Note: Descriptions are shown in the official language in which they were submitted.
CA 02826841 2013-09-26
Attorney Ref: 1178P002CA01
LOCK MECHANISM
TECHNNICAL FIELD
This invention relates to a lock mechanism. It also relates to
a lock
incorporating the lock mechanism.
BACKGROUND
A typical lock comprises a lock bolt that is received within a keep when the
lock
is activated. When the lock is deactivated the lock bolt can be withdrawn from
the
keep. A lock mechanism is typically used to selectively restrict or control
movement of
a lock and/or control the lock bolt.
Certain locks and lock mechanisms, such as those for key boxes or safes and
the
like, are required to be particularly robust. These types of locks must be
able to
withstand large forces, particularly when attacked, yet still operate smoothly
and
reliably.
SUMMARY OF THE INVENTION
According to a first aspect of the invention we provide a lock mechanism
comprising a control element arranged for rotation about an axis between an
active
position and an inactive position, the control element including a control
head having at
least one axially extending projection, the lock mechanism further comprising
a lock
element that is axially aligned with the control element and includes a lock
element
head, the lock element head having at least one axially extending projection,
the
projection(s) of the control head and the projection(s) of the lock element
head arranged
such that in the active position, the lock element and control element are
held apart by
the projections and in the inactive position, the projections can mesh
together to permit
axial movement of the lock element relative to the control element.
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This is advantageous as the lock mechanism can be constructed such that it is
very robust for its size. The intermeshing projections provide an easy to
manufacture
and reliable way to control the motion of the lock element.
Preferably the lock element comprises an elongate body having the at least one
projection at one end and a lock bolt at an opposed end, the lock bolt adapted
to be
received within a keep of a lock. Alternatively, the lock element or lock bolt
may be
adapted to actuate a further mechanism of greater strength, for example.
Preferably, at least one of the projections includes a narrower tip that is
narrower
than the remainder of the projection or tapers. This will allow the
projections to mesh
together more easily as the tip, which could be conical or frustoconical,
guides the
projections to intermesh.
Preferably the control head has at least two axially extending projections and
the
lock element head may have a complementary number of axially extending
projections.
Preferably, the control head is castellated and thus the castellations form
the at
least one projection. Preferably the lock element head is castellated, the
castellations
on the lock element head being complimentary to the castellations on the
control head.
Preferably the castellations are arranged in a ring.
Alternatively, one of the control head and lock element head may comprise a
single projection having bores therein, the bores arranged to receive
complimentary
pins on the other of the control head and lock element head when in the
inactive
position such that the pins are received within the bores and thus mesh
together, and in
the active position, the pins are not aligned with the bores and the control
element and
lock element are held apart.
Preferably the projection on the control head or the projection on the lock
element head is shaped such that the rotational motion of the control element
is
converted to axial motion of the lock element. Thus, the projection may have a
lead-in
portion inclined to the axial direction arranged to bear against the other
projection such
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that rotation of the control element moves the lock element in the axial
direction. This
is advantageous as rotation of the control element can be arranged to drive
the control
element and lock element apart so that the lock element can engage a lock
keep, for
example.
Preferably the control element and the lock element are received within a
housing and are axially slidable therein, the lock mechanism including a
biasing
element to urge the control element and lock element apart. Preferably the
housing
forms a guide such that the control element and lock mechanism can move
axially
relative to one another. This arrangement is advantageous as the lock element
and
control element can "float" in the housing, which has been found to result in
a more
reliable mechanism as tolerances do not need to be strictly controlled.
Preferably the housing comprises an abutment end plate at one end arranged to
contact the control element. Preferably the abutment end plate is adapted to
form a
mount for a motor for rotating the control element between the active and
inactive
positions. The end plate is advantageous as it transfers forces applied to the
control
element to the housing rather than the forces being transferred to the motor.
Preferably the control element comprises a tubular body having the control
head
at one end.
Preferably, the tubular body of the control element is arranged to receive a
motor
for rotating the control element between the active and inactive positions,
wherein the
motor is mounted to an abutment end plate of the housing. This is advantageous
because any force applied to the control element, will be transferred to the
abutment
plate rather than through the motor.
Preferably the motor comprises a spindle to engage an aperture in the control
element, the aperture and spindle being arranged such that the spindle is
axially slidable
within the aperture. This is advantageous as the spindle is shaped such that
it can rotate
the control element, but it can also slide axially. This helps to isolate the
motor from
any forces experienced by the control element, when the lock mechanism is
attacked,
for example.
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Alternatively, the abutment plate may include an aperture for receiving a rod
that, at a first end, engages the control element and at a second end is
coupled to a
motor for rotating the control element that is mounted outside of a housing of
the lock
mechanism. This is advantages as the motor is separate from the remainder of
the lock
mechanism. This isolates the motor from forces subjected to the lock
mechanism,
especially when the rod is slidably received within the control element.
Preferably the housing comprises an aperture in one end to allow the lock
element to project from the housing.
Preferably the lock mechanism includes a withdrawal means for withdrawing the
lock element when the control element is in the inactive position. The
withdrawal
means may comprise a slider projecting from the lock element, the slider
adapted to be
moved by a user to withdraw the lock element. The slider may be actuated by a
handle.
Alternatively, the withdrawal means may comprise a withdrawal motor arranged
to
withdraw the lock element. This is advantageous as the withdrawal motor can be
controlled in combination with the motor that operates the control element so
that the
two motors can operate together or sequentially.
In a further embodiment, the lock mechanism may include two lock elements
adapted to project from opposed ends and the control element may include at
least one
projection at both ends and a middle support plate may provide support to a
midsection
of the control element. This is advantageous as the middle support plate can
be
connected to a housing and engage a groove in the midsection of the control
element.
The middle support plate may provide a mount for a motor.
According to a second aspect of the invention we provide a lock having the
lock
mechanism of the first aspect of the invention, the lock element comprising a
lock bolt
at one end, opposed the lock element head, for engaging a keep.
This is advantageous because the lock mechanism can easily be integrated into
a
lock. The lock may be integrated in a door, a strong box, an electronic
padlock, a
deadbolt, a deadbolt lock or a key box, for example.
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Attorney Ref.: 1 1 7 8P002CAO 1
Preferably the lock includes withdrawal means for withdrawing the lock bolt
from the keep.
Preferably, the lock element and control element are arranged such that the
throw of the lock bolt is determined by the depth of the projections. Thus,
the amount
the projections can mesh together controls the throw of the lock bolt. This is
advantageous as the lock mechanism only requires a simple modification to suit
the
desired throw of the lock bolt. Preferably the lock bolt is fixedly secured to
or integral
with the lock element.
Preferably the lock bolt comprises a rod having a substantially .flat edge for
engaging the keep; a cylindrical member; or a ball bearing.
In a third aspect, this document discloses a lock mechanism comprising a
control element arranged for rotation about an axis between an active position
and an
inactive position, the control element including a control head having at
least one
axially extending projection, the lock mechanism further comprising a lock
element
that is axially aligned with the control element and includes a lock element
head, the
lock element head having at least one axially extending projection, the at
least one
axially extending projection of the control head and the at least one axially
extending
projection of the lock element head arranged such that in the active position,
the lock
element and control element are held apart by the at least one axially
extending
projection and in the inactive position, the at least one axially extending
projection can
mesh together to permit axial movement of the lock element relative to the
control
element, in which the lock element comprises an elongate body having the at
least one
projection at one end and a lock bolt at an opposed end.
BRIEF DESCRIPTION OF THE DRAWINGS
There now follows by way of example only a detailed description of the present
invention with reference to the accompanying drawings, in which;
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Figure 1 shows a cross sectional view of an embodiment of the lock
mechanism;
Figure 2 shows a side view of the lock mechanism with the control element in
an active position;
Figure 3 shows a side view of the lock mechanism with the control element in
an inactive position; and
Figure 4 shows an embodiment of a locking system incorporating the lock
mechanisms of Figures 1 to 3.
DETAILED DESCRIPTION
A lock mechanism 1 is shown in the Figures 1 to 3, which is arranged to be
integrated
into a key box. It will be appreciated that the lock mechanism 1 is perfectly
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Attorney Ref: 1178P002CA01
suited for integration into other arrangements where a robust and reliable
lock
mechanism is required.
The lock mechanism 1 comprises a control element 2 arranged for rotation about
an axis A between an active position (shown in Figure 2) and an inactive
position
(shown in Figure 3). The control element 2 includes a control head 3 at one
end having
four circumferentially spaced projections 4a-d extending axially therefrom.
Thus, the
four projections have four gaps therebetween.
The lock mechanism 1 further comprises a lock element 5 that is axially
aligned
with the control element 2 and includes a lock element head 6. The lock
element head 6
faces the control head 3. The lock element head 6 has, at its end, four
circumferentially
spaced projections 7a-d extending axially therefrom. Thus, the four
projections have
four gaps therebetween. The
projections 4a-d of the control head 3 and the
projections 7a-d of the lock element head 6 are arranged such that in the
active position,
the lock element 5 and control element 2 are held apart by the projections 4,
7 and in
the inactive position, the projections 4 and 7 can mesh together to permit
axial
movement of the lock element 6 relative to the control element 2.
The control element 2 comprises a substantially tubular body 8 of circular
cross-
section that is closed at one end by the control head 3. At the opposite end,
the control
element 2 comprises an abutment rim 10. The abutment rim 10 includes a part-
circumferential cut-out 11, which is used to limit the rotational movement of
the control
element 2, as will be described in more detail below. The projections 4 of the
control
head 3 form a ring of castellations. The ring of eastellations define a
central region 12
of the control head 3 adapted to receive a biasing element 13 comprising a
coil spring.
The control head 3 also includes an aperture 14 that connects the inside of
the tubular
body 8 to the central region 12. The aperture 14 is keyed and in this
embodiment is
semicircular in cross-section.
The lock element 5 comprises a substantially cylindrical body 16. The lock
element head 6 extends from a first end of the body 16. The opposed second end
of the
body comprises a bolt 17. The bolt 17 is arranged to fit within a keep (not
shown) of
the key box lock that the lock mechanism is mounted. The lock element 5
includes
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withdrawal means (not visible) that allows the bolt 17 of the lock element 5
to be
withdrawn. The withdrawal means comprises a withdrawal rod that extends
radially so
that the bolt 17 can be withdrawn by a user. The lock element 5 also includes
an
axially facing ledge 19 that surrounds the bolt 17.
The control element 2 and lock element 5 are slidingly mounted within a
housing 18. In particular, the housing 18 provides a guiding channel in which
the
control element 2 and lock element 5 can slide axially. The control element 2
and lock
element 5 are biased apart by the biasing element 13 and therefore "float"
within the
housing 18. The housing 18 has a bolt aperture 17' that allows the bolt 17 to
project
from the housing 18 so that it can engage the keep of the lock when in use.
The bolt
aperture 17' and bolt 17 are keyed to restrict rotation of the bolt 17 and
therefore the
lock element 5. The housing also includes a longitudinal slot (not visible)
that allows
the radially extending withdrawal rod to extend through the housing and move
the lock
element 5 when required.
The housing 18, at an end opposed to the aperture 17', includes an abutment
end
plate 20. The end plate 20 includes a mounting area 21 for a motor 22. The
housing 18
is formed integrally with the abutment end plate 20, although they are shown
as
separate items in the Figures for clarity. The contents of the housing 18 is
thus loaded
therein through the end opposed to the abutment end plate 20 and then an end
cap
including the aperture 17' is affixed to the housing by welding, for example.
The
motor 22 includes a spindle 23 that is received within the keyed aperture 14.
The
spindle 23 is also keyed so that the motor 22 can rotate the control element
2. The
spindle 23, although keyed for rotation, is axially slidable in the aperture
14. The
mounting area 21 is surrounded by a support track 25, which is arranged to
abut the
abutment rim 10. The support track 25 is annular and includes a stop peg 24.
The stop
peg 24 is arranged to project into the cut-out 11 and thus limits the amount
that the
control element 2 can rotate, as the stop peg 24 will contact the sides of the
cut-out 11.
This arrangement is particularly advantageous as any force that is subjected
to the
housing 18 is transferred via the end plate 20 to the housing 18. The motor 22
is
isolated from the force as the control element 2 is arranged to abut the end-
plate and not
bear on the motor 2 and the spindle 23 is axially slidable in the aperture 14.
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Figures 2 and 3 show the lock mechanism 1 with the housing 18 removed to
reveal the position of the control element 2 and lock clement 5 in use. Figure
2 shows
the active position in which the control element 2 and lock element 5 are
biased apart
by the biasing element 13. Accordingly, the control element 2 abuts the
support
track 25 and the ledge 19 of the lock element 5 abuts the housing 18 adjacent
the bolt
aperture 17'. The control element 2 is at a rotational position where the
projections 4a-
d of the control head 2 are aligned with the projections 7a-d of the lock
element head 6.
Thus, the control clement 2 and lock element 5 are restricted from moving
further
axially toward one another. The bolt 17 is maintained in its extended position
where it
extends into the keep of the key box lock (not shown). The stop peg 24 abuts a
first
side of the cut-out 11 in the active position. Any force that is applied to
the bolt 17,
such as if the lock is attacked, will be transferred to the housing 18 or
through the
control element 8 and the end plate 20 to the housing 18. The force on the
motor 22
and spring 13 is kept to a low level so that they arc not damaged. Therefore,
it is
relatively easy and cost effective to manufacture the housing 18, end plate
20, lock
element 5 and control element 2 of robust materials. The arrangement of the
lock
mechanism 1 is particularly advantageous as it reduces the forces on the more
delicate
components, which ensures reliable operation. As the structure transfers force
to the
housing 18, the housing can be made of a strength or thickness to suit the
intended use
for the lock mechanism.
Upon actuation of the motor 22, the control element 2 is rotated through
approximately 45 such that is adopts the inactive position. Accordingly the
stop
peg 24 now abuts an opposed side of the cut-out 11. In the inactive position,
the
projections 4a-d of the control head 2 are aligned with the gaps between the
projections 7a-d of the lock element head 6. Likewise, the projections 7a-d of
the lock
element head 6 are aligned with the gaps between the projections 4a-d of the
control
head 2 so that the projections can move into the respective gaps. The
withdrawal means
rod can then be used to withdraw the lock element 5 axially towards the
control
element 2 such that the projections 4a-d mesh between the projections 7a-d and
vice-
versa. Withdrawal of the control element 2 withdraws the bolt 17 out of the
keep of the
key box, allowing the key box to be opened.
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To lock the lock mechanism, the bolt 17 is returned to the keep, perhaps with
manipulation of the withdrawal means. The biasing element 13 urges the control
element 2 and lock element 5 apart and thus the bolt 17 adopts its extended
position
through the bolt aperture 17'. The projections 4a-d and 7a-d are thus no
longer meshed
together. The motor 22 can then be actuated to rotate the control element 2 to
the
active position in which the projections are aligned end to end.
It will be appreciated that although the control element 2 and the lock
element 5
have been shown having four projections each, they may have more or less
projections
or different numbers of projections. Further, the housing and thus the control
element 2
and lock element 5 are described as substantially cylindrical, although they
could be
alternative shapes provided that relative movement in the axial direction is
possible and
the control element is able to rotate about its axis. Further, the embodiment
of the lock
mechanism 1 described above is for integration into a key box. It will be
appreciated
that the mechanism 1 can be used in any appropriate lock where a high
strength, attack
resistant, simple and reliable mechanism is required. The lock bolt 17 may
comprise a
ball bearing that projects though an aperture 17'. In the inactive position,
the ball
bearing operates as a strike mechanism and can ride into and out of the keep
against the
force of spring 13. When the lock mechanism is in the active position, the
ball bearing
is held, projecting from the lock mechanism, in the keep.
Figure 4 shows a locking system 40 that uses the lock mechanism 1 described
above. The locking system 40 is a security device for remote locking of the
internal or
external doors of a property, possibly in response to the detection of an
unauthorised
intrusion into the building. The locking system 40 in this embodiment
comprises a lock
control panel 41, a first lock mechanism 42 loaded into a first internal door
43 of a
building and a second lock mechanism 44 loaded into a second internal door 45
of a
building.
The lock control panel 41 includes a key panel 46 for receiving the input of a
code, a controller 47 and an antenna 48. The controller 47 is arranged to
receive a code
from the key panel 46 in order to "arm" and "disarm" the controller 47. The
controller
47 also receives input from an intrusion detection device 50, which may
comprise a
Passive Infra Red (PIR) sensor. When the controller is armed, it is adapted to
act on
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the input from the intrusion detection device 50. When it is disarmed it does
not act on
the input from the intrusion detection device 50. The controller acts on the
input by
sending command signals, via the antenna 48, to the first and second lock
mechanisms 42, 44. Accordingly, the controller includes wireless communication
means to communicate with the lock mechanisms 42, 44.
The lock mechanisms 42, 44 are similar and therefore only one lock mechanism
will be described and the same reference numerals arc used to describe
corresponding
parts but with an additional dash when applied to the second lock mechanism 44
and
second door 45. The lock mechanism 42, 44 has a withdrawal means in the form
of a
handle 51, 51'. The handle 51, 51' is able to withdraw the lock bolt 52, 52'
from its
keep 53, 53' when the lock mechanism is inactive. The keep is mounted in a
door
frame 54, 54'. When the lock mechanism is active, the lock bolt 52, 52' is
held in the
keep 53, 53'. The lock mechanism 42, 44 includes a lock mechanism controller
55, 55'.
The lock mechanism controller is arranged to receive command signals from the
controller 47 via an antenna 56, 56'. Thus, the lock mechanism controller 55,
55'
includes wireless communication means. It will be appreciated that the
controllers 55,
55' and antennas 56, 56' are contained with a lock unit that can be
retrofitted to
existing doors in place of the existing lock. This is advantageous as the lock
unit can
be installed simply, with no modification to the door or the aperture in the
door for the
lock. The small size and high strength of the lock mechanism allows the lock
unit to be
a suitable size for retrofit applications.
In use, the lock mechanisms 42, 44 are normally inactive and therefore the
.. doors 43, 45 can be opened by their handles 51, 51'. When a user arms the
locking
system 40 by entering a predetermined code, the controller 47 waits for input
from the
intrusion detection device 50. If an intrusion is detected, the controller 47
sends a
control signal to the lock mechanisms 42, 44, which is received by their
associated lock
mechanism controllers 55, 55'. The lock mechanism controllers 55, 55' cause
the
motors 22 in the lock mechanisms to actuate to move the control element 2 to
the active
position, whereby the doors 43, 45 are locked and the withdrawal of the lock
bolts 52,
52' from their respective keeps 53, 53' is prevented. This will isolate rooms
in the
building from the intruder as the intruder will not be able to move freely
between the
rooms secured by the locking system 40. The locking system 40 can be disarmed
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the doors 43, 45 opened by input of the predetermined code into the key panel
46. The
controller 47 then sends control signals to cause the lock mechanism
controllers 55, 55'
to deactivate their respective lock mechanisms.
It will be appreciated that the above description is only an example of how
such
a locking system could be implemented. For example, there may be more or less
doors
secured; more or less intrusion detection devices; different types of
intrusion detection
device; the use of encrypted control signals; the incorporation of anti-
tampering
features; the incorporation into an burglar alarm system; the use of safety
systems and
panic buttons to prevent legitimate occupants of the building from becoming
trapped
and other changes or enhancements that will be clear to those skilled in the
art. The
main advantage of the locking system is that the locking mechanism of the
invention,
due to its small size and high strength, can be incorporated into doors and
windows to
form locking systems that were previously impractical and/or expensive.
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