METHOD FOR MAKING A LAMP REFLECTOR DESCRIPTION

Field of the invention

The present invention relates to the field of lighting, and more in detail it relates to a method for making a lamp reflector, used for light projection coming from bright sources and made of bent sheet metal.

Furthermore, the invention relates to such a reflector.

Description of the prior art

Reflectors for light beams for lighting purposes are known. These reflectors are made starting from a single ply metal sheet, generally of aluminium, having a central portion from which thin metal sectors radially extend. Such sectors are bent up to form a required geometry of lamp reflector.

A lamp reflector of this type is described for example in US201 10246189A1 , where a locking ring, provided with teeth configured for engaging with cooperating grooves, is used after bending, in order to keep the metal sectors integral to each other.

During assembly of the lamp reflector, the teeth of the rings require to be precisely placed in the respective locking grooves of the sectors. Furthermore, the metal sheet sectors are only partially connected to the ring and, according to where the point of junction is made, they can move radially with subsequent possible deformation of the reflector and problems of mechanical stability. Furthermore, this kind of coupling has the disadvantage break of terminal edges of the sectors. All the above described deformations involve an alteration of light reflection by the inner surface of the reflector. The presence of the ring requires a further production step, with consequences on production time and costs.

US2014169002A1 provides an example of lamp reflector where metal sectors have a folding portion which allows, at the end of the sectors a portion that can be folded, obtaining a circumferential flange on which a locking ring is fixed by welding or gluing, in order to keep the sectors integral to each other.

Also in this case the presence of the ring causes a further production step, with consequences on production time and costs. However, since a small portion of the sectors is connected to the ring, also the above described reflectors are subjected to deformation, with a subsequent risk of mutual disengagement. Furthermore, the above cited devices are obtained with an high consumption of material, resulting from the cutting phase of the locking rings, and a high increase of production costs.

US6464378B1 shows an example of reflector, where the sectors are connected to each other by anchoring elements, without the need of a ring. However, the assembly step of such a lamp reflector is difficult and complex. In fact, the need for testing the correct joint of the anchoring elements requires manual assembly of the reflectors.

Summary of the invention

It is therefore a feature of the present invention to provide a lamp reflector for a lighting apparatus which is significantly less affected by deformation of sectors with respect to the known solutions.

It is another feature of the present invention to provide a lamp reflector for a lighting apparatus which has not the disadvantage of sectors separation of the prior art.

It is also a feature of the present invention to provide a lamp reflector for a lighting apparatus which significantly simplifies the production steps.

It is a further feature of the present invention to provide a lamp reflector for a lighting apparatus which can be obtained with less consumption of material.

It is also a feature of the present invention to provide such a lamp reflector which has parts for mounting the lamp reflector on a support for a lighting apparatus of simple construction.

These and other objects are achieved by a method for making a lamp reflector for lighting apparatus, the lamp reflector comprising a reflector body having:

- a lighting recess,

- a peripheral wall defining the lighting recess and having an outer face and an inner reflecting face,

- a base next to the peripheral wall, and

- a light outlet opposite to the base. The method comprising the steps of:

- prearranging a single ply metal sheet having a predetermined thickness and comprising a plurality of sectors extending from the base, the sectors having side edges,

- bending the sectors with respect to the base up to form the peripheral wall,

- keeping the edges of the sectors of the peripheral wall adjacent to each other, at the end of the bending step, in order to form adjacency lines with adjacent edges strictly in contact with each other, - welding the edges along the adjacency lines from the side of the outer face of the peripheral wall, in such a way that welding portions are obtained along the adjacency lines and so that welding portions do not alter the inner face of the peripheral wall.

This way, with respect to US201 10246189A1 , US2014169002A1 , US6464378B1 , joining the sectors by means of welding determines substantial continuity of material along the adjacency lines of the sectors, giving a uniform mechanical strength to the finished workpiece.

As disclosed in US201 10246189A1 or US2014169002A1 , or US6464378B1 , the present invention has the same advantage of starting from pre-cut metal sheets of different geometry. Furthermore, differently from the above described patent documents, the fact of welding the sectors to each other makes it possible to have less scrap and to obtain a lamp reflector body characterized by more stable connections. In particular, the absence of a ring allows saving much more material than the scrap of the single ply for making the reflector.

The above described structure of lamp reflector can be used for various geometries, as well as for the parabolic geometry described in US201 10246189A1 or US2014169002A1 , which requires a ring, or for the octagonal geometry described in US6464378B1 , which requires anchoring elements. In fact, according to the invention, since the edges of the sectors are mounted strictly adjacent to each other and welded to each other, there is the advantage of making any geometries of lamp reflector starting from single ply sheet portions having corresponding shape. This way, three-dimensional bodies of lamp reflector can be obtained for various applications.

Therefore, the reflector manufacturing processes, according to the invention, does not limit the obtainable reflector shapes and avoids deformation of the sheet sector portions.

Advantageously, said metal sheet has a thickness set between 0.4 and 0.7 mm and the welding portions are obtained by a step of micro-welding that involves, starting from the outer face, a welding depth of the sheet of the sectors less than 80% of said thickness, preferably less than 50%.

This way, since only very small portion of material is welded by means of laser welders, which are known to be highly efficient, the overall process for manufacturing the final workpiece can be very quick and fully automated, significantly reducing the production time. In other words, the invention provides a reflector, obtained starting from a thin single ply sheet which allows easy assembling, with excellent mechanical strength and durability.

Advantageously, the step of laser micro-welding is made with at least one welding characteristic selected from the group consisting of:

- diameter of the laser beam between 0.1 and 0.7 mm,

- power of the laser beam between 1 100 and 4000 W,

- pulsating laser with power of pulsation between 1 and 4 kW,

- pulsating laser with duration of pulsation between 3 and 50 ms,

- pulsating laser with frequency of pulsation between 0 and 50 Hz,

- pulsating laser with energy of pulsation between 0 and 25 J,

- or a combination thereof.

The reduced diameter of the laser beam incident on the welding surface makes it possible to obtain a welding portion that does not modify the aesthetical aspect of the manufactured article. Moreover, the diameter of the laser beam does not affect the welding region.

The step of keeping the edges of the sectors of the peripheral wall adjacent to each other, in order to form adjacency lines with adjacent edges strictly in contact with each other, avoids the portions of laser beam entering into the lighting recess. Such solution avoids obtaining poor quality or insufficient welding or damaging the inner face of the reflector. This way, the reflective efficiency of the reflector is preserved.

The fact that the power of the laser beam can be adjusted in a range set between 1 and 4Kw allows carrying out welded joints for different types of metal alloys.

The use of a laser having a pulsating waveform with frequency of pulsation set between 0 and 50Hz provides precision of the welding process, allowing, in the meantime, an advantageous energy dissipation control.

The power supply with pulsation laser and duration of pulsation set between 3 and 50 ms increases the melting depth of the welding portion.

The combination of pulsation waveforms and energy of pulsation set between 0 and 25 J allows setting up a welding program depending on the metal alloys subject to the laser melting process.

Advantageously, the step of keeping the edges of the sectors of the peripheral wall strictly adjacent to each other, in order to form adjacency lines with edges strictly in contact with each other can be obtained by a gripper that grips a portion of the side wall bringing the edges into strict contact with each other.

In particular, the gripper can provide a gripping force on the side wall. Such intensity is suitable for keeping the edges of the sectors strictly adjacent to each other without modifying the morphologic features of the reflector.

Advantageously, the laser can be conveyed, starting from a source, along the adjacency line by means of fixed mirrors and mirrors moved by galvanometers. The mirrors can convey the laser beam according to predetermined directions of propagation configured to follow portions of the adjacency lines, in such a way to obtain the sought welding portions.

This way, at least one or more than one mirrors can deflect the laser beam towards mirrors actuated by galvanometers. Precision and angular speed of galvanometers along its own axis allows the laser beam to be controlled at high speed. The energy of the laser beam is therefore distributed along the adjacency lines, in such a way to obtain a homogeneous welding along the welding portions.

Advantageously, the gripper that grips a portion of the side wall is configured to rotate around an indexing axis .

This way, the adjacency lines are selectively brought in a propagation plane containing the directions of propagation of the laser beam.

In particular, at the end of each welding portion, a motor, for example integrated in the gripper, allows rotation of the gripper around an indexing axis .

This way, separate welding portions are formed on adjacency lines.

Alternatively, a laser source is mounted on a robotic manipulator. In this case, the robotic manipulator can be oriented according to suitable planes arranged to project laser beams along the adjacency lines of the edges of the sectors in such a way to form the welding portions.

Preferably, the step of bending is obtained by a mould and a countermould. Advantageously, the mould can comprise inner gripping elements of a portion of the side wall. Furthermore, the mould can be capable of rotating about an indexing axis for bringing the adjacency lines selectively in a propagation plane containing the directions of propagation of the laser beams. Alternatively, welding laser beams can be obtained by a robotized laser.

The fact that the mould is configured to be used in the welding step by means of gripping elements configured to engage with a portion of the side wall, allows the automation of the whole production process to be facilitated. This way, deformation of the sectors is also avoided.

Gripping elements, which are comprised in the mould, can be equipped with retractable actuators that can be withdrawn during the moulding step, without interfering with the bending step, and which can face to the portions of side wall for the welding step. The gripping elements can apply a force on the sectors for keeping the edges integral to each other.

The fact that the welding step makes use of the same mould used in the previous bending step reduces the operating lifetime.

Gripping elements can be equipped with a suction element or they can be rubber coated cylinders, or of another type arranged for engaging with the area of interest without modifying the sectors' surface. The actuators that move the gripping elements can be electromagnetic actuators, pneumatic actuators, electric actuators, magnetic actuators, etc.

According to another aspect of the invention, a lamp reflector for a lighting apparatus comprises a reflector body having a lighting recess, the reflector body having:

- a peripheral wall defining the lighting recess, the peripheral wall having an outer face and an inner reflecting face,

- a base next to the peripheral wall,

- an outlet of the light opposite to the base.

The reflector body can be made starting from a single ply metal sheet having a predetermined thickness and comprising a plurality of sectors extending from the base, the sectors having side edges and being bent with respect to the base up to form the peripheral wall. According to the invention, the edges of the sectors of the peripheral wall are strictly adjacent to each other, in order to form adjacency lines with edges strictly in contact with each other and being welded starting from the outer face by welded joints along the adjacency lines, comprising welding portions along the adjacency lines, so that the welding portions do not alter the inner reflecting face.

Advantageously, the reflector body has the side wall with a geometry selected from the group consisting of: parabola, box-like shape, angle-shaped, starting from a single ply metal cut sheet.

This way, by different geometries, it is possible to have reflectors for many general lighting applications. For example, in the case of street light reflector, being the geometry of the reflecting face configured to increase the starting angle of the light beam, such reflectors can be positioned far from each other, for larger lighting areas.

Advantageously, the inner face has a surface with high reflective power. This way, a high intensity of reflected light is ensured.

In an exemplary embodiment of the invention, after the welding step along adjacency lines of the edges, a welding step of a connection element at the base of the reflector body can be provided. The connection element can be configured for a removable engagement of the lamp reflector with the lighting apparatus.

Such a solution, unlike the prior art, provides substantial continuity of material, at the base, between the connection element and the reflector.

This solution, also, increases the mechanical strength of the connection element. Advantageously, the step of welding the connection element at the base of the reflector body is obtained by a laser micro-welding step.

In particular, the laser micro welding step can be made with at least one welding characteristic selected from the group consisting of:

- diameter of the laser beam between 0.1 and 0.7 mm,

- power of the laser beam between 1 100 and 4000 W,

- pulsating laser with power of pulsation between 1 and 4 kW,

- pulsating laser with duration of pulsation between 3 and 50 ms,

- pulsating laser with frequency of pulsation between 0 and 50 Hz,

- pulsating laser with energy of pulsation between 0 and 25 J,

- or a combination thereof.

Such solution has similar advantages of the above described welding step for welding portions along the adjacency lines.

According to another aspect of the invention, a lamp reflector comprises a connection element arranged to engage the base of the lamp reflector with a support of the lighting apparatus. This connection element is engaged by welded joints with the reflector body at the base.

This solution avoids the use of fixing elements, which need a connection to the lamp reflector by lock joints, which could cause mechanical backlash due to coupling stresses between the connection element and the reflector, or which can cause complications during the assembling step.

Advantageously, the connection element comprises an external boundary, comprising engagement housings with the support, and an inner boundary, the base of the lamp reflector having a base boundary and the inner boundary of the connection element having a diameter larger than the base boundary, the inner boundary configured to self- centre on the base boundary, in particular the base boundary and the inner boundary are circular.

This way, the precise centring of the connection element with the lamp reflector increases the mounting precision of the lamp reflector axis with the lighting apparatus.

The fact that the inner boundary of the connection element has a diameter larger than the base boundary of the lamp reflector allows also simplifying the centring steps of the connection element on the lamp reflector during the welding step.

In particular, the welding step of the connection element can be done on the same machine that is arranged for welding of the edges of the sectors along the adjacency lines. In this case, the self-centring of the connection element that can be obtained thanks to the diameter, which is larger than the base boundary of the lamp reflector, allows welding on a same machine both the connection element and the sectors along the adjacency lines.

Brief description of the drawings

Further characteristic and/or advantages of the present invention will be made clearer with the following description of an exemplary embodiment thereof, exemplifying but not limitative, with reference to the attached drawings in which:

- Fig. 1 diagrammatically shows a perspective view of a lamp reflector according to the invention;

- Fig. 2 diagrammatically shows a top plan view of a single ply metal sheet for a reflector body, according to the invention, before the bending step;

- Fig. 3 diagrammatically shows a top plan view of a single ply metal sheet for a street light reflector, according to the invention, having four sectors, two of which are in central position and two are in lateral position, before the bending and welding steps;

- Fig. 4 diagrammatically shows a perspective view of a street light reflector, according to the invention, shaped starting from the single ply metal sheet of Fig. 3 after the bending and welding steps;

- Figs. 5A, 5B, show an exemplary embodiment of the single ply metal sheet described in Fig. 3, where two equal side sectors (Fig. 5B) are detached from a central body of Fig. 5A which comprises two central sectors;

- Figs. 5C, 5D show the single ply sheets of Figs. 5A and 5B, respectively after bending and before welding, configured in such a way to obtain the same reflector of Fig. 4;

- Fig. 6 diagrammatically shows a top plan view of a single ply metal sheet of a reflector, according to the invention, before the bending step;

- Fig. 7 diagrammatically shows a perspective view of a lamp reflector having a square layout, according to the invention, consisting of the single ply metal sheet of Fig. 6 after the bending and welding steps;

- Figs. 8A, 8B, 8C show respectively production process steps of a lamp reflector, comprising respectively the steps of prearranging a metal sheet, the cutting step and the bending step, according to the present invention; - Figs. 9A, 9B show possible welding procedures for the lamp reflector described in the present invention;

- Fig. 10 shows an example of gripper used to keep the edges of the sheets in contact to each other during the welding step;

- Fig. 1 1 shows a further example of method to keep the edges of the sheet integral to each other during the welding step;

- Fig. 12 shows an example of lamp reflector of the prior art, comprising a plurality of slots for receiving a connection element in such a way to anchor the lamp reflector to a support of the lighting apparatus;

- Figs. 13 and 13A diagrammatically show an exemplary embodiment of the invention comprising a lamp reflector and a connection element for a releasable engagement of the lamp reflector with the lighting apparatus;

- Figs. 14 and 14A diagrammatically show an exemplary embodiment of the invention comprising a connection element having different engagement housings with respect to the connection element described in Figs. 13, 13A;

- Fig. 15 shows, in a cross sectional view, the centring effect of the inner boundary of the connection element on the base boundary of the reflector;

- Fig. 16 shows a possible welding step of the connection element on the reflector.

Description of some preferred exemplary embodiments

With reference to Fig. 1 , according to the invention, a lamp reflector for lighting apparatus comprises a reflector body 1 10 having a lighting recess 1 1 1 in which a lighting body not shown can be placed, for example an incandescent lamp, a fluorescent lamp, or a LED.

The reflector body 1 10 comprises a peripheral wall 1 12 having an outer face 1 13 and an inner reflecting face 1 14, which defines the lighting recess 1 1 1 . Furthermore, the reflector body 1 10 comprises a light outlet 120 opposite to a base 130.

The peripheral wall 1 12 is obtained starting from a single ply metal sheet 200 (Fig. 2) having sectors 140 that extend radially from the base 130.

The parabolic shape of Fig. 1 is obtained after bending the single ply metal sheet 200. In particular, sectors 140 are kept strictly adjacent to each other and in contact along the edges 150, in order to form adjacency lines 160.

With the aim of keeping sectors 140 integral to each other, a welding step on the outer face of edges 150 is provided. In particular, micro-welded joints 161 are obtained on the outer face without altering inner face 1 14 and then its reflective feature. Welding portions 161 can be obtained by spot welding, as shown for example on the left of Fig. 1 , or by intermittent welding, as shown on the right side of Fig. 1 . Obviously, these welding procedures can be employed also for other reflective bodies different from that shown in Fig. 1 .

In particular, the metal sheet (for example a metal sheet 200 as indicated in Fig. 2) can have a thickness set between 0.4 and 0.7 mm and the welding portions 161 can be obtained by a step of micro-welding that involves, starting from the outer face 1 13, a depth of the sheet of the sectors less than 80% of said thickness, preferably less than 50%, as diagrammatically shown in the exemplary embodiment of Fig. 9A.

This way, it is obtained a lamp reflector with a reflector body 1 10 which is different from the examples described in the prior art for the presence of a welding process that joins sectors 140 along the adjacency lines 160 and which is responsible for the mechanical strength of the lamp reflector, also avoiding deformation of sectors 140.

In fact, in the advantageous case where sectors 140 are welded to each other for example by a process of laser welding without base metal, it is possible to save on the amount of material used. This way, it is possible to obtain a structure of lamp reflector for lighting apparatus lighter than the reflectors of the prior art, where the sectors 140 are joined to each other by means of rings or teeth.

The fact that the edges 150 of the sectors 140 are kept strictly adjacent to each other, in order to form adjacency lines 160 with edges strictly in contact to each other, and the fact that welding portions 161 are obtained along the outer side of the adjacency lines in order to not affect the inner face, avoids optical artefacts on the inner face 1 14, ensuring correct and homogeneous reflection of the light source through the inner face of the reflector.

With reference to Fig. 2, the single ply metal sheet 200 can be obtained, starting form a metal sheet, by means of cutting processes, such as blanking process. The single ply metal sheet shown in Fig. 2 has a circular geometry and comprises a plurality of thin sectors 140 of sheet metal that extend from the base 130. The edges 150 are the elements that in the following bending step are kept strictly in contact with each other, in order to form adjacency lines 160 of Fig. 1 .

With reference to Fig. 3, in a possible exemplary embodiment of the invention, it is diagrammatically shown a single ply metal sheet, for a street light reflector, according to the invention. Such single ply metal sheet comprises four sectors, two of which are in central position and two are in lateral position, before bending as shown in Fig. 4.

Sectors 140 and edges 150 of the single ply metal sheet shown in Fig. 3 have different geometry with respect to those of Fig. 2. Therefore, during mechanical cutting process, cutting dies will be employed having cutting edges with shape responsive to the single sought ply metal sheet profile.

Fig. 4 shows, according to a perspective view, an example of a street light reflector, where, similarly to the circular embodiment of Figs. 1 and 2, welding portions 161 extend along the adjacency lines 160.

Figs. 5A - 5D show exemplary embodiments of single ply metal sheets for forming sectors 140 for a street light reflector. In particular, Fig. 5A and 5B show respectively the single ply metal sheet of the central wall and side wall of a street light reflector. Advantageously, only a single side wall is shown. Figs. 5C and 5D shows the central wall and the side wall after the bending step. The edges 150 of each sector of each wall will be welded by welding portions to the corresponding edges of the sectors 140 of the respective wall in order to form a street light reflector. This way, by using a plurality of parts to form a single reflector, there are less working scraps with respect to a single ply metal sheet.

With reference to Fig. 6, in a possible exemplary embodiment of the invention, an example of a single ply metal sheet for a box-like reflector comprising a base 130, sectors 140 and edges 150 is shown. Fig. 7 shows a perspective view of an exemplary embodiment of a box-like reflector where, starting from the single ply metal sheet of Fig. 6, and after the bending step of sectors 140, welding portions 161 are obtained along adjacency lines 160.

Figs. 8A, 8B, 8C shows a possible exemplary embodiment of a production process starting from a thin metal sheet 700 (Fig. 8A), for example an aluminium sheet having thickness set between 0.4 and 0.7 mm. A cutting machine 160, for example a shearing machine, or a press machine, can exert a force 166 on the metal sheet 700 in such a way to form a single ply metal sheet (Fig. 8B). Alternatively, a laser or water cutting machine, or a milling machine can be used to cut the metal sheet according to a predetermined geometry in such a way to form a single ply metal sheet of a reflector.

Fig. 8C show an example of a bending process to obtain a peripheral wall 1 12 of a reflector. The peripheral wall 1 12 is obtained by a mould 180 and a countermould 170 configured to apply a pressing force 167 on a single ply metal sheet arranged between them.

The mould 180 can be provided with smooth inner walls. Alternatively, in an exemplary embodiment, mould 180 can comprise gripping elements 340. In particular, gripping elements 340 are placed within the mould 180 during the bending step and are configured to come out and to be pushed by actuators 341 , as extractors or lifting elements, during the welding step. The presence of the gripping elements 340, which are diagrammatically shown in Fig. 8C, does not modify the inner surface of the countermould.

With reference to Figs. 9A, 9B, in a possible embodiment of the invention, a welding step is described. Fig. 9A shows a welding zone comprised between two sectors 140. In particular, welding penetration can be for example 50% of the thickness, but can reach 80% of the thickness without damaging the inner reflecting face 1 14 of the reflector body 1 10 of Fig. 1 . Sectors 140 are joined to each other and kept in close contact during welding, according to arrows 210, for example by a force generated by a mould or a workpiece holder. Welding is performed by a laser beam 190, conveyed by a laser device 191 along adjacency line 160, which forms welding portions 161 moving along the adjacency line 160 according to the direction of arrow 220.

A laser beam 190 can be conveyed along the adjacency line 160, starting from the laser device 191 by means of fixed mirrors 231 and movable mirrors 230 actuated for example by galvanometers 260 (Fig. 9B). Movable mirrors convey laser beam 190 according to predetermined directions of propagation, in order to follow portions of the adjacency lines 160, in such a way to obtain welding portions 161 . In particular, precision and speed of galvanometers along its own axis allows orienting the laser beam at extremely high speed allowing a distribution of the laser energy along the adjacency lines. This way, it is possible to control the heat transfer avoiding bubble generation.

As shown in Fig. 10, the step of keeping the edges 150 of the sectors 140 of the peripheral wall 1 12 strictly adjacent to each other, in order to form adjacency lines 160 with edges strictly in contact with each other, can be made by a gripper 310 that grips a portion of the side wall 1 12. Gripper 310 is diagrammatically shown in the figure and can be made in any known way by a person skilled in making workpiece holders for welding machines. Gripper 310 can exert a force on the side wall 1 12 according to arrows 210. After welding each portion 161 , a motor 320 can cause gripper 310 to rotate about an indexing axis 321 for bringing a new adjacency line 160 of the lamp reflector in a propagation plane containing the directions of propagation of the laser beam 190.

Alternatively, the laser source of Fig. 9A can be moved by means of a robotic manipulator that moves around the welding piece.

With reference to Fig. 1 1 , the step of bending the lamp reflector 1 10 can be obtained by a countermould 170 and a mould 180, where the mould comprises inner gripping elements 340 for gripping a portion of side wall 1 12. Gripping elements 340 can be retractable by actuators 341 . In particular, during the bending step , grippers are hidden and the mould surface 180 is substantially smooth, while during extraction of the body 1 10 gripping elements 340 hold the reflector at a certain height. The mould 180 can be capable of rotating around an axis 321 by a motor 320 for bringing the adjacency lines selectively in a propagation plane containing the directions of propagation of the laser beam 190. Alternatively, the laser source can be moved by a robotic manipulator that moves around the welding piece.

The fact that the countermould is configured to be used during welding by means of gripping elements that engage with a portion of the side wall, facilitate the automation of the overall process, avoiding also undesired deformations of sectors 140 of the reflector body along for example a manipulation pathway from a bending station to a welding station. Gripping elements 340, which are comprised in the mould 180, have actuators 341 which can both withdraw during moulding, without interfering with the correct bending, and can protrude from the portion of side wall for the welding step. Moreover, gripping elements 340 can apply a force on the sectors 140 for keeping the edges joined to each other. Gripping elements can be equipped with suction elements or they can be rubber coated cylinders, or of another type that is capable of engaging with the area of interest without modifying the sectors 140 surface. The actuators that move gripping elements can be selected among electromagnetic actuators, pneumatic actuators, electric actuators, magnetic actuators.

With reference to Fig. 12 it is described an example of a lamp reflector for lighting apparatus used in the prior art and equipped with a related connection element 400.

In particular, the lamp reflector has a peripheral wall 1 12, a lighting recess 1 1 1 inside the peripheral wall 1 12 and a base 130 next to the peripheral wall 1 12.

The base 130 provides a plurality of slots 450, which are arranged radially and spaced from each other of 120°, configured for receiving pins 410 of the connection element 400, which is configured for connecting the lamp reflector to a support of the lighting apparatus. The connection element 400 can provide engagement housings 420, configured to engage with the support of the reflector (not shown), and connection pins 410, configured to be bent at 90° with respect to the plane of the connection element 400 in order to insert themselves into the slots 450 of the base 130 and to be secured, for example by glue or riveting.

Considering this prior art solution, the use of connection pins 410, which are foldable, for engaging slots 450 of the connection element 400 with the reflector, has the drawback of causing an unsteady connection with possible mechanical instability of the reflector, as well as structural and process related difficulties. With reference to Figs. 13 and 13A, it is described an exemplary embodiment of the invention comprising a connection element 400 configured to be joined at the base 130 of the reflector body 1 10. In the example of Fig. 13, the connection element 400 is a plane metal sheet comprising an opening 401 configured for receiving at least one light source.

The connection element 400 comprises, similarly to the prior art, three engagement housings 420, in order to allow, once connected to the lamp reflector in the way hereinafter described according to various embodiments of the invention, a releasable connection with the support of the lighting apparatus. Unlike the prior art, following the above described welding step as depicted in Figs. 9 to 1 1 , a step of welding a connection element 400 at the base 130 of the reflector body 1 10, in order to join the connection element 400 on the reflector body 1 10, is provided. As shown in Fig. 13A, the connection element 400 is joined with the connection element 400 by welding portions 131 at the base 130 of the lamp reflector.

In particular, the connection element 400 comprises an external boundary 405 and an inner boundary 406.

With reference to Figs. 14, 14A it is described an exemplary embodiment of the invention where the connection element 400 has engagement housings 420 for a bayonet fitting with the support. Other exemplary embodiments of the connection element 400 are possible, according to the structural needs of the reflector.

With reference to Fig. 15, it is described a possible advantageous centring solution on the basis 130 of the reflector by the inner boundary 406 of the connection element 400 illustrated in Figs. 13 or 14. In particular, connection element 400 comprises an inner boundary 406 and an external boundary 405 having engagement housings 420 for the support. The base 130 of the lamp reflector has a base boundary, and the inner boundary 406 of the connection element 400 has a diameter larger than the base boundary of the base 130. The inner boundary 406 is configured to self-centre the base boundary of the base 130. In particular, the base boundary of the base 130 and the inner boundary 406 are circular.

Alternatively, both the base boundary of the base 130 and the inner boundary 406 can be of various shape, for example square, rectangular, hexagonal, and the like, and configured to fit the base 130 within the inner boundary 406, in order to obtain a self- centring configuration.

With reference to Fig. 16, it is described a possible embodiment of the invention, where the connection element 400 is welded at the base 130 of the lamp reflector by a laser beam 190. In particular, as described in Figs. 9A, 9B, the laser beam 190 emitted by laser device 191 is conveyed by movable and fixed mirrors 230, 231 according to predetermined directions of propagation, in order both to follow the adjacency lines 160 and to obtain the welding portions 161 , and to follow the base 130 for the welding portions 131 execution. This way, both the welding of the connection element 400 at the basis 130 and the welding the edges of the sectors 140 along the adjacency lines 160 are provided on the same machine. In particular, this procedure is facilitated thanks to the above described self-centring feature of the connection element 400 as a result of the larger diameter of the base boundary 406 with respect to the basis 130 of the lamp reflector.

The foregoing description of some exemplary specific embodiments will so fully reveal the invention according to the conceptual point of view, so that others, by applying current knowledge, will be able to modify and/or adapt in various applications the specific exemplary embodiments without further research and without parting from the invention, and, accordingly, it is meant that such adaptations and modifications will have to be considered as equivalent to the specific embodiments. The means and the materials to realise the different functions described herein could have a different nature without, for this reason, departing from the field of the invention. It is to be understood that the phraseology or terminology that is employed herein is for the purpose of description and not of limitation.