Abstract:
The present invention relates to a mechanical food treatment processor comprising a driving block topped by a bowl. The driving block comprises a motor connected to a rotation driving means. The processor further comprises a food treatment tool with means of coupling with the rotation driving means. The bowl is topped by a lid with an opening/closing system placed on the bowl and operable to rotate about a substantially vertical axis. The lid is provided with a safety device operable to block the opening of the lid when a force, substantially parallel to the axis of rotation, is exerted on the lid. The claimed device is operable to avoid a brutal ejection of the lid and/or emissions of extreme burning steam in the event of an overpressure in the bowl.

Description:
RELATED APPLICATIONS 
       [0001]    This application claims priority from French Patent Application No. 11 58704 filed Sep. 28, 2011, which is incorporated herein by reference in its entirety. 
       TECHNICAL FILED OF THE INVENTION 
       [0002]    The present invention refers to a mechanical food processor. More precisely, the present invention refers to a food processor such as a blender or a “cutter”. 
       BACKGROUND OF THE INVENTION 
       [0003]    Such a processor is well known in the prior art. It typically comprises a driving block topped by a bowl. The driving block comprises a driving shaft able to rotate about an axis which is vertical or nearly vertical. A treatment tool, generally comprising cutting blades, is placed in the bowl on the driving shaft. The cutting blades can thus ensure the cutting or the mixing of the food placed in the bowl, such as fruits or vegetables. Such a food processor is described for example in document FR2641458. 
         [0004]    In a conventional way, such a processor comprises a lid able to fit the bowl. This lid ensures in particular the user&#39;s safety, by preventing her/him from introducing a limb into the bowl when the treatment tool is working The lid also avoids splashes towards outside, which could prove to be dangerous in the case of a hot preparation. It is indeed possible to provide the bowl with a food heating device. 
         [0005]    It is traditional to provide the lid and/or the bowl with a safety device connected to the power supply for the motor, so that said motor can work only when the lid is in a closing position on the bowl. Such a device is described in particular in documents EP1269898 and FR2890551. 
         [0006]    However, even if the motor stops, accidents can occur when opening the lid. When the rotating processor is working, a column of liquid can be formed inside the bowl, this column needs a few moments for going down again after the motor has stopped. This column of liquid can exert a pressure on the lid. In the same way, heating the contents in the bowl can cause the steam pressure to be risen inside said bowl, when the latter contains a significant quantity of water. 
         [0007]    When a user actuates an unlocking device for the lid, said pressure is released and can brutally eject said lid and/or generate a jet of hot liquid or steam, which is dangerous for the user. 
         [0008]    There is thus a need to make the opening of the lid of such a processor more safe, even if the motor has stopped. 
       OBJECT AND SUMMARY OF THE INVENTION 
       [0009]    An aspect of the present invention enables to solve this problem. Indeed, this aspect of the invention implements a safety device for the opening of the lid, activated when there is a significant overpressure in the bowl. 
         [0010]    More precisely, an object of the present invention is a mechanical food processor, said processor comprising a driving block topped by a bowl, the driving block comprising a motor connected to a rotation driving means, the processor moreover comprising a food treatment tool, provided with means of coupling with the rotation driving means, the bowl being topped by a lid, said lid being provided with a opening/closing system placed on the bowl and able to rotate about a substantially vertical axis, the processor being characterized in that the lid is provided with a safety device allowing to block the opening of the lid when a force, substantially parallel to the axis of rotation, is exerted on said lid. 
         [0011]    By “substantially vertical axis”, one understands that the axis of rotation can be vertical or slightly tilted with respect to the vertical. Preferably, the angle of inclination is not higher than 30°. 
         [0012]    In a preferential way, the lid is able to pivot with respect to the bowl, between a closing position and an opening position, the closing position enabling the motor to work and the opening position enabling to raise the lid; moreover, the opening position is at an angular distance α from the closing position and the safety device comprises a blocking means for blocking the lid in a blocking position at an angular distance β from the closing position, with 0&lt;β&lt;α. 
         [0013]    In a preferential way, the safety device comprises at least one means supported by the bowl, cooperating with at least one means supported by the lid, in order that a rotation of said lid about the axis of rotation is blocked when a force, substantially parallel to said axis, is exerted on said lid. 
         [0014]    In a preferential way, the processor comprises a second safety device which prevents the motor from working when the lid is not in the closing position on the bowl. Such a second device is known from the state of the art, as previously mentioned. 
         [0015]    Preferably, the second safety device prevents the motor from working when the lid deviates by an angle γ from the closing position, with 0≦γ&lt;β. Thus, when the lid reaches the blocking position, the motor necessarily stops. 
         [0016]    In a preferential way, a connection between the bowl and the lid are provided with a seal comprising a substantially cylindrical part disposed along the axis of the bowl, a dimension of said seal along said axis being sufficient to maintain the connection tight when the lid is in the blocking position. Indeed, the blocking position corresponds to a slight heightened position of the lid with respect to the bowl. 
         [0017]    In addition, it can be advantageous to provide the lid with an opening of reduced size with respect to the size of said lid. Such an opening enables to introduce food into the bowl when the treatment tool is working This possibility is advantageous for example when preparing an oil-in-water emulsion, in which fat can be added progressively. 
         [0018]    In a traditional way, the treatment tool is centered with respect to the bowl. It is thus advantageous to place the opening off centre in the lid, in order to prevent the food introduced from falling directly on the tool. 
         [0019]    However, when the treatment tool rotates at a high speed, a column of liquid can be formed along a vertical wall of the bowl. A part of the liquid is then likely to overflow through the off-centre opening. 
         [0020]    Another aspect of the present invention enables to solve this problem. More precisely, another object of the present invention is a mechanical food processor, said processor comprising a driving block topped by a bowl having a substantially cylindrical shape along a substantially vertical axis, the bowl being topped by a lid, the driving block comprising a motor connected to a rotation driving means, the processor moreover comprising a food treatment tool provided with means of coupling with the rotation driving means, the processor being characterized in that: the lid is provided with at least one opening for introducing food into the bowl, said opening being off-centered with respect to the axis of the bowl; an internal wall of the lid supports a surface having a substantially cylindrical shape, oriented towards a periphery of the lid, located between the introduction opening and said periphery of the lid; when the lid is positioned on the bowl, said surface is substantially centered on the axis of the bowl. 
         [0021]    This surface enables to contain a column of liquid formed by centrifugation, so as to avoid an overflow of liquid through the food introduction opening. 
         [0022]    The expression “substantially vertical axis” is understood as previously indicated. 
         [0023]    In a preferential way, an internal side wall of the bowl is located at a radial distance from the surface, said radial distance being selected according to a volume of liquid that can be treated in the bowl. The volume formed by the bowl at this radial distance corresponds preferentially to a maximum volume that can be treated by the processor. 
         [0024]    It is sometimes advantageous to be able to close the food introduction opening in order to have a closed lid. In a preferential way, the lid is thus provided with a shaft mounted so as to rotate about the axis of the bowl, said shaft being firmly fixed to a panel closing the food introduction opening, said panel being configured so as to make said opening alternately open and close when the shaft is rotating. 
         [0025]    In a more preferential way, the shaft mounted on the lid is provided with a handle located outside said lid, said handle being substantially opposite the closing panel. Thus, the opening is closed when the operator&#39;s hand passes above said opening, which avoids possible steam burns. 
         [0026]    According to an embodiment of the invention, the shaft mounted on the lid is provided with a scraping arm able to remove food from an internal side wall of the bowl. Such a scraping arm is known from the state of the art, for example from document FR2605207. A scraping arm can also be designed to remove food from an internal wall of the lid. 
         [0027]    It is advantageous to combine in the same processor the invention concerning the overpressure-related safety device and the invention concerning the food introduction opening. The safety device is particularly useful when the introduction opening is provided with a closing panel. 
         [0028]    In a preferential way, the lid of a processor such as previously described comprises a conduit for evacuating steams from the bowl. Preferentially, said conduit comprises a first end close to a centre of the lid and leading into the bowl, as well as a second end offset from said centre and leading to the outside of the bowl. This embodiment is particularly advantageous when the lid comprises an off-centered food introduction opening provided with a closing shutter. Thus, when said opening is closed, steams can escape through the conduit. 
         [0029]    In a preferential way, a processor as previously described comprises a food heating device. Thus, it combines a mechanical treatment function with a heating and/or cooking function. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0030]    The invention will be better understood when reading the following description and examining the annexed Figures. These Figures are given as an indication and by no means as a restriction of the invention. The Figures show: 
           [0031]      FIG. 1 : a perspective view of a food processor according to an embodiment of the invention; 
           [0032]      FIG. 2 : a partial schematic sectional view of the processor in  FIG. 1 ; 
           [0033]      FIG. 3 : a schematic top view of a food processor according to an embodiment of the invention; 
           [0034]      FIG. 4 : a schematic view of a safety device for a food processor according to an embodiment of the invention; 
           [0035]      FIG. 5 : a sectional view of a lid of a processor according to an embodiment of the invention; and 
           [0036]      FIG. 6 : a sectional view of a lid of a processor according to an embodiment of the invention. 
       
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
       [0037]      FIG. 1  shows a perspective view of a food processor according to an embodiment of the invention. The processor  10  comprises a driving block  11  topped by a bowl  12 . The bowl  12  itself is topped by a lid  13 . The bowl  12  has a substantially cylindrical shape of revolution and is disposed along a substantially vertical axis  14 . 
         [0038]      FIG. 2  represents a partial schematic view of the processor  10  in a vertical sectional passing through the axis  14 . The driving block  11  comprises a motor  15  represented schematically in  FIG. 2 . The motor  15  is connected to a driving means, in fact a driving shaft  16 , having of a substantially cylindrical shape and disposed along the axis  14 . 
         [0039]    A bottom  17  of the bowl  12  comprises an opening  18  allowing the passage of the driving shaft  16 . In the example in  FIG. 2 , the opening  18  is prolonged by a conduit  19 , located inside the bowl  12  and disposed along the axis  14 . 
         [0040]    The processor  10  moreover comprises a food treatment tool, in fact a knife  20 . The knife  20  comprises a support  21  provided with at least one blade  22 . The action of the knife  20  enables in particular to reduce in pieces or in fine particles food introduced into the bowl  12 . 
         [0041]    The support  21  comprises a central cavity  23  having a substantially cylindrical shape, which allows said support to be spanned onto the conduit  19  and the shaft  16 . A bottom  24  of the cavity  23  is provided with means of assembling with an end  25  of the shaft  16 , so that said shaft is able to rotate the knife  20  about the axis  14 . 
         [0042]    In addition, in the example represented in  FIG. 2 , the bowl  12  is provided with a food heating device  26 . The device  26  is fixed for example under the bottom  17 . This device  26  is for example a heating resistance. According to an alternative embodiment, the processor  10  is provided with an induction heating device. 
         [0043]    The device  26  allows to heat or cook the food introduced into the bowl  12 . The combined action of the knife  20  and the device  26  thus allows to carry out hot fluid preparations, such as soups or sauces. 
         [0044]    The power supply of the motor  15  and the heating device  26  can be controlled by a user, via a control panel  27  ( FIG. 1 ) located on the driving block. 
         [0045]      FIG. 1  represents the lid  13  in a so-called closing position on the bowl  12 . Said bowl  12  and said lid  13  are provided with a first safety device  28 , which prevents the motor  15  from working when the lid is not in the closing position on the bowl. The device  28  comprising for example a safety pin (not represented) connected to a switch (not represented), said switch deactivating the power supply of the motor  15  when the lid leaves the closing position. Such a device is described in particular in document FR2890551, which is incorporated herein by reference in its entirety. 
         [0046]    The device  28  can be implemented so that a displacement of the lid  13  from the closing position causes the motor  15  to be stopped. Alternatively, the device  28  can block the lid  13  in the closing position until the motor  15  stops. 
         [0047]    For opening the lid  13  in order to access the contents of the bowl  12 , said lid must be first rotated about the axis  14  from its closing position.  FIG. 3  shows a schematic top view of an processor similar to the processor  10 . 
         [0048]    The lid  13  and the bowl  12  are provided with a second safety device  29 , which prevents in particular the lid  13  from opening too abruptly, in the event of an overpressure on the lid inside the bowl. The device  29  allows in particular to rotate the lid  13  by an angle α about the axis  14  from the opening position, in order to reach a so-called opening position represented in  FIG. 3 . When this opening position is reached, the lid  13  can be raised from the bowl  12  to give access to the inside of the bowl. 
         [0049]    In the event of an overpressure when opening the lid  13 , a second device  29  allows to block said lid in a so-called blocking position, corresponding to a rotation by an angle β about the axis  14  from the closing position. The angle β is higher than 0 and lower than angle α. 
         [0050]      FIG. 4  shows a detailed view of a possible example of configuration of the second safety device  29 . 
         [0051]    One can see the lid  13 , positioned on the bowl  12 . In this example, the lid  13  comprises a substantially cylindrical external shoulder  30  having an axis  14 . When the lid is positioned on the bowl, the shoulder  30  surrounds an external wall  31  of said bowl. 
         [0052]    The shoulder  30  comprises a slit  32  disposed in a plane perpendicular to the axis  14 . The wall  31  comprises a projection  33  having such a configuration that it can slide in the slit  32  when the lid  13  rotates about the axis  14  with respect to the bowl  12 . 
         [0053]    When the lid is in the closing position, the projection  33  is near a first closed end  34  of the slit  32 . When the lid is pivoted in order to reach the opening position, the projection gets close to a second end  35  of said slit. The end  35  comprises an opening  36  leading to a lower edge of the shoulder  30 . When the lid is in the opening position, the projection  33  is opposite the opening  36 . One can thus raise the lid along the axis  14  without said lid not being retained on the bowl by the projection  33 . 
         [0054]    When a column of water in the bowl  12  and/or a steam overpressure is formed, the lid  13  is submitted to an upwards vertical force; it thus tends to be raised during its displacement between the closing and opening positions. To avoid a brutal ejection of the lid and/or an emission of steam or hot liquid, the shoulder  30  comprises a notch  37 , substantially parallel to the axis  14 . Said notch  37  corresponds to the above-mentioned position of the lid, the so-called blocking position. Said notch  37  is provided at a position lower than the slit  32  along the axis  14 . An upper end of said the notch leads into said slit  32 , the other lower end is closed. 
         [0055]    Under the action of the upwards force exerted on the lid during the displacement thereof towards the opening position, the projection  33  enter the notch  37  before reaching the end  35  of the slit  32 . The projection  33  abuts against the lower end of the notch  37 , which prevents the lid from raising. This abutment enables the lid  13  to keep the blocking position. 
         [0056]    If the pressure on the lid is due to steam, the operator can then implement an evacuation of the pressure in the bowl, through means that will be described below. The fall of the pressure enables the lid to go down again so that the projection  33  can carry on moving in the slit  32  towards the opening position. If the pressure is caused by a water column, the lid leaves the blocking position and is controllable again as soon as the liquid goes down again. 
         [0057]    It is obviously possible to configure the device  29  according to a technical solution different from that represented in  FIG. 4 , while remaining within the scope of this invention. 
         [0058]    It is possible that the first of safety device  28  allows a displacement range for the lid from the closing position. More particularly, the first safety device prevents the motor from working when the lid deviates from an angle γ from the closing position, the angle γ being superior or equal to 0. Preferably, γ is lower than β. Thus, when the lid reaches the blocking position, the motor necessarily stops. 
         [0059]    Preferentially, as in the embodiment represented in  FIG. 2 , a connection between the bowl  12  and the lid  13  is provided with a seal  40 . The seal  40  comprises a substantially cylindrical part  41 , disposed along the axis  14  when the lid is in the closing position. An external surface of the part  41  comes into contact with internal walls of the bowl and the lid and exerts a radial pressure on said internal walls. 
         [0060]    The joint  40  is configured so that a dimension  42  of the part  41  along the axis  14  is sufficient to maintain the tightness when the lid is in the blocking position, i.e. for example when the projection  33  ( FIG. 4 ) abuts against the lower end of the notch  37 . When the safety device  29  has the configuration represented in  FIG. 4 , the dimension  42  thus corresponds at least to the depth of the notch  37  along the axis  14 . 
         [0061]    In a preferential way, a contact surface between the lid  13  and the seal  40  substantially have the same diameter as the bowl  12 . Preferentially, the seal  40  has a plane of symmetry which is substantially perpendicular to the axis  14 , so as to be able to be assembled with the unit bowl/lid in two possible positions. 
         [0062]    In the embodiment represented in  FIGS. 1 and 2 , for eliminating an overpressure in the bowl  12  when the lid  13  is blocked as previously described, the operator can open an opening  43  located on said lid. 
         [0063]    One of the functions of the opening  43  is to allow the introduction of food into the bowl  12  when the motor  15  is working The opening  43  is advantageously off-centered with respect to the axis  14 , so that the food falls in the preparation and not on the knife  20 . 
         [0064]      FIG. 5  shows a sectional view of the lid  13  of the processor in  FIG. 1 . The opening  43  can be opened or closed by means of a closing panel  44 . When the lid  13  is positioned on the bowl  12 , the panel  44  is inside the volume delimited by the unit bowl/lid. 
         [0065]    Preferentially, the panel  44  is mounted on the lid  13  so as to rotate about the axis  14 . The panel  44  is for example firmly fixed to a shaft  45  mounted in a housing  46  of the lid  13 . The housing  46  is coaxial with the axis  14 . The shaft  45  is connected to a handle  47  located outside the lid  13 , which allows the user to rotate the shaft  45  manually. The panel  44  preferably has a surface slightly higher than the opening  43 , but is not rotational symmetrical with respect to the axis  14 . Thus, when rotating the handle  47 , one alternately opens and closes the opening  43 . 
         [0066]    Preferably, the panel  44  is opposite the handle  47  with respect to a plane perpendicular to the axis  14 . Thus, when the handle  47  is perpendicular to the opening  43 , this opening is closed by the panel  44 . This configuration prevent the operator from being burned by the steam going out through the opening, in particular when the food heating device  26  is working. 
         [0067]    The shaft  45  can also be connected to a scraping arm  48  whose function is to remove food from an internal side wall  49  ( FIG. 2 ) of the bowl  12  in order to bring them back to the knife  20 . The arm  48  can be operated by the user by means of the handle  47 . The panel  44  thus prevents the user using the arm  48  from being burned. 
         [0068]    When a liquid preparation is contained in the bowl  12 , the fast rotation of the knife  20  ( FIG. 2 ) can cause the formation of a water column along the wall  49  of said bowl. There is then a risk of overflow of liquid through the off-centered opening  43 , when the latter is not closed by the panel  44 . 
         [0069]    In order to prevent such an overflow, a internal wall  50  of the lid  13  supports a surface  51  having a substantially cylindrical shape along the axis  14 . 
         [0070]    The surface  51  is oriented towards a periphery of the lid and is located between said periphery and the opening  43 . Preferentially, as in  FIG. 2 , the surface  51  is tangential to a edge  52  of the opening  43 , close to the periphery of the lid. 
         [0071]    The function of the surface  51  is to retain an upper part of a column of liquid formed by centrifugation of the contents in the bowl  12 . The surface  51  prevents in particular the liquid from leaking through the opening  43  when the latter is not closed. 
         [0072]    Advantageously, the surface  51  and the wall  49  of the bowl are at a radial distance  53  from each other, selected according to a maximum volume of liquid that can be treated by the processor  10 . 
         [0073]      FIG. 6  shows a sectional view of the lid  13  in  FIG. 1 , according to a plane perpendicular to that in  FIG. 5 . 
         [0074]    In order to limit to the maximum the cases of overpressure in the bowl, even when the opening  43  is closed, the lid  13  is provided with a conduit  54  for evacuating steams. The conduit comprises an input  55 , close to the axis  14  and leading into the interior of the bowl. In the example in  FIG. 6 , the input  55  is formed by a channel inside the shaft  45 . 
         [0075]    The conduit moreover comprises an output  56  which is off-centered with respect to the axis  14  and leads to the outside of the lid  13 .