GB2349913A

GB2349913A - Lock for window or door

Info

Publication number: GB2349913A
Application number: GB0014982A
Authority: GB
Inventors: John Derek Mumford
Original assignee: Mumford & Wood Ltd
Current assignee: Mumford & Wood Ltd
Priority date: 2000-06-19
Filing date: 2000-06-19
Publication date: 2000-11-15
Anticipated expiration: 2020-06-19
Also published as: GB0014982D0; GB2349913B

Abstract

A sash window vent lock (1) comprises two independently extendable bolts (2, 3). The lock allows a window (28) to be opened to different degrees (30, 30').

Description

Lock for windows or doors

Description

The present invention relates to a lock for windows or doors particularly but not exclusively for a vertical sliding sash window.

Vent window locks are known which allow a vertical sliding sash window to be partly opened. They allow the top sash to drop or the bottom sash to be raised by a few tens of millimetres. This is enough for ventilation, but not enough for a person to gain entry through the window.

The present invention seeks to provide an improved lock.

According to the present invention there is provided a lock for a window or door which comprises first and second sliding parts, the lock comprising a first extendable bolt to prevent sliding of the first part beyond a first predetermined limit relative to the second part and a second extendable bolt to prevent sliding of the first part beyond a second predetermined limit relative to the second part.

The first and second bolts may be configured to be independently extendable and may be protrudable from a common plate.

The lock may further comprise first and second housings for receiving the first and second bolts respectively when in a retracted position.

According to the present invention there is also provided a window including the The window may be a sash window.

According to the present invention there is further provided a door including the According to the present invention there is also provided a method of locking a window or door which comprises first and second sliding parts, the method comprising providing a first extendable bolt to prevent sliding of the first part beyond a first predetermined limit relative to the second part and providing a second extendable bolt to prevent sliding of the first part beyond a second predetermined limit relative to the second part.

An embodiment of the present invention will now be described, by way of example, with reference to the accompanying drawings in which:

Figure 1 is a plan view of the front of a lock according to the present invention; Figure 2 is a cross-sectional view of the lock shown in Figure 1 along the line A-A; Figure 3a is a side view of the lock shown in Figure I with both bolts wholly retracted; Figure 3b is a side view of the lock shown in Figure 1 with both bolts fully extended; Figure 4 is a perspective view of the lock shown in Figure 1, together with part of a sash window; Figures 5a shows a vertical sliding sash window having a lock according to the present invention in a closed position; Figures 5b shows the sash window shown in Figure 5a in a first open position, Figure 5c shows the sash window shown in Figure 5a in a second open position.

Referring to Figures 1 and 2, a lock 1 according to the present invention comprises first and second retractable bolts 2, 3, first and second respective bolt cases 4, 5 and a mounting plate 6. The bolts 2, 3 are arranged to be independently extendable from their respective cases 4, 5 using a key (not shown). Each bolt 2, 3 and each respective bolt case 4, 5 is configured with a bolt extract ing/retracting mechanism well known in the art. The bolts 2, 3 are annular in construction with respective first and second collars 6, 7 at one end and are mounted to respective first and second plates 8, 9 by rivets 10, 11 having heads 12, 13 configured to engage the key.

Each bolt 2, 3, is free to rotate about its axis. The inside walls 14, 15 of the lock bolt cases 4, 5 are threaded. The key is inserted into the lurnen of the first bolt 2 so as to engage the first rivet head 12. Rotating the key rotates the rivet head 12, which in turn rotates the first plate 8. This moves the plate 8 back and forth within the first bolt case 4, taking the first bolt 2 with it. The second bolt 3 operates in a similar fashion. In this example, the bolts 2, 3 have an outer diameter of 10 mm and an inner diameter of 6 mm. The bolt cases 4, 5 are cylindrical and have a diameter of 16 mm and a length of 22 mm.

The mounting plate 6 has first and second apertures 16, 17 through which the bolts 2, 3 may respectively protrude. In this example, the apertures 16, 17 are offset from one another by 50 mm. The mounting plate 6 also has first and second bevelled screw holes 18, 19 for mounting the lock to the frame of a door or window. In this example the mounting plate is 3 mm thick, 18 mm wide and 67 mm long.

Referring to Figures 3a and 3b, when wholly retracted, the bolts 2, 3 are housed within first and second cases 4, 5 and first ends of the bolts 2, 3 are flush with the face of the mounting plate 6. When fully extracted, the bolts 2, 3 protrude the face of the mounting plate 6, by for example, 15 mm.

In this example, the bolts 2, 3, cases 4, 5 and mounting plate 6 are formed of brass, although other alloys, such as hardened steel, and elemental metals may be used.

Durable plastics may also be used. These parts may also have protective coatings.

Referring to Figure 4, the lock 1 is mounted to the interior side of a stile 20 of a top sash of a vertical sliding sash window (Figure 5a). A pair of holes (not shown) are drilled into the stile 20 to receive the first and second cases 4, 5. A recess (not shown) is also cut from the stile 20 in which the mounting plate 6 sits so as to be flush with the interior-facing side of the stile 20. The lock I is secured by means of first and second screws 21, 22. A striker plate 23 is configured on a rail 24 of a bottom sash (Figure 5a) in such a way so as to abut one of the bolts 2, 3 when extended and when the bottom sash is lifted or the top sash is dropped. The striker plate 23 sits in a recess and is secured by a third screw 25. In this example, the striker plate 23 has dimensions of 18 mm by 18mm by 3mm and is formed from brass, although other alloys or elemental metals may be used. The striker plate 23 may be made from plastic. Alternatively, no striker plate 23 may be installed in which case the rail 24 of the lower sash functions as a striker plate.

Referring to Figure 5a, the lock 1 is mounted to the top sash 26 and the striker plate 23 is located on the bottom sash 27 of a vertically sliding sash window 28. If both bolts 2, 3 are wholly retracted, such then the bottom sash 27 is free to move within the frame 29 relative to the top sash 26.

Referring to Figure 5b, if the second bolt 3, which in this example is the lower of the two bolts, is extended to its fullest extent, then the lower sash 27 may be raised until the striker plate 23, abuts the protruding second bolt 3. This leaves a gap 30 between the edge of the frame 29 and the bottom of the lower sash 27. In this example, this gap is 14 mm. This is a sufficient gap to provide ventilation, while narrow enough to prevent a hand, arm or leg to fit through. It will be appreciated that both the first and second bolts 2, 3 may be extended at the same time to provide additional security. It will also be appreciated that the lock 1 may be mounted in such a way that when a bolt 2, 3 is extended, the extended bolt 2, 3 locks the window in a closed position with no gap. For example, the lock 1 may be positioned lower down on the stile 20, so that the lower bolt 3, when protruding, abuts the striker plate 23 and holds the lower sash 27 tight in the closed position with no gap 30.

Referring to Figure 5c, if the first bolt 2, which in this example is the higher of the two bolts, is extracted to its fullest extent and the second bolt 3 is wholly retracted then the lower sash 27 may be raised until the striker plate 23, abuts the protruding first bolt 2. This leaves a wider gap 30' between the edge of the frame 29 and the bottom of the lower sash 27 than that if the second bolt 3 were protruding. In this example, this gap is 60 mm. This provides improved ventilation, while still providing adequate security.

The lock 1 has the advantage of providing different degrees of ventilation. For example, the arrangement shown in Figure 5b may be used for ventilating a room when security is important, for example during the night or when a room is unoccupied. The arrangement shown in Figure 5c may be used when increased ventilation is required room, for example during the day or when a room is occupied.

It will be appreciated that many modifications may be made to the embodiment described above. For example, the lock may be mounted to a door, in particular a horizontal sliding door. Two locks, one on each stile of the top sash, may be used. The lock may comprise more than two bolts.

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Claims

1. A lock for a window or door which comprises first and second sliding parts, the lock comprising a first extendable bolt to prevent sliding of the first part beyond a first predeterrnined limit relative to the second part and a second extendable bolt to prevent sliding of the first part beyond a second predetermined limit relative to the second part.

2. A lock according to claim 1, wherein the first and second bolts are configured to be independently extendable.

3. A lock according to claim 1 or 2, wherein the first and second bolts are protrudable from a common plate.

4. A lock according to any preceding claim, further comprises first and second housings for receiving the first and second bolts respectively when in a retracted position.

5. A lock substantially as hereinbefore described with reference to Figures la, 1b, 2a and 2b of the accompanying drawings.

6. A lock substantially as hereinbefore described with reference to Figures i a, 1b, 2a, 2b, 3, 4a, 4b and 4c of the accompanying drawings.

7. A window including a lock according to any preceding claim.

A sash window including a lock according to any one of claims I to 6.

9. A door including a lock according to any one of claims 1 to 6.

10. A method of locking a window or door which comprises first and second sliding parts, the method comprising: providing a first extendable bolt to prevent sliding of the first part beyond a 25 first predetermined limit relative to the second part and providing a second extendable bolt to prevent sliding of the first part beyond a second predetermined limit relative to the second part.