Note: Descriptions are shown in the official language in which they were submitted.
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"BOLT LOCKING APPARATUS"
This lnvention relates to bolt locking apparatus
for use as the striker component of a latch or lock
mechanism. In a most suitable application, the
invention is also concerned with a security lock
5 assembly especialIy suitable for doors.
The invention provides novel bolt locking
apparatus comprising: a striker unit a~apted for
mounting on a door jamb, which unit defines a cavity
: to receive a lock bolt, latch means mounted for
; 10 movement to an operative position protruding into said
cavity in which the latch means is engagable with the
bolt to prevent its withdrawal from the cavity, and
means to drive the latch means to said operative
position.
Advantageously, the apparatus further comprises
means responsive to receipt of a lock bolt in the
cavity to activate said drive means.
The responsive means preferably includes a
magnetically operable switch mounted adjacent the bolt
20 cavity: it may, for example, comprise a reed switch,
advantageously encased in a solid medium behind an
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inner bounding wall for the bolt cavity. The reed
would typically then be movable in a small elongate
hollow in the medium. For operating the switch, the
bolt is provided with a magnetized element, preferably
5 encased in a spherical or cylindrical core within the
bolt. The core may be rotatably disposed within the
bolt to thwart cutting through of the bolt and/or
removal of the magnetized element.
Said structure may comprise a me~tal striker plate
10 with a rectangular bolt cavity to receive the lock
bolt of a deadbolt mechanism. The movable latch means
engagable with the bolt may be a pin, rod or the like,
e.g., a cylindrical rod, adapted to engage in a hole
in the bolt and preferably arranged so that it tends
15 to fall ~rom the bolt cavity under gravity unless held
in its operative position. A suitable helical spring
may be provided to augment the gravity bias on the
rod.
The drive means preferably includes a solenoid
20 which is energizable, preferably in response to
receipt of lock bolt in the cavity, to drive the latch
means, directly or indirectly, into locking engagement
with the bolt and to retain it in such locking
engagement.
Further switches are advantageously provided for
indicating to a remote control panel whether the bolt
is in the cavity~and whether the latch means is in its
operative position.
The invention will be further described, by way
30 of example only, with reference to the accompanying
drawings, in which:
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Figure 1 is a vertical cross-section through
a closed door fitted with a security lock assembly
including bolt locking apparatus in accordance with
the invention;
Figure 2 is a rear elevational view of the
striker assembly incorporating the bolt locking
apparatus;
Figures 3 and 4 are cross-sections on the
lines 3-3 and 4-4 in Figures 2 and 3 respectiYely;
Figure 5 is a cross-section on the line 5-5
in Figure 2, but with the locking pin shown retracted;
and
Figure 6 is an enlargement of the central
area of Figure lo
The illustrated security lock assembly, fitted to
a door leaf 5 and door jamb 8, includes a deadbolt
latch mechanism 12, having a rectangular bolt 14, in
leaf 6, and a striker assemhly 16 defining a striker
plate 18 and bolt cavity 20, manufactured as a single
20 unit adapted for mounting in the jamb 8. Screw holes
16a are provided for this purpose.
Deadbolt latch mechanism 12 is of a conventional
construction apart from the bolt 14 and, except for
this aspect which will be detailed hereinafter, will
25 not be further described. It is represented in Figure
1 by rectangle 12a.
Striker plate 18 is of L-section steel. Bolt
cavity 20 is defined by a box protrusion 22 cast
intregally with the striker plate. The narrower
30 flange 19 of pla~e 18 carries the usual bolt lead ramp
24 adjacent cavity 20.
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The bolt locking apparatus, which constitutes a
preferred e~bodiment of the invention, is mounted
behind the striker plate 18. The principal components
of the apparatus include latch means comprising a
5 slidable bolt locking pin 26, a drive solenoid 28 for
the pin, a pair of reed switches 30, 50 encased in a
solid resin medium 32 at the rear of bolt cavity 20,
and a switching relay 34 operated by reed switch 30
for setting the state of the solenoid and thereby the
10 position of pin 26. Reed switch 30, relay 34 and
solenoid 28 together constitute means responsive to
receipt of the bolt in the cavity to drive pin 26 to
an operative position in the cavity in engagement with
the bolt 14 to prevent withdrawal of the bolt from the
15 cavity. For enhanced clarity, electrical wlring
connections are not fully detailed in the drawings,
although the leads for reed switches 30, 50 are
depicted at 43.
With reference in particular to Figure 4, reed
20 switches 30, 50, comprise respective reeds 31, 51 in
elongate hollows 33, 53 extending between contact sets
35, 55 cast in medium 32. Medium 32 is fixed behind a
back plate 36 for cavity 20 provided by a bracket 38
(Figure 3). Bracket 38 is adjustably mounted by small
25 bolts 39 to a plate 40 projecting integrally from
striker plate 18 adjacent cavity 20. Media 32 is
adhered to bracket 38 and is further retained by
return lugs 42 at the top and bottom o~ plate 36.
Reeds 31, 51 are of a magnetically sensitive
30 metal and are operated, to open the cont2cts 35, 55,
by a magnetized slug 44 (Figures 1 and 6) in bolt 14.
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Slug 44 is encased in a spherical core 46, which is in
turn freely rotatable with all deyrees of freedom, in
a complementary cavity in the bolt so that any cutting
implement applied to the bolt will in due course
5 stri~e the sphere and indefinitely rotate it rather
than cut it through. The core 46 thus thwarts both
cutting of the bolt and removal of the magnetized
slug.
Pin 26 is one of a pair 26, 27 fixedly coupled by
a horizontal plate 48. The pins are firmly but freely
slidable through respective apertures in a rearwardly
projecting flange 61a behind striker plate 18. Pin 26
projects through a matching aperture 25 in box 22 and
is slidable upwardly to an operative position in which
it firmly engages in a complementary hole 56 in the
underside of bolt 14. When not held in this operative
position, the assembly of pins 26, 27 and plate 48
tends to fall under gravity to withdraw pin 26 from
cavity 20. A helical compression spring 62 about pin
26 between box 22 and plate 48 augments the gravity
bias.
The lower end of pin 27, which is of course
shorter than pin 26, abuts a magnetically sensitive
rod 64 which is surrounded by the coil 29 of solenoid
28. When the solenoid is not energi~ed, the enlarged
bottom 65 of rod 64 rests on a lower flange 61b behind
striker plate 18.
The space above cavity 20 is occupied by a small
circuit board 66 with multi-point connector 68 and the
30 aforementioned relay 34. As already foreshadowed, the
contact set 35 of r~ed switch 30 is connected for
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operating relay 34. The contact set 55 of reed switch
50 is coupled via connector 68 to a remote central
monitoring control, not shown, at which the state of
the reed switch would be indicated in any suitable
5 manner, such as by a light.
A third reed switch 70 is mounted to plate 40
under bracket 38 but is mechanically rather than
magetically operated. The external reed 72 of this
switch is engayed by plate 48 as it nears the top of
its upward travel and reed switch 70 may thus be
employed to indicate at the remote control that pin 2
is in an opexative, bolt engaging position.
The operation o~ the security lock assembly will
now be reviewed. When the door leaf 6 is shut and the
bolt 14 thrown, the receipt of the bolt into cavity 20
is sensed by both reed switches 30, 50 in that the
magnetized slug 44 changes the state of the switches.
Switch 30 thereby triggers relay 34 to energize
solenoid 28. Rod 64 is propelled upwardly against pin
27 and the pin 26 thereby driven against gravity and
spring 62 into the hole 56. Bolt 14 is thereby
positively and physically locked into the striker
cavity. Switch 50 will have transmitted a sisnal to
the control monitor 80 to indicate that the bolt has
entered striker cavity 20, while plate 48 will have
operated switch 70 to transmit a further signal
confirming that pin 26 is in its operative position.
This action will have taken place entirely
automatically and thus any person who has passed
through into a security area and shut the door will be
trapped in the security area and will only be able to
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depart on withdrawal of the power supply to the
solenoid by appropriate switching at the central
control. Moreover r consequent unlocking and
withdrawal of the bolt are separately monitored by
switches 70 and 50.
It will be noted that the security provisions do
not prevent opening the door in an emerger.cy. In the
event of a fire or other emergency in an installation
with multiple doorways fitted out as illustrated, the
power may be simultaneously withdrawn fr~m the
solenoids of all doorways to permit the withdrawal of
the respective bolts from their striker cavities.
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