GB2276747A

GB2276747A - Anti-theft alarm system

Info

Publication number: GB2276747A
Application number: GB9306442A
Authority: GB
Inventors: Timothy Nalder Stephens
Original assignee: Individual
Current assignee: Individual
Priority date: 1993-03-27
Filing date: 1993-03-27
Publication date: 1994-10-05
Also published as: GB9306442D0

Abstract

There is described a theft alarm comprising a transmitter unit 2 and a receiver unit (7 fig. 3, not shown), the transmitter unit including a movement sensor 4, a control unit 5 and a transmitter 6 which transmits a signal to the receiver unit (7) when the transmitter unit is disturbed. The receiver unit (7) then emits a visual or audible alarm to alert the owner of the item to which the transmitter unit is attached that theft is being attempted. The transmitter unit is preferably receivable in a tubular component of a bicycle eg. the handlebars. <IMAGE>

Description

ANTI-THEFT DEVICE The present invention relates to anti-theft devices, and is particularly concerned with alarm devices for preventing theft of bicycles.

Alarm devices are known for attachment to bicycles which emit an audible alarm when the bicycle is disturbed. A major disadvantage of such devices is that they are generally readily visible since they are externally attached to the bicycle, and are thus accessible to be detached or disabled by a prospective thief prior to the removal of the bicycle.

The present invention seeks to overcome the disadvantages of prior cycle alarms by providing an alarm system for bicycles or the like which does not alert a prospective thief to its presence either visibly or audibly, but affords a warning to the owner of the bicycle that the machine is being tampered with.

According to the present invention, a cycle alarm system comprises a sensor and transmitter unit housed within the tubular frame of the bicycle, and including a power supply means, a sensor to detect unauthorised tampering or movement of the bicycle, and a radio transmitter to provide an alarm signal, the system further including a portable receiver capable of receiving the alarm signal transmitted by the radio transmitter and an audible or visual indication means activated by the receipt of the alarm signal.

The cycle alarm of the present invention advantageously includes a motion detector such as a trembler or similar inertia switch, or a mercury switch to detect movement of the bicycle. When movement is detected, the sensor activates a radio transmitter which emits a low-power transmission detectable by the receiver which is carried by the cycle owner. The cycle owner may then return to the cycle, in order to foil any theft attempt.

To further enhance the deterrent value of the device; an audible alarm may be attached to the cycle frame at a location different from that of the radio transmitter unit, the audible alarm also including a radio receiver so that emission of the radio alarm signal simultaneously warns the cycle owner of a theft attempt and also sets off an audible alarm attached to the cycle. The system is intended for use in conjunction with a conventional securing device such as a chain or shackle lock, rather than as a substitute there for.

An embodiment of the invention will now be described in detail, with reference to the accompanying drawings in which: Figure 1 is a schematic view of the installation of an alarm in a bicycle handlebar; Figure 2 is an enlarged schematic diagram of the alarm transmitter; and Figure 3 is a schematic view of the remote receiver.

Referring now to the drawings, there is shown a bicycle handlebar 1 of tubular construction, having inserted in one of its ends the alarm transmitter unit 2. The transmitter unit 2 may be concealed, for example by being installed inside a twist-grip gear, or may be covered using conventional handlebar tape or a rubber handlebar grip.

The transmitter unit 2 comprises a power source 3 such as a battery, a motion sensor 4 such as a trembler switch, inertia switch, mercury switch or the like, a control unit 5 and a transceiver 6.

Preferably the transceiver 6 is mounted at the end of the transmitter unit 2 nearest to the end of the handlebar 1, so that an antenna formed on the end face of the transceiver 6 may be exposed so as to suffer the least interference from the metallic handlebar tube. In Figure 3 there is shown the remote unit 7 to be carried by the cycle owner. This unit comprises a power source 8, a radio transceiver 9 with an antenna 10, a visual display 11, an audible warning device 12 and one or more control buttons 13 connected to the transceiver unit 9.

In use, the transmitter unit 2 is installed in the bicycle and when the bicycle is left, it is secured in the conventional manner to a post or other immovable object. The transmitter unit 2 is then armed, preferably by means of a radio signal emitted from the transmitter 9 of the remote unit 7. This signal is preferably a coded signal so that only the transmitter unit 2 associated with a particular bicycle is affected. The arming signal, when received by the transceiver 6 and given to the control unit 5 of the transmitter unit 2, places the transmitter unit 2 in an active mode in which movement or vibration detected by the sensor 4 causes a signal to be sent to the control unit 5, which in turn causes transceiver unit 6 to emit a coded radio alarm signal.

When this coded signal is received by the antenna 10 of the remote unit 7, the transceiver 9 of the remote unit 7 causes a display to appear on the visual display 11 and optionally an audible signal is emitted by the device 12. Control buttons or switches 13 may be provided so as to enable the user to cancel any alarm signal.

The remote unit 7 is preferably provided with control buttons or keys to enable the user to arm the transmitter unit 2 and to disarm the transmitter unit 2, as well as to suppress any audible or visual indications of alarm given by the remote unit 7.

In an advantageous development of the device, not shown in the drawings, the cycle itself may be fitted with a warning siren associated with a further radio receiver, so that when the transmitter unit 2 emits its coded radio alarm signal the warning siren attached to the cycle will emit a loud warning noise. This may be sufficient to deter a thief.

In use, the cycle owner may then simply secure his cycle in the conventional way and arm the transmitter unit 2 using the remote unit 7. The cycle owner can then be sure that, should his cycle be subjected to any motion or vibration, the transmitter unit 2 will ensure that a radio signal is sent out to alert the owner to this fact. By emitting a radio signal detectable only by the cycle's owner, the prospective thief is given no warning that the alarm has been raised and thus it may be possible for the owner to return to the cycle in time to catch the thief in the act.

If deterrence is felt to be warranted, the cycle can be fitted with a siren activated by the alarm radio signal, so that any tampering with the cycle will cause the transmitter unit 2 to send out the radio alarm signal simultaneously to the cycle's owner and to the siren unit, so that an audible alarm is raised which may well deter the thief from proceeding with his intentions.

While the transmitter unit 2 has been described as being installed within the handlebar end of the cycle, it is clear that the unit may be installed in any location on the cycle. Preferably the transmitter unit is concealed within the tubes forming the cycle frame or handlebars, with its antenna exposed so as to minimise interference with the radio signal. Alternatively, the unit may be fitted outside the cycle frame, where its visible presence may prove a deterrent to thieves.

In a further alternative embodiment, not shown, the transmitter unit is provided with a security key switch accessible when the unit is installed in the cycle, the security key switch being used to arm and disarm the transmitter unit as an alternative to a radio-activated system. Clearly, the security key switch may be of any suitable type, mechanical, electrical or electronic.

Advantageously, the security key arrangement is such that the unit is disarmed when a key is inserted into a receptacle in the unit, and is armed when the key is removed.

Claims

1. An anti-theft alarm system comprising a transmitter mounted on the article to be protected and actuated by a sensor which detects tampering or movement of the article, and a receiver capable of receiving signals from the transmitter and providing a visible or audible alarm signal.

2. An alarm system according to Claim 1, wherein the sensor and transmitter form a unitary assembly, and are linked to an independent power supply.

3. An alarm system according to Claim 1 or Claim 2, wherein the sensor and transmitter assembly is receivable within a tubular component of a bicycle or the like.

4. An alarm according to any preceding Claim, and further including an arming switch actuated by key means.

5. An alarm system according to Claim 4, wherein the key means comprises a switch whose contacts are closed by the removal of a key therefrom and opened when the key is inserted.

6. An alarm system according to any preceding Claim, wherein an audible or visual alarm on the vehicle is operated simultaneously with the actuation of the transmitter.

7. An alarm system substantially as herein described with reference to Figures 1, 2, and 3 of the accompanying drawing.