AU638422B2 - Metering apparatus - Google Patents

Description

AUSTRALIA

PATENTS ACT 1952 COMPLETE SPECIFICATION 538422 Form

(ORIGINAL)

FOR OFFICE USE Short Title: Int. Cl: Application Number: Lodged: k

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S~r Complete Specification-Lodged: Accepted: Lapsed: Published: Priority: Related Art: TO BE COMPLETED BY APPLICANT Sb

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Name of Applicant: Address of Applicant: Antun ZILIC 389 POLICE ROAD

MULGRAVE

VICTORIA 3170

AUSTRALIA

Actual Inventor: Address for Service: GRIFF-IT-H -HAC-K CG 601 St. Kilda Road, Melbourne, Victoria 3004, Australia.

Complete Specification for the invention entitled: METERING APPARATUS The following statement is a full description of this invention including the best method of performing it known to me:- 2 9 5 \METERING

APPARATUS

5 This invention relates to appa~rstus for dispensing metered quantities of material. The use of material herein o includes various forms of materials and may, for example, include materiel. in granular or powdered form.

One particular application of the present invention relates to plastics moulding machines and to the dispensing of colour pigment used in the moulding process. It will be convenient to hereinafter describe the invention with reference to this particular application, however, it is tc be understood that this is not to be considered as a limitation oo I o understood ti~at this is not to be considered as a limitation on the scope of the invention. It will be appreciated that the metering apparatus of the present invention could be used in a wide variety of applications.

One of the problems associated with plastics moulding is controlling of the amount of colour pigment supplied to the plastics mixture so as to ensure a consistent colour in the product produced. .Currently used metering devices generally comprise a feed auger or screw which feeds the pigment material to a zone where it is iixed with the plastics material prior to processing. The amount of pigment fed to the plastics iraterial is dependent on the time and/or speed of operation of the pigment feed auger. Such metering devices suffer from the disadvantage that it is difficult to supply precise quantities of pigment for mixing with the plastics material and further the auger tends to become clogged and often require cleaning.

It is. an object of the present invention to provide an improved metering device which enables 20 relatively precise quantities of a material to be dispensed as well as being simple in operation and easy to maintain.

According to the present invention there is provided apparatus for dispensing metered quantities of particulate material, the apparatus comprising a main body having a feed inlet and a delivery outlet, a metering device comprising a plate including a metering chamber of S" selected capacity, the plate being displaceable relative to the main body between a filling position in which the see: chamber is aligned with the feed inlet so that material can be fed into the chamber and a delivery position in which the chamber is aligned with the delivery outlet through which the material in the chamber can be dispensed therefrom, cutter means disposed at the feed inlet which R A4\ enables material which may be projecting out of the chamber to be sliced cleanly away as the metering plate moves from the filling position to the delivery position and drive means controlled by an adjustable timing mechanism to cause reciprocal movement of the plate between the filling and delivery positions whereby adjustment of the timing mechanism controls the rate of reciprocal movement of the plate to meter the quantity of delivery of particulate material delivered by the apparatus.

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4 In one form, the main body of the metering device may comprise a main support plate or plates having the feed inlet and dispensing outlet therein. The feed inlet is preferably operatively connected to a hopper which may be mounted to the main support plate in any suitable fashion.

The dispensing outlet is preferably in operative communication with a delivery line which is adapted to deliver the dispensed quantity of material to a suitable location such as in the particular application referred to earlier a zone where it is mixed with plastics material prior to moulding. In a preferred form, the metering device is in the form of a plate which is slidable relative to the main body between the fillng position in which the chamber is aligned with the feed inlet and the dispensing position in which the main chamber is 15 aligned with the dispensing outlet. The main body which is r. discussed above may be in the form of a main support plate, may comprise two plates which are spaced apart so that the metering plate is sandwiched therebetween and is capable of slidable movement relative thereto. a another arrangement, 20 the main support plate may have a slot therein in which the metering plate is disposed and movable therealong.

S disposed at the feed inlet which ens erial which may be projecting out of i 6n er to be sliced cleanly away as the 25 mv -m h illing piLiu Lu Lhe di~'m iii.anb- Preferably, the cutter means is in the Sform of a generally annular disc having a cutting inner peripheral edge disposed immediately adjacent the metering plate. Preferably, the disc is adapted to be rotatable so that the position of the cutting edge can be relocated.

The metering device is preferably provided with a plurality of metering chambers, each chamber being of different selected capacity so that the metering device can be used in various orientations to provide different selected metered quantities of material to the dispensing outlet.

K s F d -0 Preferably, the drive means comprises a piston/cylinder assembly which is in the preferred form comprises a pneumatically driven piston having a piston rod operatively connected to the metering device. Suitable control valve means is provided for causing reciprocating movement of the piston. The apparatus may further include a timer mechanism for controlling the frequency of reciprocation of the piston so that the frequency of movement of the metering device between the filling and dispensing positions can be changed.

The apparatus may further include an actuating means for actuating the drive means at a selected time.

The actuating means may be in the form of a solenoid switch responsive to the operation of some other apparatus such as, for example, the feed mechanism of a moulding macnine.

According to the present invention there is further provided plastics moulding apparatus comprising a plastics moulding machine having a feed head that delivers Vow a mixture of plastics and pigment to the moulding machine, 20 the feed head being fed by a primary hopper containing the plastics material and a secondary hopper containing the pigment, the outlet of the secondary hopper being coupled to the outlet of the primary hopper via an apparatus for dispensing metered quantities of pigment in particulate form, the apparatus comprising a main body having a feed inlet coupled to the outlet of the secondary hopper and a delivery outlet coupled to the outlet of the primary hopper, a metering device comprising a plate including a metering chamber of selected capacity, the plate being displaceable relative to the main, body between a filling position in which the chamber is aligned with the feed inlet so that pigment can be fed into the chamber and a delivery position in which the chamber is aligned with the 9\ delivery outlet through which the pigment in- the chamber can be dispensed therefrom, cutter means disposed at the feed inlet which enables material which may be projecting out of the chamber to be sliced cleanly away as the metering plate moves from the filling position to the delivery position and drive means controlled by an adjustable timing mechanism to cause reciprocal movement of the plate between the filling and delivery positions whereby adjustment of the timing mechanism controls the rate of reciprocal movement of the plate to meter the quantity of delivery of particulate material.

In order to enable a clearer understanding of the invention drawings illustrating an example embodiment are attached and in those drawings: Figure 1 is a schematic sectional side elevation of a metering apparatus according to the present invention with the metering device in the filling position; Figure'2 is a similar view to that of Figure 1 with the metering device in the dispensing position; Figure 3 is a plan view of one form of metering

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S S device; Figure 4 is a plan view of another form of metering device; and e S Ser 6 Figure 5 is a schematic side elevation of a moulding machine incorporating a metering apparatus.

Referring to Figure i, the metering apparatus generally indicated at 1 comprises a main body 3 having a main support plate 4 which has two spaced apart sections with a slot 5 forming a guide track therebetween. The main body 3 of the apparatus includes a feed inlet 7 which is in communication with a hopper 12 and a dispensing outlet 8 which is in communication with a delivery line 15. The hopper 12 is mounted to the main support plate by mounting plate 13 located by blocks 14. An annular disc 9 having a cutting edge 10 is S disposed within the feed inlet 7.

A metering device 16 in the form of a flat plate 18 is disposed within the slot 5 and is slidably movable relative 15 to the main support, plate 4 between a filling positicin (Figure 1) and a dispensing position (Figure The plate 18 has a 'r chamber 17 therein of preselected capacity. As can be seen in Figure 1, when in the filling position, the chamber 17 is in communication with the feed inlet 7 and is adapted to receive 20 material from the hopper therein. When in the dispensing o. position, the chamber 17 is disposed above the dispensing S outlet and therefore the material can be discharged to the delivery line. The cutting edge 10 on disc 9 ensures that no material becomes jammed between the metering plate 18 of the 25 main support plate 4.

As can be seen in Figure 3 the metering element 16 which is shown in the form of a flat rectangular plate 18 comprises four separate chambers 17a, 17b, 17c, and 17d each being of selected and different capacities. It will be appreciated by appropriately orienting the particular chamber with respect to the feed inlet and dispensing outlet, the amount of material dispensed can be varied to suit the requirements of the operator.

The apparatus further includes drive means comprising a piston/cylinder assembly 21 with a piston rod 22 being operatively connected to the metering plate 18 by means 7 of connecting block 24. A control valve mechanism 25 controls the movement of the piston and a timer 26 is adapted to vary the frequency of reciprocation thus providing a further variation and control on the metering operation.

Whilst in the embodiment described above with reference to Figure 1 to 3, a rectangular plate 18 that completes a reciprocating motion is disclosed as the metering element, there are restraints on the speed at which a plate of this kind can reciprocate. Thus, in situations where a greater output is required entailing higher speeds it is envisaged that this invention will also embrace the use of a 'e g..

S circular rotatable plate 60 (Figure 4) with a plurality of apertures 61 defining chambers equally spaced on a common pitch circle. Although not shown in Figure 4, the plate 60 is 15 driven by a variable speed D.C. electric motor through a See.

reduction gearbox, thereby allowing the plate 60 to be rotated at much greater speeds than can be obtained from reciprocal motion. To ensure continual and constant distribution it is further understood that a second array of apertures defining 20 cavities (not shown) may be positioned between the first array on a pitch circle that is smaller than the pitch circle of the first array to ensure continuity of apertures moving over the dispensing outlet. A further embodiment to induce improved versatility and to compensate for the inaccuracies that are S 25 inherent in variable speed D.C. motors operating through reduction gearboxes, a series of shutters 70 are superimposed over the apertures 61 and coupled to the circular plate 60 via pins 71 that move in slots 72 in the shutters 70, whereby rotation of the plate 60 in the reverse direction causes the pins 71 to cause the shutters 70 to rotate relative to the plate whereby the shutters move from either a position where they extend partially over the apertures 61 in the plate 60 or a position where they are clear of the apertures 61 in the plate 60. By varying the effective cross-sectional area of the apertures 61 in the plate 60 the volumes of the chambers are changed so that release of material can be adjusted and I 8 this can, in effect, compensate for a situation where the speed of the plate cannot be accurately slowed down. In other words, to reduce delivery the plate can continue to rotate at the same speed, that is a speed at which a variable speed motor operates efficiently, but is reversed in direction thereby causing the shutters 70 to partially close the apertures 61 to reduce the discharge rate.

The apparatus 1 of the present invention is particularly suitable for use with a plastics moulding machine and as shown in Figure 5. The moulding machine comprises a feed hopper 51 for the plastics material, and a feed head 53 for delivering the mixture to a die 55. The feed head may comprise a rotatable plunger which receives the plastics material (and pigment) and forces it into the mould or die. The metering apparatus 1 is positioned adjacent the main feed hopper 51 and is arranged to deliver the colour pigment to a region where it mixes with the plastics material prior to entering the feed head 53.

ws* Actuation of the metering apparatus may be effected by

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20 connection to a suitable solenoid valve which causes the 0 metering apparatus to be operated when the feed head is filling with the plastics material.

Finally, it is to be understood that the inventive concept in any of its aspects can be incorporated in many different constructions so that the generality of the preceding description is not to be superseded by the particularity of the attached drawings. Various alterations, modifications and/or additions may be incorporated into the various constructions and arrangements of parts without departing from the spirit and ambit of the invention.

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Claims (8)

1. Apparatus for dispensing metered quantities of particulate material, the apparatus comprising a main body having a feed inlet and a delivery outlet, a metering device comprising a plate including a metering chamber of selected capacity, the plate being displaceable relative to the main body between a filling position in which the chamber is aligned with the feed inlet so that' material caix be fed into the chamber and a delivery position in which the chamber is aligned with the delivery outlet through which the material in the chamber can be dispensed therefrom, cutter means disposed at the feed inlet which enables mate;ial which may be projecting out of the chamber to be sliced cleanly away as the metering plate moves from the filling position to the delivery position and drive 15 means controlled by an adjustable timing mechanism to cause reciprocal movement of the plate between the filling and delivery positions whereby adj'stment of the timing mechanism controls the rate of reciprocal movement of the plate to meter the quantity of delivery of particulate material delivered by the apparatus.

2. The apparatus according to Claim 1 wherein the main body defines a slot in which the plate is slidably located and the metering chamber comprises an aperture in *O the plate which is positioned below the feed inlet in tle filling position and abov( the delivery outlet in the delivery position.

3. Th apparatus according to either Claim 1 or 2 wherein the cutter means comprises an annular disc having an arcuate cutting inner peripheral edge disposed immediately adjacent the metering plate.

4. The apparatus according to Claim 3 wherein the t\ disc is adapted to be rotatable so that another arcuate position of the inner peripheral edge is from the cutting edge. 'he apparatus according to any one of the preceding claims wherein the drive means comprises a piston/cylinder assembly.

6. The apparatus according to Claim 1 wherein the metering device is in the form of a circular plate having a plurality of chambers equally spaced around the common pitch circle, the plate being rotatable so that the chambers move between the filling position and the delivery position.

7. Plastics moulding apparatus comprising a plastics moulding machine having a feed head that delivers a mixture of plastics and pigment to the moulding machine, the feed head being fe'd by a primary hopper containing the plastics material and a secondary hopper containing the pigment, the cutlet of the secondary hopper being coupled to the outlet of the primary hopper via an apparatus for dispensing metered quantities of pigment in particulate form, the apparatus comprising a main body having a feed inlet 10 coupled to the outlet of the secondary hopper and a delivery outlet coupled to the outlet of the primary hopper, a metering device comprising a plate including a metering chamber of selected capacity, the plate being displaceable relative to the main body between a filling f e 15 position in which the chamber is aligned with the feed inlet so that pigment can be fed into the chamber and a delivery position in which the chamber is aligned with the *S* delivery outlet through which the pigment in the chamber can be dispensed therefrom, cutter means disposed at the S 20 feed inlet which enables m~terial which may be rojecting out of the chamber to be sliced cleanly away as the metering plate moves from the filling position to the delivery position and drive means controlled by an adjustable timing mechanism to cause reciprocal movement of the plate between the filling and delivery positions whereby adjustment of the timing mechanism controls the rate of reciprocal movement of the plate to meter the quantity of delivery of particulate material.

8. Apparatus for dispensing metered quantities of a material substantially as described herein with reference to and as illustrated in the accompanying drawings.

9. Plastics moulding apparatus substantially as described herein with reference to and as illustrated in the accompanying drawings. DATED this 21st day of April 1993. ANTUN ZILIC By Its Patent Attorneys GRIFFITH HACK CO. Fellows Institute of Patent Attorneys Sof Australia F 0 *S *005 0 S. S S, S S. S S