AU594525B2 - Pulverising mill - Google Patents

Description

594525 Form COMMONWEALTH OF AUSTRALIA PATENTS ACT 1952-62 COMPLETE

SPECIFICATION

(ORIGINAL)

FOR OFFICE USE: Application Number: Lodged: Class Int. Class Complete Specification Lodged: Accepted: Published: Priority: Related Art: *4 a.

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0 N~eiq~of Applicant: *00 Address of Applicant: P~tual Inventor: PO&dE,@s for Service: Coriftlete Specification TO BE COMPLETED BY APPLICANT COMLABS PTY. LTD.

305 South Road, Mile End South, State of South Australia, Commonwealth of Australia PHILLIP ROBERT HARVEY Care of R.K. MADDERN ASSOCIATES, 345 King William Street, Adelaide, State of South Australia, Commonwealth of Australia for the invention entitled: The PLERSN folwnMttmn safl ecito ftILLnetoicudn"h etmtodo efrigi known to 4me. us.

This invention relates to a pulverising mill of 'he eccentric weight type commonly used in ge~ological sampling, and more particularly to improvements to the pulverising bowl thereof.

When it is desired to obtain a sample of rock and analyse that sample for existence of valuable minerals, the rock is usually divided into a number of smaller portions and normally one of these is pulverised in a pulverising mill, by being contained within a container having a base, side walls and a hinged lid, the pulverising being effected by the movement, under centrifugal force, of at least one pulverising member, the most common arrangement being to have an annular ring itself containing a cylindrical block of metal, both being of considerable mass and being of hard metal. The container and the pulverising ring and disc are moved in an orbital manner, by being supported from a base frame with support springs, and having a vibrating frame depending from the container which has on it a disc or arm carried by a shaft journalled in bearings for rotation, the disc or arm however having an eccentric weight such t!,lat when driven by an electric motor coupled to the shaft, the eccentric weight movement providing the motive force to produce the orbital movement which in turn causes the pulverising effect to be achieved.

Normally, the container or bowl is constructed to have fixed walls, i.e. the base and sides are integrally formed; however the disadvantage with such an arrangement is that the whole bowl needs to be replaced when the base is worn (owing to the grinding action of the pulverising member and the rock sample).

The main object of this invention is to provide improvements to obviate the aforementioned disadvantage, and according to this invention, there is provided a pulverising mill of the kind wherein a pulveriser bowl comprising a cylindrical side wall and a bottom wall is supported on a vibrating frame for vibratory movement therewith, the -2improvement wherein the bottom wall of the pulveriser bowl is formed by a horizontal replaceable base wear plate, and wherein the walls are releasably fastened together by releasable fastening means.

In order to more fully explain the present invention, an embodiment is described hereunder in further detail with reference to the accompanying drawings in which: Fig. 1 is a perspective view of a pulverising mill housed in its cabinet according to this embodiment, Fig. 2 is a half vertical sectional view of the mill according to this embodiment, and Fig. 3 is an "exploded" perspective view of the clamping o* mechanism on the pulveriser bowl.

In this embodiment, a pulveriser mill 10 comprises a cabinet 11 in which is enclosed a fixed base frame 12, a vibrating frame 13 suspended for vibratory movement with respect to the base frame 12 by means of a plurality of S support coil springs 15, and an hydraulic motor 16 attached to the lower end of the vibrating frame 13. The cabinet 11 rests on the ground and is secured woo* OP** 4 3 33 -3- 1 to the base frame 12. A pulveriser container or bowl 17 is removably fastened on top of the vibrating frame 13 and projects through the upper surface 19 of the cabinet 11. A tiltable canopy 20 is pivotally mounted to the top of the cabinet 11 and is arranged to enclose the bowl 17 during the operation of the mill The base frame 12 comprises steel frame members 21 and an annular frame member 22 surrounding the vibrating frame 13 near its lower end. The upper surface of the member 22 has welded thereto a series of circumferentially spaced upstanding spigots 23, each of which locates a lower end of a respective spring S.which encircles the spigot 23.

The vibrating frame 13 comprises an upper 5. cylindrical housing 24, and a lower cylindrical housing 25 removably secured thereto. The upper housing 24 comprises an horizontal circular top flange 27 which closes off the upper end of the housing 24 and a depending annulus 28, the outer periphery of the flange d. 27 projecting radially beyond the periphery of the annulus 28. The circumferentially spaced springs oo S resiliently support the vibrating frame 13 from the base frame 12, by being interposed between the radially projecting flange portion 29, of the flange 27 and the annular base frame member 22, the upper ends of the springs 15 being retained in position by depending spigots 30 on the underside of the flange portion 29.

The lower end of the annulus 28 terminates in an horizontal inturned flange 31 to which is secured by screws 32, a circular closure plate 34 on the lower housing 25 which also comprises a depending cylindrical side wall 35 secured, by welding, at its upper end to the closure plate 34. The side wall 35 also terminates at its lower end in an inturned flange 36 to which is removably secured, by screws 37, a motor mounting plate for mounting the hydraulic motor 16 thereto, the motor -4-

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16 depending vertically from the mounting plate The upper housing annulus 28 defines a space within which there moves an eccentrically loaded arm or disc 41 carrying an eccentric weight 42, the arm 41 being secured, e.g. by keying, to a vertical shaft 43 which extends centrally through the vibrating frame 13.

The shaft 43 is journalled for rotation in bearings, in this embodiment being an upper roller bearing 44 contained in a depending hollow boss 45 located centrally on the flange 27 of the upper housing 24, and a lower e. roller bearing 47 also similarly contained in a depending boss 48 which depends from the closure plate 34. Seals 49 protect the bearings 44, 47 against the ingress of ~dust and the like. The upper bearing 44 is housed in the upper housing 24 and rotatably supports the upper end of the shaft 43 whilst the lower bearing 47 is also housed within the upper housing 24 and supports an intermediate portion thereof.

The lower end of the shaft 43 terminates in 2b. one element 50 of a two-part flexible coupling 52, while the other element 53 is secured to the driving shaft 54 of the hydraulic motor 16. The coupling 52 in this embodiment is a known coupling sold under the proprietary :o name of "'Fenner". The respective shaft ends are simply push-fitted into the open ends of the coupling 52.

The container or bowl 17 comprises a replaceable tiat wear base plate 56 and a cylindrical side wall 58, all formed from a hard or hardenable steel,.

the side wall 58 being provided with an outstanding annular lower flange 59 which is bolted in face-to-face relation to an annular ring 60 welded to the upper surface of the upper housing top flange 27. The container 17 is centrally mounted on the vibrating frame 13 and has its wear base plate 56 in contiguous relationship with the flange 27. The container 17 is also topped by a hinged lid 51 in accordance with known ii~ I art, the lid 61 being machined to have a shallow spigot which sealably engages around the inner periphery of the side wall 58 near its upper end. The bowl 17 contains three pulverising rings 62, the inner one of which is placed inside the middle one, which in turn is placed within the outer one, the rings 62 being freely movable over the container base 56 by a sliding action.

The lid 61 is releasably clamped to the container side wall 58 by means of a clamping mechanism 63 which comprises a cast bracket 64 bolted to the top of the lid 61 in proximity to its peripheral edge 0.

a pivotal link 66 pivotally connected at its upper end to the bracket 64, and a pivoted clamp arm 67 pivotally attached at its inner end to the lower end of the link 66. The inner end of the arm 67 carries a cam member eo 70 which co-operates with and engages a cam surface 71 t' formed on a load plate 72 which is fastened by screws 73 to the underside of an upper annular flange 75 on the bowl side wall 58. A series of discoid spring .ZQ. washers 76 laid one on top of the other are interposed between the load plate 72 and the flange 75, such an arrangement being effective to allow some "give" in the S mechanism when in its clamped position and thereby minimise wearing of the parts, in particular the load .25 plate 72. When in the clamped position, the arm 67 moves to an "over-centre" position.

In this embodiment, the vibrating frame 13 is supported by eight coil springs 15 spaced therearound, each of the springs 15 being formed of approximately 7 mm diameter steel wire to have 17 turns and an axial length of 200 mm. Each spring 15 is inclined with respect to the vertical, preferably at an angle of 150.

In use, sufficient geological material is placed into the container 17 so that, upon pulverisation, an homogeneous mixture can be obtained. The lid 61 is closed and clamped, and the hydraulic motor 16 is driven at a speed, preferably in the order of 700 rpm, to thereby vibrate the vibrating frame 13, the rings 62 in turn producing a grinding action so as to pulverise the geological Eample. The sample so pulverised will be in sufficient quantity that it is representative of the mineral content, and an homogeneous mixture of particulate material can be removed from the container for analysis purposes.

The grinding action produced is such that wear S* is confined essentially to the base of the bowl 17, and the rings 62. By having the base plate 56 removably wo located in the bowl, one is able to readily replace it at a relatively low cost in comparison with some prior 5. art pulverisers where the whole grinding bowl is required

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to be replaced.

A brief consideration of the above embodiment will indicate that the invention provides an improved pulverising mill which is of simple design, contains relatively few moving parts and which can be readily f repaired or serviced if need be.

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Claims (3)

1. In a pulverising mill of the kind wherein a pulveriser bowl comprising a cylindrical side wall and a bottom wall is supported on a vibrating frame for vibratory movement therewith, the improvement wherein the bottom wall of the pulveriser bowl is formed by a replaceable base wear plate, and wherein the walls are releasably fastened together by releasable fastening means.

2. In a pulverising mill according to claim 1

9. wherein said releasable fastening means releasably fastens said side wall and said base wear plate, to a support surface on said vibrating frame. 3. In a pulverising mill according to either claim 1 or claim 2 wherein said cylindrical side wall ***oo terminates at its lower end in a circular depending tongue which engages in a circular groove formed in the upper surface of said base wear plate. 4. In a pulverising mill according to claim 2 or claim 3 wherein the underside of said replaceable base wear plate is contiguous with said support surface. A pulveriser bowl substantially as hereinbefore described with reference to and as illustrated in Figs. 2 and 3 of the accompanying drawings. DATED this 6th day of November, 1987. COMLABS PTY. LTD. By its Patent Attorneys, R.K. MADDERN ASSOCIATES. -A* j