GB2329417A

GB2329417A - Automatically activated,audible warning system for lock keys

Info

Publication number: GB2329417A
Application number: GB9719933A
Authority: GB
Inventors: John Anthony Savage
Original assignee: Individual
Current assignee: Individual
Priority date: 1997-09-18
Filing date: 1997-09-18
Publication date: 1999-03-24
Also published as: GB9719933D0

Abstract

A standard Yale type lock would have a suitable enclosure 20 fitted to the inside of the door 10 and also a shroud plate 17 fitted to the outside of the lock. The shroud plate 17 is suitably insulated from the lock by a plastic or other material 22. The enclosure 20 consisting of a battery 21 and buzzer 19 which are suitably cabled to the latch component 13 and shroud plate 17. Upon insertion of the lock key 16 the circuit is made complete and the buzzer 19 is energised and transmits the audible signal. After removal of the key 16 the circuit is broken and the buzzer 19 no longer transmits the audible signal.

Description

AUTOMATICALLY ACTIVATED. AUDIBLE WARNING SYSTEM FOR LOCK KEYS Field of this Invention THIS INVENTION RELATES TO AN AUDIBLE WARNING SYSTEM WHICH IS ASSOCIATED WITH THE MECHANISM OF A LOCK TO INDICATE THAT A KEY HAS BEEN INSERTED.

Background to this Invention Many occasions arise when persons insert a key into a lock, and in particular into a Yale type lock and forget to remove it. This leads to a variety of situations, more specifically to unlawful intrusion of the property.

If an audible warning were energised at the insertion of the key, it is unlikely the key would be allowed to remain in the lock over and above the time required to open the enclosure to which the lock had been fitted.

It is the principal aspect of this invention that an audible warning will sound on the insertion of a key into a lock.

The embodiment of this invention comprises a means whereby an audible warning will be activated when a key has been inserted fully into the barrel of a Yale type lock. The complete entry of the key into the said barrel will make contact with an electric terminal and thereby complete an electric circuit.

AUTOMATICALLY ACTIVATED, AUDIBLE WARNING SYSTEM FOR LOCK KEYS An acoustic buzzer is housed in a battery-powered enclosure which is appropriately cabled to link with the latch mechanism and the tumblers in the lock barrel.

The embodiment of this invention relates in particular to the conventional domestic dwelling door locking system but can apply to any type of lock that requires a key to eject and withdraw the catch bar.

In this embodiment, the battery or other power source is sited preferably on the inside of the door or other enclosure, below the latch component of the lock assembly.

A contact plate is fitted to the barrel of the lock component ahead of an insulating ring. Appropriate electrical insulated cabling passes from the contact plate through the door material to the battery or other power source. An acoustic buzzer, flashing light or other type of warning system is included in the circuitry within the battery or other power source enclosure. When the key - and in particular a Yale type key is inserted into the barrel of the lock - the shoulders of the said key will touch the contact plate and thereby complete the electric circuit.

The warning will therefore be given that the key is in the lock and should be withdrawn in the interest of security.

AUTOMATICALLY ACTIVATED, AUDIBLE WARNING SYSTEM FOR LOCK KEYS A specific embodiment will now be more particularly described by way of non-limiting example only and with reference to the accompanying drawings, in which: Figure 1 - is a section through a door or other enclosure to which a Yale type lock has been fitted. It also shows the addition of the acoustic alarm system by way of example only.

Figure 2 - is an electrical circuit diagram applicable to the said alarm system.

According to Figure 1, there is shown the outline of a Yale type lock, fitted to a door 10 or other enclosure.

The barrel 11 is inserted fully within the material comprising the door 10 or other enclosure. The operating bar 12 passes from the barrel 11 to the latch component 13.

The said latch component 13 comprises the sliding latch bar 14 and the manual control knob 15. The said latch component 13 is on the inside of the said door 10. To turn the operating bar 12 from the outside, a key 16 must be inserted through the shroud plate 17 into the barrel 11 to move the wards (unseen) within the said barrel 11.

AUTOMATICALLY ACTIVATED, AUDIBLE WARNING SYSTEM FOR LOCK KEYS When the shoulders 18 on the key 16 touch the shroud plate 17, the buzzer 19 will be activated and remain activated until the key 16 is removed. The buzzer 19 is contained within an enclosure 20 which is fitted preferably just below the latch component 13 on the inside of the door or other enclosure. The buzzer 19 complies with existing technology already in the 'public domain' and therefore requires no specific description herein. It can be seen in Figure 1 that the electric circuit involves connecting the terminals of a battery 21 or other power source to the latch component 13 and to the buzzer 19. Other terminals of the battery 21, or other power source, are connected to the shroud plate 17 which is insulated from contact with the barrel 1 by a rubber, plastic or other material disc 22. In some instances, it could be preferred that the power source for the buzzer 19 is from the mains power supply which would then require the addition of a voltage reducing transformer (not shown) to replace the said battery 21. Using a battery 21 will require that its useful 'life' be observed and changed when necessary - this will obviously depend upon the frequency of use and the length of time the key 16 remains in the lock barrel 11.

AUTOMATICALLY ACTIVATED. AUDIBLE WARNING SYSTEM FOR LOCK KEYS Referring now to Figure 2, there is shown a circuit diagram suitable for the operation of the audible warning system for door locks. The said diagram is self-explanatory and needs no further explanation for a person 'skilled in the art'.

Claims

1. An automatically activated audible warning system for lock keys , comprising of a standard Yale type lock with means for producing the audible signal housed in an appropriate compartment on the inside of the door.

2 An automatically activated audible warning system for lock keys as claimed in claim 1 where means is provided to complete an electronic circuit upon insertion of the key in the lock.

3. An automatically activated audible warning system for lock keys as claimed in claim 2 where means is provided to activate the audible signal whilst the key remains in the lock.

4. An automatically activated audible warning system for lock keys as claimed in claim 3 where means is provided to stop the audible signal once the key has been removed from the lock.