EP2691185B1

EP2691185B1 - Sieve carrier frame

Info

Publication number: EP2691185B1
Application number: EP12710329.9A
Authority: EP
Inventors: Adriano Nalon
Original assignee: OMAS Srl
Current assignee: OMAS Srl
Priority date: 2011-03-28
Filing date: 2012-02-14
Publication date: 2014-12-17
Anticipated expiration: 2032-02-14
Also published as: CN103619494B; BR112013024577A2; CN103619494A; BR112013024577B1; EP2691185A1; WO2012131500A1; ITPD20110094A1

Description

The present patent concerns vibrating sieves for flour, and in particular it concerns a sieve carrier frame.
Systems for sieving flour are known, which are suited to sort flour in fractions having different particle size and to prevent the formation of clots. Vibrating sieves are known which comprise a frame for supporting a plurality of sieves placed on top of one another to form one or more piles, wherein the sieves in higher position have larger meshes than the sieves in lower position.
Said frame is constituted by sections rigidly constrained to one another and is connected to moving devices that produce a vibrating motion of the frame, and thus of the sieves.
The frame is suspended from a rigid bearing structure by means of glass fibre or natural fibre rods that insulate the bearing structure from the vibrations produced by the machine.
Each sieve comprises a sieve carrier frame, substantially square or rectangular in shape, suited to be constrained to the frame of the machine body.
Said sieve carrier frame is provided with a holed fabric or a mesh net that defines the sieving surface.
Beside this fabric or net of each sieve there is also an opening or window suited to allow the unsieved flour to fall down.
In the vibrating sieves of known type the flour is loaded from above and progressively sieved by the different sieves, and each sieve allows the fraction whose particle size is smaller than the holes provided in the fabric to fall down, while it holds the fraction with larger particle size.
In particular, the fine fraction passes through said fabric and falls onto an underlying base of the sieve carrier frame, which has the function of conveying it and unloading it on one side of said base, from where the flour can be conveyed through a channel to the machine discharge opening or another sieving passage situated at a lower level, while the coarse fraction that would accumulate on said net is dropped through said side dropping window due to the effect of the vibrations generated by the machine.
The unsieved flour is generally conveyed into another sieve, until the remaining fraction is constituted by bran only, which is then conveyed to other machines for a further sorting process.
In order to obtain the pile of sieves it is thus necessary to make the sieves one by one, wherein each holed fabric or net with meshes in the right size must be mounted in a fixed manner on a frame made of specifically shaped and sized sections.
In case of breakage of said fabric it is possible to easily replace the sieve carrier frame with an interchangeable one, thus making it possible to replace the damaged fabric or net on the removed frame.
Furthermore, for each type of machine it is necessary to design in advance the number and arrangement of the sieves, in order to be able to make the pile of sieves.
US 2007/108107 relates to a sieve carrier frame for vibrating sieves comprising a square structure defining a sieving area and one or more side windows for discharging the unsieved flour, but no further frame for collecting the sieved flour and/or opening for discharging the sieved flour are disclosed.
The subject of the present invention is a new type of modular sieve that can be put together according to the grinding program to be followed.
The main object of the present invention is to provide a sieve that is completely modular, in which each part is interchangeable or suited to be assembled in different ways, so that it can be put together according to the structure of the sieve pile to be obtained.
It is another object of the present invention to provide a sieve that allows just one or several of the parts that make it up to be replaced in order to vary its position in the pile of sieves or to replace damaged parts with other ready-to-use and interchangeable frames, which allows any damaged sieve to be repaired with no need for long stops of the grinding system.
It is another object of the present invention to facilitate the construction of the parts that make up the sieve by means of simple operations and with no need for expensive equipment.
These and other direct and complementary objects are achieved by the new sieve carrier frame whose main parts comprise:

an upper small frame, in turn comprising several perimeter sections for the installation of the net or the holed fabric so as to form the sieving surface, and one or more further sections defining at least one side flour dropping window for the unsieved flour,
a lower base suited to be coupled to the underside of said small frame and in turn comprising several perimeter sections defining the perimeter of the base itself, corresponding to the external perimeter of said small frame, and at least one plane or tray for collecting the sieved flour, with shape and size corresponding to said sieving surface of the small frame and installed on said sections in a position underlying said sieving surface itself, defining together with said sections a side flour dropping window substantially corresponding to said flour dropping window of said upper small frame,

For example, said spaced section can be shorter than the other perimeter sections, in such a way as to be raised with respect to the corresponding opposite section of said base.
The flour that falls on the sieving surface is then sorted so as to obtain a fine fraction that passes through the fabric and falls onto said tray, and a coarser fraction that accumulates on the fabric itself.
Due to the effect of the vibrations generated by the machine, the fine sieved fraction that has accumulated on said plane or tray of the base is unloaded through said discharge opening, for example onto the underlying sieve, while the coarse fraction that has accumulated on the fabric falls laterally through said flour dropping window, for example into a dedicated container. Said opening for discharging the sieved flour, in particular, is not on the same side as said flour dropping window.
Said discharge opening can for example be located on one or both of the sides adjacent to the side where the flour dropping window is positioned and/or on the opposite side, depending on the configuration and structure of the pile of sieves and of the machine.
Therefore, using the same sections and components, assembled in a different manner, it is possible to obtain sieves whose discharge opening can be located on one or more different sides.
Furthermore, said base can be coupled to any one of said small frames, said base and said small frame being mutually arranged according to any orientation, so that it is possible to obtain sieve carrier frames with flour dropping windows and discharge openings facing towards any side, depending on the construction needs.
The composition and construction of the sieve carrier frames and of the pile that makes up the sieving channel is thus completely modular. In practice, with just a few types of small frames and the same number of bases put together in different ways it is possible to obtain a wide variety of sieving modes of the product passing therethrough. Therefore, it is also possible to keep some predefined types of frame in stock in order to complete them at a later moment with a sieving net or fabric when the final machine has to be set up, depending on design needs.
A further advantage offered by the present invention lies in that it facilitates the procurement and supply of the materials with which the frames are made, as standard sections easily available on the market are used.
The modularity of the system also brings the advantage of improving production, standardizing the frame construction process.
Said sections making up said small frame and said base are substantially tubular and have a box-shaped cross section to lighten the device, and furthermore properly shaped elements made of a plastic material serve the double function of closing the sections and connecting them with the purpose of making the actual frame.
Said sections are furthermore shaped specifically for this type of assembly, as described and claimed here below.
The characteristics of the new sieve carrier frame will be highlighted in greater detail in the following description, with reference to the drawings attached as non-limiting examples.

Figures 1, 2, 3 and 4 show three-dimensional views of four versions of a small frame (A, B, C, D) provided with a flour dropping window (E) and respectively shaped so as to discharge (F) the sieved flour to the right and to the left (A), only to the left (B), only to the right (C) and to the centre (D).
Figure 5 schematically shows a three-dimensional view of a base (G) with a plane or tray (H) suited to collect the sieved flour and a flour dropping window (J).
Figure 6 shows a three-dimensional view of the new sieve carrier frame (K) completely assembled, obtained by superimposing and coupling a small frame (B), for example the one with discharge opening (F) on the left, to a base (G).
Figure 7 shows a section a-a of the sieve carrier frame (K) of Figure 6, while the two Figures 8 and 9 show two details of the same.
Figure 10 shows a side view of a stiffening section (4) of the upper small frame (A, B, C, D).
Figure 11 shows a three-dimensional view of a sieve carrier frame (K) with double flour dropping window (E, J), for example on two adjacent sides of the upper small frame (M) and of the lower base (N).

As schematically shown in Figure 6, the new sieve carrier frame (K) comprises an upper small frame (A, B, C, D) and a lower base (G).
Said upper small frame (A, B, C, D) comprises sections (1, 2, 3, 4) of various types, suited to form a supporting frame for a fabric or mesh net for sieving, not shown in the figure.
In the examples shown in Figures 1, 2, 3, 4, said small frame (A, B, C, D) is substantially rectangular or square in shape and comprises at least four perimeter sections (1, 3) assembled together to form the substantially rectangular or square profile of a sieving surface (L).
Said small frame (A, B, C, D) also comprises one or more further sections (1,2) defining a side flour dropping window (E) for the unsieved flour.
The new sieve carrier frame (K) also comprises at least one lower base (G), illustrated in detail in Figure 5, suited to be coupled to the underside of one of said small frames (A, B, C, D), as shown in Figure 6.
Said base (G) is suited to be coupled to any of said small frames (A, B, C, D) by means of a coupling profile (5), visible for example in Figures 5 and 7 and, in detail, in Figure 9.
Said base (G), including any flour dropping windows (J), has a substantially rectangular or square shape corresponding to the shape of said small frame (A, B, C, D) and in turn comprises at least four perimeter sections (1) and at least one plane or tray (H) for collecting the sieved flour, with shape and size corresponding to those of said sieving surface (L) of the small frame (A, B, C, D).
Said plane or sieve (H) preferably consists of a plate, preferably in stainless steel, or a generically flat body installed on said sections (1) in a position corresponding to that of said sieving surface (L) of the upper small frame (A, B, C, D), thus defining a side flour dropping window (J) substantially corresponding to said flour dropping window (E) of said upper small frame (A, B, C, D).
As shown in Figure 11, according to the invention the small frame (M) and the base (N) may comprise two of said side flour dropping windows (E, J) on adjacent sides.
Said sections (1, 2, 3, 4, 5) are preferably obtained by extruding, for example, aluminium or steel in specific shapes.
In particular, the portions intended to come in direct contact with food substances, meaning said sections, are made with anodized and passivated aluminium. The base frame is preferable made of passivated aluminium and/or stainless steel, while the various parts are assembled together preferably using a double-component epoxy glue and screws for assembly with no welds.
The selected materials are suited to be used at various temperatures and humidity rates, being rather insensitive to said parameters.
Each one of said small frames (A, B, C, D) comprises at least one of said main delimiting sections (1) between said sieving surface (L) and said side flour dropping window (E), and at least one discharge section (3) on an adjacent side, right and/or left, and/or on the side opposite said side flour dropping window (E) and defining, with said base (G), one or more of said discharge openings (F).
In particular, each one of said small frames (A, B, C, D) comprises at least three main sections (1), parallel to each other, two of which define two opposite perimeter sides while the third one defines said side flour dropping window (E).
Said side flour dropping window (E) is also delimited on the other two sides by further closing sections (2).
Said main sections (1), shown in cross section in Figures 8 and 9, are tubular and have a box-shaped cross section, preferably substantially rectangular.
Said cross section is provided with a seat (11) suited to be used for assembling the various parts of said sieve carrier frame (K).
Said base (G) comprises four of said main sections (1) forming the perimeter of the base (G).
Said plane or tray (H) is constrained to three adjacent main sections (1) through a bending operation and the insertion of the corresponding three edges (H1) in said seat (11) in the sections (1).
At the level of the fourth free edge (H2) of said plane or tray (H) there is preferably a further coupling section (5) for assembling a small frame (A, B, C, D) on said base (G).
As is visible in detail in Figure 9, said coupling section (5) has a substantially L-shaped cross section, wherein a first side (51) is constrained to said tray (H) of said base (G) at the height of its free edge (H2), while the second side (52) is suited to be inserted and constrained in said seat (11) in the main section (1) of the superimposed small frame (A, B, C, D).
Each one of said small frames (A, B. C, D) also comprises one or more perimeter discharge sections (3) defining one or more perimeter edges of the small frame (A, B, C, D) and specifically shaped to allow the sieved flour to be discharged.
As can be seen in Figure 1, for example, the small frame (A) comprises three of said main sections (1) over its whole height, suited to be juxtaposed in contact with the corresponding sections (1, 5) of said lower base (G) as shown in Figure 7, and two of said perimeter discharge sections (3) in opposite positions, and shorter in height than said main sections (1), in such a way as to be spaced from the corresponding main section (1) of said base (G), thus defining a discharge opening (F) for the sieved flour, as can be seen in Figure 6.
When assembled onto the base (G), said small frame (A) thus forms a sieve carrier frame (K) with two opposite discharge openings (F), on the right and on the left with respect to said flour dropping window (E).
Figures 2, 3 and 4, instead, show other three examples of a small frame (B, C, D) where said short discharge section (3) is installed respectively on the left, on the right and opposite said flour dropping window (E), thus creating a discharge opening (F) respectively on the left, on the right and opposite said flour dropping window (E).
Said short discharge sections (3), for example, have a substantially rectangular or square cross section.
Said main sections (1) and/or said discharge sections (3) may come in different heights, in such a way as to make discharge openings (F) in different heights, always according to the construction needs, the height of said discharge openings (F) being defined by the difference in height between said main sections (1) and said discharge sections (3).
Said small frames (A, B, C, D) also comprise one or more transverse stiffening and supporting sections (4), shown for example in Figure 10, provided with recesses, seats or grooves (41) for their assembly.
Therefore, with reference to the above description and the attached drawings, the following claims are expressed.

Claims

Sieve carrier frame (K) for vibrating sieves, comprising a plurality of sections (1, 2, 3, 4) assembled together in such a way as to form a substantially square or rectangular structure and defining a sieving area (L), in which it is possible to house a holed fabric or a mesh net, and at least one side flour dropping window (E) suited to allow the unsieved flour to fall down, characterized in that it comprises:
• an upper small frame (A, B, C, D, M) in turn comprising at least four perimeter sections (1, 3) forming the perimeter of said sieving surface (L), and one or more further sections (1, 2) defining at least one side window (E) suited to allow the unsieved flour to fall down;

• a lower base (G, N) whose shape corresponds to the shape of said small frame (A, B, C, D, M), suited to be coupled to the underside of said small frame (A, B, C, D, M) and in turn comprising at least four perimeter sections (1) corresponding to the external perimeter of said small frame, and at least one plane or tray (H) for collecting the sieved flour, installed in a position corresponding to the position of said sieving surface (L) of the upper small frame (A, B, C, D, M), thus defining at least one side flour dropping window (J) substantially corresponding to said flour dropping window (E) of said upper small frame (A, B, C, D, M),
and wherein one or more of said perimeter sections (3) of the sieving surface (L) of said upper small frame (A, B, C, D, M) is spaced from the corresponding opposite perimeter section (1) of said base (G, N), defining at least one opening (F) for discharging the sieved flour.
Sieve carrier frame (K) according to claim 1, characterized in that said spaced section or discharging section (3) has a reduced height compared to the other perimeter sections or main sections (1), in such a way as to be raised with respect to the corresponding opposite section (1) of said base (G, N), thus defining said opening (F) for discharging the sieved flour.
Sieve carrier frame (K) according to claim 2, characterized in that the height of said opening (F) for discharging the sieved flour varies according to the height of said main sections (1) and/or to the height of said discharging sections (3) of said small frames (A, B, C, D, M).
Sieve carrier frame (K) according to claims 1, 2, 3, characterized in that each one of said main sections (1) is tubular and has a box-shaped cross section, with at least one seat (11) for the assembly.
Sieve carrier frame (K) according to the preceding claims, characterized in that each one of said small frames (A, B, C, D, M) comprises at least one of said main delimiting sections (1) between said sieving surface (L) and one or more of said side flour dropping windows (E), and at least one of said discharging sections (3) on an adjacent side, on the right and/or left, and/or on the side opposite said side flour dropping window/windows (E) and defining, with said base (G, N), one or more of said discharge openings (F).
Sieve carrier frame (K) according to claim 5, characterized in that said small frame (M) and said base (N) comprise two of said side windows (E, J) each, in corresponding positions.
Sieve carrier frame (K) according to claims 5, 6, characterized in that said base (G, N) comprises four of said main sections (1) forming the perimeter of the base (G, N), said plane or tray (H) being constrained to one or more of said main sections (1) through a bending operation and the insertion of one or more corresponding edges (H1) of the tray (H) in said seat (11) of the main sections (1), while one or more free edges (H2) of said tray (H) define, together with one or more corresponding spaced main sections (1), one or more of said side flour dropping windows (J).
Sieve carrier frame (K) according to claim 7, characterized in that said base (G, N) comprises, at the level of the free edge/edges (H2) of said plane or tray (H), a further coupling profile (5) for the assembly of an upper small frame (A, B, C, D, M) on said base (G, N), wherein said coupling profile (5) has a substantially L-shaped cross section, with a first side (51) constrained to said tray (H) at the level of said free edge (H2), while the second side (52) is suited to be inserted in and constrained to said seat (11) in the main section (1) of the superimposed small frame (A, B, C, D, M).
Sieve carrier frame (K) according to the preceding claims, characterized in that said small frames (A, B, C, D, M) and/or said base (G, N) also comprise one or more further transverse stiffening and supporting sections (4) provided with recesses, seats or grooves (41) for their assembly.
Sieve carrier frame (K) according to the preceding claims, characterized in that said base (G, N) can be coupled with any of said small frames (A, B, C, D, M) with any orientation.