GB2276412A - Improvements relating to alarm locks - Google Patents

Abstract

An electronic device 6 designed to be placed 7 over the body 1 of a shackle lock 1, 2 such that it can only be switched on or off when the shackle lock is opened and that when armed detects unauthorised tampering with the lock and sounds a high decibel sounder to deter the theft. <IMAGE>

Description

IMPROVEMENTS RELATING TO LOCKS.

There are many different types of mechanical lock used for security purposes generally consisting of a U shaped metal bar or shackle and a locking body into which the two ends of the shackle are inserted and locked so to form a completely encircled space between the bar and the body.

Typical locks of this type are the general purpose Daclock.

the bicycle shackle lock and bicycle wire loop lock.

Many mechanical locks may be opened by an unauthorised person either by picking the lock or by using bolt cutters or a hacksaw to physically cut or break the lock open.

The present invention provides an additional level of security for many mechanical locks of the type described above. It achieves this by providing a second level of deterrent to the thief and by attracting attention to any attempt being made to gain unauthorised access to the lock.

Cyclists are major users of high quality mechanical locks to prevent theft of their cycles as insurance is often invalidated if the cycle is not properly locked. However due to the increasing value of bicycles and the vulnerable locations in which cyclists have to leave them the number of cycle thefts is still high. Many thefts are achieved b breaking open the lock by either bolt cutters, hydraulic and mechanical jacks and hacksaws.

In an attempt to give a greater level of security for bicycles there have been various electronic alarms made available commercially but these have suffered from three major problems.

Firstly an electronic siren designed to attract attention may be noticed but is rarely acted upon. This is a result mainly of the reputation of car alarms for activating falsely. Consequently many cyclists are unwilling to leave their cycles guarded only by this means.

Secondly many of these devices require permanent attachment to the frame of the bicycle. It is difficult to produce a device that will fit a wide range of bicycle frames and to find enough free space on the frame to do so. Much free space is taken up with water bottles, tyre pumps and lock carriers etc.

Thirdlv the additional cost of another lock for a cyclist who is already using a quality mechanical lock is prohibitive. Also carrying two keys to unlock one bicycle is an annoying hindrance to the ease of use of the bicycle.

The present invention provides for solutions to these problems.

The invention consists in an alarm lock arrangement comprising a shackle member with two arm portions spanned by a common crosspiece lockable thereto, at least one such arm being selectively removable from the unlocked crosspiece to permit an article to be located within the shackle member and held therein on subsequent replacement and locking of the said arm: in which an alarm member is secured around the crosspiece to lie between the arm portions of the shackle and possesses an arming member attachable to one or other of the shackle arms for arming of disarming the alarm only when the shackle is open.

Preferably, an outwardly extending an alarm lock arrangement comprising an electrically operated electronic alarm. An alarm lock arrangement in which an outwardly extending arming member rotatable about a longitudinal axis terminates in a collar capable of placement about the said arm in either of two positions spaced at 180 degrees, one position being an armed position and the other a disarmed position.

and cnange between the two positions being possible only en the shackle is opened.

Such an alarm lock arrangement, containing an electric battery, may advantageously be dimensioned to fit with each respective end adjacent a shackle arm thereby to prevent battery removal while the shackle is locked.

The preferred embodiment consists of a battery powered electronic alarm unit that is fitted over a portion of the lock such that when the lock is in the closed position the alarm unit cannot be removed from the lock. Additionally the arming of the alarm unit is such that the alarm can only be armed or disarmed when the lock is in the open position.

This is achieved by a simple two position on/off rotary switch through which one end of the shackle passes when the lock is closed so preventing rotation of the switch between its on and off positions. In this way the alarm can only be armed or disarmed by the person in possession of the key to the lock.

The alarm unit when fitted to the lock and armed, electronically detects any unauthorised tampering with itself or the lock and emits a high decibel siren to attract attention of other people in the area and so deter the potential thief. This detection may be carried out by a number of means including vibration and passive infrared sensors.

The invention further provides solutions to the three shortcomings of existing electronic cycle alarms explained above.

Firstly the cyclist has tne choice to leave the bike at three levels of security i.e. electronic alarm only, mechanical lock only and Doth of the former together. The cyclist is not therefore forced to rely upon Just the electronic siren for security.

Secone'y the new invention is fastened not to the bicycle frame but to the lock itself which in most cases already has a carrying position on the bicycle frame. This overcomes the problem of space and universality of fitting as many cycle shackle locks share similar Dhysical dimensions.

Thirdly by allowing the arming of the electronic alarm to be achieved by a simple mechanical rotary switch the need for the alarm unit to have a keyed lock of its own is eliminated and the cyclist only needs to carry one key to use both devices. The alarm unit also costs less as it does not include a lock and key which traditionally form a significant Dart of the overall cost.

The invention will now be described with reference to tne following figures: Figure One showing a preferred embodiment installed on a shackle lock in two perpendicular views.

Figure Two showing a sectional view of the preferred embodiment with the shackle removed in two perpendicular views.

Figure One shows lock consisting of a body 1 with a U shaped shackle 2 having ends 3 and 4 inserted in the body The shackle 2 may be released from the body 1 by the the insertion of the key 5 in the body 1.

An enclosure 6 is held to the body 1 by means of a strap 7.

A collar 8 is fastened to a shaft 3 such that the end d of Xhe shackle 2 passes through the collar 8. The shaft 9 is supported by the enclosure 6 at bearing 10. Tne strap 7 and enclosure 6 may on'y be removed from the body 1 when the shackle 2 is removed thus allowing the strap 7 to slide over the body 1 in either of the directions sown by arrow Y.

Figure two shows the lock with the shackle 2 removed. With the shackle removed the collar 8 and shaft 9 are free to rotate in bearing 10 in the direction shown by arrow X. The shackle may be inserted through the collar 8 and into the body 1 with the collar in one of two angular positions separated by 180 degrees.

The enclosure 6 contains battery 21 connected to a circuit 20 via switch contacts 22. A sounder 23 is connected to the circuit 20 and emits sound through apertures 27.. The inner end 24 of the shaft 9 carries a conductor 25 such that when the collar 8 is rotated to one of its positions the conductor 25 makes a complete electrical circuit with the contacts 22 and supplies power to the circuit, and when the collar 8 is rotated in the direction of arrow X through 180 degrees the conductor 25 is separated from the contacts 22 and no power is supplied to the circuit 20. In this way depending on the angular position of the collar 8 when the end 4 of the shackle 2 is inserted through and locked into the body 1 the circuit will either be armed or disarmed.

The circuit may contain many preferable electronic features and methods of detecting unauthorised tapering with the lock. There should be an electronic delay period of about 15-30 seconds between the circuit becoming armed and the circuit becoming active to allow time for any disturbance created by the authorised user as the lock is secured to settle down. After that period whenever the circuit 20 detects unauthorised tampering the sounder 23 emits a high decibel alarm to cause acoustic discomfort to the potential thief and attract the attention of people in the vicinity.

There should also be a short delay of about 5 seconds between the circuit 20 sensing tampering and the sounder 23 being activated to allow the authorised user to unlock and disarm the circuit without sounding the alarm.

The battery 21 is retained in the enclosure 6 by a removable lid 26. The lid 26 is positioned between the enclosure 6 and the lock body 1 so that the lid 26 may not be removed and the battery 21 disconnected unless the complete alarm unit is first removed from the lock body 1 and this can only be achieved with the shackle 2 removed.

Claims (4)

1. An alarm lock arrangement comprising a shackle member with two arm portions spanned by a common crosspiece lockable thereto, at least one such arm being selectively removable from the unlocked crosspiece to permit an article to be located within the shackle member and held therein on subsequent replacement and locking of the said arm: in which an alarm member is secured around the crosspiece to lie between the arm portions of the shackle and possesses an arming member attachable to one or other of the shackle arms for arming of disarming the alarm only when the shackle is open.

2. An alarm lock arrangement as claimed in claim 1 comprising an electrically cperated electronic alarm.

3. An alarm lock arrangement as claimed in claim 2 in which an outwardly extending arming member rotatable about a longitudinal axis terminates in a collar capable of placement about the said arm in either of two positions spaced at 180 degrees, one position being an armed position and the other a disarmed position, and change between the two positions being possible only when the shackle is opened.

4. An alarm lock arrangement as claimed in claim 2 or 3, containing an electric battery, and dimensioned to fit with each respective end adjacent a shackle arm thereby to prevent battery removal while the shackle is locked.