Security alarm

Abstract

A motorcycle security alarm comprises a mounting 1 to a motorcycle; one or more alarm units 9 each comprising a housing 15 having an aperture 18, a motion sensing component comprising an audio element

Description

This invention relates to a security alarm for a two wheeled vehicle, particularly but not exclusively for a motorcycle in which a registration plate is mounted adjacent the rear wheel transversely to the direction of travel. The invention may also find application for use with other vehicles having two or more wheels, for example, a motor scooter or tricycle. The vehicles to which this invention relates are referred to in the specification for brevity as motorcycles. A disadvantage of existing motorcycles is that they may not be fitted with alarms when manufactured. Security padlocks may be heavy, cumbersome and easily observed by a would-be thief, making them difficult to transport when not in use and easily visible, facilitating removal using a cutting tool. UK patents 2585239 and 2615385 disclose a security alarm for a vehicle. According to the present invention, a motorcycle security alarm comprises: a mounting having: one or more fasteners configured to secure the alarm to a motor cycle; one or more alarm units mounted on the mounting; the or each alarm unit comprising a housing having an aperture communicating between the interior and exterior of the housing; a motion sensing component comprising an audio element, the motion sensing component being located within an interior space of the housing adjacent the aperture of the housing; the motion sensing component being configured to detect movement of the housing and to generate an audible alarm signal from the audio element in response to said movement, the alarm signal being audible from the aperture; the alarm unit including a sound reflecting member having a sound reflecting or refracting surface; the member comprising a body extending between first and second portions, the first portion secured to the housing of the alarm unit, the second portion located in spaced relation to the housing, and configured so that the housing and the body between the first and second ends define a cavity, the cavity having a dimension between the body and housing the dimension increasing from the first portion to the second portion; the member overlying the aperture so that the aperture is located in the cavity with the sound reflecting or refracting surface facing toward the aperture, so that the audible signal emitted from the aperture is reflected or refracted from the member. The member may be elongate so that the portions comprise first and second ends of the member. The member may comprise an elongate strip, for example a parallel sided sheet. In advantageous embodiments the member is composed of resilient material, so that the second portion or end may be resiliently deflected towards or away from the housing. This deflection may decrease or increase the dimension of the cavity between the surfaces of the housing and member. The aperture may be located in the cavity adjacent the second portion or second end of the member. In a preferred embodiment two or more, preferably two alarm units are may be provided. In a further preferred embodiment, two alarm units are provided, the units being mounted in spaced relation on the mounting; the units being configured to face forwardly from the sound refracting surface with respect to a direction travel in use, when mounted on a motorcycle. The mounting may be adapted to be secured in use to a forward-facing surface of a rear number plate of a motorcycle. The sound refracting surface may be arranged to refract and / or reflect sound emitted from the alarm units towards the mounting. The surface may comprise the body of the mounting or may be secured to the mounting. 2 The mounting may be a plate, for example a plate having a flat or curved surface which serves as a sound refracting surface. The surface may be smooth or polished to improve efficient refraction of the audible alarm signal. Alternatively, the mounting may comprise a frame or one or more support members to which a plate or other refracting surface is attached. The alarm unit may be constructed as disclosed in my GB2585239 or GB 2615385 the disclosures of which are incorporated into this specification by reference for all purposes. The two alarm units may be located on opposite sides of and equidistant from a centre line of the mounting, the mounting being adapted to be secured in use to the forwardly facing surface of a rear motorcycle numberplate. In such an arrangement, the alarm unit may be wholly, or partially concealed behind the numberplate and conveniently situated to permit efficient refraction of the audible alarm signal. In such an arrangement, the alarm units may be wholly or partially concealed behind the numberplate. Installation or replacement of the security alarm is a simple process, which does not damage the body panels or other more expensive components of a motorcycle. In a preferred embodiment, each alarm unit has sloping sides. The transverse dimension of the unit preferably decreases from a base where it is secured to the mounting or sound refracting surface, towards the apex of the unit arranged to face towards the front in the direction of travel. This arrangement improves the aerodynamic properties of the alarm and reduces wind resistance of a numberplate to which it is attached. Equidistant spacing of the two alarm units from the centreline of the security alarm and of the numberplate to which it is attached, provides an improved aerodynamic property of the numberplate. The space between the alarm units provides a channel to conduct an air flow created by rotation of the rear wheel. This provides a self-cleaning function and reduces turbulence and consequent instability of the motorcycle in use. The motion sensing component may be a vibration alarm sensor or a tremor alarm sensor. The generated alarm signal may be one or both of an audio alarm or signal to a mobile phone or other receiver. The motion sensing component may include a GPS receiver. The motion sensing component may be turned on and off using an actuator button. The motion sensing component may be adjusted to a predetermined sensitivity or tolerance value which, when exceeded due to movement of the housing, generates the alarm signal. Alternatively, or in addition to, the motion sensing component may be remotely turned on or off and / or adjusted to a predetermined sensitivity or tolerance using a remote control. Alternatively, or in addition to, the motion sensing component may be remotely turned on or off and / or adjusted to a predetermined sensitivity or tolerance via a mobile device, for example a phone. The security alarm of the present invention provides many advantages. The motion sensor may perform several functions. The sound from the alarm is reflected or refracted so that it is emitted in multiple directions, making it more difficult for a would-be thief to muffle the alarm signal. The increasing dimension of the cavity between the housing and member may provide acoustic amplification and increase the angular distribution of the alarm signal. Flexing of the unattached portion of the member may occur in use due to vibration of the motorcycle as it is driven, for example over an uneven road surface, or in the event of an impact with a foreign body, for example a stone thrown up from the road’s surface by the motorcycle wheel. Vibration of the unattached portion may serve to dislodge any debris which may have adhered to the unit during use. The flexible portion of the member also provides protection against damage due to impacts, for example from stones during use. The member may also cover the aperture, preventing ingress of debris and water which may be thrown up from the road in use. The invention is further described by means of example, but not in any limitative sense with reference to the accompanying drawings, of which: Figure lisa perspective view of a security alarm according to the invention; Figures 2 to 5 are plan and elevation views of the alarm unit of Figure 1; and Figure 6 is an enlarged cross-section of the alarm unit. The Figures show a security alarm in accordance with this invention. A mounting comprises a rectangular plate (1) having an array of slots (2), (3), (4) extending through the plate to facilitate securely mounting of the alarm to the forwardly facing surface of a motorcycle rear numberplate (not shown). The mounting is secured using nuts and bolts (5), (6), (7) or other fasteners as convenient. Locking nuts may be employed. Two alarm units (9), (10) are mounted on the mounting plate (1). The units are equally spaced on either side of a centreline of the mounting plate. A fixing slot (2) is located on the centreline to receive a bolt passing through the centre of the number plate. The surface (8) of the plate (1) is polished to improve the refraction and / or reflection of sound emitted by the units (9), (10). Each alarm unit (9), (10) comprises a generally rectangular housing having sloping sides (12), 13), and long and short upper surfaces (14), (15), (16), (17). Apertures (18), (19) in the short upper surfaces (14), (15), (16), (17) communicate with the interior of the housing to permit an audible alarm signal to be emitted from each alarm unit. Members (20), (21), (22), (23) extend over and cover respective larger surfaces (14), and smaller surfaces (15) of the alarm units. Each member (20), (21) comprises a larger portion (20), (21) secured to a respective larger upper surface (12), (14) of the housing. A smaller portion (22), (23) of each member is resiliently attached to the respective larger portion. The smaller portions may flex about a hinge line (24), (25) extending across the width of the unit between the long and short upper surfaces. The members (20), (22), (21), (23) are in the form of generally elongate rectangular strips configured to overlie the surfaces, e.g. (14), (15) of the respective unit. A portion of the member, for example the shorter portion, overlies the aperture (16), (17) in spaced relation to the aperture to form a cavity which permits passage of an alarm signal from the alarm unit through the aperture to the exterior of the unit. The unattached portion, typically the shorter portion, and the underlying body of the unit form a cavity (27), (28). The dimension of the cavity (27), (28) increases from a minimum value at the line of contact with the larger portion to a maximum value at the end of the smaller portion remote from the line of contact. The increase in depth of the cavity provides acoustic amplification of the signal in use.

Claims

1. A motorcycle security alarm comprising a mounting having: one or more fasteners configured to secure the alarm to a motor cycle;one or more alarm units mounted on the mounting;the or each alarm unit comprising a housing having an aperture communicating between the interior and exterior of the housing;a motion sensing component comprising an audio element, the motion sensing component being located within an interior space of the housing adjacent the aperture of the housing;the motion sensing component being configured to detect movement of the housing and to generate an audible alarm signal from the audio element in response to said movement, the alarm signal being audible from the aperture;the alarm unit including a sound reflecting member having a sound reflecting or refracting surface;the member comprising a body extending between first and second portions, the first portion secured to the housing of the alarm unit, the second portion located in spaced relation to the housing, and configured so that the housing and the body between the first and second ends define a cavity, the cavity having a dimension between the body and housing the dimension increasing from the first portion to the second portion;the member overlying the aperture so that the aperture is located in the cavity with the sound reflecting or refracting surface facing toward the aperture, so that the audible signal emitted from the aperture is reflected or refracted from the member.

2. An alarm as claimed in claim 1 wherein the member is elongate with the portions comprising first and second ends of the member.

3. An alarm as claimed in claim 1 or 2 wherein the member comprises an elongate strip.

4. An alarm as claimed in claim 3 wherein the member comprises a parallel sided sheet.

5. An alarm as claimed in any preceding claim wherein the member is composed of resilient material.

6. An alarm as claimed in claim 5 wherein deflection of the resilient material increases or decreases the dimension of the cavity between the surfaces of the housing and member.

7. An alarm as claimed in any preceding claim wherein the aperture is located in the cavity adjacent the second portion of the member.

8. A security alarm as claimed in any preceding claim comprising two alarm units.

9. A security alarm in claimed in claim 8 wherein the alarm units are mounted inspaced relation on the mounting, the units being configured to face forwardly from the said mounting plate with respect to a direction of travel in use when mounted on a motorcycle.

10. A security alarm as claimed in any preceding claim wherein the mounting is adapted to be secured in use to a forward-facing surface of a rear numberplate of a motorcycle.

11. A security alarm as claimed in any preceding claim wherein the mounting comprises a sound refracting surface.

12. A security alarm as claimed in any preceding claim wherein the mounting is a plate having a flat or curved surface.

13. A security alarm as claimed in any preceding claim wherein the two alarm units are located on opposite sides of and equidistant from a centreline of the mounting.

14. A security alarm as claimed in any preceding claim wherein each alarm unit has sloping sides.

15. A security alarm as claimed in claim 14 wherein the transverse dimension of the unit decreases from a base where it is secured to the mounting towards the apex of the unit.

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