AU632453B2 - - Google Patents

Description

920424,rslidat.058,wheatboard.le,1 L/i Regulation 3.2

AUSTRALIA

Patents Act 1952 COMPLETE SPECIFICATION FOR A PETTY PATENT 632453 0 o 0 9 Name of Applicant: Actual Inventor(s): Address for Service: AUSTRALIAN WHEAT BOARD 0 .00.D .900o 0000 9 09 DAVIES COLLISON CAVE, Patent Attorneys, 1 Little Collins Street, Melbourne, 3000.

Agitating Device Invention Title: Details of Associated Provisional Application(s): No(s): PK7021/91 filed 3 July, 1991 The following statement is a full description of this invention, including the best method of performing it known to me/us: 1 -2- "AGITATING DEVICE" The present invention relates to an agitating device for use in the sampling of grains.

An assessment as to the quality of a batch of grains can be made by determining the proportion of residue and contaminants within a sample taken from the batch. Standard testing techniques involve the screening of a sample of specific volume on a grid having apertures of a predetermined size depending on the particular grain being sampled. Residue and other contaminants pass through the screen on to a tray beneath the screen and the oO quantity which accumulates on the tray is an indication of the quality of the sample, the quality reducing with increasing amounts of matter collected on the tray. Standard sampling tests require the screen to be shaken at a S 15 specified frequency for a specified number of cycles, for example in the case of wheat 40 cycles at one cycle per second. Th- screen and associated tray are in the form of a hand held unit and the test is frequently performed by shaking the unit manually while held in the hands. This method is liable to significant a: inconsistencies in sampling as the screening action will be dependent on a a 20 whether the operator shakes the unit gently or violently.

It has been proposed to shake the screen/tray unit mechanically to obtain consistency of testing by reciprocating the unit backwards and forwards on a horizontal plane in order to replicate a manual shaking action. However, this has not been found to be entirely satisfactory as sometimes the mass of grains within the unit acts as a body with substantial inertia which only has little movement when the unit is displaced backwards and forwards. This results in an inadequate screening of the grains.

According to the present invention there is provided an agitating device for agitating a screening unit for a sample of grains, said device comprising a 921019,rshspc.008,WHEAT.SPE,2 -3cradle for removably holding the screening unit, and means for rocking the cradle through a predetermined angle at each side of a neutral position at which the screen of the screening unit is substantially horizontal, wherein the means for rocking the cradle comprises a motor operatively connected to the cradle via a drive system which converts rotational movement of the motor into rocking movement of the cradle and control means associated with the motor for providing a predetermined number of rocking cycles of the cradle upon actuation of the motor, and the cradle comprises a base for supporting the screening unit from below and lateral support means for holding the unit against lateral movement during rocking, the configuration of the cradle being such that the unit can be inserted into the cradle from above whereby on :m o insertion it is supported by the base and retained by the lateral support means.

o oAn embodiment of the invention will now be described by way of example only with reference to the accompanying drawings in which:- Figure 1 is a schematic perspective view of an agitating device in 00:0 accordance with the invention; oFigure 2 is a perspective view of a cradle of the device; and 20 Figure 3 is a plan view of the device.

The agitating device in accordance with the invention utilises a rocking action for the screen/tray unit about a horizontal axis and this has been found to provide an effective screening motion which can be accurately repeated for each test. More particularly, the device comprises a support cradle 2 which is carried by a horizontal rocking shaft 4. The cradle comprises a base 6 which supports the Screen/tray until from below and opposed side walls 8 shaped to embrace the peripheral wall of the screen/tray unit which is usually of cylindrical form. Accordingly the cradle 2 can securely support the screen/tray unit for rocking movement without the need for positive securement between 921019,rshspe.008,WHFPI: SPE,3 .iii ii -4the cradle and the unit whereby the unit can quickly be inserted into and removed from the cradle 2. The spacing between the two side walls 8 is adjustable to permit the cradle 2 to be adapted to suit different sizes of screen/tray unit and even different shapes of unit.

The rocking shaft 4 is driven by an electric motor 10 via a reduction gear 12 and crank links 14 and 16 to oscillate uniformly about a neutral position in which the base 6 of the cradle and hence the screen of the screen/tray unit is substantially horizontal. The crank link 14 is mounted eccentrically at its inner end on a drive disc 18 at the output of the reduction gear 12, the outer end of the link 14 being coupled to the link 16 which extends transversely from the rocking shaft 4. The drive speed as determined by the output speed of the reduction gear 12 is such as to cause the rocking shaft 4 and hence the cradle 2 to oscillate at the rate of one cycle per second o 15 and in the preferred embodiment the dimensions of the crank links 14, 16 between the output of the reduction gear 12 and the rocking shaft 4 are such eqoee as to cause the rocking shaft 4 to pivot through an angle of approximately 30 0 0 at each side of the neutral position, The drive system may incorporate a facility for adjusting the angle of oscillation for example by varying the eccentricity of the crank link 14 on the drive disc 18.

o The device incorporates a control unit which causes the device to n. operate over a predetermined number of cycles, for example 40 cycles at each actuation. The control unit may include a counter to display the number of cycles and the control unit may include means for varying the number of oscillatory cycles performed at each actuation. The rocking action provided by the device causes the grains to move continually along the screening surface with a tumbling action and this provides an effective screening action which is accurately repeatable from sample to sample. The device is relatively small and compact and readily be 920424,rshspe.008,WHEAT.SPE,4 transported from site to site for testing purposes.

The embodiment has been described by way of example and modifications are possible within the scope of the invention.

04 4 #40 0 00 000 C 000000 0000 00 0000 0 0.0, 00 0 920424,rshspe.008,WHEAT.SPE,5

Claims (4)

1. An agitating device for agitating a screening unit for a sample of grains, said device comprising a cradle for removably holding the screening unit, and means for rocking the cradle through a predetermined angle at each side of a neutral position at which the screen of the screening unit is substantially horizontal, wherein the means for rocking the cradle comprises a motor operatively connected to the cradle via a drive system which converts rotational movement of the motor into rocking movement of the cradle and control means associated with the motor for providing a predetermined number of rocking cycles of the cradle upon actuation of the motor, and the cradle comprises a base for supporting the screening unit from below and lateral support means for holding the unit against lateral movement during rocking, the configuration of the cradle being such that the unit can be inserted into the cradle from above whereby on insertion it is supported by the base and retained by the lateral support means.

2. An agitating device according to claim 1, wherein the support means comprises opposed supports relatively adjustable to permit adjustment in the size of the cradle. a a DATED this 12th day of October, 1992. AUSTRALIAN WHEAT BOARD By its Patent Attorneys: DAVIES COLLISON CAVE 921019,rshspe.008,WHEAT.SPE,6 1 O 1 ABSTRACT An agitating device for use in the sampling of grains comprises a rocking cradle which removably supports a screening unit for holding the grain sample.

A motor-actuated drive system rocks the cradle through a predetermined number of cycles at each actuation in order to provide a regular screening action which ensures uniformity of screening from sample to sample.

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