Abstract:
A rotary bowl for separating particles of ore received in the bowl has a drive rotor engaging a bowl outer surface, that rotor being tiltable with the bowl. An idler rotor may be provided to engage the back outer surface, and to cooperate with the drive rotor to provide bowl support. Tiltable frame structure supports the rotors, which may be articulated.

Description:
BACKGROUND OF THE INVENTION 
     In ore concentrators of the type shown in U.S. Pat. No. 1,986,778 to Hinkley, the number of leads employed on the rotating bowl was between about five and ten, so that the size of the center hole to which material is led was minimal. Accordingly, hollow bowl rotating shafts could be used to conduct the material from the center hole and away from the bowl. 
     However, when the size of the machine increased significantly, the number of leads in the bowl increased to between 60 and 100, for example. As a consequence, the size of the central opening and of the hollow shaft increased markedly, and to the point where undesirably large shaft bearings and associated apparatus would be required. 
     U.S. Pat. No. 4,389,308 to Cleland overcomes such problems, and discloses solid rotating shafts for the bowls, characterized by their design for the structural integrity of the system versus a transporting characteristic for concentrates. Accordingly, the need for large size hollow shafts if eliminated. However, at certain times, the high torques required to drive such shafts can become objectionable. 
     SUMMARY OF THE INVENTION 
     It is a major object of the present invention to provide simple, highly effective and improved apparatus overcoming the above problems and difficulties. Basically, the invention comprises: 
     (a) a rotary bowl having rotary surfaces for separating particles of ore received into the bowl, the bowl having a first axis of rotation, 
     (b) first support means mounting the bowl for selective tilting about a second axis, and 
     (c) drive means including a drive rotor suspended by said support means and engaging a bowl outer surface facing away from said axis for rotating the bowl, and a prime mover operatively connected with said drive rotor. 
     As will appear, an idler roller may be suspended by the first support means and also engaging the bowl outer surface, the idler and drive rollers located to also exert supporting forces on the underside of the bowl, and typically cooperating in this mode of operation. Articulated support members are provided for the rollers typically. 
     Further, the first support means may typically include uprights at opposite sides of the bowl; a frame pivotally supported by the uprights, the frame extending at the front and rear of the bowl, and structure extending through the bowl and connected with the frame to allow the bowl to rotate relative to the frame, there being a materials discharge ring at rear center of the bowl, and to which such structure is connected. Bowl tilt may be hydraulically effected, and a hydraulic motor may drive the bowl driving roller. 
     These and other objects and advantages of the invention, as well as the details of an illustrative embodiment, will be more fully understood from the following description and drawings, in which: 
    
    
     DRAWING DESCRIPTION 
     FIG. 1 is front perspective view of ore separator apparatus as disclosed in U.S. Pat. No. 4,389,308; 
     FIG. 2 shows a rear perspective view of the FIG. 1 apparatus; 
     FIG. 3 is an exploded fragmentary perspective of the FIG. 1 apparatus hub and drive shaft; 
     FIG. 4 is a cross-sectional view of the FIG. 1 apparatus assembled hub, drive shaft, and a portion of the bowl; 
     FIG. 5 is a top plan view of bowl support and drive apparatus in accordance with the present invention; 
     FIG. 6 is a side elevation on lines 6--6 of FIG. 5; 
     FIG. 7 is an end elevation on lines 7--7 of FIG. 6, but showing the bowl tilted; and 
     FIG. 8 is an end elevation on lines 8--8 of FIG. 6, the bowl being tilted. 
    
    
     DETAILED DESCRIPTION 
     As described in U.S. Pat. No. 4,389,308, ore separation apparatus includes a rotatable bowl 10 having an inner liner 11 of spiral grooves or riffles and a central outlet or opening 12 for discharging concentrated values of the ore. The apparatus includes cylindrical hub 14 at the periphery of the central opening 12. The hub includes an inner cylinder 13 and an outer cylinder 15 which is integrally connected with a dish-shaped portion 16, the latter being connected at its periphery to frustoconical flange 18 which terminates at outwardly flaring lip 20. Inner cylinder 13 of the hub is comprised of a rigid material, such as steel, to lend structural strength and rigidity to the hub, while outer cylinder 15 is comprised of fiberglass as is the dish-shaped portion 16 of the bowl. The inner cylinder 13 is sized to fit snugly within the outer cylinder, and these two are locked together against rotational or longitudinal slippage by means of set screw 21, as shown in FIG. 4. 
     A series of radially extending stiffening ribs, also comprises of fiberglass, are integrally formed and joined with the outer surfaces of outer cylinder 15 and dish-shaped portion 16 of the bowl 10, as shown in FIG. 2. These ribs serve the dual function of strengthening both the bowl and the hub against both torsional and lateral deformation when heavy loads of ore are in the bowl. 
     A spider means or series of ribs 22 are provided to connect the interior of hub 14 with a central mounting sleeve 24, which is pinned to drive shaft 26 by means of pins 25. Preferably, two sets of ribs 22 radiate outwardly from mounting sleeve 24 at longitudinally spaced apart positions, as shown in FIG. 4. Preferably, at least three ribs, and, more preferably, at least four ribs, are provided near each end of hub 14. By constructing the inner cylinder 13, the ribs 22, and the central mounting sleeve 24 of a strong, rigid material, such as steel, and unitizing these components, e.g., by welding, an exceptionally durable and advantageous hub arrangement can be achieved. 
     The drive shaft 26 is positioned within sleeve 24 a predetermined distance by means of collar 27, and is rotatably mounted by means of forward bearing 28 and rear bearing 30 on table 32. Table 32 also supports a drive motor 34, transmission means 36, gear box 38, and gear means 40 for rotating drive shaft 26 and bowl 10 in a clockwise direction, as viewed in FIG. 1. 
     The table 32 is equipped along its forward portion 42 with traverse axles or journals 44 for pivotally mounting the table in bearings 46. The bearings 46 are mounted upon table support 48 which is comprised of a pair of vertical stanchions 50 and longitudinal runners 52, which are connected by transverse member 54 and braced by transverse braces 56, forward braces 58, and rear braces 60. 
     The axis of rotation of bowl 10 is generally at a low acute angle to the horizontal, but it may be controlled and varied between a substantially horizontal position and a position approaching the vertical by means, e.g., of an hydraulic control system. 
     When the apparatus is used for separating ore, the drive shaft 26 is rotated by motor 34 to turn the bowl 10 in a clockwise direction, as viewed in FIG. 1. Crude ore is fed into the bowl by conveyor 84 and lubricated using water spray means 86. The bowl is equipped with mixing vanes 88 which aid in the distribution and mixing of the ore and water. As the bowl rotates, heavy ore values migrate through spiral grooves 89 to the central opening 12 of the bowl. The spiral grooves 89 (constructed, for example, of rubber) are formed as a part of liner 11, which is secured to the inside of the dish-shaped portion 16 of the bowl. 
     Waste material or gangue is discharged at the lower periphery of the bowl into trough 90, or a chute, which is mounted on support members 92. The support members 92 are connected rigidly to table 42 to pivot therewith. 
     Waste material from the trough 90 is discharged continuously through trough outlet 94 where it may be disposed of (by means not shown). The concentrated ore which leaves the bowl through central opening 12 is received or controlled by concentrated ore receptacle 96 from which it is discharged downwardly and caught in containers or receptacles (not shown). 
     When large loads of ore are fed into the apparatus, very high bending stresses are imposed upon both the bowl and the hub, especially when the axis of rotation of the bowl and hub is maintained at a desirable acute angle to the horizontal. This is aggravated further when very large containers are used, such as those seven or more feet in diameter. By employing at least three, and, preferably, four or more, stiffening ribs 19 radiating outwardly from the outer fiberglass cylinder 15 of the hub 14 and along a major portion of the radius of the bowl-shaped container, excessive deformation of the bowl is prevented. At the same time, tearing or bending of the outer cylinder 15 of the hub is prevented by the stiffening effect of ribs 19, together with the backing provided internally by the rigid cylinder 13. The series of spokes 22 enable the hub and container to maintain their predetermined axial alignment with drive shaft 26. 
     Referring now to FIGS. 5-8, with which the present invention is particularly concerned, the bowl or container 100 itself may have the same construction as bowl 10. It also includes the ring or annular hub structure shown in FIGS. 3 and 4, and indicated generally at 101. The bowl first axis of rotation is shown at 102, and is defined by structure 103, as for example a shaft, which extends forwardly to bearing 104 and rearwardly to bearing 105. Thus, the shaft is supported at both ends, and in turn supports the ring or hub 101 via webs 105. A frame 106 includes a front horizontal beam 107, and a rear beam 108 having sections 108a-108e. Bearings 104 and 105 are carried by beams 107 and 108, as shown. The latter are connected by side beams 109 and 110 at the periphery of the bowl. 
     Vertical uprights 111 and 112 are connected with side beams 109 and 110 via pivots 113 and 114 defining a second axis 115. FIG. 8 shows an hydraulic actuator 119 interconnected at 120 and 121 between upright 111 and frame side beam 109 whereby the bowl is mounted for selective tilting about horizontal second axis 115. Note hydraulic fluid pressure control 122, for controlling the actuator. Uprights 111 and 112 may be connected to a base frame 123, which may be supported on wheels 124 thereby to provide trailer support for the bowl, adapted to be towed to ore separation sites as via tongue 125 and towing vehicle (not shown). 
     Also provided is drive means including a drive rotor suspended by the frame, and engaging an outer annular surface 100a of the bowl, for rotating the bowl. Surface 100a faces laterally outwardly, away from axis 102. One such drive roller is shown at 127, having an axis 128 of rotation parallel to axis 102. The roller 127 is driven by a prime mover or motor 129 which may be hydraulically or electrically operated, for example. Motor 129 is shown as also suspended from the frame, an auxiliary member 130 being attached to frame section 108e and suspending both the roller 127 and the motor 129 via a head 130a. The latter is advantageously articulated, as by pivoted connection at 131 to member 130, whereby the head 130a swings in a plane parallel to the plane of FIG. 6, toward and away from the vertical plane 132 that contains axis 102 and bisects the bowl. 
     In similar manner, an idler roller 133 is suspended to engage the bowl outer surface, i.e. the same rotating annular surface 100a that is engaged by roller 127. A second auxiliary member 134 is attached to frame section 108a and suspends roller 133 and mount 136 via a head 134a. The later is advantageously articulated as by pivoted connection at 135 to member 134, whereby head 134a swings laterally toward and away from plane 132. The forwardly projecting roller mount 136 including an axle, is connected to the bottom end portion of head 134a, as shown. 
     It is a feature of the invention that the two rollers 127 and 133, symmetrically located at opposite sides of plane 132, and symmetrically supported by articulated heads 130a and 134a, act also to exert support forces on the underside of the bowl. To this end, the members 130 and 134 may advantageously be interconnected as for example by a connecting rod 138, so as to resist relative spreading of the two rollers 127 and 133. Rod 138 is shown as flexibly connected at 139 to member 130, and as extending through member 134. A compression spring 140 is positioned between the outer side of member 134 and a stop 141 on the end of the rod, whereby the spring forcibly urges the rollers toward one another and against the bowl surface 100a, whereby roller 127 may drive the bowl in rotation, and both rollers may exert supporting forces on the underside of the bowl, whereby the loading on shaft 103 is correspondingly reduced, the bowl having three point suspension aiding its operation. Stop 141 may be threaded to the shaft so as to variably tension the spring 140, whereby the forces exerted by the rollers on the bowl are adjustable, within limits. Also the rollers may skid relative to the bowl, without damage; and drive torque is minimized due to drive roller location. 
     Wheels 124 may be removed at a work site. Chutes 90a are removably supported at 92 to bed frame 167.