EP0186357B1

EP0186357B1 - Tumbling apparatus

Info

Publication number: EP0186357B1
Application number: EP19850308900
Authority: EP
Inventors: Albert Musschoot
Original assignee: General Kinematics Corp
Current assignee: General Kinematics Corp
Priority date: 1984-12-21
Filing date: 1985-12-06
Publication date: 1993-03-03
Anticipated expiration: 2005-12-06
Also published as: EP0186357A3; AU584011B2; AU1465188A; EP0186357A2; JPH067982B2; DE3587147D1; AU573928B2; DE3587147T3; JPH04220156A; EP0186357B2; DK598585A; DE3587147T2; CA1267886A; AU5048085A; DK598585D0

Description

This invention relates to vibratory apparatus and, in particular, to vibratory tumbling machines for mixing materials and for cleaning or shake-out of parts to be processed, such as castings, mouldings or bulk material with or without a working media.
In many foundry operations, separation of sand and scale from castings is required. Typically, the castings are initially tumbled to dislodge foreign matter adhering to the castings. To assist this dislodging, shot may be caused to impinge upon the castings as they are tumbled. An exemplary structure through which dislodging of foreign matter according to the above can be better accomplished is shown in US-A-3793780 in respect of which the inventor, Albert Musschoot, is also the inventor of the present invention.
In the aforesaid US-A-3793780, there is generally described a vibratory apparatus comprising a container having a material supporting surface, mounting means for resiliently mounting the container for unconstrained vibratory movement relative to a mounting surface, and vibration generator means mounted on the container.
More particularly, the material supporting surface is concavely linear in cross-section and the vibration generator means during a shake-out operation to separate, say, sand from castings, will generate vibratory forces to tumble the castings on the concavely linear supporting surface.
In accordance with one aspect of the present invention as claimed, the aforesaid generally disclosed vibratory apparatus is characterised in that the material supporting surface is concavely curved in cross-section with respect to the interior of the container and is either generated about,an axis when constituting a circular arc or is generated about the centres of circles osculating the concavely curved surface, the vibration generator means is mounted on the container offset from the axis or osculating circles centres and generating vibratory forces along a linear path offset from the axis or from the osculating circles centres, the vibration generator means and the container having a centre of gravity offset from the axis or from the osculating circles centres of the container, the vibratory generator means and the linear path of vibratory forces being on the same side of the centre of gravity, the vibratory forces vibrating each point on the material supporting surface along segments of circles which do not conform to the curvature of the curved material supporting surface at the related point, each circle segment having a centre of rotation which lies at a position spaced from the axis or from the osculating circles centres and from the centre of gravity and on the opposite side of the axis or the osculating circles centres of the container from the linear path of vibratory forces.
The aforesaid US-A-3793780 also generally discloses a method of operating a resiliently supported vibratory material handling container which comprises generating vibratory forces along a linear path and transmitting the forces to the container with the linear path displaced to one side of the centre of gravity of the container to cause the container to vibrate.
In accordance with another aspect of the invention as claimed, the aforesaid generally disclosed method is characterised in that the container has a material supporting surface which is concavely curved in cross-section with respect to the interior of the conveyor and is either generated about an axis when constituting a circular arc or is generated about the centres of circles osculating the concavely curved surface, the linear path along which the vibratory forces are generated being offset from the axis or from the osculating circles centres, the vibration generator means and the container having a centre of gravity offset from the axis or from the osculating circles centres of the container, the vibration generator means and the linear path of vibratory forces being on the same side of the centre of gravity, the vibratory forces vibrating each point on the concavely curved material supporting surface along segments of circles which do not conform to the curvature of the concavely curved material supporting surface at the related point, each circle segment having a centre of rotation lying at a position spaced from the axis or from the osculating circles centres and from the centre of gravity and on the opposite side of the axis or the osculating circles centres of the container from the linear path of vibratory forces.
Both the aforesaid aspects of the present invention have the advantage of resulting in improved tumbling of a batch of material (which may be castings with or without working media) in the container which may also be used to mix materials of different characteristics in a highly efficient manner. The material in the container is tumbled not only due to the coefficient of friction of the material with the supporting surface of the container, but also due to the angle of attack between the material and the supporting surface at any given point because the material in contact with or close to the supporting surface will follow the segmented circular path of that point which is different from the curved profile of the supporting surface at that same point.
The angle of attack between the material and the container can be varied to vary the rate or character of mixing, to vary the rate of cleaning of castings, to vary the rate of tumbling, or to vary the conveying and tumbling action between the material and the supporting surface of the container.
The aforesaid US-A-3793780 further generally discloses a vibratory apparatus for separating foreign matter from castings, comprising a hopper into which castings may be admitted and discharged, the hopper having a bottom surface for supporting the castings, the bottom surface being concave in cross-section and having an upstanding wall region, vibration imparting means for directing vibratory forces to the hopper to separate foreign matter from the castings, the vibration imparting means comprising at least one motor having a shaft which carries eccentric weight means thereon, and means for directing foreign matter separated from the castings away from the hopper.
More particularly, a tipped, U-shaped hopper is provided and the vibration imparting means comprises independently operable, vibratory imparting mechanisms associated with each leg of the hopper. Operation of the vibratory imparting mechanisms is coordinated to move the castings towards a dead zone for tumbling and shot treating and away from the dead zone upon completion of the tumbling and treating operations to discharge the castings.
The principal difficulty with this type of equipment is that the vibration is not imparted continuously during the separating operation. Rather, the vibration imparting mechanisms are stopped and started, requiring monitoring and coordination. Aside from the above, the intermittent operation of the vibration imparting mechanisms result in possible excessive wear thereon.
Another drawback with the equipment is that some intermixing of the castings with the shot, the separated sand and the scale occurs. Sand and shot tend to remain in the hopper with the castings as the castings are agitated and transported for discharge. The discharged castings therefore can retain some of the shot, sand and scale. In the event that engine blocks or the like are cast, complete removal of sand, scale and shot and other foreign matter is absolutely essential. Thus, a subsequent cleaning operation would have to be performed in the cast parts.
In accordance with a further aspect of the invention as claimed, the aforesaid generally disclosed vibratory apparatus for separating foreign matter from castings is characterised in that the hopper has an inlet for admitting castings to the hopper and an outlet through which the castings are discharged from the hopper which outlet is spaced from the inlet in a first longitudinal direction, the motor shaft lies in a plane extending transverse to the first direction, resilient means are mounted between the vibration imparting means and the hopper for resiliently mounting the vibration imparting means to the hopper for directing vibratory forces thereto to cause castings supported on the bottom surface to move in the first direction towards the hopper outlet and at the same time to follow the concave contour thereof and move up its upstanding wall region until under gravitational influence the castings tumble over themselves thereby following a substantially helical path between the hopper inlet and outlet, and the foreign matter directing means direct foreign matter separated from the castings, as they follow the substantially helical path, away from the hopper, whereby the castings can be continuously moved between the hopper inlet and outlet and foreign matter can be continuously separated from the castings and directed away from the hopper.
Thereby, this aspect of the invention is advantageous in that the hopper is vibrated without interruption to advance castings continuously in a path between its inlet and outlet ends. Simultaneously, shot, sand, scale and other foreign matter are discharged from the hopper separately from the castings. A preliminary shake-out of the castings may take place prior to the introduction of the castings into the hopper and subsequent abrasive removal operation may take place separately upon the castings being discharged from the hopper. Shot can be propelled at the castings in the hopper to enhance dislodging of foreign matter therefrom. Castings leaving the system are effectively cleaned of all foreign matter, i.e. shot, sand and/or scale.
Attention is also directed to US-A-3157004 of which the inventor is again Albert Musschoot. This patent concerns obtaining an improved finish on cast or moulded parts by adding a vibratory motion to the tumbling apparatus, the system being developed in the early 1960's. Specifically, the tumbling apparatus using a U-shaped tub mounted on trunnions. Vibratory force was applied directly to the U-shaped tub and passed through the centre of gravity of the tub. When the tub was tilted about the trunnions, the vibratory force was used to discharge the media and parts from the tub.
In order that the present invention may be well understood there will now be described two embodiments thereof, given by way of example, reference being made to the accompanying drawings, in which:

Figure 1 is a plan view showing schematically an overall system for separating foreign matter from castings with the present invention incorporated;
Figure 2 is a side elevation view of a continuous hopper section in the system of Figure 1;
Figure 3 is an enlarged sectional view of the hopper taken along line 2-2 of Figure 1;
Figure 4 is an end view of one preferred form of a vibratory tumbling machine with some parts shown in cross-section and some parts shown in phantom;
Figure 5 is an elevation view of the machine of Figure 4 as viewed from the right in Figure 4;
Figure 6 is a view like Figure 4 but with a difference in the line of application of the vibratory force;
Figure 7 is a view of one form of deck for mounting the vibration generator of Figure 4 showing alternative positions of the deck;
Figure 8 is a view similar to Figure 6 showing a modification of the preferred vibratory tumbling machine;
Figure 9 is a view like Figure 5 of the modified preferred vibratory tumbling machine;
Figure 10 is a copy of a chart of the paths of movement of material in the machine of Figure 4 in operation;
Figure 11 is a copy of a chart of the paths of movement of material in the machine of Figure 8 in operation; and
Figure 12 is a cross-sectional view of a cylindrical deflector with openings or ports therethrough.

Referring first to Figure 1, a depiction of an overall system appears for loading castings into a primary separation structure 10, in which foreign matter such as scale and/or sand is dislodged from the castings, and unloading of the castings upon treatment in the primary separation structure 10 for subsequent cleaning occurs. A high frequency shake-out structure is indicated at 12 and is responsible for initial breakup of mould bound castings. The castings, after initial breakup of the moulds occurs, are directed to an inlet 14 for the separation structure 10 and are operated upon in a manner that will be described in detail below. The castings discharge from the separation structure 10 at an outlet 16 and are directed to a casting roll- over, abrasive removal station 18 whereat final casting cleaning is carried out.
The details of the primary separation structure, wherein the present invention resides, are shown in Figures 2 and 3. The primary separation structure has a hopper 20 with a bottom surface 22 for supporting the castings as they travel between the inlet and outlet ends. A typical casting 24 is shown in Figure 3 and may be, for example, an engine block. The bottom surface 22 is supported in an inclined attitude as shown in Figure 2 and slopes downwardly from the inlet end 14 towards the outlet end 16. The hopper 20 has attached, reinforced end walls 26, 28 with bottom surfaces 30 borne upon by isolation springs 32 interposed between the surfaces 30 and the system support surface 34. Spaced longitudinally directed tubes 35 are fitted between the facing surfaces 37 of the end walls 26, 28. Coaxial tie rods 39, internally of the tubes, draw the end walls 26, 28 towards each other and against the tube ends so that a unitary assembly results. The hopper 20 is fixed captively between the end walls 26, 28.
The bottom surface 22 of the hopper has a substantially U-shaped configuration in cross-section, as seen clearly in Figure 3, and is skewed with respect to the vertical so as to define a substantially horizontal leg 36 and a vertical leg 38 having an upstanding wail surface 40. The hopper 20 is sealed by a removable hood 42 between the end walls 26, 28. The end walls 26, 28 have curved cutouts 44 (one shown) defining passages for the castings at the inlet 14 and the outlet 16.
Vibration imparting structure for the hopper 20 comprises motors 46 mounted resiliently, as by coil springs 47, to an inclined exciting wall 48 carried by the hopper 20 midway between the end walls 26, 28. The disclosed arrangement is a two mass vibratory system. An exciting mass at 50 comprises the motors 46 and an associated mounting base 52. The second mass comprises the hopper 20, the end walls 26, 28, the hood 42 and a discharge section 54 which diverts separated foreign matter. Each motor 46 has a shaft 56 offset from the vertical and substantially perpendicular to the line of movement of the castings between the hopper outlet and inlet. Each shaft 56 carries a pair of eccentric weights 58 at its ends. As the shafts 56 rotate, the hopper 20 is caused to move reciprocatively substantially along a line 60 so that conveyance of the castings 24 towards the right (Figure 2) occurs.
The path of an exemplary casting 24 will now be described. As the motors 46 are activated, the casting follows the curvature of the bottom surface 22 and in effect begins climbing the upstanding wall 38. As the casting 24 moves vertically, gravitational forces on the casting due to the incline of the bottom surface 22 at the same time cause the casting 25 to vibrate towards the outlet 16. The casting 25 climbs until it ultimately tumbles over itself. As this operation continues, the casting 25 traces a substantially helical path. As the casting follows the described path, the foreign matter such as the scale and mould material tends to progressively dislodge.
Separation of foreign matter may be assisted by propelling shot towards the castings progressing through the structure 10 at a shot treatment station 61. A conventional wheel 62 directs shot centrifugally through an opening 64 in the hood 42. The impinging shot jolts the castings to effect separation of foreign matter that might otherwise not occur through tumbling alone.
Structure may be provided for diverting foreign matter, separated from the castings in the hopper, away from the hopper. To accomplish this end, openings 66 are provided in the wall of the hopper. A shelf 68 resides at the openings 66 and is fed by a ramp 70 inclined downwardly away from the hopper opening 66. The vibration of the hopper tends to shift the separated foreign matter towards the shelf. The ramp and shelf vibrate in conjunction with the hopper so that the foreign matter tends to move in the direction of an arrow 72 by the combined effect of gravity and the vibratory conveying force imparted by the motor 46.
The shelf 68 resides in a chamber 71 above a floor 74 at the bottom of the chamber and has openings 76 to permit passage of a first size material which drops to the floor 74 and moves in the direction of an arrow 78 to a point of collection. Material unable to pass through the shelf discharges from the upper portion of the chamber separately from the smaller size particles. By separating the foreign matter as the castings move along the length of the separating structure, the foreign matter does not find its way back into chambers and/or crevices defined by the castings or reattach to the castings. Upon exiting the separation structure, the castings are rolled over and any remaining foreign matter separated at the station 18.
In an alternative and preferred form of the invention shown in Figures 4 - 6, a tumbling apparatus for mixing, cleaning, and/or shake out of parts is designated by numeral 110 and comprises a container 112 which in the illustrated form is a cylindrical drum and a vibration generator 114. The container 112 could be an open top member, an oval member or any desired shaped member as long as it has a horizontal axis. The container 112 is attached at each end to end plates 116 of a frame 118. In addition to the end plates 116, the frame has a bottom plate 120 connected to the end plates with corner reinforcing gussets 122 extending between the container, an end plate and the bottom plate for supporting the container 112. Gussets 124 extend between a flange 126 and the end plates in the vicinity of the corners of the machine to provide reinforced pads at the corners. The machine is resiliently supported on a foundation or base 128 by means of springs 130 attached to the pads on the flanges 126 and to the foundation. The springs 130 may be coil springs, as shown, or may be air springs or the like.
The container 112 has an inlet port 132 near the high point of the container at one end portion and is comprised of a flanged opening 134 having a funnel shaped hopper 136. The inlet port 132 could be through the high part of the end plate 116 just as well. An outlet port 138 is formed through the side wall of the container upward of the low point of the container and at the opposite end of the container from the inlet port. The outlet port 138 can be opened or closed, but when opened, has a platform 140 over which the discharged parts and/or media flows. A conveyor 142 communicates with the outlet port for conveying discharged parts and/or media away from the machine. The discharge or outlet port 138 could be through the low point of the cylinder of the container for certain applications. It will be noted in Figure 5 that the horizontal axis 139 of the container angles a few degrees from the horizontal so that the outlet end of the container is lower than the inlet end. This accommodates flow of the material through the container as the tumbling, mixing, polishing and/or shake-out is taking place.
A bracket 144 includes a pair of spaced apart mounting supports 146 affixed to the container on one side of the vertical axis of the container. The ends of the supports 146 spaced from the container have a substantially horizontal edge 148 with an aperture 150 through an end portion of each support in horizontal alignment with each other. A horizontal axis 152 connecting the centres of the two apertures 150 is parallel to the horizontal axis 139 of the container. As shown in Figure 1, a line 154 drawn through the centre (at the horizontal axis 139) of the container 112 and the centre (horizontal axis 152) of the apertures 150 of the bracket 144 forms an angle A to a vertical axis 156 of the machine. As shown, the angle A between the line 154 and the vertical axis 156 of the container is approximately 45°. The bracket 144 also has a mounting deck 158 between the supports 146 and, as shown, the deck is pivotally mounted to the supports 146 by pivot pins 160 passing through apertures 162 in depending flanges 164 on the deck and through the apertures 150 in the supports 146. The deck 158 is locked in position relative to the supports 146 by means of a pair of bolts 166 passing through arcuate slots 168 in the supports 146. When the bolts 166 are tightened down, the deck 158 is locked in place on the supports on the container. For the purposes of Figure 1, the surface of the deck 158 lies in a plane perpendicular to the vertical axis 156 and parallel to the horizontal axis 152 of the pivot pins 160.
The vibration generator 114 comprises a support plate 169 resiliently mounted on the deck 158 of the bracket 144 by a plurality of springs 170. A motor 172 is mounted on the support plate 169 with the axis of a double ended drive shaft 174 lying substantially parallel to the longitudinal axis 139 of the container. Eccentric weights 176 are mounted on each end of the double ended shaft and are encased in covers 178. Variable force vibration generators such as the types shown in our US-A-4495826 and US-A-3358815 may be substituted for the eccentric weights 176 on each end of the shaft 174. As illustrated in Figures 4-6, the linear vibratory forces are generated by a two mass system, the motor 172, the plate 169 and the weights 176 being one mass, and the container 112, the bracket 144 and the frame 118 being the second mass. The vibration generator 114 as shown in Figure 4 has an axis 180 which is vertical and intersects the axis 154 of the pivot pins 160 and is perpendicular to the support surface or foundation 128.
Operation of the vibration generator 114 will produce vibratory forces 182 (illustrated generally by the double ended arrow) along a linear path 180. As shown, the path 180 and the linear forces 182 pass exteriorly of the container 112. The path 180 may intersect the container, but it should not go through the centre of gravity of the container.
When the apparatus shown in Figures 4 and 5 is operating and the vibration generator is producing linear vibratory forces along the axis 182, the container 112 will move in an arcuate path, basically segments of a circle, having a centre of rotation offset from the centre of the container and located at a point R. The material within the container in contact with or close to the inside surface will be moved along an angle of attack with respect to the inside surface of the container. The angle of attack is arcuate, basically a segment of a circle centred at R.
The centre of rotation R is either a point or a small closed figure such as a small circle or ellipse which for all practice purposes may be considered to be a point. The point R will lie along a line passing through the centre of gravity CG of the container and intersecting the linear line of force 182 at an angle of 90°. That intersection is on one side of the centre of gravity CG and the point R will be on the other side of the centre of gravity.
The centre of rotation R should be offset from the centre of the cylindrical container. If the container is not cylindrical but has a curved concave material supporting surface, the centre of rotation R should be offset from the centres of circles osculating said concave surface. ^*
To illustrate the concept, see Figure 10, a sheet of paper was affixed to one end of the container 112 and the vibration generator 114 was energized and tuned to resonance, thereby producing a linear force 182 along the axis 180. A stylus carried by an immovably fixed support on the foundation or stationary surface 128 was engaged with the paper at various points on the end plate in alignment with the surface of the container. A tracing of the movement of the container, indicated at 184, was subscribed on the paper by the stylus. The stylus was spotted against the paper and the container, a multiplicity of times in the vicinity of the centre of rotation until the point R was located; that is, the point about which the container rotated. By drawing radii 186 from the point R to the tracings, it was found that the tracing segments of a circle are centred at R.
The movements 184 along the bottom (or low point) of the container are directed inward into the mass with an angle of attack to produce conveying action of the media and parts. The movements 184 acting on the working media 188 and/or parts 190 in the container provide a vigorous and effective counter-clockwise path of motion to the media and parts in the container. The parts and media are conveyed up the inner surface of the container adjacent the vibration generator before falling back into the container. The vigorous circulatory motion provides improved tumbling of the parts in the media to increase the speed and effectiveness of the mixing in the container and of the burnishing and polishing of the parts. Due to the slight tilt to the axis 139 of the container 112 to the horizontal, the parts, as they are tumbled, will migrate from the inlet end to the discharge end of the container. In the alternative, with the axis 139 of the container horizontal, the amount of material added at the inlet 136 will determine the amount of material discharged at the outlet port 138. The outlet port 138 can be open or closed (shown open in Figure 4). When the outlet port 138 is open, the media and parts will exit the container on the ramp 140 at the upper portion of the circulatory path. The ramp 140 can be foraminous to permit the media to fall down into a collection receptacle prior to being returned to the container or, as shown, the parts and media are delivered on to the conveyor 142 and will be conveyed to the next processing station. The inner surface 183 of the container may be coated or lined with a material having a particular coefficient of friction to aid in the conveying action and to improve the tumbling of the parts. The lining acts as a wear surface and can be replaced when worn.
The character of movement of the container and handling of the material within the container may be altered or modified by moving the location of the centre of rotation R. The position of R will change if the direction of the linear vibratory forces change. Similarly, the position of R will change if the centre of gravity CG is changed such as, for example, by adding weights to the container. Incidentally, when the centre of gravity of the container is referred to, it includes not only the container 112 but all parts attached to the container
^* Webster's New Collegiate Dictionary 1975 defines an osculating circle as "a circle whose centre lies on the concave side of a curve on the normal to a given point of the curve and whose radius is equal to the radius at that point". between the springs 130 and the springs 170.
The effects of changing the direction 182 of the vibratory forces is illustrated in Figure 7. In this case the bolts 166 were loosened and the vibration generator 114 was tilted to incline the line of vibratory forces 182 some 5° from vertical and the line of vibratory forces angled toward the container. Inasmuch as the centre of rotation R lies on a line normal to the line of force and passing through the centre of gravity CG, R will assume a new position as shown in Figure 7. With R in a new position, points on the inner surface of the container will move in an arcuate path or segments of a circle centred at the new location of R. This imparts a vibratory conveying movement to the material adjacent or in contact with such point to move along such paths thereby providing a different character of movement of the mass of material inside the container. The effect that will be first noted with the relocation of R is the change in the slope of the material within the container.
A valuable and perhaps surprising characteristic in the operation of the apparatus shown when used as a vibrating tumbling apparatus where parts and a media are placed within the container is that the parts themselves will remain immersed in the media. This is of importance not only in enhancing the cleaning and burnishing effect of the operation but also prevents damage to the parts being treated which would occur if the parts surfaced and vibrated directly against the interior surfaces of the container and against each other.
Figures 8 and 9 show a modified tumbler apparatus 110 with the axis of the vibration generator 114 tilted to a 95° angle as in Figure 7. A baffle or deflector 192 is selectively located in the container with Figure 11 showing the modified flow pattern and forces acting on the material when the deflector 192 is added to the system. All of the structural elements of Figure 8 that are the same as the structural elements of Figure 4 will bear the same reference numerals. The line of vibrational force 182 is external of the container. The instantaneous centre of rotation R will be located at point R so that the movements 184 acting on the material in the drum will subscribe the appropriate angle of attack with the surface of the container.
The baffle 192, which in Figures 8 and 9 is cylindrical but which could be square, rectangular, tear drop shape or the like in cross section, extends from end to end of the container 112 between the end walls 116 and can be adjusted to any desired position using appropriate means. The baffle or deflector 192 deflects a portion of the media over the outside of the deflector changing the pattern of flow of media and parts 190 in the container. The baffle can be set so that only media goes over the deflector with the parts remaining submerged in the media. The tumbling and mixing of the media was more pronounced and the media and parts climbed higher in the container before the media cascaded back down over the deflector. With the deflector 192 adjusted so that it was closer to the container walls, the parts were sometimes exposed on the surface of the media but once the parts 190 tumbled over the deflector, they re-immersed in the media thereby minimizing scratching and bumping between the parts.
The deflector 192 may be provided with openings, or ports 193, see Figure 12, through which hot air for heating the media or cold air for cooling the media can be piped. Burner jets could be provided in the deflector with the nozzles pointing into the media. When ignited, the jets would burn off carbonaceous particles on sand being processed and cleaned.
The line of force 182 along the axis 180 of the vibration generator passes exterior of the container or intersects the container, but does not pass through the centre of gravity of the container.
Although the improved tumbling apparatus has been described as employing a two mass system, such as shown at 114 in Figure 4, the apparatus does operate effectively with any linear vibratory force system mounted directly on the container and producing a linear line of force. The vibration generator 114 is shown upward and to the right of the container 112. It is to be understood that the vibration generator may be located at other positions as long as the line of force 182 is substantially offset from the centre of gravity of the apparatus and so long as the centre of rotation is not on the vertical centreline of the container 112. Thus, as all points on the material supporting surface of the container are moved in segments or paths of different circles having a common centre at R, such segments or paths are not parallel.

Claims

1. A vibratory apparatus comprising a container (112) having a material supporting surface, mounting means (130) for resiliently mounting the container (112) for unconstrained vibratory movement relative to a mounting surface (128), and vibration generator means (114) mounted on the container (112), characterised in that the material supporting surface is concavely curved in cross-section with respect to the interior of the container (112) and is either generated about an axis (139) when constituting a circular arc or is generated about the centres of circles osculating the concavely curved surface, the vibration generator means (114) is mounted on the container (112) offset from the axis (139) or osculating circles centres and generating vibratory forces (182) along a linear path (180) offset from the axis (139) or from the osculating circles centres, the vibration generator means (114) and the container (112) having a centre of gravity (CG) offset from the axis (139) or from the osculating circles centres of the container (112), the vibration generator means (114) and the linear path (180) of vibratory forces (182) being on the same side of the centre of gravity (CG), the vibratory forces (182) vibrating each point on the material supporting surface along segments of circles which do not conform to the curvature of the curved material supporting surface at the related point, each circle segment having a centre (R) of rotation which lies at a position spaced from the axis (139) or from the osculating circles centres and from the centre of gravity (CG) and on the opposite side of the axis (139) or the osculating circles centres of the container (112) from the linear path (180) of vibration forces (182).

2. A vibratory apparatus as claimed in claim 1, wherein the container (112) is rigidly mounted on a frame (118) and wherein the mounting means (130) for resiliently mounting the container (112) is comprised of isolation springs (130) between the frame (118) and the mounting surface (128).

3. A vibratory apparatus as claimed in claim 1 or claim 2, wherein the axis (139) lies substantially horizontal relative to the mounting surface (128) and wherein means are provided for changing the angle of tilt of the container (112) relative to the mounting surface (128).

4. A vibratory apparatus as claimed in any of claims 1 to 3, wherein a bracket (144) is mounted on the container (112) and wherein the vibration generator means (114) comprises a vibration generator (114) and a support plate (169) upon which the vibration generator (114) is mounted, the vibration generator (114) and the support plate (169) being resiliently mounted on the bracket (144).

5. A vibratory apparatus as claimed in any of claims 1 to 3, wherein the vibration generator means (114) comprises a support plate (169), vibratory force transmitting springs (170) connecting the support plate (169) to a bracket (144) on the container (112), a motor (172) mounted on the support plate (169), and eccentric weights (176) driven by the motor (172) for producing the vibratory forces (182) along the linear path (180).

6. A vibratory apparatus as claimed in Claim 4 or claim 5, wherein the vibration generator means (114) is adjustably mounted on the bracket (144) whereby the direction of the linear path (180) of vibratory forces (182) of the vibration generator means (114) can be changed.

7. A vibratory apparatus as claimed in any of claims 1 to 5, wherein means (150, 160, 162, 166, 168) are provided for adjusting the vibration generator means (114) relative to the container (112) for changing the direction of the linear path (180) of the vibratory forces (182) which in turn changes the location of the centre of rotation (R) and changes the vibratory forces (182) vibrating each point on the material supporting surface.

8. A vibratory apparatus as claimed in any of claims 1 to 7, wherein the vibration generating means (114) includes a variable force vibration generator (114) for varying the vibratory forces (182) acting on the container (112).

9. A vibratory apparatus as claimed in any of claims 1 to 8, wherein deflector means (192) is disposed in the container (112) and is submerged in the media (188), the deflector means (192) changing the path of flow of media (188) and parts (190) being tumbled in the container (112).

10. A vibratory apparatus as claimed in claim 9, wherein the deflector means (192) lies parallel to the axis (139) of the container (112), and including means for passing air through the deflector means (192) and into the media (188) and parts (190) for modifying the condition of the media (188) and parts (190).

11. A vibratory apparatus as claimed in any of the preceding claims, wherein the centre (R) of rotation lies on a line perpendicular to the linear path (180) and passing through the centre of gravity (CG).

12. A method of operating a resiliently supported vibratory material handling container (112) which comprises using vibration generator means (114) to generate vibratory forces (182) along a linear path (180) and transmit the forces (182) to the container (112) with the linear path (180) displaced to one side of the centre of gravity (CG) of the container (112) to cause the container (112) to vibrate, characterised in that the container (112) has a material supporting surface which is concavely curved in cross-section with respect to the interior of the container (112) and is either generated about an axis (139) when constituting a circular arc or is generated about the centres of circles osculating the concavely curved surface, the linear path (180) along which the vibratory forces (182) are generated being offset from the axis (139) or from the osculating circles centres, the vibration generator means (114) and the container (112) having a centre of gravity (CG) offset from the axis (139) or from the osculating circles centres of the container (112), the vibration generator means (114) and the linear path (182) of vibratory forces (182) being on the same side of the centre of gravity (CG), the vibratory forces (182) vibrating each point on the concavely curved material supporting surface along segments of circles which do not conform to the curvature of the concavely curved material supporting surface at the related point, each circle segment having a centre (R) of rotation lying at a position spaced from the axis (139) or from the osculating circles centres and from the centre of gravity (CG) and on the opposite side of the axis (139) or the osculating circles centres of the container (112) from the linear path (180) of vibratory forces (182).

13. A vibratory apparatus for separating foreign matter from castings, comprising a hopper (20) into which castings (24) may be admitted and discharged, the hopper (20) having a bottom surface (22) for supporting the castings (24), the bottom surface (22) being concave in cross-section and having an upstanding wall region (40), vibration imparting means (46) for directing vibratory forces to the hopper (20) to separate foreign matter from the castings (24) , the vibration imparting means (46) comprising at least one motor (46) having a shaft (56) which carries eccentric weight means (58) thereon, and means (66) for directing foreign matter separated from the castings away from the hopper, characterised in that the hopper (20) has an inlet (14) for admitting castings (24) to the hopper and an outlet (16) through which the castings are discharged from the hopper which outlet is spaced from the inlet in a first longitudinal direction, the motor shaft (56) lies in a plane extending transverse to the first direction, resilient means (47) are mounted between the vibration imparting means and the hopper for resiliently mounting the vibration imparting means to the hopper for directing vibratory forces thereto to cause castings supported on the bottom surface to move in the first direction towards the hopper outlet and at the same time to follow the concave contour thereof and move up its upstanding wall region until under gravitational influence the castings tumble over themselves thereby following a substantially helical path between the hopper inlet and outlet, and the means (66) direct foreign matter separated from the castings, as they follow the substantially helical path, away from the hopper, whereby the castings can be continuously moved between the hopper inlet and outlet and foreign matter can be continuously separated from the castings and directed away from the hopper.

14. A vibratory apparatus as claimed in claim 13, wherein the bottom surface (22) of the hopper (20) is curved in cross-section and is integral with the upstanding wall region (40).

15. A vibratory apparatus as claimed in claim 14, wherein the bottom surface (22) is of substantially U-shaped configuration in cross-section with one leg (38) of the U defining the upstanding wall region (40) and the other leg (36) of the U being closer to the horizontal than said one leg.

16. A vibratory apparatus as claimed in claim 15, wherein the hopper (20) comprises an upper quadrant including said one leg (38) of the bottom surface (22) of the hopper and a lower quadrant including the other leg (36), the quadrants lying on opposite sides of a longitudinal plane of the hopper, the longitudinal plane lying substantially parallel to the transverse plane containing the motor shaft (56) of the vibration imparting means (46), and the vibration imparting means being mounted to the hopper to direct vibratory forces thereto in a direction substantially perpendicular to the longitudinal plane of the hopper and through the upper to the lower quadrant thereof.

17. A vibratory apparatus as claimed in any of claims 13 to 16, wherein the means (66) for directing foreign matter away from the hopper (20) comprises an opening (66) in the hopper and a ramp (70) at the opening inclined downwardly away from the hopper, the vibration imparting means (46) having a force component directing foreign matter towards the ramp.

18. A vibratory apparatus as claimed in claim 17, wherein the ramp (70) directs the foreign matter to a shelf (68) having openings (76) allowing passage therethrough of foreign matter of a first size.

19. A vibratory apparatus as claimed in any of claims 13 to 18 including a shot wheel (62) provided upon the hopper (20) upstream from the means (66) for directing the foreign matter away therefrom, the shot wheel propelling shot on to the castings (25) as they are conveyed from the inlet (14) to the outlet (16) of the hopper.