GB2625547A

GB2625547A - Gemstone holder

Info

Publication number: GB2625547A
Application number: GB2219220.7A
Authority: GB
Inventors: Suganthan Shan; Bodhinayake Sud; Felix James; Nikiforov Ivan
Original assignee: De Beers UK Ltd
Current assignee: De Beers UK Ltd
Priority date: 2022-12-20
Filing date: 2022-12-20
Publication date: 2024-06-26
Also published as: WO2024132765A1; GB202219220D0

Abstract

A reorientation assembly comprises at least two gripping members 110a, 110b, wherein the at least two gripping members are moveable with respect to each other. The at least two gripping members, when abutting each other, define an opening, the opening comprising a tapered constriction portion (114, figure 2a) and a gripping portion (112, figure 2a) the tapered constriction portion defining an opening tapered towards the gripping portion. In some embodiments, the device is used for reorientating a gemstone. There may be suction nozzle 120

Description

Gemstone Holder This application relates to the gripping, holding and orientation of objects, in particular small objects such as gemstones.

Background section

Reference is made to known methods for gripping or holding small objects and reorienting small objects. One basic example of a known method is the use of tweezers.

Statement of invention

In one aspect of the present invention there is provided a reorientation assembly, the assembly comprising: at least two gripping members, wherein the at least two gripping members are moveable with respect to each other; wherein the at least two gripping members, when abutting each other, define an opening, the opening comprising a tapered constriction portion and a gripping portion, the tapered constriction portion defining an opening tapered towards the gripping portion.

The gripping portion may define a throat. The gripping portion may comprise at least partially parallel walls.

The reorientation assembly may comprise a controller unit and a driving unit, together arranged to effect a reciprocating movement of one or more of the at least two gripping members.

The reorientation assembly may comprise a guide, defining a path to the opening. The guide may comprise at least one wall, which wall has an orientation with a substantially horizontal component during use. The guide may be attached to one of the at least two gripping members.

The reorientation assembly may further comprise a suction nozzle. The suction nozzle may comprise a surface with a plurality of openings, allowing gas flow into the nozzle or out of the nozzle. The surface may be at least partially substantially flat with a diameter of substantially 5mm, and comprises a plurality of openings with diameters in the range of 0.5mm to 0.6mm.

In use the guide may be arranged above the at least two gripping members, and the suction nozzle may be arranged below the at least two gripping members.

In another aspect there is provided a method of reorienting an object, the method comprising: receiving the object between at least two gripping members, moving the at least two gripping members with respect to each other while the object is received between the at least two gripping members; wherein the at least two gripping members, when abutting each other, define an opening, the opening comprising a tapered constriction portion and a gripping portion, the tapered constriction portion defining an opening tapered towards the gripping portion.

The moving may comprise reciprocating one or more of the at least two gripping members. The reciprocating may comprise oscillating one or more of the at least two gripping members away from and towards a longitudinal nozzle axis, thereby orientating the object vertically.

The method may comprise resting the object on a suction nozzle when the object is received between the at least two gripping members, and creating an air flow around the object and into the suction nozzle. The air flow may be created with a negative air pressure pump connected to the suction nozzle.

The method may further comprise feeding the object into the opening via a guide, said guide defining a path to the opening.

The object may be a gemstone.

Brief Description of the Figures

Some embodiments of the invention will now be described by way of example only and with reference to the accompanying drawings, in which: Figure 1 is a perspective view of a reorientation assembly; Figure 2a is a perspective view of a gripping member of the assembly of Figure 1; Figure 2b is a cross-sectional view of a gripping member; Figure 3a is a perspective view of a suction nozzle of the assembly if Figure 1; Figure 3b is a plan diagram of a suction nozzle; Figure 4 is a perspective view of a guide of the assembly of Figure 1; Figures 5a and 5b are side views of the assembly of Figure 1 in respective first and second positions; Figure 6 is a perspective view of a further gripping member; and Figure 7 is a flow diagram.

Description

Many instances are known in which it is desirable to measure one or more properties of an object. For example, properties can be determined to determine the object's value, quality, type, suitability or conformity to a standard. In the case of naturally occurring objects, such as gemstones, it can be rare to find examples which are completely free from any impurities. Most gemstones contain one or more inclusions, such as cracks or piques. The presence of inclusions can affect the overall quality of a gemstone.

In a rough i.e. uncut and/or unpolished gemstone, quality may influence what a manufacturer needs to do to the stone to get the maximum value from it. In a polished gemstone, the number, position and type of inclusions affect the value of the stone because they impact the way light travels through the stone, reducing the fire and brilliance of the polished gemstone and the overall attractiveness of its visual appearance. The gemstone cutter has to consider the consequence of removing part, or all, of any inclusion and the corresponding loss of weight and whether removal is economically feasible. A balance is usually reached between the finished size of the cut gemstone and the cut gemstone's final clarity grade.

In order to accurately identify possible inclusions in a rough gemstone, it may be desirable to obtain multiple images of the stone from different perspectives. In order to obtain one or more images of the stone, it can be mounted and rotated through 360 degrees, for example, or held in place while one or more imaging devices rotate around the stone. Under these circumstances, accurate orientation of the object or stone can be very important.

Moreover, obtaining images of the object in its entirety can also be advantageous and therefore it is desirable to mount the object such that no part of the object is obstructed by the mount, thus avoiding the need to image the object in two or more positions.

Gemstones for measuring or sorting are often provided in a batch. Therefore, throughput, speed and reliability of mounting and imaging is also a consideration. In particular, a batch or parcel of rough gemstones may comprise hundreds of very small stones, sometimes called "melee", of varying shapes. When handling such a variety of shapes, challenges such as avoiding stone wobble, mounting flat stones upright, determining a stone's rotational axis and automatic loading and/or mounting arise.

In addition, the handling of small objects, such as gemstones, requires technological solutions adapted to the scale of the objects. The present technology has been developed for the use with gemstones in particular, which have specific physical characteristics. The size of gemstones is generally in the range of a few millimetres to over a centimetre. The inventors have appreciated that the physical behaviour, in particular movement, of objects when handled by mechanical devices is determined by the dimensionless parameters in nonlinear differential equations. The equations include basic physical dimensions such as momentum, gravity, mass, air density, length and hardness of the object and hardness of the parts of the device in contact with the object. One example of a dimensionless parameter is the Reynolds number. The Reynolds number determines the pattern of fluid or gas flow around an object. When scaling objects, the physical behaviour will remain similar if the dimensionless numbers do not change. This phenomenon gives rise to the known concept of dynamic similitude. This concept is used in wind tunnels, where gas dynamics around large objects such as aeroplane wings can be observed in a scale model of the wings, as long as other parameters such as wind speed are adapted accordingly to keep the dimensionless parameters the same. Gas flow around small objects will be discussed in more detail below.

It will therefore be clear to the skilled person that a device suitable for reorienting large objects, such as glass bottles in a recycling plant, is not suitable for reorienting small objects, such as gemstones. Further, providing simply a smaller version of the device for reorienting large objects will not be suitable for use with small objects, because the dimensionless parameters, and thereby the physical behaviour, will change without adapting further.

Furthermore, some phenomena only occur in the domain of small objects, without occurring for large objects. One example is the electrostatic force between a gemstone and a larger surface near the gemstone. The electrostatic force can cause the gemstone to "stick" to the larger surface because the electrostatic force can exceed the gravitational force. For larger objects, the 'sticking' will not occur because the electrostatic forces are negligible when compared to the gravitational force.

In other words, the inventors have developed an assembly suitable for use with small objects, in particular gemstones, and have found that devices suitable for use with much larger objects cannot be adapted or used in any meaningful way for the same purpose.

Described herein with reference to Figures 1 to 7 is a reorientation assembly and a method of reorienting an object. While the assembly and method are described herein with specific reference to gemstones, it will be appreciated that the following may equally apply to other small objects, such as seeds, electronic components, fixings, pharmaceuticals, etc. In one embodiment, the reorientation assembly comprises at least two gripping members, wherein the at least two gripping members are moveable with respect to each other. The at least two gripping members, when abutting or converged with each other, define an opening, the opening comprising a tapered constriction portion and a gripping portion, the tapered constriction portion defining an opening tapered towards the gripping portion.

In one embodiment, a method of reorienting an object comprises receiving the object between at least two gripping members, moving the at least two gripping members with respect to each other while the object is received between the at least two gripping members. The at least two gripping members, when abutting each other, define an opening, the opening comprising a tapered constriction portion and a gripping portion, the tapered constriction portion defining an opening tapered towards the gripping portion.

An embodiment of the reorientation assembly discussed above will now be described with reference to Figure 1. In this embodiment, two gripping members are provided, but the inventive concept is not limited thereto. An assembly with three gripping members may be provided, for example. The gripping members may be referred to as cones, or cups. When in an abutted or converged position, the gripping members of this embodiment form a funnel, or cone shape.

Figure 1 illustrates the reorientation assembly 100. The reorientation assembly comprises two -first and second -gripping members 110a, 110b, shown abutting one another, and a suction nozzle 120. The embodiment of Figure 1 also includes a guide 130 and a track 140, and a controller unit and a driving unit, not shown here, arranged to effect a reciprocating or oscillating movement of one or more of the gripping members.

The controller unit comprises a processor, not shown here.

Figure 2a illustrates the first gripping member 110a of Figure 1 in more detail. It will be appreciated that the second gripping member, not shown here, has a complementary shape. The first gripping member 110a defines a substantially cone-shaped interior, comprising a tapered constriction portion 114 and a gripping portion 112. The tapered constriction portion 114 defines an opening tapered towards the gripping portion 112. The gripping portion 112 comprises at least partially parallel walls. The gripping portion 112 further comprises a portion with walls slightly tapered to the parallel walls.

Figure 2b illustrates example dimensions used to create the conical form or spline of a gripping member, such as the gripping member shown in Figure 2a. As shown, in this example, a guide angle at the top of the spline -which may be referred to as a tapered constriction portion -starts from an approximately 34mm diameter with a starting taper of approximately 13 degrees. The spline converges to a minimum diameter of 6mm at the bottom section -which may be referred to as a gripping portion -of the gripping member and ends at a diameter of approximately 7mm, at a distance of approximately 3mm from the minimum 6mm cross section.

It will of course be appreciated that the dimensions and general arrangement illustrated in Figure 2b are provided as an example only, and that the inventive concept is not limited thereto.

Referring back to Figure 2a, in an embodiment, the first gripping member 110a comprises a substantially curved elongate socket, or slot, 116 and a corresponding curved, elongate fin 118. When the first and second gripping members abut one another, the fin of the first gripping member is received by the slot of the second gripping member, and vice versa. Thus, when brought together into an abutting, contact or converged position, the first and second gripping members together form a cone, or funnel, having a central bore. The On use) respective upper tapered constructions portions of the first and second gripping members together define an opening in which a stone can be received. The (in use) lower respective gripping portions of the first and second gripping members together define a substantially annular portion defining a throat comprising at least partially parallel walls. Below the parallel walls, the constriction widens slightly again.

In an embodiment, the first and second gripping members define a cone or funnel having an interior with curved rather than flat surfaces. This curvature may prevent a stone from "sticking" to the cone interior as a result of electrostatic forces, as mentioned above.

Referring back to Figure 1, the assembly 100 comprises a suction nozzle 120. When the first 110a and second 110b gripping members are in an abutted or converged position, a surface of the suction nozzle 120 is positioned below the bore formed by the respective gripping portions of the first and second gripping members. The centre of the surface of the suction nozzle generally coincides with the central axis of the bore formed by the gripping members.

Figure 3a illustrates the suction nozzle 120 of Figure 1 in more detail. The suction nozzle comprises a lower body portion 122, connectable to a pressure source, such as a source of negative pressure, and an upper, substantially cylindrical, body portion 124. Here, the body portions 122, 124 are formed integrally, but could be formed as separate but connected units. The upper body portion terminates in a surface 126 with a plurality of openings, or apertures, 128, allowing air flow into the suction nozzle or out of the suction nozzle 120. In this embodiment, the surface is at least partially substantially flat with a diameter of substantially 5mm. In this embodiment, the plurality of openings 128 defined in the surface 126 are substantially circular and have diameters in the range of 0.5mm to 0.6mm.

Figure 3b illustrates further detail of an example suction nozzle, such as the suction nozzle of Figure 3a. As shown, the nozzle surface 126 defines a total of 13 apertures, or bores. A central aperture has a diameter of approximately 0.6mm; 8 outer apertures, arranged concentrically around the central aperture, each have diameters of approximately 0.6mm; and 4 inner apertures, arranged concentrically between the outer apertures and the central aperture, each have a diameter of approximately 0.5mm. A circle passing through the centres of the 8 outer apertures has a diameter of approximately 3mm, and a circle passing through the centres of the 4 inner apertures has a diameter of approximately 1.6mm. As illustrated in Figure 3b, an angle a between a line passing through a centre of one of the inner apertures, in particular though the centres of a pair of opposed inner apertures, and a horizontal passing the a centre of the central aperture is approximately 45 degrees i.e. the inner apertures are 90 degrees apart from centre to centre. An angle p between a line passing through a centre of one of the outer apertures, or in particular through the centres of a pair of outer apertures, and a horizontal passing through a centre of the central aperture is approximately 22.5 degrees, i.e. the outer apertures are 45 degrees apart from centre to centre.

In this specific example, a flow rate for each of the 0.5mm bores is approximately 0.14 m3/h and a flow rate for each of the 0.6mm bores is approximately 0.2 m3/h. Thus, a total flow rate for all 13 bores is (0.14 x 4) + (0.2 x 9) = 2.36m3/h.

It will be appreciated that the arrangement illustrated in Figures 3a and 3b is an example only, and that the inventive concept is not limited thereto. A specific combination of nozzle diameter and aperture diameter / position may be provided and optimised for a specific stone size and/or shape.

During the process of reorientation of the gemstone, suction -such as partial vacuum -is applied to create a flow of air into the nozzle. However, in some examples, a positive pressure is applied to create air flow in the opposite direction, for example to release the gemstone or to expel any debris stuck in one or more of the holes.

Although in the embodiment of Figure 3 the surface 126 is illustrated as having 13 openings in a specific arrangement, it will be appreciated that in other embodiments not shown here the surface is provided with more, or fewer, apertures or openings. Two or more of the openings may have different diameters to one another. Additionally, different arrangements of the openings may be envisaged according to the specific application. In a further embodiment, not shown here, the openings and nozzle surface are replaced by a mesh through which pressurised air or gas can flow.

The example arrangement illustrated in Figures 3a and 3b comprises five holes in cruciform shape, surrounded by 8 slightly larger holes arranged in a circle. The inventors have found through empirical methods, rather than through theoretical considerations, that this arrangement is particularly advantageous for keeping a gemstone in a stable and fixed orientation.

The suction nozzle 120 as illustrated in Figure 3a is configured, in use, to retain a gemstone on the nozzle surface 126 and to maintain the position and stability of the retained gemstone. It will be appreciated that only a single point of contact is required between the nozzle surface and the stone, and that therefore no part of the retained stone is obscured by the suction nozzle.

The provision of a cluster of openings 128 in the surface 126, as illustrated in Figure 3a, through which suction can be applied, assists in quickly settling the stone as it is dispensed onto the nozzle surface 126 and in preventing wobble or vibration of the stone once suction is applied.

Referring once more to Figure 1, the reorientation assembly 100 comprises a guide 130.

As illustrated, in this embodiment the guide 130 is attached to one of the gripping members 110a, and so is moveable therewith.

Figure 4 illustrates the guide 130 of Figure 1. The guide 130 defines a path P to the opening 150 formed by the first 110a and second 110b gripping members in an abutted or converged position. In this embodiment, the guide 130 comprises at least one wall 132 having an orientation with a substantially horizontal component, during use. An end of the guide 130 distal to the first 110a and second 110b gripping members defines an aperture 134 for receiving gemstones. An interior passageway of the guide, not shown, is configured to deliver a stone along the path P to the opening 150 formed by the first 110a and second 110b gripping members.

As illustrated in Figure 4, the guide 130 and therefore the path P has a curved or at least non-linear form, the function of which is to control delivery of a stone to the opening 150. For example, a curvature of the guide 130 may decelerate the stone as it travels along the path P towards the opening 150. Additionally, the guide 130 is configured such that a stone is delivered substantially to a centre of the opening 150.

With further reference to Figure 1, the assembly 100 comprises a linear track 140. In this embodiment, the track 140 is formed in two linear sections, each section attached to one of the gripping members.

Figures 5a and 5b illustrate the track 140 of Figure 1. As shown in Figure 5a, a first track section 140a is attached to the first gripping member 110a, and a second track section 140b is attached to the second gripping member 110b. In a first or "home" position, as shown in Figure 5a, the first 110a and second 110b gripping members are not abutted but are diverged or separated by a gap. In the second position, as shown in Figure 5b, the first track section 140a and the second track section 140b have been actuated to move towards one another, thereby closing the gap and bringing the first 110a and second 110b gripping members into abutment or convergence in a location above the suction nozzle 130.

In the embodiment of Figures 5a and 5b, movement of the first and second gripping members from the first position to the second position and back to the first position is carried out in a reciprocating motion. The first and second gripping members are driven by a controller and a driving unit, to oscillate away from and towards a longitudinal axis A of the suction nozzle in direction 0, which is substantially perpendicular to the nozzle axis A. This allows the suction nozzle to hold the stone whilst the oscillating motion of the gripping members nudges or judders the stone to orientate vertically relative to a plane formed by an upper surface of the suction nozzle.

It will be appreciated that the stone is oriented vertically through direct contact with the inner surfaces of the gripping members. These inner surfaces include, in some embodiments, the tapered constriction portion 114 and the gripping portion 112 of one or both of the gripping members, as best illustrated in Figure 2a. In other embodiments, only the gripping portion 112 or throat is used to orient the stone. As the gripping members oscillate relative to one another, a stone is nudged, pushed or jogged into vertical orientation, such that a rotational axis of the stone -once held on the suction nozzle -is substantially co-incident with a longitudinal axis of the nozzle and is substantially perpendicular to a plane formed by the nozzle's upper surface, comprising one or more apertures or the like.

In some embodiments, relative oscillation of the gripping members is carried out in steps. For example, one or both of the gripping members may be moved away from the nozzle axis by one step, then moved towards the nozzle axis by half a step, then away again by half a step, and so on. In this sense the oscillation can be periodic but not sinusoidal.

The oscillation may also be a-periodic. It will be appreciated that during such a step, lateral movement of a gripping member with respect to a longitudinal axis of the nozzle may only be in the order of millimetres, or less.

Once the stone has been oriented and retained upon the suction nozzle 130, the first 140a and second 140b track sections are actuated to return to the first or "home" position, as shown in Figure 5a, thereby separating the first 110a and second 110b gripping members attached thereto. This retraction of the track sections and gripping members allows for the stone mounted upon the suction nozzle to be imaged or otherwise measured without blocking the view by the gripping members. It may also allow the suction nozzle and stone mounted thereon to be moved, if desired. In one example, the stone is imaged in a first vertical position and then raised or lowered to a second, different vertical position in which further images can be captured, optionally under different lighting conditions. Since a longitudinal / rotational axis of the stone is known, as a result of the orientation, accurate images and/or other measurements may be obtained.

It will be appreciated that in other embodiments, not shown here, the gripping members may be actuated to slideably move along the track rather than moving with it. In further embodiments, the track is omitted and the gripping members are moved towards and away from each other using alternative actuation methods. It will be appreciated that in order to guide stone on to the suction nozzle, the gripping members are required to converge and to stay in a converged or abutted position until the stone is oriented, in contact with the nozzle, and held in suction. Once the stone is held in suction, the gripping members are actuated to diverge into a position in which the gripping members do not impede or obstruct the imaging device / camera field of view. Suitable actuation mechanisms for moving the gripping members and/or the track include: rack and pinion, piezo type, leadscrew type, and slideway type, but the inventive concept is not limited thereto. In some examples, these actuation mechanisms can be powered by a motor or a hydraulic, or pneumatic system.

Imaging or other measurement of the stone is carried out by a sensor, visible light detector, or the like. Once imaging / measurement of the stone is complete, the stone is dispensed from the suction nozzle into a dispense bin or other region of the apparatus, optionally according to the results of the imaging. In one embodiment, one or both of the gripping members are used to knock the stone off the nozzle via actuation of one or more of the track sections. In other embodiments, a positive air pressure -such as an air jet -is applied to the stone via the nozzle. Alternatively or additionally to the foregoing examples, an independent battering mechanism which will dislodge the stone from the nozzle, or an independent robotic pick and place mechanism, where the stone is picked from the nozzle and placed on to a desired location, can be used.

An example of operation of the reorientation assembly will now be described, referring again to Figures 1 to 7. In a first or "home" diverged position, the gripping members are separated by a gap, as shown in Figure 5a. A stone is then deposited or fed into the aperture of the guide, and follows a curved path provided by the guide towards the suction nozzle.

As the stone approaches the suction nozzle, the gripping members are actuated to move towards one another, into a second, abutting or converged position, thereby forming a funnel or cone having an opening for receiving the stone. The stone enters the opening and is funnelled by the tapered constriction portion into the throat formed by the gripping portions.

The gripping members oscillate with respect to one another, thereby bringing the stone into a vertical orientation with respect to the nozzle surface, through contact with the inner surfaces of the gripping members. During oscillation, suction is applied to the nozzle surface to retain the stone on the surface in the desired orientation. The gripping members are then actuated to retract during imaging of the stone, ultimately returning to the first "home" position, so that the next stone in the batch can be imaged and/or sorted.

Further detail of the activation of the oscillatory motion of the gripping members is provided below. The stone to be measured and/or imaged is held in a repository location -such as a hold gate -before being released to enter the aperture of the guide and from there into the opening formed by the abutted gripping members.

In this example, before releasing the stone, three steps take place, Si, S2, S3 as outlined below. In each case, operation of the gripping members and nozzle is co-ordinated by the controller, which is configured to receive and send signals from / to the various components of the assembly: Si. Confirmation of a vacant nozzle -this is done by image processing, where an image of the nozzle is taken to determine that the nozzle is empty; 52. Confirmation that the gripping members are in their convergent or abutted position. This is confirmed by obtaining motor signals from the motors that drive the gripping members, to calculate the actual position of the gripping members along their linear motion track.

S3. Once confirmations from Si and 52 have been obtained, the stone is released from the 'hold gate' and into the guide. Release of the stone is confirmed by a light curtain sensor through or past which the stone passes. The activation of the sensor triggers a time count that is used to coordinate the start of the oscillation of the gripping members.

In the above example, oscillation of the gripping members ends once the oscillating steps or in/out in sequence is complete and once the gripping members move to their "home" position, in which the gripping members are in the separated position i.e. furthest apart or fully divergent. In the diverged position, the gripping members are both away from the field of view for imaging the stone. The "home" position is confirmed by two light curtains that are triggered when the gripping members arrive at the fully divergent or first position.

As discussed above, the oscillatory motion of the gripping members with respect to one another brings or orients the stone into a vertical orientation with respect to a plane formed by the nozzle surface. In some embodiments, the size e.g. amplitude and/or frequency of the oscillations is varied according to one or more of: stone size, nozzle size, degree of taper of the gripping member's internal wall which funnels the stone in the 'upright' orientation.

Similarly, in some embodiments the profile of the gripping members and/or the oscillatory motion is optimised for a particular size of the stone. In this way, crushing or other damage to the stone is avoided. For example, the gripping members can move in steps in relation to one another, leaving a gap between the members; the number of oscillatory steps may be increased / decreased.

Although the suction from the nozzle and the oscillatory movement of the gripping members may be provided independently, with independent technical effects as described above, the inventors have found that the combination works particularly well for reorienting a gemstone in a predictable and stable manner.

It will be appreciated that while relative movement of each of the gripping members has been described, in some embodiments only one of the gripping members is moveable while the other gripping member is fixed. In some embodiments, the gripping members are retained in the abutting position without the use of an elongate fin and corresponding slot, as illustrated in Figure 2a; for example, retention may be provided magnetically or electrically, or by other mechanical components. Alternatively or additionally, the fin and corresponding slot may take a different form, as illustrated in Figure 6. Here, the elongate fin and corresponding slot are substantially straight-sided, rather than curved, as shown in Figure 2a.

In some embodiments, the gripping members are fabricated from metal, such as aluminium, stainless steel, titanium, or plastics, or a combination thereof. For example, gripping members could be 3D printed using PC-ABS plastic as a by-product of 'rapid prototyping'.

In some embodiments, a single controller unit comprising a processor is configured to control the operation of one or more of the gripping members, the track sections, the suction nozzle. It will be understood that, in some examples, the oscillatory motion of the gripping member(s) temporarily holds and orientates the stone. Where used, the fin and corresponding slot retain the stone when the gripping members are at their furthest distance from each other during the oscillatory motion. The fin and slot are designed to be in clearance so as to avoid the gripping members sticking together.

The method described in detail above is illustrated in Figure 7 for completeness. The method includes the steps of (Si) receiving the object between at least two gripping members, and (S2) moving the at least two gripping members with respect to each other while the object is received between the at least two gripping members. As described previously, the at least two gripping members, when abutting each other, define an opening, the opening comprising a tapered constriction portion and a gripping portion, the tapered constriction portion defining an opening tapered towards the gripping portion Features of the embodiments described herein may be combined or substituted without limitation, and the scope of the invention is defined in the claims that follow.

Claims

CLAIMS: 1. A reorientation assembly, the assembly comprising: at least two gripping members, wherein the at least two gripping members are moveable with respect to each other; wherein the at least two gripping members, when abutting each other, define an opening, the opening comprising a tapered constriction portion and a gripping portion, the tapered constriction portion defining an opening tapered towards the gripping portion.
2. The reorientation assembly of claim 1, wherein the gripping portion defines a throat.
3. The reorientation assembly of claim 1 or 2, wherein the gripping portion comprises at least partially parallel walls.
4. The reorientation assembly of any one of the preceding claims, further comprising a controller unit and a driving unit, together arranged to effect a reciprocating movement of one or more of the at least two gripping members.
5. The reorientation assembly of any one of the preceding claims, further comprising a guide, defining a path to the opening.
6. The reorientation assembly of claim 5, the guide comprising at least one wall, which wall has an orientation with a substantially horizontal component during use.
7. The reorientation assembly of claim 5 or 6, wherein the guide is attached to one of the at least two gripping members.
8. The reorientation assembly according to any one of the preceding claims, further comprising a suction nozzle.
9. The reorientation assembly according to claim 8, wherein the suction nozzle comprises a surface with a plurality of openings, allowing gas flow into the nozzle or out of the nozzle.
10. The reorientation assembly according to claim 9, wherein the surface is at least partially substantially flat with a diameter of substantially 5mm, and comprises a plurality of openings with diameters in the range of 0.5mm to 0.6mm.
11. The reorientation assembly according to any one of the preceding claims, comprising the guide according to any one of claims 5 to 7, and comprising the suction nozzle according to any one of claims 8 to 10, wherein in use the guide is arranged above the at least two gripping members, and wherein the suction nozzle is arranged below the at least two gripping members.
12. A method of reorienting an object, the method comprising: receiving the object between at least two gripping members, moving the at least two gripping members with respect to each other while the object is received between the at least two gripping members; wherein the at least two gripping members, when abutting each other, define an opening, the opening comprising a tapered constriction portion and a gripping portion, the tapered constriction portion defining an opening tapered towards the gripping portion.
13. The method of claim 12, wherein the moving comprises reciprocating one or more of the at least two gripping members.
14. The method of claim 13, wherein the reciprocating comprises oscillating one or more of the at least two gripping members away from and towards a longitudinal nozzle axis, thereby orientating the object vertically.
15. The method of claim 13 or 14, further comprising resting the object on a suction nozzle when the object is received between the at least two gripping members, and creating an air flow around the object and into the suction nozzle.
16. The method of claim 15, wherein the air flow is created with a negative air pressure pump connected to the suction nozzle.
17. The method of any one of claims 12 to 16, further comprising feeding the object into the opening via a guide, said guide defining a path to the opening.
18. The reorientation assembly or method of any preceding claim, wherein the object is a gemstone.