GB2218728A - Improvements in or relating to locking mechanisms - Google Patents

Abstract

A secondary unit for a locking mechanism having a primary unit is actuated by a rod (11) extending from the primary unit, the rod (11) being connected via a connector (42) to a slidable plate (46) which carries a cylindrical bolt (51). A pin (44) carried by the connector (42) is received in an elongated slot (55) in a pivotally mounted drive link (52) which has a further elongated slot (53) receiving a guide pin (41) carried by a deadbolt (13) so that sliding movement of the rod (11) causes simultaneous extension or retraction of the deadbolt (13) and cylindrical bolt (51) in mutually perpendicular direction. A spring biased retaining link (37) holds the deadbolt in its extreme extended and retracted positions. <IMAGE>

Description

IMPROVEMENTS IN OR RELATING TO LOCKING MECHANISMS This invention relates to a secondary unit for a locking mechanism.

Locking mechanisms are known which comprise a central primary unit and upper and lower secondary units, connected to the primary units by rods or links. The rods or links are extended or retracted by key operated or other means, i.e. handles, at the primary unit, and movement of the rods or links extends or retracts respective laterally movable deadbolts or latch bolts of the secondary units. With the locking mechanism fitted in a door stile and the door closed, the bolts of the primary and secondary units engage, when extended, respective associated keepers in the door jamb. However a potential intruder can try to force open the door by inserting a tool into the gap between the door stile and the door jamb and levering the door away from its jamb. This may result in some of the bolts being withdrawn, at least partly, from their associated keepers.

An object of the invention is to provide a secondary unit for a locking mechanism which can produce improved security.

According to the invention there is provided a secondary unit for a locking mechanism having a primary unit, the secondary unit comprising means for operatively connecting it to the primary unit, and first and second bolts which are extendable or retractable, in use, by actuation of said connecting means from the primary unit, the extended position of the first bolt being at right angles or substantially at right angles to the extended position of the second bolt.

According to another aspect of the invention there is provided a locking mechanism comprising a primary unit, a connecting member operatively connecting the primary unit to a secondary unit, the secondary unit having first and second bolts, the bolts being retractable or extend able, in use, by actuation of said connecting member from the primary unit, the extended position of the first bolt being at right angles or substantially at right angles to the extended position of the second bolt.

Desirably two secondary units are provided, above and below the primary unit respectively.

The invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a side view of a secondary unit of the invention; Figure 2 is an enlarged, fragmentary side view of the unit of Figure 1, with a side plate removed to show the interior components, Figure 3 is a longitudinal sectional view through the secondary unit of Figure 2, and Figure 4 is an exploded perspective view showing some components of an alternative embodiment of secondary unit.

Figure 1 shows a secondary unit 10 which, in use, is connected by an upper rod 11 to a central, primary unit of a locking mechanism. A second, identical secondary unit would normally also be provided, connected to the primary unit by a lower rod, the secondary units being at the top and bottom respectively, of a wing, such as a door, all three units being recessed into an edge of the door which, in use, in its closed position is in juxtaposition with a frame of the door. In a conventional manner, means are provided at the primary unit for simultaneously extending or retracting the upper and lower bolts.

The unit 10, which will be considered as an upper secondary unit, comprises an aluminium faceplate 12 having a generally rectangular slot through which a deadbolt 13 can be received. Secured to one side of the faceplate 12 is a front plate 14 having a corresponding slot for the deadbolt. The front plate is part of a rectangular housing having side plates 15, 16, a top end plate 17 and a rear plate 18. The housing is open at its lower end. The plates 15, 16 have respective aligned elongated slots 19, 20 therein towards their lower ends, the slots extending parallel to the length of the plates 12 and 18. Nearer their upper ends, the plates 15, 16 have another pair of respective aligned elongated slots 21, 22 therein, these slots lying normal to the slots 19, 20.Above and below the slot 21 on the inner surface of plate 15 are parallel raised strips 23, 24 which terminate just short of the plate 18 in upstanding lugs 25, 26 respectively.

From the lower edge of side plate 15 there extends a guide rib 27 generally parallel to the plate 18 and disposed between the faceplate 12 and slot 19. At a position approximately level with the lower part of the slot 19 the rib 27 terminates at a square pillar 28 which carries a short, internally threaded cylindrical post 29 at its top. The rib 27 is effectively continued, but with greater height, at the upper side of the pillar 28 and has an end part curved round towards the plate 18. The lower end of plate 18 is enlarged to provide an internally threaded pillar 30.

Above the strip 23, a centrally positioned cylindrical post 31 is upstanding from the side plate 15. At one side of the post 31, an internally threaded pillar 32 extends into the housing from the front plate 14.

Above the post 31 and adjacent the rear plate 18 is an internally threaded, cylindrical post 33. The top plate 17 terminates short of the rear plate 18 to form a slot. The side plate 16 has four countersunk screw holes corresponding to the threaded bores in the pillars, 30 and 32 and posts 29, 33 and when fitted on the plates 14, 17 and 18, the side plate 16 can be secured in place by screws 16a engaged in the threaded bores.

The post 33 serves to locate a steel blade spring 34 which has one arm engaging against a rib 35 extending down from the top plate 17. The other arm of the spring 34 is kinked to provide a straight end portion 36a and a short generally arcuate portion 36b for engagement with a deadbolt retaining link 37 which is pivotally carried on the post 31 and bears on the raised strip 23. The link 37 has at its upper end an arcuate part 38 and a straight part 39 and one of these parts engages the corresponding portion 36a or 36b depending on whether the lower end of the pivotal link is towards the plate 14 or 18. The lower end of the link has an elongated slot 40 therein and a guide pin 41 extending out of opposite sides of the deadbolt 13 passes through the slot 40 and into the slot 21.

Similarly at the other side of the deadbolt the pin 41 extends into the slot 22.

Accordingly when the deadbolt is in its extended state, as shown in Figure 2, the pin 41 is at the left hand end of the slots 21, 22 and the slot 40 is at the left hand end of slot 21. The arcuate part 38 engages the arcuate portion 36b of the spring and the spring holds the bolt 13 extended. Should the deadbolt be retracted, it will slide into the housing along the strips 23, 24 and the pin 41 will move to the right hand ends of the slots 21, 22 respectively pushing the slot 40 to the right hand end of slot 21 and pivotting the link 37. The arcuate part 38 will force the spring upwardly as it pivots and thereafter the straight end portion 36a of the spring will bear on the straight part 39 of the link to hold the deadbolt retracted.

Slidably disposed in the housing is a rod connector 42 having a bifurcated lower end 42a for pivotal connection of the upper rod 11 extending from the primary unit of the locking mechanism. The connection is by means of a pivot pin 43. The connector 42 has a guide pin 44 extending out of its opposite sides and engaging in the slots 19, 20 respectively. A nose shaped part 45 of the bifurcated lower end 42a engages the rib 27 and is guided thereby so that the connector 42 can slide longitudinally in the housing in response to extension or retraction of the rod 11. The extent of the sliding movement of the connector is limited by the slots 19, 20.

At its side facing the rear plate 18, the connector is secured to a steel and nickel bolt actuator plate 46.

This securement can be by any suitable means. For example it could be by way of a screw received in a countersunk head in the plate 46 engaging in a threaded bore in the connector 42. Alternatively it could be as in Figure 4 where an extension part 47 on the connector 42 is received in a slot 48 in plate 46 and then subjected to coining and serrated to complete the securement. The plate 46 is received against the plate 18 and is guided by the lugs 25, 26 to pass through the slot between the plates 17, 18. At its end outside of the housing, the plate is bent through 90 in a direction towards the faceplate 12 to provide a short flange 49. To this flange is secured an upstanding, internally threaded cylindrical spigot 50. Into this spigot is engaged a steel cylindrical bolt 51, a threaded end of the bolt being screwed into the spigot.The bolt 51 has a knurled part 51a to assist gripping of the bolt when screwing it into the spigot.

In use, not shown, there is an aligned hole or keeper in an upper frame of the door to receive the upper end of the bolt 51 when it is extended in the closed position of the door.

An interconnection between the deadbolt 13 and the connector 42, and thus between the deadbolt and the rod 11 is provided by a drive link 52. This rests on the deadbolt 13, pillar 28, the higher part of rib 27 and rod connector 42 and is pivotally received over the post 29 on the pillar 28. At its upper end it has an elongated slot 53 which receives the guide pin 41.

At its side facing the plate 18 there is an elongated slot 54 extending at an angle into the link, the slot having parallel straight sides 55, 56 with an arcuate closed interior end. Received in the slot 54 is the guide pin 44.

The secondary unit thus provides additional security by providing both a laterally movable deadbolt as well as a longitudinally movable deadbolt, both actuated simultaneously by the rod connected to the primary unit of the locking mechanism.

Thus if, with the door locked, an intended intruder inserted a tool into the gap between the edge of the door and its adjacent jamb, any tendency for the lateral deadbolts 13 to be forced out of their respective keepers at the jamb and the door thus to open, would be resisted by the upper and lower vertical bolts 51 engaged in their respective associated upper and lower keepers. Consequently the extra security of the vertical bolts could allow a reduction in the amount by which the deadbolts of the primary and secondary units are shot in their engaged positions, enabling shorter deadbolts to be used.

Thus, in use, the bolt 51 and deadbolt 13 will both be in the withdrawn or retracted state when the upper rod is retracted towards the primary unit. In this position the flange 49 lies just above the top of plate 17, the pin 41 is at the end of the slots 21, 22 nearest the rear plate 18 and the pin 44 is at the bottom of the slots 19, 20, and at the arcuate end of the slot 54. If the upper rod is now extended upwardly, the guide pin 44 engages against the angled side 55 of the slot 54, and the force applied to this side causes the drive link 52 to pivot anticlockwise, as viewed in Figure 2, as the pin 44 moves up the slots 19 and 20. The pivotal movement of the drive link 52 is transmitted to the guide pin 41 by a side of the slot 53, which side is at an angle to the vertical in this position of the drive link.The angled side of the slot thus pushes the pin 41 sidewardly, with the result that the deadbolt is extended, the movement of the pin 41 also pivotting the link 37 against the bias of the spring 34. To assist in the pivotting of the link 52 by the pin 44, the side 55 of the slot 54 can have a short arcuate shoulder against which the pin 44 can positively push until pivotting of the drive link has been established.

As the connector 42 slides upwardly, it causes the plate 46 connected to it also to slide upwardly and thus to extend the bolt 51 into its keeper when the door is in a closed state. The deadbolt 13 similarly extends into a keeper in a facing door jamb, the spring 34 biasing the deadbolt to its extended position.

Figure 2 shows the extended positions of the bolts.

When the rod 11 is retracted, the pin 44 engages the surface 56 of slot 54 to pivot the drive link 52 clockwise, thus withdrawing the deadbolt by pivotting the link 37 anticlockwise against the spring 34.

Downwards movement of the connector 42 pulls the plate 46 and bolt 51 downwards also.

Although described for an upper secondary unit, an identical unit 10 can be used as a lower secondary unit simply by inverting it. The rod 11 then becomes the lower connection rod to the primary unit of the locking mechanism.

For increased strength and thus improved security, the outer surface at the 90" junction of the flange 49 and plate 46 can be reinforced by providing an inwards displacement of metal leaving a longitudinal groove on the outer surfaces of flange 49 and plate 46 and a corresponding projection of the inner surfaces thereof.

Figure 4 shows a bracket 57 having a base 58 from which extends at 900, a pair of spaced, parallel arms 59.

The base is intended to be secured by holes 60 to the inner surface of the faceplate 12 so that the bolt 51 moves, in use, through respective aligned holes in the arms 59 and is thus guided. Without these guides, it is possible the bolt could rock off-vertical and misalign with its keeper. Thus the bracket 57 would also be provided with the unit of Figures 1 to 3.

The bolt 51 could be supplied with longitudinally spaced, shaped weakened sections to allow it to be cut to length whilst still providing a pointed end for engagement in its keeper.

Instead of the arrangement of bolts shown, alternative types of bolts could be substituted. For example a hook bolt could be used instead of the bolt 13.

Although it would move pivotally, this would still effectively be at 900 to bolt 51 when both were extended.

Claims (16)

1. A secondary unit for a locking mechanism having a primary unit, the secondary unit comprising means for operatively connecting it to the primary unit, and first and second bolts which are extendable or retractable, in use, by actuation of said connecting means from the primary unit, the extended position of the first bolt being at right angles or substantially at right angles to the extended position of the second bolt.

2. A unit as claimed in claim 1, wherein the bolts move simultaneously or substantially simultaneously on actuation of said connection means.

3. A unit as claimed in Claim 1 or Claim 2, comprising a casing having a front face and an end face which are mutually perpendicular, the first and second bolts extending out of and retracting into said front and end faces respectively, in use, in respective directions normal thereto.

4. A unit as claimed in Claim 3, wherein the connecting means is a connector which is adapted to be connected, in use, to a rod or bar extending from the primary unit, the connector being secured to a plate slidably disposed in the casing, and carrying said second bolt, so that sliding movement of said rod or bar is transmitted to the connector, to said plate and thus to the second bolt.

5. A unit as claimed in Claim 4, wherein the connector is adapted to be pivotally connected to said rod or bar.

6. A unit as claimed in Claim 4 or Claim 5, wherein the movement, in use, of the connector is guided by an internal rib of the casing and is limited by engagement of a pin carried by the connector with the ends of a slot in one or both of two opposite side faces of the casing.

7. A unit as claimed in any one of Claims 4 to 6, wherein the sliding of the plate, in use, is guided between a rear face of the casing and at least one lug extending from an internal surface of the casing.

8. A unit as claimed in any one of Claims 4 to 7, wherein said second bolt is a cylindrical rod having an end threadedly engaged in a spigot on a cranked end of said plate.

9. A unit as claimed in Claim 6, wherein the pin is received in an elongated slot in a drive link pivotally mounted in the casing, the drive link having a further elongated slot therein which receives a further pin carried by the first bolt, movement of the connector, in use, as a result of movement of said rod or bar, causing said pin to pivot said drive link and retract or extend said first bolt.

lO. A unit as claimed in Claim 9, wherein said further pin or another pin is received in an elongated slot in a retaining link at one side of said first bolt, the retaining link being pivotally mounted in the casing and being biased to retain the first bolt in its fully extended and fully retracted positions.

11. A unit as claimed in Claim 10, wherein the retaining link is biased by a blade spring, respective different matchingisurfaces of the spring and the retaining link engaging, in use, in said fully extended and fully retracted positions of the first bolt.

12. A unit as claimed in any one of the preceding claims, wherein said first bolt has a rectangular dead bolt part which extends, in use, the first bolt extending and retracting along raised strips.

13. A unit as claimed in Claim 12, comprising a casing having a rear face, and wherein the strips terminate short of said rear face in respective upstanding lugs, a slidable plate being guided between the lugs and said rear face and transmitting sliding movement, in use, from a rod or bar extending from the primary unit to said second bolt.

14. A unit as claimed in any one of Claims 3 to 8, wherein said sliding of second bolt, in use, is guided by a bracket outside of the casing.

15. A locking mechansim comprising a primary unit and at least one secondary unit as claimed in any one of Claims 1 to 14 operatively connected thereto.

16. A secondary unit substantially as hereinbefore described, with reference to, and as shown in Figures 1 to 3 or Figures 1 to 3 as modified by Figure 4, of the accompanying drawings.