1 ROCK BREAKER SUMMARY OF THE INVENTION It is to be recognised that other aspects, preferred fons and advantages of the present invention will be apparent from the present specification including the detailed description, 5 drawings and claims. According to a first aspect of preferred embodiments herein described there is provided arock breaker comprising: a body having a recess for receiving an impactor that is adapted to rotate about an axis extending longitudinally into the recess; the recess including a curved wall extending along the recess; the curved wall having a number of narrow elongate slit 10 type openings each extending around the recess across the curved wall; the slit-type openings being spaced apart in a direction along the body to fonn a series; the impactor including at least one impactor bar that is positioned in an offset position for rotating in a direction along the slit-type openings, in a direction around the recess, with the or each impactor bar extending across the slit-type openings in an adjacent manner 15 Preferably the recess is a cylindrical recess and the at least one impactor bar comprises two elongate impactor bars spaced apart to fit within the cylindrical recess. Preferably the slit-type openings comprise thin cuts made by cutting and removing material from the body. According to a second aspect of preferred embodiments herein described there is provided 20 a rock breaker comprising: a body providing a cylindrical recess for receiving rock; an impactor for rotating about the longitudinal axis of the recess; a plurality of narrow elongate slit-type openings each extending around the recess; the slit type openings being spaced apart in a direction along the body to form a series; the impactor including at least one impactor bar that is positioned in an offset position for rotating in a direction along the slits, 25 in a direction around the recess, with the or each impactor bar extending across the slits in an adjacent manner. RECEIVED TIME 18. APE: 17:YF 2 BRIEF DESCRIPTION OF DRAWINGS In order to facilitate a better understanding of the present invention, several preferred embodiments will now be described With reference to the accompanying drawings, 5 comprising Figures 1 to 11. DETAILED DESCRIPTION OF THE EMBODIMENTS It is to be appreciated that each of the embodiments is specifically described and that the present invention is not to be construed as being limited to any specific feature or element of any one of the embodiments. Neither is the present invention to be construed as being 10 limited to any feature of a number of the embodiments or variations described in relation to the embodiments. Referring to Figures 1 to 5 there is show a rock breaker 10 according to a first preferred embodiment of the present invention. Referring to Figure 1, the rock breaker 10 comprises a body 12 for providing a recess 14 15 for receiving rock. The rock breaker 10 further includes an impactor 16 for rotating at high speed within the recess 14. Referring to Figure 2, the body 12 includes a series 18 of narrow elongate slit-type openings 20. The slit-type openings 20 are formed in the body 12 of the rock breaker 10. The series 18 extends with a regular spacing in the direction the longitudinal axis 22 of the body 12. 20 There series 18 runs nearly the full length of the body 12. Refen-ing to Figure 3 the shape of the impactor 16 is able to relatively neatly fit within the cylindrical wall 24 of the recess 12. The slit-type openings 20 are positioned so as to be adjacent the impactor 16 when the impactor 16 rotates within the recess, as shown in the drawings. The slit type openings are 25 provided by the wall 24 itself. Referring to Figures 3 and 4, the body 12 includes a rock feed hopper portion 26 for a rock feed hopper. The rock feed hopper portion 26 is upwardly disposed and the slit-type openings 20 comprise thin cuts arranged in the series.1.8 along bottom of the body IZ2 RECEIVE) TIME 18. APR 17:55 3 Referring to Figure 2, the thin cuts each extend substantially perpendicular to the length / longitudinal axis 22 of the body/recess. A mount 28 is provided either side of the extension of the slit-type openings 20 across the body 12. The mount is provided for connection to a chute to collect the rock passing through the slit-type openings 20. 5 Referring the Figure 4, the body 1Z includes a closure 30 that is removable to allow separation of the impactor 16 from the body 12. Referring to Figure 5, the impactor 16 includes a central axis 32 and a number of impactor bars 34 arranged around the central axis. The impactor bars 34 are positioned substantially parallel to the central axis 32 in an offset position and are rotated by rotating a shaft 36 10 defining the central axis 32. As shown each impactor bar extends across the slit-type openings in an adjacent manner. The rock breaker provides a breaker for breaking up gold bearing rock into powder fitting through the slit type openings 20. A further preferred embodiment of the present invention is shown in Figures 6 and 7. The 15 embodiment comprises a Gold Rock Breaker Cylinder 38 for processing gold bearing rock, A cylinder 40 is provided comprising a round steel tube, Through the middle of the steel cylinder goes a, shaft 42 which is attached to a bearing and bearing and bearing housing 14 at each end (see Figure 7). At each end of the steel cylinder 40 are steel flanges 46 each with a hole in the centre for 20 the shaft 42 to go through. One end is welded, the other end is bolted so the shaft 42 can slide in and out. On the shaft 42 at each end of the shaft 42 inside the cylinder 40 is a flat steel bar 48 with a hole in each one, so the shaft slides through the middle of these. The flat bar length is nearly the length of the cylinder diameter which gives clearance when rotating. The flat 25 bars are welded to the shaft 42. Welded to theses bars are two more bars 50 of hardened steel, these are the impacted bars. These bars are now welded length ways to the other bars, and will rotate in the cylinder at high speed to break up the rock. On top of the cylinder will be a rock feeding opening 52 which will be cut out to fit the rock hopper 54 which will have a goose neck or elbow shape with a safety flap 55 on top 30 to stop the rocks coming back up. At the bottom of the cylinder will be a series of thin cuts RECFIVFD TIMF 1S APR 1 4 56 nearly the length of the cylinder and when the rock is broken up enough it will then drop through into a container below. The main bearings used will be the four bolt flange bearing and housing which is the bearings that the shaft goes through. The walls thickness and size of the cylinder will be changed, the shaft size, bearing size 5 and the impacter bar size will be changed when a smaller or larger version of the gold rock breaker model is built. Referring again to Figures 6 and 7 there is a rock feed 58. a hopper 6, impactor bars 50 (impact bar), end bars 48 bolted end flange 52, welded end flange 62, and duplex pulley 64. The thin cuts 56 are all the way along the bottom of the cylinder. The bolt flange 66 10 and housing will be the main bearing used. The end bars 48 are flat cross bars welded to the shaft and the impact bars are welded to cross bars rotating at high speed in the round cylinder. Thus the gold rock breaker cylinder comprises a round steel tube having a shaft which is attached to the bearing and bearing housing at each end, At each end of the steel cylinder .5 are steel flanges each with a hole in the centre for the shaft to go through. On the shaft at each end of the shaft inside the cylinder is a flat steel bar with a hole in each one, so the shaft slides through the middle of these. The flat bar length is nearly the length of the cylinder diameter which gives clearance vhen rotating and the flat bars are welded to the shaft. Impacter bars are attached to flat bars. On top of the cylinder there are rock feeding 20 opening and rock hopper which will have a goose neck or elbow shape with a safety flap on top to stop the rocks coming back up. The main bearings used will be the four bolt flange bearing and housing which is the bearings that the shaft goes through Various other features are shown in Figures 8 to 11. Thus as will be apparent there is provided a rock breaker 10 comprising: a body j2 having 25 a recess 14 for receiving an impactor 16 that is adapted to rotate about an axis extending longitudinally into the recess 14. The recess 14 includes a curved wall 14 (lower portion) extending along the recess 14. The curved wall 14 has a number of narrow elongate slit type openings 20 each extending around the recess 14 across the length of the curved wall. The slit-type openings 20 are spaced apart in a direction along the body 14 to form a series. 30 The impactor includes two impactor bar 34 that are positioned in an offset position for RECEIVED TIME 18. APR. 17:5 5 rotating in a direction along the slit-type openings 20 in a direction around the recess 14 with each impactor bar 34 extending across the slit-type openings 20 in an adjacent manner. As would be apparent, various alterations and equivalent forms may be provided without departing from the spirit and scope of the present invention. This includes modifications 5 within the scope of the appended claims along with all modifications, alternative constructions and equivalents. There is no intention to limit the present invention to the specific embodiments shown in the drawings. The present invention is to be construed beneficially to the applicant and the invention given its full scope. 10 In the present specification, the presence of particular features does not preclude the existence of further features. The words 'comprising', 'including' and 'having' are to be construed in an inclusive rather than an exclusive sense. It is to be recognised that any discussion in the present specification is intended to explain the context of the present invention. It is not to be taken as an admission that the material 15 discussed formed part of the prior art base or relevant general knowledge in any particular country or region. RECEIVED TIME 1S APR. 17:55