GB2414509A

GB2414509A - Door lock with key-releasable ecurity chain

Info

Publication number: GB2414509A
Application number: GB0414818A
Authority: GB
Inventors: Stuart Rennie
Original assignee: Individual
Current assignee: Individual
Priority date: 2004-05-24
Filing date: 2004-07-02
Publication date: 2005-11-30
Also published as: GB0414818D0

Abstract

A door lock mechanism has sliding bolt which is retractable by means of an external key-operated lock K and has a security chain with an end portion I engaging into the lock casing and retained by a pivoting member D. When the lock K is operated to retract the bolt a formation F engages member D to simultaneously release the security chain. A thumb slide P can be used to disengage member D from the inside of the door. The end portion I shown has a round section but an embodiment with a flat end portion is also disclosed.

Description

241 4509

Description

Baclround This is a domestic 5 lever night-latch (Rim-Cylinder) door lock fitted to a door with a chain sliding bolt which is attached to the door frame strike and, when in use, extends to, and is secured to the lock by sliding upwards into the lock case on the inside of the door. In the event of an emergency, where the occupant is unable to get to the door, the chain sliding bolt (inside) can be gravity released from the door lock by use of a key from the outside. A door handle is fitted to the lock inside the house and below the handle there is a bolt thumb release switch which would release the chain sliding bolt from inside. The lock could be used in a 'Dead-Lock' mode from outside by a key, or from inside by raising the door handle.

This lock could be produced for Left Hand or Right Hand fitted doors by adapting the design to suit each type.

Advantages I'his invention means that anyone who has put the chain bolt into the lock on the inside of a house, and subsequently becomes ill and is unable to get to the doors, could be released by someone outside who has a key t'or the house.

i.e. Neighbour, Elderly peoples wardens, relatives.

Alternatively, anyone inside who wishes to secure the premises for the night could put the chain on and retire' however when the last occupant arrives home they could release the chain and allow themselves in before replacing the chain in the lock.

Additionally, this sliding bolt could easily be gravity released rather than slide bolts horizontally across the door before releasing the bolt.

Example

An example of the invention will now be described by referring to the accompanying drawings.

Drawine Numbers: L)wg No 1/9 Door Lock with strike and chain fitted to door frame Dwg No 2/9 Exploded View of Lock showing round bolt (less 5 lever lock parts) Dwg No 3/9 Exploded View of Lock showing flat steel bar (Option to Dwg No 2 above) Dwg No 4/9 Front (inside) and Side Views (I, ess Inner Mechanism E) Dwg No 5/9 Front (inside) and Side Views with alternative spring (Ha) L)wg No 6/9 Bolt Inserted / Bolt Released when Bawl rotates and applies pressure to Chain Bolt Catch Dwg No 7/9 Close t) p of Bolt Release Bawl (F) / Chain Bolt Catch (D) with Spring (}la) / Sliding Bolt Thumb Release (P) Dwg No 8/9 Inside view of lock cover showing handle held with circlip and chain bolt thumb release.

Owg No 9/9 C'ylinder(K) /Mounting plate (Aa) / Chain Lock Case(A) and Cover (C) showing side and plan views Index to Letters on DrawinEs: A Chain Lock case which screws onto mounting plate.

Aa Mounting plate for door B Solid steel base with bolt release hole (M) drilled through it.

C Lock case cover ( covers all body and screws onto chain lock case from the side or the base) D Chain round bolt catch (or flat metal bolt catch) F. I,ock inner mechanism (Not shown) F Bolt release Pawl C] Lock door handle H Rod bolt catch spring I la Alternative rod bolt catch spring I Round chain bolt la lariat chain bolt J Chain connected to door frame strike K Key cylinder L Holes for screws to secure lock frame to mounting plate M Hole for sliding bolt (Slightly Recessed) N Rod for D and H O Lock cylinder net rod P Sliding bolt thumb release Dcsian The lock would be a night-latch design domestic door lock with a key but adapted in the following maimer.

Please refer to drawings No I to 9.

The lock cylinder ( K) would fit into the door from the front and be secured by two screws fitted from inside and through a mounting plate (Aa) . The mounting plate would be screwed to the inside of the door. The lock case (A) would then be screwed in place onto the mounting plate via holes (1,). Alternatively, the cylinder could be screwed onto a holding plate which is screwed directly onto the door.

The inside ofthe lock case would have the following additions: The lock base (B) would be a significant thick steel with a slightly recessed hole (M) drilled through it from the bottom into the lock case. The chain bolt ( I), of a slightly smaller diameter than the hole, and with a recess cut into it around its circumference rim near the top, would slide upwards into the case from below the hole.

Inside the lock case, a clip (D), which is spring controlled, would fit into the rim recess holding the bolt (1) in place when inside the hole (M) .

The clip would have a hole in it, and this hole would be mounted on a rod (N) extending from the lock case(A) from above the thick steel (B).

The lock cylinder would have a flat rod (O) extending prom it into the lock mechanism. Inside the lock case, the flat rod would normally connect into the lock mechanism (E), opening the door when the key is used, however at this point the operating mechanisms are altered as follows. Inside the lock mechanism, the flat rod would enter it, but would penetrate a Bawl (17) bet'ore continuing through the lock mechanism.

The bolt release Bawl fixed onto the flat rod inside the locking mechanism would be turned in the direction the key is turned in the barrel to unlock the door. If the bolt was fitted into the lock, then the pawl would strike the clip (1)) thus releasing the bolt.

When the key was turned opposite to the direction required to open the door, the Pawl would turn freely on the Lock Cylinder Flat Rod (O) and the locking bolt would be forced 'home' as a aead-lock.

The lock case would have a metal cover which fits over it, and this would be secured by screws which penetrate the body via holes in the cover on the door-frame side or upwards from the base.

Considerations I 'I'he lock could be produced for left hand and right hand door handle finings.

2 The solid steel base could be adapted to be solid around the bolt hole area only to save steel and cost.

3 'I'he bolt could be a flat steel bar which slides in through a rectangular hole rather than a round bolt hole.

4 'I'he bolt (or rectangular) hole should be slightly recessed at the bottom to allow ease of access for the sliding bolt / bar. (See Drgs No 4 / 5 and 6) 'I'he sliding bolt (Flat steel bar) could be held in place by a chain bolt catch (See Drg No 3) 6 'I'he sliding bolt thumb release (P) could be operated by two different methods of 'spring' control.

a) Spring (H) fitted onto the Rod (N) (Drgs No 2 /3 14) b) Spring (Ha) fitted onto chain bolt catch (D) and held onto the lock case. (See Drgs No 5 / 6) t

Claims

Claims I claim: I A door lock comprising: a domestic 5 lever night-latch

(Rim-Cylinder) lock, (or 3/4/6/7 lever night-latch lock) fitted to a door with a key cylinder attached to it through the door, with the barrel secured to a mounting plate with screws from inside the door, and with the case of the lever night-latch screwed to the mounting plate, and with a metal cover which encases the case of the lock and is screwed onto it..

2 a door lock according to claim 1, where a lock strike is screwed onto the door frame, parallel with the 5 lever night latch so that the lock fits home into the strike when the door is closed.

3 a door lock according to claim 2, where the lock can be opened from outside by a key, and from inside by turning the door handle.

4 a door lock according to claim 3, where the lock strike is screwed to the frame of the door and a chain hangs from the lock strike below it, with a sliding bolt attached to the end of the chain, this said sliding bolt having a rim cut into its circumference at the end furthest away from the chain.

a door lock according to claim 4, where the lock is designed and modified to allow the sliding bolt to enter a recessed hole in the base of the lock, and which is slightly wider in diameter to the sliding bolt and, when in place the sliding bolt remains inside the lock by the rim being held by a Chain Bolt Catch.

6 a door lock according to claim 5, where a secure round sliding bolt (of a slightly smaller diameter than the recessed round hole) with a groove cut into its rim near the top, could be inserted through the recessed round hole in the base of the lock cover and this sliding bolt would penetrate the hole, and the rim would click into place by fitting into the bolt retaining rod on the Chain Bolt Catch.

7 a door lock according to claim 6, where the base of the lock metal case is thick and strong to prevent leverage of the bolt weakening the base and releasing the sliding bolt when the door is forced.

8 a door lock according to claim 7, where the base of the metal cover has a slightly recessed round hole penetrating upwards into the case and this recess allows the sliding bolt to easily slide upwards into the case of the lock.

9 a door lock according to claim 8, where the cylinder lock rod penetrates a 'Pawl' (inside or outside the case working mechanism) prior to operating the conventional five lever night latch, so that when the key is used to open the door, the lock rod rotates in the direction of the said key causing the pawl to rotate in the same direction until it strikes the Chain Bolt Catch, causing it to rotate and gravity release the sliding bolt when in use.

a door lock according to claim 9, where when the Pawl is turned away from the direction required to release the bolt, it would turn the kick bolt making it a 'Dead-Lock', however when the key was turned in the opposite direction, then this would cause the Pawl to rotate until it strikes the Chain Bolt Catch, causing it to rotate and gravity release the sliding bolt when in use.

11 a door lock according to claim 10, where a thumb release on the outside ofthe lock cover, and just below the door handle, (or on the side or top if suitably adapted) would allow the secure sliding bolt to gravity drop out of the lock when slid sideways against the Chain Bolt Catch from inside the door.

12 a door lock according to claim 11, where, in the event that someone is inside the house who is unable to get to the door, then the sliding bolt (if in use) can be released from outside by turning the key.

13 a door lock according to claim 12, where the case of the lock is covered by a metal cover which fits over it, however the said cover has a hole in the base to allow the said sliding bolt to penetrate it into the lock case, this said cover being secured to the lock case either by screws from the door-frame side or upwards from the base.

14 a door lock according to claim 13, where the round sliding bolt is designed and replaced by a flat metal rod which slides upwards into a rectangular (recessed) hole, slightly wider than the flat metal rod, and which operates in a similar manner to previous claims.

a door lock according to claim 14, where the lock cylinder is screwed through a holding plate on the inside of the door, where the lock case is screwed directly onto the inside part of the door and covering the cylinder holding plate, thus dispensing with the mounting plate.

16 a door lock according to claim 15, where the inside lock handle could be lifted upwards causing the strike bolt to enter the 'Dead-Lock mode.

17 a door lock according to claim 16, where the sliding bolt is not released from outside, there is no Pawl to operate the Chain Bolt Catch, and where the sliding bolt is released by the thumb release from inside only, this being only a design modification.