GB2286476A

GB2286476A - Motion sensing alarm suitable for attachment to bicycle

Info

Publication number: GB2286476A
Application number: GB9402698A
Authority: GB
Inventors: Stephen Thomas Williamson
Original assignee: Individual
Current assignee: Individual
Priority date: 1994-02-11
Filing date: 1994-02-11
Publication date: 1995-08-16
Also published as: GB9402698D0

Abstract

Sound generator 15 emits an intermittent, audible signal when motion causes pin 17 to contact loop 20 thereby completing a circuit. The alarm is primed and deactivated by entering a code via keys 21 - 24. Several successive incorrect codes will activate generator 15. The alarm is incorporated in a housing which is suitably shaped for attachment to the frame of a bicycle. <IMAGE>

Description

ALARM This invention relates to an alarm and is particularly concerned to provide an alarm that gives an audible signal when it is attached to an object that is subjected to unauthorised movement, especially theft.

The invention is particularly useful as an alarm attached to pedal cycles but can similarly be used to protect motorcycles, boats and other vehicles. It will be further described with reference to an alarm for pedal cycles, particularly bicycles, although it will be appreciated that it is not intended to be limited thereto.

Various types of devices have previously been proposed to protect bicycles from theft. They fall into two basic types.

The first type is a mechanical locking device that is used to secure the bicycle to an immovable object, e.g. a lamp post or a fence. Such devices tend to be heavy and so undesirable for carriage when the bicycle is in use or lighter and hence less secure against a determined thief armed with, for example, cutters. The second type is an audible alarm in which unauthorised movement is intended to activate the alarm.

Mercury switches have been used as the activation means.

Audible bicycle alarms currently available have not met with much commercial success; it is believed that they are too large, and hence vulnerable to detachment by a determined thief, and relatively expensive.

The present invention aims to provide an audible alarm which can be securely fixed to an object such as a bicycle and which provides a loud audible warning at a reasonable cost.

Accordingly, the invention provides an alarm for attachment to a moveable object, the alarm comprising a housing containing a motion detector, electronic control means, an electrical power source, and a sound generator, priming means being provided on an exterior wall of the housing, whereby when the alarm is primed, movement of the object causes closing of an electrical circuit by the motion detector whereby the control means activates the sound generator.

Preferably the electronic control means are arranged to activate the sound generator intermittently once the motion detector has closed the electrical circuit and hence activated the system. Thus, for example, an initial movement of the object, e.g. bicycle, can cause a brief initial sound alarm.

If no further movement takes place within a predetermined time, say 20 seconds, the electronic controls then deactivate and return the alarm to its 'alert' or primed mode. If further movement does take place within the predetermined time, the control means re-activate the sound generator. The alarm can then sound continuously for, say, 60 seconds and then stop for say, 20 seconds and repeat this cycle for so long as movement continues.

The power source is preferably a battery, e.g. a 9 volt battery, and the above-described intermittent alarm means is a useful power saving means.

The initial brief alarm sound is useful to cater for circumstances such as a bicycle falling over, when a continuously operating alarm would not be desirable.

The priming means may be, for example, key operated lock but is preferably a security code that can be entered by pressing appropriate buttons on the housing wall. The electronic control means may be set up to accept the same or a different code for priming and then deactivating the alarm.

The motion detector is preferably a suspended wire, e.g. of copper which passes through a corresponding contact, e.g. a loop of wire. In the normal primed state there is a gap between the wire and the contact which constitutes a break in the electrical circuit to the control means. Movement of the object to which the alarm is attached causes rotation of the suspended wire into contact with the contact, completing the circuit and hence activating the alarm.

The sound generator may be any suitable electrically activated source. For example it may be of the piezoelectric crystal microphone type, examples of which are commercially available.

The sound generator can, therefore, be quite small but can emit a loud alarm of the order of more than 100 decibels, e.g. 110 to 120 decibels.

The housing is preferably a lightweight plastics or rubber moulding which is waterproof and shockproof. It can be small, e.g. up to a maximum of 65 x 90 x 40 mm, and lightweight, e.g. up to about lOOg. The electronic control means, usually in the form of a printed circuit board, the sound generator and motion detector can be extremely lightweight and the bulk of the weight of the contents of the housing will normally be provided by the battery.

The housing may have one wall shaped to be attached to a portion of a bicycle frame, i.e. it may be recessed to conform closely to a tubular frame portion, and it may be attached to the bicycle or other object by a convenient means, e.g. strap means. Preferably, however, it is attached by means of a circlip which can encircle a portion of the bicycle frame in a relatively inaccessible position, e.g. immediately underneath the saddle. Although such a position removes the visible deterrence effect of the alarm, this may be more than compensated for by its surprise effect when triggered.

The invention is further described by way of example only with reference to the accompanying drawings in which: Figure 1 is an exploded perspective view of an alarm of the invention; Figure 2 is a plan view from above of the alarm; Figure 3 is a plan view of the front wall of the housing; Figure 4 is a circuit diagram showing one form of electronic control system; and Figure 5 is a more detailed circuit diagram.

As shown in Figures 1,2 and 3, the alarm 10 comprises a generally box-like housing 11 having a removable front wall 12. Mounted within housing 11 is a printed circuit control board 13 on which are mounted a removable 9 volt battery 14, a sound generator 15 and a motion detector 16. Motion detector 16 comprises a wire 17 pivoted at 18 about a support 19 attached to control board 13 and a contact in the form of a loop 20 also attached to the control board. In the normal rest position there is no contact between wire 17 and loop 20.

Front wall 12 of the housing has four code buttons 21,22,23 and 24 and a closure means 25 by which the front wall may be locked into the housing. Front wall 12 is marked with an arrow 26 which should be vertical when the alarm is fixed to a bicycle or other object. When arrow 26 is vertical, the motion detector wire 17 is also vertical and out of contact with loop 20.

The housing carries a secure fixing strap 27 attached at each end to a side wall 28 of the housing. The strap may be of metal or reinforced textile for example. The fixing strap 27 and rear wall 28A of the housing, which latter is of concave form, define a passageway 29 through which the, e.g. bicycle frame, may be attached.

Figure 4 shows how the electronic control means may be programmed to monitor and activate the alarm.

A four key code entry pad 30 corresponding to the four code buttons of Figure 1 enables a four digit code to be transmitted to entry control circuit 31. If the correct code is transmitted, the alarm is primed. Similarly, if the correct code is transmitted to the primed alarm, the alarm is then deactivated. The integrated control circuit or chip 35 on receipt of the correct code activates logical OR gate 32 to maintain the primed condition. The control means are programmed to allow three attempts to transmit the correct code. Thus at the commencement of a fourth attempt, i.e. on pressing a code button for the thirteenth time, the counter circuit 33A activates logical OR gate 33 to trigger the sound generator 34.

If the alarm has been correctly primed, any movement of the object to which it is attached will complete the electrical circuit between wire 17 and contact 20 of motion detector 16.

The control circuit 35A then activates gate 32 to pass current to the sound generator 34 to sound the alarm. Circuit 35 is programmed to stop the sounder after an initial sound for a period of 20 seconds, after which, if movement continues, which would cause continued making and breaking of the electrical circuit between wire 17 and contact 20, the gate 33 continues to send current to the sound generator. The circuit is broken after 60 seconds by control circuit 36 and closed again after a 20 second delay. This cycle continues until the alarm is deactivated by punching in the appropriate code at entry pad 30.

Thus the circuitry of Figure 4 covers four conditions of the alarm: a) the alarm is primed. Three inputs from the motion detector 16 give a warning tone to deactivate when motion stops after 20 seconds; b) priming of the alarm during which three attempts to enter the four digit code combination are allowed. A thirteenth digit entry will sound the alarm; c) the alarm is primed. Three inputs from motion detector 16 cause the alarm to sound. This can then be cancelled by condition A, i.e. keying in of the correct de activation code, and d) covers all other conditions which are re-set and repeated after 20 seconds.

Figure 5 shows the detailed circuit diagram and the following Table lists the parts used.

TABLE PARTS LIST FOR: ALARM UNIT

PART TYPE OUTLINE SUPPLIER PART NO.

1C1 4584B 6*SCHMITT TRIGGER DIL14 RS 641-415 IC2 4071B 4*2 UP OR GATE DIL14 RS 308-433 IC3 4013B 2*D-TYPE F/FLOP DIL14 RS 306-550 IC4 4048B PHASE LOCKED LOOP DIL16 RS 306-645 IC5 4066B 4*BILATERAL SWITCH DIL14 RS 640-620 IC6 4520B 2*BINARY COUNTER DIL16 RS 309-802 IC7 4538B 2*MONO MULTIVIBRATOR DIL16 RS 309-852 IC8 UA3730 SECURITY LOCK DIL18 MAPLIN UM98G C1 0.1 UF 63V WIMA CAPACITOR CAPR4 RS 114-834 C2 10UF 16V ELECTROLYTIC RADIAL CAPR4D4E RS 103-957 C3 0.1 UF 63V WIMA CAPACITOR CAPR4 RS 114-834 C4 0.1 UF 63V WIMA CAPACITOR CAPR4 RS 114-834 C5 0.1UF 63V WIMA CAPACITOR CAPR4 RS 114-834 C6 47UF 16V ELECTROLYTIC RADIAL CAPR4D8E RS 103-979 C7 100UF 16V ELECTROLYTIC RADIAL CAPR4D8E RS 104-477 C8 10UF 16V ELECTROLYTIC RADIAL CAPR4D4E RS 103-957 C9 0.1 UF 63V WIMA CAPACITOR CAPR4 RS 114-834 C10 1ONF 63V WIMA CAPACITOR CAPR4 RS C11 lOUF 16V ELECTROYLTIC RADIAL CAPR4D4E RS 103-957 C12 0.1UF 63V WIMA CAPACITOR CAPR4 RS 114-834 C13 0.1uf 63V WIMA CAPACITOR CAPR4 RS 114-834 C14 10UF 16V ELECTROLYTIC RADIAL CAPR4D4E RS 103-957 C15 0.1UF 63V WIMA CAPACITOR CAPR4 RS 114-834 C16 0.1UF 63V WIMA CAPACITOR CAPR4 RS 114-834 C17 0.47UF 63V ELECTROLYTIC RADIAL CAPR4D4E RS 104-045 C18 0.lUF 63V WIMA CAPACITOR CAPR4 RS 114-834 C19 10UF 16V ELECTROLYTIC RADIAL CAPR4D4E RS 103-957 C20 1UF 63V ELECTROLYTIC RADIAL CAPR4D4E RS 104-051 C21 0.1 UF 63V WIMA CAPACITOR CAPR4 RS 114-834 C22 0.1 UF 63V WIMA CAPACITOR CAPR4 RS 114-834 C23 220PF CERAM PLATE LOW K CAPR4 RS 126-966 C24 0.1 UF 63V WIMA CAPACITOR CAPR4 RS 114-834 C25 330UF 35V ELECTROLYTIC RADIAL CAPR4D8E RS 107-434 C26 10UF 16V ELECTROLYTIC RADIAL CAPR4D4E RS 103-957 R1 100K 1/4 W CiF 5% RESISTOR RESA08 RS 131-491 R2 1M 1/4 W C/F 5% RESISTOR RESA08 RS 131-615 R3 100K 1/4 W CiF 5% RESISTOR RESA08 RS 131-491 R4 100K 1/4 W CIF 5% RESISTOR RESA08 RS 131-491 R5 270K 1/4 W CIF 5% RESISTOR RESA08 RS 131-542 R6 10R 1/4 W CJF 5% RESISTOR RESA08 RS 131-019 R7 4K7 1/4 W C/F 5% RESISTOR RESA08 RS 131-328 R8 100K 114 W CiF 5% RESISTOR RESA08 RS 131-491 R9 4K7 114 W CiF 5% RESISTOR RESA08 RS 131-328 RIO 150K 1/4 W C/F 5% RESISTOR RESA08 RS 131-514 R11 100K 1/4 W C/F 5% RESISTOR RESA08 RS 131-491 R12 390K 1/4 W C/F 5% RESISTOR RESA08 RS 131-564 R13 56K 1/4 W C/F 5% RESISTOR RESA08 RS 131-463 R14 VALVE TO SET MAX Hz (VALVE TO BE 10K TO 1M) RS R15 100K 1/4 W C/F 5% RESISTOR RESA08 RS 131-491 R16 33K 114 W C/F 5% RESISTOR RESA08 RS 131-435 R17 100K 1/4 W C/F 5% RESISTOR RESA08 RS 131-491 R18 100K 1/4 W C/F 5% RESISTOR RESA08 RS 131-491 R19 100K 1/4 W C/F 5% RESISTOR RESA08 RS 131-491 R20 VALVE TO @ SET BASE Hz (VALVE TO BE 10K TO 1M RS R21 100K 1/4 W C/F 5% RESISTOR RESA08 RS 131-491

PARr TYPE OUTLINE | SUPPLIER PART NO.

R22 150K 1/4 W CiF 5% RESISTOR RESA08 | RS 131-514 R23 100K 1/4 W CiF 5% RESISTOR RESA08 | RS 131-491 R24 100K W C/F 5% RESISTOR RESA08 RS 131-491 R25 100K W C/F 5% RESISTOR RESA08 RS 131-491 R26 100K W C/F 5% RESISTOR RESA08 RS 131-491 R27 100K W C/F 5% RESISTOR RESA08 | RS 131-491 R28 100K W C/F 5% RESISTOR RESA08 RS 131-491 R29 100K W C/F 5% RESISTOR RESA08 RS 131-491 R30 100K W CiF 5% RESISTOR RESA08 RS 131-491 R31 2M2 W C/F 5% RESISTOR RESA08 RS 135-623 R32 100K W C/F 5% RESISTOR RESA08 RS 131-491 R33 100K W C/F 5% RESISTOR RESA08 RS 131-491 R34 15K 1% 1/4 W M/F 1% RESISTOR RESA08 RS 148-770 R35 10K W C/F 5% RESISTOR RESA08 RS 131-378 R36 100K W C/F 5% RESISTOR RESA08 RS 131-491 R37 100K 1/4 W C/F 5% RESISTOR RESAO8 RS 131-491 R38 10K W C/F 5% RESISTOR RESA08 RS 131-378 R39 100K W C/F 5% RESISTOR RESA08 RS 131-491 TR1 BC182 NPN TRANSISTOR T092+PAD FEC BC182 TR2 BC182 NPN TRANSISTOR T092+PAD FEC BC182 TR3 BC212 PNP TRANSISTOR T092+ PAD FEC BC212 TR4 BC182 NPN TRANSISTOR T092+PAD FEC BC182 TR5 BC182 NPN TRANSISTOR T092+PAD FEC BC182 D1 1N4002 DIODE D041 RS 261-154 D2 LED 3MM RED LOW CURRENT LED 3MM RS 588-386 D3 0A200 0.3V GERMANIUM D035 D4 1N4148 DIODE D035 RS 271-606 D5 1N4148 DIODE D035 RS 271-606 D6 1N4148 DIODE D035 RS 271-606 D7 1N4148 DIODE D035 RS 271-606 D8 1N4148 DIODE D035 RS 271-606 D9 1N4148 DIODE D035 RS 271-606 D10 1N4148 DIODE D035 RS 271-606 D11 1N4148 DIODE D035 RS 271-606 D12 1N4148 DIODE D035 RS 271-606 D13 1N4148 DIODE D035 RS 271-606 D14 1N4148 DIODE D035 RS 271-606 D15 1N4148 DIODE D035 RS 271-606 D16 1N4148 DIODE D035 RS 271-606 D17 1N4148 DIODE D035 RS 271-606 TX1 TRLT44 AUDIO TRANSFORMER TRLT44 MAPLIN HX82D PZ1 PIEZO PIEZO BT1 PP3 BATTERY PP3 RS 489-021 SW1 SWITCH PCB N/O SW SW2 SWITCH PCB N/O SW SW3 SWITCH PCB N/O SW SW4 SWITCH PCB N/O SW SW5 SWITCH PCB N/O SW SW6 SWITCH PCB N/O SW SW7 SWITCH MOVEMENT SENSOR SW UJ1 2N6027 PRO UNIJUNCTION T092+PAD FEC 2N6027 Notes 1. The piezo sound generator can be of type and size to be selected for maximum annoyance factor - m range 2.7 to 4k.

2. R14 and R20 are sized to suit the piezo selection and required noise level.

3. R34 is selected to ensure base frequency for K8 timer with capacitor 23.

4. Diode D3 is of low voltage (0.3) to reduce power drain in standby mode.

5. D4/D5 combination pulls voltage up at start to boost system and ensure maximum battery use - even down to low level charge (6v) via transformer TX1.

6. Selector switches are chosen to suit final equipment design.

It will be appreciated that various embodiments may be changed without departing from the scope and spirit of the invention.

For example, the timings of the sound on and off cycles may be changed as desired. The sound alarm could be in the form of a speech synthesiser to give out a message rather than just a loud noise. The battery may be recharged by connection via a cable to a wheel of the bicycle.

Claims

CLAIMS 1. An alarm for attachment to a movable object, the alarm comprising a housing containing a motion detector, electronic control means, an electrical power source, and a sound generator, priming means being provided on an exterior wall of the housing, whereby when the alarm is primed, movement of the object causes closing of an electrical circuit by the motion detector whereby the control means activates the sound generator.
2. An alarm according to Claim 1, in which the electronic control means are arranged to activate the sound generator intermittently when the system is activated.
3. An alarm according to Claim 2, in which initial movement of the object causes a brief initial sound alarm and the alarm is deactivated if no further movement takes place within a predetermined time.
4. An alarm according to Claim 1, 2 or 3, in which the priming means is a security code entered by pressing buttons on the housing.
5. An alarm according to any preceding Claim, in which the electronic control means accepts the same code for priming and deactivating the alarm.
6. An alarm according to any preceding Claim, in which the motion detector is a suspended wire and movement of the object causes rotation of the wire to close the electrical circuit.
7. An alarm according to any preceding Claim, in which the sound generator is of the piezoelectric crystal microphone type.
8. An alarm according to any preceding Claim, in which the housing is a lightweight plastics or rubber moulding.
9. An alarm according to any preceding Claim, in which the housing is recessed to conform closely to a tubular frame portion of a bicycle.
10. An alarm according to any preceding Claim, in which the housing is marked to show a required vertical positioning when attached to the object.
11. An alarm according to any preceding Claim, in which the control means are programmed to allow a predetermined number of attempts to prime and to deactivate the alarm.
12. An alarm according to any preceding Claim, in which the sound generator produces synthesised speech.
13. An alarm according to any preceding Claim, in which the power source is a rechargeable battery.
14. An alarm for attachment to a movable object substantially as hereinbefore described with reference to and as shown in the accompanying drawings.