CONE MILLS

Abstract

A cone mill comprises a rotating tool for moving friable material across a static conical screen. The tool is driven to rotate by a tool drive shaft. The mill includes a motor, the motor causing rotation of a motor drive shaft. The tool drive shaft and the motor drive shaft are located an angle with respect to each other and the mill comprises a universal joint for transferring rotary motion from the motor through the angle to the tool.

Claims

1. A cone mill comprising a rotating tool for moving friable material across a static conical screen, the tool being driven to rotate by a tool drive shaft, the mill includes a motor, the motor causing rotation of a motor drive shaft, the tool drive shaft and the motor drive shaft being located an angle with respect to each other, the mill comprising a universal joint for transferring rotary motion from the motor through the angle to the tool.

2. A cone mill as claimed in claim 1, in which the universal joint is a double universal joint.

3. A cone mill as claimed in claim 1, in which the universal joint is a double Cardan joint.

4. A cone mill as claimed in claim 1, in which the angle is in the range 90 to 125.

5. A cone mill as claimed in claim 4, in which the angle is approximately 90.

6. A cone mill as claimed in claim 5, in which the universal joint comprises two Cardan-style universal joints each joint providing approximately 45 of rotary angle.

7. A cone mill as claimed in claim 1, in which the rotating tool is vertically mounted.

8. A cone mill as claimed in claim 1, in which, in use, the tool drive shaft is generally vertical and the motor drive shaft is generally horizontal.

9. A cone mill as claimed in claim 1, in which the tool is a beater.

10. A cone mill as claimed in claim 1, in which the cone diameter is approximately: 680 mm, 540 mm, 340 mm, 220 mm, 170 mm, 120 mm or 75 mm.

11. A pharmaceutical powder milling machine comprising a cone mill as claimed in claim 1.

12. A cone mill drive shaft coupling comprising a universal joint for transferring rotary motion from a motor through an angle to a milling tool.

13. A cone mill drive shaft comprising two rotatable shaft sections, the sections being positioned at an angle with respect to each other, the shaft comprising a coupling for transferring rotary motion through the angle in use, the coupling comprising a universal joint.

14. A cone mill comprising a rotating tool for moving friable material across a static conical screen, the tool being driven to rotate by a tool drive shaft, the mill includes a motor, the motor causing rotation of a motor drive shaft, the tool drive shaft and the motor drive shaft being located at an approximately 90 degree angle with respect to each other, the mill comprising a gearless joint for transferring rotary motion from the motor through the angle to the tool, said gearless joint comprising a double universal joint having a first joint and a second joint, each of said joints providing approximately 45 degrees of rotary angle of said 90 degrees between said motor drive shaft and said tool drive shaft.

15. A cone mill as claimed in claim 14, in which the first and second joints are Cardan-style universal joints.

16. A cone mill as claimed in claim 14, in which the first and second joints are mounted back-to-back with a center yoke, said first joint being connected, directly or indirectly, to said motor drive shaft, said second joint being connected, directly or indirectly, to said tool drive shaft.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The present invention will now be more particularly described, by way of example, with reference to the accompanying drawings, in which:

[0023] FIG. 1a shows a side view of a cone mill formed in accordance with the present invention;

[0024] FIG. 1b shows a top view of a cone mill formed in accordance with the present invention;

[0025] FIG. 1c shows a bottom view of a cone mill formed in accordance with the present invention;

[0026] FIG. 1d shows a front view of a cone mill formed in accordance with the present invention;

[0027] FIG. 2 is a section of FIG. 1a;

[0028] FIG. 3 is an exploded view of the mill of FIGS. 1 and 2;

[0029] FIG. 4 is a magnified exploded view of the conical screen and beater assembly forming part of the mill of FIGS. 1 to 3;

[0030] FIG. 5 is a magnified exploded view of a beater shaft assembly;

[0031] FIG. 6 is a magnified exploded view of part of a milling chamber and a drive shaft assembly;

[0032] FIG. 7 is an exploded view of a motor housing and motor stool;

[0033] FIG. 8a illustrates the structure and functioning of a joint which couples the drive and tool shafts of the mill;

[0034] FIG. 8b illustrates the structure and functioning of a joint which couples the drive and tool shafts of the mill; and

[0035] FIG. 9 is a parts list which also relates to reference numerals used in FIGS. 1 to 8b.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0036] The example embodiments are described in sufficient detail to enable those of ordinary skill in the art to embody and implement the systems and processes herein described. It is important to understand that embodiments can be provided in many alternative forms and should not be construed as limited to the examples set forth herein.

[0037] Accordingly, while embodiments can be modified in various ways and take on various alternative forms, specific embodiments thereof are shown in the drawings and described in detail below as examples. There is no intent to limit to the particular forms disclosed. On the contrary, all modifications, equivalents, and alternatives falling within the scope of the appended claims should be included. Elements of the example embodiments are consistently denoted by the same reference numerals throughout the drawings and detailed description where appropriate.

[0038] Unless otherwise defined, all terms (including technical and scientific terms) used herein are to be interpreted as is customary in the art. It will be further understood that terms in common usage should also be interpreted as is customary in the relevant art and not in an idealized or overly formal sense unless expressly so defined herein.

[0039] In the following description, all orientational terms, such as upper, lower, vertical, horizontal, radially and axially, are used in relation to the drawings and should not be interpreted as limiting on the invention.

[0040] Referring first to FIGS. 1a-d and 2 there is shown a cone mill generally indicated 50.

[0041] In brief, the mill 50 comprises a milling chamber 29 and a motor 15 which are orientated at approximately 90 degrees with respect to each other.

[0042] The motor 15 drives a drive shaft 31.15, which in this embodiment is orientated to rotate along a generally horizontal axis. The milling chamber 29 includes a beater 23 which is rotatable within a conical screen 26 and is driven to do so in use by a tool drive shaft 32.13 which is orientated to rotate along a generally vertical axis. It will therefore be seen that rotational drive provided by the motor must be transferred from the shaft 31.15 to the shaft 32.13 through a right angle. In this embodiment, if the motor shaft 31.15 is rotated anti-clockwise (looking toward the mill) then the beater 23 will rotate clockwise.

[0043] The transfer the rotary motion the drive shafts 31.15, 32.13 are coupled by a double universal joint 36. The universal joints are capable of transmitting torque and rotational motion from one shaft to another when their axes are inclined to each other by some angle.

[0044] The replacement of gears with a universal joint means that lubrication on the gears is removed. All lubrication in the bearing is now contained in those components by seals, hence removing a major contamination source.

[0045] FIGS. 8a and 8b illustrate the structure and functioning of the joint 36.

[0046] The double Cardan style joint 36 consists of two universal joints 55, 60 mounted back to back with a center yoke 65.

[0047] The joint 36 effectively comprises two halves; each half having two degrees of freedom and providing 45 degrees of movement.

[0048] FIG. 8a is the starting point at which rotation is applied at the right-hand side. FIG. 8b is the joint rotated through approximately 45 degrees.

[0049] In use product is fed from above the chamber into the conical screen. Rotation of the beater causes product to be moved across the screen by the beater arms. The action of the beater breaks product down into smaller particles until it can fall through the screen. The material falls through the chamber 29 and out of the bottom.

[0050] Although illustrative embodiments of the invention have been disclosed in detail herein, with reference to the accompanying drawings, it is understood that the invention is not limited to the precise embodiments shown and that various changes and modifications can be effected therein by one skilled in the art without departing from the scope of the invention as defined by the appended claims and their equivalents.

[0051] Thus, the present invention is well adapted to carry out the objectives and attain the ends and advantages mentioned above as well as those inherent therein. While presently preferred embodiments have been described for purposes of this disclosure, numerous changes and modifications will be apparent to those of ordinary skill in the art. Such changes and modifications are encompassed within the spirit of this invention as defined by the claims.