A STONE PICKER

Abstract: A stone picker has a wheel-mounted tractor-drawn frame (10) with a digging assembly of tines (33) for excavating stones as the machine advances, a rotary feeder assembly of flails (25) being driven to impel the stones onto an elevator (36) which discharges them into a bin (22) on the frame, the elevator (36) including a series of spaced parallel shaker bars (42) overlying transverse cleats (39) carried by driven endless chains (38) and with fingers (40) extending up between the shaker bars (42) to move the stones along the shaker bars (42) which are vibrated by the elevator cleats (39) on which they rest to dislodge from the stones adherent soil and small stone particles which fall to earth between the shaker bars (42).

Description: Title: "A STONE PICKER" BACKGROUND OF THE INVENTION (1) Field of the Invention This invention relates to a stone picker. (2) Brief Description of the Prior Art Various types of stone pickers are well known, such an implement being made- to be drawn by a tractor across stony ground and -to excavate stones, and to elevate and discharge them into a stone bin or container from which they may be subsequently unloaded. SUMMARY OF THE PRESENT INVENTION The general object of the present invention is to provide an implement of this general type, which is particularly effective in dislodging adherent soil from the stones and discharging it, together with small stones below a predetermined size, before larger stones are discharged to the container. Another object achievable in preferred embodiments of the invention is to provide such an implement which may be readily modified as and when required to vary the grading of stones retained for collection in the stone container. With the foregoing and other objects in view, the invention resides broadly in a stone picker of the type having a mobile main frame, digging means on the main frame for excavating stones as the main frame is advanced, an elevator for receiving excavated stones and discharging them to a stone container and feeder means for impelling stones excavated by the digging means onto the elevator, wherein the ' elevator includes a series o endless-chain- mounted cleats transverse of the elevator, a series of spaced longitudinal shaker bars overlying the cleats, fingers mounted on the cleats and extending up between the shaker bars and means for driving the endless chains to advance the cleats so that the fingers elevate stones over the shaker bars ' . Preferably the shaker bars are secured at their lower' front ends and are otherwise free to vibrate above the cleats, accelerating the dislodging of soil adhering to the stones. Preferably the feeder means includes a rotary shaft mounted transversely above the digging means, a plurality of sets of flails being mounted adjacently on the shaft, each set including a hub and a number of flexible flail rods secured to and extending from the hub, and means for driving the shaft. The flail rods are preferably curved away from the direction of rotation, and they assist in breaking up the soil to separate the stones as well as acting to impel the stones towards the elevator. Other features of the invention will become apparent from the following description. BRIEF DESCRIPTION OF THE DRAWINGS In order that a preferred embodiment of the invention may be readily understood and carried into practical effect, reference is now made to the accompanying drawings, wherei :- FIG. 1 is a side elevational view of a stone picker according to the invention, FIG. 2 is a plan view of the stone picker, and FIG. 3 is a detail side view to larger scale of of the digging, feeding and elevating means of the stone picker. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT ■ The implement illustrated includes a generally " rectangular main frame 1.0 with parallel side members 11 and a central member 12. At its front the main frame has a draw-bar 13-, braced by oblique stays 14 and fitted with a universal- oint hitch 15 for ^ connection to the tow-bar (not shown) of a tractor. The main frame is supported near to its rear end on a pair of pneumatically-tyred wheels 16. Each of the main frame side members 11, and the central member 12, is in two parts pivotally connected " about a transverse axis at 17. Hydraulic rams 18 connected between pairs of standards 19 and 20 on the two parts of the side members 11 may be extended or retracted to raise or lower the middle part of the main frame 10. Within the main frame, two stone picking assemblie indicated generally at 21 are mounted to both sides of the central member 12, for picking up stones, elevating them and discharging them.into a large bin or stone- container 22 on the rear of the main frame. Each of the stone picking assemblies 21 includes a feeder assembly having a transverse shaft 23 which carries a series of spaced hubs 24 on each of which a series of curved and back-swept flails 25 of high-tensile steel are fixed at their inner ends by clamps 26. Each of the hubs 24 is angularly off-set relative to the next so that, across the assembly, t'he flails are in staggered arrangement, as indicated in full and in broken outline in FIG. 3. To prevent undue stressing of the flails 25 near to their attachment to the hubs, each hub is provided with a series of stop arms 25a against which the flails 25 are brought when flexed beyond a predetermined amount . The power take-off of the towing tractor is connected by shafts 27 and universal couplings 28, and through an overload clutch 29, to a countershaft 30 mounted above the middle part of the main frame 10. The countershaft 30 drives, through a chain drive 31 and gearbox 32, the shafts 23 of the two feeder assemblies. As these assemblies are rotated, the flails 25 are swept from front to ' rear over a digging assembly co-nsisting of a series of forwardly extending parallel tines 33 mounted between a pair of upright side plates 34, each of the tines having at its front a hardened digging tooth 35. Each digging assembly of tines 33 leads at its rear to an elevator 36 which has, between a pair of parallel upright side plates 37, a pair of sprocket-mounted endless chains 38 interconnected by transverse carrier cleats 39• To each of the cleats 39 there are fixed a number of fingers 40 perpendicular to the chains. The rear end of each of the digging tines 33 is bolted or otherwise fixed at 41 to the front end of a shaker bar 42 of similar width to the tine. The shaker bars 42 overlie the carrier cleats 39, and fingers 40 of the upper run of the elevator extend upwardly through the space between succeeding shaker bars 42. The shaker bars, fixed only at their front ends and resting on the elevator carrier cleats 39, are free to vibrate as the elevator is operated " . The two elevators are driven from the countershaft 30 by a chain drive 43, a longitudinal shaft 44 including an overload clutch 45, a gear box 46 and a pair of chain drives 47. As the stone picker is drawn forward by a tractor, the two digging assemblies of tines 33, assisted by the soil-breaking action of the flails 25 of the rotating breaker assembly, dig stones which are carried back on the tines and swept from them onto the elevators by the flails 25, which assist in separating adherent soil from the stones. The working depth of the tines 33 is controlled by the hydraulic rams 18; Stones received on the elevators 36 are carried upward by the fingers 40. The shaker bars, fixed only at their front ends, are subject to a good deal of vibration which assists in shaking.soil free from the stones, the soil and small stones falling through the elevator to the ground. The stones are discharged from the heads of the two elevators into the bin- 22, the upper -rear corners of which are pivoted at 48 to a pair of oblique slides 49, the bottom corners of the bin being slidably mounted on a pair of side ramps 50. A pair of hydraulic rams 51 are connected between the main frame side members 11 and the upper parts of the bin 22 so that, when these rams are extended, the bin is first lifted obliquely to the rear. When the slides 49 have been extended to their limits, further extension of the rams 51 causes the bin 22 to be swung up about its pivots 48 to discharge the load of stones accumulated therein. Stone pickers according to the invention will be found to be very effective in achieving the objects for which they have been devised. The flails 25 break up soil, separating stones and facilitating their excavation by the tines 33, and feeding the stones over the tines and onto the elevators, on which the spacing of the shaker bars 42 grades stones 'to be fed to the bin and allowing smaller stoney particles to return to ground. This spacing may be readily varied by. eplacing one set of shaker bars with others of wider or narrower construction. The vibration of the shaker bars over which the stones are removed by the fingers 40 will be found very effective in dislodging soil adhering to the stones. The stone picker may be of self-propelled rather than tractor-drawn type, and this and many other modifications of constructional detail and design, which will be readily apparent to skilled persons, may be made in the implement without departing from the scope and ambit of the invention hereinafter claimed. OMPI _> , WIPO -.& <ξfκNAτ\0_ζ>

Claims: CLAIMS : 1. A stone picker of the type having a mobile main 'frame, digging means on the main frame for excavating stones as the main frame is advanced, an elevator for receiving excavated stones and discharging them to a stone container, and feeder means for impelling stones excavated by the digging means onto the elevator; wherein the elevator includes: a series of endless-chain-mounted cleats transverse of the elevator, a series of spaced longitudinal shaker bars overlying the cleats, fingers mounted on the cleats and extending up between the shaker bars, and means for driving the endless chains to advance the cleats and fingers so as to elevate stones over the shaker bars. 2. A stone picker according to Claim 1 wherein: the shaker bars are secured at their lower front ends and are otherwise free to vibrate above the cleats. 3. A stone picker according to Claim 1 or Claim 2 wherein: the digging means includes a transverse series of spaced interconnected tines, and each of the tines is fixed at its rear end to the front end of one of the elevator shaker bars. 4. A stone picker according to Claim 1 or Claim 2 wherein: depth control means are provided, for adjusting the working depth of the digging means or for raising it to inoperative travelling position.. 5. A stone picker according to Claim 4 wherein: the main frame has attachment means at its front for connection to a tractor, is supported at the rear on wheels and includes front and rear sections hingedly _ . OMPI interconnected above the digging means, and the depth control means includes hydraulic means for varying the angular relationship of the said sections to raise or lower the digging means. 6. A stone picker according to Claim 1 or Claim 2 wherein the feeder means includes: a rotary transverse shaft mounted on the mai-n frame above the digging means, a plurality of sets of flails mounted adjacently on the said shaft, each set including a hub and a number of flexible flail rods secured to and extending from the hub, and means for driving the said shaft. 7. A stone picker according to Claim 6 wherein: each of the flail rods is at one end secured tangentially to a hub and is curved towards its other end in the direction away from the direction of rotation. 8. A stone picker according to Claim 1 or Claim 2 wherein: the stone container is mounted on the rear of the main frame for tilting about a transverse axis, and means are provided for tilting the stone container to discharge stones therefrom.

Inventors: BROWN WAYNE JOHN, BROWN, WAYNE, JOHN
Applicants: BROWN WAYNE JOHN, BROWN, WAYNE, JOHN
Application year: 1984
Main classification: A01B43
IPC codes: A01B43