A flexible sound-absorbent blower cover includes an outer skin of a pliable material shaped to surround the blower and conforming generally to the shape of the blower but oversize to provide a space between the outer skin and the blower. A flexible porous sound-absorbent liner is disposed in the space and is bonded to the outer skin. The blower draws air in through the liner which filters the air. The structure of the flexible one piece cover prevents it from resonating. The cover is provided with a slit which can be opened to facilitate installation and then closed to keep the cover in place on the blower.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention is in the field of swimming pool equipment and more 
particularly relates to a sound-absorbent cover for a blower of the type 
used to supply air to a spa. 
2. The Prior Art 
Most spas are provided with an air blower for introducing a stream of air 
into the water as it is injected into the spa. Blowers currently on the 
market are built in the form of an upright cylinder approximately 9 inches 
in diameter and approximately 9 inches high. The blower normally is 
provided with an air intake opening, and further includes an electric 
motor which drives an air impellor which forces the air out of the blower 
through an outlet duct which conducts the air into the spa. Such blowers 
are designed for high performance and the working parts are enclosed 
within a housing which is designed to prevent tampering and to keep out 
water. Typically, the housing includes an electrical connection for 
powering the blower, and typically, the outlet duct extends downward 
beneath the blower which may be mounted a foot or so off the ground on 
legs. 
Enough people find the blowers described above to be noisy that a market 
exists for an add-on muffling cover. The primary requirement of such a 
cover is that it be capable of muffling the sound. In addition, it must 
not adversely affect the flow of air into the blower, it should be 
inexpensive to manufacture, and it should be easy to install on existing 
blowers. 
To the extent that the sound-absorbent material does not cover the air 
intake aperture of the blower, the noise reducing cover will be 
inefficient. On the other hand, if the air intake aperture is covered by 
the sound-absorbent material, the air cannot freely be drawn into the 
blower and as a result, the motor will overheat and burn out. As will be 
seen below, the present invention provides a simple and effective solution 
to this dilemma. 
In one noise reducer known to be on the market, the blower is enclosed in a 
rigid inverted can and the can is closed at the bottom by screwing to it a 
rigid bottom which is supplied in two halves, the latter being brought 
into position from the side to surround the downwardly extending outlet 
duct, and being attached to the inverted can by a flange around the edges 
of the halves. A number of problems are implicit in such a design. Because 
the can is rigid it is capable of resonating at some of the frequencies 
present in the noise generated by the blower and, therefore, its muffling 
efficiency might be reduced. Further, the rigid halves forming the bottom 
of the can may vibrate against the can or against portions of the blower 
to generate noise. It is also possible that the screws holding the bottom 
of the can might vibrate loose. As will be seen below, the present 
invention eliminates these potential problem areas by use of an entirely 
different design approach. 
SUMMARY OF THE INVENTION 
Resonance and vibration of the parts of the cover are eliminated by the 
structure of the present invention, in which the entire cover consists of 
pliable materials. Specifically, in the present invention, the cover 
includes an outer skin of a pliable material having a shape similar to the 
shape of the blower, but oversize so that sound-absorbent material can be 
disposed between the outer skin and the blower. 
In the present invention, the sound-absorbent material is a flexible porous 
substance such as a plastic foam, and the sound-absorbent material is 
disposed in such a manner that some of the air taken in by the blower 
passes through the sound absorbent material before reaching the air intake 
so that the air is filtered to some extent by the sound-absorbent 
material. In this manner, sound emanating from the air intake of the 
blower is muffled without unduly interfering with the free flow of air 
into the air intake aperture. 
In a preferred embodiment, the sound-absorbent liner material is bonded to 
the outer skin of the cover. 
In a preferred embodiment of the present invention, the cover has a 
cylindrical shape and includes a slit up one side to permit it to be 
installed easily. After installation, the slit is closed by a fastener. 
One cover now on the market includes three separate pieces which must be 
screwed together, thereby requiring five minutes for installation and the 
use of a special tool. In contrast, the cover of the present invention can 
be installed in a matter of seconds without the need for any tools. 
Because the cover of the present invention is a single composite 
structure, there are no parts which can vibrate loose and fall off. 
The novel features which characterize the invention, both as to its 
structure and method of installation and operation, together with further 
object and advantages will be better understood from the following 
description considered in connection with the accompanying drawings in 
which a preferred embodiment of the invention is illustrated by way of 
example. It is to be expressly understood, however, that the drawings are 
for the purpose of illustration and description and are not intended as a 
definition of the limits of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
Turning now to the drawings in which like parts are denoted by the same 
reference numeral, there is shown in FIG. 1 an exploded perspective view 
of the cover 10 of the present invention which is designed to fit over and 
surround the blower 30. The cover 10 includes an outer skin 12 of a 
pliable material. The outer skin 12 has a shape which permits it to be 
slipped over the blower 30. In a preferred embodiment, the outer skin, 
while conforming in shape generally to the shape of the blower 30, is 
sized to fit the blower rather loosely so that a space remains between the 
outer skin and the body 32 of the blower when the cover is installed on 
the blower. In accordance with the present invention, the space between 
the cover 10 and the blower 30 is partially filled by a sound-absorbent 
flexible liner material 14. In one embodiment, the liner material 14 
includes separate pieces 16 of liner material disposed within the space to 
form air passages 18 between the separate pieces 16 through which air will 
be drawn to the air intake aperture 40 of the blower. In another 
embodiment, the porous material 14 consists of a unitary piece of liner 
material through which the air is drawn. In a preferred embodiment, the 
liner material is a flexible porous sound absorbing material such as 
plastic foam of the open cell type. 
In a preferred embodiment, the outer skin 12 is a waterproof, pliable 
material such as vinyl or treated cloth. 
In a preferred embodiment, the liner material 14 is bonded to the inner 
surface of the outer skin 12 so as to be affixed to it. 
In a preferred embodiment, the cover 10 includes a fly 20 which is a 
closable slit concealed beneath a flap. The fly 20 is held closed when the 
cover has been installed by means of the fastener 22. 
The cover 10 of the present invention is especially easy to install; 
installing it is similar to putting on a pair of pants. With the fly 20 
open, the cover 10 is pulled over the blower 30, and then the fastener 22 
is closed, completing the installation in a matter of a few seconds. In 
one embodiment, an aperture 44 is provided to permit the junction box 42 
to extend through the cover. 
In one embodiment of the present invention, several auxiliary air passages 
24 are provided to facilitate the entry of air. The auxiliary air passages 
24 are protected by grommets 26. 
Typically, the blower 30 includes a rigid body 32 which may be made of 
plastic, the legs 36 which support the blower 30 above the ground 34, an 
outlet duct 28 for the air, an air intake aperture through which the air 
is drawn into the blower, and an electrical junction box 42 in which the 
electrical wires in the conduit 38 are connected to the blower motor 
leads. 
Clearly, the cover 10 of the present invention is not limited to use with 
blowers of the configuration shown. The structural features which 
characterize the present invention are applicable to covers shaped for use 
with blowers of other shapes. For example, the design of a cover for use 
on a cube-shaped blower would be straightforward in view of the disclosure 
given above. Further, it is clear that the cover of the present invention 
in not limited for use with spa blowers, but instead, can be used with 
blowers of other kinds, including without limitation, air conditioning and 
furnace blowers, as well as industrial blowers of various kinds. 
Summarizing, it is seen from the above description that the particular 
advantages of the blower cover of the present invention result from its 
unique structure. Because the cover of the present invention consists 
entirely of flexible material, it is impossible for the cover to resonate 
in response to the noise generated by the blower. The cover consists of a 
single unitary piece, making it impossible for parts of it to vibrate 
against one another. Also, because the cover consists of a single piece, 
it is not necessary to assemble the cover in place on the blower. 
Installation of the cover of the present invention is as simple as putting 
on a pair of pants. The sleeve-like cover is simply pulled over the blower 
and a fly is then closed completing the installation. As a result, the 
cover can be installed in a matter of seconds. 
In a preferred embodiment, all of the air drawn into the blower passes 
through a porous liner material, which filters the incoming air. In a 
preferred embodiment the incoming air passes over an appreciable portion 
of the body of the blower, and this is helpful in warming the air when the 
blower is used in cold ambient temperatures, such as might be encountered 
in ski resorts or in winter. This use of energy which otherwise would be 
wasted helps to reduce the heating requirements of the spa, since the 
latter will be cooled less by the heated air. 
The foregoing detailed description is illustrative of several embodiments 
of the invention but it is to be understood that additional embodiments 
may be obvious to those skilled in the art. The embodiments described 
herein together with those additional embodiments are considered to be 
within the scope of the invention.