CN110325295B

CN110325295B - Dispensing apparatus

Info

Publication number: CN110325295B
Application number: CN201880014015.XA
Authority: CN
Inventors: 皮特·斯坦利·罗斯; 安德鲁·约翰·朴茨茅斯
Original assignee: De Beers UK Ltd
Current assignee: De Beers UK Ltd
Priority date: 2017-02-27
Filing date: 2018-02-26
Publication date: 2021-12-21
Anticipated expiration: 2038-02-26
Also published as: RU2019129289A; CN110325295A; RU2766099C2; WO2018154325A1; RU2019129289A3; EP3585527B1; EP3585527A1; GB201703134D0

Abstract

A dispensing apparatus for dispensing gemstones from a horizontally movable surface is provided. The apparatus comprises a wheel arranged to rotate about a horizontal axis above the surface. The wheel includes one or more teeth disposed about an outer periphery. The motor is configured to rotate the wheel and the sensor is configured to identify that one of the teeth is in a predetermined position to indicate that the wheel is in a home position. The runner is arranged to define a gap between the surface and the runner when the runner is in the home position. As the wheel rotates away from the home position, one of the teeth contacts the gemstone and pushes the gemstone away from the surface.

Description

Dispensing apparatus

Technical Field

The present invention relates to an apparatus for dispensing gemstones and a method of dispensing gemstones. In particular, although not exclusively, the invention relates to a method and apparatus for dispensing diamonds.

Background

Natural diamonds are stones from nature, including only diamonds formed during long-term geological processes. Synthetic diamond is artificial stone manufactured by industrial processes such as HPHT (high pressure high temperature) and CVD (chemical vapor deposition).

Synthetic diamonds have a wide range of industrial applications, but currently account for only a small portion of the gemstone industry and do not attract the high value associated with natural diamonds of similar color and quality. Synthetic diamonds can be relatively easily distinguished from natural diamonds when in an unpolished state, however, once polished and cut into gemstones, it may be more difficult to identify a gemstone as synthetic.

Advanced screening apparatus, e.g. Diamondsure^TMAnd DiamondView^TMAnd can be used for testing whether the stone is natural or synthetic. Typically, such screening involves the manner in which light is absorbed by a single diamond or light is extracted from a single diamondMeasurement of the manner in which the diamond emanates. It is also often desirable to screen a large number of smaller diamonds, including stone sometimes referred to as diamonds (melee). Small particles (melee) is a trade term that does not have a well-defined size range, but in practice is generally considered to refer to stone material that is less than about 0.2 carats (20 cents), and is generally (but not necessarily) greater than about 0.01 or 0.02 carats. In some cases, stone as small as 0.001 carat or even smaller may also be referred to as small particles (melee). Due to their small size, small particles of stone are often sold in small packets or lots. Since a packet may contain hundreds of stones, synthetic diamond and non-diamond materials may be mixed into natural stone.

The particles may be automatically sorted by various devices known in the art based on their measured attributes. For example, WO2012/146913 describes an apparatus in which gemstones are fed onto a rotatable disc through a hopper (hopper) and then oriented by passing through a pair of oscillating walls extending generally in the direction of the path of travel of the gemstones. Once oriented in its most stable state, the gemstones are removed one by one from the rotatable disk by a handling device (e.g., a vacuum wand mounted on a swing arm) and transported to a system for testing, measurement, or further processing. The processing means then dispenses the stones into the appropriate collection bins according to the test results.

Other dispensing and removal mechanisms are well known in the art, including air jets, flip blades, and push rods. However, many of these mechanisms have drawbacks. For example, after each dispensing, flipping the paddle and pusher bar requires time to reset, which effectively limits the degree of separation between the gems or components, i.e., the gems or components must be further separated to allow time for resetting. This limits the overall throughput of the device. Air jets do not require time to reset, but they are inaccurate, difficult to adjust, require baffles (baffles) that can cause parts to jam, and require wider parts separation if multiple parts are not to be sprayed simultaneously. The air jets also require a supply of compressed air, which can be inconvenient and unsuitable if the apparatus is to be operated outside a laboratory environment. Air jets also tend to introduce electrostatic charging (electrostatic charging) problems, which can create practical problems when dispensing smaller gemstones (e.g., small particles).

A challenge in selecting or designing a dispensing mechanism for a sorting apparatus (such as that described above) is to ensure that the speed at which gemstones or other discrete components are removed from the disc or belt does not become a limiting factor in the throughput of the apparatus. This is particularly important when the disk or belt is moving continuously throughout the sorting process.

Disclosure of Invention

According to a first aspect, there is provided herein a dispensing apparatus for dispensing a gemstone from a horizontally movable surface, the apparatus comprising: a wheel arranged to rotate about a horizontal axis above the surface and comprising one or more teeth disposed about its periphery; a motor configured to rotate the wheel; a sensor configured to identify when one of the teeth is in a predetermined position to indicate that the wheel is in a home position. The runner is arranged to define a gap between the surface and the runner when the runner is in the home position. The wheel is arranged such that when the wheel is rotated away from the home position, one of the teeth contacts the gemstone so as to push the gemstone away from the surface.

The wheel may be arranged such that one of the teeth is in contact with the horizontally movable surface when the wheel is rotated away from the home position and pushes the gemstone away from the surface.

The horizontal axis may be substantially parallel to the direction of travel of the surface.

The wheel may comprise a plurality of teeth arranged equiangularly around the periphery of the wheel. The home position may be defined as the position when the uppermost tooth is located at the predetermined position.

The wheel may comprise five equiangularly spaced teeth.

Each tooth may comprise a front portion and a rear portion, the front portion extending further from the centre of the wheel than the rear portion.

The wheel may comprise a closed cell foam.

The sensor may comprise a light curtain (light curve).

The dispensing apparatus may be configured to move the wheel to the home position after actuation of the motor.

The wheel may be configured to be driven in a first direction when the gemstone is dispensed from the horizontally movable surface, and wherein the wheel is configured to be driven in a second, opposite direction when the gemstone is directed to another region of the horizontally movable surface.

According to a second aspect, there is provided an apparatus for sorting gemstones comprising: one or more measurement locations, each measurement location comprising at least one measurement device configured to measure one or more properties of the gemstone; a horizontally movable surface for supporting the gemstone thereon and transporting the gemstone to the one or more measurement locations; one or more dispensing devices according to the first aspect above, the dispensing device being configured to dispense a gemstone from a horizontally movable surface according to a measured property of the gemstone.

The apparatus may include a controller configured to actuate the motor of each of the one or more dispensing apparatuses.

The apparatus may include a collection bin associated with each of the one or more distribution apparatuses.

The apparatus may comprise a plurality of dispensing devices arranged in an array such that the gemstone on the horizontally moveable surface passes successively through the wheels of the plurality of dispensing devices.

According to a third aspect, there is provided a method of dispensing a gemstone from a moving horizontal surface. The method comprises the following steps: the wheel is rotated about a horizontal axis above the surface, the wheel including one or more teeth disposed about its periphery, and the horizontal axis is positioned such that when the wheel is in the home position, there is a gap between the wheel and the surface. The method further comprises the following steps: identifying when one of the teeth is in a predetermined position to indicate that the wheel is in the home position, and stopping rotation of the wheel at that point. As the gemstone passes the wheel, the wheel is further rotated so that one of the teeth contacts the gemstone and pushes it away from the surface.

The horizontal axis may be positioned such that when the gemstone is further rotated past the wheel, one of the teeth is in contact with the moving horizontal surface as the gemstone is pushed away from the surface.

According to a fourth aspect, there is provided a method of sorting gemstones comprising: supporting the gemstone on a horizontal movable surface; transporting the gemstone with the surface to one or more measurement locations; measuring one or more properties of the gemstone at the one or more measurement locations; dispensing a gemstone from a horizontally moveable surface according to a measured property of the gemstone using one or more dispensing apparatuses according to the first aspect described above.

Drawings

Figure 1 shows an apparatus for dispensing gemstones;

FIG. 2a is a side view of the wheel of the apparatus of FIG. 1;

FIG. 2b is an enlarged view of a portion of FIG. 2 a;

figures 3 and 4 show the wheel of figure 1 in use;

FIG. 5 shows the apparatus of FIG. 1 in a gemstone sorting apparatus;

FIG. 6 is a front view of the sorting apparatus of FIG. 5;

FIG. 7 is a top view of the sorting apparatus of FIG. 5; and is

Figure 8 shows a method of dispensing gemstones.

Detailed Description

An apparatus 100 for dispensing a gemstone (e.g. a diamond) from a horizontally movable surface 103 will now be described with reference to fig. 1 to 4. The gemstone to be dispensed typically comprises a polished gemstone, both clear and fancy cut. A sorting apparatus 101 comprising one or more apparatus 100 for dispensing gemstones will be described with reference to figures 5 to 7. However, the use of the dispensing apparatus 100 described herein is not limited to this sorting apparatus 101. The dispensing apparatus 100 may also be used with other sorting devices, measuring devices, identification devices, etc. in which a gemstone or other discrete part presented continuously must be dispensed or removed therefrom. A method of dispensing a gemstone from a horizontally movable surface will be described with reference to fig. 8.

The dispensing apparatus 100 comprises a wheel 106, the wheel 106 being arranged to rotate about a horizontal axis a located above the horizontal movable surface 103. The horizontal axis a is substantially parallel to the direction of travel of the surface 103. The wheel 106 is in a plane substantially perpendicular to the direction of travel of the surface 103. The runner 106 includes one or

more teeth

104a, 104b disposed about its periphery. The apparatus 100 also includes a motor 116 configured to rotate the wheel 106. The sensor 112 is configured to identify that one of the

teeth

104a, 104b. The wheel 106 is arranged such that when the wheel 106 is in the home position, a gap is defined between the surface 103 and the wheel 106, and one of the

teeth

104a, 104b.

In the example shown in fig. 1-4, the wheel 106 has five outwardly facing

teeth

104a, 104b, 104c, 104d, 104e spaced around the outer circumference of the wheel 106. In other embodiments not shown here, fewer or more teeth may be provided. For example, one, two, three, four or more teeth may be provided. The

teeth

104a, 104b. Alternatively, the angular spacing between the teeth may vary.

In this context, the term "tooth" may refer to any protruding element, such as a blade, fin, arm, or the like.

The wheel 106 of the illustrated example is made of high density closed cell foam. In other embodiments not shown herein, other types of foam or plastic materials may be used. The foam in this embodiment has a minimum of "blow holes" (i.e., holes in the surface of the foam). This prevents very small stone material, such as small particles (melee), from being embedded or otherwise attached to the foam wheel 106 during the dispensing process.

The wheel 106 is resilient. When the wheel 106 is actuated, as the wheel 106 rotates, at least a portion of the

teeth

104a, 104b. At least a portion of the

teeth

104a, 104b. As the runner 106 rotates and the

teeth

104a, 104b. In other words, the

teeth

104a, 104b. "flicking" can increase the speed of the gemstone being dispensed, which is undesirable because the gemstone may travel too far and miss the dispensing bin 105 of the sorting apparatus 101, or may hit the bin 105 and bounce open.

The arrangement of deforming at least a portion of the

teeth

104a, 104b. This allows even very small stones to be reliably dispensed or removed from the surface 103.

In this example, the shape of each

tooth

104a, 104b. This reduces the amount of wear on both the runner 106 and the surface 103. It is also desirable to limit the contact area between the

teeth

104a, 104b. This prevents stalling and heating problems of the motor 116.

Thus, the leading portion 104 of each tooth_LTail (trailing) 104_TExtending further away from the center of the wheel 106. In other words, as best shown in fig. 2B, the teeth 104a, 104B. A front portion 104 of each

tooth

104a, 104b_LFacing the normal direction of travel of the wheel 106, i.e. the direction of rotation when the wheel 106 removes the gemstone from the movable surface 103, which in this example is clockwise. In this example, all of the

teeth

104a, 104b. In this example, each tooth 104a, 104be overall width). It should be understood that the shape of the

teeth

104a, 104b.

Since it is advantageous to minimize contact between the

teeth

104a, 104b. In this case, it is advantageous to arrange the horizontal axis a of the runner 106 such that the

teeth

104a, 104b. Minimal contact may mean as little contact as possible and insufficient to deform the teeth.

In the example shown in fig. 1-4, the runner 106 is connected to a hub (hub)111, the hub 111 including an output shaft 114. For example, the wheel 106 may be glued to the hub 111. The hub 111 is connected to a motor, such as a stepper motor 116. The stepper motor 116 may be configured such that it is required to travel 1000 steps per revolution of the wheel. The stepper motor 116 is configured to drive the wheel 106 about its axis a via the hub 111, i.e. to rotate the wheel 106 about its axis a. Axis a is in the same plane as the horizontal movable surface 103 on which the stone is transported 103.

Figures 5 to 7 show a gemstone sorting apparatus 101 comprising an array of dispensing apparatus 100 as described above configured to dispense gemstones from a horizontally movable surface 103 according to their measured properties. The sorting apparatus 101 includes: one or

more measurement locations

110a, 110b, each measurement location comprising at least one measurement device configured to measure one or more properties of the gemstone; a horizontally movable surface 103 for supporting the gemstone thereon and transporting the gemstone to one or

more measurement locations

110a, 110 b.

In this example, the horizontal movable surface comprises a covered rotatable disc 103 configured to receive a batch of gemstones from the magazine 102. The gemstone is supported on a substantially flat upper surface of the disk 103 rotating at about 30mm/sec and is transported by the disk 103 to an agitator (agitator) 113. Stirrer 113 comprises a pair of opposed parallel vertical walls which form a substantially semicircular channel (not shown here) into which the gemstone is guided by disk 103. The walls are oscillating, which causes the stones present on the surface of the rotating disc 103 to be pushed into their most stable state, i.e. their lowest potential energy position, usually with the top surface (table face) facing downwards.

After orientation, the gemstone is transported on the horizontal surface of the disk 103 through a separation device comprising a series of

cams

107, 108. The

cams

107, 108 are inclined to the direction of travel of the horizontal surface 103 so that the gemstone is pushed towards the outer region of the disc 103, which moves faster than the central region of the disc 103. This increases the spacing between the stones.

After separation, the gemstones pass a position sensor 109, such as a laser curtain, which is configured to send a signal to the controller 117 each time a gemstone passes. The passage of the stones from the position sensor 109 is correlated with the angular position of the disc 103 at that time, and the position of each stone can thus be tracked by knowing the angular position of the disc 103.

As the disc 103 rotates, the separated gemstones then pass one at a time through one or

more measurement locations

110a, 110b, and measurements of gemstone properties (measurements) are transmitted from the measurement devices at the one or

more measurement locations

110a, 110b to the controller 117. Each gemstone is then distributed by the distribution mechanism 100 into a suitable collection bin 105, according to their measured properties, the distribution mechanism 100 removing the gemstone from the surface of the rotatable disc 103. It will be appreciated that the sorting apparatus 101 shown in the example of figures 5 to 7 comprises a plurality of distribution apparatus 100 such that each collection bin 105 has its own associated distribution apparatus 100. Thus, the number of distribution devices 100 may be adjusted according to the number of collection tanks 105 required. In this example, four dispensing devices are provided, so there are four runners 106 and associated hubs 111, motors 116 and sensors 112, each motor 116 being connected to and actuated by a controller 117.

Since the time at which a particular gemstone passes the position sensor 109 and the rotational speed of the disc 103 are known, the controller 117 can accurately predict when the particular gemstone will pass one or more of the

measurement locations

110a, 110 b. Thus, the controller 117 may correlate the measurements of one or more properties of the particular gemstone it receives with the location of the particular gemstone on the rotatable disk 103. The controller 117 may determine whether a particular gemstone is, for example, a natural diamond, a synthetic diamond, or a non-diamond, based on the received measurements. When a particular gemstone reaches a position adjacent to the appropriate collection bin 105, the controller 117 actuates the appropriate motor 116 to its distribution wheel 106 associated with that collection bin 105 to distribute the gemstone from the surface of the rotating disk 103 into the correct collection bin 105.

In use, the motor 116 is actuated by a controller 117 of the sorting apparatus 101 and is used to drive the wheel 106 through a section when a dispensing operation is required. In other words, the runner 106 is driven by the motor 116 such that it rotates through the distance between the centers of two

adjacent teeth

104a, 104b.

The starting position of the jog dial 106 is important because the jog dial 106 must be moved away from the movable surface 103 when not dispensing. To achieve this, the position of the wheel 106 must be set (reset) to a predetermined position by the motor 116 at the start of each sorting operation. There are many ways in which this can be achieved, but in this example, the sensor 112 is mounted above the wheel 106. The sensor 112 may include, for example, a laser curtain, a micro switch, or a hall effect sensor. The

uppermost teeth

104a, 104b. During an initial homing operation (i.e., at the beginning of each sort operation), the direction of rotation of the wheel 106 may be a first, normal direction of rotation (e.g., clockwise).

Alternatively, the direction of rotation of the wheel 106 during the initial homing operation may be in a second, opposite (in other words, reverse, i.e., counterclockwise), opposite direction. Reverse homing ensures that any gemstone left on the tray 103 after the previous sorting operation is not mistakenly dispensed into the collection bin 105. By homing in the reverse direction, any stones on disk 103 are swept back toward the center of disk 103 and recycled by the feed mechanisms (feed mechanisms) discussed above.

In the case of a five-tooth wheel 106, the motor 116 may drive 200 steps from the home position (i.e., 1000 steps per full circle of the wheel 106) for each dispense cycle. In this example, the wheel 106 is parked whenever a dispense cycle occurs, and the wheel 106 is driven by the motor 116 until the sensor 112 is triggered by the

next tooth

104a, 104b. In other words, after controller 117 of sorting apparatus 101 activates motor 116, sensor 112 is configured to send a signal to stop motor 116 when one of

teeth

104a, 104b. The wheel 106 is then decelerated and stopped very quickly by the motor 116. It is to be understood that any of the

teeth

104a, 104b.

The thickness of the wheel 106 (in this example about 8mm) and the time it takes to complete a dispensing cycle are both important to achieve dispensing of gemstones with minimal separation between the gemstones. In this example, the jog dial 106 is driven such that a single dispensing motion can be completed within 100 ms. A single dispensing motion is understood to mean dispensing of a single gemstone and rotation of the wheel 106 by the distance between the centers of two

adjacent teeth

104a, 104b. During this time, the movable disk 103 over which the gemstone is traveling will typically move by about 3 mm. Thus, the dispensing apparatus 100 may dispense gemstones without stopping the movable plate 103. This greatly increases the throughput of the sorting apparatus 101.

As shown in fig. 3, in its home position, the wheel 106 is supported above the horizontal surface of the movable disk 103 in such a way as to define a clearance (clear gap) in the region of the path of the gemstone between the

lowermost teeth

104a, 104b. This gap allows gemstones within a certain size range to be fed under the wheel 106 and past the wheel 106 without the need to dispense the gemstones at this location. If a gemstone is to be dispensed, as shown in the example of fig. 4, the wheel 106 is driven clockwise to complete the dispensing motion, wherein one

tooth

104a, 104b of the wheel 106 contacts the gemstone and pushes it off the disc 103 and into a dispensing bin 105, which bin 105 is positioned at the outer edge of the disc 103 and below the outer edge of the disc 103, as shown in fig. 4. As previously described, a portion of the

teeth

104a, 104b.

Once the sensor 112 detects any of the

teeth

104a, 104b. It should be understood that the sensor 112 may be arranged such that not the

uppermost teeth

104a, 104b. For example, the sensor 112 may be arranged to detect any of the

teeth

104a, 104b at a rotational position of any of the wheels 106. Further, the sensor 112 may be configured to detect the position of a particular one of the

teeth

104a, 104b.

Alternatively, the stepper motor 116 may be driven a predetermined number of steps very quickly so that the

teeth

104a, 104b. The last few steps may be performed more slowly to allow the sensor 112 to more accurately detect the

teeth

104a, 104b. Once the sensor 112 detects the

teeth

104a, 104b.

The method of dispensing a gemstone from a horizontally movable surface is described with reference to fig. 8. The method comprises the following steps: rotating a wheel about a horizontal axis above the surface with a motor, the wheel including one or more teeth disposed about its periphery and the horizontal axis being positioned such that when the wheel is in a home position, a gap exists between the wheel and the surface; identifying when one of the teeth is in a predetermined position using a sensor to indicate that the wheel is in a home position; stopping the rotation of the rotating wheel at the homing position; as the gemstone passes the wheel, the wheel is further rotated so that one of the teeth contacts the gemstone and pushes the gemstone away from the surface.

The method for sorting the precious stones by using the sorting device 101 comprises the following steps: the method comprises supporting the gemstone on a horizontal movable surface 103, transporting the gemstone with the surface 103 to one or

more measurement locations

110a, 110b, measuring one or more properties of the gemstone at the one or

more measurement locations

110a, 110b, and dispensing the gemstone from the horizontal movable surface 103 using one or more dispensing devices 100 in accordance with the measured properties of the gemstone.

In the event that it is desired that at least a portion of the

teeth

104a, 104b.

It will be appreciated by those skilled in the art that various modifications could be made to the above-described embodiments without departing from the scope of the invention. For example, the thickness and shape of the wheel 106 may be adapted for different applications, or for dispensing significantly larger or smaller gemstones.

In another embodiment, the dispensing apparatus 100 may be arranged such that the wheel 106 may be selectively operated to rotate in the reverse direction, i.e. in the opposite direction to that normally used to dispense gemstones from the surface of the disc 103 and into the collection bin 105. Reversing the direction of rotation of the wheel 106 may cause the gemstone to be directed towards the inside of the rotatable disc 103 rather than being pushed away from the edge of the disc 103. This may be desirable in the event that the gemstone arriving at the dispensing location is not sufficiently separated, or in the event that the measurement of the gemstone's properties fails and requires re-measurement.

Claims

1. A dispensing apparatus for dispensing a gemstone from a horizontal movable surface, the dispensing apparatus comprising:

a wheel arranged to rotate about a horizontal axis located above the surface and comprising one or more teeth arranged around the periphery of the wheel;

a motor for rotating the wheel; and

a sensor configured to identify when one of the teeth is in a predetermined position to indicate that the wheel is in a home position;

wherein the runner is arranged to define a gap between the surface and the runner when the runner is in a home position;

and wherein the wheel is arranged such that one of the teeth contacts the gemstone as the wheel rotates away from the home position to push the gemstone away from the surface.

2. The dispensing apparatus of claim 1, wherein the wheel is arranged such that one of the teeth is in contact with the horizontally movable surface when the wheel is rotated away from the home position and pushes the gemstone away from the surface.

3. The dispensing apparatus of claim 1, wherein the horizontal axis is substantially parallel to a direction of travel of the surface.

4. A dispensing apparatus as claimed in any of claims 1 to 3, in which the wheel comprises a plurality of teeth, the teeth being equiangularly disposed about the periphery of the wheel.

5. A dispensing device as claimed in claim 4, wherein the home position is defined as the position when the uppermost tooth is in the predetermined position.

6. A dispensing device as claimed in any of claims 1 to 3, in which the wheel comprises five equiangularly spaced teeth.

7. A dispensing apparatus as claimed in any of claims 1 to 3, in which each tooth comprises a front portion and a rear portion, the front portion extending further from the centre of the wheel than the rear portion.

8. A dispensing apparatus as claimed in any of claims 1 to 3, wherein the wheel comprises a closed cell foam material.

9. A dispensing device as claimed in any of claims 1 to 3, wherein the sensor comprises a light curtain.

10. A dispensing apparatus as claimed in any of claims 1 to 3, configured to move the wheel to the home position after actuation of the motor.

11. A dispensing apparatus according to any of claims 1 to 3, wherein the wheel is configured to be driven in a first direction when dispensing a gemstone from the horizontal movable surface, and wherein the wheel is configured to be driven in a second, opposite direction when directing a gemstone to another region of the horizontal movable surface.

12. An apparatus for sorting gemstones, comprising:

one or more measurement locations, each measurement location comprising at least one measurement device configured to measure one or more properties of the gemstone;

a horizontal movable surface for supporting the gemstone thereon and transporting the gemstone to the one or more measurement locations;

one or more dispensing devices according to any of claims 1 to 11, configured to dispense the gemstone from the horizontally movable surface according to a measured property of the gemstone.

13. The apparatus for sorting gemstones according to claim 12, comprising a controller configured to actuate a motor of each of said one or more dispensing apparatuses.

14. Apparatus for sorting gemstones according to claim 12 or 13, comprising a collection bin associated with each of said one or more distribution apparatus.

15. Apparatus for sorting gemstones according to claim 12 or 13, comprising a plurality of dispensing devices arranged in an array such that the gemstones on the horizontally movable surface pass successively through the wheels of said plurality of dispensing devices.

16. A method of dispensing a gemstone from a moving horizontal surface, comprising:

rotating a wheel about a horizontal axis above the surface with a motor, the wheel comprising one or more teeth disposed about its periphery, and the horizontal axis being positioned such that when the wheel is in a home position, a gap exists between the wheel and the surface;

identifying with a sensor when one of said teeth is in a predetermined position to indicate that the wheel is in said home position;

stopping rotation of the wheel at the home position;

as the gemstone passes the wheel, the wheel is further rotated so that one of the teeth contacts the gemstone and pushes the gemstone away from the surface.

17. The method of dispensing gemstones according to claim 16, wherein said horizontal axis is positioned such that when said gemstones are further rotated by said wheel, one of said teeth contacts said moving horizontal surface as the gemstones are pushed out of said surface.

18. The method of dispensing gemstones according to claim 16, wherein said horizontal axis is substantially parallel to the direction of travel of said surface.

19. The method of dispensing gemstones according to any one of claims 16 to 18, wherein said wheel comprises a plurality of teeth equiangularly disposed around the periphery of said wheel.

20. The method of dispensing gemstones according to any one of claims 16 to 18, wherein each tooth has a front portion and a rear portion, said front portion extending further from the center of said wheel than said rear portion.

21. The method of dispensing gemstones according to any one of claims 16 to 18, comprising moving said wheel to said home position after actuating said motor.

22. A method of dispensing gemstones according to any one of claims 16 to 18, comprising: the wheel is driven in a first direction when a gemstone is dispensed from the horizontally movable surface, and in a second, opposite direction when the gemstone is directed to another region of the horizontally movable surface.

23. A method of sorting gemstones, comprising:

supporting the gemstone on a horizontal movable surface;

transporting the gemstone with the surface to one or more measurement locations;

measuring one or more properties of the gemstone at the one or more measurement locations;

dispensing a gemstone from a horizontally moveable surface according to a measured property of the gemstone with one or more dispensing apparatuses according to any of claims 1 to 11.

24. The method of sorting gemstones according to claim 23, comprising actuating a motor of each of said one or more dispensing devices with a controller.

25. A method of sorting gemstones according to claim 23 or 24 comprising associating a collection bin with each of said one or more distribution devices.

26. The method of sorting gemstones according to claim 23 or 24, comprising arranging a plurality of dispensing devices in an array such that the gemstones on the horizontally movable surface pass successively through the wheels of said plurality of dispensing devices.