GB2072529A - An improved grinding machine - Google Patents

Abstract

Baffler means (51, 52) are provided on the lid 5 of a mill to disturb the vortex flow generated in the grinding operation, thereby effecting sedimentation of the floating material carried by the vortex flow, increasing effective grinding action and enhancing efficiency. <IMAGE>

Description

SPECIFICATION An improved grinding machine The present invention relates to a grinding machine, particularly, a relatively small-size one which is usually employed in producing medicine powedr or in doing experimentary work in the chemistry laboratory.

One disadvantage of the conventional grinding machine is that the vortex flow generated in the grinding operation shall carry a certain amount of the material under grinding and make it float upwards, thereby lessening the frequency of its receiving the effective grinding action of the grinding machine's blade device.

In view of this disadvantage of the conventional grinding machines, the present invention provides a pair of appropriately-shaped baffler means protruding out of the lower surface of the grinding machine's lid to interfere the vortex flow generated in the grinding operation. The baffler means can effect a sedimentation of the floating material carried by the vortex flow and increase the frequency of the material-under-grinding's receiving effective grinding action. Consequently, the grinding efficiency can be enhanced.

Other objects and advantages of the invention will become apparent during the following discussion of the accompanying drawings, wherein: Figure la is a perspective view of a grinding machine without a lid in accordance with the present invention; Figure 1b is a perspective view of a lid which is fitted with the grinding machine shown in Fig. 1a; and Figure 2 is an exploded perspective view of another lid of the grinding machine.

Referring to Fig. la and ib, a grinding machine, according to the present invention, comprises a container 4, a plurality of blades 1 rotatably secured on a pivot 2 which is aligned with the longitudinal axis of the container 4 and a lid 5. In the grinding machine's operation, the lid 5 seals the container 4 and the blades 1 are activated to rotate by motor means. A pair of bafflers 51, 52 are provided at the under side of the lid 5. The bafflers 51, 52 are symmetrically positioned, relative to the center of the lid 5 and at appropriate distance from the lid center; i.e., at appropriate distance from the center of the vortex flow generated in the grinding operation. The shape of each baffler 51, 52 is parabolic.

Each baffler's surface which faces the direction of the vortex flow; i.e., the rotating direction of the blades 3, meets the lower surface of the lid 5 at a certain angle.

Referring to Fig. 2, a pair of bafflers 54, 55 are symmetrically positioned on a board 53, relative to the board center and at appropriate distance from the board center. The board 53 has the same area as the lid 5 and is adapted to be laminated to the lower surface of the lid 5.

Under the inventor's experimentation, the greatest efficiency of the above-described grinding machine is achieved when the baffler's surface which faces the direction of the vertex flow meets the rotating level of the blades 1 at an angle of 90 or an angle larger than 90". But, the bafflers creat additional motor load. By gradually increasing the quantity of material simultaneously put into the grinding machine to receive grinding action, it is found that the quantity of material permitted to be simultaneously put into the grinding machine to receive grinding action is smallest when the baffler's surface which faces the direction of the vortex flow meets the rotating level of the blades 1 at an angle of 90 or larger than 90 ; and, is largest if the lid 5 are not provided with bafflers.In conclusion, it is preferred that the baffler's surface which faces the direction of the vortex flow meets the rotating level of the blades 1 at approximately 45 or within a wider range of 30 to 60 .

One experiment instance is as follows: 1. the grinding machine: inner diameter of the container: 11 cm depth of the container: 4.5 cm length of the blades: 9 cm thickness of the blads: 2 mm motor power: 0.25 horse power 2. quantity of material simultaneously put into the grinding machine: 3.8 g.

3. observation frequency: 5 seconds.

In case of the lid of the above-described grinding machine not provided with baffler means in accordance with the present invention, the effect of a one-minute grinding operation proves to be almost the same as that of a three-minute grinding operation, that is, the refinement of the material having been grinded for one minute proves to be almost the same as the refinement of the material having been grinded for three minutes.

In case of the lid of the above-described grinding machine being provided with baffler means in accordance with the present invention, the refinement of the material having been grinded for fifteen seconds proves to be much better than that of the material having received a one-minute or a three-minute operation of the conventional grinding machines, the lid thereof not being provided with baffler means.

As many apparently widely different embodiments of this invention may be made without departing from the spirit and scope thereof, it is to be understood that the invention is not limited to the specific embodiments thereof except as defined in the appended claims.

CLAIMS 1. A grinding machine comprising a cylindrical body; a lid adapted to seal said body; a plurality of blades rotatable when activated by a driving motor and mounted on a transmission shaft within said body; at least one baffler means secured on the lower surface of said lid for interfering the vortex flow generated in the grinding operation and effecting a sedimentation of the floating material carried by said vortex flow, wherein at least a surface of said baffler means facing the direction of said vortex flow generated in the grinding operation meets the rotating level of said blads at an angle within the range of 30c to 60".

2. A grinding machine as claimed in Claim 1, wherein said baffler's surface which faces the direction of said vortex flow generated in the grinding operation meets said rotating level of said blades at a preferrable angle of 45.

CLAIMS (10 Apr 1981) 1. A grinding machine comprising a cylindrical hollow body member rotatable about a longitudinal centre axis, a lid member adapted to close said hollow body member in use, a grinding device rotatable in a radial plane within the hollow body member to produce a vortex flow path about said axis driving means to rotate said grinding device, and at least one baffle means secured on the inner surface of said lid so as to project within the hollow body member into said flow path at an inclined angle said angle being acute with respect to the plane of rotation of the grinding device.

2. A grinding machine as claimed in claim 1, wherein two baffle means are secured to the inner surface of the lid at diametrically opposed positions, equally spaced from said axis.

3. A grinding machine as claimed in either one of claims 1 and 2 wherein the baffle means have a curved surface.

4. A grinding machine constructed and arranged substantially as hereinbefore described with reference to (a) Figs. 1 a, and 1 b (b) Figs. 1 a, and 2 of the drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (4)

**WARNING** start of CLMS field may overlap end of DESC **. plurality of blades rotatable when activated by a driving motor and mounted on a transmission shaft within said body; at least one baffler means secured on the lower surface of said lid for interfering the vortex flow generated in the grinding operation and effecting a sedimentation of the floating material carried by said vortex flow, wherein at least a surface of said baffler means facing the direction of said vortex flow generated in the grinding operation meets the rotating level of said blads at an angle within the range of 30c to 60". 2. A grinding machine as claimed in Claim 1, wherein said baffler's surface which faces the direction of said vortex flow generated in the grinding operation meets said rotating level of said blades at a preferrable angle of 45. CLAIMS (10 Apr 1981)

1. A grinding machine comprising a cylindrical hollow body member rotatable about a longitudinal centre axis, a lid member adapted to close said hollow body member in use, a grinding device rotatable in a radial plane within the hollow body member to produce a vortex flow path about said axis driving means to rotate said grinding device, and at least one baffle means secured on the inner surface of said lid so as to project within the hollow body member into said flow path at an inclined angle said angle being acute with respect to the plane of rotation of the grinding device.

2. A grinding machine as claimed in claim 1, wherein two baffle means are secured to the inner surface of the lid at diametrically opposed positions, equally spaced from said axis.

3. A grinding machine as claimed in either one of claims 1 and 2 wherein the baffle means have a curved surface.

4. A grinding machine constructed and arranged substantially as hereinbefore described with reference to (a) Figs. 1 a, and 1 b (b) Figs. 1 a, and 2 of the drawings.