GB2285938A - Throwing wheel for an abrasion machine having separable core to enable reversible mounting in the machine so that both blade faces can be used - Google Patents

Abstract

The wheel has back and front plates 12, 14, and six throwing blades 16 therebetween, the blades and plates being integral, and a separable core 24 having openings for inflow and outflow of particles and which is shaped to interfit with at least one of the plates eg. by having tabs (26 Fig. 2) which fit in cut-outs 32, 36 of notches 30, 34 around the edge of central openings 17, 33 in the front and the back place, respectively, so that when the wheel is mounted on the drive the core and the rest of the wheel are held in position by releasable holding means eg. a bolt passing through a hole 27 in the base plate of the core. By turning the wheel over and using the other set or cut-outs 32 or 36, the mounting of the wheel in an abrasion machine can be reversed, allowing both faces of the blades 16 to be used. The notches 30, 34 allow the tabs on the core to pass through one central opening before engagement with the cut-outs of the notches of the other opening. <IMAGE>

Description

THROWING WHEEL FOR AN ABRASION MACHINE This invention relates to abrasive throwing wheels for machines in which particulate abrasive material is propelled onto a surface or surfaces. All such machines are described herein as "abrasion machines", although the abrasive material may in some instances have an effect other than a primarily abrasive effect, for example a cleaning effect. The machines may be static, in which case an article to be treated is placed in an enclosure into which the material is propelled, or mobile, for example as shown and described in GB-A-1575477, GB-A-1575478 and GB-A1542495.

The throwing wheels to which the invention relates are mounted in the machine and are driven for rotation by a drive motor of the machine. The wheels have blades which act to propel the particulate abrasive material.

Known throwing wheels include wheels with parallel spaced front and back plates, between which individually demountable blades are secured: see, for example, GB-A-1328417 and US-A-3785105. One-piece, cast wheels having a single back plate are also known: see, for example, GB-A-2150471.

The present invention provides a throwing wheel for an abrasion machine, comprising spaced, substantially parallel first and second annular plates, means for releasable mounting of the wheel on a drive means of an abrasion machine for rotation of the wheel about an axis extending substantially perpendicular to the first and second plates, and a plurality of circumferentially- spaced, generally radially-extending throwing blades extending between the confronting surfaces of the first and second plates, wherein the blades and the plates are integral to form a first part of the wheel which has a central core which is located radially inwardly of the blades and which has an axial opening for inflow of particulate material and a plurality of outwardly-facing openings for radiallydirected outflow of the material, the core being separable from the first part of the wheel and shaped to interfit with at least one of the plates so that, when the wheel is mounted on the drive means of the machine, the core, together with the plates and blades, is held in position on the drive means by the releasable holding means.

The releasable holding means preferably act on the core. In such a case, the interfitting of the core and the first or second plate ensures that the plates and blades are also held in position on the drive means.

Conveniently, the releasable holding means comprises a bolt which passes through a central aperture in the core into the mounting means.

Preferably, the first plate and the second plate are both shaped to interfit with the core, so that the wheel can be mounted on the drive means in a selected one of two positions, in which the first and the second plates, respectively, are adjacent the drive means.

A suitable interfitting of the core and the or each plate can be provided by a shoulder on one part engaging an abutment surface on the other part.

In another arrangement, the interfitting can be by way of protruding tabs on one part and suitably shaped recesses on the other part.

A suitable material for the blast wheel is chrome iron. Any other material having suitable durability properties may however be used instead.

An embodiment of the invention will now be described by way of example with reference to the drawings, in which: Figure 1 is a perspective view of the blades and plates of a throwing wheel for an abrasion machine, Figure 2 is a perspective view of the core of the throwing wheel of Figure 1, and Figure 3 is a front elevational view of the throwing wheel of Figure 1, Referring to Figure 1, the blade and plate part of the throwing wheel, indicated generally by the reference numeral 10, consists of a first or back plate 12, a second or front plate 14 extending substantially parallel to the back plate and spaced therefrom, and six throwing blades 16. The front plate 14 is annular and has a central circular aperture 17.At its centre, the throwing wheel has a separately-formed cylindrical central core 20 (see Figure 2) for distribution of abrasive material which is fed axially into the core through an axial opening 21, accessible through the aperture 17, and is thrown outwardly therefrom by centrifugal force through six outlet openings 22 formed in the cylindrical wall of the core. The axial opening 21 and the outlet openings 22 together form a continuous annular portion 23 of the core which contributes to its overall strength.

The core 20 has an integral circular base plate 24 which has around its circumference six outwardly projecting tabs 26. The base plate has a central circular mounting hole 27 which can be seen in Figure 3.

Each throwing blade 16 of the wheel extends on an approximately radial path but is shaped so that the radial faces of the blades are concave, the faces being portions of respective circular cylinders having their axes perpendicular to the planes of the front and back plates 12, 14.

The front plate 14 is formed in the edge of the central circular aperture 17 with six notches 30 which are shaped to receive the tabs 26 of the base plate 24 of the core. Each notch 30 has a circumferentially extending side cut-out 32, into which the tabs can be located by rotation of the core relative to the front plate 14.

The back plate 12 also has a central circular aperture 33 which is similarly formed with six notches 34, each having a side cut-out 36. It will be noted however that the cut-outs 36 extend circumferentially in the opposite direction to the cut-outs 32.

A circumferential shoulder 37 extends around the central opening of the front plate 14. The back plate 12 has a corresponding shoulder which is not shown in the drawing.

The mounting of the throwing wheel in an abrasion machine will now be described. Mounting with the back plate 12 secured to the drive means of the machine will be described first.

For this, the core 20 is inserted into the blade and plate part by passing the tabs 26 on the base plate 24 through the notches 30 in the front plate 14 and then into the notches 34 in the back plate 14. With the tabs 26 located in the notches 36, the core is rotated clockwise relative to the blade and plate part so that the tabs 26 become located in the side cut-outs 36 of the notches 34. The two parts are now fitted together and securing of the core to the drive means by a mounting bolt passing through the central hole 27 will secure both parts of the throwing wheel to each other and to the drive means.

To mount the wheel in the machine with its front plate secured to the drive means, the blade and plate part of the wheel is inverted relative to the orientation just described and the core inserted from the opposite side, its tabs 26 passing through the notches 34 around the central aperture 33 of the back plate 12, into the notches 30 of the front plate 14 and then into the side cut-outs 32 of the notches 30.

In either orientation of mounting, the shoulder 37 around the opening 17 or the shoulder around the opening 33 receives the mounting plate of the drive means of the abrasion machine.

It will be noted that, for a predetermined direction of rotation of the drive motor of the machine, opposite faces of the blades of the wheel will be the throwing faces of the blades when the front and when the rear plates, respectively, are mounted on the drive means. The service life of the wheel can thus be effectively doubled by reversing its mounting on the machine. It should also be noted that most abrasion machines are arranged for rotation of the drive means in one direction only. Use of the reverse blade faces by reversal of the direction of the rotation is therefore not a possibility in such machines.

Claims (9)

1. A throwing wheel for an abrasion machine, comprising spaced, substantially parallel first and second annular plates, means for releasable mounting of the wheel on a drive means of an abrasion machine for rotation of the wheel about an axis extending perpendicular to the first and second plates, and a plurality of generally radially-extending throwing blades extending between confronting surfaces of the first and second plates, wherein the blades and the plates are integral to form a first part of the wheel which has a central core which is located radially inwardly of the blades and which has an axial opening for inflow of particulate material and a plurality of outwardly-facing openings for radially-directed outflow of the material, the core being separable from the first part of the wheel and shaped to interfit with at least one of the first and second plates so that, when the wheel is mounted on the drive means of the machine, the core and the first part are held in position on the drive means by the releasable holding means.

2. A throwing wheel according to claim 1, in which the releasable holding means act on the core.

3. A throwing wheel according to claim 1 or 2, in which the first plate and the second plate are both shaped to interfit with the core, so that the wheel can be mounted on the drive means in a selected one of two positions in which the first and the second plates, respectively, are adjacent the drive means.

4. A throwing wheel according to claim 3, in which the first part and the core interfit by engagement of a shoulder on one part with an abutment surface on the other part.

5. A throwing wheel according to claim 3, in which the first part and the core interfit by means of protruding tabs on one part being received in corresponding recesses in the other part

6. A throwing wheel according to claim 5, in which the tabs and recesses are located around the periphery of the core and a central aperture in the first and/or the second plate of the first part.

7. A throwing wheel according to claim 6, in which tabs on the core interfit with recesses on the plate(s).

8. A throwing wheel according to any of claims 5 to 7, in which the tabs are brought into reception in the recesses by relative rotation of the core and the first part.

9. A throwing wheel for an abrasion machine, the wheel being substantially as hereinbefore described with reference to the drawings.