i nvention;
Figure 3 is an elevation of this embodiment;
Figure 4 is a section of the line A-A in Fiqure 2;
Figure 5 is a plan view of another embodiment of the
present invention; and
Figure 6 is a plan view of yet another embodiment of the
invention.
With reference to Figures 1 and lA, a typical locking
core assembly 60 and a lock housing 70 are shown. The core 60
is received in chamber 74 of the housing. Operating tumblers
61 are received in channel 75. When the operatin~ tumblers are
extended into the channel 75, the locking core will not rotate
within the housing. When operating key 63 with its bitted
portion 100 is inserted into the keyway 50, tumblers 61 are
retracted and the locking core may be rotated. Upon rotation
of the core, pin 60a will displace a spring loaded locking bar
assembly 80 to unlock a storage compartment or other lockable
device. Control tumblers 62 are engaged with channel 76 in the
housing when the control tumblers are extended. When a control
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key is inserted having an extended bitted portion 200, control
tumblers 62 and operating tumblers 61 are all retracted thereby
permitting removal of the entire locking core 60 from the
housing 70.
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It is to be understood that the foregoing embodiment
of a locking core assembly is only one example of a number of
different types of locking systems to which the present
invention may be applied. For example multiple or single
control pins or tumblers may be provided in the locking core.
Alternately, the operating and control tumblers may be situated
in the housing æuch that shear pins housed within the locking
core may be displaced by the bitted portion of the appropriate
key to form a shear line permitting rotation or withdrawl of
the core, as the case may be. All of these variations are
readily understood in the prior art.
Figures 2, 3 and 4 show an embodiment of a control key
estension adapter 200a of the present invention. The adapter
has a body 201 which is integrally connected to a bitted
portion 202 by means of rigid intermediate shaft 204. The
bitted portion 202 or nose-piece includes a raised rib 208
having an edge 210.
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Bitted section lOOa (shown in dashed lines) represents the
bitted shaft of the operating key 100. A sleeve 212 may be
stamped, cast, rolled or otherwise incorporated into the
extension body adjacent the lever end 214 of the body. The
sleeve 212 snugly fits into a corresponding hole 105 in the
operating key. Edge 210 together with sleeve 212 define a
channel for receiving operating key 100.
Sleeve 212 may be manipulated to secure the extension
adapter to the operating key either before or after the
operating key is placed into the channel. For esample, sleeve
212 may be pressed to tightly fit the corresponding hole 105.
Added securement features such as crimping of the terminal ends
of the sleeve may be provided, if desired.
With reference to the foregoing description, it is to
be understood that the control key assembly formed when the
control key estension adapter is secured to the operating key
acts as a control key. It has been found that in the preferred
embodiment, where the estension member i8 made of metal, such
as hardened steel, the nominal thickness 's' of the estension
body may be as little as approsimately 0.010 inches. The
raised rib 208 iB generally of a height which results in a
substantially flush surface when the operating key 100 is
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seated on the extension body. When the upper surface 207 of
the raised rib is substantially even with the corresponding
upper surface 107 of the control key, smooth operation of the
control key assembly within a keyway (such a keyway 50 in Fig.
1) is enhanced.
Edge 210 of raiæed rib 208 provide a means of securing
the bitted portion 202 to the bitted end of the operating key.
In this embodiment the indicated elements act together with the
sleeve 212 and hole 105 arrangement to secure the estension
member to the operating key. Rib 206 is intended to engage
with a corresponding channel in the operating key. It is to be
understood that alternate arrangements and embodiments may be
provided without departing from the intended scope of the
present invention.
Once secure to the operating key rib 206 reduces the
tendency of the bitted portion 202 to the flare away from the
operating key after repeated use in a locking core. It can be
seen that rib 206 provides reinforcement along the shaft 204 of
the estension body. In view of the nominal thickness 's' of
the adapter body, the difference between the operative
thickne8s of the operating key and the control key assembly
will be 'x' provided a tight fit exists between the assembly
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components. It is found that most locking cores will accept
control key assemblies which are moderately thicker that the
operating key without substantially detracting from efficient
operation. Where existing keyway tolerances do not readily
allow variations of 0.010 inches, simple adjustments may be
made during the subse~uent manufacturing process of the cores
or keys thereby permitting such variability.
The control key assembly comprises the operating key
100 and the extension adapter 200a secured together. The
combined bitted segments 100a and 202 are capable of activating
all corresponding operating tumblers 61 and control tumblers
62. The arrangement and configuration of bitting 202 on the
extension adapter may be modified according to the number and
type of control tumblers to be activated in a given application.
Operating keys may have one or more grooves running
along the key shaft portions. Rib 206 is shown in Figures 2, 3
and 4 for engagement with one such groove in a corresponding
operating key. Where more than one such groove is provided in
an operating key, corresponding ribs may be rolled, pressed,
stamped or otherwise formed in the extension member shaft to
engage with such grooves.
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Various means may be employed to secure the e~tension
adapter to an operating key. In Figure 5, an alternate
embodiment of the securement means is shown. A hole 213 is
provided in the extension body 201 having a diameter
substantially equal to the size of the hole 105 in a
corresponding control key. Holes 213 and 105 are intended to
permit placement of the key assembly on a key chain or key ring
when in use. A flange portion 219 is provided at the lever end
of the body. The flange 219 e~tends beyond the terminal edge
101 of the operating key by a distance equal to the combined
widths of flange segment 230 and flange segment 220.
It can be understood that the width of flange 230 may
be selected to correspond to the thickness of the operating key
at its lever end. The flange segments may then be bent, rolled
or otherwise shaped to clamp around the terminal end 101 of the
operating key.
Although only one outline of an operating key is shown
in Figure 2, operating keys having different bitted segments
may be utilized with one standardized extension body. The
width 'w' of the shaft portion 204 may be selected to be
8ufficiently narrow to avoid interference with the bitting on a
range of operating keys. The length and configuration of such
operating keys must be suitable to permit the securement means
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to interact to secure the extension adapter to the various
operating keys.
In another embodiment, the edge 210 of raised rib 208
may provide an indent or channel running substantially along
the length of the edge 210. This channel may be adapted to
more securely receive the corresponding terminal end of the
operating key. Although the foregoing embodiments show a
bitted portion or nose-piece 202 having a solid rib 208, other
embodiments may be used. For example, as shown in Figure 6,
the nose-piece 202 may comprise a raised rib 215 which extendæ
around the outer periperhery of the nose-piece. Ends 216 of
the rib are shown to abut against terminal edge 209 of the
operating key. The height of the rib 215 may be selected to
provide for flush engagement with the upper surface of the
operating key. Where the outer edge 209 of the operating key
is rounded or otherwise shaped, a corresponding channel may be
provided at ends 216 of the rib 215 to enhance positive
engagement between corresponding ends of the key and extension
body.
Rib 215 may be formed from a material stock of uniform
thickness if such stock is used to make the adapter body.
Whereas a collar or sleeve may be stamped, pressed or otherwise
formed at the lever end of the adapter body, rib 215 may also
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be stamped, pressed or otherwise formed at the bitted end of
the adapter body. It is therefore understood that an
inexpensive ada~ter may be provided in this manner. Further
useful modifications of the adapter described herein will occur
to those s~illed in the art and such modifications are intended
to be covered by the following claims.
4382b/3-12
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