Scraper assembly for food processor

Abstract

A scraper assembly (1) for a mixing unit (2) having a vessel (4) with internal walls (8), the scraper assembly (1) comprising an elongated supporting rod (3) configured to be mounted inside the vessel (4) and a scraper body (5) having a first edge (6) and a second edge (7) opposite to the first edge (6), the scraper body (5) being pivotally mountable in a removable way to the supporting rod (3) at the first edge (6) and being configured to scrape the internal walls (8) of the vessel (4) at the second edge (7), wherein the scraper assembly further comprises a spring member (9) fixable to the supporting rod (3) and coupled to the scraper body (5) to make the scraper body (5) spring-loaded.

Description

[0001] SCRAPER ASSEMBLY FOR FOOD PROCESSOR

[0002] Technical Field

[0003] The invention relates to a scraper assembly for a mixing unit, such as a food processor, used for scraping the internal walls of the mixing unit. Also, the invention relates to a mixing unit comprising the scraper assembly and to a scraper body being a part of the scraper assembly. Furthermore, the invention relates to a method for arranging the scraper body and the scraper assembly into the vessel of the mixing unit.

[0004] The mixing of food products in a tank of a food processor is a standard practice in many processes in the food industry. The mixing process is usually carried out by a plurality of blades, also known as agitator blades, which are coupled to a central rotating shaft that extends longitudinally along the tank of the food processor. In this way, the blades mix the food product present inside the tank. Based on the type of product to be mixed and based on the process to which the product undergoes, the food processor and the corresponding components can be configured in different ways.

[0005] In some cases, the mixing process is combined with a scraping process to scrape the internal walls of the tank from food products remained attached to these walls. For this purpose, dedicated scraping blades usually extend essentially parallel to the axis of the central rotating shaft to which they are coupled. The blades continuously scrape the food product from the inner walls of the tank and prevent the product from sticking to or burning at the internal walls of the tank.

[0006] The scraper elements are typically made of plastic materials like PTFE, PVDF or PEEK, to reduce friction and wear on the tank’s walls. Therefore, scrapers are replaced frequently due to wear and the resulting reduced scraper performance. The replacement of scrapers often needs the access into the tank. This implies working in a confined space, which is a safety issue. In addition, for some tanks, a safe access is not possible due to the presence of agitator blades that can prevent safe evacuation. In these situations, the tank can be configured so that one of the tank ends is connected via a bolt on flange. However, for large tanks such types of flanges are extremely costly. In other words, in standard scraping systems, scraper elements are cleaned and / or replaced by entering into the tank. In alternative, the complete scraper shaft assembly can be removed from the tank via large bolt flanges. Accordingly, known solutions can provide complex arrangements of components that could lead to difficult and unsafe cleaning procedures and increased efforts in replacing the worn parts. Furthermore, it is noted that the performance of standard scraper blades can be different if these are applied into vertical or horizontal tanks. In fact, the effect of the gravity action on the food product inside the tank makes the scraping process less effective for the tanks laying horizontally.

[0007] It is an object of the invention to at least partly overcome one or more of the above-identified limitations of the prior art. In particular, it is an object to provide a scraper assembly and a scraper body as part of the assembly that is easily cleanable and replaceable. Also, it is an object to provide a scraper assembly and a scraper body as part of the assembly that is efficient regardless of the tank orientation.

[0008] To solve these objects a scraper assembly for a mixing unit having a vessel with internal walls as well as a scraper body being a part of the scraper assembly are provided. The scraper assembly comprises an elongated supporting rod configured to be mounted inside the vessel, and a scraper body having a first edge and a second edge opposite to the first edge, the scraper body being pivotally mountable in a removable way to the supporting rod at the first edge and being configured to scrape the internal walls of the vessel at the second edge, wherein the scraper assembly further comprises a spring member fixable to the supporting rod and coupled to the scraper body to make the scraper body spring-loaded.

[0009] The scraper assembly so configured is advantageous in that the scraper body can be easily removed from the vessel. Since the scraper body is the assembly’s component that is most likely subjected to wear, the possibility of removing it from the supporting rod is extremely useful to reduce maintenance times and costs. Also, the coupling between the scraper body and the spring member allows for an efficient scraping action. In fact, since the scraper body is spring loaded, one edge of the scraper body is continuously pushed against the internal walls of the vessel, thereby producing a continuous contact surface between the body and the walls during the scraping process.

[0010] It is noted that the scraper assembly can have a single scraper body or a plurality of scraper bodies mounted to the same supporting rod. The plurality of scraper bodies can preferably be arranged equidistantly from each other. However, based on the particular requirements of scraping actions in the vessel, the distance between two consecutive scraper bodies can be different (i.e. not constant). Since each scraper body is coupled to a spring member, in case of a plurality of scraper bodies, the scraper assembly comprises also a plurality of spring members, wherein each spring member is coupled to a corresponding scraper body.

[0011] In one example, the scraper body can comprise an attachment portion at the first edge for the mounting of the scraper body to the supporting rod. The attachment portion serves to couple the scraper body to the rod in a way that the scraper body can pivot on the supporting rod. The scraper body can comprise a single attachment portion located for example in a central region of the first edge or can comprise a plurality of these portions. For example, the scraper body can have two separated attachment portions. The attachment portion can have any shape suitable for making the scraper body pivotable mountable to the supporting rod.

[0012] According to one example, the attachment portion might comprise a through- hole for receiving the supporting rod. In other words, the attachment portion can have a closed ring shape for allowing the supporting rod to pass through. The scraper body can have a single central long through hole structure or a plurality (e.g. two) separated short through hole structures that are coaxial distributed along the first edge of the scraper body. In alternative or in addition, the attachment portion can have a clamp mechanism, a threaded connection, a quick-release coupling, a snap-fit attachment, a clip mechanism, a bayonet mount, or the like.

[0013] In order to make the scraper body spring-loaded, the spring member can be in contact with the scraper body to exert a biasing force on the scraper body so that the second edge of the scraper body is kept in contact with the internal walls of the vessel when the supporting rod is mounted inside the vessel of the mixing unit. In other words, once the scraper assembly is mounted inside the vessel, the biasing action of the spring member on one surface of the scraper body constantly pushes the scraper body, specifically the second edge of the scraper body, on the internal walls of the vessel. In this way, the scraping performance of the scraper assembly are improved due to a constant contact surface between the scraper body and the vessel.

[0014] The spring member can be a single-piece wire element comprising a biasing bar to be in contact with the scraper body and two connecting pins for fixing the spring member to the supporting rod. Specifically, the spring member can be shaped in a way to be firmly fixed to the rod and at the same time having flexibility in the movement around the central axis of the rod.

[0015] The supporting rod can comprise at least two holes for the fixing of the spring member to the supporting rod. Specifically, the two holes serve to receive the connecting pins of the spring member. The holes are arranged on a same line along the longitudinal direction of the supporting rod. The distance between the rods correspond to the distance between the connecting pins of the spring member. In this way, when the pins are inserted into the holes, the spring member is fixed to the rod in a way that the spring cannot be moved along the longitudinal direction of the rod.

[0016] In one example, the supporting rod comprises at least a recessed portion for being coupled to an internal component of the mixing unit. Specifically, the rod can have a circular cross section and the recessed portion can be a linear cut out from the circular shape of the rod. The recessed portion can be located close to one end of the rod and serves to lock the rod with an internal component of the mixing unit, for example an agitator blade. Specifically, to improve the locking mechanism, the recessed portion might comprise a first recess and a second recess opposite to the first recess to be engaged with a C-shaped element.

[0017] The supporting rod might furthermore comprise a tapered tip for being inserted into an internal component of the mixing unit. Advantageously, the tapered tip is located to the opposite end of the rod where the recessed portion is present so that the rod can be fixed to the mixing unit by first inserting the tapered tip into an internal component of the mixing unit and then by coupling the recessed portion to another internal component of the mixing unit. This procedure can be easily carried out at the manway of the mixing unit without the necessity of entering into the vessel.

[0018] Also, to solve the above mentioned objects, a mixing unit is provided. The mixing unit comprises a vessel having inner walls for containing a product to be mixed, a rotating shaft extending longitudinally inside the vessel, a plurality of agitator blades coupled to the shaft and used for mixing the product inside the vessel, and at least a scraper assembly, the scraper assembly being mounted in a removable way inside the vessel by locking the elongated supporting rod of the scraper assembly to the agitator blades.

[0019] In this way, the entire scraper assembly can be easily inserted into, and removed from, the vessel without the necessity of entering into the vessel or disassembly parts of the vessel, e.g. a flange at the ends of the vessel. In fact, the present scraper assembly is configured to be removed by simply unlocking the elongated rod from the agitator blades and removing from the vessel. It is noted that both actions of unlocking and removing the scraper assembly can be carried out through the manway without big efforts and without completely entering into the vessel. This is especially useful when other components, such as agitator blades, are present into the vessel. In addition, to solve the above mentioned objects, a method of arranging a scraper body in a mixing unit is provided. The method comprises mounting the scraper body to an elongated supporting rod, fixing a spring member to the supporting rod, coupling the spring member to the scraper body to make the scraper body spring- loaded, forming a scraper assembly comprising at least the scraper body, the supporting rod and the spring member, and mounting the scraper assembly into the mixing unit.

[0020] Accordingly, the scraper body can be cleaned and singularly removed from the assembly with reduced efforts.

[0021] In one example, fixing the spring member to the supporting rod can comprise inserting two connecting pins of the spring member into two corresponding holes of the supporting rod and coupling the spring member to the scraper body can comprise rotating the spring member around a central axis of the supporting rod to interlock the spring member with the scraper body so that any linear movement of the scraper body and of the spring element in the direction of the central axis of the supporting rod is prevented.

[0022] In this way, the scraper assembly is more compact and stable since the locking and the unlocking of the spring member with respect to the scraper body can only be possible through a relative rotational movement between these two components Any linear movement is prevented.

[0023] The mounting of the scraper assembly into the mixing unit can comprise locking the supporting rod to at least an agitator blade of the mixing unit. In this way, the scraper assembly is coupled to the central rotational shaft of the mixing unit by means of the agitator blades and is stable connected to these component. Advantageously, the supporting rod is locked to the extremities of the agitator blades, i.e. close to the walls of the vessel, so that can be easily accessible for the outside, for example from the manway.

[0024] According to an example, locking the supporting rod to the agitator blade of the mixing unit comprises inserting a recessed portion of the supporting rod into an extremity of the agitator blade and rotating the supporting rod around its central axis to engage the extremity of the agitator blade with the recessed portion of the supporting rod so that any movement of the supporting rod relative to the agitator blade is prevented when the scraper body of the scraper assembly is in contact with internal walls of the mixing unit. This particular type of configuration further improve the locking mechanism of the scraper assembly with the agitator blade. Embodiments of the invention will now be described, by way of example, with reference to the accompanying schematic drawings, in which

[0025] Fig. 1A is a representation of a disassembled scraper assembly.

[0026] Fig. 1 B is a perspective representation of an assembled scraper assembly.

[0027] Fig. 2A is a perspective view of the scraper body.

[0028] Fig. 2B is a perspective view of the spring member.

[0029] Fig. 3A is an initial step of the coupling between a scraper body and a spring member.

[0030] Fig. 3B is a further step of the coupling between a scraper body and a spring member.

[0031] Fig. 3C is another step of the coupling between a scraper body and a spring member.

[0032] Fig. 3D is a final step of the coupling between a scraper body and a spring member.

[0033] Fig. 3E is a later view of the scraper body coupled to the spring member after the step of figure 3D.

[0034] Fig. 4 is a representation of the scraper assembly that is going to be inserted into a mixing unit.

[0035] Fig. 5A a perspective representation of the insertion of scraper assembly into the mixing unit

[0036] Fig. 5B is a representation of the coupling between the scraper assembly and the agitator blades of the mixing unit and a corresponding detail.

[0037] Fig. 6 is a representation of the coupling and locking between the scraper assembly and agitator blades of the mixing unit and corresponding details.

[0038] Fig. 7A is an initial step of the locking between a scraper assembly and the agitator blade.

[0039] Fig. 7B is a further step of the locking between a scraper assembly and the agitator blade.

[0040] Fig. 70 is a final step of the locking between a scraper assembly and the agitator blade.

[0041] Fig. 8A is a front view of the scraper assembly in the step of figure 7A.

[0042] Fig. 8B is a cross section along the line G-G of figure 8A.

[0043] Fig. 80 is a front view of the scraper assembly in the step of figure 7B.

[0044] Fig. 8D is a cross section along the line F-F of figure 80.

[0045] Fig. 8E is a front view of the scraper assembly in the step of figure 70. Fig. 8F is a cross section along the line E-E of figure 8E.

[0046] Fig. 9A is a detail of the extremity of an agitator blade.

[0047] Fig. 9B is one step of the locking mechanism between the extremity of the agitator blade of figure 9A and the supporting rod.

[0048] Fig. 9C is another step of the locking mechanism between the extremity of the agitator blade of figure 9A and the supporting rod.

[0049] Fig. 10 is a flow chart of the method of arranging the scraper body of the scraper assembly in a mixing unit.

[0050] With reference to Fig. 1A, a scraper assembly 1 is illustrated. The scraper assembly 1 is used for cleaning the walls inside a tank and is composed by an elongated rod 3, a scraper body 5 and a spring member 9. The elongated rod 3 is preferably a cylindrical shaft provided with a plurality of holes 15 linearly arranged along the direction of the central axis 28 of the rod 3. The scraper body 5 has a first edge 6 and a second edge 7 and is mountable to the supporting rod 3 at the first edge 6 in a way that the body 5 can pivot about the central axis 28 of the rod. For this purpose, two attachment portions 11 having each a through-hole 12 are present at the first edge 6. Accordingly, the scraper body 5 is coupled to the rod 3 by inserting the elongated rod 3 in the through-holes 12. The though-holes 12 have a circular, or almost circular, cross-section so that the scraper body 5 is pivotably movable around the rod 3. The second edge 7 of the scraper body 5 is opposite to the attachment portions 11 , i.e. to the first edge 6, and is configured to scrape the internal walls of the tank, as shown in the following figures.

[0051] The spring member 9 is used to fix the scraper body 5 to the rod 3 and is coupled to the scraper body 5 in a way to make it spring-loaded. The spring member 9 comprises two connecting pins 14 that are used to be inserted into the holes 15 of the elongated rod 3. For this purpose, the distance between the two holes 15 corresponds to the distance between the two pins 14. Once the pins 14 of the spring member 9 are inserted into the holes 15, the spring member 9 is coupled to the scraper body 5 in a way that a biasing bar 13 of the spring member 9 constantly acts on a front surface 10 of the scraper body 5, thereby generating a tension on said front surface 10. It is noted that the spring member 9 determines a locking mechanism between the scraper body 5 and the elongated rod 3. However, scraper body 5 is not permanently fixed to the rod 3, rather the scraper body 5 can be easily slid away from the rod 3 once the spring member 9 is disassembled from the elongated rod 3, i.e. once the pins 14 are extracted from the holes 15. This is extremely useful in case the scraper body 5 needs to be replaced or cleaned.

[0052] Figure 1B illustrates a possible configuration of the scraper assembly 1. This figure shows a single elongated rod 3 with four scraper bodies 5 and four corresponding spring members 9. Specifically, the scraper assembly 1 is made of a single rod 3 and a plurality of subassemblies consisting of a scraper body 5 and a spring member 9. Each spring member 9 is fixed to the rod 3 by inserting the pins 14 into the corresponding holes 15 of the rod 3 and is configured to bias against the scraper body 5. In this case, the supporting rod 3 is provided with four pairs of holes 15 to receive the corresponding pins 14 of the four spring members 9. The subassemblies (scraper body 5 / spring member 9) are equidistantly distributed along the longitudinal direction of the elongated rod 3 to ensure a uniform scraping action of the entire assembly 1. However, both the number of subassemblies and their reciprocal distance can be different based on the circumstances, i.e. based on the dimension of the tank, the type of the food product to be scraped, the surface area of the internal walls to be cleaned, etc. For example, the scraper assembly 1 can comprise a single subassembly made of a single scraper body 5 coupled to a single spring member 9, the scraper body 5 extending along the entire, or a partial, length of the rod 5.

[0053] It is noted that the elongated rod 3 is provided with a tapered tip 21 at one end and recessed portions 16 close to the opposite end. Both the tapered tip 21 and the recessed portions 16 are used to fix and lock the scraper assembly 1 into the vessel 4 of a mixing unit 2, as will be described in detail in the following figures.

[0054] The detailed structures of the scraper body 5 and of the spring member 9 are illustrated in figures 2A and 2B. With reference to figure 2A, a scraper body 5 is shown. The scraper body 5 has a plate structure and is used like a spatula for scraping residual food products from the internal walls 8 of the vessel 4 of a mixing unit 2. Also, the second edge 7 can have curved corners to facilitate the scraper action.

[0055] The length of the scraper body 5 (i.e. along the direction of first and second edges 6, 7) can be greater than the width (i.e. along the direction orthogonal to the first and second edges 6, 7). For example, the length of the scraper body 5 can be at least two times the width. As already mentioned, the ratio of these dimensions can change based on the number of scraper bodies 5 mounted to the rod 3 and also on the vessel’s characteristics. The body 5 has a tapered shape in the direction from the first edge 6 to the second edge 7 meaning that the thickness of the first edge 6 is greater than the thickness of the second edge 7 that is used for the scraping function. In particular, the scraper body has a front surface 10 and a rear surface 43 both extending from the first edge 6 to the second edge 7, the front surface 10 forming an angle a with the rear surface 43. For example, the angle a can be comprised between 15 degrees and 30 degrees.

[0056] The tapered structure can be advantageous for the flexibility of the scraper body 5 during the scraping. In fact, the spring member 9 acts on the front surface 10 for maintaining the scraper body 5 in contact with the internal walls 8 of the vessel 4 and the inclination of the first surface 10 relative to the rear surface 43 allows a smooth shift of the biasing bar 13 on the front surface 10 as a consequence of a possible rotational movement of the scraper body 5 relative to the rod 3 during the scraping process.

[0057] At the first edge 6, the scraper body 5 comprises two attachment portions 11 used for attaching the scraper body 5 to the rod 3. For this purpose, each attachment portion 11 comprises a through-hole 12 for receiving the elongated rod 3. The through holes 12 are coaxial and, for stability reasons, the attachment portions 11 are equidistant from the central region of the first edge 6. The two attachment portions 11 are arranged at a distance L1 from each other.

[0058] The attachment portions 11 have an “open structure” meaning that these portions 11 are configured to be easily cleanable. In particular, each attachment portion 11 comprises a wide base portion 41 and an opposite thin top portion 42, wherein the top portion 42 includes a first cut-out 39 and a second cut-out 40. The first and second cut-outs 39, 40 are arranged at opposite sides of the top portion 42. In particular, the first and second cut-outs 39, 40 extend only partially on one side of the attachment portion 11. Specifically, the first cut-out 39 extends on a first half of the attachment portion 11 and the second cut-out 40 extends on a second half of the attachment portion 11. The two cut-outs 39, 40 are arranged symmetrically in the diagonal direction so that the first cut-out 39 at one side of the attachment portion 11 corresponds to a region on the opposite side of the attachment portion 11 (first half) where no cut-out is present. Similarly, the second cut-out 40 at the other side of the attachment portion 11 corresponds to a region on the opposite side of the attachment portion 11 (second half) where no cut-out is present. This particular configuration ensures a better stability for the rotational movement of the scraper body 5 relative to the rod 5, thereby maintain an open structure configuration.

[0059] It is noted that for the purpose of scraping function, the attachment portions 11 can also be manufactured without cut-outs. However, the absence of cut-outs would make the scraper body 5 more compact, thereby negatively affecting the cleaning procedures. With reference to figure 2B, the structure of the spring member 9 is shown. The spring member 9 can be a single-piece wire element that is shaped to give specific elastic properties to the spring member 9. The spring member 9 has a symmetrical shape with respect to central longitudinal plane 45 as schematically shown in the figure on the left side. Due to this symmetric shape, only one side (i.e. the right side) of the spring member 9 is described in detail, the other side (i.e. the right side) being formed in the same way. The spring member 9 has a pin 14 used for being inserted into the hole 15 of the elongated rod. The pin 14 has an elongated straight shape and is connected to a curved portion 35 that coils around the pin 14. The curved portion 35 is then connected to a first straight portion 36 extending almost parallel to the pin 14. Through a first bent portion 37, the first straight portion 36 is connected to a second straight portion 38, the second straight portion 38 being shorter than the first straight portion 36. The second straight portion 38 is connected to the biasing bar 13 through a second bent portion 44. The biasing bar 13 extend longitudinally in a direction almost orthogonal to the longitudinal direction of the pin 14.

[0060] The two pins 14 of the spring member 9 are arranged at a distance L2 from each other, this distance corresponding to the distance between the two holes 15 present on the elongated rod 3. In one example, the distance between two attachment portions 11 of the scraper body 5 is greater than the distance between the two pins 14 of the spring member 9, i.e. L1>L2. In this way, the curved portions 35 of the spring member 9 can be accommodated inside the space between the two attachment portions 11 of the scraper body 5. However, in an alternative example, the scraper assembly 1 can be configured in a way that L1<L2 so that the curved portions 35 of the spring member 9 can be accommodated outside the space between the two attachment portions 11 of the scraper body 5.

[0061] Figures 3A-3E illustrate the coupling procedure among the different components of the scraper assembly 1. In particular, these figures show the fixing of the spring member 9 to the rod 9 and the corresponding coupling between the spring member 9 and the scraper body 5. In a first step (figure 3A), the spring member 9 is placed in a space between the attachment portions 11 of the scraper body 5. Specifically, the coils of the curved portions 35 of the spring member 9 are placed at the through holes 12 of the attachment portions 11 of the scraper body 5. This procedure is carried out with the scraper body 5, i.e. the front and rear surfaces 10, 43 of the scraper body 5, being oriented almost orthogonally with respect to the direction of the pins 14. In a second step (figure 3B), when the spring member 9 is in place, the elongated rod 3 is inserted into the attachment portions 11 of the scraper body 5. By passing through the attachment portions 11, the rod 3 also passes through the curved portions 35 of the spring member 9, and specifically through a space between the ends of the pins 14 and the coils of the curved portions 35. The elongated rod 3 is moved through the attachment portions 11 until each hole 15 is placed at an end of a corresponding pin 14. The spring member 9 can then be moved upwards so that each pin 14 can be inserted into the corresponding hole 15 of the rod 3 (figure 3C). Once the pins 14 are completely inside the holes 15, the scraper body 5 can be rotated around the central axis 28 of the rod 3, for example clockwise in figure 3D. Consequently, the scraper body 5, i.e. the front and rear surfaces 10, 43 of the scraper body 5, are oriented almost parallel to the direction of the pins 14 and the biasing bar 13 enters into contact with the front surface 10 of the scraper body 5. In this way, a tension is provided by the spring member 9 to the front surface of the scraper body 5 so that, when the scraper assembly 1 is mounted inside the vessel 4 of the mixing unit 2, the scraper body 5 is kept in contact with the internal walls 8 of the vessel 4.

[0062] Figure 3E shows a lateral view of the assembly of figure 3D. From the figure it is clear how the spring member 9 wraps around the elongated rod 3 and touches the scraper body 5 only at the biasing bar 13 so that all the tension of the spring member 9 is concentrated at this region of the front surface 10 that is almost at the second edge 7 of the scraper body 5. In this way, the scraper action is improved compared to standard scraper systems.

[0063] It is noted that figures 3A-3E illustrate the interlocking mechanism between the scraper body 5 and the spring member 9. As a matter of fact, once these two components are in the configuration of figure 3D, both the scraper body 5 and the spring member 9 cannot move in the direction of the central axis 28 of the rod 3. The scraper body 5 cannot move in this direction due to the presence of the curved portions 35 of the spring element 9 that are fixed to the rod 3 and are located between the attachment portions 11. At the same time, the spring member 9 cannot move as well since the clockwise rotation of the scraper body 5 abutting with the front surface 10 against the biasing bar 13 of the spring member 9 prevents the pins 14 of the spring 9 to be extracted from the holes 15. The only way to unlock the scraper body 5 from the spring member 9 is to rotate the scraper body 5 in the anti-clock direction so that it is arranged as in figure 3C. In this configuration, there is no tension on the spring 9 and the pins 14 can be extracted from the holes 15 so that the rod can be slid away from the attachment portions 11. In other words, the rotation of the scraper body 5 about the elongated rod 3 determines the locking and unlocking mechanism between the scraper body 5 and the spring member 9. In the locked position (figure 3D) any linear movement along the rod 3 of these components is therefore prevented.

[0064] Figure 4 illustrates the insertion of the scraper assembly into the vessel 4 of the mixing unit 2. The mixing unit 2 is an horizontal type mixing unit 2 having a vessel 4 placed horizontally relative to the ground. In particular, the vessel 4 has a cylindrical shape with a longitudinal axis oriented almost parallel to the ground. As shown in the figure, the scraper assembly 1 can easily be inserted into the vessel 4 through the manway 27 located on the top of the vessel 4. Therefore, it is not necessary to disassemble parts of the vessel 4, i.e. a lateral flange, thereby reducing the complexity and the time of the mounting / unmounting procedures. In addition, it is not necessary to completely enter inside the vessel 4. In fact, the mounting and unmounting procedures are possible remaining outside the vessel 4 by handling the scraper assembly 1 directly from the manway 27. This improves the safety for the personnel.

[0065] The mounting procedure is better clarified in figures 5A and 5B. These figures illustrate the mixing unit 2 of figure 4 without the lateral covering of the vessel 4 to show the interior of the vessel 4. The mixing unit 2 is provided with a central rotating shaft 19 extending along the vessel 4 in the longitudinal direction. The rotating shaft 19 is coupled to a plurality of agitator blades 20, 21, 22 that rotate together with the shaft 19 for mixing and blending the food product. The agitator blades 20, 21, 22, grouped in pairs, have an elongated structure and are connected to the rotating shaft 19 at their central portion. As shown in the figure, there are three pairs of agitator blades 20, 21, 22. A first pair of blades 20 located close to the manway 27, a second pair of blades 21 located in the center of the vessel 4 and a third pair of blades 22 located far away from the manway 27. As will be described in detail with reference to figure 6, the extremities

[0066] 24, 25, 26 of the agitator blades pairs 20, 21, 22 can have different shapes based on different purposes of application.

[0067] The scraper assembly 1 can be inserted through the manway 27 and mounted to the extremities 24, 25, 26 of the agitator blades 20, 21 , 22. Since the extremities 24,

[0068] 25, 26 of the agitator blades 20, 21 , 22 are located close to the internal walls 8 of the vessel 4, the mounting procedure can be carried out close to these walls 8, thereby reducing the mounting efforts for the dedicated personnel. Specifically, the scraper assembly 1 is mounted into the vessel 4 by first introducing one end, i.e. the end comprising the tapered tip 23 and coupling said end with the extremity 26 of the farthest blade agitator 22 from the manway 27. The farthest blade agitator 22 from the manway 27 has a through-hole extremity 26 and is configured to receive the tapered tip 23 of the scraper assembly 1 (see detail A of figure 5B). It is noted that once the tapered tip 23 of the scraper assembly 1 is inserted into the through-hole extremity 26 of the agitator blade 22, the scraper assembly 1 is completely inserted into the vessel 4.

[0069] As already mentioned, there are three pairs of agitator blades 20, 21, 22, wherein each pair has its own type of extremity. The agitator blades 20, 21 , 22 of each pair are arranged opposing each other so that three agitator blades 20, 21 , 22 have the extremities arranged along a first (same) line and other three agitator blades 20, 21 , 22 have the extremities arranged along a second (same) line opposite to the first line. According to this configuration, one scraper assembly 1 can be locked to the extremities 24, 25, 26 of the agitator blades 20,21 , 22 along the first line and another scraper assembly 1 can be locked to the extremities 24, 25, 26 of the agitator blades 20,21, 22 along the second line. Figure 5B only shows the presence of a single scraper assembly 1 that is locked to the extremities 24, 25, 26 of the agitator blades 20, 21, 22 located on the upper internal region of the vessel 4. A second scraper assembly 1 can be also locked to the extremities 24, 25, 26 of the agitator blades 20, 21, 22 located on the lower internal region of the vessel 4.

[0070] Figure 6 illustrates in details the three agitator blades 20, 21, 22 and the corresponding specific type of extremities 24, 25, 26 used for fixing and locking the scraper assembly 1, i.e. the elongated rod 3 of the scraper assembly 1.

[0071] Specifically, the mixing unit 2 comprises three types of agitator blades, i.e. a first type of agitator blade 20 (locking blade), a second type of agitator blade 21 (supporting blade) and a third type of agitator blade 22 (inserting blade). The agitator blade of the first type 20 comprises a C-shaped extremity 24 (see detail D), the agitator blade of the second type 21 comprises a U-shaped extremity 25 (see detail C), and the agitator blade of the third type 22 comprises a through-hole extremity 26 (see detail B). The agitator blades of the first and third types 20, 22 are located close to the ends of the vessel 4, whereas the agitator blade of the second type 21 is located between the blades of the first and third type 20, 22. As a matter of fact, the agitator blade of the third type 22 serves for inserting the tapered tip 23 of the elongated rod 3 of the scraper assembly. For this purpose, this blade comprises a through-hole extremity 26. To ease the mounting procedure, this blade can be located far away from the manway 27 of the vessel 4. The agitator blade of the first type 20 serves, on the other hand, to lock the blade 20 to the rod 3. For this purpose, this blade comprises an extremity with a dedicated shape, i.e. a C-shaped extremity 24, configured to engage the rod 3 at a recessed portion 16 that includes a first recess 17 and a second recess 18. This particular engagement will be described in more detail with reference to the following figures. To ease the mounting procedure, this locking blade 20 can be located at the manway 27 of the vessel 4. The agitator blade of the second type 21 serves to support the rod 3. For this purpose, this blade comprises an extremity with a dedicated shape, i.e. a U-shaped extremity 25. Differently from the C-shaped extremity 24 having an outline with protrusions and recesses, the U-shaped extremity 25 has a semi-circle outline without protrusions or recesses.

[0072] According to the figure, the scraper assembly 1 is mountable to, and lockable with, three agitator blades 20, 21 , 22 in total. However, the scraper assembly 1 can be attached to more (or less) than three agitator blades 20, 21, 22. For example, based on the longitudinal length of the vessel 4, the agitator blades of the second type 21, i.e. the supporting blades, can be absent at all or in a number higher than one, i.e. two, three, etc. For the attachment purposes, it is however important that the mixing unit 2 comprises at least an agitator blade of the first type 20 and an agitator blade of the third type 22.

[0073] Figures 7A-7C illustrate the attachment steps between the agitator blade of the first type 20, i.e. the locking blade, and the supporting rod 3. The figures show a detail of one end of the scraper assembly 1, wherein the scrapper body 5 is in touch with the internal walls 8 of the vessel 5, once the other end of the rod 3 has been coupled with the agitator blade of the third type 22, i.e. once the tapered tip 23 of the rod 3 has been inserted into the through-hole extremity 26 (not shown in the figure). In a first step (figure 7A), the supporting rod 3 is moved close to the locking agitator blade 20. In particular, the recessed portion 16 of the rod 3 is aligned with the protrusions of the C- shaped extremity 24 of the locking blade 20. The alignment is achieved by suitably rotating the rod 3 around the central axis 28 in one direction (i.e. anti-clock wise). Once the recessed portion 16 is aligned with the protrusions of the C-shaped extremity 24, the rod 3 is pushed into the C-shaped extremity 24 (figure 7B). To lock the locking blade 20 with the rod 3, the supporting rod 3 can be further rotated around the central axis 28 in an opposite direction (i.e. clock wise) (figure 7C). In this way, the scraper body 5 of the scraper assembly 1 is firmly kept into contact with the internal walls 8 of the vessel 4 by the action of the biasing bar 13 of the spring member 9 on the front surface 10 of the scraper body 5.

[0074] The steps of figures 7A-7C are better illustrated in figures 8A-8F. Figures 8A, 8C, and 8E are front views of the system scraper assembly 1 / agitator blade 20 relative to the internal wall 8 of the vessel 4 according to the three steps of figures 7A-7C, respectively. On the other hand, figures 8B, 8D, and 8F are the cross sections along the line G-G of figure 8A, along the line F-F of figure 80 and along the line E-E of figure 8E, respectively.

[0075] In the first step (figures 8A and 8B), the supporting rod 3 is rotated in the anticlock direction to allow the recessed portion 16 of the rod 3 to fit the aperture of the C- shaped extremity 24 of the agitator blade of the first type 20. In the second step (figures 80 and 8D), the recessed portion 16 of the rod 3 is inserted (i.e. pushed) into the C-shaped extremity 24 of the locking blade 20. It is noted that by rotating and pushing the rod into the aperture of the extremity 24, the scraper body 5, i.e. the rear surface 43 of the scraper body 5, is also pushed against the internal walls 8 of the vessel 4. In fact, the scraper body 5 is coupled to the spring member 9 that is fixed to the rod 3. Therefore, any movement of the rod 3 will also affect the scraper body 5 through the spring member 9. As a consequence, a reaction force is provided by the walls 8 towards the rear surface 43 of the scraper body 5. This reaction force is transferred to the spring member 9, thereby determining a tension force on the curved portions 35 of the spring member 9. Since the pins 14 of the spring 9 are inserted into the holes 15 of the rod 3, the spring member 9 slightly raises. This is shown in the figures 80 and 8D. In a third step (figures 8E and 8F), the rod 3 is moved back to the initial position, i.e. it is rotated in a clock wise direction, and the tension of the spring member on the curved portions 35 is released. In this case, the recessed portion 16 of the rod 3 is locked inside the aperture of the C-shaped extremity 24 of the locking blade 20.

[0076] As already mentioned, the coupling mechanism among the supporting rod 3, the spring member 9, and the scraper body 5 ensures that the locking between the locking blade 20 and the scraper assembly 1 impacts the scraping action of the scraper body 5 on the internal walls 8 of the vessel 4. On the other way round, the reaction force from the internal walls 8 impacts the scraper body 5, the spring member 9, the supporting rod 3, and consequently the locking with the locking blade 20 due to the torque action on the rod 3.

[0077] In other words, the present configuration improves the locking mechanism between the locking blade 20 and the scraper assembly 1. In fact, by pulling the scraper body 5 upwards from the internal walls 8, a greater tension is created at the spring member 9. Since the supporting rod 3 is prevented from rotating because locked with the locking blade 20, the locking action becomes stronger. By turning the supporting rod 3 in one direction (e.g. clockwise), this rotation tensions the spring 9 harder. By turning the rod 3 in the opposite direction, this rotation unlocks the rod 3 from the locking blade 20. Figure 9A illustrates a detail of the agitator blade of the first type 20. In particular, the lateral view of the C-shaped extremity 24 is shown. The C-shaped extremity 24 has an aperture 32 defined by a hook portion 29 and a base portion 30. The base portion 30 comprises a first flat region 31 facing the hook portion 29 and a second flat region 34 inside the aperture 32. Between the first flat region 31 and the second flat region 34 there is a recess space 33, the first flat region 31 and the second flat region 34 extending on almost the same plane.

[0078] Figures 9B and 9C illustrate the insertion and rotation of the supporting rod 3, i.e. of the recessed portion 16, inside the aperture 32 of the C-shaped extremity 24 of the blade 20. The rod 3 has a circular cross section with a diameter D1 and a recessed portion 16 having a first recess 17 and a second recess 18. The first and second recesses 17, 18 are two opposing flat cut-outs being separated by a distance D2 that is smaller than the rod’s diameter D1 (D2<D1). In order to insert the supporting rod 3 into the aperture 32 of the C-shaped extremity 24, the rod 3 in particular at the recessed portion 16 needs to pass though the opening defined by the hook portion 29 and the base portion 30. Accordingly, the distance D3 between the hook portion 29 and the base portion 30, i.e. the distance between the tip of the hook portion 29 and a line connecting the first flat region 31 with the second flat region 34, is greater (or slightly greater) than the distance D2 between the two recesses 17, 18 (D3>D2). The aperture 32 of the C-shaped extremity 24 has an internal wall 47 with a curved outline to receive the part of the supporting rod 3 without recesses 17, 18 (i.e. curved portion of the rod 3). When the rod 3 is pushed into the aperture 32 (figure 9B), the curved portion of the rod 3 abuts the curved internal wall 47 of the aperture 32, whereas the recessed portions 17, 18 slide on the base portion 30, in particular on the first and second flat regions 31 , 34 and on the tip of the hook portion 29.

[0079] When the supporting rod 3 is rotated (e.g. clockwise), the curved portion of the rod 3 slides on the curved internal wall 47 of the aperture 32 and part of the recesses 17, 18 are engaged with the hook portion 29 and with the recess space 33 of the base portion 30 (figure 9C). It is noted that the recess space 33 has a curved part 48 having the same curvature of the internal wall 47 of the aperture 32 to allow the rotational movement of the rod 3 inside the aperture 32. In particular, the distance between the curved part 48 of the recess space 33 and the curved internal wall 47 of the aperture 32 corresponds to the diameter D1 of the rod 3.

[0080] Figure 10 illustrates a flow diagram of the method 100 for arranging the scraper body 5 in the mixing unit 2. At step S101 , the method 100 comprises mounting the scraper body to the elongated supporting rod 3. This step is described in figure 3B where the rod 3 slides through the attachment portions 11 of the scraper body 5. At step S102, the spring member 9 is fixed to the supporting rod 3. As shown in figure 3C, the holes 15 of the rod 3 are aligned with the pins 14 of the spring member 9 and the spring member 9 is pushed upwards to insert the pins 14 into the holes 15. The method 100 further comprises coupling the spring member 9 to the scraper body 5 to make the scraper body 5 spring-loaded (at step S103). This step is illustrated in figures 3D and 3C, where the scraper body 5 is rotated around the central axis 28 of the rod and is put into contact with the spring member 9 at the biasing bar 13.

[0081] Accordingly, a scraper assembly 1 is formed (at step S104) and can be mounted into the mixing unit 2 according to the procedure illustrated for example in figure 6 (at step

[0082] S105). The step of mounting the scraper assembly 1 into the mixing unit 2 comprises the locking procedure illustrated in detail in figures 7A-C, 8A-F, and 9A-C.

[0083] From the description above follows that, although various embodiments of the invention have been described and shown, the invention is not restricted thereto, but may also be embodied in other ways within the scope of the subject-matter defined in the following claims.

Claims

CLAIMS1. A scraper assembly (1) for a mixing unit (2) having a vessel (4) with internal walls (8), the scraper assembly (1) comprising: an elongated supporting rod (3) configured to be mounted inside the vessel (4); and a scraper body (5) having a first edge (6) and a second edge (7) opposite to the first edge (6), the scraper body (5) being pivotally mountable in a removable way to the supporting rod (3) at the first edge (6) and being configured to scrape the internal walls(8) of the vessel (4) at the second edge (7), wherein the scraper assembly further comprises a spring member (9) fixable to the supporting rod (3) and coupled to the scraper body (5) to make the scraper body (5) spring-loaded.

2. Scraper assembly (1) according to claim 1 , wherein the scraper body (5) comprises an attachment portion (11) at the first edge (6) for the mounting of the scraper body (5) to the supporting rod (3).

3. Scraper assembly (1) according to claim 2, wherein the attachment portion (11) comprises a through-hole (12) for receiving the supporting rod (3).

4. Scraper assembly (1) according to any one of claims 1 to 3, wherein the spring member (9) is in contact with the scraper body (5) to exert a biasing force on the scraper body (5) so that the second edge (7) of the scraper body (5) is kept in contact with the internal walls (8) of the vessel (4) when the supporting rod (3) is mounted inside the vessel (4) of the mixing unit (2).

5. Scraper assembly (1) according to any one of claims 1 to 4, wherein the spring member (9) is a single-piece wire element comprising a biasing bar (13) to be in contact with the scraper body (5) and two connecting pins (14) for fixing the spring member (9) to the supporting rod (3).

6. Scraper assembly (1) according to any one of claims 1 to 5, wherein the supporting rod (3) comprises at least two holes (15) for the fixing of the spring member(9) to the supporting rod (3).

7. Scraper assembly (1) according to any one of claims 1 to 6, wherein the supporting rod (3) comprises at least a recessed portion (16) for being coupled to an internal component of the mixing unit (2).

8. Scraper assembly (1) according to claim 7, wherein the recessed portion(16) comprises a first recess (17) and a second recess (18) opposite to the first recess(17) to be engaged with a C-shaped element.

9. Scraper assembly (1) according to any one of claims 1 to 108 wherein the supporting rod (3) comprises a tapered tip (23) for being inserted into an internal component of the mixing unit (2).

10. Mixing unit (2) comprising: a vessel (4) having inner walls (8) for containing a product to be mixed; a rotating shaft (19) extending longitudinally inside the vessel (4); a plurality of agitator blades (20, 21 , 22) coupled to the shaft (4) and used for mixing the product inside the vessel (4); and at least a scraper assembly (1) according to any one of the preceding claims, the scraper assembly (1) being mounted in a removable way inside the vessel (4) by locking the elongated supporting rod (3) of the scraper assembly (1) to the agitator blades (20, 21 , 22).

11. A scraper body (5) configured to be part of a scraper assembly (1) according to any one of claims 1 to 9.

12. A method (100) of arranging a scraper body (5) in a mixing unit (2), the method (100) comprising: mounting (S101) the scraper body (5) to an elongated supporting rod (3); fixing (S102) a spring member (9) to the supporting rod (3); coupling (S103) the spring member (9) to the scraper body (5) to make the scraper body (5) spring-loaded; forming (S104) a scraper assembly (1) comprising at least the scraper body (5), the supporting rod (3) and the spring member (9); and mounting (S105) the scraper assembly (1) into the mixing unit (2).

13. Method according to claim 14, wherein fixing (S102) the spring member (9) to the supporting rod (3) comprises inserting two connecting pins (14) of the spring member (9) into two corresponding holes (15) of the supporting rod (3) and coupling (S103) the spring member to the scraper body (5) comprises rotating the spring member (9) around a central axis (28) of the supporting rod (3) to interlock the spring member (9) with the scraper body (5) so that any linear movement of the scraper body (5) and of the spring element (9) in the direction of the central axis (28) of the supporting rod (3) is prevented.

14. Method according to any one of claims 12 to claim 13, wherein mounting (S105) the scraper assembly (1) into the mixing unit (2) comprises locking the supporting rod (3) to at least an agitator blade (20) of the mixing unit (2).

15. Method according to claim 14, wherein locking the supporting rod (3) to the agitator blade (20) of the mixing unit (2) comprises inserting a recessed portion (16) of the supporting rod (3) into an extremity (24) of the agitator blade (20) and rotating the supporting rod (3) around its central axis (28) to engage the extremity (24) of the agitator blade (20) with the recessed portion (16) of the supporting rod (3) so that any movement of the supporting rod (3) relative to the agitator blade (20) is prevented when the scraper body (5) of the scraper assembly (1) is in contact with internal walls (8) of the mixing unit (2).

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