WO2021058108A1

WO2021058108A1 - Device for picking objects in a predefined orientation from a recipient and method of using it

Info

Publication number: WO2021058108A1
Application number: PCT/EP2019/076167
Authority: WO
Inventors: Marc Van Biesen
Original assignee: Newson Nv; Bls-Gemscriptor Lasers Bvba
Priority date: 2019-09-27
Filing date: 2019-09-27
Publication date: 2021-04-01
Also published as: BE1027571B1; BE1027571A1

Abstract

The current invention relates to a device for picking up objects, said objects comprising a pyramidally shaped end (9) and an substantially flat surface (11, 5) on the opposite end, in a predefined orientation.The inventions also relates to a method for picking up objects in a predefined orientation, said objects comprising a pyramidally shaped end (9) and an essentially flat surface (11, 5) on the opposite end.

Description

DEVICE FOR PICKING OBJECTS IN A PREDEFINED ORIENTATION FROM A RECIPIENT AND METHOD OF USING IT

FI ELD OF THE I NVENTI ON

The present invention relates to a device for picking up objects, said objects comprising a pyramidally shaped end and an substantially flat surface on the opposite end, in a predefined orientation.

In a second aspect, the present invention also relates to a method for picking up objects in a predefined orientation.

The present invention relates to applications where picking of objects from a bulk recipient with objects in multiple orientations is required, as e.g. picking small size diamonds from a recipient.

BACKGROUND

Devices for picking up objects, comprising a pyramidally shaped end and an substantially flat surface on the opposite end, in a predefined orientation from a bulk recipient are necessary in many applications, in particular in applications concerned with laser manipulation processes such as laser scanning, laser engraving, laser marking, laser ablation or laser etching where a correct alignment of the object with respect to the laser is essential.

Such a device is known from US20150015877. The device comprises a vacuum nozzle, comprising a tube with an inner channel. The inner channel is partially blocked from the inlet by an obstruction. The obstruction is supported by discrete arms extending laterally from the tube.

US20150015877 further describes an alternative device, comprising a vacuum nozzle. The vacuum nozzle has a generally flat bottom with a plurality of apertures.

The first device according to US20150015877 has the following problem . The device can pick up objects in different orientations, different from the predefined orientation. The alternative device according to US20150015877 overcomes the problem of picking up objects in different orientations, but picks up objects with the substantially flat surface towards the device, what is opposite to the predefined orientation.

Further US20150015877 describes no method to adjust or to verify the orientation of an object.

The aim of the invention is to provide a device and a method which elim inates those disadvantages.

SUMMARY OF TH E I NVENTI ON

The present invention and embodiments thereof serve to provide a solution to one or more of above-mentioned disadvantages. To this end, the present invention relates to a device for picking objects in a predefined orientation according to claim 1 .

By the term “object” as used herein, is meant that the object comprises a pyramidally shaped end and a substantially flat surface on the opposite end. Objects can include, but are not limited to, a pyramid, a cone, a half-sphere or a diamond. The predefined orientation is with the pyramidally shaped end of the object towards the inlet of the vacuum nozzle and the substantially flat surface of the object perpendicular to the axis of the vacuum nozzle. The opposite orientation is with the substantially flat surface of the object towards the inlet of the vacuum nozzle, perpendicular to the axis of the vacuum nozzle.

The advantage of such a device lies in the reliance on at least one radial groove at the inlet side to pick the object in the predefined orientation. I n the prior art US20150015877, the vacuum nozzle has facilities, being walls surrounding the inlet, for picking the object according to a certain orientation, in this case the opposite orientation. Flowever, the walls cannot prevent that the object can be picked in the predefined or the opposite direction. I n another embodiment of the vacuum nozzle in same prior art US20150015877 the vacuum nozzle has improved facilities, being multiple inlets, for picking an object according to a certain direction, still being the opposite direction. The present invention overcomes this by relying on the fact that only in the predefined orientation (i.e. with the pyram idally shaped end partly in the nozzle) the object closes the inlet of the vacuum nozzle sufficiently, enabling to lower the pressure inside the inner channel of the vacuum nozzle compared to the outside of the vacuum nozzle , what is required for picking an object with the vacuum nozzle.

Additionally, it should be noted that in some industries, for instance gem (diamond) processing, a part of the process may include providing markings on the “table” (the flat top surface of a cut gem). I n industrial settings, which typically deal with low carat stones (0.5 - 4 carats, typically 1 - 2 carats), high amounts of the stones are being processed in bulk, and require a fast and guaranteed tool for the proper orientation. As such, the prior art device needs a further step/tool to allow the table to be available for marking. Given the small size of the stones that are marked in this way, this is a cumbersome operation and would increase costs due to the need for additional machinery, aside from adding a step to the process in which an error can occur. Reduction of number of steps is crucial in any industrial process, for sake of efficiency in costs and performance.

Preferred embodiments of the device are shown in any of the claims.

In a second aspect, the present invention relates to a method according to the claims. More particular, the method as described herein provides that objects can be picked up from a recipient in a predefined orientation. In prior art systems, this is commonly done by means of a visual inspection system , inspecting the orientation of the object after picking. However, when picking the object was not according the predefined orientation, this results in releasing the object and trying another attempt to pick the object. The present invention overcomes this using the device from claim 1 . The object is picked in the predefined orientation, making the visual inspection system superfluous and avoiding reattempts to pick the object in the predefined orientation.

Preferred embodiments of the method are shown in any of the claims.

Further embodiments and their advantages are described in the detailed description and the claims.

DESCRI PTI ON OF FI GURES

The following description of the figures of specific embodiments of the invention is merely exemplary in nature and is not intended to limit the present teachings, their application or uses. Throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features.

Figure 1 - prior art - shows an axial cross-sectional view of a prior art vacuum nozzle.

This figure is discussed in further detail in Example 1 .

Figure 2 - prior art - shows a view of an alternative prior art vacuum nozzle.

Figure 3 shows a bottom view of a nozzle of an embodiment of the present invention.

Figure 4 shows schematically the attraction of an object in the inlet according to the predefined orientation.

Figure 5 shows schematically the attraction of an object in the inlet according to the opposite orientation.

Figure 6 shows schematically how the orientation of an object can be verified.

DETAI LED DESCRI PTI ON OF THE I NVENTI ON

Unless otherwise defined, all terms used in disclosing the invention, including technical and scientific terms, have the meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. By means of further guidance, term definitions are included to better appreciate the teaching of the present invention.

I n this document, an “object” comprises a pyram idally shaped end and a substantially flat surface on the opposite end. Objects can include, but are not limited to, a pyram id, a cone, a half-sphere or a diamond. I n a particular embodiment, the objects are gemstones, particularly cut gemstones, and most particularly cut diamonds.

I n this document the term “predefined orientation” refers to an orientation with the pyramidally shaped end of the object towards the inlet of the vacuum nozzle and the substantially flat surface of the object perpendicular to the axis of the vacuum nozzle. Reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment, but may. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner, as would be apparent to a person skilled in the art from this disclosure, in one or more embodiments. Furthermore, while some embodiments described herein include some but not other features included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the invention, and form different embodiments, as would be understood by those in the art. For example, in the following claims, any of the claimed embodiments can be used in any combination.

The present invention relates to a device for picking objects in a predefined orientation according to the claims.

In a preferred embodiment the device comprises a vacuum nozzle. The vacuum nozzle comprises a tube with an inner channel and enveloped by a mantle. The tube comprises an inlet at a first end of the tube, with said inlet being in connection with the inner channel. The device is further provided with a pressure control means suitable for controlling the pressure within the inner channel of the vacuum nozzle. The vacuum nozzle comprises at least one, preferably two, three, four or more, radial groove at the first end of the tube, said radial groove extending fully through the mantle of the tube. The device further comprises a transport means adapted for moving the vacuum nozzle in at least a first and second direction, said first and second direction not being parallel and preferably mutually perpendicular. The device also comprises a pressure measuring means for measuring a pressure in the inner channel of the vacuum nozzle.

Preferably, the pressure measuring means is adapted for measuring the pressure in the inner channel at the first end of the tube, as the pressure there reflects the achieved effect better (than for instance close to where the pressure control means connects to the vacuum nozzle). In a preferred embodiment, the minimal length of the vacuum nozzle is 1 mm . Preferably, the minimal length of the vacuum nozzle is 3 mm . Even more preferably, the minimal length of the vacuum nozzle is 5 mm .

In a preferred embodiment, the maximal length of the vacuum nozzle is 50 mm . Preferably, the maximal length of the vacuum nozzle is 40 mm. Even more preferably, the maximal length of the vacuum nozzle is 30 mm.

I n a preferred embodiment, the minimal outer diameter of the vacuum nozzle, at least at the first end of the vacuum nozzle but preferably over the entire length of the vacuum nozzle, is 1 mm . Preferably, the minimal outer diameter, at least at the first end of the vacuum nozzle but preferably over the entire length of the vacuum nozzle, is 3 mm . Even more preferably, the minimal outer diameter, at least at the first end of the vacuum nozzle but preferably over the entire length of the vacuum nozzle, is 5 mm .

In a preferred embodiment, the maximal outer diameter of the vacuum nozzle, at least at the first end of the vacuum nozzle but preferably over the entire length of the vacuum nozzle, is 20 mm . Preferably, the maximal outer diameter, at least at the first end of the vacuum nozzle but preferably over the entire length of the vacuum nozzle, is 15 mm. Even more preferably, the maximal outer diameter, at least at the first end of the vacuum nozzle but preferably over the entire length of the vacuum nozzle, is 15 mm.

In an embodiment, the outer diameter of the vacuum nozzle increases from the first end of the vacuum nozzle towards the second end. This is particularly advantageous in case the vacuum nozzle has an outer diameter below a certain value (such as less than 3 mm) to increase the mechanical strength of the vacuum nozzle.

In some cases, the outer diameter may vary, having two or more sections each with a substantially constant outer diameter, and either discrete or gradient transitions therein between.

In an embodiment, the circumference of the vacuum nozzle is non-cylindrical, e.g. oval-shaped or another suitable shape. This is particularly advantageous in case the vacuum nozzle has an outer diameter below a certain value (such as less than 3 mm) to increase the mechanical strength of the vacuum nozzle. The vacuum nozzle may comprise metal, polymer, composite materials, textiles, plastic, and any combination of one or more of the above. A possible embodiment provides for a vacuum nozzle that comprises several layers, wherein the layers differ in material make-up.

I n a preferred embodiment, the mantle of the vacuum nozzle has a thickness, at least at the first end of the vacuum nozzle but preferably over the entire length of the vacuum nozzle, of at least 0.2 m m . Preferably, the thickness, at least at the first end of the vacuum nozzle but preferably over the entire length of the vacuum nozzle, is at least 0.35 mm . Even more preferably, the thickness, at least at the first end of the vacuum nozzle but preferably over the entire length of the vacuum nozzle, is at least 0.5 m m .

I n a preferred embodiment, the mantle of the vacuum nozzle has a thickness, at least at the first end of the vacuum nozzle but preferably over the entire length of the vacuum nozzle, of at most 5 m m . Preferably, the thickness, at least at the first end of the vacuum nozzle but preferably over the entire length of the vacuum nozzle, is at most 3 m m . Even more preferably, the thickness, at least at the first end of the vacuum nozzle but preferably over the entire length of the vacuum nozzle, is at most 2 m m .

I n an embodiment the dimension of the inner channel increases above the inlet. This reduces air leaks when the nozzle is closed by a picked up object in predefined orientation.

I n some cases, the inner diameter may vary, having two or more sections each with a substantially constant inner diameter, and either discrete or gradient transitions therein between. As such, embodiments are envisaged wherein a section at the first end of the nozzle has a lower inner diameter than sections further away from said first end. The length of said section at the first end can range anywhere between a 1 .0 m m up to several cm or even more. This is particularly advantageous in case of vacuum nozzles with an outer diameter at the first end below a certain value (such as less than 1 mm) to reduce the friction losses for the airflow in the inner channel.

I n an embodiment the circumference of the inner channel above the inlet is non- cylindrical, e.g. oval-shaped or another suitable shape. I n an embodiment the object can be picked up by the device by applying a pressure in the inner channel lower than the atmospheric pressure outside the vacuum nozzle using the pressure control means. Due to the pressure difference between the outside of the vacuum nozzle and the inner channel, an object can be attracted to the inlet when close enough to said inlet. When the object is attracted to the inlet in the correct, predefined orientation (i.e. with the pyramidally shaped end towards the inlet) , the pyramidally shaped end of the object will enter the inlet and substantially block the inner channel of the vacuum nozzle substantially. Because of the substantial blockage of the inner channel, the pressure measuring means will measure a pressure in the inner channel lower than the atmospheric pressure, and in particular lower than a predefined pressure threshold that itself is lower than the atmospheric pressure, indicating that an object is picked in the predefined orientation by the vacuum nozzle. The transport means can, upon detection of the measured pressure being below the predefined pressure threshold, subsequently move the vacuum nozzle with the object to another location.

When the object is attracted to the inlet in the opposite orientation, the substantially flat surface of the objected will touch, but not be able to enter the inlet. The groove(s) allows air to enter the inner channel and consequently the inner channel is not blocked sufficiently to reach the predefined pressure threshold. The pressure measuring means will measure approximately the same pressure in the inner channel as the atmospheric pressure and no picking action will be executed.

I n a preferred embodiment of the device, the device is provided with a recipient suitable for holding a plurality of objects in an open interior volume of the recipient. The interior volume of said recipient is accessible to the vacuum nozzle. I n such an embodiment the objects are in a confined space, increasing the chance when moving the vacuum nozzle with the transport means that an object may be found and may be picked.

The recipient may be beam-shaped, cylindrical-shaped, a cone, a bowl, ovoid (or a truncated variation of any of the above) but is not lim ited to the above. The material of the recipient may comprise metal, plastic, glass or even cardboard. Preferably, the open top surface of the recipient is equal or bigger size than the bottom surface of the recipient. I n case of a beam-shaped or cylindrical shaped recipient, the longitudinal axis of the recipient is preferably tilted with respect to a vertical axis. This has the effect that the objects are concentrated in the lowest part of the recipient.

The recipient is tilted at least 0° , more preferably at least 15° , even more preferably 30° .

The recipient is tilted at most 75° , more preferably at most 60° , even more preferably 45° .

I n the most preferred embodiment of the device, the recipient and vacuum nozzle are adapted for relative movements with respect to each other. I n such an embodiment the recipient can move relative to the position of the vacuum nozzle to present another object to the vacuum nozzle. The relative movement of the recipient can also shake the objects in the recipient, which can change the orientation of an object to the predefined orientation with respect to the nozzle, thus allowing pick up by the vacuum nozzle. The relative movement of the vacuum nozzle to the position of the recipient has sim ilar effects. Another object can be presented to the vacuum nozzle or the vacuum nozzle can push an object and turn it to its predefined position.

I n an embodiment of the device, the vacuum nozzle is substantially im mobile (while picking up an object, though it may be moved after successful pick-up) . The recipient is movable along one or more of three perpendicular axes. Two axes are in a horizontal plane and the third axis is vertical. The recipient is be movable along the vertical axis to bring the inlet of the vacuum nozzle below the level of the objects and down to pull the vacuum nozzle out of the recipient. Alternatively, the recipient may be movable vertically with the nozzle inlet remaining below the level of the objects. Note that the movement may also vary between the two alternatives. The recipient may be movable along one or both of the two horizontal axes simultaneously or the movement may alternate along the two horizontal axes in order to perform a search pattern with the vacuum nozzle in the recipient. An embodiment can be conceived wherein the recipient is movable in a circular, elliptical, eight-shaped pattern in the horizontal plane.

I n a preferred embodiment, one or more of the above movements may be combined, either alternatingly or jointly, and in particular joint combinations of vertical and horizontal movements. I n an embodiment of the device, the recipient is im mobile (during pick-up) . The vacuum nozzle is movable along one or more of three perpendicular axes. Two axes are in a horizontal plane and the third axis is vertical. The vacuum nozzle may be movable down along the vertical axis to bring the inlet of the vacuum nozzle below the level of the objects and may be movable up to pull the vacuum nozzle out of the recipient. Alternatively, the nozzle may be movable vertically with the nozzle inlet remaining below the level of the objects. Note that the movement may also vary between the two alternatives. The vacuum nozzle may be movable along one or both horizontal axes simultaneously or the movement may alternate along the two horizontal axes in order to perform a search pattern with the vacuum nozzle in the recipient. An embodiment can be conceived wherein the nozzle is movable in a circular, elliptical, eight-shaped pattern in the horizontal plane.

I n a preferred embodiment, one or more of the above movements may be combined, either alter natingly or jointly, and in particular joint combinations of vertical and horizontal movements.

I n an embodiment of the device, the vacuum nozzle is movable along at least one of three perpendicular axes (vertical axis and two horizontal axes) . The recipient is also movable along at least one of said three perpendicular axes. I n a particular embodiment, the vacuum nozzle is movable along the vertical axis. The recipient is movable along the two horizontal axes or the movement may alternate along the two horizontal axes in order to perform a search pattern with the vacuum nozzle in the recipient.

I n a further embodiment of the device, the recipient may be adapted to oscillate in order to shake the objects. Note that this oscillation can be superimposed on other relative movements of the recipient and/or vacuum nozzle in order to execute a search pattern. The movement speed of the oscillation is at least twice the speed of the relative movements of the recipient and/or vacuum nozzle in order to execute a search pattern. The amplitude of the oscillation movement is in the range of 0,5 cm up to 5 cm . The oscillation movements can be executed along a longitudinal axis, a horizontal axis, simultaneously along two perpendicular horizontal axes or alternatingly along two perpendicular horizontal axes. The horizontal axes of the oscillation movements may, but do not have to correspond with the two perpendicular horizontal axes of the relative movements of the recipient and/or vacuum nozzle in order to execute a search pattern. I n a preferred embodiment of the device, the device comprises a control system for controlling the relative movements of the recipient and the vacuum nozzle with respect to each other and for controlling the transport means. I n such an embodiment the control system is preferably adapted to automatically control the relative movements of the recipient and the vacuum nozzle with respect to each other in order to present another object to the vacuum nozzle and to change the orientation of the objects in the recipient. The control system is preferably also adapted for controlling the transport means and to automatically move the vacuum nozzle from the recipient to another location when the vacuum nozzle successfully picked up an object.

I n an embodiment of the device, the size of the surface of the inlet of the vacuum nozzle is smaller than the substantially flat surface of the object. I n such an embodiment, when the object is attracted to the inlet of the vacuum nozzle in the opposite orientation, the surface of the inlet is too small to allow the object to enter the inlet in the opposite orientation and the vacuum nozzle cannot pick the object.

I n an embodiment of the device, the vacuum nozzle is adapted for picking diamonds with a table and a pavilion and/or culet, said pavilion and/or culet comprising a plurality of facets. The outer diameter of the tube has to be m inimally equal to the dimension of the table (substantially flat surface of the object) of the diamond, which corresponds with about 50% of the size of a diamond with ideal proportions. Preferably, the size of the inlet of the vacuum nozzle is in the range of 30% to 40% of the size of a diamond with ideal proportions so that the pavilion of the diamond and/or culet of the diamond can enter the inlet deep enough to sufficiently block the inlet. The depth of the grooves is in the range of 10% to 15% of the size of a diamond with ideal proportions. All the grooves have preferably the same width. The perimeter of the inlet over which the grooves extend combined is equal to at least 5% , preferably at least 10% , and up to 60% of the circumference of the tube.

Minimal tube diameter, minimal and maximal inlet size and minimal and maximal depth of grooves in function of the weight of a diamond with ideal proportions.

I n a further embodiment of the device, the radial grooves are positioned in a pattern according to the facets of the pavilion and/or culet.

I n an embodiment of the device, the vacuum nozzle is intended for picking objects comprising a pyramidally shaped end and a substantially flat surface on the opposite end, whereby the substantially flat surface forms a regular polygon and whereby the vacuum nozzle comprises at least three grooves, the grooves being positioned to correspond to the vertices of the regular polygon of the substantially flat surface. The outer diameter of the tube has to be minimal equal to the dimension of the substantially flat surface of the object. The size of the inlet of the vacuum nozzle is in the range of 60% to 80% of the size of the object so that the pyramidally shaped end of the object can enter the inlet deep enough to sufficiently block the inlet. Preferably, the depth of the grooves is in the range of 20% to 30% of the diameter of the object. All the grooves have preferably the same width. The perimeter of the inlet over which the grooves extend combined is equal to 5% up to 60% of the circumference of the tube.

I n an embodiment of the device, the vacuum nozzle comprises an inlet with a deformable cladding at the inside of the inlet. The deformable cladding preferably comprises rubber, foam , silicone. The size of the inlet of the vacuum nozzle preferably is in the range of 65% to 90% of the size of the object so that the pyramidally shaped end of the object can enter the inlet and will compress the deformable cladding at the inside of the inlet. The compression of the deformable cladding can form a seal around the pyram idally shaped end of the object upon insertion, which will substantially block the grooves in the first end of the vacuum nozzle. This is beneficial when objects with different substantially flat surfaces have to be picked from a same recipient, for instance objects with a substantially flat surface that forms a triangle, hexagon, octagon, circle... I n such an embodiment the depth of the grooves is in the range of 20% to 30% of the diameter of the object. All the grooves preferably have the same width. The perimeter of the inlet over which the grooves extend combined is equal to 5% , preferably 10, up to 60% of the circumference of the tube.

I n an embodiment of the device, the mantle is chamfered internally at the inlet. This can be understood as the mantle being internally chamfered or beveled at the inlet, wherein the radius of the inner channel increases towards the first end.

The chamfer is preferably created at an angle between 20° and 70° between the inlet and the first end of the vacuum nozzle. The chamfer improves the blockage of the grooves by an object when it enters the inlet according to the predefined orientation. Preferably, said angle ranges between 30° and 60° , more preferably between 35° and 55° , although it can be foreseen to correspond to the form of the objects to be picked up (in the example of diamonds, to the pavilion angle) . The angle above can be understood to be the angle at which the chamfer/bevel diverges away from a virtual (tangential) continuation of the nozzle.

I n a second aspect, the present invention relates to a method according to the claims.

I n an embodiment the method comprises multiple steps. A pressure is applied in the inner channel using the pressure control means that is lower than the atmospheric pressure outside of the vacuum nozzle. The inlet of the vacuum nozzle is inserted in the recipient to a level below that of the objects in order to facilitate the attraction of the objects to the inlet of the vacuum nozzle. The vacuum nozzle comprises a tube with an inner channel, which inner channel is enveloped by a mantle. The tube comprises an inlet at a first end of the tube, with said inlet being in connection with the inner channel. The pressure inside the inner channel is measured, preferably at a position close to the first end of the tube. Due to the pressure difference between the outside of the vacuum nozzle and the inner channel, an object can be attracted to the inlet. When the object is attracted to the inlet, and is provided to the inlet in the predefined orientation (i.e. with the pyramidally shaped end towards the inlet) , the pyramidally shaped end of the object will partially enter the inlet and substantially block the inner channel of the vacuum nozzle. Because of the substantial blockage of the inner channel, the pressure in the inner channel that is measured will be substantially lower than the atmospheric pressure, and in particular lower than a predefined pressure threshold (which itself is lower than the atmospheric pressure) , indicating that an object is picked in the defined orientation by the vacuum nozzle. When the object is attracted to the inlet in the opposite orientation, the substantially flat surface of the objected will touch, but not be able to partially enter the inlet. The groove(s) allows air to enter the inner channel and consequently the inner channel is insufficiently blocked to achieve a pressure inside of the inner channel that is lower than the predefined pressure threshold, and in fact, approximately the same pressure as the atmospheric pressure will be measured in the inner channel in such a case. I n such an embodiment, only when the measured pressure is detected to drop below a predeterm ined pressure threshold, the vacuum nozzle is removed from the recipient, withdrawing an object in the predefined orientation.

I n an embodiment of the method, the vacuum nozzle is immobile. The recipient can move relatively to the vacuum nozzle along three perpendicular axes. Two axes are in a horizontal plane and the third axis is vertical. The recipient moves up along the vertical axis to bring the vacuum nozzle below the level of the objects in order to facilitate the attraction of the objects to the inlet of the vacuum nozzle. The recipient moves simultaneously along the two horizontal axes or alternatingly along one of the two horizontal axes in order to perform a search pattern with the vacuum nozzle in the recipient. The movements of the recipient relatively to the vacuum nozzle can result in the presentation of another object to the vacuum nozzle. The vacuum nozzle can push against an object in the recipient, which can change the orientation of the object to the predefined orientation.

I n an embodiment of the method, the recipient is im mobile. The vacuum nozzle can move relatively to the recipient along three perpendicular axes. Two axes are in a horizontal plane and the third axis is vertical. The vacuum nozzle moves down along the vertical axis to bring the vacuum nozzle below the level of the objects in order to facilitate the attraction of the objects to the inlet of the vacuum nozzle. The vacuum nozzle moves simultaneously along the two horizontal axes or alternatingly along one of the two horizontal axes in order to perform a search pattern with the vacuum nozzle in the recipient. The movements of the vacuum nozzle relatively to the recipient can result in the presentation of another object to the vacuum nozzle. The vacuum nozzle can push against an object in the recipient, which can change the orientation of the object to the predefined orientation.

I n a preferred embodiment of the method, the vacuum nozzle moves relatively to the recipient along a vertical axis and the recipient can move relatively to the vacuum nozzle along two perpendicular axes in a horizontal plane. The vacuum nozzle moves down along the vertical axis to bring the vacuum nozzle below the level of the objects in order to facilitate the attraction of the objects to the inlet of the vacuum nozzle. The recipient moves simultaneously along the two horizontal axes or alter nat ingly along one of the two horizontal axes in order to perform a search pattern with the vacuum nozzle in the recipient. The movements of the recipient relatively to the vacuum nozzle can result in the presentation of another object to the vacuum nozzle. The vacuum nozzle can push against an object in the recipient, which can change the orientation of the object to the predefined orientation.

We note that for each of the above variations, an object that is attracted to the inlet of the vacuum nozzle in the opposite orientation will very likely be pushed off the inlet by the other objects in the recipient due to the relative movements between the recipient and the vacuum nozzle. The objects have a weaker attraction to the inlet of the vacuum nozzle in the opposite orientation than in the predefined orientation and are also more exposed to collisions with other objects because the pyramidally shaped end of the object is not inside the inlet of the vacuum nozzle, resulting in a larger volume that is available for collisions.

I n a further embodiment of the method, an oscillation movement of the recipient relatively to the vacuum nozzle in order to shake the objects is superimposed on the relative movements of the recipient and/or vacuum nozzle in order to execute a search pattern. The speed of the oscillation movement is at least twice the speed of the relative movements of the recipient and/or vacuum nozzle in order to execute a search pattern. The amplitude of the oscillation movement is in the range of 0,5 cm up to 5 cm . The oscillation movements can be executed along a longitudinal axis, a horizontal axis, simultaneously along two perpendicular horizontal axes or alternatingly along two perpendicular horizontal axes. The horizontal axes of the oscillation movements may, but do not have to correspond with the two perpendicular horizontal axes of the relative movements of the recipient and/or vacuum nozzle in order to execute a search pattern.

I n an embodiment of the method the relative movements of the recipient and the vacuum nozzle continue at least until the detection of the measured pressure in the inner channel being lower than the predetermined pressure threshold, indicating that an object is attracted to the inlet of the vacuum nozzle in the predefined orientation and can be picked by the vacuum nozzle. In an embodiment, the predetermined pressure threshold is at least 100 mbar lower than the atmospheric pressure. Preferably the predetermined pressure threshold is at least 200 mbar, more preferably at least 300, 400 or even 500 mbar, lower than the atmospheric pressure.

I n a further embodiment of the method, after removing the vacuum nozzle from the recipient (when holding one of the objects after detecting a measured pressure in the inner channel being lower than the predetermined pressure), the vacuum nozzle moves towards a substantially flat support surface, thereby pressing the held object against said support surface. I n such an embodiment the substantially flat surface of the object is aligned with the substantially flat support surface. This can be useful for further processing steps of the object in case the object was not perfectly aligned according to the predefined orientation.

Preferably, the vacuum nozzle holding the object is moved towards the support surface along an axis substantially perpendicular to the support surface.

I n a further preferred embodiment, after removing the vacuum nozzle from the recipient holding the object in the preferred orientation and aligning the substantially flat surface of the object with the substantially flat support surface, the vacuum nozzle provides the object at a position on the supporting surface comprising an aperture through the supporting surface, wherein said aperture comprises a lower diameter than that of the substantially flat surface of the object, wherein the aperture is an inlet to an enclosure. After this step a predetermined pressure is applied within the enclosure that differs from the outside pressure. The pressure within the enclosure is measured after a certain period with a pressure measuring means. In such an embodiment the measured pressure is compared to the predetermined pressure and the orientation of the object is considered to be successfully verified to be the predefined orientation when the measured pressure and the predetermined pressure are comparable.

I n a most preferred embodiment, the picked object is transported back to the recipient using the vacuum nozzle when the verification of the orientation fails. In such an embodiment objects that are after verification not perfectly aligned according to the predefined orientation are entered again in the recipient for a next try. Exam pies

The present invention will now be further exemplified with reference to the following example(s). The present invention is in no way limited to the given examples or to the embodiments presented in the figures.

Example 1 : Prior Art device 1

Figure 1 - Prior Art shows an axial cross-sectional view of a prior art vacuum nozzle relating to US20150015877. The vacuum nozzle 110a exists out of a tube 702 with an inner channel 704. The inlet is indicated with 708. In this particular vacuum nozzle, the inner channel is partially blocked from the inlet by the obstruction 706 for purposes that are not relevant for this invention. Because the inlet 708 must still be connected with the channel 704, the obstruction 706 is supported by discrete arms 710 extending laterally from the tube 702.

The vacuum nozzle 110a is used to pick gemstones for inspection. The inlet 708 has side walls that are falling inwards towards the bottom of the vacuum nozzle 110a. At the bottom the inner sides of the side walls are also falling inwards, but towards the inner channel. This suggests that the gemstones are supposed to be picked by the vacuum nozzle 110a with the pyramidally shaped end (pavilion) of the gemstone in the inlet 708. The intended orientation of the gemstone is in fact the opposite. The substantially flat surface (table) of the gemstone should be parallel to the obstruction 706. The particular shape of the side walls is to hold the crown below the table of the gemstone. The prior art document US20150015877 mentions itself that the gemstones can be picked by the vacuum nozzle 110a such that a point (pavilion) or corner is inserted in the inlet 708.

Example 2: Prior Art device 2

Figure 2 - Prior Art shows a view of an alternative prior art vacuum nozzle relating to US20150015877. The vacuum nozzle 810 has a generally flat bottom face 870 with a plurality of apertures 871 instead of the single inlet 708 of the vacuum nozzle 110a of the previous example.

The vacuum nozzle 810 is also intended for picking up gemstones for inspection. The drawback of the vacuum nozzle 110a of the previous example that it is possible that gemstones were picked by the vacuum nozzle 110a such that a point (pavilion) or corner is inserted in the inlet 708 is overcome by replacing the side walls buy a generally flat bottom face 870 with in this example a central aperture and six arranged in a hexagon around the single central aperture. The effect of this is to force an orientation of the gemstone picked up by the vacuum nozzle 810 that aligns a flat face, preferable the table, with the apertures of the nozzle.

Example 3: Markina of diamonds with a laser

In this example the current invention is used to pick diamonds from a recipient and to transport the diamonds to a flat surface on which the diamonds will be marked on the substantially flat surface (table) with a laser.

This example refers to Figure 3, Figure 4, Figure 5 and Figure 6. The dimensions on the figures and the ratios thereof do not necessarily represent actual dimensions and ratios. Figure 3 shows a bottom view of a nozzle of an embodiment of the present invention. Figure 4 shows schematically the attraction of an object in the inlet according to the predefined orientation. Figure 5 shows schematically the attraction of an object in the inlet according to the opposite orientation. Figure 6 shows schematically how the orientation of a diamond can be verified.

The diamonds 3 are stored in an open recipient. The vacuum nozzle 1 is submerged in the recipient. The inlet 2 of the vacuum nozzle 1 is below the top level of the diamonds in the recipient. The vacuum nozzle 1 is moved in two horizontal directions, perpendicular to each other, in order to cover the whole surface of the recipient during the picking process. It is clear that an alternative solution to cover the whole surface of the recipient is to move the recipient in two perpendicular directions relative to the vacuum nozzle 1 .

The pressure in the inner channel 4 of the vacuum nozzle 1 is lowered to a pressure below the atmospheric pressure outside the vacuum nozzle 1 . When a diamond 3 is coming close to the inlet 2, the diamond 3 will be attracted to the inlet 2. The diamond 3 can touch the inlet 2 with the substantially flat surface 5 of the diamond 3 (table). The grooves 6 in the mantle 7 of the vacuum nozzle 1 will not be closed and air can still flow from outside the vacuum nozzle 1 through the grooves 6 into the inner channel 4. This situation is depicted in Figure 5. The arrow at the top indicates the airflow created by the pressure control means to create a pressure in the inner channel 4 that is lower than the atmospheric pressure. The arrows at the bottom indicate how air can still flow from outside the vacuum nozzle 1 through the grooves 6 into the inner channel 4. The pressure inside the inner channel is measured with a pressure measuring means 8, e.g. a manometer.

However, when the pyram idally shaped end 9 of the diamond 3 (pavilion) enters the inlet 2, the grooves 6 are substantially blocked at the inside of the inlet 2 by the diamond 3. No air can flow into the inner channel 4 and the manometer 8 will measure a drop in the pressure in the inner channel 4. This situation is depicted in Figure 4. The arrow at the top indicates the airflow created by the pressure control means to create a pressure in the inner channel 4 that is lower than the atmospheric pressure. The pressure inside the inner channel is measured with a pressure measuring means 8, e.g. a manometer. The pressure in the inner channel is more than 500 mbar lower than the atmospheric pressure outside the inner channel.

The diamond 3 cannot enter the inlet 2 with the table 5 first because the dimensions of the inlet 2 are smaller than the dimensions of the table 5. The grooves 6 are too deep to have a successful substantial blockage of the grooves 6 in case not the pavilion 9 but one of the other corners of the diamond 3 enters the inlet 2. When the measured pressure is below the predeterm ined threshold, the device detects a successful pick of a diamond 3 and the vacuum nozzle 1 is removed from the recipient.

To facilitate the blockage of the grooves by the diamond 3, the inlet 2 has a chamfer 10 at the inside of the inlet 2. The chamfer is created at an angle between 30 and 50 degrees between the inlet 2 and the first end of the vacuum nozzle 1 .

The movements of the vacuum nozzle 1 or the recipient relatively with respect to each other are not only required to cover the whole surface of the recipient during the picking process, but it will also help to change the orientation of the diamonds 3 according to the predefined orientation with the pavilion 9 towards the inlet of the vacuum nozzle 1 . Due to the movements of the recipient the diamonds 3 will shake or the diamonds 3 can be pushed over by the vacuum nozzle 1 , and the diamonds 3 can tip over to rest on their table 5. It is also possible that the recipient is making fast movements with a small amplitude along one, two or three axis to shake the diamonds 3 and that the vacuum nozzle 1 is making slower and longer movements compared to the movements of the recipient to find and pick up the diamonds 3.

During the picking process the number of diamonds 3 in the recipient will decrease, what could result that some parts of the bottom of the recipient are not any longer covered by diamonds 3. This will slow down the picking process. To guarantee that still a sufficient number of diamonds 3 are offered to the inlet 2 of the vacuum nozzle

I , the recipient can be rotated around an axis in the horizontal plane. Gravity will cause the diamonds 3 to sink to the lowest part of the recipient. The area that needs to be covered by the vacuum nozzle 1 to find and pick the diamonds 3 can be limited to this bottom part of the recipient. An alternative is to use a bowl-shaped recipient. Gravity will always assure that the diamonds 3 are at the bottom part of the bowl, without the need to rotate the recipient around an axis in the horizontal plane.

When the device successfully picked a diamond 3, it is possible that although the pavilion 9 of the diamond 3 is inside the inlet 2 of the vacuum nozzle 1 , the table 5 of the diamond 3 is not perfectly aligned with the surface on which the diamond 3 will be placed to be marked with the laser. In a next step, the vacuum nozzle 1 will be transported to a substantially flat surface 11 and the vacuum nozzle 1 will be lowered until the table 5 of the diamond 3 is pressed against the substantially flat surface 11. This will adjust the orientation of the diamond 3 slightly until the table 5 is aligned with the surface 11 .

At the position of the diamond 3, there is a small aperture 12 in the substantially flat surface 11. This aperture 12 is connected to an enclosure 13 below the flat surface 11. To verify the correct alignment of the diamond 3, the pressure in the enclosure 13 is changed to a predetermined value, different of the atmospheric pressure outside the enclosure 13, while the vacuum nozzle 1 is keeping the diamond 3 in place on top of the aperture 12. The enclosure 13 has a connection 15 towards means to change the pressure inside the enclosure 13. The means to change the pressure inside the enclosure 13 are not shown in Figure 6. The predetermined pressure can be higher or lower than the atmospheric pressure. A manometer 14 measures the pressure inside the enclosure 13 during a certain period of time. When the difference between the predetermined pressure and the measured pressure within the enclosure 13 is lower than a predefined threshold, the table 5 of the diamond 3 is correctly aligned with the substantially flat surface

I I , otherwise the aperture 12 would not be completely closed and the pressure inside the enclosure 13 would remain or quickly return to the atmospheric pressure.

When this verification of the alignment of the diamond 3 is also successful, the diamond 3 can be finally marked on the table 5 of the diamond 3 by the laser. If the verification fails, the diamond 3 could for instance be returned by the vacuum nozzle 1 to the recipient for another try, or the vacuum nozzle 1 could put the diamond 3 apart for further inspection.

Claims

CLAI MS

1. Device for picking up objects in a predefined orientation, said objects comprising a pyramidally shaped end and an substantially flat surface on the opposite end, comprising: a vacuum nozzle, said vacuum nozzle comprising a tube with an inner channel and enveloped by a mantle, said tube comprising an inlet at a first end of the tube, with said inlet being in connection with the inner channel; a pressure control means suitable for controlling the pressure within the inner channel of the vacuum nozzle; a transport means adapted for moving the vacuum nozzle in at least a first and second direction, said first and second direction not being parallel and preferably mutually perpendicular; and a pressure measuring means adapted for measuring a pressure in the inner channel of the vacuum nozzle, characterised in that the vacuum nozzle comprises: at least one, preferably two, three, four or more, radial groove at the first end of the tube, said radial groove extending fully through the mantle of the tube.

2. Device according to claim 1 , wherein the device is provided with a recipient suitable for holding a plurality of the objects in an open interior volume of the recipient, the interior volume of said recipient being accessible to the vacuum nozzle.

3. Device according to claim 2, wherein the recipient and vacuum nozzle are adapted for relative movements with respect to each other.

4. Device according to claim 1 -3, wherein the device is provided with a control system for controlling the relative movements with respect to each other of the recipient and vacuum nozzle and for controlling the transport means, said control system preferably being automated.

5. Device according to the preceding claims 1 -4, wherein the size of the surface of the inlet of the vacuum nozzle is smaller than the base of the object.

6. Device according to the preceding claims 1 -5 for picking up diamonds with a table and a pavilion and/or culet, said pavilion and/or culet comprising a plurality of facets, whereby the radial grooves are positioned in a pattern according to the facets of the pavilion and/or culet.

7. Device according to the preceding claims 1 -6, whereby the vacuum nozzle comprises at least three grooves, said grooves being positioned to define the vertices of a regular polygon.

8. Device according to the preceding claims 1 -7, whereby the mantle is chamfered internally at the inlet.

9. Method for picking up objects in a predefined orientation, said objects comprising a pyramidally shaped end and an essentially flat surface on the opposite end, from a recipient holding a plurality of the objects therein, said method comprising the steps of: a. applying a pressure in the inner channel that is lower than the atmospheric pressure outside of the vacuum nozzle; b. inserting the inlet of the vacuum nozzle in the recipient to a level below that of the objects, whereby said vacuum nozzle comprises a tube with an inner channel and enveloped by a mantle, said tube comprising an inlet at a first end of the tube, and the inlet being provided with at least one, preferably two, three or more, radial groove at the first end of the tube, said radial groove extending fully through the mantle of the tube; c. measuring the pressure inside the inner channel; whereby the vacuum nozzle is removed from the recipient upon detection of a measured pressure below a predetermined pressure threshold that is lower than the atmospheric pressure.

10. Method according to claim 9, comprising a step of relatively moving the recipient and the vacuum nozzle with respect to each other after inserting the inlet of the vacuum nozzle in the recipient, and at least up until the detection of the measured pressure in the inner channel being lower than the predetermined pressure threshold.

11. Method for picking up objects in a predefined orientation according to any one of the preceding claims 9 to 10, further comprising the step of: moving the vacuum nozzle holding the object after detecting a measured pressure in the inner channel being lower than the predetermined pressure threshold towards a substantially flat support surface, thereby pressing the held object against said support surface and aligning the substantially flat surface of the object with the substantially flat support surface.

12. Method for picking up objects in a certain orientation and verifying the orientation according to claim 11 , wherein the vacuum nozzle provides the object at a position on the support surface, which support surface comprises an aperture through the support surface, wherein said aperture comprises a lower diameter than that of the substantially flat surface of the object, wherein the aperture is an inlet to an enclosure; said method comprising the following steps: applying a predetermined pressure within the enclosure that differs from the outside pressure; measuring the pressure within the enclosure with a pressure measuring means; comparing the measured pressure with the predetermined pressure.

13. Method according to claim 12, wherein the associated object is transported back to the recipient using the vacuum nozzle when the verification of the orientation fails.

14. Method according claims 9-13, executed with a device according to claims 1 8