GB2442473A

GB2442473A - Lock for door access flap such as letterbox

Info

Publication number: GB2442473A
Application number: GB0619664A
Authority: GB
Inventors: Robert Carson
Original assignee: Individual
Current assignee: Individual
Priority date: 2006-10-05
Filing date: 2006-10-05
Publication date: 2008-04-09
Also published as: GB0619664D0

Abstract

A lock for an access flap 2, eg letterbox or catflap, preferably includes a first member 11 fast with the inside face of the flap 2 and a second member 16, 17, 18 attached to a structural member of the door which engages with the first member in either a sliding or screwing manner. Restraints may be provided to prevent accidental movement of the lock. The lock may have anti-tamper measures and an alarm activated by forcing or breaking of the lock. A timer is preferably used to lock automatically lock the letterbox at night and in the evening. The lock is suitable for filling to existing single and double flap letterboxes and to new designs of letterboxes. A method of use is also provided.

Description

SECURITY APPARATUS

This specification relates apparatus for securing the access to houses, buildings and the like via letterboxes, cat flaps, etc. against unauthorised use.

In the housing market, there is a strong trend towards replacement doors and windows, using low-maintenance aluminium and plastic covered steel items. Improving security has been one key feature in the advertising of these products, with features such as additional hinges, multiple locks into the doorjamb, into the transom member.at the top and even into threshold at the bottom. While this improved security is highly commendable, one significant weakness in front doors is the letterbox -a rectangular hole, usually Iarpe enough to pass a sheaf of A4-size sheets of paper. The letterbox will have an outer flap.

Newer inner designs usually have both inner and outer, spring-loaded flaps and often draught excluding brushes. However, the principle of a letterbox is that it is an access through the door available for any passer-by in the street to use, if they so desire.

It is unfortunately not uncommon for letterboxes to be used for vandalism, e.g. posting' rubbish into the house and, in this context, dog faeces, are known. More serious is attempted arson, usually by inserting a burning rag, soaked in petrol, through the letterbox or even siphoning petrol directly into the house, via a tube. In many terraced properties, the bottom of the stairs is close to the front door so that any significant fire immediately inside the door effectively renders the stairs inaccessible and traps the occupants upstairs.

Clearly, if such people cannot be rescued very quickly, they are likely to die, either from smoke inhalation or in the actual fire. While some potentially hostile actions can be predicted, e.g. in areas where gangs' are known to operate, it is not unknown for people with grudges or mental conditions to conduct such activities on an apparently random basis, in respectable residential areas. Clearly, when a person has been on the receiving end of such activities, or knows someone who has, they will be nervous and require the reassurance of extra security measures.

There is, thus, a need for a means to secure letterboxes against unauthonsed access at times, when vandalism or related nefarious activities might occur, while retaining the letterbox for its legitimate purposes at other times.

I

According to the invention, there is provided a means of locking and unlocking the flap of an opening in a door, the means being operable from the inside of the door when said door is closed, and charactensed in that, when the means is in the locked position, the flap cannot be opened from outside the door and that, when the means is in the unlocked position, the flap may be opened from outside the door in the normal manner.

According to a first vanation of the apparatus of the invention, the flap is the externally opening flap of a letterbox.

According to a second variation of the apparatus of the invention, the flap is an access means for an animal.

According to a third variation of the apparatus of the invention, the locking means includes a firsi member fast with the inside face of the externally opening flap and engageable with a second member(s) of the locking means.

According to a fourth variation of the apparatus of the invention, the locking means includes a second member(s), engageable with said first member, which is / are either fast with a structural member(s) of the door or is I are connected to a member(s) fast with a structural member(s) of the door or is / are captively secured by a member(s) which is / are fast with a structural member(s) of the door.

According to a fifth variation of the apparatus of the invention, the locking means includes a screwed or bayonet-type of engagement between the first member and the second member(s).

According to a sixth variation of the apparatus of the invention, the locking means includes a sliding type of engagement between the first member and the second member(s).

According to a seventh variation of the apparatus of the invention, the locking means includes a means of preventing rotation of the flap about the spindle on Which the flap is mounted and about which it would normally rotate.

According to an eighth variation of the apparatus of the invention, the locking means is operated by a rotary form of movement.

According to a ninth variation of the apparatus of the invention, the locking means is operated by a sliding form of movement.

According to a tenth variation of the apparatus of the invention, the locking means is provided with restraints so that the operating means is restrained in both the locked and unlocked positions from inadvertent movement to the other position.

According to an eleventh variation of the apparatus of the invention, the locking means is provided with anti-tampering measures.

According to a twelfth variation of the apparatus of the invention, the locking means is provided with an alarm activated by forcing I breaking of the locking means from outside the door.

According to a thirteenth variation of the apparatus of the invention, a timing device is provided, able to lock the locking means at a first predetermined time and unlock the locking means at a second predetermined time.

According to the invention, there is provided a method of locking and unlocking the flap of an opening in a door compnsing:-i) providing a first member fast with the inside of a flap and engageable with a second member; ii) providing a second member either fast with a structural member of the door or fast with a member connected to a structural member of the door or captively retained by a member fast with a structural member of the door, and engageable with said first member; and iii) providing a means of engaging / disengaging said first and second members; charactensed in that the locking means may be engaged as and when required and disengaged as and when required.

According to a first variation of the method of the invention, the locking means is engaged for all / part of the evening and or the night time and disengaged during alI/ part of the day time.

In a first preferred design for a letterbox, the locking means consists of three members, viz:- 1. a member, with a tapped bore, fast with the inside surface of the external flap of the letterbox; 2. a member, able to bridge the gap of the letterbox on the inside of the door and having a hole therein; and 3. a screwed bolt.

To lock the letterbox, the member (2) is used to bridge the gap in the door formed by the letterbox, the screwed portion of the bolt (3) is passed through the hole in the bridge member, engaged with the screw thread in the tapped member (1) and screwed until it S finger tight. ie. there is no slack in the system, and the flap of the letterbox cannot be lifted, even by a small amount. To unlock the letterbox, the bolt is unscrewed and removed, together with the bridge member, and the flap is freed to open again.

The principle of the invention is applicable to both existing letterboxes and to new ones, e.g. as supplied in replacement doors. With new letteiboxes, the locking mechanism could be located internally within the transom carrying the letterbox. In this case, a preferred design uses a U-shaped staple(s) provided on the inner su,face of the external flap of the letterbox and an engaging bolt(s), located within the transom. Preferably, the bolt(s) is I are slidable into the U' of the staple to lock the flap from opening. A third preferred alternative is to provide a member, which is movable into a position to stop the rotation of the letterbox about its mounting spindle, so that it cannot rotate out of the dosed position.

Anti-tamper devices can be provided to prevent meddling with the locking means from outside the door. In practice, the letterboxes would probably be locked in the evening, possible as early as tea time in areas where vandalism in the early evenings could be expected. Unlocking in the mornings would occur before the time of the first of the postal or paper deliveries. As such deliveries could come early in the morning, electronic locking and unlocking at predetermined times may be provided. An alarm may be provided, activatable if the tampering with the letterbox flap is detected.

For a clearer understanding of the invention and to show how it may be camed into effect, reference will now be made, by way of example only, to the following drawings in which:-Figure 1 is a diagrammatic, sectional elevation of a conventional, double-flap

letterbox (Prior Art);

Figure 2 is a diagrammatic, sectional elevation of a first security means, according to the invention, fitted to an existing, conventional, double-flap letterbox; Figure 3 shows a diagrammatic, sectional elevation of the principle of the first security means fitted to an existing, conventional, single-flap letterbox; Figure 4 is a diagrammatic, sectional elevation of a second security means, according to the invention, fitted to a new, double-flap letterbox; Figure 5 is a diagrammatic, sectional elevation, along line shown in Fig. 4 (looking in the direction AA), of the second security means fitted to a new, double-flap letterbox; and Figure 6 is a diagrammatic, sectional plan, along the line BB shown in Fig. 4, of the second security means fitted to a new, double-flap letterbox.

In the following description, the same reference numeral is used for the same part in different drawings or for different parts fulfilling the same function. Though many of the Figures are sections, the use of hatching has been minimised to give clearer drawings.

Fig. 1 shows a conventional (Prior art), double-flap letterbox 1, such as fitted in most new, or replacement doors. It consists of an outer flap 2 and an inner flap 3, each mounted on respective spindles 5 and 6 and closed by springs (not shown) but also symbolised by reference numbers 5 and 6. Mountings 7 are attached to door structure 4 and surrounds I rain shields 8 are also shown. For clarity, draught excluding brushes are omitted.

When the postman wishes to deliver letters he opens flap 2, which rotates 9 about spindle 5, and inserts the letters, which push open 10 inner flap 3, allowing the letters to drop on the inside of door 4. In order to prevent unwanted items to be admitted to the inside of door 4, it is necessary to prevent flap 2 from being opened from the outside.

Fig. 2 shows one method by which this can be accomplished. A tapped ferrule 11 is brazed or soldered 12 to the inside face of flap 2 and a long bolt 17 is inserted through a matching hole 21 in inner flap 3 and screwed 14 into ferrule 11 via knurled bolthead 16.

The large diameter knurled head 16 provided is easy to use and finger tightness will be adequate for this application.

To ease the alignment and engagement of bolt 17 with screw thread 14. boss 18, with a bore 21, is brazed or soldered 12 to the outer face of flap 3, as shown. The additional length of hole 21 assists alignment of bolt 17 with ferrule 11, along centreline 15.

Additionally (Figs. 2 & 3), bolt 17 has a pointed end 20 and ferrule 11 has a conical lead-in 13 to guide the point 20 of bolt 17 into engagement with thread 14.

Bolt 16, 17 is provided with a means 19 so that it may be held captive, e.g. by a short length of chain (not shown), to door 4 so that it is always available for use. The method of use of the security apparatus is intended to be that bolt 16, 17 would be screwed into position to lock outer flap 2 in the evening and left until early the following morning, wfen it would be unscrewed and pulled out of boss 18 so that the letterbox I could be accessed normally for the delivery of mail or newspapers, etc. By locking the letterbox in the evening and overnight, when vandalism and anti-social activities are most likely to occur, the occupants should be able to sleep peacefully in the knowledge of the additional security provided.

While the invention described would not be proof against determined aggression from a resolute felon, e.g. with a jemmy or other equipment, use of such tools to break the letterbox flap 2 would cause considerable noise and be likely to alert both the occupants and neighbours. Thus, as most vandalism and criminal activities tend to occur at night, when it is quiet, felons rely on creating a minimum of noise and the security device of the invention will provide a considerable degree of reassurance to the occupants of the property. Alarms detecting either noise or attempts to fore flap 2 may be provided, if required.

Not all existing letterboxes are of the two flap (Fig. 1) design, many have just a single flap (Fig. 3). Here, ferrule Ills attached to the inside of flap 2, as previously described, but it is necessary to provide a reaction member 22 to bridge the lefterbox gap on the inside of the door. Member 22 is mounted 24, via hinge 23, on the inside of door 4. Flap 22 may be hinged upwardly 1OA until stop 25 contacts door 4. Bolt 16, 17 is inserted through hole 21 in boss 18 and member 22 and screw 17 engaged with thread 14 on centreline 15, as shown.

Both the arrangements of the invention shown in Figs. 2 and 3 are means by which the principle of the invention may be applied to existing letterboxes. Where new letterboxes are to be fitted, e.g. for new or replacement doors, the means of the invention may be built in to the structure of the door 4, i.e. into transom 31 (Fig. 6). A diagrammatic sectional arrangement of one means of applying the principle of the invention is shown in Fig. 4.

Here, staple(s) 26 is brazed or soldered 12 onto the inner face of outer flap 2, so that bolts 27, located in guides (not shown) in transom 31 of door 4, may be engaged therewith, as shown.

Fig. 5 shows a side elevation of the Fig. 4 arrangement and of the location of staples 26A and 26B at the sides of and on the inside face of flap 2, i.e. as seen looking in the direction of arrows M, from the inside of the door. Bolts 27A and 27B may be slid 28A and 288 respectively to engage with staples 26A and 268. In Fig. 5, bolt 27A is shown disengaged from staple 26A, i.e. allowing outer flap 2 to be opened, and bolt 27B is shown engaged with staple 268, locking flap 2 against being opened. Symbol 32 indicates that the length of the letterbox has been shortened for diagrammatic purposes.

Fig. 6 shows a sectional plan view through the letterbox shown in Fig. 4 along the line BB.

Sections 31 of the transom of door 4 are shown at either side of the letterbox 1. Staples 26 are shown on either side of the inside face of letterbox 2 and, as with Fig. 5, bolt 27A is shown in the unlocked position and bolt 278 in the locked position. Bolts 26 are slid by moving knobs 30 via members 29. Both bolts 26 are slid in guides (not shown) using knobs 30 located in slots (not shown) through transom members 31. As shown, knobs 30 are accessble only from the iride of the deor and would be unobtrusive items on transom 31 at either side of inner flap 3 of letterbox 1.

Simple sliding means 2, 30 are shown in Figs. 5 and 6 but other operating arrangements are equally possible. For example, a single mechanism could be provided to operate both bolts 26 simultaneously or knobs 30 could be rotated to move bolts 26, e.g. via a toothed mechanism. These other arrangements could be less vulnerable to being tampered with, e.g. by someone outside trying to push back bolts 26. Key operated locking means are also possible.

As mail and papers can be delivered very early in the morning, often before the occupants are awake, automatic operation of the locking means on a timed basis can be provided.

This would require powered to be supplied to door 4, e.g. via the hinged jamb, and a timing means provided. The timer could be set to lock the mechanism at a first predetermined time and unlock it at a second predetermined time. With a power supply to the door, a powerful alarm could be provided, though this would have to be able to distinguish between the effect of wind on flap 2 and attempts to force an entry.

A further method of implementing the invention is also shown n Fig. 4. Here, member 33 is moved 34 to the left, to the locked position (as shown), where the end 2A of flap 2 would contact it if attempts were made to open flap 2, i.e. to rotate it 9 about spindle 5. To unlock the letterbox, member 3 is moved 34 to the right, to retract it fully into the body of door 4.

Member 33 is shown dashed to indicate that it is an option to the main locking principle shown in Fig. 4 and to indicate its two locked and unlocked positions.

Though the description above has been directed towards letterbox security, the invention is equally applicable to other access means in doors, such as animal flaps, e.g. cat flaps.

The main reason for the invention is letterbox security via the front door, accessing the street. However, in many cases, there is also access to the back door and the security afforded by the principle of the invention may be required here too.

The apparatus and method of use of the invention will offer greatly increased protection to innocent people who might be the subject of planned or random acts of vandalism or arson. For people who have either suffered such incidents previously, or have a particular fear of them. the invention will give peace of mind, on which it is not possible to place a monetary value. The skilled man will understand a large number of ways to put the invention into effect, all falling within the scope of the principles taught herein.

Claims

Claims: 1 Apparatus providing a means of locking and unlocking the flap

of an opening in a door, the means being operable from the inside of the door when said door is closed, and charactensed in that, when the means is in the locked position, the flap cannot be opened from outside the door and that, when the means is in the unlocked position, the flap may be opened from outside the door in the normal manner.
2 Apparatus for locking and unlocking the flap of an opening in a door, as claimed in claim 1, wherein the flap is the externally opening flap of a letterbox.
3 Apparatus for locking and unlocking the flap of an opening in a door, as claimed in claim 1, wherein the flap is an access means for an animal.
4 Apparatus for locking and unlocking the flap of an opening in a door, as claimed in claims 2 or 3, wherein the locking means includes a first member fast with the inside face of the externally opening flap and engageable with a second member(s) of the locking means.
5 Apparatus for locking and unlocking the flap of an opening in a door, as claimed in claim 4, wherein the locking means includes a second member(s), engageable with said first member, which is / are either fast with a structural member(s) of the door or is I are connected to a member(s) fast with a structural member(s) of the door or is / are captively secured by a member(s) which is I are fast with a structural member(s) of the door.
6 Apparatus for lacking and unlocking the flap of an opening in a door, as claimed in claims 4and 5, wherein the locking means includes a screwed or bayonet-type of engagement between the first member and the second member(s).
7 Apparatus for locking and unlocking the flap of an opening in a door, as claimed in claims 4 and 5, wherein the locking means includes a sliding type of engagement between the first member and the second member(s).
8 Apparatus for locking and unlocking the flap of an opening in a door, as claimed in claims 2 and 3, wherein the locking means includes a means of preventing rotation of the flap about the spindle on which the flap is mounted and about which it would normally rotate.
9 Apparatus for locking and unlocking the flap of an opening in a door, as claimed in claims 6-8, wherein the locking means is operated by a rotary form of movement.
Apparatus for locking and unlocking the flap of an opening in a door, as claimed in daim 6-8, wherein the locking means is operated by a sliding form of movement.
11 Apparatus for locking and unlocking the flap of an opening in a door, as claimed in any preceding claim, wherein the locking means is provided with restraints so that the operating means is restrained in both the locked and unlocked positions from inadvertent movement to the other position.
12 Apparatus for locking and unlocking the flap of an opening in a door, as claimed in any preceding claim, wherein the locking means is provided with anti-tampering measures.
13 Apparatus for locking and unlocking the flap of an opening in a door, as claimed in any preceding claim, wherein the locking means is provided with an alarm acth,ated by forcing I breaking of the locking means from outside the door.
14 Apparatus for locking and unlocking the flap of an opening in a door, as claimed in any preceding claim, wherein a timing device is provided, able to lock the locking means at a first predetermined time and unlock the locking means at a second predetermined time.
A method of locking and unlocking the flap of an opening in a door comprising:-I) providing a first member fast with the inside of a flap and engageable with a second member ii) providing a second member either fast with a structuraá member of the door or fast with a member co ndfed to a structural member of the door or captively retained by a member fast with a structural member of the door, and engageable with said first member; and iii) providing a means of engaging F disengaging said first and second members; charactensed in that the locking means may be engaged as and when required and disengaged as and when required.
16 A method for locking and unlocking the flap of an opening in a door, as claimed in claim 15, wherein the locking means is engaged for all / part of the evening and or the night time and disengaged during all I part of the day time.
17 Apparatus and method for locking and unlocking the flap of an opening in a door, as described in and by the above statement, with reference to the accompanying drawings.