Bran-removing perforated cylindrical body of abrasive type grain milling machine

#The present invention relates to a vertical grain milling machine in which grain to be milled is introduced into a cylindrical grain milling chamber from vertical one end of the grain milling chamber and grain having been milled is discharged from the other end of the same, and more particularly, to an abrasive type vertical grain milling machine of the type that comprises a abrasive roll assembly mounted on a main shaft extending straight in the vertical direction and a perforated or porous cylindrical body or cylindirical screen extending vertically around the roll assembly leaving a space therefrom so as to form the cylindrical grain milling chamber around the roll assembly in cooperation with an outer peripheral surface of the roll assembly and having a large number of bran-removing holes or perforations through which bran produced in the grain milling chamber is allowed to be released so that the grain to be milled is introduced into the grain milling chamber from vertical one end of the grain milling chamber and the grain having been milled is discharged from the other end of the same. The invention especially relates to the bran-removing perforated or porous cylindrical body of the abrasive type vertical grain milling machine.

#It is noted that grain to be milled is not limited to rice grain but may be other cereal grain such as wheat grain or coffee bean.

#As described later in connection with FIG. 6, there has conventionally been known an abrasive type vertical grain milling machine in which a cylindrical body or screen comprises for example two or four perforated or porous arcuate plate members having bran-removing perforations or holes formed therein and, in order to lead grain to be milled in a direction from one end toward the other end of a grain milling chamber when the grain is rotated within the grain milling chamber in the direction of rotation of a grain milling roll assembly, each of the bran-removing holes being an elongated hole extending inclinedly in the direction of rotation of the grain milling roll assembly as going from one end toward the other end of the grain milling chamber.

#FIG. 1 is a vertical sectional view of an abrasive type vertical grain milling machine according to a preferred embodiment of the present invention (a sectional view of FIG. 3 taken along a line I--I);

#FIG. 2 is an enlarged sectional view for illustrating a part of the grain milling machine of FIG. 1;

#FIG. 3 is a cross-sectional view of the grain milling machine of FIG. 1 taken along the line III--III of FIG. 1;

#Now, taking a case of whitening rice grain as the grain, an abrasive type vertical rice whitening machine, which is a preferred embodiment of an abrasive type vertical grain milling machine according to the present invention, will be described with reference to FIGS. 1 to 3.

#In FIG. 1 showing generally a vertical sectional view of an abrasive type vertical rice whitening machine 1, reference numeral 2 denotes a base. In the central portion of the base 2, a main shaft 3 formed by a hollow shaft extending in the vertical direction is rotatably supported by means of upper and lower bearings 4 and 5. A motor 6 is equipped sidewards of the base 2 so that rotation of an output shaft 7 of the motor 6 is transmitted through a pulley 8, a wedge belt or V belt 9 and a pulley 10 to the main shaft 3, thereby making the main shaft 3 rotate at a suitable rotational speed (typically at a rotational speed that the speed of an abrasive type roll assembly 16 to be described later becomes about 600 m/min at the outer peripheral surface thereof).

#As shown in FIG. 1 and FIG. 2 showing a part of FIG. 1 on an enlarged scale, a rotary bottom member 11 having a cap-like cross-section is fixed to the main shaft 3 such as to be positioned above the upper bearing 4, and a ring-like support member 13 formed with stirring blades 12 serving to discharge white rice grains, i.e. rice grains having been whitened or milled, is fixed to the rotary bottom member 11.