BRIEF DESCRIPTION OF THE DRAWINGS
- DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
- Figure 1 is a view of an exemplary embodiment of the present invention.
- Figures 2a through 2g are views of one embodiment of a sound effects module
in accordance with the present invention.
- Figures 3a through 3g are views of another embodiment of a sound effects
module in accordance with the present invention.
- Figures 4a through 4g are views of still another embodiment of a sound effects
module in accordance with the present invention.
- Figures 5a through 5g are views of still another embodiment of a sound effects
module in accordance with the present invention.
Referring to Figure 1, a water gun generally indicated by the numeral 20 is
provided with a sound effects module, generally indicated by the numeral 22, to
provide sound effects in conjunction with the operation of the water gun. In a typical
application, the water gun will be of the elastic bladder type, wherein water is forced
into the bladder to expand the bladder, with water being expelled from the gun on
pulling the trigger of the water gun as a result of the elasticity of the bladder. Water
guns of this general type are well known in the art, with merely a sample of such
devices being disclosed in U.S. Patent Nos. 4,591,071, 4,854,480, 5,219,096, 5,735,440
The sound effects module 22 in a typical application will be connected to a
switch actuated by the trigger 21 of the water gun 20, so that the sound effects will be
coincidental with the discharge of water from the water gun 20. Such sound effects
may be fixed, such as simulating a machine gun or the like, or may be user selectable to
simulate various real and/or imaginary weapons, such as machine guns, laser or other
beam type weapons, other weapons of science fiction, etc. In that regard, any of
various sound signal generating devices may be used, such as by way of example,
single chip analog or digital storage and playback devices, such as, by way of example,
the analog storage and playback devices manufactured by Information Storage Devices,
Inc. of San Jose, California.
It is important to note that implementing an air-tight compression chamber to
achieve a waterproof environment is not advisable as pressure differentials between the
front and rear of the speaker caused from air freight or heat variations would cause the
speaker to deform or potentially become damaged. Pressure differentials across the
speaker will cause the speaker to have significant distortion during operation.
In the water gun environment, it is important that the sound effects module is
capable of operation in a wet and humid environment and over some significant
temperature range, as the water gun 20 may be exposed to relatively cool tap water or
left in the sun on a summer day to warm up to 50-75° Fahrenheit above cool tap water
temperatures. Accordingly, it is desired to have the sound effects module be water
resistant. While absolute water resistance, which might be referred to as "waterproof,''
would be ideal, the cost of achieving absolute water resistance may not be justified
from an economic standpoint nor required from a functional standpoint.
Figures 2a-2g, 3a-3g, 4a-4g, and 5a-5g, disclose four exemplary alternate
approaches for achieving the desired water resistance of the sound effects module 22.
As is representative of the embodiments of Figures 2a-2g, 3a-3g, 4a-4g, and 5a-5g,
Figures 2a-2g illustrate the general construction of the sound effects module. In
particular, adjacent one end of the sound effects module housing 24 is a mylar speaker
26, sealed around a periphery to the module housing 24 by the configuration of the
speaker cover 28. The mylar speaker 26 has an electromechanical actuator 50 and a
speaker cone 52 made of mylar or other water impermeable material. The actuator 50
converts electrical signals to mechanical vibrations. The speaker cone 52 is glued to
the actuator 50 so that vibrations of the actuator 50 propagate into the speaker cone 52.
The speaker cover 28 provides protection from mechanical damage for the mylar
speaker 26 while also having openings to allow sound created by the mylar speaker 26
to propagate from the speaker-cone 52.
Figure 2d illustrates an exemplary configuration of the speaker cover 28.
Figures 2a-2f illustrate the mylar speaker 26, the speaker cover 28, the module housing
24, a speaker seal 202, a speaker cover seal 204, a ring 206 of the speaker cover 28 and
a land 208 of the module housing 24. The mylar speaker 26 closes the end of the
module housing 24 so that speaker cone 52 prevents water from entering the module
housing. Figures 2a, 3a, 4a, and 5a are magnified views of the seals that may be
provided around the speaker cover 28, the mylar speaker 26 and the module housing 24
in each embodiment. The seal between the end cover 29 and the module housing 24
may be similar to that of the seal provided between the speaker cover 28 and the
module housing 24. The seal between the removable battery door 32 and the end cover
29 may be similar to that of the seal provided between the speaker cover 28 and the
module housing 24. Figures 2g, 3g, 4g, and 5g are magnified views of the seals that
may be provided between the cover 36 and the module housing 24 in each embodiment.
The seal between the cover 36 and the module housing 24 may be similar to that of the
seal provided between the speaker cover 28 and the module housing 24.
The speaker cover 28 is fastened to the module housing 24 by fasteners, threads
formed on the speaker cover 28 and the module housing 24 or other attachment devices
well known in the art. The speaker cover 28 captures the mylar speaker 26 and presses
the mylar speaker 26 against the speaker seal 202. The speaker seal 202 in one
embodiment is an "O" ring type of seal. Thus, the mylar speaker 26 and the module
housing 24 compress the speaker seal 202 to seal the module housing 24 and mylar
speaker 26. The sound effects module 22 may also include a speaker cover seal 204.
Speaker cover 28 may have a tongue, projection or ring 206 which presses the speaker
cover seal 204 against the groove, race or land 208 thereby sealing the ring 206 and
land 208. While both speaker seal 202 and speaker cover seal 204 have been shown, it
is understood that only the speaker seal 202 is required to seal the mylar speaker 26 and
module housing 24.
At the other end of the sound effects module 22 is an end cover 29 with a
battery case 30. A removable battery door 32 couples to the end cover 29 sealing the
periphery of the battery case 30. Batteries 31 may be installed in the battery case. The
batteries 31 are electrically connected to circuitry such as a printed circuit board in a
compartment 33. The compartment 33 is sealed at the bottom with a cover 34 and
sealed at the top with a second cover 36, having a silicon rubber keypad 48 thereon for,
sound effects selection, etc., the exact configuration of which will depend upon the
sounds effects module, the selections it provides, etc. Covers 34 and 36 typically
enclose a printed circuit board with the sound effects device or devices and any
supporting circuitry required thereon in a manner to seal the same from both the
volume within the sound effects module and the exterior thereof.
In general, the sealing of the various components making up the module will be
by way of o-rings or other elastic seals. For those components which do not need to be
disassembled for any reason, alternate assembly techniques, such as ultrasonic welding,
solvent welding, or the like could be used. In any event, the output of the electronics
generating the sound signal is coupled to the actuator 50 of the mylar speaker 26
through leads not shown, with leads 38 being connected to the trigger switch for
turning on the sound effects module when the trigger of the water gun is pulled. The
leads 38 extending through the housing 24 to the trigger switch may be sealed by a
silicon seal 37 and provided with a strain relief 39. These basic components, shown in
exemplary embodiment form, are in one way or another common to all four exemplary
embodiments of Figures 2a-2g, 3a-3g, 4a-4g, and 5a-5g.
In the embodiment of Figures 2a-2g, small holes 40 are provided through the
lower wall of the module housing 24 to allow the interior volume of the sound effects
module (other than the compartments sealed by covers 34 and 36) to breathe, allowing
the internal pressure within the greater volume of the sound effects module 22 to equal
atmospheric pressure. In that regard, it is important that that interior chamber be at or
near the outside ambient pressure, as otherwise the speaker cone 52 of the mylar
speaker 26 will have a pressure differential there across, providing a stress on the
speaker cone and causing a high degree of distortion in the sound generated, in an
extreme, perhaps even doing permanent damage to the speaker. At normal operating
frequencies of the speaker, however, the holes 40 are too small to allow appreciable
flow, so that the internal volume of the sound effects module will act much like a
sealed chamber, enhancing the output of the speaker at and near the natural frequency
of the speaker/sound effects module air volume.
In the embodiment of Figures 3a-3g, specifically as shown in Figure 3e, a pair
of one-way valves 300 is provided which prevents the buildup of pressure within the
sound effects module housing, though prevents water from entering the housing. A
hole 302 in the housing 24 allows pressure within the sound effects module to be
equalized through the pair of one-way valves 300. Various types of one way valves
300 could be used, such as, by way of example, duck bill rubber valves or ball check
valves. Such an embodiment would block water flow into the interior of the module,
but tend to allow air flow into and out of the interior region. The one way valves are
arranged so that one valve allows air to flow into the chamber and the other valve
allows air to flow out of the chamber. These valves operate in concert to maintain the
pressure of the internal compression chamber at equilibrium with atmospheric pressure.
In the embodiment of Figures 4a-4g, as specifically shown in Figure 4e, a hole
400 is provided through the case with a semipermeable filter member 402 mounted
therein to allow the passage of air, but not the passage of water, into and out of the
interior volume of the sound effects module. The air flow through such a
semipermeable filter of the various types as are well known is fairly restricted, so as to
have no significant effect on the acoustic properties of the system at the desired
frequencies of the sound effects generated by the speaker.
In the embodiment shown in Figures 5a-5g, specifically Figures 5b and 5e,
expansion and contraction of the air within the sound effects module is compensated
for by the flexibility of the module housing 24 itself, specifically by the imposition of
an accordion type flexible member 42, sealed with respect to the module housing 24
and end member 44. A restriction plate 46 in this embodiment closes off most of the
end of module housing 24 to define the internal volume of air behind the speaker for
acoustic purposes, with a small hole 54 in member 46 allowing very low frequency
breathing between the volume behind the speaker cone 52 and the volume enclosed by
the flexible member 42 to equalize pressures there between. Thus this embodiment,
like the others, maintains the acoustic characteristics of the mylar speaker/air chamber
there behind, while at the same time, provides even better water resistance for the
sound effects module.
Figures 5a-5f illustrate the flexible member 42, the restriction plate 46, the end
member 44, a seal plate 510 and a cover 512. To assemble the flexible member 42 to
the module housing 24, the flexible member 42 is presented at the end of the module
housing 24. A skirt 506 of the flexible member 42 is fitted over the lip 508 of the
module housing 24. The skirt 506 may be made from an elastomeric material. A
restriction plate 46 is slid into the other end of the module housing 24. The restriction
plate 46 is then screwed into the end of the module housing 24 thereby capturing and
compressing the skirt 506. Thus the skirt 506 seals the flexible member 42 and the
module housing 24. The end member 44 is presented to the flexible member 42. A
seal similar to the module housing 24 and flexible member 42 may be formed between
the end member 44 and flexible member 42 using the seal plate 510. A cover 512 with
battery case 30 and removable battery door 32 is sealed to the end member 44.
In another embodiment, the restriction plate may have a tongue 502 and the
module housing 24 may have a groove 504. Restriction plate 46 is pushed toward the
accordion end of the module housing so that tongue 502 engages groove 504. Thus the
tongue 502 and groove 504 capture and compress the skirt 506 to seal the flexible
member 42 and the module housing 24. In another embodiment, the flexible member
42 is coupled to module housing 24 by ultrasonic welding, solvent welding or the like.
In the embodiments described herein, the basic sound effects generation has
been described with respect to some form of electronic sound effects generator. Other
types of sound effects generation and effects of other types may also be generated by
the water resistant module of the present invention. By way of example, the sound
effects module might have mounted therein a motor with an eccentric weight to
introduce a vibration instead of, or in addition to, the sound effects, the eccentric
weight simulating the recoil of a machine gun type device. As a further alternative, the
eccentric weight might be comprised of one or more washer type rings on an eccentric
pin, positioned to intercept a rigid wall or end of the sound effects chamber, so as to
create a firing noise every time the washer or washers strike the end wall on each
rotation of the eccentric, thus generating both the desired noise and vibration from the
same device. Other alternatives may include lights, pumps or other devices protected
within the water resistant module. These and other alternate embodiments will be
apparent to those skilled in the art. Thus, while the present invention has been
disclosed and described with respect to certain specific embodiments thereof, it will be
understood by those skilled in the art that various changes in form and detail may be
made therein without departing from the spirit and scope of the invention.