FIELD OF INVENTION:
[001] The present invention in general relates to the field of home appliances. The present invention more particularly relates to a mixer-grinder with an improved muffler for reduction of noise. 5
BACKGROUND AND PRIOR ART:
[002] Home appliances such as mixer-grinders are too noisy for home environment. One significant source of noise is the motor that drives the entire unit. This noise is carried by the air that passes through the motor. The main 10 function of this air is to cool the motor.
[003] Indian Patent No. 206887 discloses a mixer grinder which operates at reduced noise level. The airflow interrupter comprises a disc provided across the upper end of the silencer cum guide sleeve above the mounting bracket of the 15 motor assembly, the disc being provided with spaced openings at the periphery thereof associated with arch like airflow obstructing baffles.
[004] Publication No. US6680551 discloses a motor housing assembly including an air exhaust cone for creating laminar air flow, and including an air exhaust 20 passageway for reducing noise created by the operation of the motor.
[005] Publication No. US8579220 discloses a blender including a connection system that lowers the differences of coupling between the appliance base, where the motor is located, and the jar, where the crushing blades are located to be 25 driven by the motor to blend the food. It has used damping material to reduce the audible noise generated due to the vibration of the apparatus. This is achieved by putting the damping system along the power transmission route. The coupling between the base assembly and jar assembly is reducing the vibrations.
30
3
[006] Publication No. EP2709750 is using isolation of the motor housing from any direct connection to the outer shell to reduce or eliminate the noise and vibration. However, it is not using silencer/muffler or any device that reduces the audible noise that is carried by the air flowing on the motor.
5
[007] Publication No. US5696358 discloses an appliance muffling device for reducing noise and vibrations produced by conventional appliances, such as blenders, comprising a uniform cover connectable to a uniform base enclosure both preferably having side walls where a connection is made through snapping engagement so as to form an interior volume for enclosing an appliance, wherein 10 the switch or switches of the appliance are engageable by a slidable switch engaging member assembled on opposite sides of the base side walls through an aperture defined by the base side walls.
[008] Publication No. US5765257 discloses a vacuum cleaner muffler that could 15 be used in other product applications, as may be desired. The muffler body includes a hollow cylindrical section or enlarged head with open opposite ends. A smaller hollow shaft extends within one open end of the hollow cylindrical section and is integrally connected to an inner circumferential wall of the hollow cylindrical section through a series of radially extending fins. 20
[009] Publication No. US2003042805 discloses a muffler incorporated into an electric motor housing to increase air flow across the motor and to reduce noise escaping from the housing.
25
[0010] Publication No. US5004068 discloses a muffler constructed to have a tubular perforated plate within its cavity to divide the cavity into an outer resonant cavity and an inner resonant cavity so as to have two resonant frequencies, the tubular perforated plate being formed in the shape of a funnel.
30
[0011] Publication No. WO2016196271 discloses an appliance including a reverse air flow motor housing. A casing carries and supports a motor, and a ventilation fan is rotated by a rotatable shaft driven by the motor. A lower
4
platform with an air intake port carries a ventilation shroud that partially encloses the ventilation fan.
[0012] Thus, the present invention aims to provide a mixer-grinder with an improved muffler for reduction of noise. 5
OBJECTS OF THE INVENTION:
[0013] The principal objective of the present invention is to provide a mixer-grinder with an improved muffler for reduction of noise.
10
[0014] Another object of the present invention is to provide a mixer-grinder with an improved muffler along with the acoustic material on its inside surface to further reduce the noise.
SUMMARY OF THE INVENTION: 15
[0015] In accordance with the said objectives, the present invention provides a mixer-grinder with an improved muffler for reduction of noise. The muffler is provided along with an acoustic material on its inside surface, to reduce the noise in home appliances such as mixer-grinders. Muffler has a number of sets of baffles placed equidistant to each other to generate a bottle shaped enclosure. 20 Baffles are curved and assembled in a way that air gets trapped in between them. This dead air is used to tune a particular frequency and change the tone of the noise as well.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] It is to be noted, however, that the appended drawings illustrate only 25 typical embodiments of this invention and are therefore not to be considered for limiting of its scope, for the invention may admit to other equally effective embodiments.
[0017] Figure 1 shows side view of the improved muffler according to the present invention. 30
5
[0018] Fig. 2 shows the top view of the improved muffler according to the present invention.
[0019] Figure 3 and 4 show two different possible embodiments of the muffler according to the present invention.
[0020] The figures depict embodiments of the present subject matter for the 5 purposes of illustration only. A person skilled in the art will easily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.
DESCRIPTION OF THE PREFERRED EMBODIMENTS: 10
[0021] The present invention will be described in detail below with reference to an embodiment as shown in the drawing.
[0022] Accordingly the present invention provides a mixer-grinder with an improved muffler along with an acoustic material on its inside surface, to reduce the noise. 15
[0023] Referring to the figure 1, side view of the improved muffler (10) according to the present invention is given. Three sets of baffles (11) are placed equidistant to each other to generate a bottle shaped enclosure (12). Number of sets of said baffles (11) is not considered to be limited to three; it may differ based on the requirement. The gap between said bottle shaped enclosures (12) is a dead volume 20 of air space (13).
[0024] The air in the muffler enters from an air flow inlet (20) and flows on top of said bottle shaped enclosures (12) (shown by the arrows in the figure) and exits from an air flow outlet (25). When outside air flows on top of said bottle shaped 25 enclosures, said dead volume of air (13) provides a resonating effect which helps in tuning the frequency of the audible noise leading to reduction in the overall dB levels.
[0025] Said baffles (11) cover about 50 to 90% of the width of said muffler (10) 30 depending on the embodiment.
6
[0026] An opening (14) of said bottle shaped enclosures (12) is kept at around 2 mm. Said opening (14) is kept small to avoid the flow of outside air from entering said dead volume of air space (13) within said bottle shaped enclosure (12).
5
[0027] To reduce the noise further, a thin layer of acoustic material (15) is applied on three sides of said muffler (10) to dampen the noise as it passes through said muffler (10). 4.5% in the absolute dB value on noise reduction is achieved.
[0028] Figure 2 and 3 shows two different possible embodiments of the muffler. 10 However, the embodiments should not be considered to be restricted to these only.
[0029] It should be noted that the description and figures merely illustrate the principles of the present subject matter. It should be appreciated by those skilled in the art that conception and specific embodiment disclosed may be readily 15 utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present subject matter. It should also be appreciated by those skilled in the art that by devising various assembly that, although not explicitly described or shown herein, embody the principles of the present subject matter and are included within its spirit and scope. Furthermore, all examples recited 20 herein are principally intended expressly to be for pedagogical purposes to aid the reader in understanding the principles of the present subject matter and the concepts contributed by the inventor(s) to furthering the art, and are to be construed as being without limitation to such specifically recited examples and conditions. The novel features which are believed to be characteristic of the 25 present subject matter, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures.
30
[0030] These and other advantages of the present subject matter would be described in greater detail with reference to the following figures. It should be
7
noted that the description merely illustrates the principles of the present subject matter. It will thus be appreciated that those skilled in the art will be able to devise various arrangements that, although not explicitly described herein, embody the principles of the present subject matter and are included within its scope.
5
[0031] It will be further appreciated that functions or structures of a plurality of components or steps may be combined into a single component or step, or the functions or structures of one-step or component may be split among plural steps or components. The present invention contemplates all of these combinations. Unless stated otherwise, dimensions and geometries of the various structures 10 depicted herein are not intended to be restrictive of the invention, and other dimensions or geometries are possible. In addition, while a feature of the present invention may have been described in the context of only one of the illustrated embodiments, such feature may be combined with one or more other features of other embodiments, for any given application. It will also be appreciated from the 15 above that the fabrication of the unique structures herein and the operation thereof also constitute methods in accordance with the present invention. The present invention also encompasses intermediate and end products resulting from the practice of the methods herein. The use of “comprising” or “including” also contemplates embodiments that “consist essentially of” or “consist of” the recited 20 feature.
[0032] Although embodiments for the present subject matter have been described in language specific to structural features, it is to be understood that the present subject matter is not necessarily limited to the specific features described. Rather, 25 the specific features and methods are disclosed as embodiments for the present subject matter. Numerous modifications and adaptations of the system/component of the present invention will be apparent to those skilled in the art, and thus it is intended by the appended claims to cover all such modifications and adaptations which fall within the scope of the present subject matter.

Claims:We claim:

1. An improved muffler (10) for mixer-grinder to reduce the operation noise, comprising:
sets of baffles (11) placed equidistant to each other to generate a bottle shaped enclosure (12);
dead volume of air space (13) created between said bottle shaped enclosure (12); and
a layer of an acoustic material (15) to produce said improved muffler (10) for mixer-grinder to reduce operational noise.

2. The improved muffler (10) as claimed in claim 1, wherein air flows on top of said bottle shaped enclosures (12) and said dead volume of air space (13) provides a resonating effect in tuning the frequency of the audible operational noise leading to reduction in the overall dB levels.

3. The improved muffler (10) as claimed in claim 1, wherein said baffles (11) cover 50 to 90% of the width of said muffler (10).

4. The improved muffler (10) as claimed in claim 1, wherein neck opening (14) of said bottle shaped enclosure (12) is small enough to avoid the airflow from entering said dead volume of air space (13) within said bottle shaped enclosure (12).

5. The improved muffler (10) as claimed in claim 1, wherein the length of said baffles (11) is equal.

6. The improved muffler (10) as claimed in claim 1, wherein said baffles (11) are curved.

7. The improved muffler (10) as claimed in claim 1, wherein the length of said baffles (11) is unequal.

8. The improved muffler (10) as claimed in claim 1, wherein said acoustic material (15) is polyurethane, foam.
, Description:AN IMPROVED MUFFLER FOR MIXER-GRINDER
FIELD OF INVENTION:
[001] The present invention in general relates to the field of home appliances. The present invention more particularly relates to a mixer-grinder with an improved muffler for reduction of noise.

BACKGROUND AND PRIOR ART:
[002] Home appliances such as mixer-grinders are too noisy for home environment. One significant source of noise is the motor that drives the entire unit. This noise is carried by the air that passes through the motor. The main function of this air is to cool the motor.

[003] Indian Patent No. 206887 discloses a mixer grinder which operates at reduced noise level. The airflow interrupter comprises a disc provided across the upper end of the silencer cum guide sleeve above the mounting bracket of the motor assembly, the disc being provided with spaced openings at the periphery thereof associated with arch like airflow obstructing baffles.

[004] Publication No. US6680551 discloses a motor housing assembly including an air exhaust cone for creating laminar air flow, and including an air exhaust passageway for reducing noise created by the operation of the motor.

[005] Publication No. US8579220 discloses a blender including a connection system that lowers the differences of coupling between the appliance base, where the motor is located, and the jar, where the crushing blades are located to be driven by the motor to blend the food. It has used damping material to reduce the audible noise generated due to the vibration of the apparatus. This is achieved by putting the damping system along the power transmission route. The coupling between the base assembly and jar assembly is reducing the vibrations.

[006] Publication No. EP2709750 is using isolation of the motor housing from any direct connection to the outer shell to reduce or eliminate the noise and vibration. However, it is not using silencer/muffler or any device that reduces the audible noise that is carried by the air flowing on the motor.

[007] Publication No. US5696358 discloses an appliance muffling device for reducing noise and vibrations produced by conventional appliances, such as blenders, comprising a uniform cover connectable to a uniform base enclosure both preferably having side walls where a connection is made through snapping engagement so as to form an interior volume for enclosing an appliance, wherein the switch or switches of the appliance are engageable by a slidable switch engaging member assembled on opposite sides of the base side walls through an aperture defined by the base side walls.

[008] Publication No. US5765257 discloses a vacuum cleaner muffler that could be used in other product applications, as may be desired. The muffler body includes a hollow cylindrical section or enlarged head with open opposite ends. A smaller hollow shaft extends within one open end of the hollow cylindrical section and is integrally connected to an inner circumferential wall of the hollow cylindrical section through a series of radially extending fins.

[009] Publication No. US2003042805 discloses a muffler incorporated into an electric motor housing to increase air flow across the motor and to reduce noise escaping from the housing.

[0010] Publication No. US5004068 discloses a muffler constructed to have a tubular perforated plate within its cavity to divide the cavity into an outer resonant cavity and an inner resonant cavity so as to have two resonant frequencies, the tubular perforated plate being formed in the shape of a funnel.

[0011] Publication No. WO2016196271 discloses an appliance including a reverse air flow motor housing. A casing carries and supports a motor, and a ventilation fan is rotated by a rotatable shaft driven by the motor. A lower platform with an air intake port carries a ventilation shroud that partially encloses the ventilation fan.

[0012] Thus, the present invention aims to provide a mixer-grinder with an improved muffler for reduction of noise.

OBJECTS OF THE INVENTION:
[0013] The principal objective of the present invention is to provide a mixer-grinder with an improved muffler for reduction of noise.

[0014] Another object of the present invention is to provide a mixer-grinder with an improved muffler along with the acoustic material on its inside surface to further reduce the noise.

SUMMARY OF THE INVENTION:
[0015] In accordance with the said objectives, the present invention provides a mixer-grinder with an improved muffler for reduction of noise. The muffler is provided along with an acoustic material on its inside surface, to reduce the noise in home appliances such as mixer-grinders. Muffler has a number of sets of baffles placed equidistant to each other to generate a bottle shaped enclosure. Baffles are curved and assembled in a way that air gets trapped in between them. This dead air is used to tune a particular frequency and change the tone of the noise as well.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered for limiting of its scope, for the invention may admit to other equally effective embodiments.
[0017] Figure 1 shows side view of the improved muffler according to the present invention.
[0018] Fig. 2 shows the top view of the improved muffler according to the present invention.
[0019] Figure 3 and 4 show two different possible embodiments of the muffler according to the present invention.
[0020] The figures depict embodiments of the present subject matter for the purposes of illustration only. A person skilled in the art will easily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.
DESCRIPTION OF THE PREFERRED EMBODIMENTS:
[0021] The present invention will be described in detail below with reference to an embodiment as shown in the drawing.
[0022] Accordingly the present invention provides a mixer-grinder with an improved muffler along with an acoustic material on its inside surface, to reduce the noise.
[0023] Referring to the figure 1, side view of the improved muffler (10) according to the present invention is given. Three sets of baffles (11) are placed equidistant to each other to generate a bottle shaped enclosure (12). Number of sets of said baffles (11) is not considered to be limited to three; it may differ based on the requirement. The gap between said bottle shaped enclosures (12) is a dead volume of air space (13).

[0024] The air in the muffler enters from an air flow inlet (20) and flows on top of said bottle shaped enclosures (12) (shown by the arrows in the figure) and exits from an air flow outlet (25). When outside air flows on top of said bottle shaped enclosures, said dead volume of air (13) provides a resonating effect which helps in tuning the frequency of the audible noise leading to reduction in the overall dB levels.

[0025] Said baffles (11) cover about 50 to 90% of the width of said muffler (10) depending on the embodiment.

[0026] An opening (14) of said bottle shaped enclosures (12) is kept at around 2 mm. Said opening (14) is kept small to avoid the flow of outside air from entering said dead volume of air space (13) within said bottle shaped enclosure (12).

[0027] To reduce the noise further, a thin layer of acoustic material (15) is applied on three sides of said muffler (10) to dampen the noise as it passes through said muffler (10). 4.5% in the absolute dB value on noise reduction is achieved.

[0028] Figure 2 and 3 shows two different possible embodiments of the muffler. However, the embodiments should not be considered to be restricted to these only.

[0029] It should be noted that the description and figures merely illustrate the principles of the present subject matter. It should be appreciated by those skilled in the art that conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present subject matter. It should also be appreciated by those skilled in the art that by devising various assembly that, although not explicitly described or shown herein, embody the principles of the present subject matter and are included within its spirit and scope. Furthermore, all examples recited herein are principally intended expressly to be for pedagogical purposes to aid the reader in understanding the principles of the present subject matter and the concepts contributed by the inventor(s) to furthering the art, and are to be construed as being without limitation to such specifically recited examples and conditions. The novel features which are believed to be characteristic of the present subject matter, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures.

[0030] These and other advantages of the present subject matter would be described in greater detail with reference to the following figures. It should be noted that the description merely illustrates the principles of the present subject matter. It will thus be appreciated that those skilled in the art will be able to devise various arrangements that, although not explicitly described herein, embody the principles of the present subject matter and are included within its scope.

[0031] It will be further appreciated that functions or structures of a plurality of components or steps may be combined into a single component or step, or the functions or structures of one-step or component may be split among plural steps or components. The present invention contemplates all of these combinations. Unless stated otherwise, dimensions and geometries of the various structures depicted herein are not intended to be restrictive of the invention, and other dimensions or geometries are possible. In addition, while a feature of the present invention may have been described in the context of only one of the illustrated embodiments, such feature may be combined with one or more other features of other embodiments, for any given application. It will also be appreciated from the above that the fabrication of the unique structures herein and the operation thereof also constitute methods in accordance with the present invention. The present invention also encompasses intermediate and end products resulting from the practice of the methods herein. The use of “comprising” or “including” also contemplates embodiments that “consist essentially of” or “consist of” the recited feature.

[0032] Although embodiments for the present subject matter have been described in language specific to structural features, it is to be understood that the present subject matter is not necessarily limited to the specific features described. Rather, the specific features and methods are disclosed as embodiments for the present subject matter. Numerous modifications and adaptations of the system/component of the present invention will be apparent to those skilled in the art, and thus it is intended by the appended claims to cover all such modifications and adaptations which fall within the scope of the present subject matter.