GB2260009A

GB2260009A - Electronic bicycle alarm

Info

Publication number: GB2260009A
Application number: GB9119171A
Authority: GB
Inventors: Keith Martin Clarke
Original assignee: Individual
Current assignee: Individual
Priority date: 1991-09-07
Filing date: 1991-09-07
Publication date: 1993-03-31
Also published as: GB9119171D0

Abstract

An electronic bicycle alarm 6 that can be armed/disarmed with the cycle standing or laying in any position or orientation. The major feature of the invention is that the alarm is located inside the cycle frame e.g. seat stem 4 to afford maximum protection from the weather and tampering. The alarm sounder may be external for maximum audibility. The arming/disarming mechanism may be external to allow for easy access. The alarm unit is armed/disarmed using either infra-red, ultra- sonic, radio, electrical or mechanical methods. <IMAGE>

Description

ELECTRONIC BICYCLE ALARM DESCRIPTION This invention relates to an electronic bicycle alarm.

The alarm was designed to fill the apparent gap in the bicycle security market. The alarm unit has been designed to iit inside the frame of a bicycle in order to give it maximum protection from being tampered with, vandalism and the weather.

The favoured place for fitting the alarm would be inside the hollow seat tube or the hollow seat stem.

The alarm unit provides an audible indication/warning in order to deter a would-be thief and to alert the owner and/or passers by that the bicycle is being tampered with. The alarm unit is activated b any movement or vibration applied to the bicycle. The alarm unit can be armed/disarmed and activated with the bicycle standing or laying in any position or orientation.

The alarm sounder itself may be separate from the main unit to enable its use in bicycles with solid seat stems (this configuration can also be used with hollow seat stems). The reason for this is that it would not be possible to hear the alarm from inside the frame if the seat stem was solid. Hence, in this case, the alarm sounder would be fixed to an area under the seat (either on top of the stem, onto the seat frame, or around the seat stem).

The alarm unit may be armed or disarmed by means of a code. This would be entered by either an electronic key pad, a coded radio, ultra-sonic, or infra-red transmitter, or an electrical/ mechanical key switch. The key pad and key switch would be mounted anywhere external to the cycle frame. The favoured place would be under the seat, attached to the seat frame or the seat stem.

According to the present invention the alarm unit consists of an audible alarm sounder, an arming/disarming circuit, a detection and timing circuit, and finally an alarm sounder driving circuit. The unit can be powered by 2,3 or 4 'AA' (equivalent to HP7, UM3, Mignon, LR6, MN150Q) or 'AAA' (equivalent to Hip16, UM4, Micro, LR03, MN2400) type batteries.

The whole unit is contained in a suitable metal/plastic container for use inside the bicycle frame.

A specific embodiment of the invention will now be described b way of examples referring to the accompanying drawings in which: Figure 1 shows the alarm unit in position inside the bicycle frame.

Figure 2 Shows the alarm unit in position with the alarm sounder separate to the main unit.

ire 3 shows the basic configuration of the alarm container.

Figures 4a, 4b & 4c show the ways in which the alarm can be armed/disarmed.

Figure 5 describes the basic block diagram of the alarm unit circuit for coded radio, ultra-sonic, infra-red & BR< key pad operation.

Figure 6 describes the basic block diagram for key switch operation.

The alarm unit 6 will be held inside the frame 4 or seat stem 3 {Figure 1) by means of spring tensioned grips 8 that will 1 firmly grip the inside of the hollow seat frame 4 or seat stem 3. The feed wire 7 will be fed up the hollow seat stem 3 for connection to an external arming/disarming device (figures 4a & 4b).

Figure 2 shows the configuration of the unit in solid seat stem bicycles. In this instance, the sounder feed wire lia and the arm/disarm wire 11 will be thin in construction to allow them to be fed up the side of the seat stem instead of through it. The sounder 9 will cover and guard the sounder wire to prevent it from being cut. The sounder will be fixed firmly to the seat stem by some suitable attachment 10.

Figure 3 shows the alarm unit 13 with one of its two spring tensioned grips 18. The sounder 14, sounder driving circuit 15 and decoding (arming disarming) 16 circuit areas are shown. The remainder of the space is for batteries.

The kev pad configuration (Figure 4a) will consist of between three and five keys 20. The code will contain up to nine figures. in order to facilitate easy memory of the code, the key pad 20 will have letters instead of numbers. For example, if the unit has four keys, the letters A,B,E,Y may be used. A typical code may then be BABYABBEY (which reads BABY ABBEY). Hence only two or three words have to be learnt instead of a nine figure code. With nine figures and four keys, tampering with the key pad will yield a 1 in 262,144 chance of getting the correct code at the first attempt.

Figure 4b shows that the unit can be armed or disarmed by a mechanical key switching unit 23 or an electrical key switching unit 22 & 24. Each unit will have'a code which will arm or disarm the unit. Inserting the electrical key 24 into the key slot 22 will disarm the unit. Removing the key will arm it.

Figure =c snows that no part of the alarm unit iil be external to the frame when it is constructed in this way. The unit 29 will be armed/disarmed by a radio, ultra-sonic or infra-red signal from the transmitter unit 28. Ultra-sonic 26 and infra-red 25 sensors are shown external to the frame. This configuration will offer maximum protection against tapering.

In the coded radio ultra sonic, infra-red or key pad configuration (Figure 5) the alarm is activated when pin 'x' of the counter chip is at logic zero. The alarm is de-activated when pin 'x' is at logic one. Pin x can be activated/deactivated by clocking the counter circuit so that pins 'abcd' will, in sequence, go from logic zero to logic one and back to logic zero each time the circuit is clocked.

If the correct code is entered via the key pad, radio, ultra-sonic or infra-red decoder circuit 30 then the counter will successfully clock around to pin 'x' and disarm the unit.

If the incorrect code is entered, the circuit will reset back to pin 'a' the instant an unexpected value is entered. For example, if the correct code is ABZBAZB, and the code entered is AB2BB... then the code at the last B will be incorrect and the alarm will reset via N3.

The purpose of D1, D2, D3, D4, D5, D6, & D7 is to ensure one way current flow and allow the clocking circuit and reset circuit to operate without interfering with each other. With the correct code entered, the unit will be disarmed. By pressing any key on the key pad or transmitter (28 Figure 4), the alarm will become armed and the circuit will reset to pin 'a' which will rise to logic 1.

The physical configuration of D1, D2, D3 & D4 actually determines the physical code. If the Counter IC is assumed to be reset, pin 'a' will be high and flag Z needs to be connected via the key pad or coded radio, ultra-sonic or infra-red 30 circuit to the common line which supplies N2. This will then clock the circuit around to pin 'b' and so on. The correct code in Figure 5 is shown to be ZBBA. If the incorrect flag is connected to the common line then C3 will discharge and hence the reset pin on the Counter IC will be operated via N3. For simplicity, only a four figure code circuit is drawn. The actual circuit will have up nine figures in the code.

When the unit is armed, any movement or vibration at VSW1 will set off the alarm. R1 & C1 determine the maximum alarm sounding time before the sounder is turned off. The circuit always remains armed until the correct disarming code has been entered.

When the correct disarming code is entered, D8, R2, C2, & BR< T2 enable the alarm sounder to bleep momentarily to inform the user that the correct code has been registered. Pressing any key after arming will activate another bleep through N1, D9, R2, C2 & T2 to inform the user that the unit is now armed. The purpose of D8, D9, D10 & Dll is to ensure that the alarm trigger and alarm bee lines do not interfere with each other.

In the key switch configuration, the circuit is greatly simplified to that shown (Figure 6). The voltages at point A & BR< B have to be at the correct level to ensure that the circuit is disarmed or armed. To disarm the circuit an electrical or mechanical key must be connected to force the correct levels at points A & B. Each key will have a unique code and it will not be easy to 'hot wire' the circuit to disarm it. The unit will not indicate when it has been disarmed. Removal of the key or resetting the mechanical switches (Figure 4b) will arm the alarm unit.

To disarm the unit, the voltage at point A must be high whilst the voltage at point B must be low. If these conditions are not met then the circuit will always be armed. Once armed, any vibration or movement will activate VSW1 which will activate the alarm sounder. C1 & Rl determine the maximum time that the alarm sounder remains on before switching it off. The unit is always activated until the correct key switch is inserted.

In all the circuits described, the power is always applied to the circuit. There is no on/off switch. The extremely low power consumption of the circuit makes this possible.

Claims

ELECTRONIC BICYCLE ALARM

CLAIMS 1. An electronic bicycle alarm that is located inside the frame, seat stem or handle bar of a bicycle. The alarm comprises of an audible alarm sounder, an arming disarming circuit, a detection and timing circuit and an alarm sounder driving circuit.
2. An electronic bicycle alarm as claimed in claim 1 whereby the alarm can be armed/disarmed and activated with the cycle being in any position or orientation.
3. An electronic bicycle alarm as claimed in claim 1 whereby the arming/disarming circuit is operated by either an infra-red, ultra-sonic, radio or electrical/mechanical key device.
4. An electronic bicycle alarm as claimed in claim 1 whereby the alarm sounder my be external to the cycle frame, seat stem or handle bar to allow for maximum audibility of the sounder.
5. An electronic bicycle alarm as claimed in claim 1 whereby the arming/disarming mechanism may be external to allow for easy access.

6. An electronic bicycle alarm as discussed herein with reference to figures 1-6 of the accompanying drawings.

Amendments to the claims have been filed as follows 1. An electronic bicycle alarm comprising of a battery, an alarm sounder, an alarm sounder driver circuit, a special vibration switch and associated detection circuit, and an arming/disarming circuit.

2. An electronic bicycle alarm as claimed in claim 1 whereby the alarm can be armed /disarmed and activated with the cycle being in any position or orientation 3. An electronic bicycle alarm as claimed in claim 1 whereby the arming/disarming circuit is operated b either an infra-red, ultra-sonic, radio or electronic key device.

1 An electronic bicycle alarm as claimed in claim 1 whereby the alarm sounder is to be fitted external to the cycle frame or seat stem to allow for maximum audibility of the sounder 5. An electronic bicycle alarm as claimed in claim 1 whereby the arming/disarming mechanism may be external to allot for easy accesss.
6 An electronic bicycle alarm whereby the main unit is located inside the bicycle frame for protection from the weather and tampering.
7. An electronic bicycle alarm as discussed herein with reference to figures 1-6 of the accompanying drawings.