AU2003100251A4 - Programmable material sieve - Google Patents

Description

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION INNOVATION PATENT PROGRAMMABLE MATERIAL SIEVE The following statement is a full description of this invention, including the best method of performing it known to me: PROGRAMMABLE MATERIAL SIEVE There are numerous industrial processes which require the sorting of bulk material by size. For example when diamonds are mined it is necessary to separate the stones into various sizes which relate to carrot value. For small scale production this can be achieved manually by using a cylinder into which sieve plates with various hole diameters can be placed. The cylinder is then moved in a circular and shaking motion to move the stones over the holes resulting in the smaller stones falling through the holes where they are collected.

For larger scale production mechanically operated sieves are available which, by using a motorised cam, simply shake the product vertically over the sieve holes. Currently available motorised mechanical sieves are inherently extremely noisy, only provide one major movement (up and down) and, due to the high impact force, can damage the product. This invention uses three microprocessor controlled adjustable solenoid assemblies with integral position sensors spaced at 120 degrees, to achieve a variety of programmable circular and vertical movements of the product over the sieve holes, resulting in a faster sieving time with less damage at a significantly lower noise level. The invention is targeted at, but not limited to, the sieving of Diamonds, The invention may be better understood with reference to the illustrations of embodiments of the invention which: Figure I is a top elevation of a Programmable material sieve showing the relative location of the three solenoids to each other and to the sieve barrel Figure 2 is a sectioned front elevation of a Programmable material sieve showing the method of fixing and the relative position of the sieve barrel to the solenoids.

Figure 3 and 4 show the relationship between the position sensor and the solenoid plunger.

The sieve barrel 1 is a metal cylinder with a step 9 on which the sieve plate 8 rests. The sieve barrel 1 is connected to the solenoids 2, 3 and 4 using hard rubber spacers 5, 6 and 7. The distance 15 moved by the solenoids is selected using adjustors 10, 11 and 12. Position sensors 13 provide an electronic signal which can be related to the distance the solenoid plunger 14 has moved relative to the sensor 13. Figure 3 shows the solenoid plunger 14 position relative to the sensor 13 with no power to the solenoid, and Figure 4 shows the solenoid plunger 14 position relative to the sensor 13 with power applied to the solenoid. Each solenoid has a position sensor.

The sensor can be optical, magnetic or any device which can provide an electronic signal which can be related to the distance between the solenoid plunger 14 and the sensor 13.

Initially none of the solenoids are powered. If, for example, solenoid 3 is powered it will move vertically a distance 15, lifting the sieve barrel I and sieve plate 8, until the solenoid plunger 14 reaches the internal end stop of the solenoid where it will stop, However, due to the kinetic energy stored in the product the product will continue moving away from the sieve plate 8.

The sieve barrel is now raised a distance 15 pivoted about solenoids 4 and The signal from the position sensor 13 is used to switch off the power to the solenoid when the solenoid plunger has been physically stopped. The mass of the sieve barrel I and sieve plate 8 forces the solenoid plunger back to the none powered position and the product falls back onto the sieve plate 8 but at a position nearer to solenoids 2 and 4.

Repeated cycles of power on then power off moves the product away from solenoid 3 over the holes in the sieve plate 8 towards solenoids 2 and 4 resulting in the smaller samples of the product falling through the sieve holes for collection in container 16.

Microprocesor control By the use of a microprocessor system the sequence of operation of solenoids 2,3,4 can be programmed. This sequence can be refetrred to as a "Mode". There are at least five "Modes" of operation:- Mode 1, Solenoid 3 is switched on then off.

Solenoid 2 is switched on then off.

Solenoid 4 is switched on then off.

This results in a gentle clockwise movement of the product over the sieve plate 8.

Mode 2. Solenoid 4 is switched on then off.

Solenoid 2 is switched on then off.

Solenoid 3 is switched on then off.

This results in a gentle anti clockwise movement of the product over the sieve plate 8.

Mode 3 Solenoid 3 2 are switched on then off.

Solenoid 3 4 are switched on then off Solenoid 4 2 are switched on then off, This results in a more vigorous clockwise movement of the product over the sieve plate 8.

Mode 4. Solenoid 3 2 are switched on then off.

Solenoid 2 4 are switched on then off.

Solenoid 4 3 are switched on then off This results in a more vigorous anti clockwise movement of the product over the sieve plate 8, Mode 5, Solenoids 3, 2, and 4 are switched mon then off.

This results in a vigorous vertical movement of the product.

The microprocessor also controls the Frequency of the on/off sequences for the selected "Mode" and the length of time the selected "Mode" runs for.

Operator Programming.

Sieving characteristics are a function of product to be sieved and product size. The microprocessor systei enables the operator to optimise and store sieving sequences for at least eight different size's of product. A complete sieving sequence for each size of product can be referred to as a "Script".

A typical sieving sequence or "Scridptf', could consist of the following steps: Step 1 Step 2 Step 3 Step 4 Step S Step 6 Mode 1 at frequency Mode 5 at frequency Mode 3 at frequency Mode 5 at frequency Mode 4 at frequency Mode 5 at frequency 6 HZ for 10 seconds 8 HZ for 2 seconds 10 HZ for 8 seconds 8 HZ for 2 seconds 6 HZ for 20 seconds 4 HZ for 100 seconds A minmum of 200 steps in a "Script" can be stored.

Claims (4)

1. A programmable material sieve comprising of three solenoids spaced at 120 degrees which when powered in various sequences give both circular and vertical movement of product over a sieve plate.

2. A programmable material sieve as claimed in claim 1, incorporating an electronic sensor which converts the physical position of the solenoid into a signal suitable for interfacing to a microprocessor system.

3. A programmable material sieve as claimed in claims I and 2 which incorporates a microprocessor control system which monitors and controls the operation of the solenoids to provided various sequences (Modes) of operation of the solenoids.

4. A programmable material sieve as claimed in claims 1 to 3 which enables the operator of the programmable material sieve to create, optimise, store and run (Scripts) for each size of product A programmable material sieve substantially as herein before described with reference to figures 1 to 4 of the accompanying drawings. Roger Samuel Kent 25 March 2003 Errol Churchman