# US 5,346,146 A · Vertical pulverizer

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 5,346,146 A
- Document ID: US5346146A
- Status: Granted
- Kind: A
- Application number: 08/038,265
- Filed: 1993-03-29
- Granted: 1994-09-13
- Earliest claimed: 1992-03-30
- Assignees: Kubota Corporation
- Inventors: Sachihito Nitta
- Web page: https://patentgrep.com/patent/US5346146A

## CPC

- B02C 17/16: Mills in which a fixed container houses stirring means tumbling the charge
- B02C 17/163: {Stirring means}
- B02C: CRUSHING, PULVERISING, OR DISINTEGRATING IN GENERAL; MILLING GRAIN ({household tools and machines for pulverising foodstuffs, e.g. coffee and spice mills A47J42/00; pharmaceutical mortars A61J3/02; mechanical processing of refuse and garbage B03B9/06; dressing mould materials by grinding B22C5/04}; obtaining metallic powder by crushing, grinding or milling B22F9/04; {recovery of plastics by disintegrating B29B17/00; crushing raw materials in starch making C08B30/02; beaters for papermaking D21D1/02; crushing devices specially for transport in mines E21F13/002; slag crushing devices F23J1/00; fuel milling devices in combustion apparatus F23K1/00; household devices for crushing coal F24B15/02; ice disintegrating devices F25C5/02})

## Abstract

A vertical medium-stirring type pulverizer has a wear-preventive structure for preventing wear of its screw blade. The structure includes a plurality of magnets provided on the top surface of the screw blade. At least one of the pulverizing medium and the material to he pulverized which are contained in the pulverizing shell of the pulverizer is a magnetic material. The magnets serve to attract the magnetic medium or material thereto to form a lining on the top surface of the screw blade. A similar wear-preventive structure may be provided on the inner surface of the shell to prevent wear of the inner surface of the shell.

## Claims

### Claim 1

A vertical medium-stirring pulverizer comprising: a vertically extending pulverizing shell having an inner surface; pulverizing medium filling part of said shell, the inner surface of said shell being exposed to said pulverizing medium; a screw including a shaft extending vertically in said shell, and a blade extending along said shaft, said blade having an uppermost surface located radially outwardly of the shaft of said screw and exposed to the interior of said shell and to said pulverizing medium occupying part of the interior of said shell; a plurality of magnets disposed on at least one of said inner surface of said shell and said uppermost surface of said blade, each of said magnets having an uppermost portion facing away from the surface on which it is mounted exposed at said surface to the interior of said shell and to said pulverizing medium.

### Claim 2 (depends on 1)

A vertical medium-stirring pulverizer as claimed in claim 1, and further comprising a plurality of ribs disposed on said uppermost surface of said blade and spaced apart from one another, and wherein said magnets are disposed on the uppermost surface of said blade at locations between said ribs.

### Claim 3 (depends on 1)

A vertical medium-stirring pulverizer as claimed in claim 1, and further comprising a plurality of spaced apart ribs extending vertically along the inner surface of said shell, and a plurality of spaced apart ledges extending horizontally along the inner surface of said shell, and wherein said magnets are disposed on the inner surface of said shell at locations between said ribs and said ledges.

### Claim 4

In an operational vertical medium-stirring pulverizer including a vertically extending pulverizing shell having an inner surface, pulverizing medium filling part of said shell, the inner surface of said shell being exposed to said pulverizing medium, a screw including a shaft extending vertically in said shell and a blade extending along said shaft, said blade having an uppermost surface located radially outwardly of the shaft of said screw and exposed to the interior of said shell and thus to said pulverizing medium occupying part of the interior of said shell, and wherein at least one the pulverizer is a magnetic material, the improvement comprising a plurality of magnets disposed on at least one of said inner surface of said shell and said uppermost surface of said blade, each of said magnets having an uppermost portion facing away from the surface on which it is mounted exposed at said surface to the interior of said shell and to said pulverizing medium, said magnets having magnetism sufficient to attract said magnetic material thereto and onto said at least one of the inner surface and said uppermost surface.

### Claim 5 (depends on 4)

In a vertical medium-stirring pulverizer as claimed in claim 4, the improvement further comprising a plurality of ribs disposed on said uppermost surface of said blade and spaced apart from one another, and said magnets being disposed on the uppermost surface of said blade at locations between said ribs.

### Claim 6 (depends on 4)

In a vertical medium-stirring pulverizer as claimed in claim 4, the improvement further comprising a plurality of spaced apart ribs extending vertically along the inner surface of said shell, and a plurality of spaced apart ledges extending horizontally along the inner surface of said shell, and said magnets being disposed on the inner surface of said shell at locations between said ribs and said ledges.