US3286393A

US3286393A - Toy sound device adapted to actuate a resonator by repetitive shock excitation

Info

Publication number: US3286393A
Application number: US448712A
Authority: US
Inventors: John W Ryan
Original assignee: Mattel Inc
Current assignee: Mattel Inc
Priority date: 1965-04-16
Filing date: 1965-04-16
Publication date: 1966-11-22
Anticipated expiration: 1983-11-22
Also published as: DE1939548U; GB1087206A; NL6512710A

Description

Nov. 22, 1966 J. w. RYAN TOY SOUND DEVICE ADAPTED TO ACTUATE A RESONATOR BY REPETITIVE SHOCK EXCITATION 4 Sheets-Sheet 1 Filed April 16, 1965 INVENTOR. 74/? W F /A flrfa/wvfflf 1965 J. w. RYAN 3,286,393

TOY SOUND DEVICE ADAPTED To ACTUATE A RESONATOR BY REPETITIVE SHOCK EXCITATION Filed April 16, 1965 4 Sheets-Sheet 2 INVENTOR.

Nov. 22, 1966 J. w. RYAN 8 TOY SOUND DEVICE ADAPTED TO ACTUATE A RESONATOR BY REPETITIVE SHOCK EXCITATION 4 Sheets-Sheet Filed April 16, 1965 5 R W W @3 m M m k\ Wm W n M W QMMQ I M \w qwww QR w Nov. 22, 1966 J w. RYAN 3,286,393

TOY SOUND DEVICE ADAPTED TO ACTUATE A RESONATOR BY REPE'I'ITIVE SHOCK EXCITATION Filed April 16, 1965 4 Sheets-Sheet 4 ,Tmw a/ Fri/v %%Q MXLZ United States Patent 3,286,393 TOY SOUNDDEVICE ADAPTED TO ACTUATE A IEg13NATOR BY'REPETITIVE SHOCK EXCITA- John W. Ryan, Bel Air, Califi, assignor to Mattel, Inc., Hawthorne, Calif., a corporation of California Filed Apr. 16, 19 65, Ser. No. 448,712 Claims. (Cl. 46-111) This application is a continuation-in-part of a co-pending application filed October 2, 1963 under Serial No. 313,285 by the applicant herein, now Patent No. 3,236,008. In general, the present invention relates to a device for simulating motor sounds. More specifically, the present invention relates to a device adapted to emit when operated sounds closely corresponding to the sounds of an internal combustion motor.

In said co-pending application it was noted that, in the past, there have been many toy vehicles having devices mounted thereon to simulate a motor sound. The conventional device which has been employed involves a reed fixed at one end and extending free at another end but engaged with a rotating gear wheel so that the reed is vibrated to emit sounds. However, such prior art motor sound devices customarily emitted very highpitched uniform sounds which were far removed from the ordinary internal combustion motor sound of vehicles such as trucks and cars whose motor sound is customarily low-pitched and usually includes a cyclic variation of sound. Furthermore, the usual prior art motor sound device involved a substantial period of contact between the portion of the device emitting the sound and the portion of the device actuating the sound emitter. Thus, a considerable portion of the vibration energy was lost and the resulting sound device was relatively inefficient. Also, prior art motor sound devices usually utilized direct contact between the sound emitter and the actuator for the sound emitter, so that stresses and strains were put on the sound emitter which did not contribute to the volume of the sound being emitted. Consequently, the usual prior art device had a relatively short life because of the intense strains and stresses being put on the sound emitter apart from the function of emitting sound.

Many of these prior art motor sound devices include resonator means which is coupled to a driving means in such a manner that the resonator means is excited for a fixed period.

The special analysis of the sound produced by a typical automobile engine indicates that, for optimum reproduction, the maximum energy contained in the spectrum should be below approximately 2500 c.p.s. However, in an automobile engine and in a system for simulating motor sounds, the frequency of the sound alone is insufficient to define a reasonablesimulation of a motor sound.

The spectrum should be one in which a broad sweep of frequencies is indiscriminately produced without sharply defined and well-separated peaks. Sharply defined and well separated peaks produce a musical sound like a lowpitched horn or bell. When such peaks do not exist, a noise results and, if the noise is in a relatively low frequency range, it simulates a motor sound.

The devices for simulating motor sounds of the present invention include systems which are shock-excited with a lot of resonance. This shock-exciting is done repetitively, without necessarily having a fixed period. The exciting of the system is done in a free mode. This means the system is simply hit; it is not rigidly coupled to a driving means. Thus, the present invention primarily relates to vibratile systems in which there is not a rigid coupling and direct drive of the resonator.

Vibratile systems which are capable of producing sound within the frequency ranges which characterize the noise low 2,500 c.p.s.

3,286,393 Patented Nov. 22, 1966 "ice produced by internal combustion engines may, within broad limits, be made of many different types of materials whether a single compound, such as polyethylene, or an extremely complex mixture of compounds, such as cardboard. The material may be homogeneous, laminate, or randomly discontinuous, such as chipboard. Also, the material may be solid, porous or of varying density and cross section, such as a woven or pressed fiber structure like fiberboard.

Such vibratile systems may also be made with almost any geometry. For example, a cone, a plane disc and a cup with substantially cylindrical side walls may be employed. These changes in geometry have a marked effect on the resonance characteristics of the system. The same mass of the same material reacts differently acoustically if it is shaped as a cone or cup rather than as a flat disc.

Similarly, the same object will react quite differently acoustically if it is mounted differently. A compliant mounting, in which the object is held loosely and flexibly, will cause it to have different resonance characteristics from a mounting in which it is held rigidly at some one point.

The natural or resonant frequency of a vibratile system is the basic frequency at which it resonates in response to a shock excitation. Although it is difficult to measure this with great precision, it is a characteristic of the systern and usually can be discerned on a spectral analysis of the sound produced by the system as the lowest-frequency substantial peak produced by the system. For example, the spectral analysis of certain toy motor unit cones show a number of peaks, with the last major peak in the vicinity of 2,500 c.p.s. Thus the bulk of the acoustic energy produced in simulation of a motor sound should be be- The natural or resonant frequency of that same cone, however, is about 250 or 350 cycles. Repeated shock excitation of a vibratile system thus may produce the bulk of the energy at frequencies well above the natural or resonant frequency of the particular resonator employed.

The characteristics of vibratile systems which are capable of producing motor sounds may be defined in terms of the stiffness of the system. Thenatural or resonant frequency of the system is defined by the equation f l Stifiness 21r Mass Stiffness is measured in dynes per centimeter; mass is measured in grams; and fr provides a numerical value for the natural frequency of the system in cycles per second.

This equation reflects the obvious fact that the same material with the same geometry produces different resonances, as its mass is varied. A small brass bell has a high pitch; a heavy brass bell may have an extremely low pitch. This formula makes it possible to define a physical characteristic of the vibratile systems-their stiffness which is a necessary condition for any system within a range of weights that is practical for toy use (e.g., A gram to grams) which is capable of producing a reasonable simulation of a motor sound. However, this necessary condition is not in and of itself a sufficient condition; it still must be qualified--i.e., the system must be of a size and nature normal and practical for a toy. With such a limitation, the more extreme combinations of characteristics are eliminated (e.g., an extremely tiny disc of very small mass and very high stiffness, which will produce sounds within the proper frequencies, but which will be inaudible or nearly inaudible and may have a more nearly musical distribution of peaks rather than the noise like distribution which is preferred to simulate a motor sound).

A second limiting factor is that the characteristic impedance of the vibratile system is defined by the equation: Z (mass) (stiffness), wherein mass is measured in grams, stiffness in dynes per centimeter, and the imtightly, the mass was determined and the natural frequency was determined. The stiffnesses were then computed and, as can be seen, all the practical simulations of a motor sound fell within the stiffness between approxipedence provides a numerical value in grams per second. 5 mately and The measurement? of the frequencies The impedance is a measure of the efficiency of the sysrecorded In the table e apprellmanens Whleh are tern, i.e., the eifort required to produce sound from it. cufate to the firsedlglt' The 11st shows that praetleal If the impedance is very high, the system is impractically F g of very stlfi metals (such as b1cyc1e bells wlth inefficient. This equation supports the fact that the use Stlflnesses 1n the range of 10 Produced natural of an extremely Stifi system (eg, an ordinary metal bell) 10 nances above 1,000 cycles per second. In order to obtain which is so heavy that its natural frequency is within the system where repemwe sheek'weltatlen Produces a desired range, is impractical for a toy because of the noise wherein the bulk of the nolse 1s below 2,500 c.p.s., great Weight required to attain this and the energy the natural frequency of the resonator should be below quired to excite the system. It is also eliminated because 1,000 Thus steel bells were not satlsfaciory' of the necessary condition that the spectrum produced by 15 extremely g thm dlse of Polyethylene Wlth a such a system be one in which there are not clearly deness below 10 dld predueefa natural frequen cy fined and well separated peaks, producing a musical sound cycles Per second (whleh nllght eoneelvably a rather than a noise motor sound), but such a tmy disc is much too fragile Investigation of these matters has resulted in the conto be plaetleal for a clusion that a stiffness between 10 and 10 dynes per 0 In Y of the foregomg an obleet of the presellt centimeter is the range Within which a practical toy demventlon 1S a toy motor eound devlee adapted F emlt vice to simulate motor sounds can be made. These limits sounds elosely eon'e'spondmg to sounds of an Internal of stiffness, applied to systems weighing between A gram combustlon l and 100 grams, produce natural frequencies (within the oblect P the P f mventlon e e motor limits of practicality discussed above) which are in the 25 souPd deface havlng a Vlbratlle System Whleh 1s shock range preferred to produce a motor sound. The more excleed (1th a lot P resonanceextreme combinations of high mass and low stiffness, and Stlll Q' lf 0f the p lnventlon 1s a motor low mass with high tiff have to b i d For sound device wherein the sound emitter may be protected example, a 100 gram System with a ifi f 101 (which from direct contact with the actuator for the sound emitwould b something lik a very h floppy loose piece ter and thus relieved of unusual stresses and strains. of rubber) is quite impractical, producing a natural fre- A fulfhel of the Pmsent lnven'floll 1S PTOVlde quency of about 1 /2 cycles per second. The extreme a resonator for a y motor Sound Pal/111g a combination of a stiffness of 10 and a weight of gram, Q resonant q l y, a f Whlch 1S f y which would be something like a very tiny disc of hard Stiff to reproduce 1118b frequfllcles, and amplltude plastic, or oft metal produces a frequency which is far capabilities within the material stress limits which Will too high-Well above 5,000 cycles per second. Taking permitproductlon f a high level of low eq y gythe more reasonable combinations, even at the outer limits A Slllll further ob ect of the present invention is to f th g such as a tiff of 10 d a i h f provide a striker means for a toy motor sound device gram (producing a natural reasonance of 50 cycles per which will excite a resonator with a long impulse and second), or a stiffness of 10 and a weight of 100 grams 40 which will produce an output from the resonator having (producing a natural frequency of 155 cycles) the range a spectrum containing a maximum of energy in ire -of 10 to 10 stiffness demonstrates that by using the more quencies 'below about 25 00 c.p.s. stiff systems with greater masses or the less stiff systems Another object of the present invention is to provide a with lesser masses within the ranges of mass and stiffness, thin, compact toy motor sound device which is especially that 10 to 10 dynes per centimeter are the outer limits Suited for mounting between the fender and a wheel of of stiffness which may be utilized effectively in toys to a vehicle and which includes impeller means engageable simulate motor sounds. with said wheel for rotation thereby.

The following chart is a listing of 21 different sorts of Yet another object of the present invention is to provide vibratile systems, ranging from bicycle bells to toy motor a vibratile system for a motor sound device which has a sound cones and flat plates of polyethylene, paper, cardstiffness within the range of approximately 10 to 10 board, styrene,'brass, steel and rubber: dynes per centimeter.

Type of Resonator Dia., Material fr Mass Stiffness inches (c.p.s.) (gm.) (dynes/cm.)

Bell #1 1,850 47 6. 4x10 Bell #2 2, 050 9. 1x10" Bell #3 1,700 23 2. 6X10 Bell #4 1, 400 64 5. 0X10 Engine cone 250 1. 6 4. 0 10 Racer cone 555 1. 1 1. 4x10 Voice unit cone 230 0.9 1. 9X10 .5 mil flat plate, free 3 25 0.1 2. 5x10 .5 mil fiat plate, tight. 3 200 1 1. 6X10 9 mil flat plate, free 3 1.0 8. 3 10 24 mil flat plate, free 3 360 2.8 1.4)(10 6 mil fiat plate, tight" 3 0.8 7.1 10 o 8 P.E 41 4.2 2. 3x10 24 mil fiat plate, free 8 Cardboard 60 13.8 1.9X1OB 15 mil flat plate, free 3 Styrene 180 2.5 522x10 5 mil flat plate, free- 3 Brass. 500 6. 7 6. 6X107 2mil flat plate, free. 3 SteeL 130 2.5 1.7 10 1 mil flat plate, free 3 do 1. 2 1. 2x10 8 mil flat plate, tight 3 Rubber 120 1. 5 8. 5x10 60 mil flat plate, free 3 Styrene 480 10. 2 9. 3X107 Do 8 do 120 53.8 3.1 10

1 polyethylene.

For each of the above systems, some of which were mounted freely and others of which were mounted rather Another object of the present'invention is to provide a str1ker means for a motor sound device having an impeller on which individual strikers are loosely mounted at random angles.

Other objects and advantages of the present invention will be readily apparent from the following description and drawings, which illustrate a preferred exemplary embodiment of the present invention as well as alternative embodiments of the present invention.

In general, the present invention involves a motor sound device having a vibratile system including a resonator adapted to emit an internal combustion motor sound when struck. Rotatably mounted adjacent said resonator is an impeller having lug means provided on its periphery adapted to strike said resonator during the rotation-of the impeller. Also, the motor sound device has drive means for rotating said impeller.

In one embodiment of the present invention mounted between the impeller and resonator is a bridge which is adapted to move solely substantially perpendicular to the resonator and to translate blows thereon to said resonator. In this embodiment, the impeller includes a plurality of lug-s spaced around its periphery with each of said lugs being retractably mounted on the impeller and adapted to be extended to strike the resonator or bridge by the centrifugal force exerted thereon by the rotation of the impeller and to be retracted by its impact with the bridge or resonator. The lugs may be spaced at random angles of no less than 60 degrees apart and may be made of materials such as wood, plastic and metal having sufiicient mass and velocity to shock-excite the resonator with a lot of resonance.

In anotherv embodiment of the present invention, the

impeller is carried by a shaft adapted to be rotated by the wheel of a vehicle when the shaft is biased into engagement therewith. The shaft is biased against the driving wheel to assure that the impeller will be uniformly driven by the wheel regardless of the amount the wheel wobbles during operation of the vehicle. In this embodiment, the resonator is in the form of a folded cone which is mounted in a thin housing especially adapted for mounting on the inside of a fender adjacent one of the Wheels of the vehicle. Also, in this embodiment the lug means comprises axially-extending irregularities on the periphery and end portions of a cylindrical member having a hemispherical end portion.

The resonator of all embodiments may have a conical shape and may have a stiifness between approximately to 10 dynes per centimeter for a mass of from to 100 grams. The cone is suspended in such a manner as to produce its desired low frequency resonance with the mass of the cone used. The cone has an amplitude capability within the stress limits of the material used, thereby permitting production of a high level of low frequency energy. I

The mass of and the types of material employed in both the lug means and the resonator is such that undamped resonances are minimized, and so that the output from the resonator has a spectrum containing a maximum of energy in frequencies :below approximately 2500 c.p.s.

In order to facilitate understanding of the present invention, reference will now be made to the appended drawings of a preferred specific embodiment of the present invention as well as alternative embodiments of the present invention. Such drawing should not be construed as limiting the invention which is properly set forth in the appended claims.

In the drawings:

FIGURE 1 is a perspective view of a toy auto containing a motor sound device constituting a first embodiment of the present invention;

FIGURE 2 is an enlarged cross-sectional view of a portion of FIGURE 1, taken along the lines 22 of FIGURE 1;

FIGURE 3 is a cross-sectional view of FIGURE 2, taken along the lines 3-3 of FIGURE 2;

FIGURE 4 is a crosssectional view of FIGURE 2, taken along the lines 4-4 of FIGURE 2;

FIGURE 5 is a partially broken-away perspective view of a portion of FIGURE 4;

FIGURE 6 is a plan view corresponding to FIGURE 4 illustrating a second embodiment of the present invention;

FIGURE 7 is an enlarged, partially broken-away perspective view of a portion of FIGURE 6;

FIGURE 8 is a plan view of the impeller portion of FIGURE 4 showing an alternate embodiment of the impeller with a variety of lugs mounted thereon;

FIGURE 9 is a perspective view of an alternate embodiment of the impeller portion of the motor sound device;

FIGURE 10 is a perspective view of still another alternate embodiment of the impeller portion of the present invention;

FIGURE 11 is a cross-sectional view of an alternate embodiment of the resonator of the present invention;

FIGURE 12 is a partial plan view of vehicle in combination with a motor sound device constituting a third embodiment of the present invention;

FIGURE 13 is a perspective view, on an enlarged scale, of the device of FIGURE 12;

FIGURE 14 is an enlarged, partial cross-sectional view of the combination of FIGURE 12;

FIGURE 15 is an enlarged side-elevational view of the motor sound device of FIGURE 12;

FIGURE 16 is an enlarged, partial cross-sectional view of the combination of FIGURE 12; and

FIGURE 17 is an enlarged, partial cross-sectional view taken along lines 17-17 of FIGURE 16.

As illustrated in FIGURES l5, the motor sound device 30 of the present invention may be mounted in a vehicle 20 such as an automobile. The motor sound device includes a resonator 31 adapted to emit an internal combustion motor sound when struck. Mounted adjacent the resonator 31 is a bridge adapted to move solely substantialy perpendicular to the resonator and to translate blows thereon to said resonator. Also, the motor sound device 30 includes a rotatably mounted impeller having at least one lug mounted on its periphery adapted to strike said bridge 40 during the rotation of said impeller 50 and drive means for rotating said impeller.

The vehicle 20 includes a body 21 with the motor sound device mounted therein. The body 21 is carried by the front axle (not shown) having wheels 22 mounted on its ends and a rear axle 23 having wheels 24 mounted on its ends. The body 21 is preferably \made of a synthetic resin or plastic, as indicated by the cross-hatching employed in the drawings. Such materials have a comparatively low resonance frequency so that the body 21 serves as a resonance chamber when employed in conjunction with a motor sound device of the present invention to enhance the sound produced thereby.

Mounted within the body 20 is the motor sound device 30 having a resonator 31 adapted to emit an internal combustion motor sound when struck. The resonator 31 includes a flexible cone 32 mounted on a frame 33 which is attached to the vehicle body 21. The cone 32 has a somewhat thinner cross-section 34 adjacent to the frame 33 to increase its flexibility and has an apex plug 35 adjacent to the remaining portion of the motor sound device 30 Although a number of different types and sizes of cones 32 will manifest themselves, a cone approximately 2% inches in diameter and /2 inch deep, which has a sidewall thickness of approximately 15 millimeters and which is made from a cellulose acetate butyral having a mass of 1.6 grams and a stiffness of 4.0)(10 dynes has been found to be satisfactory. Such a cone has a natural frequency of approximately 250 c.p.s. which is low enough to permit it to respond with a lot of resonance to shock-excitation. The edge support of the cone 32 in frame 33 '2500 c.p.s.

is such that low frequency resonance is obtainable with the mass of the cone used. In addition, the cone 32 has satisfactory amplitude capabilities with material stress limits which permit production of a high level of low frequency energy. When struck with a striker means of the present invention, the output from the cone 32 has an acoustical spectrum containing a maximum of energy in the lower frequencies i.e., below approximately The thinner cross-section 34 of the cone 32 not only serves as a damper for the cone, but also extends the life of the cone by permitting it to roll on the reduced cross-section thereby reducing fatigue.

Mounted adjacent to the resonator 31 and perdendicularly to the apex plug 35 is a bridge 40 which is adapted to move solely substantially perpendicular to the resonator 31 and to translate blows thereon to the resonator 31. The bridge 40 includes a rigid strip 41 of tough material such as plastic which is slidably mounted in grooves 42 in the frame 33 of the resonator 31 with the ends 43 of the strip 21 near the bottoms 44 of the grooves 42. Thus, strip 41 is adapted to slide perpendicular to the resonator 31 and is substantially restrained from sliding parallel to the resonator 31 so that the strip 41 will minimize side loads exerted on the cone 32, by the lugs 60. When the vehicle 20 is pushed along a floor or the like, by a child, the drive means 70 rotates the impeller 50 with sufficient force that the lugs 60 would rapidly errode the plug 35 away if the lugs 60 were to contact it directly.

The impeller 50 is rotatably mounted adjacent to the bridge 40 and has a plurality of lugs 60 spaced around its periphery adapted to strike the bridge 40' during the rotation of the impeller 50. The impeller 50 includes a spindle 51 having an upper reduced end 52 which is rotatably received in a socket 25 of the body 21. Similarly, the spindle 51 has a lower reduced end 53 which is rotatably received in a socket 54 of a case 55 which is mounted on a bridge 26 of the body 21. Mounted around the spindle 51 is a disc 56'.

The lugs 60 are retractably mounted on the impeller 50 and adapted to be extended to strike the 'bridge 40 by the centrifugal force exerted thereon by the rotation of the impeller 50 and to be retracted by their impact with said bridge. The lugs 60 include rings 61 loosely mounted on pivot pins 62 attached to the disc 56 of the impeller The rings 61 have a carefully developed radial compliance designed to excite the cone 32 with a long impulse so that the output from the cone will have a spectrum containing a maximum amount of energy in the lower frequencies. The mass and stiffness of the rings, 61 are such that they will shock-excite the cone 32 with a lot of resonance and with sufiicient higher frequencies to maintain acoustical balance similtaneously with a high acoustical level. It has been found that rings having a W O.D. by V ID. by 4 inch thickness and which are made of an a-cetal resin have a satisfactory mass and stiffness for the velocity imparted to them by the impeller 50.

The impeller 50 is rotated by a driven means 70 which includes a first gear means 71 mounted on the rear axle 23 .of the vehicle 20 and a second gear means 77 mounted on the spindle 51 of the impeller 50. The sec-nd gear means 77 is engaged with the first gear means 71. The first gear means 71 includes a cup gear 72 which is mounted on the rear axle by engaging its central sleeve 73 with a knurled portion 74 of the rear axle 23. The second gear means 77 is produced by forming a gear 78 out of the lower portion of the spindle 51 adjacent its lower end 53. The gear 78 is engaged with the teeth 75 )f the cup gear 72. The drive means 70 also includes 1 flywheel 79 which is coaxial'ly mounted on the disc 56 )f the impeller 50 and forms the connection between the lisc 56 and the spindle 51 of the impeller 50.

The operation of the motor sound device 30 of the toy vehicle 20 of FIGURES 1-5 is very simple but yet achieves sounds closely corresponding to the sounds of an internal combustion motor. When the toy vehicle 20 is moved along a surface with its

wheels

22 and 24 engaged therewith, the wheels 24 rotate the axle 23. The axle 23 in turn rotates the cup gear 72, the gear 78 and thereby rotates thedisc 56 of the impeller -50. The rotation of the impeller 50 extends the rings 61 of the lugs 60 so that they strike the bridge 40. However, when striking the bridge 40, because the rings 61 are loosely mounted on pivot pins 62, they immediately retract after striking the bridge 40 so that the impact of contact therewith is essentially instantaneous. Also, since the bridge is substantially restrained from sliding parallel to the resonator 31 because the ends 43 of a strip 41 are near the bottoms 44 of the grooves 42, the bridge 40 is moved by the impact of the lugs 60 solely substantially perpendicular to the resonator and thereby strikes the apex plug 35 of the cone 32. The cone 32 in turn emits when struck by the bridge 40 a low-pitched sound in a regular cycle depend ing on the placement and configuration of the lugs 60 on the impeller 50 so that the sounds produced closely correspond to the sounds of an internal combustion motor. Alternatively, the strip 41 can be bowed inwardly against plug 35 so that it is in permanent engagement therewith. In either event, the sound produced is substantially the same since the cone 32 is excited with a long pulse by virtue of the radial compliance of the rings 61.

Many other specific embodiments of the present invention will be obvious to one skilled in the art in view of this disclosure. For example, as illustrated in FIGURES 6 and 7 the motor sound device may include simply a resonator 131 adapted to emit an internal combustion motor sound when struck, a rotatably mounted impeller 130 having at least one lug 160 mounted on its periphery adapted to strike the resonator 131 during the rotation of the impeller and drive means, including an electric motor 170, for rotating said impeller. Also, the resonator 131 may include a cone 132 mounted on a frame 133 with the portion 134 of the cone 132 adjacent the frame 133 being corrugated. In addition, the impeller 150 may include lugs wherein rings 161 are loosely mounted on pivot pins 162 attached to the impeller 160. However, the rings 161 may have a U-shaped cross-section 163 with an outwardly extending flange 164 adapted to strike the resonator 131.

The cone 132 may advantageously correspond in size and shape with, and may be made from the same material as, the cone 32 previously described. The bridge 40 described in connection with. the FIGURES 1-4 embodiment may be eliminated from the resonator 131 so that the rings 161 strike the apex plug 135 directly. This is feasible because the motor drives the impeller 150 with less acceleration than is imparted to the impeller 50 of the previous embodiment when the vehicle 20 is pushed along a suitable surface. Thus, the problem of frictional wear on the plug 135 is not as great as it is in connection with the FIGURES 1-4 embodiment. Also, the rings 161 may advantageously have a different radial compliance than the rings 61 and are preferably made of a softer material than the rings 60. For example, the rings 161 may be advantageously made of polyethylene having a modulous of elasticity of approximately 100,000 p.s.i. in lieu of the acetal resin rings used in the previous embodiment. The FIGURE 7 configuration of the rings 161 is an important feature of the device 130. It 'has been tound in actual practice that such a configuration in combination with an electrically driven rotor or impeller 150 and the particular cone 132 disclosed herein produces a sound corresponding more nearly to the sound produced by a typical automobile engine than is produced when other shaped rings are employed in the same system.

The motor 170 for the sound device 130 is preferably a DC. motor so that its operating rate is proportional to the input voltage to the motor 170. Consequently, the

' intensity and rapidity of repetition of the sounds produced by the motor sound device 130 is proportional to the input voltage to the electric motor 170'.

Still other specific embodiments of the present invention are illustrated in FIGURES 8-11. In FIGURE 8, the impeller 250 includes a plurality of lugs 260 spaced around its periphery. Each lug includes a ring 261 having a variety of shapes such as substantially ellipsoidal 261a circular 261b, triangular 261a, and irregular 261d. Similarly, the pivot pins 262 on which the rings 261 are mounted may be spaced varying distances from the center of the impeller 250.

The impeller 250 may be use-d in place of the impeller 50 in the sound device 30 or alternatively, it may be used in place of the impeller 150 in the motor sound device 130. When used in the sound device 30 the

rings

261a, and 26111, 2610 and 261d are preferably made from a material such as an acetal resin having a modulous of elasticity of approximately 400,000 p.s.i. On the other hand, when employed in conjunction with the sound device 130, these rings are preferably made from a polyethylene material having a modulous of elasticity of approximately 100,000 p.s.i. Also, when used in the motor sound device 30, the rings 261a-261d preferably have a mass equivalent to the mass of the rings 61 and when used in the motor sound device 130, the rings preferably have a mass comparable to that of the rings 161. The random shape of the rings 261a-261d enhances the motor sound produced by the device in which the rings are employed by imparting a rumble to the sound produced by the motor sound device.

In FIGURE 9, the impeller 350 includes a spindle 351 having a bracket 352 mounted thereon with arms 353 extending outwardly. Dependent from the arms 353 are flexible struts 354 supported at the bottom by a flexible brace ring 355. Mounted on the struts 354 are knobs 356 which are adapted to strike the bridge or resonator.

The impeller 350 may be mounted in the body 21 of the vehicle 20 by

pivot pins

252 and 253 provided on the upper and lower ends thereof, respectively. A gear 278 may be provided on the lower end of the impeller 350 for actuation by the gear 72 in vehicle 20 so that the impeller 350 will be driven thereby.

The knobs 356 preferably have a modulous of elasticity within the range of about 100,000-400,000 p.s.i.

In FIGURE 10, the impeller 450 has a spindle 451 on which are mounted a plurality of outwardly extending arms 452 with each of said arms having a knob 453 mounted on the end'thereof.

The impeller 450 may be mounted in the vehicle 20 in such a manner that a gear 478 provided on the impeller 450 engages the driving gear 72 provided in the vehicle 20. The arms 452 and their associated knobs 453 are preferably made from a non-metallic material having a modulous of elasticity within the range of about 100,000 p.s.i.-400,000 p.s.i.

In FIGURE 11, the resonator 531 includes a cone 532 with an apex plub 533 having a chamber 534 therein. Contained within the chamber 534 are a plurality of freely movable weights 535. The chamber 534 of the plug 533 may be simply formed by capping the chamber 534 in the cone 532 with a cover 536 mounted on the interior surface of the cone 532.

The cone 532 is preferably made from the same material as the

cones

32 and 132 and the weights 535 preferably comp-rise spherical balls made of a suitable plastic, such as an acetal resin or the like. The weights 535 not only enhances the random nature of the sound produced by the cone 532 when it is struck by any of the impellers previously shown and described herein, but also serves as a damper for the cone 532.

Referring now to FIGURES 12-17, a device for simulating motor sounds constituting a third embodiment of the present invention, generally designated 610, is shown for purposes of illustration but not of limitation as being affixed to a vehicle 620 for operation thereby.

The vehicle 620, which may comprise a velocipede, such as a bicycle or a tricycle, or any other wheeled vehicle used by children is shown herein for purposes of illustration, but not of limitation, as being of the type having a pair of steerable rear wheels, one of which is shown at 624 in FIGURE 12. The vehicle 620 may be steered by a control lever 624a and includes a body portion 621 upon which a seat 62% is mounted. A front wheel 622 is also mounted on the body portion 621 and may be rotated by suitable pedal-driven cranks, as the one shown at 626. The vehicle 620 also includes a front fender assembly 627 having a rear wall 627a and a sidewall 627b which cover the wheel 622. The sidewall 627b is provided with an apertured, recessed portion 627c in which a motor sound device 630 may be mounted in such a manner that sounds emanating therefrom will readily pass through the apertures provided therein.

The motor sound device 630 includes a resonator means 631 adapted to emit an internal combustion motor sound when struck or shock-excited with a lot of resonance. The resonator means 631 includes a folded cone 632 mounted in a frame 633 which is attached to the sidewall 627b by suitable bolts 628 (FIGURE 15) which pass through hollow, cylindrical bosses 633a provided on the frame 633. The cone 632 has a corrugated portion 634 adjacent the frame 633 and a dished portion 632a to which a spherical member 635 is attached. As clearly shown in FIGS. 14 and 16, cone 632 also has an encompassing sidewall portion 632b connecting the corrugated portion 634 to the dished portion 632a.

Although a number of different types and sizes of cones 632 will manifest themselves, a cone approximately 3% inches in diameter and inch deep, which is made from a cellulose acetate butyral having a mass of from 1 to 2 grams and a stiffness of from 10 to 10 dynes per centimeter has been found to be satisfactory. Such a cone has a natural frequency of approximately 250 c.p.s. which is low enough to permit it to respond with a lot of resonance to shock-excitation. The edge support of the cone 632 in frame 633 is such that low frequency resonance is obtainable with the mass of the cone used. In addition, the cone 632 has satisfactory amplitude capabilities with material stress limits which permit production of a high level of low frequency energy. When struck with a striker means to be hereinafter described, the output from the cone 632 has an acoustical spectrum containing a maximum of energy in the lower frequencies i.e., below approximately 2500 c.p.s. The corrugated portion 634 of the cone 632 not only serves as a damper for the cone, but also extends the life of the cone by permitting it to roll on the corrugated portion thereby reducing fatigue. The folded nature of the cone 632 is an important feature of the third embodiment of the present invention because it permits making a relatively thin motor sound device 630 which may be conveniently mounted between the fender 627 and wheel 622.

The frame 633 may be conveniently injection molded from a high-impact polystyrene plastic material and includes a flat, closed bottom wall 633b, an encompassing sidewall 6330 and an open top 633d. The open top 633d is surrounded by an annular flange 633e which is provided with an annular groove 633 forming an edge support for the cone 632. The bottom wall 633b and the sidewall 6330 are provided with a common rectangular slot 633g in which a striker means 650 is swingably mounted by pins 651. The striker means 650 includes a frame 652 having a first end 652a to which the pins 651 are afiixed in such a manner that each pin may be engaged in an aperture 63311 provided in a bracket 633i formed integrally with the bottom wall 633b.

The striker means 650 also includes an impeller means 653 which is aflixed to one end 654:: of a shaft 654 which is journaled in a pair of brackets 655 in the frame 652.

A friction wheel 656 is non-rotatably mounted on the other end 654b of the shaft 654 for imparting rotation thereto when the wheel 656 is swung into engagement with the vehicle wheel 622. The friction wheel 656 may be swung into engagement with the wheel 622 and biased into engagement therewith by swinging the frame 652 on its pins 651 by manipulating a control member 657. The member 657 includes an actuating handle 657a which is mounted in a slot 627d provided in the rear wall 627a of fender 627 for actuation by a user of the vehicle 620 to simulate the operation of the controls of a powered vehicle. The control member 627 also includes a control wire 65712 having a U-shaped end 6570 engaging the handle 657a and an end 657d passing through a slot 633 provided in a fulcrum 633k on frame 633. The end 657d also passes through a slot 65% provided in a bracket 6520 on the end 652a of frame 652. Actuation of the handle 657a upwardly in the direction of arrow A (FIG- URE 13) moves the control wire 65711 to its broken line position whereupon the end 657d swings downwardly, as indicated by arrow B. This causes friction wheel 656 to swing in the direction of arrow C into engagement with vehicle wheel 622. The wire 657b will then exert a constant force on frame 652 biasing the friction wheel 656 against the vehicle wheel 622. This is an important feature of the third embodiment of the present invention because it assures that the friction wheel 656 will be maintained in proper driving engagement with the vehicle wheel 622 regardless of the amount the wheel 622 wobbles as it rotates.

The swinging of frame 652 in the direction of arrow C causes the impeller means 653 to be swung into engagement with the spherical member 635, as shown in FIG- URE 16, for imparting repetitive shocks thereto during rotation of impeller means 653 by wheel 656 and shaft 654. These repetitive shocks excite the cone 632 with a lot of low frequency resonance causing it to emit a sound simulating the sound of an internal combustion engine. The spherical member 635 is biased into engagement with the impeller means 653 by a compression spring 635a having one end 6351) seated on member 635 and another end 536c bearing against fender 627 in recess 6270.

The impeller means 653 includes an integral upper cylindrical portion 653a and a hemispherical lower portion 653b which assure operative engagement of the impeller means 653 with the member 635 regardless of the changing position of friction wheel 656 by virtue of the wobble in wheel 622. The impeller means 653 is provided with lug means 660 in the form of a series of axially-extending irregularly spaced obstructions or striker elements 661 which are adapted to subject the cone 632 to repetitive shock-excitation when the impeller means 653 is rotated while engaging the spherical member 635. The member 635 serves to prevent the obstructions 661 from eroding the cone 632 and may be manufactured from relatively tough, abrasion-resistant materials such as steel, synthetic resin polystyrene and the like. The impeller means 653 may be conveniently manufactured from relatively tough, somewhat resilient materials such as brass, synthetic resin, polystyrene and the like. A spherical member 635 having a inch diameter and an impeller means 653 having a inch diameter have been found to be satisfactory.

While the particular devices for simulating motor sounds herein shown and described in detail are fully capable of attaining the objects and providing the advantages hereinbefore stated, it is to be understood that they are merely illustrative of the presently preferred embodiments of the invention and that no limitations are intended to the details of construction or design herein shown other than as defined in the appended claims.

What is claimed is: 1. A device for producing sounds simulating the sounds produced by an internal combustion engine, comprismg:

frame means including a closed bottom wall, an encompassing side wall and an open top, said side wall and said bottom wall having aligned slots provided therein;

resonator means mounted in said open top, said resonator means being of the folded-cone type and having a low-pitched natural frequency and being adapted to produce a noise simulating the noise produced by an internal combustion engine when subjected to repetitive shock-excitation, said resonator means having a dished portion extending toward said open p;

impeller means for subjecting said resonator means to said shock-excitation; impeller frame means swingably mounted in said aligned slots by means of a pivotal connection to said bottom wall, said impeller means being journaled in said impeller frame means, said impeller means having a first end positioned in said slot in said bottom wall in alignment with said dished portion and a second end extending through said slot in said side wall to a position externally of said frame means, said pivotal connection means of said impeller frame means being arranged in such a manner that pivoting of said impeller frame means causes said first end to swing on an arc toward said dished portion while said second end is swinging on an are away from said open top, said first end being provided with a cylindrical member having obstructions provided thereon for subjecting said resonator means to said shock-excitation when said first end is swung into engagement therewith during rotation of said impeller means, said second end being provided with a friction wheel engageable with a rotating surface to impart rotation to said impeller means when said second end is swung away from said open top; and

control means connected to said impeller frame for swinging said friction wheel into engagement with said rotating surface and simultaneously swinging said cylindrical member into engagement with said dished portion.

2. A device for producing sounds simulating the sounds produced by an internal combustion engine including resonator means having a low-pitched natural frequency and being adapted to produce a noise simulating the noise produced by an internal combustion engine when subjected to repetitive shock-excitation and means for subjecting said resonator means to repetitive shock-excitation, characterized in that said resonator means comprises a non-metallic, vibratile, generally circular diaphragm comprising reversely tapering conical portions arranged in radial alignment for minimizing the axial space occupied thereby, said diaphragm including an annular corrugated portion radially outwardly of said conical portions, said diaphragm having a low-pitched natural frequency substantially less than 2500 c.p.s., said diaphragm being adapted to produce indiscriminate noise simulating the noise produced by an internal combustion engine when subjected to repetitive shock-excitation wherein the bulk of the noise has a frequency below approximately 2500 c.p.s.

3. In combination with a vehicle having a rotatable vehicle wheel and a fender covering said rotatable wheel, a device for producing sounds simulating the sounds produced by an internal combustion engine, comprising:

an apertured recess provided in said fender adjacent said rotatable wheel and defining a speaker grill for said device;

non-metallic vibratile resonator means mounted in said recess between said grill and said wheel, said resonator means having a low-pitched natural frequency substantially less than 7500 c.p.s., said resonator means being adapted to produce indiscriminate noise simulating the noise produced by an internal combustion engine when subjected to repetitive shockexcitation wherein the bulk of the noise has a fre quency below approximately 2500 c.p.s., said resonator means comprising a generally circular diaphragm comprising reversely tapered conical portions arranged in radial alignment whereby to minimize the depth of said recess; and

actuating means operatively associated with said resonator means and said vehicle wheel for subjecting said resonator means to said repetitive shock-excitation.

4. A device as defined in claim 3 wherein said actuating means includes a friction wheel selectively movable into rolling engagement with a side of said vehicle wheel, and resilient means for biasing said friction wheel into engagement with said vehicle wheel regardless of wobble 'of the latter during rotation thereof.

5. A device as defined in claim 4 wherein said fender is provided with a slot therein, control means slidable in said slot and connected to said friction wheel for selectively moving the same into engagement with said vehicle wheel.

References Cited by the Examiner UNITED STATES PATENTS Codd 116-143 Overholt 116-143 Cowey 116143 Bujger 46--112 M-uller 46-111 Countryman et al. 46175 Gordon 46175 Clemens 46175 Sperry et al. 46175 RICHARD C. PINKHAM, Primary Examiner.

20 L. J. BOVASSO, Assistant Examiner.

Claims

3. IN COMBINATION WITH A VEHICLE HAVING A ROTATABLE VEHICLE WHEEL AND A FENDER COVERING SAID ROTATABLE WHEEL, A DEVICE FOR PRODUCING SOUNDS SIMULATING THE SOUNDS PRODUCED BY AN INTERNAL COMBUSTION ENGINE, COMPRISING: AN APERTURED RECESS PROVIDED IN SAID FENDER ADJACENT SAID ROTATABLE WHEEL AND DEFINING A SPEAKER GRILL FOR SAID DEVICE; NON-METALLIC VIBRATILE RESONATOR MEANS MOUNTED IN SAID RECESS BETWEEN SAID GRILL AND SAID WHEEL, SAID RESONATOR MEANS HAVING A LOW-PITCHED NATURAL FREQUENCY SUBSTANTIALLY LESS THAN 7500 C.P.S., SAID RESONATOR MEANS BEING ADAPTED TO PRODUCE INDISCRIMINATE NOISE SIMULATING THE NOISE PRODUCED BY AN INTERNAL COMBUSTION ENGINE WHEN SUBJECTED TO REPETITIVE SHOCKEXCITATION WHEREIN THE BULK OF THE NOISE HAS A FREQUENCY BELOW APPROXIMATELY 2500 C.P.S., SAID RESONATOR MEANS COMPRISING A GENERALLY CIRCULAR DIAPHRAGM COMPRISING REVERSELY TAPERED CONICAL PORTIONS ARRANGED IN RADIAL ALIGNMENT WHEREBY TO MINIMIZE THE DEPTH OF SAID RECESS; AND ACTUATING MEANS OPERATIVELY ASSOCIATED WITH SAID RESONATOR MEANS AND SAID VEHICLE WHEEL FOR SUBJECTING SAID RESONATOR MEANS TO SAID REPETITIVE SHOCK-EXCITATION.