US3764079A

US3764079A - Roller or ball mill for the refining of cocoa and chocolate and the grinding of paints, enamels and the like

Info

Publication number: US3764079A
Application number: US00193648A
Authority: US
Inventors: C Consoli
Original assignee: Individual
Current assignee: Individual
Priority date: 1971-07-10
Filing date: 1971-10-29
Publication date: 1973-10-09
Anticipated expiration: 1990-10-09
Also published as: AU3785272A; DK147615B; IT968032B; DE2152218A1; BR7108003D0; FR2145899A6; AT325399B; SU464089A3; NL7116073A; JPS5614343B1; CA934348A; ES396321A2; GB1368334A; BE775512A; DK147615C

Abstract

A mill for the refining of cocoa and chocolate and the grinding of paints, enamels and the like which consists of an outer tubular stator and an inner rotor revolvable in the stator. Forks are provided on the outer wall of the rotor for supporting rollers for rotation while permitting the rollers to be urged outwardly when the rotor turns so that the rollers ride on the inner surface of the stator. The rollers as thus supported are arranged in a spiral path along the outer wall of the rotor. The rollers are formed with separate grooves which define spiral ribs running from end to end of the rollers. The corners of the ribs are sharp and are maintained sharp by riding on the inner surface of the stator.

Description

United States Patent Consoli Oct. 9, 1973 ROLLER 0R BALL MILL FOR THE 1,736,394 11/1929 Dierker 241/161 REFINING- 0F COCOA AND CHOCOLATE 2,413,793 l/l947 Sharp 241/131 X AND THE GRINDING 0F PAINTS,

ENAMELS AND THE LIKE l Claudio C. Consoli, Via Neera 39, Milan, Italy Filed: Oct. 29, 1971 Appl. N0.: 193,648

Foreign Application Priority Data Inventor:

Field of Search 241/103, 105, 106, 241/110, 115,118, 161-163, 123, 131, 228

References Cited UNITED STATES PATENTS 6/1918 Grassl 241/123 l/l95l Vincent 241/118 Primary Examiner-Donald G. Kelly Att0rney-Morris Kirschstein et a1.

[57] ABSTRACT A mill for the refining of cocoa and chocolate and the grinding of paints, enamels and the like which consists of an outer tubular stator and an inner rotor revolvable in the stator. Forks are provided on the outer wall of the rotor for supporting rollers for rotation while permitting the rollers to be urged outwardly when the rotor turns so that the rollers ride on the inner surface of the stator. The rollers as thus supported are arranged in a spiral path along the outer wall of the rotor. The rollers are formed with separate grooves which define spiral ribs running from end to end of the rollers. The corners of the ribs are sharp and are maintained sharp by riding on the inner surface of the stator.

5 Claims, 4 Drawing Figures ROLLER OR BALL MILL FOR THE REFINING OF COCOA AND CHOCOLATE AND THE GRINDING OF PAINTS, ENAMELS AND THE LIKE CROSS REFERENCE TO RELATED APPLICATION This application is an improvement over copending application Ser. No. 81072 filed Oct. 15, 1970 by Claudio Consoli for Ball or Roller Mill for the Refining of Cocoa, Chocolate, and the Grinding of Paints, Lacquers, Enamels and the Like, now US. Pat. No. 3,709,442 granted Jan. 9, 1973.

BACKGROUND OF THE INVENTION 1. Field of the Invention Roller mill for refining and grinding.

2. Description of the Prior Art A ball or roller mill is described and shown in the above patent, which consists of an inner rotor, and of an ,outer tubular stator, between which confronting surfaces, e.g., spirally extending channels are provided for the accommodation of balls or rollers, which are thereby guided across a well defined path. The material to be comrninuted ,is forced along such spiral path, whereby successful results can be obtained, owing to rolling action of rollers or balls, conveyed by the rotor and urged into contact with the stator inner wall.

The thus designed machine has proved to be highly efficient and adequate in its performance, since the grinding fineness or final particle size. can be controlled not only by varying the processing time of material in the mill (i.e., acting on the pump by which same material is fed), but also be adjusting the RPM of the rotor.

As regard to the ball embodiment form of such mill, the same has been proved particularly suitable 'for harder products (owing to small grinding surfaces) and at any rate hardly capable of being further improved, in view of the shape of the grinding bodies.

As to the embodiment of such form wherein rollers are provided as grinding bodies, it is to be remembered that rollers having a smooth rolling surface are foreseen for the use in the said Patent.

Now, many experimental tests, performed in particular on rather soft materials, as, e.g., chocolate, with which the use of rollers, instead of balls, is more suitable, owing to larger contact surface between grinding bodies and product, and thus due to lower specific pressure, have made manifest that the best milling effect takes place around the corners, i.e., adjacent to front sides of rollers, and that the sharper the corners are, the more efficient is the action of rollers.

SUMMARY OF THE INVENTION 1. Purposes of the Invention It is an object of the invention to provide a mill of the character described employing rollers of such configuration that a better milling effect is obtained on soft materials such, for instance, as chocolate. I

It is another object of the invention to provide a mill of the character described in which the rollers are provided with spiral grooves between which spiral ribs are defined that extend from end to end of the rollers.

It is another object of the invention to provide a mill of the character described in which the corners of the ribs are sharp and ride on the inner surface of the stator, the rollers being so mounted as to permit radially outward movement into contact with said surface so that the corners of the ribs are self-sharpening.

2. Brief Description of the Invention The mill of the present invention constitutes an outer tubular stator within which an inner rotor turns. The outer surface of the inner rotor supports a plurality of cradle bearings, i.e., forks, having open ends facing the stator. These forks are mutually arranged so as to define a spiral on the rotor. The forks are provided in pairs, the forks of each pair being registered parallel to the axis of rotation of the rotor. Each pair of forks rotatably receives journals at the opposite ends of a different roller so that the rollers like the pairs of forks are located in a spiral path extending along the rotor. Becuase the cradles have open end facings in the stator, the rollers are impelled outwardly as the rotor turns so that they ride on the inner surface of the stator. Individual rollers are provided with a spiral groove which defines a spiral rib. The corners of the ribs are sharp. Because the rollers ride on the inner surface of the stator as the rollers turn, as the rollers wear down the ribs are selfsharpened. The grooves may be either rectangular or trapezoidal in their form.

The invention now will be disclosed in the following description of two embodiments thereof.

In the accompanying drawings in which are shown various possible embodiments of the invention:

FIG. 1 is a front view of a few rollers;

FIG. 2 is a view taken on the line IllI of FIG. 1;

FIG. 3 is a cross-section of rollers, taken perpendicular to the rotation axis of the rotor and of the rollers;

and

FIG. 4 is an enlarged fragmentary sectional view of the roller and associated portion of the stator illustrat ing a modified form of the invention.

Referring now to the drawings, it is to be pointed out, first of all, that the parts and components similar or equivalent to those of said patent are denoted by the same reference numerals, while the components modified according to this patent are indicated by other reference numerals.

Thus, restricting the description to modified components only, denotes the rollers formed according to the present invention and guided between the supporting and guiding means, extending from the outer wall of rotor 4, which rotor turns in a stator S, and by which the spiral paths of the rollers and of material being ground are defined. Such rollers are formed with spirally extending grooves 15, having a rectangular crosssection, and providing two sharp corners 15a. A plurality of such sharp comers is therefore present on the surface at each edge of the ribs defined by the grooves.

Alternatively, the grooves may have a trapezoid shaped cross-section as shown in FIG. 4, with an angle of inclination adjusted according to hardness of materials to be comminuted.

As previously stated, the grinding efficiency is materially increased, and is uniformly maintained on the same high level unitl the threads are worn out.

Similarly to said patent, each roller is supported through their hubs 6a by forks 5, formed with suitable seats 5a, and from which it can be removed, when worn out, and replaced with a new roller. The forks permit the spirally ribbed rollers to shift radially outwardly into contact with the inner surface of the outer tubular .stator as the rollers turn so that the ribs of the rollers ride on said surface of the stator whereby to provide a self-sharpening action for the corners of the ribs.

Besides, the mode of operation of mill is wholly similar to that already described in the said patent, whereby a description thereof may be dispensed with, as it has been made for the components which are not significant for a good understanding of the present innovation.

Finally, it is to be added that, owing to higher grinding capacity of rollers designed as previously stated, the mill can be installed not only in a vertical position, but in any other position that might appear more convenient, and in particular in a horizontal position, wherein no changes occur in its operation, also due to the fact that recourse may be made to a forced feeding of material, whereby it can be abstained from the force of gravity.

1 claim:

1. A roller mill for the refining of cocoa and chocolate and for the grinding of paints, varnishes, enamels, and the like, said mill comprising an outer tubular stator, a tubular rotor turning inside of said stator, a plurality of bearing means on the external surface of the rotor, said bearing means defining a spiral path extending along the outer wall of the rotor, a plurality of rollers each associated with a different bearing means, said rollers having circumferential grooves, said grooves defining ribs with a smooth exterior surface the corners of the ribs being sharp, said bearing means being constructed to permit the rollers to shift radially outwardly when the roller turns into engagement with the inner surface of the stator so that the ribs of the rollers ride on said surface of the stator whereby to provide a selfsharpening action for said corners of the ribs as the ribs wear down.

2. A mill according to claim 1, wherein the grooves extend spirally of the rollers.

3. A mill according to claim 2 wherein the grooves extend spirally from end to end of the rollers.

4. A mill according to claim 1, wherein the grooves have a rectangular cross-section.

5. A mill according to claim 1, wherein the grooves show a trapezoidal cross-section.

Claims

1. A roller mill for the refining of cocoa and chocolate and for the grinding of paints, varnishes, enamels, and the like, said mill comprising an outer tubular stator, a tubular rotor turning inside of said stator, a plurality of bearing means on the external surface of the rotor, said bearing means defining a spiral path extending along the outer wall of the rotor, a plurality of rollers each associated with a different bearing means, said rollers having circumferential grooves, said grooves defining ribs with a smooth exterior surface, the corners of the ribs being sharp, said bearing means being constructed to permit the rollers to shift radially outwardly when the roller turns into engagement with the inner surface of the stator so that the ribs of the rollers ride on said surface of the stator whereby to provide a self-sharpening action for said corners of the ribs as the ribs wear down.