Patent Abstract:
A noise-producing device comprises a body ( 12 ) having a clamp ( 24 ) for mounting the body to a frame member of a bicycle or other motorless vehicle with spoked wheels. The device includes a card holder ( 15 ) for securing a resiliently flexible card ( 14 ) to the body such hat the card extends freely outwardly from the body. A resonant chamber ( 18 ) in the body amplifies the sound produced by the intermittent interaction of the free end of the card with the spokes of the bicycle wheel.

Full Description:
FIELD OF THE INVENTION 
   The present invention relates to devices for producing noise. The invention has particular application in devices for producing noise when mounted on an vehicle without an engine, such as a bicycle, tricycle, or motorless scooter. 
   BACKGROUND OF THE INVENTION 
   Children using bicycles will often add a simple device for producing noise to simulate the sound of a combustion engine. This may be done by attaching a playing card to a frame member of the bicycle, usually the rear stay, with a clip such as a clothes peg so that the card projects between the spokes. When the wheels turn, the spokes rapidly strike the card producing a noise which somewhat approximates that of an engine. 
   Various custom-designed devices have been proposed to improve on such home made arrangements. Examples of such devices are described in U.S. Pat. Nos. 3,716,944, 3,905,151, 4,701,149, 4,875,885, 5,226,846, 5,611,558 and U.S. Pat. No. 6,394,875. 
   These devices suffer from various shortcomings which the present invention is intended to address. 
   SUMMARY OF THE INVENTION 
   The invention provides a noise-producing device comprising a body having means for mounting the body to a frame member of a bicycle, a card holder for securing a resiliently flexible card-like member (“card”) to the body such that the card extends freely outwardly from the body, and a resonant chamber in the body for amplifying the sound produced by the intermittent interaction of the free end of the card with a bicycle wheel. 
   The term “bicycle” as used herein is intended to encompass bicycles, tricycles, scooters and other motorless vehicles having wheels of a type which when rotated will vibrate a card to produce a noise, such as spoked wheels. 
   Preferably the device includes a hollow component in the form of a simulated exhaust removably mountable on the body with its interior in communication with the resonant chamber for further amplifying the sound produced by the card. 
   The means for mounting the body to a frame member of a bicycle may comprise an open channel extending into the body in which a frame member can be received. In such case the open channel may comprise a pair of side walls and a base for receiving the frame member, the device further including a fastening means to draw the side walls together and thereby grip the frame member in the base. 
   Preferably the card holder comprises a slot which is adapted to retain the card by its edges so that a majority of the surface of the card facing away from the body is exposed. 
   Further, the resonant chamber is preferably open to the surface of the card facing towards the body. 
   The invention further comprises the combination of a device as specified above and a resiliently flexible card-like member mounted in the card holder. 

   
     BRIEF DESCRIPTION OF DRAWINGS 
     The invention will now be illustrated by the following descriptions of embodiments thereof given by way of example only with reference to the accompanying drawings, in which: 
       FIG. 1  is a perspective view from above of a noise-producing device according to a first embodiment of the invention. 
       FIG. 2  is a perspective view from below of the device of  FIG. 1 . 
       FIG. 3  is a top plan view of the device of  FIG. 1 . 
       FIG. 4  is a bottom plan view of the device of  FIG. 1 . 
       FIG. 5  is a side view of the device of  FIG. 1 . 
       FIG. 6  is a front elevation of the device of  FIG. 1 . 
       FIG. 7  is a rear elevation of the device of  FIG. 1 . 
       FIG. 8  shows the device of  FIG. 1  when mounted on a bicycle. 
       FIG. 9  is a perspective view from below of a noise-producing device according to a second embodiment of the invention. 
       FIG. 10  is a perspective view from above of the device of  FIG. 9 . 
       FIG. 11  is a perspective view from above of the main body of the device of  FIG. 9 , omitting the card, base liner, simulated exhaust and other attachments. 
       FIG. 12  is a perspective view of the card used in the device of  FIG. 11 . 
       FIGS. 13 and 14  are perspective views of the simulated exhaust used with the device of  FIG. 11 . 
       FIG. 15  is a perspective view of an apertured reflector fitted to the simulated exhaust of  FIGS. 13 and 14 . 
       FIG. 16  is a perspective view of a base liner used in the device of  FIG. 11 . 
   

   DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     FIGS. 1 to 7  together show a first embodiment of noise-producing device according to the invention. The device  10  comprises a body  12  into which a resiliently flexible card-like member  14  (“card”) is mounted. The card  14  may be replaceable or it may be fixed in place at the time of assembly of the device by the user. The body  12  is moulded of a semi-rigid plastics material and the card  14  is made, for example, of polypropylene. 
   The card  14  is retained by its edges in a slot  15  which snugly receives and surrounds one end of the card on three sides so that a free end  16  of the card extends from the body  12  and a majority of the surface of the card facing away from the body  12  is exposed. The free end  16 , when it protrudes into the spokes of a rotating spokes wheel, is repeatedly urged forward by successive spokes before snapping back towards its usual flat shape. This repetitive motion gives rise to an engine-like noise. In the present embodiment the card  14  is replaceable in the body  12  and is secured in place by a small allen bolt  11  which engages the end of the card within the slot  15 . 
   A resonant chamber  18 , in the form of a bore having a roughly triangular cross-section and open at each opposite end  20 , extends through the body  12  in a direction transverse to the direction in which the card  14  extends from the body  12 . The chamber  18  amplifies the noise transmitted from the card to the body providing a more realistic, fuller sound. A pair of end caps (not shown) may be provided to seal the open chamber ends  20  to vary the resonant characteristics of the chamber. 
   The device is mounted on the frame of a bicycle  30  (see also  FIG. 8 ) by means of an open channel  22  having opposed sidewalls  24  and a base  26  which is shaped to receive a frame member such as a rear stay  28  of bicycle  30 . The channel  22  is substantially parallel to the resonant chamber  18 . 
   A castellated compressible material  32  lines the base  26  to improve the grip of the mounting. A pair of alien bolts  34  each extends through a pair of threaded holes  36  in opposite sidewalls  24  to allow the sidewalls to be drawn together when a frame member, such as the rear stay  28 , is engaged in the base  26 . Tightening or loosening the allen bolts increases or relaxes the grip of the base on the frame member. When the allen bolts are removed, the device can be engaged or disengaged from the frame member. 
   When the device is mounted on a bicycle  30  as shown in  FIG. 8 , a display area  38  having a flat surface faces generally outward (i.e. away from the wheel). This display area provides a surface for receiving printed indicia or adhesive labels, to provide branding or advertising space which is readily visible on the device. Alternatively, a brand name or logo can be moulded in relief on the display area  38 , as an integral part of the body  12 , as shown  FIGS. 9 and 10  of the second embodiment to be described. Due to the noise produced by the device in use, and the natural tendency of the eye to be drawn to a source of noise, the display area  38  is particularly prominent and therefore valuable. 
     FIGS. 9 to 16  show a device  100  according to a second embodiment of the invention. In  FIGS. 9 to 16 , features and components the same or functionally equivalent to those shown in  FIGS. 1 to 8  are given the same reference numerals will not be further described. The following description will therefore concentrate on the differences between the first and second embodiments. 
   The primary difference is that in the device  100  the resonant chamber  18  is only open at one end, i.e. the end  20  seen in  FIG. 11 , and that in use a hollow simulated exhaust  40  ( FIGS. 9 ,  10 ,  13  and  14 ) is removably mounted on the body  12  with its interior in communication with the chamber  18  via the open end  20 . The simulated exhaust  40  has a generally funnel-like shape with an open, relatively narrow, front end  42  and an open, relatively wide, rear end  44 , the main body of the exhaust being in the form of a hollow cylinder  46 . The narrow front end  42  of the exhaust  40  has an external cross-section complementary to the interior cross section of the open end  20  of the bore  18 , and the exhaust  40  is fitted to the body  12  by inserting the end  42  into the open end  20  as seen in  FIGS. 9 and 10 . The simulated exhaust  40  acts like a megaphone or loudspeaker to further amplify the sound produced by the card  14 . A circular safety reflector  48 ,  FIG. 15 , may be fitted across the wide rear end  44  of the exhaust  40 . This has a plurality of apertures  50  to allow the sound to escape from the simulated exhaust. 
   In this embodiment, too, the resonant chamber  18  has a top opening  52  within the area defined by the three sides of the slot  15  so that, in use, the chamber  18  is open to the surface of the card  14  facing towards the body  12 . This enhances the transmission of sound from the card to the resonant chamber  18 . Also, the card  14  has a tab  17  which projects out of the slot  15  when the card is fully inserted in the body  12 , the tab  17  facilitating the user to insert and remove the card. 
   The card  14  and simulated exhaust  40  are retained in position on the body by a removable pin  54 , shown in dashed lines in  FIG. 10 , which passes down into the chamber  18  through a hole  56  ( FIG. 11 ) in the body  12 . The pin  54  engages a semi-circular recess  58  ( FIG. 12 ) in the card  14  to prevent its withdrawal from the body  12 , and enters a groove  60  in the front end  42  of the exhaust to likewise prevent removal of the exhaust from the body  12 . The pin  54  itself is prevented from coming out of the hole  56  by a strap  62 , the pin  62  being integral with one end of the strap  62  and the other end of the strap being formed with a hole which is engaged by one of the bolts  34 . 
   In this embodiment the castellated material  32  is in the form of a replaceable liner of a semi-rigid plastics material,  FIG. 16 , so that bicycle frame members of different diameters can be accommodated by the use of liners  32  of different radial dimensions. Alternatively, a set of nested liners  32  can be provided, one or more being used according to the diameter of the frame member. 
   The moulded body  12  of the device  100  also has a number of features designed to assist cooling of the device in use and/or to assist flexing of the body to conform to different bicycle frame members. Slots  64  ( FIG. 11 ) allow the body  12  to bend along a longitudinal axis at this point to clamp on to the bicycle frame member when the bolts  34  are tightened. Longitudinal holes  66  are formed in the body  12  above and below the slots  64  to provide mounting points for future items to be fitted to the body  12 , as well as providing a weight and material saving and increasing the total surface area of the body  12  to assist its cooling in use. Recesses  68  ( FIG. 9 ) running transversely of the channel  22  through the sidewalls  24  allow a slight bending of the body  12  in the longitudinal direction to accommodate any slight curvature in the bicycle frame member, as well as reducing weight/material usage and increasing the surface area of the body for cooling. Finally, a slot  70  in the side of the body  12  again reduces weight/material usage and increases the surface area of the body for cooling. 
   The invention is not limited to the foregoing examples which may be varied without departing from the scope of the claimed invention.

Technology Classification (CPC): 1