GB2287751A

GB2287751A - Door lock mechanism

Info

Publication number: GB2287751A
Application number: GB9505899A
Authority: GB
Inventors: Edward William Henderson
Original assignee: Individual
Current assignee: Individual
Priority date: 1994-03-23
Filing date: 1995-03-23
Publication date: 1995-09-27
Anticipated expiration: 2015-03-23
Also published as: GB2287751B; GB9505899D0; GB9405759D0

Abstract

The present invention relates to a door lock mechanism 1 having internal 4 and external 6 rotary handles and an external locking means 24. The handles are connected via a shaft 8 which carries a cam means 10 having a portion 10b which, on cam rotation, drives bolt member(s) 14 outwardly, against basing means 12, from a first retracted, unlocked, position towards a second extended, engaged, position. The cam means 10 can also be axially displaced in direction C by the internal handle 4, so as to disengage the bolt member(s) 14 from the portion 10b (as shown in fig 2) and allow bolt return to the unlocked position under the influence of the basing means 12. The internal handle 4 has internal locking means 16 to lock the handles against rotation. <IMAGE>

Description

DOOR LOCK MECHANISM The present invention relates to a door lock mechanism for use on domestic main doors but not exclusively.

Door lock mechanisms of various types including espagnolette and cremorne bolt type fastenings have been previously proposed and generally comprise an internal handle means, an external handle means and a locking mechanism to secure a door in a locked position. In order to be able to open such a door lock mechanism, from either the inside or the outside, it is necessary first to unlock the door lock, usually with a key, and then operate the handle to open the door. It will be appreciated that whilst such conventional door lock mechanisms and arrangements provide a good degree of security they do not facilitate the rapid unlocking and opening of a door and exit therethrough that is required in the event of an emergency such as a fire.Panic bar devices for use in industrial and commercial applications where doors must open outwards in compliance with the various building and health and safety regulations are also generally well known, such mechanisms though are only operable from the inside (not from the outside for security reasons) and thus are completely unsuitable for domestic applications such as front and back doors which require to be operable from both sides in normal use.

It is an object of the present invention to avoid or minimise one or more of the above disadvantages.

The present invention provides a door lock mechanism having internal and external handles, formed and arranged for rotary movement and an external locking means for external locking of said door lock mechanism, said external handle being connected to said internal handle via a shaft provided with cam means, said cam means being formed and arranged for driving at least one bolt member from a first retracted, unlocked, position in engagement with an unlocking portion of said cam means towards a second extended, engaged, position in engagement with a locking portion of said cam means, characterised in that said at least one bolt member has return biasing means for retaining an end portion of a said at least one bolt member in abutment with said cam means and said cam means being formed and arranged to be axially displacable with said internal handle, so as to disengage said at least one return biased bolt member from said locking portion of said cam means and allow it to return to said first retracted, unlocked, position under the influence of said return biasing means; said internal handle having internal locking means formed and arranged for locking of said door lock mechanism by locking said handles against rotation, whereby, in use, said door lock mechanism may be unlocked by axially displacing the interior handle.

Thus with a door lock mechanism according to the present invention a door fitted therewith may be readily and simply secured against unwanted opening from the outside whilst permitting, in the event of an emergency, the rapid unlocking and opening of the door from the inside in a simple, quick and efficient manner without the need for a key by simply pushing or pulling of the internal door handle - depending on whether the door is inwardly or outwardly opening.

Preferably for an inwardly opening door in use of the door lock mechanism of the present invention said internal handle and said cam means are formed and arranged to be axially displacable inwardly by pulling on said internal handle, whilst for an outwardly opening door said internal hand and said cam means are desirably formed and arranged to be axially displacable outwardly by pushing on said internal handle.

Preferably there are provided two bolt members, a first top bolt member formed and arranged for extending vertically upwardly from said cam means inside a door in use of the invention and extending outwardly of the top of said door when in said extended engaged, position; and a second bottom bolt member formed and arranged for extending vertically downwardly from said cam means inside said door and extending outwardly of the bottom of said door when in said extended engaged position. Desirably a door frame assembly in use of the door lock mechanism according to the invention is provided with apertures therein to receive an end portion of said bolt member when in said extended engaged position.

Additionally there may be provided on at least one bolt member a linkage means formed and arranged for extending a second bolt member outwardly of the side of a door in use of said door lock mechanism thereby to provide a further degree of security.

In another respect the present invention provides a door and door frame assembly, said door having a door lock mechanism of the invention and said door frame having recess means formed and arranged for receiving extended end portions of bolt members in said extended engaged position for locking said door into said door frame assembly.

In normal use of the door lock mechanism according to the invention preferably said internal and external handles and said cam means are formed and arranged to be rotatable by turning one or other of said handles through around ninety degrees (900) to release the door lock mechanism in a manner generally similar to conventional door handles.

Preferably said external locking means is of generally well known barrel and key type, and is formed and arranged to lock the door lock mechanism so that said external handle is fixed in a locked position and cannot be rotated to release a said at least one bolt member via said cam means.

Preferably said internal locking means is in the form of an axially displacable locking pin for internal locking of said mechanism and simultaneously locking the external handle in a fixed locked position. Preferably said locking pin when in a locking position also prevents a door in use of the door-lock mechanism being opened by turning of the internal handle, whilst still permitting, in an emergency, unlocking thereof by axial displacement of the interior handle.

Alternatively said internal locking means is of generally well known barrel and key type and where both said internal and external locking means are of said barrel and key type there may be used a single, double ended cylinder type lock such as that supplied by the Union Company of England.

Preferably once said door lock mechanism has been deliberately or accidentally operated for such emergency opening, said cam means and said at least one bolt member are formed and arranged to permit return of said at least one bolt member into abutment with said cam means simply by axially displacing said interior handle and said cam means in a direction opposite to that to unlock the interior handle. Alternatively though re-engagement of the cam means could be arranged to be effected by rotation of one or other of the handles, after unlocking thereof, to its open position and subsequent reverse axial displacement of the internal handle.

Preferably there is provided on said door lock mechanism indicator means formed and arranged to indicate to users that the door lock mechanism is in a locked and primed condition.

Further preferred features and advantages of the present invention will appear from the following detailed description given by way of example of a preferred embodiment illustrated with reference to the accompanying drawings in which:-Fig. 1 shows a cut-away side elevation of a door lock mechanism according to the invention; Figs. 2 and 3 show side and end elevations respectively of a cam means of the door lock mechanism of Fig. 1; Fig. 4 shows a side view of a side bolt assembly for use with the door lock mechanism of Fig.1; and Fig. 5 is an end evaluation of the cam means of Fig. 3 with a lever driven bolt member.

In more detail, Fig. 1 shows a door lock mechanism generally indicated by reference number 1, fitted to a door 2 in a door frame 3. The door lock mechanism comprises an internal handle 4 connected to one external handle 6 via a shaft 8 and a cam 10. (see also Figs. 2 and 3). Two spring 12a, b loaded elongate bolt members 14 are provided, one 14a passing vertically up through the door 2, and the second 14b passing vertically down through the door 2. As shown the bolts 14a, b are in an extended position in engagement with recesses 15a, b, respectively, on the bottom 3a and top 3b of the door frame 3, thereby locking the door 2 in the door frame 3.An internal axially displacable locking pin 16 is provided, which may be screwably (not shown) or slidably inserted through an axial aperture 18 in the internal handle 4 and through into engagement with the door lock mechanism body 20. The arrangement of the pin 16 in the internal handle 4 and the mechanism body 20 prevents either of the handles 4, 6 from being rotated so as to open the door.

Externally there is provided a key 22 operable lock 24 to lock the external handle 6 in a fixed locked position (as shown).

In normal use the locking pin 16 may be retracted out of the lock body 20 so that the internal handle 4 or the external handle 6 may be rotated to open the door. As the cam 10, which has an oval profile having an upper profile lOb and lower profile 10a (see Fig. 3), is rotated by either one of the door handles 4, 6, the bolt members 14 follow via cam followers 26a, b the profile of the cam 10 and are driven back to a retracted unlocked position (not shown) by respective return springs 12a, b acting between the lock body 20 and the cam 10. To close the door and extend the bolt members 14 into the extended engaged position either of the handles may be operated in a direction opposite to that to open the door thereby to turn the cam 10 (arrow A Fig. 3) and drive the bolt members 14 into engagement with the recesses in the door frame.To lock the door from the outside the key 22 operated lock 24 once operated engages with the external handle 6 to prevent it being rotated. It will be appreciated that as the internal handle 4 is axially connected to the external handle 6, the internal handle 4 cannot be rotated either if the external handle 6 is locked.

In the event of an emergency and/or there being someone in a house having a door with a locked door lock mechanism according to the present invention, the internal handle 4 may be pulled outwardly (shown by Arrow B) to open and unlock the door irrespectively of whether the internal 4 or external 6 handles is prevented from rotational movement by the respective locking pin 16, or the key operable lock 24.

As the internal handle 4 is pulled inwardly the cam 10 is pulled also (shown by arrow C in Fig. 2) to the side 30 of the door lock mechanism body 20 and thus disengages with the bolt members which are driven by the action of the return springs into the retracted unlocked position 31 (see Fig. 2) thereby unlocking the door. It will be understood that the pulling action on the handle also serves to pull open the door thus making the unlocking and opening of the door a single operation. It will be appreciated this is a particularly desirable feature in the event of an emergency e.g. a fire.

In order to return the door lock mechanism back to conventional operation, either of the handles are rotated to the open position thereby turning the cam 10 through 900 to that shown in Fig. 3 and the internal handle 4 pushed inwardly so that the cam followers slide into engagement on the lower 10a profiled portion of the cam 10.

Various modifications may be made to the above described embodiment without departing from the scope of the present invention. Thus for example and as shown in Fig. 4 there may be provided on at least one of the elongate bolt members 14 a side bolt assembly 32 comprising a linkage mechanism 33 comprising and having a first end 34 connected to the elongate bolt member 14 and a second end 36 connected to a side bolt member 38. As the elongate bolt member 14 moves up and/or down the linkage mechanism 33 pivoting about a point 40 transfers the vertical movement 'D' of the elongate bolt member 14 into horizontal movement 'F' of the side bolt member 38 so as to drive the side bolt in or out of the door. The side bolt member 38 in its extended position (shown) is arranged to engage with a recess (not shown) in the side of the door frame. With the side bolt member in its retracted position the linkage mechanism 33 is shown in broken chain line.

In the event that one of the springs 12 of the spring loaded elongate bolt members should break there may be provided as shown in Fig. 5, a lever 42 driven bolt member 14 so that the bolt members may be disengaged. The right angled lever 42 pivoting about a point 44 has a first end 46 which follows the profile of the cam 10 and the second end 48 is connected via a pin 50 to a housing 52 which contains the spring (not shown).

Claims

1. A door lock mechanism having internal and external handles, formed and arranged for rotary movement and an external locking means for external locking of said door lock mechanism, said external handle being connected to said internal handle via a shaft provided with cam means, said cam means being formed and arranged for driving at least one bolt member from a first retracted, unlocked, position in engagement with an unlocking portion of said cam means towards a second extended, engaged, position in engagement with a locking portion of said cam means, characterised in that said at least one bolt member has return biasing means for retaining an end portion of a said at least one bolt member in abutment with said cam means and said cam means being formed and arranged to be axially displacable with said internal handle, so as to disengage said at least one return biased bolt member from said locking portion of said cam means and allow it to return to said first retracted, unlocked, position under the influence of said return biasing means; said internal handle having internal locking means formed and arranged for locking of said door lock mechanism by locking said handles against rotation, whereby, in use, said door lock mechanism may be unlocked by axially displacing the interior handle.

2. A door lock mechanism according to claim 1 wherein in use for a inwardly opening door said internal handle and said cam means are formed arranged to be axially displacable inwardly by pulling on said internal handle.

3. A door lock mechanism according to claim 1 where in use for an outwardly opening door said internal handle and said cam means are formed and arranged to be axially displacable outwardly by pushing on said internal handle.

4. A door lock mechanism according to any one of claims 1 to 3 wherein there are provided two bolt members, a first top bolt member formed and arranged for extending vertically upwardly from said cam means inside a door in use of the invention and extending outwardly of the top of said door when in said extended engaged, position; and a second bottom bolt member formed and arranged for extending vertically downwardly from said cam means inside said door and extending outwardly of the bottom of said door when in said extended engaged position.

5. A door lock mechanism according to any one of claims 1 to 3 wherein said at least one bolt member is formed and arranged to extend via a linkage means a second bolt member outwardly of the side of a door in use of said door lock mechanism.

6. A door lock mechanism according to any one of claims 1 to 5 wherein said external locking means is a barrel and key type lock formed and arranged to lock the door lock mechanism whereby said external handle is fixed in a locked position and cannot be rotated to release a said at least one bolt member via said cam means.

7. A door lock mechanism according to any one of claims 1 to 6 wherein said internal locking means is in the form of an axially displacable locking pin for internal locking of said door lock mechanism and simultaneous locking of said external handle in a fixed locked position.

8. A door lock mechanism according to claim 7 wherein said pin is formed and arranged for locking said internal handle in a fixed locked position whilst still permitting axial displacement of said interior handle.

9. A door lock mechanism according to any one of claims 1 to 6 wherein said internal locking means is a barrel and key type lock and is formed and arranged for locking said internal handle in a fixed locked position whilst still permitting axial displacement of said interior handle.

10. A door lock mechanism according to any one of claims 1 to 9 wherein there is provided on said door lock mechanism indicator means formed and arranged to indicate to a user thereof that the door lock mechanism is in a locked and primed condition.

11. A door and door frame assembly, said door having a door lock mechanism according to claim 1 and said door frame having recess means formed and arranged for receiving extended end portions of bolt members in said extended engaged position for locking said door into said door frame assembly.

12. A door lock mechanism substantially as described hereinbefore and with reference to Figs. 1 to 3 of the accompanying drawings.