AU2006294422B2 - Spray caps for generating spraying sounds having enhanced perceived loudness - Google Patents

Abstract

A spray cap for generating a spraying sound having enhanced perceived loudness, the spray cap having an acoustic structure provided around a nozzle to modify a spraying sound produced by spraying through the nozzle as a function of sound pressure level and frequency into a modified spraying sound having a sound spectrum in a sensitive part of the spectrum of human hearing.

Description

1 SPRAY CAPS FOR GENERATING SPRAYING SOUNDS HAVING ENHANCED PERCEIVED LOUDNESS FIELD OF THE INVENTION The present invention relates to spray caps for consumer spray products, for example, consumer aerosol or pump spray products. BACKGROUND OF THE INVENTION Loudness is the most basic information contained in a sound signal. In consumer aerosol or pump spray products, the loudness of the spraying sound can audibly convey useful information to consumers. For example, loudness can audibly warn when spraying is activated. Loudness can also audibly indicate characteristics of spraying, for example, spray rate, spray quantity, spray quantity, spray range, etc. The safety and efficacy of consumer spray products can therefore be improved by enhancing (or increasing) the perceived (or perceptual) loudness of their spraying sound. SUMMARY OF THE INVENTION According to the present invention, there is provided a spray cap for generating a spraying sound having enhanced perceived loudness, the spray cap having an acoustic structure provided around a nozzle to modify a spraying sound produced by spraying through the nozzle as a function of sound pressure level and frequency into a modified spraying sound having a sound spectrum in a sensitive part of the spectrum of human hearing, characterised in that the acoustic structure is a hollow, generally rectangular parallelepiped. The sound pressure levels of the modified spraying sound can range from around 65 dB to around 100 dB at frequencies in a range of around 2 kHz to around 6 kHz. Preferably, the sound pressure levels of the modified spraying sound range from around 80 dB to around 90 dB at frequencies in a range of around 3 kHz to around 5 kHz. More preferably, the sound pressure levels of the modified spraying sound peak in a range from around 85 dB to around 90 dB at a peak frequency of around 4 kI-Iz. Further preferably, the sound spectrum of the 2 modified spraying sound has.a generally inverted cup or inverted "U" shape when viewed as a function of sound pressure level and frequency between around 2 kHz and around 6 kHz. The modified spraying sound can audibly wam when spraying through the nozzle is activated. The modified spraying sound can audibly indicate information about spraying through the nozzle selected from spray rate, spray quantity, spray quality, spray range, spray efficacy, and combinations thereof. The hollow, generally rectangular parallelepiped can have a curved upper rear internal surface. The internal surface area of the hollow, generally rectangular parallelepiped can be substantially smooth. The spray cap can further include a skirt having a peripheral lip adapted to snap-fit on top of. a spray container. The peripheral lip can have an offset hanger portion adapted to removably hang a spray container in a vertical direction longitudinal to and substantially parallel to a wall when the spray cap is snap-fitted on top of a spray container. The offset hanger portion can be adapted to removably engage a complementary upstanding hook provided on a wall storage bracket. The offset hanger portion and the complementary upstanding hook can be arcuate in horizontal section. The nozzle, acoustic structure and skirt can be integrally formed with an actuator. The nozzle, acoustic structure, skirt and actuator can be formed as an integral moulding in plastics. Embodiments of the present invention also provide a spray product for generating a spraying sound having enhanced perceived loudness, the spray product having the above spray cap mounted on a spray container containing spray liquid and/or propellant. The spray product can be an aerosol spray product or a pump spray product. Embodiments of the present invention further provide a method for enhancing a perceived loudness of a spraying sound generated by a spray cap, the method including the steps of; providing an acoustic structure around a nozzle of a spray cap; configuring the acoustic structure to modify a spraying sound produced by spraying through the nozzle as a function of sound pressure level and frequency into a modified spraying sound having a sound spectrum in a sensitive part of the spectrum of human hearing. 18486446v1 MHIL 3 Embodiments of the present invention also provide a method for enhancing a perceived loudness of a spraying sound generated by a spray cap having an acoustic structure provided around a nozzle, the method including selectively and individually configuring the nozzle and the acoustic structure to modify a spraying sound produced by spraying through the nozzle as a function of sound pressure level and frequency into a modified spraying sound having a sound spectrum in a sensitive part of the spectrum of human hearing. The step of selectively and individually configuring the nozzle and the acoustic structure can be based at least in part on sound characteristics of spray liquid and/or propellant to be sprayed through the nozzle. Embodiments of the present invention also provide a kit of parts including a spray cap, a spray container and a wall storage bracket, the spray cap including an acoustic structure provided around a nozzle to modify a spraying sound produced by spraying through the nozzle as a function of sound pressure level and frequency into a modified spraying sound having a sound spectrum in a sensitive part of the spectrum of human hearing, the spray cap further including a skirt having a peripheral lip adapted to mount the spray cap on top of the spray container, and the peripheral lip having an offset hanger portion adapted to removably engage a complementary upstanding hook provided on the wall storage bracket, wherein the spray cap and the wall storage bracket cooperate to removably store the spray container [INTENTIONALLY LEFT BLANK] 18486446v1 MHIL WO 2007/033426 PCT/AU2006/001390 -4 in a vertical direction longitudinal to and substantially parallel to a wall when the spray cap is mounted on top of the spray container. BRIEF DESCRIPTION OF THE DRAWINGS 5 The present invention will now be described by way of example only with reference to the accompanying drawings, in which: Figure 1 is an exploded perspective view of a consumer spray product including a spray cap of an embodiment of the invention, a spray container and a wall storage bracket; 10 Figure 2 is a section through the spray product of Figure 1; and Figure 3 are sound spectra of spraying sounds generated by the spray cap of Figure 1 and a conventional spray nozzle. DETAILED DESCRIPTION 15 Figures 1 and 2 illustrate a consumer spray product 2 that generally includes a spray cap 4 of an embodiment of the invention, a spray container 6 and a wall storage bracket 8. The spray container 6 is, for example, an aluminium (or tinplate) cylindrical (or ovoid) aerosol can containing liquid and propellant. The spray cap 4 is, for example, a spray-through cap 20 formed with a nozzle 10, an actuator 12 and a skirt 14 as an integral moulding in plastics, such as polypropylene. When the spray cap 4 is placed on top of the spray container 6, the nozzle 10 is fluidly connected to a valve 16 of the spray container 6. The valve 16 is selectively activated by 25 downwards finger pressure on the actuator 12. The skirt 14 has a peripheral lip 18 that snap-fits on top of the spray container 6. The peripheral lip 18 has an offset hanger portion 20 to removably engage a complementary upstanding hook 22 on the wall storage bracket 8. The wall storage bracket 8 can be fixed to a wall (not shown) by an adhesive strip 24. The complementary parts of the spray cap 4 and the wall storage bracket 8 have a 30 curvature in horizontal section that generally corresponds to the external curvature of the spray container 6. The spray cap 4 and the wall storage bracket 8 cooperate to allow the WO 2007/033426 PCT/AU2006/001390 -5 consumer spray product 2 to be stored in a vertical direction longitudinal to and substantially parallel to a wall when not in use. An acoustic structure 26 is provided around the opening of the nozzle 10. The acoustic 5 structure 26 is provided between two spaced internal transverse walls lying in a vertical plane and extending downwards from the top of the spray cap 4. The acoustic structure 26 is, for example, a hollow, generally rectangular parallelepiped with a curved upper rear internal surface 28. The internal surface area of the acoustic structure 26 is substantially smooth and free of surface features such as ribs, grooves, roughening, etc. The acoustic 10 structure 26 has, for example, an internal height of 28 mm, an internal width of 12.5 mm, and an internal depth of 14 mm. The opening of the nozzle 10 projects into the acoustic structure 26 by 7.5 mm, so that the internal distance between the opening of the nozzle 10 and the front opening of the acoustic structure 26 is 5 mm. The opening of the nozzle 10 is, for example, a vertical slot that produces a fan-like vertical spray pattern. Other shapes, 15 configurations and dimensions are possible for the acoustic structure, nozzle and spray pattern, for example, hollow, continuous frustoconical or frustopyramidal structures, circular nozzle openings, cone-like spray patterns, etc. When the consumer spray product 2 is activated, the spray cap 4 generates a spraying 20 sound having enhanced (or increased) perceived (or perceptual) loudness. The acoustic structure 26 of the spray cap 4 passively modifies sound produced by spraying through the nozzle 10 by translating, transducing, amplifying, and/or converting its tones, sub-tones and component frequencies and levels into those in a sensitive part of the spectrum of human hearing. The acoustic structure 26 therefore modifies the spraying sound as a 25 function of frequency and level (or amplitude) to thereby increase its perceived loudness. The human ear subjectively perceives loudness in a complex way that depends on frequency and level. The human ear preferentially perceives particular frequencies, or bands of frequencies, over others. Fletcher and Munson determined that human hearing is 30 less sensitive at low and high frequencies than at middle (or voice) frequencies. They also found that the relative change in sensitivity decreased as the level of sound increased.

WO 2007/033426 PCT/AU2006/001390 -6 The acoustic structure 26 is tuned to modify a spraying sound produced by aerosol spraying through the nozzle 10 as a function of sound pressure level and frequency into a modified spraying sound having a sound spectrum in a sensitive part of the spectrum of 5 human hearing. The sound pressure levels of the modified spraying sound generated by the spray cap 4 with the acoustic structure 26 can range from around 65 dB to around 100 dB at frequencies in a range of around 2 kHz to around 6 kHz. Sound pressure levels below around 65 dB are considered insufficient to audibly convey useful information about consumer spray products, while levels above around 100 dB are considered undesirable 10 and unpleasant in consumer spray products. Preferably, the sound pressure levels of the modified spraying sound range from around 80 dB to around 90 dB at frequencies in a range of around 3 kHz to around 5 kHz. More preferably, the sound pressure levels of the modified spraying sound peak in a range from around 85 dB to around 90 dB at a peak frequency of around 4 kHz. The amplitude ceiling (highest amplitude sound pressure level 15 in the sound) of around 85 dB and peak frequency of around 4 kHz (frequency at which the highest amplitude sound pressure level occurs) of the modified spray sound positively correlate with increased perceived loudness. Further preferably, the sound spectrum of the modified spraying sound has a generally inverted cup or inverted "U" shape when viewed as a function of sound pressure level and frequency between around 2 kHz and around 6 20 kHz. Figure 3 illustrates comparative sound spectra of spraying sounds generated by the spray cap 4 and a conventional aerosol spray cap having a nozzle without an acoustic structure. Compared to the conventional spray cap, the frequency/sound pressure level profile of the 25 modified spraying sound generated by the spray cap 4 correlates with increased perceived loudness. In other words, the modified spraying sound generated by the spray cap 4 has enhanced perceptual loudness and greater auditory selectivity as a function of frequency and sound level. The sound pressure level of the spray cap 4 in the frequency range of around 3 kHz to around 5 kHz, and at the peak frequency of around 4kHz, is around 20 dB 30 greater than that of the conventional spray nozzle. This significant increase occurs at the point in the acoustic spectrum where the human ear is most sensitive. A 20 dB increase in WO 2007/033426 PCT/AU2006/001390 -7 level in this frequency sub-range is accepted as a factor of four change in loudness. In addition, the overall (A) weighted sound pressure level in dB(A) of the spray cap 4 is almost 10 dB greater than the conventional spray nozzle. The (A) weighted level is an accepted single number descriptor of sound level corresponding to human hearing. A 5 change of 10 decibels in (A) weighted sound pressure level is accepted as an approximate factor of two change in loudness, that is a doubling of loudness. The sound spectra in Figure 3 therefore indicate that the perceived change in loudness between the two spray caps falls between that indicated by the change in overall (A) weighted levels and the change in levels at 4kHz. In other words, the perceived change in loudness is greater than 10 a factor of two and less than a factor of four. The increased perceived loudness of the spraying sound of the consumer spray product 2 generated by the spray cap 4 audibly conveys useful information to consumers. The increased perceived loudness audibly warns consumers when spraying through the nozzle 15 is activated. In addition, the increased perceived loudness audibly indicates information about spraying through the nozzle selected from spray rate, spray quantity, spray quality, spray range, spray efficacy, etc. Embodiments of the invention therefore provide spray caps and consumer spray products 20 having improved safety and efficacy due to the enhanced perceived loudness of their spraying sound. The invention can be implemented with any and all conventional consumer aerosol or pump spray products, for example, cosmetic spray products, personal care spray products, paint spray products, automotive spray products, household/maintenance spray products, insecticidal spray products, industrial spray 25 products, pharmaceutical spray products, food spray products, arts and craft spray products, shoe and leather care spray products, gardening spray products, etc. The shape, dimensions and arrangement of the acoustic structure, nozzle, spraying liquid and/or propellant can be selectively and individually varied to generate spraying sounds having sound pressure levels and frequencies that correlate with enhanced or increased perceived 30 loudness which is subjectively considered to be desirable in consumer spray products.

WO 2007/033426 PCT/AU2006/001390 The above embodiment has been described by way of example only and modifications are possible within the scope of the invention disclosed.

Claims (16)

1. A spray cap for generating a spraying sound having enhanced perceived loudness, the spray cap having an acoustic structure provided around a nozzle to modify a spraying sound produced by spraying through the nozzle as a function of sound pressure level and frequency into a modified spraying sound having a sound spectrum in a sensitive part of the spectrum of human hearing, characterised in that the acoustic structure is a hollow, generally rectangular parallelepiped.

2. A spray cap according to claim 1, wherein the sound pressure levels of the modified spraying sound range from around 65 dB to around 100 dB at frequencies in a range of around 2 kJIz to around 6 kHz.

3. A spray cap according to claim 2, wherein the sound pressure levels of the modified spraying sound range from around 80 dB to around 90 dB at frequencies in a range of around 3 kHz to around 5 kHz.

4. A spray cap according to claim 3, wherein the sound pressure levels of the modified spraying sound peak in a range from around 85 dB to around 90 dB at a peak frequency of around 4 kHz.

5. A spray cap according to claim 4, wherein the sound spectrum of the modified spraying sound has a generally inverted cup or inverted "U" shape when viewed as a function of sound pressure level and frequency between around 2 kHz and around 6 kHz.

6. A spray cap according to any preceding claim, wherein the modified spraying sound audibly warns when spraying through the nozzle is activated.

7. A spray cap according to any preceding claim, wherein the modified spraying sound audibly indicates information about spraying through the nozzle selected from spray rate, spray quantity, spray quality, spray range, spray efficacy, and combinations thereof.

8. A spray cap according to claim 1, wherein the hollow, generally rectangular parallelepiped has a curved upper rear internal surface.

9. A spray cap according to claim 1 or 8, wherein the internal surface area of the hollow, generally rectangular parallelepiped is substantially smooth. 10

10. A spray cap according to any preceding claim, further including a skirt having a peripheral lip adapted to snap-fit on top of a spray container.

11. A spray cap according to claim 10, wherein the peripheral lip has an offset hanger portion adapted to removably hang a spray container in a vertical direction longitudinal to and substantially parallel to a wall when the spray cap is snap-fitted on top of a spray container.

12. A spray cap according to claim 11, wherein the offset hanger portion is adapted to removably engage a complementary upstanding hook provided on a wall storage bracket.

13. A spray cap according to claim 12, wherein the offset hanger portion and the complementary upstanding book are arcuate in horizontal section.

14. A spray cap according to any one of claims 10 to 13, wherein the nozzle, acoustic structure and skirt are integrally formed with an actuator.

15. A spray cap according to claim 14, wherein the nozzle, acoustic structure, skirt and actuator are formed as an integral moulding in plastics.

16. A spray cap substantially as hereinbefore described with reference to the accompanying drawings.