USING A SIZE REDUCTION MACHINE

Field of Invention

This invention relates to a screen module for preparing cosmetics using

a size reduction machine. In particular, this invention relates to a screen module having

a fine screen nested and secured against a rigid support screen.

Background of the Invention

Size reduction machines utilise a frusto-conical shaped screen located

in a channel between an input and an output. Such size reduction machines are more

particularly described in United States Patent No. 4,759,507 and 5,330,113. In these

machines, various screens and impellers are used depending on the size and type of

product that is being processed. The screens have apertures in different sizes and shapes to produce a desired milled product.

The production of cosmetics presents particular problems. The

particulate size of cosmetics is required to be very fine. As a result fine screens with

fine mesh sizes are needed. These screens are delicate and are often damaged during

use and during cleaning, requiring frequent replacement.

A secondary screen has been used as support for the primary fine screen

in addressing the problem of breakage during use. However, the primary screen is still

able to be separated from the secondary screen. Since cosmetics production requires

frequent cleaning, the fine screens are routinely damaged once the fine screen has

become separated from the secondary screen during cleaning.

Summary of the Invention

The disadvantages of the prior art may be overcome by providing screen

module for a size reduction machine where the module has a fine screen nested with

and secured against a support screen for producing fines for cosmetics production.

It is desirable to provide a screen module which can be cleaned and

sanitized as a unit minimizing a risk of damage to a fine screen nested within a rigid

support screen.

It is still further desirable to provide screen module which can be used

in a underdriven size reduction machine.

It is still fiirther desirable to provide screen module which can be used

in a top driven size reduction machine.

According to one aspect of the invention, there is provided a screen module for use in a size reduction machine. The module has a rigid screen having a

tapered apertured wall formed in a frusto-conical shape. The rigid screen has an open

wide end and a flat end. The wide end is mountable within a channel of the size

reduction machine at a predetermined distance from a complementarily shaped

impeller. The module has a fine screen nested within the rigid screen and against the

tapered apertured wall. The fine screen has a wide end and a narrow end

corresponding to the apertured wall. An adaptor disc is releasably secured within the

rigid screen at the flat end. The adaptor has a tapered outer perimeter for seating against the tapered apertured wall when the adaptor disc is secured within the rigid

screen, clamping the narrow end of the fine screen therebetween. A clamp ring is releasably secured at the open wide end of the rigid screen. The clamp ring has a

tapered inner perimeter for seating against the tapered apertured wall when secured

against the open wide end, clamping the wide end of the fine screen therebetween.

According to another aspect of the invention, there is provided a screen

module having an axial bore for receiving a spindle of an underdriven size reduction

machine.

According to another aspect of the invention, there is provided a screen

module having a closed bottom, and a spindle is drivingly rotated from above the

screen module.

Detailed Description of the Drawings In figures which illustrate embodiments of the invention,

Figure 1 is a side sectional view of a size reduction machine incorporating a screen module of the present invention;

Figure 2 is a side sectional view of the screen module of the present invention;

Figure 3 is an exploded perspective view of the screen module of

Figure 2;

Figure 4 is an exploded sectional view of the size reduction

machine of Figure 1;

Figure 5 is an exploded view of a second embodiment of a screen

module of the present invention;

Figure 6 is a side sectional view of a size reduction machine incorporating the screen module of Figure 5.

Detailed Description of the Invention

The size reduction machine incorporating the screen module 10 of the

present invention is illustrated in Figure 1. The size reduction machine generally has

a shroud 12, an underdrive gear box 14 and an impeller 16.

Referring to Figures 1 and 2, the underdrive gear box 14 and impeller

16 are axially located within the shroud 12 having an input 18 and an output 20.

Impeller 16 is mounted on spindle 22 in a manner well known in the art. United States

Patent no. 5,330,113 describes an underdriven size reduction machine and a method

of mounting the impeller on a spindle and drivingly rotating same. The contents of

United States Patent no. 5,330,113 are incorporated herein by reference.

Screen module 10 comprises a rigid screen 24 which has a tapered apertured wall 26 formed in a frusto-conical shape with a wide end 28 and a flat narrow end 30. End 28 is open while end 30 is fully or substantially closed. The rigid screen 24 has a circular flange 32 which surrounds and extends outwardly of the wide

end 28. Flange 32 has a recessed lip 34 extending about an inner periphery of the end

28. Spaced about the outer periphery are threaded bores 36 which receive lifting rods

38 which releasably retain screen module 10 onto shroud 12.

Screen module 10 further includes a disc adaptor 40 which is sized to

fit within the base of flat end 30. The disc adaptor 40 has a tapered outer periphery

42 which is complementarily shaped to seat against the tapered apertured wall 26 when

the adaptor disc 40 is secured within the rigid screen 24.

Screen module 10 also includes a clamp ring 44 which is sized to fit

within lip 34. Clamp ring 44 has a tapered inner periphery 46 which is

complementarily shaped to seat against the open end 28 of tapered apertured wall 26

when the clamp ring is secured to the rigid screen 24.

Spaced about flange 32 are a plurality of threaded apertures 47 for

receiving holding screws 48 which releasably retain clamp ring 44 onto rigid screen 24.

Screen module 10 finally includes a fine screen 50. The fine screen 50

has an open wide end and an open narrow end. The open wide end has a flange 51

extending thereabout. Fine screen 50 is sized and complementarily shaped to nest

within the rigid screen 24 to seat against the tapered apertured wall 26. The openings

of fine screen 50 will normally be in the range of 0.005" or 100 U.S. standard mesh

size, which is greater than the openings of tapered apertured wall 26. Fine screen 50 will generally have a thickness of 0.005" or less. Fine screen 50 is preferably stainless steel.

Adaptor disc 40 has an axially extending tubular section 52 having an

external thread 54 and an axial bore 56. Axial bore has a counterbore 58 for receiving

a fastening tool used to rotate and lock the adaptor disc 40 to the rigid screen 24. Rigid screen 24 has an external boss 60 which has an axial counterbore 62 having an

internal thread and an opening 64. The internal thread is complementary with the

external thread 54. The diameter of the axial bore 56 and opening 64 are substantially

equal and sized to receive in a sliding fit spindle 22 of gear box 14.

Referring to Figure 3, the screen module 10 of the present invention is assembled by inserting the fine screen 50 to nest within the rigid screen 24 until the

narrow open end sits about the periphery of the flat end 30 of the rigid screen 24.

Adaptor disc 40 engages the rigid screen 24 by threading tubular section 52 into

counterbore 58. The adaptor disc 40 is tightened firmly clamping fine screen 50 into

the rigid screen 24. Clamp ring 44 is then applied to the wide open end 28. Holding

screws 48 are then applied to retain clamp ring 44 thereon clamping the wide end of

fine screen 50 to the rigid screen 24.

The screen module 10 of the present invention is now assembled. The

module 10 may be handled with minimum risk of damage to the fine screen 50. The

screen module may be cleaned as a unit to be sanitize. Since the fine screen 50 is not

removed for cleaning purposes, there is less possibility that the operator will damage

the fine screen 50.

Once assembled, the screen module is installed by sliding the screen

module 10 over the spindle 22 of the gear box 14. Flange 32 will rest on a lip 68 of

shroud 12. Lifting rods 38 are inserted through bores 66 into threaded bores 36 securing screen module 10 on the shroud 12. The impeller 16 is then installed onto spindle 22 and spaced a predetermined distance from the screen defining a gap.

Procedures and apparatus for setting the gap are well known and more particularly

described in United States patent no. 5,282,579, the contents of which are hereby

incorporated by reference. Bolt 70 with washer 72 threadingly engage threaded bore 74 of spindle 22 to retain impeller 16 thereon. Cosmetics production requires a relatively high angular speed of

impeller relative to the fine screen. Accordingly, a wide shallow frusto-conical shape

for rigid screen 24 is preferred.

In use, the screen module 10 may be installed and removed repeatedly

without the operator manipulating the fine screen 50. The screen module 10 may be

washed and sanitized as a unit minimizing the handling and risk of damage to the fine

screen 50.

As the impeller 16 rotates, centrifugal forces will urge particulate

material to be directed outwardly to and through the fine screen 50. The particulate

material will then pass through the apertures of apertured wall 26. The size of

apertures of apertured wall 26 is greater than the mesh size of fine screen 50 and

therefore rigid screen does not affect the processing of the particulate.

Referring to Figures 5 and 6, a second embodiment ofthe screen module

of the present invention is illustrated. The screen module 110 is identical to screen

module 10 except that rigid screen 124 is closed and does not include opening 64.

Screen module 110 is intended to be used with a top driven size reduction machine as

described in United States patent nos. 4,759,507, 4,768,722 and 4,773,599, the

contents of which are hereby incorporated by reference. In this case, the impeller 116

is connected to a downwardly extending spindle 122.

While the invention herein has been described in connection with

exemplary embodiments, it will be understood that many modifications will be apparent

to those skilled in the art.