Note: Descriptions are shown in the official language in which they were submitted.
The present invention relates to cylinder locks and
more particularly to keys therefor.
Known cylinder locks employing a conventional barrel
require the use of upper pins which bear against the locking
pin and bias same toward the keyway. Thus the barrel is not
self contained which is a disadvantage. In particular the
use of upper pins increaes the size of the lock. Still
further J most cylinder locks do not offer a large number of
possible lock combinations which has the disadvantage that
the locks are more easily picked while it limits the number
of combinations available to users. Additionally
conventional keys, due to their height which is required for
strength, increase the size of the lock by requiring the use
of upper pins.
Where large combinations are available it has been
found that these types of cylinder locks employ a large
number of different parts and accordingly are generally
expensive to manufacture due to their complexity.
It is still further desirable in locks generally that
there be control over the key blanks since it is a
disadvantage of known locks that the keys are too easily
reproduced thus greatly reducing the security of the lock.
It is an object of the present invention to overcome
or substantially ameliorate the above disadvantages.
There is disclosed herein a key blank of generally
"V-shaped" transverse cross~section so as to provide two
longitudinally extending transversely converging key blades
joined by a longitudinal base.
There is also disclosed herein a method of forming a
key, said method comprising the steps of
(a~ providing a key blank of generally "V-shaped"
transverse cross-section so as to define two longitudinally
extending transversely converging key blades joined by a
longitudinal base;
(b) cutting a key profile in at least one of the
blades so as to provide at least one recess extending
inwardly from the edge of the blade; and
(c) bending the blades toward each other so as to
define in combination with the base a key of generally
"U-shaped" tra~sverse cross-section.
A preferred form of the present invention will now be
described by way of example with referençe to the accompanying
drawings, wherein:
Figure 1 is a schematic perspective parts exploded
view of a barrel for a cylinder lock,
Figure 2 is a schematic parts exploded view of a
further barrel to that of Figure l;
Figure 3 is a schematic perspective view of a housing
to receive the barrel of Figures 1 and 2;
Figure 4 is a schematic side elevation of a key
adapted to be used with the barre].s of Figures 1 and 2 with
the key engaged by locking pins;
Figure 5 is a schematic perspective view of the key
of Figure 4;
Figure ~ is a schematic perspective view of a barrel
and front portion of a cylindrical lock;
Figure 7 is a schematic perspective view of a further
barrel and front portion of a cylindrical lock;
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3~ 3
Figure 8 is a plan view of a generally planar key
blank;
Figure 9 is an end elevation of the blank of Figure 8
sectioned along the line 9-9;
Figure 10 is a plan view of the blank of Figure 8
partly deformed so as to provide an intermediate key blank;
Figure 11 is an end elevation of the blank of Figure
10 sectioned along the line 11-11;
Figure 12 is a plan view of a key formed rom the
intermediate key blank of Figure 11; and
Figure 13 is an end elevation of the key of Figure 1
sectioned along the line 12-12.
In Figure 1 there is schematically depicted a barrel
10 of a cylinder lock, which barrel 10 is adapted to be
located within the housing 11 of Figure 3~ The barrel 10
includes a generally cylindrical body 12 having end faces 13
and 14. Formed in the body 12 is a keyway 15 which extends
longitudinally inwardly from the face 14 to adjacent the face
13. The keyway 15 has a configuration adapted to receive
particularly the key of Figures 4 and 5, however it may be
altered to fit any one of the keys depicted in Figures 6 to
9.
Extending inwardly from the outer cylindrical
periphery of the body 12 are a plurality of bores 16 which
are divided into two longitudinally extendiny sets 16A and
16B. Additionally the bores 16 are arranged in pairs
consisting of a bore from each set. Slidably received within
each bore is a locki.ng pin 17, which locking pins are divided
into sets 17A and 17B. The locking pins 17A and 17B are held
in a spaced parallel relationship by a plate 18 which in
combination with the internal surfaces of the bores 16,
restrict the locking pins 17 to moviny in a direction
generally perpendicular to the longitudinal axis of the body
12.
The body 12 is further provided with two
longitudinally extending recesses 19 which are adapted to
receive locking bars 20 which have locking projections 21.
The locking bars 20 are biased to a radially o~ter position
by means of springs 22. The locking bars 20 are slidably
received within the recesses 19 so as to be movable from a
radially inner position allowing rotation of the barrel 10 to
a radially outer position engaged within the grooves 23 (Fig.
3) formed on the internal surfaces of the housing llo In
this radially outer position the barrel 10 is prevented from
rotating by the locking bars 20.
Each of the pins 17 is provided with a recess 24
which is dimensioned to receive a locking projection 21 so
that upon location of the recesses 24 in the correct
position, the corresponding locking projection is engageable
therein. Additionally each pin 17 may be provided with a
dummy recess 25 which is provided to hinder picking of the
lock.
Upon a key of correct configuration being inserted in
the keyway 15, each of the pins 17 is located so that the
locking projections 21 are receivable within the recess 24
thereby allowing the locking bars 20 to move to a raclially
inner position. Thus the barrel 10 may be rotated. If the
recesses 24 are not all correctly aligned, then the locking
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bars are prevented from moving thus retaining the barrel
10 in a locking position. As can be seen from Figures 1
and 3, the locking bars 20 are provided with converging
surfaces 26 which cooperate with converging surfaces 27
forming the groove 23 to force the locking bars radially
inwardly. The locking pins :L7 are biased to a position
projecting inwardly of the keyway 15 by means of springs
28 which bear against the locking pins 17 and a cover
plate 29~
Turning now to Figure 2 wherein there is
schematically depicted a barrel 30 which is of very
similar construction -to the barrel 10 of Figure 1. The
difference being that the barrel 30 has a keyway 31
provided with longitudinally extending flutes 32 which
again increases the number of combinations available for
the lock. Additionally there is provided further pins
33 which are adapted to engage an annular groove formed
on the internal surfaces of the housing 11. These
2S further pins are adapted to retain the barrel 30 within
the housing 11 until a key of correct combination is
inserted allowing retraction of these further pins 33.
The pins 33 are slidably received within passages 3~
formed in the body 12 with a spring 35 being provided to
bias the pins 33 to their radially outer position
retaining the barrel 30 wikhin the housing 11. The pins
33 are moved radially inwardly by cooperating cam
surfaces on an internal surface on a surrounding
housing. More particularly, the housing 11 oE Figure 3
could be provided with the cooperating cam surfaces if
so required.
3~
Turning now to Figures 4 and 5, there is
schematically depicted a key 40 of generally U-shaped
transverse cross section so as to have upwardly
extending key blades 41 ~oined by a base 42. There is
schematically illustrated in E'igure 4 two locking pins
17 engaged with the teeth of the blades 41 to that the
passages 24 are aligned ....
/
/
... . _ _ .. _, . . _
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-6a~
~ ~a~
thus allowing entry of the locking projections 21~ The key
40 is also provided with longitudinally extending flutes and
ridges 43 adapted to increase the number of combinations
a~vailable to the lock. It should be particularly appreciated
that the teeth 44 formed in the blades 41 are separated by
valleys 45 which may extend downwardly to a limit position
adjacent the base 4.~. By providing the key 40 with blades 41
joined by base 42, the volleys may extend to adjacent the
base 42 without the key 40 being weakened to an extent such
that it is easily deformed during use.
A particular feature provided in the key 40 is the
leading portion 46 which is substantially of a chisel
configuration enabling the barrel 10 to be self contained in
that outer locking pins are not required. By providing the
key 40
with th~ leading portion 46, the locking pins 17 may extend
further into the keyway 15.
A further advantage of the key 40 in that the valleys
45 are more easily formed since the blades 41 are in a spaced
parallel relationship.
Turning now to Figure 6, there is schematically
depicted the barrel 60 of a cylindrical lock. The barrel 60
has a front face 61 which defines a key slot 63. The key
slot 63 is shaped so as to accommodate a wide range of key
configurations of the type suitable for the barrel 60. The
front face 61 is further provided with a transversely
extending 510t which is adapted to receive a key selection
member 64 which has a key slot 65 which is aligned with the
slot 63 when the member 64 is located within the~ slot 62. By
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roviding an assembly member 64 r a standard barrel 60 may be
provided with individual key combinations being selected by
interchanyeable key selection members 65.
Turning now to Figure 7, the barrel 66 is similar to
that of Figure 11 in that it is provided with a removable
front portion 67. Further, the barrel 66 .is provided with a
key slot 68 adapted to receive a large variety of key
configurations which are suitable to be used with the barrel
60. Additionally, the barrel 60 is provided with a central
cylindrical aperture 73 adapted to receive a cylindrical
projection 74 forming part of the front portion 67O
Additionally, there is provided a passage 70.extending
through the cylindrical projection 74 which is aligned with
passages 71 formed in the barrel 66 to allow the insertion of
a pin 72 to retain the front portion 67 in its operative
position.
The front portion 67 (which acts as a key selection
member) has a key slot 69 which is adapted to select a
particular key configuratlon. Accordingly the barrel 66 is
adapted to be used as a standard barrel with particular key
configurations being selected by the front portion 67.
Finally witIl reference to Figures 9 to 12 wherein
there is schematically depicted the method of forming a key.
Particularly with reference to Figures 8 and 9, the initial
Icey blank 50 is provided with a blade portion 51 and a head
portion 527 The blade portion 51 has longitudinal recesses
or rib~ 53 which may be varied to alter the combination
provided by the key. These recesses or ribs 53 would match
the flutes 32 of Figure 2 or the configuration of the key
slot of the key selection members 64 and 67 of Figures 6 and
7. The head portion 52 is provided with recesses or holes 54
to securely engage a plastic key head.
It is proposed to provide locksmiths with
intermediate key blanks as shown in Figures 10 and llo
Accordingly the blank 50 is bent about two longitudinally
extending axes so as to provide an intermediate key blank 50A
having a blade portion 51 with a "V-shaped" transverse
cross-section. Thus the intermediate blank 50A has key
blades 55 joined by a base 56~ As can be seen in Figures 10
and 11 the head portion 52 is also bent so as to provide the
head parts 57.
It is proposed to limit the reproduction of keys
according to this specification by selectively providing
bending machines which will receive only a particular
intermPdiate key blank~ Accordingly a particular locksmith
will be limited to selling a predetermined configuration as
far as grooves or ridges 53 are concerned.
Finally the finished key 50B is formed by cutting key
profiles in the blades 55 and then further bending the blades
so as to provide the key 50B with a substantially "U-shaped"
transverse cross-section. ~dditionally a plastic head would
be securely located between the head portions 57.
The blank 50 is also provided with two grooves 57
which extend a:Long the two longitudinal axes about which the
blank 50 is bent. The grooves 57 aid in the accurate bend of
the blank 50 to form the intermediate blank 50A. 'rO further
aid in bending the blank 50A, the grooves 57 are dimensioned
so as to not be totally closed when the intermediate blank
3~
50A is formed. The remaining unclosed part of the grooves 57
enables the easy forma~ion of the key 50B.
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