WO2024042252A1

WO2024042252A1 - A wet grinder

Info

Publication number: WO2024042252A1
Application number: PCT/EP2023/074317
Authority: WO
Inventors: Pramod AKULU; Satish Kumar Uppu
Original assignee: Versuni Holding B.V.
Priority date: 2022-08-26
Filing date: 2023-09-05
Publication date: 2024-02-29

Abstract

Present disclosure discloses a wet grinder (100), which includes a base unit (116), a drum (103) rotateably coupled to and extending from the base unit (116) and at least two rollers (101, 102) coupled to a holder (104) and in contact with the disc (114). Further, the wet grinder (100) includes at least one fin (105), connected to one side of each of the at least two rollers (101, 102) and configured to rotate along with rotation of corresponding roller of the at least two rollers (101, 102). This configuration of the wet grinder (100), in particular, the at least one fin (105) which rotates along the rotation of the corresponding roller agitates the ingredients to create turbulence, which helps in moving the ingredients that are stuck onto surfaces of the drum (103), towards a crushing zone. This facilitates in effective grinding of the ingredients, thereby reducing residue and grinding time.

Description

A WET GRINDER

TECHNICAL FIELD

Present disclosure generally relates to an electric appliance. Particularly, but not exclusively the present disclosure relates to a food processing unit. Further, embodiments of the present disclosure, discloses a wet grinder.

BACKGROUND

Food processing units are widely used for a variety of food processing activities such as grinding, blending, mixing and the like. Usually, these food processing units are motor driven, which are capable of processing food in a variety of forms as mentioned above. One such food processing unit, which is widely adapted to process food in substantially large quantities is a wet grinder. The wet grinder is an electric stone mill, which is used to grind ingredients to create fine and coarse batter. Generally, wet grinders include a discshaped stone fixed to an inner bottom surface of a rotatable metal cylindrical drum, and a plurality of rollers mounted on the drum stone, where the plurality of roller stones rotate relative to rotation of the metal cylindrical drum. Therefore, ingredients such as grains (such as rice) soaked in water, are introduced into the drum and the drum is rotated, so that the grains are ground between the rotating drum stone and the roller stones, to form batter.

Conventional wet grinders fail to grind all the ingredients introduced into the wet grinder, thereby yielding more amount of residue (particle size being more than 1mm - coarse batter) in the ground ingredients. Presence of residue in the ground ingredients can lead to increase in the grinding time or coarse batter, which is undesired. Considering this, different techniques has been adapted to reduce the residue in the ground ingredients. One such techniques include increasing relative rpm of the drum and the rollers to increase the processing speed. Due to higher rpms, there will be spillage of ingredients out of the wet grinder, which may be hazardous to the operator. Another such technique includes changing profile of the base stone and the rollers, which include conical rollers, tapered base stone, widened rollers. Such changing of profile call for increase in cost and are difficult in manufacturing, as it involves complex manufacturing techniques, which again is undesired.

The present disclosure is directed to overcome one or more limitations stated above or any other limitations associated with the known arts.

SUMMARY OF THE DISCLOSURE It is an objective to provide a wet grinder, which reduces residue in grounded ingredients, thereby improving grinding efficiency. The configuration of the wet grinder creates turbulence by agitating the ingredients, which facilitates in moving the ingredients stuck on surfaces of a drum towards a crushing zone and thus effectively grinding the ingredients in lesser grinding time.

To better address one or more of these concerns, in a first aspect of the disclosure there is provided a wet grinder. The wet grinder includes a base unit and a drum rotateably coupled to a coupler extending from the base unit. The drum is configured to accommodate a disc at a bottom surface of the drum. Further, the wet grinder includes a holder coupled to an adapter, which extends vertically from the bottom surface of the drum. Furthermore, the wet grinder includes at least two rollers coupled to the holder and in contact with the disc. The at least two rollers are configured to rotate relative to rotation of the drum. Additionally, the wet grinder includes at least one fin, connected to one side of each of the at least two rollers. The at least one fin is configured to rotate along with rotation of corresponding roller of the at least two rollers. This configuration of the wet grinder, in particular, the at least one fin which rotates along the rotation of the corresponding roller agitates the ingredients to create turbulence. The turbulence helps in moving the ingredients that are stuck or attached to surfaces of the drum towards a crushing zone (i.e., beneath the at least two rollers), thus facilitates in effective grinding of the ingredients, thereby reducing the residue and grinding time.

In an embodiment, the at least one fin includes a body, which is defined with a central cavity and structured to be connectable to one side of the at least two rollers and a plurality of flaps extending from the body. The configuration of the at least one fin (i.e., the flaps of the fins) aids in creating turbulence by agitating the ingredients. The turbulence helps in moving the ingredients that are stuck or attached to surfaces of the drum towards a crushing zone (i.e., beneath the at least two rollers), thus facilitates in effective grinding of the ingredients, thereby reducing the residue and increasing speed of the grinding.

In an embodiment, one side of each of the plurality of flaps defined with a tapered configuration. The tapered configuration aids in easy rotation of the at least one fin along the rotation of corresponding roller of the at least two rollers, without contacting inner surfaces of the drum.

In an embodiment, the plurality of flaps extending from the body are spaced apart at an angle ranging from 45 degrees to 90 degrees. Further, each of the plurality of flaps are defined with a curved tip. The curved tip provides safety to the operator during cleaning of the drum. In an embodiment, diameter of the at least one fin is smaller than the diameter of the at least two rollers. This aids in rotation of the at least one fin along the rotation of the at least two rollers without hampering rotation of the at least two rollers relative to rotation of the drum.

In an embodiment, the wet grinder includes a drive mechanism disposed in the base unit. The drive mechanism includes a motor and a gear arrangement which are configured to rotate the drum.

In another embodiment, a wet grinder is disclosed. The wet grinder includes a base unit and drum rotateably coupled to a coupler extending from the base unit. The drum is configured to accommodate disc at a bottom surface of the drum. Further, the wet grinder includes a holder coupled to an adapter, which extends vertically from the bottom surface of the drum. Furthermore, the wet grinder includes at least two rollers coupled to the holder. The at least two rollers are in contact with the disc and are configured to rotate relative to rotation of the drum. Additionally, the wet grinder includes a wiper rotateably coupled to the adapter and in between the at least two rollers. The wiper is configured to rotate along with rotation of the drum. The wiper aids in mobilizing stagnant batter at the center of the drum and thus increases the speed of grinding and reduces residue.

In an embodiment, the wiper includes a body defined with a central cavity and structured to rotatably couple to the adapter and a plurality of ribs extending from the body in a direction opposite to each other.

In an embodiment, the plurality of ribs extending from the body are spaced apart at an angle ranging from 90 degrees to 180 degrees.

It is to be understood that the aspects and embodiments of the disclosure described above may be used in any combination with each other. Several of the aspects and embodiments may be combined together to form a further embodiment of the disclosure.

The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.

BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS

The novel features and characteristic of the disclosure are set forth in the appended claims. The disclosure itself, however, as well as a mode of use, further objectives and advantages thereof, will best be understood by reference to the following detailed description of an embodiment when read in conjunction with the accompanying drawings. One or more embodiments are now described, by way of example only, with reference to the accompanying drawings wherein like reference numerals represent like elements and in which:

Figure. 1 illustrates a perspective view of a wet grinder, in accordance with an embodiment of the present disclosure.

Figure. 2 illustrates a sectional view of the wet grinder of Figure. 1.

Figure. 3 illustrates an exploded view of a portion of the wet grinder, in accordance with an embodiment of the present disclosure.

Figure. 4 illustrates a perspective view of a roller holding assembly of the wet grinder, in accordance with an embodiment of the present disclosure.

Figure. 5 illustrates a sectional view of Figure. 4.

Figure. 6 illustrates a perspective view of the roller holding assembly of the wet grinder, in accordance with another embodiment of the present disclosure.

Figure. 7 illustrates a sectional view of Figure. 6.

Figures. 8a and 8b illustrates a perspective views of a fin, in accordance with an embodiments of the present disclosure.

Figure. 9 illustrates a perspective view of a wiper, in accordance with an embodiment of the present disclosure.

Figures. 10a and 10b illustrate images obtained by CFD analysis during operation of the wet grinder known in the art and the wet grinder of the present disclosure, respectively, in accordance with an embodiment of the present disclosure.

Figures. Ila and 11b illustrate images obtained by CFD analysis during operation of the wet grinder known in the art and the wet grinder of the present disclosure, respectively, in accordance with another embodiment of the present disclosure.

The figures depict embodiments of the disclosure for purposes of illustration only. One skilled in the art will readily 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.

DETAILED DESCRIPTION

While the embodiments in the disclosure are subject to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the figures and will be described below. It should be understood, however, that it is not intended to limit the disclosure to the particular forms disclosed, but on the contrary, the disclosure is to cover all modifications, equivalents, and alternative falling within the scope of the disclosure.

It is to be noted that a person skilled in the art would be motivated from the present disclosure and modify various features of a wet grinder. Therefore, such modifications are considered to be part of the disclosure. Accordingly, the drawings show only those specific details that are pertinent to understand the embodiments of the present disclosure, so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skilled in the art having benefit of the description herein.

The terms “comprises”, “comprising”, or any other variations thereof used in the disclosure, are intended to cover a non-exclusive inclusion, such that a device that comprises a list of components does not include only those components but may include other components not expressly listed or inherent to such system, method, or assembly, or device. In other words, one or more elements in a system or device proceeded by “comprises. . . a” does not, without more constraints, preclude the existence of other elements or additional elements in the system or device.

In the following detailed description, embodiments of the disclosure are explained with reference to accompanying figures that form a part hereof, and in which are shown by way of illustration specific embodiments in which the disclosure may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the disclosure, and it is to be understood that other embodiments may be utilized and that changes may be made without departing from the scope of the present disclosure. The following description is, therefore, not to be taken in a limiting sense.

Figures. 1 and 2 illustrates a perspective view and sectional view of a wet grinder (100), respectively, which may be adapted to process hard and larger ingredients in substantially large quantities. As seen in Figures. 1 and 2, the wet grinder (100) may include a base unit (116), which may act as a platform for enclosing and supporting components of the wet grinder (100). Further, the wet grinder (100) may include a drive mechanism, which may be enclosed within the base unit (116). In an embodiment, the drive mechanism may include a motor (118) and gear arrangement (117) coupled to the motor (118). The gear arrangement (117) may be configured to cater to desired torque for operating the wet grinder (100) based on different processing requirements. Further, the wet grinder (100) may include a drum (103) [best seen in Figure. 3] which may be rotatably coupled to the base unit (116) through a shaft (115) extending from the base unit (116). The drive mechanism may be configured to rotate the drum (103) at predefined speeds based on the requirement. In an embodiment, the drum (103) may include an adapter (110), which may extend from a bottom surface of the drum (103). The adapter (110) may be a hollow component which may be rotateably supported by the shaft (115), such that, the adapter (110) may enclose the shaft (115). Further, the adapter (110) may include a coupler which may engage with a coupler (119) extending from the base unit (116), where the coupler (119) extending from the base unit (116) may be operated by the drive mechanism. Relative to rotation of the coupler (119), the adapter (110) may rotate, thereby resulting in rotation of the drum (103). Further, the drum (103) may be configured to rigidly accommodate a disc (114) on a bottom surface of the drum (103). The disc (114) may be configured to rotate along the rotation of the drum (103). As an example, the drum (103) may be made of stainless steel, transparent material and the disc (114) may be made of hard food grade material such as but not limiting to stainless steel, grinding stone and the like.

As apparent from Figures. 1-3, the wet grinder (100) may further include a holder (104) which may be coupled to the adapter (110), such that the holder (104) may enclose a portion of the adaptor. The holder (104) may be coupled to adapter (110) such that, the holder (104) remains stationary irrespective of rotation of the adapter (110). Further, the wet grinder (100) may include at least two rollers (101, 102) which may be rotatably coupled to the holder (104). The at least two rollers (101, 102) may be coupled to the holder (104) such that, the at least two rollers (101, 102) may be in contact with the disc (114) and may rotate relative to rotation of the drum (103) [thus, the disc (114)], due to traction between the at least two rollers (101, 102) and the disc (114). As seen in Figures. 1-7, the at least two rollers (101, 102) may be coupled at either sides of the holder (104) through pins (111) extending from either sides of the holder (104). The at least two rollers (101, 102) may be configured to rotate about an axis A- A of the pin (111) [as seen in Figures. 5 and 7], relative to rotation of the drum (103). In an embodiment, the each of the at least two rollers (101, 102) may be configured to rotate in opposite direction to each other, relative to rotation of the drum (103). That is, one roller of the at least two rollers (101, 102) may rotate in clock-wise direction, while the other roller of the at least two rollers (101, 102) may rotate in counter clock-wise direction, relative to rotation of the disc (114). Additionally, the wet grinder (100) may include a deflector (113) which may be coupled to the holder (104). The deflector (113) may be configured to divert the ingredients towards centre of the disc (114) for grinding. Referring further to Figures. 1-5, the wet grinder (100) may include at least one fin (105) which may be connected to one side of each of the at least two rollers (101, 102) and configuration of the at least one fin (105) will be elucidated in the below sections. The at least one fin (105) may be configured to rotate along with rotation of the at least two rollers (101, 102). As seen in Figures. 8a and 8b, at least one fin (105) may include a body (106) which may be defined with a central cavity and may be structured to be connectable to one side of the roller of the at least two rollers (101, 102) such that, the at least one fin (105) may rotate along the rotation of corresponding roller of the at least two rollers (101, 102). As an example, the at least one fin (105) may be connected to the side of the roller by mechanical joining such as but not limiting to fasteners (112). Further, the at least one fin (105) may include a plurality of flaps (107) extending away from the body (106). In an embodiment, one end of the plurality of flaps (107) may be defined with a tapered profile with a thickness higher at vicinity to the body (106) and the thickness decreases towards the edge of the flap (107). This configuration, mitigates contacting of the flap (107) with an inner surface of the drum (103) which may result in restricting movement of the ingredients towards a crushing/grinding zone. Further, peripheral diameter of the at least one fin (105) may be configured to be smaller than diameter of the at least two rollers (101, 102) such that, to facilitate rotation of the at least two rollers (101, 102) relative to rotation of the drum (103). As apparent from Figures. 6a-6b, the at least one fin (105) includes four flaps (107) which are spaced apart at right angles to each other. However, the same cannot be construed as a limitation since the at least one fin (105) may include less or more than four flaps (107) which may be spaced apart at any angle to each other, based on the requirement.

In an illustrated embodiment, the wet grinder (100) includes at least one fin (105) positioned on either sides of the at least two rollers (101, 102). That is, the at least one fin (105) is positioned on both an inner side and an outer side of each of the at least two rollers (101, 102). However, the same cannot be construed as a limitation since, the wet grinder (100), may include at least one fin (105) only on one side (i.e., outer side) of the at least two rollers (101, 102) or the wet grinder (100) may include at least one fin (105) on both sides (i.e., inner side and outer side) of the at least two rollers (101, 102). During operation (thus, rotation) of the at least one fin (105) along with the rotation of the at least two rollers (101, 102), the at least one fin (105) may agitate the ingredients to create turbulence. The turbulence created may help in moving the ingredients that are attached or stuck to inner surface of the drum (103), towards the grinding zone. This aids in improving effectiveness of the grinding thereby resulting in faster grinding and minimizing the residue. Referring to Figure. 9, in an embodiment, the plurality of flaps (107) may be defined with a curved tip with curvature of the tip in direction of rotation of the at least one fin (105). The curved tip ensures safety during operation of the wet grinder (100) and also during servicing of the wet grinder (100).

Turning back to Figure. 1 in relation to Figures. 6 and 7, the wet grinder (100) may include a wiper (108) which may be rotateably coupled to the adapter (110). The wiper (108) may be configured to rotate along the rotation of the adapter (110) [thus, the drum (103)]. As apparent from Figure. 9, the wiper (108) may include a body (106) defined with a central cavity and structured to rotatably couple to the adapter (110). In an embodiment, the wiper (108) may be disposed between the at least two rollers (101, 102), proximal to the disc (114) in the drum (103). Further, the wiper (108) may include a plurality of ribs (109) which extend from the body (106) in a direction opposite to each other. In an illustrated embodiment, the wiper (108) includes a pair of ribs (109) which are extending from the body (106) at 180 degrees apart. However, the same cannot be construed as limitation since the wiper (108) may include more than two ribs (109) which may be spaced apart at any angles based on the requirement. During rotation of the wiper (108), the wiper (108) may contact and mobilize stagnant ingredients at the centre of the drum (103) towards the crushing zone. This mobilization may increase the speed of grinding and reduces the residue.

In an operational embodiment, the drum (103) may rotate at a desired speed due to which the at least two rollers (101, 102) may rotate because of the traction between the at least two rollers (101, 102) and the disc (114). Along with rotation of the at least two rollers (101, 102), the at least one fin (105) connected to corresponding roller may rotate and the wiper (108) may rotate along the rotation of the drum (103). The at least one fin (105) may agitate the ingredients to create turbulence. The turbulence created may help is moving the ingredients that are attached or stuck to the inner surface of the drum (103), towards the grinding zone. Further, the wiper (108) which rotates along with rotation of the drum (103) may contact and mobilize stagnant ingredients at the centre of the drum (103) towards the crushing zone. This mobilization may increase the speed of grinding and also reduces the residue.

Example:

Further embodiments of the present disclosure will be now described with respective experiments carried out to determine ingredients flow, residue and grinding time. Ingredients flow pattern is determined using computational fluid dynamics (CFD). From CFD analysis stagnant zones is also determined. Figures. 10a and Ila depict CFD results of conventional wet grinder. As seen at zone ‘A’ in Figure. 10a, there exists a stagnant region and at zone ‘B’ in Figure. Ila the ingredients are pushed away from crushing zone [i.e., beneath the at least two rollers (101, 102)] and towards the inner surface of the drum (103). Whereas, as seen in Figures. 10b and 11b which depict CFD results of the wet grinder (100) of the present disclosure, at zone ‘C’ [as seen in Figure. 10b] the stagnant zones are reduced and flow of ingredient is improved with increased velocity and at zone ‘D’ [as seen in Figure. 11b] flow of ingredients is broken and as a result of turbulence, the ingredients are pushed towards the crushing zone. Thus, the configuration of the wet grinder (100) of the present disclosure results in lesser residue and grinding time.

Further, the residue of the ground ingredients in conventional and wet grinder (100) of the present disclosure is measured. The residue is measured by sieving the ground ingredients through 1mm size sieve and collected particles are measured for weight. Residue and grinding time of different types of conventional wet grinders and the wet grinder (100) of the claimed invention has been captured in the below table 1.

Table 1

As explained in the aforementioned result tables and as seen in Figures. 10b and 11b, the wet grinder (100) of the present disclosure yields lesser residue and lesser grinding time over the conventional wet grinders. It is evident that, inclusion of at least one fin (105) or wiper (108) in the wet grinder (100) has resulted in reducing both the residue and grinding time. Equivalents:

With respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations may be expressly set forth herein for sake of clarity.

It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases “at least one” and “one or more” to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles “a” or “an” limits any particular claim containing such introduced claim recitation to inventions containing only one such recitation, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an” (e.g., “a” and/or “an” should typically be interpreted to mean “at least one” or “one or more”); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of “two recitations,” without other modifiers, typically means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to “at least one of A, B, and C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, and C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances, where a convention analogous to “at least one of A, B, or C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, or C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase “A or B” will be understood to include the possibilities of “A” or “B” or “A and B.” While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting.

Referral Numerals:

Claims

1. A wet grinder (100), comprising: a base unit (116); a drum (103) rotateably coupled to a coupler (119) extending from the base unit (116), the drum (103) is configured to accommodate a disc (114) at a bottom surface of the drum (103); a holder (104) coupled to an adapter (110), extending vertically from the bottom surface of the drum (103); at least two rollers (101, 102) coupled to the holder (104) and in contact with the disc (114), the at least two rollers (101, 102) are configured to rotate relative to rotation of the drum (103); and at least one fin (105) connected to one side of each of the at least two rollers (101, 102), the at least one fin (105) is configured to rotate along with rotation of the corresponding roller of the at least two rollers (101, 102).

2. The wet grinder (100) as claimed in claim 1, where the at least one fin (105) comprises: a body (106) defined with a central cavity and structured to be connectable to one side of a roller of the at least two rollers (101, 102); and a plurality of flaps (107) extending away from the body (106).

3. The wet grinder (100) as claimed in claim 2, wherein one side of each of the plurality of flaps (107) is defined with a tapered configuration.

4. The wet grinder (100) as claimed in claim 2, wherein the plurality of flaps (107) extending from the body (106) are spaced apart at an angle ranging from 45 degrees to 90 degrees.

5. The wet grinder (100) as claimed in claim 2, wherein each of the plurality of flaps (107) are defined with a curved tip.

6. The wet grinder (100) as claimed in claim 1, wherein peripheral diameter of the at least one fin (105) is smaller than diameter of the at least two rollers (101, 102). The wet grinder (100) as claimed in claim 1, comprises a drive mechanism disposed in the base unit (116). The wet grinder (100) as claimed in any one of the preceding claims, wherein the drive mechanism comprises a motor (118) and a gear arrangement (117), configured to rotate the drum (103). A wet grinder (100), comprising: a base unit (116); a drum (103) rotateably coupled to a coupler (119) extending from the base unit (116), the drum (103) is configured to accommodate a disc (114) at a bottom surface of the drum (103); a holder (104) coupled to an adapter (110), extending vertically from the bottom surface of the drum (103); at least two rollers (101, 102) coupled to the holder (104) and in contact with the disc (114), the at least two rollers (101, 102) are configured to rotate relative to rotation of the drum (103); and a wiper (108) rotateably coupled to the adapter (110) in between the at least two rollers (101, 102), the wiper (108) is configured to rotate along rotation of the drum (103). The wet grinder (100) as claimed in claim 9, wherein the wiper (108) comprises: a body (106) defined with a central cavity and structured to rotatably couple to the adapter (110); and a plurality of ribs (109) extending from the body (106), in a direction opposite to each other. The wet grinder (100) as claimed in claim 9, wherein the plurality of ribs (109) extending from the body (106) are spaced apart at an angle ranging from 90 degrees to 180 degrees. The wet grinder (100) as claimed in claim 9, comprises a drive mechanism disposed in the base unit (116), the drive mechanism comprises a motor (118) and a gear arrangement (117), configured to rotate the drum (103) and the wiper (108).