GB2369856A

GB2369856A - Anchor member for a mortice lock and a mortice lining

Info

Publication number: GB2369856A
Application number: GB0029605A
Authority: GB
Inventors: John Window
Original assignee: Florin Investments Ltd
Current assignee: Florin Investments Ltd
Priority date: 2000-12-05
Filing date: 2000-12-05
Publication date: 2002-06-12
Also published as: GB0029605D0

Abstract

A mortice lock 1 for a door 2, comprises a housing 10 with an anchor member 14. The anchor extends from the housing in a plane parallel to the faces of the door and has a width B which is less than the width A of the housing. The anchor is received in a recess, e.g bore [6, fig. 1], of a mortice [4, fig. 1]. The anchor may be in the form of a pin or a plate and more than one anchor may extend from the housing. A mortice lining is also disclosed and may comprise three separate U-shaped channels [23,26, fig 6] or a metal sleeve [30, fig. 8]. In each case one or more anchors, e.g. pin and plates [24,28 fig 6], are provided. The anchors strengthen the mortice against excessive forces applied to either face of the door.

Description

TITLE Improved Mortise Lock and Mortise Lining DESCRIPTION Field of the Invention The invention relates generally to a mortise lock for installation within a side edge of a door to secure the door in a locked condition with respect to a frame surrounding the door. In particular, the present invention seeks to improve the strength of such a lock so that when it is installed in a door it is capable of withstanding greater forces applied to a front or rear surface of the door.

Background Art The housings of conventional mortise locks are generally rectangular in shape for installation within similarly shaped mortises machined from vertical side edges of doors. Such a housing contains locking members which may be actuated by a key or handle to extend a bolt or latch from the housing across a gap between the side edge of the door and the surrounding frame, and into a corresponding keeper on the frame. Thereby the door is secured to the frame.

The mortise machined in the vertical side edge of the door is defined by a rear wall remote from the side edge of the door, two opposing vertical sidewalls and two opposing horizontal walls. Accordingly, any pressure applied to a front or a rear surface of the door while the lock is in the secured condition is transferred through the two opposing vertical sidewalls of the mortise, through the lock, through the bolt and into the keeper of the frame. Normally, doors are not very wide and a typical door may be 35mm wide. If a typical lock is to be installed within such a door, a mortise having a width of approximately 23mm must be machined from the door to house the lock. Accordingly, each of the vertical sidewalls of the mortise is only 6mm thick and they are capable of transferring only a limited amount of force from the front or rear surface of

the door to the lock. If the force exceeds an upper threshold, one or both of the vertical sidewalls of the mortise will fracture and the lock will give.

Obviously, the upper threshold can be increased by increasing the thickness of the door or by reducing the width of the lock. However, both doors and locks are generally manufactured in standard sizes and accordingly nonstandard doors or locks are significantly more expensive than those factory standards.

Accordingly, it is an objective of the present invention to enhance the strength of a lock installed within a mortise in a conventional door so that it is capable of withstanding greater forces exerted on the front or rear surfaces of the door, neither the housing of the lock nor the side edge of the door having substantially modified widths.

Summary of the Invention In accordance with the objective outlined above, the present invention provides a mortise lock for installation into a mortise formed in a side edge of a door having a front and a rear surface. The lock comprises a housing containing locking elements and an anchor member extending from an edge surface of the housing. The anchor member has a width which is less than that of the housing such that when the lock is installed in the mortise the anchor member extends from the mortise into a recess formed in a solid portion of the door in a plane substantially parallel to the front and rear surfaces of the door.

In this arrangement, the or each anchor member effectively increases the surface area of each of those walls positioned between the housing together with the anchor member and the front and rear surfaces of the door respectively and thereby any force exerted on the front or rear surface of the door is transferred across a greater surface area and hence the lock is capable of withstanding greater forces. Furthermore, as the anchor member is

thin relative to the housing, not only is the surface area of the walls positioned between the housing together with the anchor member and the front and rear surfaces of the door increased, but their effective thickness is also increased.

Naturally, the lock could be further improved if more than one anchor member is provided thereon, each being received in a respective recess.

Preferably, the lock is provided with three anchor members. The first anchor member extends form a rear surface edge of the housing and the other two anchor members extend from edges surfaces of the housing that are mutually perpendicular to the rear edge surface. Preferably, the first anchor member is a steel pin that is received in a hole formed in a solid portion of the door and the other two anchor members are steel plates, each of which is received in a respective slot formed in a solid portion of the door.

The present invention also provides a lining for a mortise formed in a side edge of a door having a front and a rear surface, the lining partially or completely receiving a housing of a lock. The lining comprises an engagement means to engage with the housing of the lock and an anchor member extending from the engagement means having a width which is less than that of the housing of the lock. Accordingly, when the lining and the lock are installed in the mortise, the anchor member extends from the mortise into a recess formed in a solid portion of the door in a plane substantially parallel to the front and rear surfaces of the door.

Preferably, the engagement means is a U-shaped channel having a central crosspiece and two legs extending therefrom in a direction which is substantially perpendicular to the crosspiece to engage with the housing of the lock, and the anchor member extends from the central crosspiece of the engagement means in a direction opposite to that of the legs.

Alternatively, the engagement means could be a sleeve having an open end into which the lock is inserted. In this arrangement, the sleeve is preferably provided with three anchor members. The first anchor member extends from a rear edge surface of the lining which opposes the open end of the lining and the other two anchor members extend from edge surfaces of the lining that are mutually perpendicular to the rear edge surface.

Brief Description of the Drawings By way of example only, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings in which: Figure 1 is a partial plan view of a solid door secured to a surrounding frame by a lock according to a first embodiment of the invention; Figure 2 is a perspective view of the lock illustrated in Fig. 1; Figure 3 is a plan view of the side edge of the door shown in Fig. 1 with the lock removed; Figure 4 is a partial plan view of a cavity door fitted with the lock illustrated in Fig. 2; Figure 5 is a perspective view of a lock according to a second embodiment of the present invention; Figure 6 is a perspective view of a plurality if mortise linings according to a third embodiment of the invention; Figure 7 is a plan view of a side edge of a door into which the mortise linings of Fig. 6 are inserted; and Figure 8 is a perspective view of a mortise lining according to a fourth embodiment of the invention.

Detailed Description of the Preferred Embodiments A first embodiment of a lock 1 according to the present invention is shown in Figs. 1 to 3. The lock 1 is installed within a side edge 2a of a solid door 2 having a front surface 3a and a rear surface 3b (shown in Fig. 3). The lock 1, in conjunction with hinges (not shown) provided on an opposing side edge of

the door 2, releasably secures the door 2 to a frame 7 mounted in a wall 5 or other structural member.

As shown specifically in Fig. 2, the lock 1 comprises a metal housing 10 which is provided with a forend plate 12 that lies flush with the side edge 2a of the door 2 when the lock 1 is installed therein and a steel rod or pin 14 extending from an edge surface of the housing 10 which is remote from the forend plate 12. The steel pin 14 acts as an anchor member. The housing 10 is of a conventional width A. The steel pin 14 has a diameter B. Diameter B is substantially less than width A.

A receiver hole 15 is formed in the housing 10 to receive a pivot shaft 19 of a handle 20 mounted on the front surface 3 of the door 2. Counter-clockwise rotation of the handle 20 from the position to which it is biased as shown in Fig. 1 causes a latch 16 which extends from the lock 1 through the forend plate 12 and into a latch keeper 8 formed in the frame 7 to become substantially withdrawn into the lock 1 enabling the door 2 to be opened.

Although not shown, the receiver hole 15 could be a through hole such that the pivot shaft 19 communicates the movement of the handle 20 on the front surface 3a of the door 2 to a corresponding handle mounted on the rear surface 3b of the door 2.

In a similar manner, a key hole 17 is formed in the housing 10 to receive a corresponding key (not shown) to activate a dead bolt 18 that slides along an axis represented as C in Fig. 2 into and out of a bolt keeper 9 in the frame 7 to securely lock and unlock the door 2 to and from the frame 7.

As shown in Fig. 3, to install the lock 1 within the door 2, the initial step is to machine out the respective recesses necessary to accommodate the lock 1 in the side edge 2a of the door 2. These include a principal mortise 4 to accommodate the housing 10 of the lock 1, a cylindrical bore 6 extending

backwards from the principal mortise 4 to house the steel pin 14 and a stepped recess 4a surrounding the principle mortise 4 for the forend plate 12.

Furthermore, communication holes 21 are machined through from the front surface 3a of the door 2 to the principal mortise 4 of the door 2 for the pivot shaft 19 and to enable a user to insert a key into the key hole 17 of the lock 1, respectively.

The lock 1 is then inserted into the various recesses formed in the side edge 2a of the door 2 and is secured thereto by countersunk, flathead screws 13b which are inserted into corresponding countersunk through-holes 13a in the forend plate 12 of the lock 1.

With a conventional lock, all pressure exerted on the front or rear surface of the door is transmitted as force through the vertical sidewalls of the principal mortise to the lock housing. Since the contact surface area between the housing of the lock and each of the vertical side walls is relatively small, the stress exerted on the vertical sidewalls for a given pressure applied to the front surface of the door is quite high. As soon as the stress on one of the vertical sidewalls reaches an upper threshold value, the sidewall fractures and the lock yields.

In the present invention, by providing the steel pin 14 not only has the Applicant increased the effective contact surface area between the lock 1 and the vertical sidewalls interposing the lock 1 and the front 3a and rear 3b surfaces of the door 2 (the contact surface area of the housing 10 plus that of the steel pin), but the effective thickness of those sidewalls is also increased (thickness of the vertical side walls between the lock housing and the front and rear surfaces respectively plus the effects of the increased thickness between the steel pin and the surfaces respectively). Accordingly, the upper threshold stress that the vertical sidewalls are capable of withstanding is increased, due to the effective increase in the thickness of the vertical

sidewalls, and the increase in the contact surface area permits the door to absorb greater pressure.

For test purposes, the present Applicant installed a standard lock into the side edge of a conventional soft wood door and activated the lock to secure the door to a surrounding frame. The door in this condition was subjected to multiple strikes from a sledgehammer and the lock yielded after 50 blows.

Under identical conditions, the Applicant repeated the above test using an identical soft wood door with the same standard lock but this time a steel pin having a diameter of 8mm and a length of 80mm was provided on the housing of the lock in accordance with the embodiment of the invention shown in Figs.

1 to 3. On this occasion the lock still had not yielded after 400 blows from the sledgehammer.

Accordingly, the present invention surprisingly and appreciably enhances the strength of a lock installed within a mortise in a conventional solid door without substantial modification to the width of the lock housing or the side edge of the door.

Although the majority of the external doors of a building are solid doors, there are numerous occasions when a mortise lock is installed in a cavity door. A partial plan view of such a door is illustrated in Fig. 4. The door 2'consists of a panel 3a'forming the front surface of the door 2', another panel (not shown) forming the rear surface of the door 2', and a plurality of support struts 21,22 therebetween, four of these struts defining the four edges of the door 2'.

To install the lock 1 as previously described into this door 2'a mortise (corresponding to the principal mortise 4 of the previous embodiment) is machined through an external strut 21 forming the side edge 2a of the door 2' to partially accommodate the housing 10 of the lock 1, a bore 6'is drilled through one of the internal struts 22 into which the steel pin 14 extends, and a

stepped recess 4a surrounding the channel in the external strut 21 is provided to house for the forend plate 12 of the lock 1. Although the internal strut 22 shown in Fig. 4 is vertical, it could alternatively be diagonal or even horizontal. It is feasible that the steel pin 14 may pass through and be supported by more than one internal strut 22. Alternatively, the housing 10 of the lock 1 and the steel pin 14 may be fully accommodated within the external strut 21 acting as the side edge 2a of the door 2'. As a further alternative, if the door 2'does not have any internal struts 22, the pin 14 may be accommodated within a bore formed in an external strut 21 opposing that in which the principal mortise is formed. So long as the steel pin 14 passes through a solid portion of the door 2', the strength of the lock 1 will be appreciably enhanced.

So far, the only anchor member of the lock 1 that has been described has been the steel pin 14. This is particularly beneficial as it is a relatively easy task to drill a cylindrical bore 6, 6' either through the principle mortise 4 of the solid door 2 or alternatively into the internal strut 22 of the cavity door 2'so as to accommodate the steel pin 14. However, this is not the only anchor member that the Applicant perceives.

Fig. 5 shows an alternative lock l'which differs from the previous lock 1 in that the anchor member is a steel plate 14'rather than a steel pin 14. This lock l'is installed within a door 2, 2' in exactly the same manner as previously described with reference to Figs 1 to 4 with the exception that a slot is machined through the principle mortise 4 or the internal strut 22 in place of the cylindrical bore 6,6'.

In all of the embodiments previously described, the anchor member extends backwards from that edge surface of the housing 10 which is remote from the forend plate 12. This is not an essential feature of the invention since it is believed that the strength of the lock will be enhanced no matter which

direction the anchor member extends or no matter from which surface of the housing 10 it extends so long as it extends into a solid portion of the door in a direction substantially parallel to the front and rear surfaces of the door.

Furthermore, it is envisaged that more than one anchor member could be provided. For example, as well as the steel pin 14 shown in Fig. 2 which extends from to the left of the lock housing, it is feasible that two further anchor members, preferably steel plates, could be provided, one extending upwards from the lock housing, the other extending downwards from the lock housing.

Fig. 6 shows a further embodiment of the present invention using a conventional mortise lock 1 with an extended forend plate 12'. On this occasion, rather than mounting anchor members directly onto the metal housing 10 of the lock 1, the anchor members are provided on three separate U-shaped channels 23,26 which are designed to slide over the housing 10. A steel pin 24, comparable to that illustrated in Fig. 2, is mounted on the rearmost channel 23 and extends backwards therefrom. The upper and lower channels 26 are identical, each having a steel plate 28 extending outwards from the housing 10 of the lock 1.

The lock 1 is installed within a door 2 as shown in Fig. 7. Again, the initial step is to machine out the respective recesses necessary to accommodate the lock 1 and channels 23,26 in the side edge 2a of the door 2. These include a principal mortise 4 to accommodate the channels 22,26 and the housing 10 of the lock 1, a cylindrical bore 6 extending backwards from the principal mortise 4 to house the steel pin 24 of the rearmost channel 23 and two slots 29, one extending upwards and the other extending downwards from the principle mortise 4, to accommodate the steel plates 28 of the upper and lower channels 26 respectively. In order to ensure that the extended forend plate 12' lies flush with the side edge 2a of the door 2, it is accommodated within a stepped recess 4a.

As in the previously described embodiments, communication holes 21 are machined through from the front surface 3a to the principal mortise 4 of the door 2 for the pivot shaft 19 and to enable a user to insert a key into the keyhole 17 of the lock 1, respectively.

After the various recesses and holes have been machined from the door 2, the U-shaped channels 23,26 are inserted into their respective positions with the anchor members extending into their respective recesses and the channels available to receive and engage the housing 10 of the lock 1.

Once the lock 1 has been accommodated within the side edge 2a of the door 2, it is secured thereto by countersunk, flathead screws 13b which are inserted into corresponding countersunk through-holes 13a in the extended forend plate 12'of the lock 1. In this particular example, the forend plate 12' has been extended so as to cover up the slots 29.

Another embodiment of the invention is illustrated in Fig. 8. In this instance, the entire housing 10 of the lock 1 is accommodated within a metal sleeve 30.

The sleeve 30 is provided with a steel pin 34 extending backwards therefrom and two steel plates 32, one extending upwards and the other extending downwards therefrom. The lock 1 is inserted into the sleeve 30 which has holes corresponding to the receiver hole 15 and keyhole 17 of the lock. The combination can then be installed in the door 1 within the recesses shown in Fig. 7 and secured thereto as previously described.

Although in the foregoing embodiments, the preferred material from which the anchor member is manufactured is steel, it is believed that anchor members made from any other metal would also improve the strength of the mortise lock.

While the largest application for a lock and anchor members according to this invention is probably building security, it is not the Applicant's intention to limit the invention to buildings solely as the lock and anchor members can be used for any other purpose that conventional mortise locks are used.

Furthermore, although the specific description of the embodiments of the invention has been directed to mechanical and manually operated locks, the present invention is equally applicable to electrical locks and those operated automatically or remotely.

Claims

1. A mortise lock for installation into a mortise formed in a side edge of a door having a front and a rear surface, the lock comprising: a housing containing locking elements; and an anchor member extending from an edge surface of the housing having a width which is less than that of the housing such that when the lock is installed in the mortise the anchor member extends from the mortise into a recess formed in a solid portion of the door in a plane substantially parallel to the front and rear surfaces of the door.

2. A lock according to claim 1, wherein more than one anchor member is provided, each being received in a respective recess.

3. A lock according to claim 2, wherein three anchor members are provided, the first anchor member extending form a rear surface edge of the housing and the other two anchor members extending from edges surfaces of the housing that are mutually perpendicular to the rear edge surface.

4. A lock according to claim 3, wherein the first anchor member is a steel pin that is received in a hole formed in a solid portion of the door.

5. A lock according to claim 4, wherein the other two anchor members are steel plates, each of which is received in a respective slot formed in a solid portion of the door.

6. A lock according to claim 3, wherein the anchor members are steel plates, each of which is received in a respective slot formed in a solid portion of the door.

7. A lining for a mortise formed in a side edge of a door having a front and a rear surface, the lining partially or completely receiving a housing of a lock and comprising: an engagement means to engage with the housing of the lock ; and an anchor member extending from the engagement means having a width which is less than that of the housing of the lock such that when the lining and the lock are installed in the mortise, the anchor member extends from the mortise into a recess formed in a solid portion of the door in a plane substantially parallel to the front and rear surfaces of the door.

8. A lining according to claim 7, wherein the engagement means is a Ushaped channel having a central cross-piece and two legs extending therefrom in a direction which is substantially perpendicular to the cross-piece to engage with the housing of the lock, and the anchor member extends from the central cross-piece of the engagement means in a direction opposite to that of the legs.

9. A lining according to claim 8, wherein more than one anchor member is provided on the cross-piece, each being received in a respective recess.

10. A lining according to claim 7, wherein the engagement means is a sleeve having an open end into which the lock is inserted.

11. A lining according to claim 10, wherein three anchor members are provided, the first anchor member extending from a rear edge surface of the lining which opposes the open end of the lining and the other two anchor members extending from edge surfaces of the lining that are mutually perpendicular to the rear edge surface.

12. A lining according to claim 11, wherein the first anchor member is a steel pin that is received in a hole formed in a solid portion of the door.

13. A lining according to claim 12, wherein the other two anchor members are steel plates, each of which is received in a respective slot formed in a solid portion of the door.

14. A lining according to claim 11, wherein the anchor members are steel plates, each of which is received in a respective slot formed in a solid portion of the door.

15. A mortise lock for installation into a mortise formed in a side edge of a door substantially as hereinbefore described with reference to and as illustrated in Figures 1 to 4 or Figure 5 of the accompanying drawings.

16. A lining for a mortise formed in a side edge of a door substantially as hereinbefore described with reference to and as illustrated in Figure 6 or Figure 8 of the accompanying drawings.