U.S. patent application number 09/735700 was filed with the patent office on 2001-06-28 for forced ventilation system for electric instruments.
Invention is credited to Iwasaki, Shizuo.
Application Number | 20010005309 09/735700 |
Document ID | / |
Family ID | 26581730 |
Filed Date | 2001-06-28 |
United States Patent
Application |
20010005309 |
Kind Code |
A1 |
Iwasaki, Shizuo |
June 28, 2001 |
Forced ventilation system for electric instruments
Abstract
An audio system component is disclosed which has a boxlike
casing partitioned into an air intake passageway extending along
one side of the casing, an exhaust passageway extending along the
other side, and a circuit chamber between the two passageways. Both
passageways are open rearwardly of the casing. A cooling fan is
mounted in the circuit chamber for causing airflow from the intake
to the exhaust passageway through the circuit chamber. The electric
circuitry of the instrument, possibly including electronic
components that need cooling, is housed in the circuit chamber so
as to be cooled by the airflow. The circuitry has terminals
arranged on the back of the casing and between the open ends of the
air passageways.
Inventors: |
Iwasaki, Shizuo;
(Takorozawa-shi, JP) |
Correspondence
Address: |
WOODCOCK WASHBURN KURTZ
MACKIEWICZ & NORRIS LLP
46th Floor
One Liberty Place
Philadelphia
PA
19103
US
|
Family ID: |
26581730 |
Appl. No.: |
09/735700 |
Filed: |
December 13, 2000 |
Current U.S.
Class: |
361/695 ;
361/688 |
Current CPC
Class: |
H05K 7/20145
20130101 |
Class at
Publication: |
361/695 ;
361/688 |
International
Class: |
H05K 007/20 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 24, 1999 |
JP |
11-366082 |
Sep 22, 2000 |
JP |
2000-289511 |
Claims
What is claimed is:
1. A ventilated electric instrument comprising: (a) a casing having
formed therein an air intake port and an exhaust port; (b) a fan
mounted interiorly of the casing for causing airflow therethrough
from the intake port to the exhaust port; (c) electric circuit
means mounted interiorly of the casing and positioned to be cooled
by the airflow; and (d) terminal means mounted exteriorly of the
casing and electrically connected to the electric circuit
means.
2. The ventilated electric instrument of claim 1 wherein the casing
is boxlike in shape, having a top, a bottom, a pair of opposite
faces, and a pair of opposite sides, wherein the intake port and
the exhaust port are both formed in spaced positions on one of the
opposite faces of the casing, and wherein the terminal means is
disposed between the intake port and the exhaust port.
3. A ventilated electric instrument comprising: (a) a casing of
substantially boxlike shape having a top, a bottom, a pair of
opposite faces, and a pair of opposite sides; (b) partition means
within the casing defining therein an air intake passageway
extending along one side of the casing, an exhaust passageway
extending along the other side of the casing, and a circuit chamber
between the intake and the exhaust passageways; (c) a fan mounted
interiorly of the casing for causing airflow from the intake
passageway to the exhaust passageway through the circuit chamber;
(d) electric circuit means mounted in the circuit chamber of the
casing and positioned to be cooled by the airflow; and (e) terminal
means arranged on one of the faces of the casing and electrically
connected to the electric circuit means.
4. The ventilated electric instrument of claim 3 wherein the
partition means comprises: (a) a first partition extending along
said one side of the casing for defining the intake passageway, the
first partition having formed therein an opening for air inflow
from the intake passageway to the circuit chamber; and (b) a second
partition extending along said other side of the casing for
defining the exhaust passageway, the second partition having formed
therein a second opening for air outflow from the circuit chamber
to the exhaust passageway.
5. The ventilated electric instrument of claim 4 wherein the fan is
mounted to the first partition and aligned with the air inflow
opening therein for drawing air from the intake passageway into the
circuit chamber.
6. The ventilated electric instrument of claim 4 wherein the fan is
mounted to the second partition and aligned with the air outflow
opening therein for exhausting air from the circuit chamber into
the exhaust passageway.
7. The ventilated electric instrument of claim 4 wherein the intake
passageway and the exhaust passageway are open through an intake
port and an exhaust port, respectively, which are formed in said
one face of the casing.
8. The ventilated electric instrument of claim 7 wherein the air
inflow opening in the first partition and the air outflow opening
in the second partition are both disposed closer to the other face
of the casing than to said one face thereof.
9. A ventilated electric instrument comprising: (a) a casing bottom
part substantially in the shape of an open-top box integrally
comprising a bottom panel, a pair of opposite face panels, and a
pair of opposite partition panels; (b) a casing top part
substantially in the shape of an inverted U integrally comprising a
top panel, which closes the open-top of the casing bottom part and
which defines in combination therewith a circuit chamber between
the pair of partition panels of the casing bottom part, and a pair
of opposite side panels depending from the top panel to define in
combination with the partition panels of the casing bottom part an
air intake passageway and an exhaust passageway on opposite sides
of the circuit chamber; (c) a fan mounted in the circuit chamber
for causing airflow from the intake passageway to the exhaust
passageway through the circuit chamber; (d) electric circuit means
mounted in the circuit chamber and positioned to be cooled by the
airflow; and (e) terminal means arranged on one of the face panels
of the casing bottom part and electrically connected to the
electric circuit means.
10. The ventilated electric instrument of claim 9 wherein the other
face panel of the casing bottom part have portions extending beyond
the partition panels for closing the intake passageway and the
exhaust passageway.
11. The ventilated electric instrument of claim 9 wherein the
casing top part further comprises a pair of flange panels formed
respectively on the pair of side panels for forming the bottoms of
the intake passageway and the exhaust passageway.
12. A ventilated electric instrument comprising: (a) a casing
bottom part substantially in the shape of an open-top box
integrally comprising a bottom panel, a pair of face panels erected
from two opposite sides of the bottom panel, a pair of partition
panels erected from two other opposite sides of the bottom panel,
and a pair of top flanges formed one on each partition panel; (b) a
casing top part substantially in the shape of an inverted U
integrally comprising a top panel, which closes the open-top of the
casing bottom part and which defines in combination therewith a
circuit chamber between the pair of partition panels of the casing
bottom part, a pair of opposite side panels depending from the top
panel to define in combination with the partition panels of the
casing bottom part an air intake passageway and an exhaust
passageway on opposite sides of the circuit chamber, and a pair of
bottom flanges formed one on each side panel to provide bottoms of
the intake passageway and the exhaust passageway; (c) first
fastener means for fastening the top panel of the casing top part
to the pair of top flanges of the casing bottom part; (d) second
fastener means for fastening the bottom flanges of the casing top
part to the bottom panel of the casing bottom part; (e) a fan
mounted in the circuit chamber for causing airflow from the intake
passageway to the exhaust passageway through the circuit chamber;
(f) electric circuit means mounted in the circuit chamber and
positioned to be cooled by the airflow; and (g) terminal means
arranged on one of the face panels of the casing bottom part and
electrically connected to the electric circuit means.
13. The ventilated electric instrument of claim 12 wherein the
other face panel of the casing bottom part have portions extending
beyond the partition panels for closing the intake passageway and
the exhaust passageway.
14. The ventilated electric instrument of claim 12 wherein the pair
of bottom flanges of the casing top part are in underlapping
relationship to the bottom panel of the casing bottom part.
Description
BACKGROUND OF THE INVENTION
[0001] This invention relates to some improvements in a forced
ventilation system for those electric instruments which have
electric circuit means that need ventilation, such as semiconductor
devices on printed circuit boards, or to such an electric
instrument incorporating the improved forced ventilation
system.
[0002] Electric instruments with a generally boxlike casing have
been known and used extensively which have an exhaust fan mounted
outside the casing. The air heated by the electronic devices within
the casing is drawn by the fan and forced out of the casing in
order to keep the devices at operable temperatures.
[0003] Being required to be least conspicuous, the fan has usually
been mounted on the back of the casing. This fan location has
brought about some inconveniences. First, in cases where a
multiplicity of terminals are to be arranged on the back of the
casing, the fan with its relatively large space requirement has
imposed limits upon the latitude of terminal arrangement. Another
pronounced inconvenience has been the noise produced by the more or
less exposed fan.
[0004] There are additional considerations that must enter into the
design of a well-ventilated electric instrument, particularly its
casing. There must be an optimum airflow through the interior of
the casing for most efficient cooling of the components housed
therein. The constituent parts of the casing, well designed to
assure such airflow, must, moreover, not add substantially to the
manufacturing costs of the instrument and must lend themselves to
ready assemblage.
SUMMARY OF THE INVENTION
[0005] The present invention has it as an object to provide a well
ventilated electric instrument having a cooling fan incorporated
therein so as not to interfere in any way with a desired
arrangement of terminals or the like on its casing.
[0006] Another object of the invention is to reduce noise
production by the fan to a minimum.
[0007] Still another object of the invention is to assure optimum
airflow through the interior of the casing for most efficient
cooling of the components housed therein.
[0008] A further object of the invention is to facilitate the
manufacture and assemblage of the instrument that accomplishes all
the foregoing objects.
[0009] Stated briefly, the present invention concerns a ventilated
electric instrument comprising a casing having formed therein an
air intake port and an exhaust port. A fan is mounted interiorly of
the casing for causing airflow therethrough from the intake port to
the exhaust port. Electronic circuit means are mounted interiorly
of the casing and positioned to be cooled by the airflow, and
terminal means are mounted exteriorly of the casing and
electrically connected to the electronic circuit means.
[0010] Thus, with the fan mounted inside the casing, and preferably
away from the back of the casing, terminals or the like can be
arranged over a greater area on the casing back, in an ideal
pattern or in a greater number than if the fan were mounted to the
casing back. Noise production by the fan is also reduced to a
minimum.
[0011] According to another feature of the invention, the casing
has its interior partitioned into an air intake passageway
extending along one side of the casing, an exhaust passageway
extending along the other side of the casing, and a circuit chamber
between the intake and the exhaust passageways. The electric
circuit means are mounted in the circuit chamber.
[0012] Preferably, both air passageways are open rearwardly of the
casing to the atmosphere and closed at their front ends, besides
being open to the circuit chamber via inflow and outflow openings
in the partitions. These openings in the partitions may be situated
closer to the closed front ends, than to the open ends, of the air
passageways.
[0013] Lying in the circuit chamber, the fan is mounted to the
partition bounding the intake passageway in one embodiment of the
invention, and to the other partition bounding the exhaust
passageway in another. Either way, ambient air is drawn into the
circuit chamber via the intake passageway on one side of the casing
and exhausted therefrom via the exhaust passageway on the other
side of the casing.
[0014] The electric circuit means will be cooled most efficiently
by being positioned in the flow path of the air through the circuit
chamber. The casing itself will also be cooled efficiently as the
air streams into the circuit chamber not directly but via the
elongate intake passageway and flows out not directly but via the
elongate exhaust passageway.
[0015] No less significant advantage accruing from the provision of
the intake and exhaust passageways is that the circuit chamber is
completely closed except for the openings in the partitions. The
fan will therefore present little or no noise problem.
[0016] According to a further feature of the invention, the casing
is constituted of two parts which are designed for ease of
fabrication and assemblage and which, moreover, are well calculated
to realize all the foregoing features and advantages of the
invention. The two parts of the casing are a casing bottom part
substantially in the shape of an open-top box, and a casing top
part substantially in the shape of an inverted U as seen in the
depth direction of the casing. Both casing parts are manufacturable
by bending required parts of sheet-metal punchings, and assemblable
by interengaging them and fastening them with a minimal number of
screws or the like.
[0017] The above and other objects, features and advantages of the
invention and the manner of realizing them will become more
apparent, and the invention itself will best be understood, from
the following description taken together with the attached drawings
showing the preferred embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 is a perspective view of an example of ventilated
electric instrument embodying the principles of the present
invention, the instrument being herein shown as seen from its
front;
[0019] FIG. 2 is a view similar to FIG. 1 except that the
instrument is shown as seen from its rear;
[0020] FIG. 3 is a top plan of the FIG. 1 instrument;
[0021] FIG. 4 is a rear elevation of the FIG. 1 instrument;
[0022] FIG. 5 is a vertical section through the FIG. 1 instrument,
taken along the line A-A in FIG. 3;
[0023] FIG. 6 is another vertical section through the FIG. 1
instrument, taken along the line B-B in FIG. 3;
[0024] FIG. 7 is an exploded perspective view of the FIG. 1
instrument, showing in particular the detailed constructions of the
top part and bottom part of the casing; and
[0025] FIG. 8 is a view similar to FIG. 3 but showing an
alternative embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0026] The invention will now be described in detail as embodied in
a component in a component audio system for interconnection and
signal relaying of the various other components. As will be
understood from both FIGS. 1 and 2, the exemplified electric
instrument 1 broadly comprises a casing 2 having electric circuit
means 3 housed therein, a cooling fan 4 mounted interiorly of the
casing, a power switch 5 on one face of the casing, and a set of
terminals 6 and power outlets or receptacles 7 on the opposite face
of the casing. The casing 2 is pictured in both FIGS. 1 and 2 with
the thickness of the sheet metal of which the casing is made,
disregarded.
[0027] Although not shown in detail because of irrelevance to the
invention, the electric circuit means 3 are understood to have
semiconductor devices, capacitors, resistors and so forth mounted
on a printed circuit board. Such circuit means are electrically
connected to the terminals 6. The cooling fan 4 is electrically
connected to a power supply, not shown, via the power switch 5, so
that the fan starts working automatically as the instrument 1 is
switched on. The receptacles 7 are also connected to the unshown
power supply, either directly or via the power switch 5, for
powering other system components.
[0028] FIG. 1 depicts the instrument 1 in the correct attitude in
which it is to be put to use. The directional terms such as "front"
and "rear," "top" and "bottom," and "righthand" and "lefthand" will
be used hereinafter in this specification in reference to this
attitude of the instrument in mind, unless otherwise specified.
[0029] Thus, as will be noted from all of FIGS. 1-6, the casing 2
is of relatively flat, boxklike shape having a relatively broad top
8, a bottom 9 of the same shape and size as the top, a front 10 of
a greater horizontal dimension than a vertical, with the power
switch 5 adjacent its lefthand end, a back 11 parallel to the
front, with the terminals 6 and 7 arranged intermediate the
opposite ends thereof, a lefthand side 12 which is also elongated
horizontally but to a somewhat lesser extent than are the front and
the back, and a righthand side 13 of the same shape and size as the
lefthand side. The terminals 6 on the back 11 of the casing 2 are
shown in FIGS. 2 and 4 as pin connector halves, with which the
other connector halves, not shown, are to be engaged for connection
of other system components.
[0030] Formed at the opposite ends of the back 11 are a slotlike
air intake port 14 and exhaust port 15. The terminal pins 6 and
receptacles 7 are disposed between these ports 14 and 15.
[0031] Perhaps as best revealed by FIG. 3, the interior of the
casing 2 is divided into an air intake passageway 16 extending
along the lefthand side 12 of the casing, an exhaust passageway 17
extending along the righthand side 13 of the casing, and a circuit
chamber 18 between these passageways for accommodating the electric
circuit means 3. The intake passageway 16 is open rearwardly
through the intake port 14 and has its front end closed. The
exhaust passageway 17 is likewise open rearwardly through the
exhaust port 15 and has its front end closed. The circuit chamber
18 is completely enclosed except for air inflow and outflow
openings to be set forth presently.
[0032] Preferably, and as shown in exploded perspective in FIG. 7,
the casing 2, having its interior partitioned into three sections
as above, should take in practice the form of a combination of a
bottom part 19 and a top part 20. The casing bottom part 19 is
substantially in the shape of an open-top box. The casing top part
20 is in the shape of an inverted U as seen in front or rear
elevation, closing the open top of the casing bottom part 19. These
casing parts 19 and 20 are well calculated to permit fabrication by
simple bending of sheet-metal punchings and, further, assemblage
with use of a minimum number of screws or like fastener elements,
as will become better understood as the description progresses.
[0033] More specifically, the casing bottom part 19 is a one-piece
construction of a bottom panel 21, a front panel 22, a rear panel
23, and a pair of partition panels 24 and 25. The bottom panel 21
is of rectangular shape, and the other panels 22, 23, 24 and 25 are
all bent right-angularly up from the four sides of the bottom
panel. Constituting a major part, not all, of the bottom 9 of the
FIGS. 1-6 casing 2, the bottom panel 21 is shown to have the
electric circuit means 3 mounted approximately centrally
thereon.
[0034] The front panel 22 of the casing bottom part 19, forming the
front 10 of the FIGS. 1-6 casing 2, is shown with the power switch
5 thereon. This front panel 22 is of greater horizontal dimension
than the rear panel 23 of the body part 19, or the distance between
the pair of partition panels 24 and 25, having a pair of opposite
end portions extending beyond these side panels for closing the
front ends of the air passageways 16 and 17, shown for example in
FIG. 3, which are to be defined by the casing bottom part 19 and
casing top part 20 when these are put together in a manner yet to
be described.
[0035] The rear panel 23 of the casing bottom part 19 provides the
back 11, FIG. 2, of the casing 2. Although the rear panel 23 is
shown as a blank piece of sheet metal in FIG. 7, it is understood
that the terminal pins 6 and receptacles 7 are to be provided on
this rear panel, which therefore is in need of perforation for
mounting such means.
[0036] The pair of partition panels 24 and 25 of the casing bottom
part 19 are opposite each other and at right angles with the front
panel 22 and rear panel 23. As indicated in FIG. 3, the lefthand
partition panel 24 serves as the partition between the air intake
passageway 16 and the circuit chamber 18 of the FIGS. 1-6 casing 2
and the righthand partition panel 25 as the partition between the
air exhaust passageway 17 and the circuit chamber 18.
[0037] With reference to both FIGS. 3 and 7, an opening 26 of
circular shape is cut in the lefthand partition panel 24 for air
inflow from the intake passageway 16 into the circuit chamber 18,
and another similar opening 27 in the righthand partition panel 24
for air outflow from the circuit chamber 18 into the exhaust
passageway 17. It will be noted that both openings 26 and 27 are
situated closer to the front of the casing 2, where the passageways
16 and 17 are closed, than to the rear of the casing, where they
are open, for most efficient cooling of the entire casing and its
interior, not to mention the electric circuit means 3 in the
circuit chamber 18.
[0038] FIG. 7 shows flanges 28 and 29 bent right-angularly from the
tops of the partition panels 24 and 25, respectively, and extending
toward each other. A plurality of, two in the illustrated
embodiment, tapped holes 31 are formed in each top flange 28 or 29,
for use in screwing the cover part 20 to the body part 19.
Additional tapped holes are formed at 33 in the bottom panel 21
also for use in fastening the cover part to the body part.
[0039] The casing top part 20 is a one-piece construction of a top
panel 34, a pair of opposite side panels 35 and 36, and a pair of
bottom flanges 37 and 38. The top panel 34 is of rectangular shape,
and the pair of side panels 35 and 36 are both bent right-angularly
down from the opposite sides of the top panel. The pair of bottom
flanges 37 and 38 are further bent right-angularly, and toward each
other, from the bottom edges of the side panels 35 and 36.
[0040] As indicated also in FIG. 7, aside from the foregoing
mechanical makeup thereof, the casing top part 20 may be
functionally divided into a midportion 20a forming a part of the
means defining the circuit chamber 18, and a pair of opposite end
portions 20b and 20c forming parts of the means defining the air
passageways 16 and 17, respectively. The portion 20a occupies most
of the top panel 34, closing the open top of the body part 19. The
rest of the casing top part 20 are the portions 20 b and 20c.
[0041] The top panel 34 of the casing top part 20 provides the top
8 of the FIGS. 1-6 casing 2. The side-to-side dimension of the top
panel 34 is therefore greater than that of the bottom panel 21 of
the body part 19 and approximately equal to that of the front panel
22 of the body part. Clearance holes are formed at 39 through the
top panel 34 for the passage of screws 30 as they are driven into
the noted tapped holes 31 in the top flanges 28 and 29 on the
partition panels 24 and 25 of the casing bottom part 19.
[0042] The pair of side panels 35 and 36 of the casing top part 20
form the pair of opposite sides 12 and 13 of the FIGS. 1-6 casing
2, or the outer walls of the air passageways 16 and 17. However, as
clearly revealed by FIGS. 5 and 6 in particular, these side panels
35 and 36 are made somewhat greater in height than the pair of
partition panels 24 and 25 of the casing bottom part 19, which are
the inside walls of the air passageways 16 and 17, for reasons made
apparent below.
[0043] The pair of bottom flanges 37 and 38 of the casing top part
20 form parts of the bottom 9 of the FIGS. 1-6 casing 2 and,
specifically, the bottoms of the air passageways 16 and 17.
However, with reference to FIGS. 5 and 6 again, the bottom flanges
37 and 38 are of greater width than the air passageways 16 and 17.
The pair of side panels 35 and 36 of the casing top part 20 are
made greater in height than the pair of partition panels 24 and 25
of the body part 19, as aforesaid, only to such an extent that when
the body part and the cover part are assembled as in these figures,
the pair of bottom flanges 37 and 38 come into underlapping
relationship to the bottom panel 21 of the body part. Clearance
holes are formed at 40 through the underlapping parts of the bottom
flanges 37 and 38 for the passage of screws 32 as they are turned
into the aforesaid tapped holes 33 in the bottom panel 21 of the
casing bottom part 19.
[0044] It is now seen that the circuit chamber 18 is defined both
by the bottom panel 21, part of the front panel 22, the rear panel
23, and the partition panels 24 and 25 of the casing bottom part 19
and by part of the top panel 34 of the casing top part 20. The air
intake passageway 16 is defined both by the side panel 35, bottom
flange 37, and part of the top panel 34, of the casing top part 20
and by the partition panel 24 and part of the front panel 22 of the
casing bottom part 19. The exhaust passageway 17 is defined both by
the side panel 36, bottom flange 38, and part of the top panel 34,
of the casing top part 20 and by the partition panel 25 and part of
the front panel 22 of the casing bottom part 19.
[0045] As depicted in phantom outline in FIG. 3, the cooling fan 4
comprises a set of revolving vanes 4a and an electric drive motor
4b. The fan 4 is to be mounted inside the lefthand partition panel
24 of the body part 19, and in alignment with the air inflow
opening 26 therein, before the casing top part 20 is placed upon
the casing bottom part. Also prior to the assemblage of the casing
parts 19 and 20, the electric circuit means 3 may be mounted in
position on the bottom panel 21 of the body part 19.
[0046] Then the casing bottom part 19 and casing top part 20 may be
put together by inserting, the rear panel 23 foremost, the opposite
lateral end portions of the casing bottom part into the spaces
between the top panel 34 and bottom flanges 37 and 38 of the casing
top part. Then screws 30 may be driven through the clearance holes
39 in the casing top part top panel 34 into the tapped holes 31 in
the casing body part partition flanges 31, and screws 32 through
the clearance holes 40 in the casing top part bottom flanges 37 and
38 into the tapped holes 33 in the casing bottom part bottom panel
21.
[0047] The assemblage of the instrument 1 is completed by turning
only the total of eight screws 30 and 32, in this embodiment of the
invention. It will be appreciated that the casing bottom part 19
and casing top part 20 are shaped in intercomplementary
relationship to each other to define in combination not only the
circuit chamber 18 but the pair of air passageways 16 and 17 as
well. These three discrete spaces are automatically created simply
as the two casing parts 19 and 20 are combined as above.
[0048] In use of the instrument 1 the fan 4 is to be driven in a
direction for drawing air into the circuit chamber 18. The ambient
air will be drawn into the intake passageway 16 through the intake
port 14 at the back of the casing 2, thence into the circuit
chamber 18 through the inflow opening 26 in the partition 24,
thence into the exhaust passageway 17 through the outflow opening
27 in the partition 25, and out of the casing through the exhaust
port 15 at the back of the casing. The cooling of the electric
circuit means 3 is accomplished by the forced current of air
through the circuit chamber 18.
[0049] The advantages gained by the foregoing embodiment of the
invention may be recapitulated as follows:
[0050] 1. With the fan 4 mounted inside the casing 2, and spaced a
considerable distance away from the back 11 of the casing, the
terminal pins 6 and receptacles 7 can be arranged as desired all
over the back of the casing.
[0051] 2. Thanks to the absence of the fan 4 from the casing back
11, and the presence of only the air intake port 14 and exhaust
port 15, a sufficiently large area is secured on the casing back
for the provision of a desired number of terminal pins 6 and
receptacles 7, and in an arrangement convenient for connection of
other instruments by the user.
[0052] 3. The arrangement of the terminal pins 6 and receptacles 7
solely on the casing back 11 makes the instrument 1 esthetically
appealing as seen from the front.
[0053] 4. Less audible noise is produced by confining the fan 4
within the casing 2.
[0054] 5. An ideal flow path of cooling air is defined within the
casing by the pair of partitions 24 and 25 therein for most
efficient cooling of the electric circuit means 3.
[0055] 6. The division of the casing interior into the three spaces
16, 17 and 18 is accomplished by the combination of only the two
casing parts 19 and 20.
[0056] 7. The casing parts 19 and 20 are well designed for ease of
fabrication and ease of assemblage.
[0057] The FIGS. 1-7 instrument 1 may be modified as shown in FIG.
8 and therein generally designated 1a. The modified instrument 1a
has the casing 1 of exactly the same construction as that of the
foregoing embodiment; only, the cooling fan 4 is mounted to the
righthand partition 25, in a position just upstream of the exhaust
opening 27 therein. The fan 4 is to be driven in a direction for
exhausting the air from the circuit chamber 18 into the exhaust
passageway 17. Fresh ambient air will be taken in through the
intake port 14 into the intake passageway 16 and thence into the
circuit chamber 18 through the inflow opening 26 in the partition
24, just as in the first disclosed embodiment.
[0058] Notwithstanding the foregoing detailed disclosure, it is not
desired that the present invention be limited by the exact showing
of the drawings or the description thereof. For example, the front
ends of the air passageways 16 and 17 could be left open. Further
the invention itself could be applied to a variety of electric
instruments other than the exemplified audio system component.
These and other modifications, alterations, or adaptations of the
illustrated embodiments will suggest themselves to one skilled in
the art without departure from the scope of the claims attached
hereto.
* * * * *