Abstract:
A laboratory apparatus for grinding loose materials, comprising a frame for supporting a shaft that is mounted for rotation about its own axis and is associated with a corresponding motor actuation and with supports for supporting a container that has at least one opening for introducing and withdrawing the materials and is arranged eccentrically with respect to the shaft; the container is adapted to assume at least one active configuration, in which it traces an orbit around the shaft, which is rotationally actuated, and at least one inactive configuration for introducing the materials to be ground and/or for withdrawing the ground materials.

Description:
[0001]    The present invention relates to a laboratory apparatus for grinding loose materials.  
         BACKGROUND OF THE INVENTION  
         [0002]    Laboratories for the testing, research, control and development of several types of new or existing products, such as raw materials, enamels, screen printing pastes, mixes, dyes and the like, are known in the ceramics field.  
           [0003]    The preparation of test samples generally entails a step for grinding and homogenizing the loose materials that compose the product to be tested.  
           [0004]    Known types of laboratory apparatus for grinding loose materials are substantially constituted by a cabinet provided with an opening and closure door, which contains one or more rotation devices, each suitable to cause the rotation of a respective jar about a vertical axis.  
           [0005]    Each jar comprises a container, provided with a mouth for introducing and withdrawing the materials, a plug for closing the mouth, and a charge of grinding media, constituted by beads.  
           [0006]    These laboratory apparatuses, however, are not devoid of drawbacks, including the fact that the structure of the cabinets and the manual handling of the jars limit the dimensions and the capacity of the jars that can be used; this accordingly prevents the production of homogeneous test samples in quantities greater than those obtainable from a single jar.  
           [0007]    It is noted that if it is necessary to prepare a test sample in quantities exceeding the actual capacity of a single jar, one grinds separately, by using a plurality of jars, quantities that are submultiples of the required quantity, each having the same composition and formulation as the sample.  
           [0008]    Because of the possible human, instrument and environmental errors that are associated with any laboratory test, the compositions of the prepared submultiple quantities can be different one another, with their own grinding charges, with the risk of biasing the results of the tests being performed.  
           [0009]    Another drawback of known apparatuses is that they require awkward and repeated manual operations for carrying, mounting and removing the jars from the cabinets, with consequent waste of time, human resources and costs.  
           [0010]    In fact, technicians prepare each jar with the material to be ground, mount it and fix it inside the cabinet and, at the end of the grinding process, release it and remove it from the cabinet in order to withdraw the ground material therefrom.  
         SUMMARY OF THE INVENTION  
         [0011]    The aim of the present invention is to eliminate the above noted drawbacks of conventional apparatus by providing a laboratory apparatus for grinding loose materials that allows to prepare homogeneous test samples, does not require the execution of mounting and removal operations at each grinding cycle, and allows to improve the use of human resources and time utilization.  
           [0012]    Within this aim, an object of the present invention is to provide a structure that is simple, relatively easy to provide in practice, safe in use, effective in operation, and relatively low in cost.  
           [0013]    This aim and this and other objects that will become better apparent hereinafter are achieved by the present laboratory apparatus for grinding loose materials, characterized in that it comprises a frame for supporting a shaft that is mounted for rotation about its own rotation axis and is connected to corresponding motor means and with supporting means for supporting a container that has at least one mouth for introducing and withdrawing the materials and is arranged eccentrically with respect to said shaft, the container being provided so as to assume at least one active configuration, in which it traces an orbit around the shaft, which is rotationally actuated, and at least one inactive configuration for introducing the materials to be ground and/or for withdrawing the ground materials.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0014]    Further characteristics and advantages of the present invention will become better apparent from the detailed description of a preferred but not exclusive embodiment of a laboratory apparatus for grinding loose materials, illustrated only by way of non-limitative example in the accompanying drawings, wherein:  
         [0015]    [0015]FIG. 1 is a schematic axonometric view of an apparatus according to the invention;  
         [0016]    [0016]FIG. 2 is a schematic side view of FIG. 1;  
         [0017]    [0017]FIG. 3 is a schematic front view of FIG. 1;  
         [0018]    [0018]FIG. 4 is a schematic enlarged-scale view of a detail of the apparatus according to the invention;  
         [0019]    [0019]FIG. 5 is a schematic sectional view of FIG. 4. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0020]    With reference to the figures, the reference numeral  1  generally designates a laboratory apparatus for grinding loose materials.  
         [0021]    The apparatus  1  comprises a supporting frame  2 , with which a shaft  3  rotatable about its own axis A is associated; motor means  4 , which are suitable to turn the shaft  3 ; and supporting means  5 , associated for joint movement with the shaft  3 , for supporting a grinding container  6 .  
         [0022]    The container  6  is constituted by a globular body that is substantially symmetrical with respect to a longitudinal axis B and tapers into a neck in which there is an opening  7  for introducing the materials to be ground and for withdrawing the ground materials.  
         [0023]    The container  6 , moreover, is provided with a closure plug and with a screening grate that is associated with the opening  7 ; in a possible embodiment, the grate can be formed monolithically with the plug.  
         [0024]    The container  6  is arranged so that its axis B lies in an eccentric position with respect to the axis A of the shaft  3 .  
         [0025]    In the active configuration, the shaft  3  is rotationally actuated by the motor means  4  and the container  6  traces a circular orbit around the axis A for grinding the materials introduced therein; in the inactive configuration, the shaft  3  is motionless and allows to introduce the materials to be ground in the container  6  or to withdraw the ground materials therefrom.  
         [0026]    The supporting means  5  are constituted by a plate-like base  8 , coupled for joint motion to one end of the shaft  3 , by a support  9 , which is associated with the base  8 , and by a framework  10  that supports the container  6 .  
         [0027]    Means for adjusting the eccentricity of the container  6  are interposed between the base  8  and the support  9  and are constituted by a clamp-like support  11 , which is coupled to the base  8 , and by an arm  12 , which lies transversely to the shaft  3  and is inserted slidingly between the jaws of the support  11 , its two ends supporting respectively the support  9  and a counterweight  13 .  
         [0028]    The sliding of the arm  12  with respect to the support  11  allows to adjust the eccentricity or distance of the axis B of the container  6  with respect to the axis A of the shaft  2 ; the arm  12  is locked by way of fixing or locking means constituted by screws  14  for tightening the two jaws of the support  11 .  
         [0029]    The framework  10  is articulated, so that it can oscillate about a first axis C that is not parallel, but contained in a plane perpendicular to the axis A of the shaft  3 , to the support  9  by way of first articulation means, constituted by a first cylindrical hinge  15 .  
         [0030]    The hinge  15  allows to incline the framework  10  and therefore the axis B of the container  6  with respect to the axis A of the shaft  3 .  
         [0031]    In the active configuration, the axis B of the container  6  is inclined with respect to the axis A of the shaft  3  by an angle α of 0 to 45 sexagesimal degrees.  
         [0032]    Advantageously, the breadth of the angle α is substantially equal to 20 sexagesimal degrees.  
         [0033]    The framework  10  is constituted by a C-shaped bracket  16  in which the concave side is orientated so as to wrap around the container  6  and the convex side has a shank  17  that is articulated to the support  9  by means of the first hinge  15 .  
         [0034]    The apparatus  1  further comprises means  18  for anchoring the container  6  to the supporting means  5 .  
         [0035]    The anchoring means  18  are of the clamp type and comprise: a first jaw, constituted by a first ring  19  that is associable with the framework  10 ; a second jaw, which is constituted by a second ring  20  that is detachably associable with the first one; and means for coupling and uncoupling the second ring  20  with respect to the first ring  19 , which are constituted by a plurality of screws  21 .  
         [0036]    The container  6  is provided with grip protrusions that are constituted by an annular ridge  22  that is shaped in relief on its outer lateral surface and can be inserted and secured within the two rings  19  and  20 .  
         [0037]    Along the grip faces of the rings  19  and  20  there are respective seats  23  and  24  for supporting and clamping the ridge  22 ; conveniently, the ridge  22  is formed proximate to the equatorial line of the body of the container  6 .  
         [0038]    The container  6  is articulated to the framework  10  so that it oscillates about a second axis D, which is not parallel, but contained in a plane perpendicular to the axis A of the shaft  3 , by way of second articulation means, which are constituted by a second cylindrical hinge  25 .  
         [0039]    Second means  26  for locking the oscillation of the container  6  with respect to the framework  10  are provided.  
         [0040]    In the inactive configuration, the second hinge  25  allows to position the container  6  so that the opening  7  is directed upward in order to introduce the materials to be ground or so that the opening  7  is directed downward in order to withdraw the ground materials.  
         [0041]    The second hinge  25  is constituted by two opposite pivots  27 , whose respective ends are rigidly coupled to the outer edge of the first ring  19  and whose opposite ends are inserted rotatably in corresponding seats  28  formed in the framework  10 .  
         [0042]    The second locking means  26  are constituted by a plate  29 , which is rigidly associated with the first ring or jaw  19 .  
         [0043]    The plate  29  has three reference holes  30 ,  31  and  32 , which form respectively the active configuration and the two inactive configurations for withdrawing and introducing the materials in the container  6 .  
         [0044]    A locking pin  33 , accommodated in a through hole  34  of the framework  10 , can be inserted in one of the holes  30 ,  31  and  32  in order to block the oscillation of the container  6  about the axis D.  
         [0045]    Advantageously, the axes C and D are substantially parallel one another and transverse to the axis A of the shaft  3 .  
         [0046]    The motor means  4  are constituted by a motor  35  and by transmission means such as a belt  36  wound in a loop around a driving pulley  37 , which is rigidly coupled to the driving shaft  38 , and a driven pulley  39 .  
         [0047]    The apparatus  1  further comprises a structure  40  for supporting the framework  10  that allows to balance said framework  10  and guide it in its rotary motion.  
         [0048]    The structure  40  is constituted by a portal  41 , which is fixed to the frame  2  and to which the end  42   a  of a swinging bracket  42  is articulated so that it oscillates about an axis E; the opposite end  42   b  of said bracket is articulated, so as to oscillate about an axis F, to a sort of articulated parallelogram.  
         [0049]    The parallelogram is formed by two pairs of linkages  43  and  44 , which are parallel and are articulated to the end  42   b  about first pivots  45  and to the framework  10  about second pivots  46 .  
         [0050]    The apparatus  1  further comprises means for damping the vibrations generated in the active configuration; said means are constituted for example by shock-absorbing means associated with the ground supporting feet  47  of the frame  2 .  
         [0051]    It is noted that the counterweight  13  also has a vibration-damping function.  
         [0052]    In practice it has been found that the described invention achieves the intended aim and objects.  
         [0053]    Finally, the apparatus according to the invention can be inserted and used in an actual production system.  
         [0054]    The invention thus conceived is susceptible of numerous modifications and variations, all of which are within the scope of the appended claims.  
         [0055]    All the details may further be replaced with other technically equivalent ones.  
         [0056]    In practice, the materials used, as well as the shapes and the dimensions, may be any according to requirements without thereby abandoning the scope of the appended claims.  
         [0057]    The disclosures in Italian Patent Application No. MO2001A000218 from which this application claims priority are incorporated herein by reference.