US3764079A - Roller or ball mill for the refining of cocoa and chocolate and the grinding of paints, enamels and the like - Google Patents
Roller or ball mill for the refining of cocoa and chocolate and the grinding of paints, enamels and the like Download PDFInfo
- Publication number
- US3764079A US3764079A US00193648A US3764079DA US3764079A US 3764079 A US3764079 A US 3764079A US 00193648 A US00193648 A US 00193648A US 3764079D A US3764079D A US 3764079DA US 3764079 A US3764079 A US 3764079A
- Authority
- US
- United States
- Prior art keywords
- rollers
- stator
- ribs
- rotor
- grooves
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B02—CRUSHING, PULVERISING, OR DISINTEGRATING; PREPARATORY TREATMENT OF GRAIN FOR MILLING
- B02C—CRUSHING, PULVERISING, OR DISINTEGRATING IN GENERAL; MILLING GRAIN
- B02C15/00—Disintegrating by milling members in the form of rollers or balls co-operating with rings or discs
- B02C15/08—Mills with balls or rollers centrifugally forced against the inner surface of a ring, the balls or rollers of which are driven by a centrally arranged member
Definitions
- 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.
- 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.
- 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.
- 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.
- the rollers 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.
- 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;
- 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.
- rollers formed according to the present invention 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.
- 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.
- the grinding efficiency is materially increased, and is uniformly maintained on the same high level unitl the threads are worn out.
- 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.
- 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.
- 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.
- a mill according to claim 1 wherein the grooves show a trapezoidal cross-section.
Landscapes
- Engineering & Computer Science (AREA)
- Food Science & Technology (AREA)
- Crushing And Grinding (AREA)
- Confectionery (AREA)
- Disintegrating Or Milling (AREA)
- Crushing And Pulverization Processes (AREA)
- Mixers With Rotating Receptacles And Mixers With Vibration Mechanisms (AREA)
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 (5)
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.
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.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
IT26878/71A IT968032B (en) | 1971-07-10 | 1971-07-10 | BALL MILL OR ROLLS FOR THE RAF FINATION OF COCOA CHOCOLATE PAINTS PAINT ENAMELS AND MILAR PRODUCTS |
Publications (1)
Publication Number | Publication Date |
---|---|
US3764079A true US3764079A (en) | 1973-10-09 |
Family
ID=11220430
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US00193648A Expired - Lifetime US3764079A (en) | 1971-07-10 | 1971-10-29 | Roller or ball mill for the refining of cocoa and chocolate and the grinding of paints, enamels and the like |
Country Status (15)
Country | Link |
---|---|
US (1) | US3764079A (en) |
JP (1) | JPS5614343B1 (en) |
AT (1) | AT325399B (en) |
AU (1) | AU3785272A (en) |
BE (1) | BE775512A (en) |
BR (1) | BR7108003D0 (en) |
CA (1) | CA934348A (en) |
DE (1) | DE2152218A1 (en) |
DK (1) | DK147615C (en) |
ES (1) | ES396321A2 (en) |
FR (1) | FR2145899A6 (en) |
GB (1) | GB1368334A (en) |
IT (1) | IT968032B (en) |
NL (1) | NL7116073A (en) |
SU (1) | SU464089A3 (en) |
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4063687A (en) * | 1975-09-18 | 1977-12-20 | General Comminution Inc. | Comminution device |
EP0029734A1 (en) * | 1979-11-26 | 1981-06-03 | General Comminution Inc. | Multiple stage comminution device |
US6238724B1 (en) * | 1998-10-29 | 2001-05-29 | Kraft Foods, Inc. | Chocolate refining process |
US20100196574A1 (en) * | 2007-07-21 | 2010-08-05 | Luc Joseph Paul Antonie Marie Rumbaut | Process and product |
US20100203221A1 (en) * | 2007-07-21 | 2010-08-12 | Luc Joseph Paul Antonie Marie Rumbaut | Process |
CN110882811A (en) * | 2019-12-12 | 2020-03-17 | 江苏吉能达环境能源科技有限公司 | Multistage grinding superfine powder production facility |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE3503817C1 (en) * | 1985-02-05 | 1986-10-09 | DET-Dräger-Energie-Technik GmbH & Co KG, 4175 Wachtendonk | Device for crushing and / or mixing solid, pasty and / or liquid substances |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1269424A (en) * | 1917-07-19 | 1918-06-11 | Sebastiano Grassi | Mill. |
US1736394A (en) * | 1929-04-15 | 1929-11-19 | Arthur H Dierker | Grinding machine |
US2413793A (en) * | 1944-02-28 | 1947-01-07 | Renwick J Sharp | Vertical axis type mixing and chasing mill |
US2536332A (en) * | 1939-02-16 | 1951-01-02 | Vincent Henri Leon Xavier | Apparatus for refining fibrous materials |
-
1971
- 1971-07-10 IT IT26878/71A patent/IT968032B/en active
- 1971-10-20 DE DE19712152218 patent/DE2152218A1/en active Pending
- 1971-10-21 GB GB4901471A patent/GB1368334A/en not_active Expired
- 1971-10-23 ES ES396321A patent/ES396321A2/en not_active Expired
- 1971-10-26 FR FR7138465A patent/FR2145899A6/fr not_active Expired
- 1971-10-28 AT AT930371A patent/AT325399B/en not_active IP Right Cessation
- 1971-10-29 US US00193648A patent/US3764079A/en not_active Expired - Lifetime
- 1971-11-18 BE BE775512A patent/BE775512A/en not_active IP Right Cessation
- 1971-11-19 SU SU1715166A patent/SU464089A3/en active
- 1971-11-23 NL NL7116073A patent/NL7116073A/xx unknown
- 1971-11-24 CA CA128490A patent/CA934348A/en not_active Expired
- 1971-12-02 BR BR8003/71A patent/BR7108003D0/en unknown
- 1971-12-03 DK DK592671A patent/DK147615C/en not_active IP Right Cessation
-
1972
- 1972-01-12 AU AU37852/72A patent/AU3785272A/en not_active Expired
- 1972-05-18 JP JP4862972A patent/JPS5614343B1/ja active Pending
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1269424A (en) * | 1917-07-19 | 1918-06-11 | Sebastiano Grassi | Mill. |
US1736394A (en) * | 1929-04-15 | 1929-11-19 | Arthur H Dierker | Grinding machine |
US2536332A (en) * | 1939-02-16 | 1951-01-02 | Vincent Henri Leon Xavier | Apparatus for refining fibrous materials |
US2413793A (en) * | 1944-02-28 | 1947-01-07 | Renwick J Sharp | Vertical axis type mixing and chasing mill |
Cited By (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4063687A (en) * | 1975-09-18 | 1977-12-20 | General Comminution Inc. | Comminution device |
EP0029734A1 (en) * | 1979-11-26 | 1981-06-03 | General Comminution Inc. | Multiple stage comminution device |
US6238724B1 (en) * | 1998-10-29 | 2001-05-29 | Kraft Foods, Inc. | Chocolate refining process |
US20100196574A1 (en) * | 2007-07-21 | 2010-08-05 | Luc Joseph Paul Antonie Marie Rumbaut | Process and product |
US20100203221A1 (en) * | 2007-07-21 | 2010-08-12 | Luc Joseph Paul Antonie Marie Rumbaut | Process |
US8298605B2 (en) | 2007-07-21 | 2012-10-30 | Barry Callebaut Ag | Process for producing chocolate |
US8329242B2 (en) | 2007-07-21 | 2012-12-11 | Barry Callebaut Ag | Process for making chocolate |
CN110882811A (en) * | 2019-12-12 | 2020-03-17 | 江苏吉能达环境能源科技有限公司 | Multistage grinding superfine powder production facility |
CN110882811B (en) * | 2019-12-12 | 2021-04-30 | 江苏吉能达环境能源科技有限公司 | Multistage grinding superfine powder production facility |
Also Published As
Publication number | Publication date |
---|---|
AU3785272A (en) | 1973-07-19 |
NL7116073A (en) | 1973-01-12 |
ES396321A2 (en) | 1974-05-01 |
DK147615B (en) | 1984-10-22 |
DE2152218A1 (en) | 1973-02-01 |
DK147615C (en) | 1985-04-29 |
BR7108003D0 (en) | 1973-04-10 |
IT968032B (en) | 1974-03-20 |
SU464089A3 (en) | 1975-03-15 |
BE775512A (en) | 1972-03-16 |
CA934348A (en) | 1973-09-25 |
FR2145899A6 (en) | 1973-02-23 |
JPS5614343B1 (en) | 1981-04-03 |
AT325399B (en) | 1975-10-27 |
GB1368334A (en) | 1974-09-25 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US3764079A (en) | Roller or ball mill for the refining of cocoa and chocolate and the grinding of paints, enamels and the like | |
CN108187862A (en) | A kind of rapidly and efficiently sand making machine | |
US1431475A (en) | Means for crushing and grinding ore and rock | |
US1711464A (en) | Grinding machine | |
US1814587A (en) | Pulp refining apparatus | |
US3138337A (en) | Pulverizing bowl mill utlizing a segmented bull ring | |
US3739993A (en) | Grinding mills | |
US2093703A (en) | Pulverizing apparatus | |
US2558327A (en) | Grinding ball for ball mills | |
US3124314A (en) | Klein | |
US3905559A (en) | Armoured ring for deflecting a dust-gas flow, in roller grinding mills | |
US2898053A (en) | Impact crushing machine | |
CN206046105U (en) | Emery stick mill | |
US1185046A (en) | Reduction-mill. | |
US2757872A (en) | Crushing mill | |
US2510970A (en) | Radial disk mill with cooperating ribbed plates | |
US2730307A (en) | Plural stage rotary drum pulverizers, with grinding plates of regular polygonal shape | |
US3539115A (en) | Pump and ball mill | |
US1363990A (en) | Ore-grinding machine | |
JPS58101744A (en) | Shaft type crusher | |
US1692974A (en) | Balanced ball mill | |
US245313A (en) | John s | |
US1380112A (en) | Grinding-machine | |
CN209222264U (en) | A kind of ball mill being moved easily | |
US3344998A (en) | Pulverizer |