GB2133454A

GB2133454A - Bolt locking apparatus

Info

Publication number: GB2133454A
Application number: GB08314603A
Authority: GB
Inventors: Michael Trevor Mackle
Original assignee: Wormald International Ltd
Current assignee: Wormald International Ltd
Priority date: 1983-01-10
Filing date: 1983-05-26
Publication date: 1984-07-25
Also published as: EP0113699A3; DE3467206D1; EP0113699A2; ATE30616T1; GB8314603D0; EP0113699B1; GB2133454B

Abstract

When latch bolt 14 engages in cavity 20 of its keeper, it is automatically locked by pin 26 lodging in recess 56. The bolt carries a magnetic slug 44 encased in a freely rotatable ball 46. The presence of the bolt is sensed by the action of the magnetic field on two reed-switches located behind back plate 36; one of these actuates solenoid 28 to drive rod 64 upwards to move pin 27 and, via plate 48, to drive pin 26 into its locking position. The other reed- switch operates a signal to show that the bolt is locked. The bolt may be released by a switch at a central console. <IMAGE>

Description

1 GB 2 133 454 A1

SPECIFICATION Bolt locking apparatus

This invention 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 locking system for doors.

The invention provides bolt locking apparatus comprising:

structure defining a bolt cavity; latch means mounted for 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 responsive to receipt of the bolt in the cavity to drive the latch means to said operative position.

The responsive means preferably includes a magnetically operable switch mounted adjacent the bolt cavity: it may, for example, comprise a reed switch, advantageously encased in a solid medium behind an 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 encased in a spherical or cylindrical core within the bolt. Advantageously, the core is rotatably disposed within the bolt to thwart cutting through of the bolt and/or removal of the magnetized element.

Said structure may comprise a metal striker plate with a rectangular bolt cavity for the bolt of a deadbolt mechanism. The inner extremity of the bolt cavity may be closed by a bracket defining an end plate for the cavity, behind which is fixed said 100 solid medium. The solid medium may be a suitable resin.

The movable latch means engagable with the bolt is preferably a pin, rod or the like, e.g., a cylindrical rod arranged so that it tends to fall from. 105 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 responsive means preferably further 110 includes a solenoid which is energizable, in response to said receipt of the bolt in the cavity, to drive the latch means, directly or indirectly, into locking engagement with the bolt.

Further switches are advantageously provided 115 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 former provision may be met by a second reed switch encased in the solid medium while the latter may 120 be a third reed switch mechanically operated by a plate or arm which moves with the latch means.

The invention will be further described, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 is a vertical cross-section through a closed door fitted with a security locking system 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 respectively; 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 1.

The illustrated security locking system, fitted to a door leaf 6 and doorjamb 8, includes a deadbolt latch mechanism 12, having a rectangular bolt 14, in leaf 6, and a striker assembly 16 having a striker plate 18 and bolt cavity 20, manufactured as a single unit for mounting in the jamb 8.

Deadbolt latch mechanism 12 is of a conventional construction apart from the bolt 14 and, except for this aspect which will be detailed hereinafer, will 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 integrally with the striker plate. The narrower flange 19 of plate 18 carries the usual bolt lead ramp 24 adjacent cavity 20.

The bolt locking apparatus, which constitutes a preferred embodiment of the invention, is mounted behind the striker plate 18. The principal components of the apparatus include latch means comprising a slidable bolt locking pin 26, a drive solenoid 28 for the pin, a pair of reed switches 30, 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 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 cavity. For enhanced clarity, electrical wiring connections are not fully detailed in the drawings, although the leads for reed switches 30, are depicted at 43.

With reference in particular to Figure 4, reed 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 adjustabiy mounted by small 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 of plate 36.

Reeds 31, 51 are of a magnetically sensitive metal and are operated, to open tile contacts 35, by a magnetized slug 44 (Figures 1 and 6) in bolt 14. Slug 44 is encased in a spherical core 46, which is in turn freely rotatable with all degrees of freedom, in a complementary cavity in the bolt so that any cutting implement applied to the bolt will in due course strike the sphere and indefinitely 2 GB 2 133 454 A 2 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 by65 a horizontal plate 48. The pins are firmly but freely slidable through respective apertures in a rearwardly projecting flange 61 a behind striker plate 18. Pin 26 projects through a matching aperture 25 in box 22 and is slidable upwardly to 70 an operative position in which it firmly engages in a complementary cavity 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 1.5 20. A helical compression spring 62 about pin 26 75 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 energized, the enlarged bottom 65 of rod 64 rests on a lower flange 61 b behind striker plate 18.

The space above cavity 20 is occupied by a small circuit board 66 with multi-point connector 68 and the aforementioned relay 34. As already foreshadowed, the contact set 35 of reed switch 30 is connected for 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 manner, such as by a light.

A third reed switch 70 is mounted to plate 40 under bracket 38 but is mechanically rather than magnetically operated. The external reed 72 of this switch is engaged 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 26 is in an operative, bolt engaging 100 position.

The operation of the security locking system 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, 50 105 in that the magnetized slug 44 changes the state of the switches. Switch 30 thereby triggers relay 34 to engergize solenoid 28. Rod 64 is propelled upwardly against pin 27 and the pin 26 thereby driven against gravity and spring 62 into the cavity 110 56. Bolt 14 is thereby positively and physically locked into the striker cavity. Switch 50 will have transmitted a signal to the control monitor 80 to indicate that the bolt has entered striker cavity 20, while plate 48 will have operated switch 70 to 1 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 depart on withdrawal of the power supply to the solenoid by appropriate switching of the central control. Moreover, 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 emergency. 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 from the solenoids of all doorways to permit the withdrawal of the respective bolts from their striker cavities.

Claims

1. Bolt locking apparatus comprising:

structure defining a bolt cavity; latch means mounted for movement to an operative position protruding into said cavity in which the latch means is engageable with the bolt to prevent its withdrawal from the cavity; and means responsive to receipt of the bolt in the cavity to drive the latch means to said operative position.

2. Bolt locking apparatus according to claim 1 wherein the responsive means includes a magnetically operable switch mounted adjacent the bolt cavity.

3. Bolt locking apparatus according to claim 2 wherein the switch is encased in a solid medium behind an inner bounding wall for the bolt cavity.

4. Bolt locking apparatus according to claim 3 wherein said switch is a reed switch, the reed being movable in a small elongate hollow in the medium.

5. Bolt locking apparatus according to any preceding claim wherein said structure comprises a metal striker plate within a rectangular bolt cavity for the bolt of a deadbolt mechanism.

6. Bolt locking apparatus according to any preceding claim wherein the movable latch means engageable with the bolt is a pin, rod or the like arranged so that it tends to fall from the bolt cavity under gravity unless held in its operative position.

7. Bolt locking apparatus according to claim 6 further including a helical spring to augment the gravity bias on the latch means.

8. Bolt locking apparatus according to any preceding claim wherein said responsive means further includes a solenoid which is engergizable, in response to said receipt of the bolt in the cavity, to drive the latch means, directly or indirectly, into locking engagement with the bolt.

9. Bolt locking apparatus according to any preceding claim including one or more further switches for indicating to a remote control panel whether the bolt is in the cavity and/or whether the latch means is in its operative position.

10. Bolt locking apparatus according to any one of clairns2 to4 in combination with a latch mechanism having a bolt provided with said R 1 3 GB 2 133 454 A 3 magnetized element.

11. The combination of claim 10 wherein the magnetized element is encased in a spherical or cylindrical core within the bolt.

12. The combination of claim 11 wherein the core is rotatably disposed within the bolt to thwart cutting through of the bolt and/or removal of the magnetized element.

Printed for Her Majesty's Stationery Office by the Courier Press. Leamington Spa, 1984. Published by the Patent Office, Southampton Buildings, London, WC2A lAY, from which copies may be obtained.

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