WO2013182223A1

WO2013182223A1 - Led module holder

Info

Publication number: WO2013182223A1
Application number: PCT/EP2012/060529
Authority: WO
Inventors: Antonietta Stucchi
Original assignee: A.A.G. Stucchi S.R.L.
Priority date: 2012-06-04
Filing date: 2012-06-04
Publication date: 2013-12-12

Abstract

A module holder (1), comprising a module holder body (2), which is adapted to allow the accommodation of an LED module (6), the module holder body (2) being provided with holes (3) for the fixing of the body (2) to a heat sink (4), the peculiarity of which consists in that the holes (3) accommodate elastic means (12) which are kept compressed by retention means (13) which are inserted and locked within the holes (3), the retention means (13) allowing the accommodation of screws (25) for mating the body (2) to the heat sink (4), a locking ring (30) being provided in order to lock the module within the body (2) and push it against the heat sink (4).

Description

LED MODULE HOLDER

The present invention relates to a module holder, particularly for LED modules.

More specifically, the invention relates to a module holder that has a high ease of mounting of the LED module and of reliability over time of the thermal join between the LED module and the heat sink.

As is known, the modules are intended to be fixed to a heat sink.

The LED module is constituted by a card on which are positioned the LED and a connector plus a cable, or just a direct cable, for connection to the power supply line, by a circular plastic body which can be at different levels of elevation, and by an aluminum plate on which is fixed a thermal interface material or TIM, which is intended to come into contact with a heat sink. The TIM must ensure a correct transmission of heat from the module to the heat sink, since the LEDs inside the module must never exceed a determined temperature.

In substance, therefore, the module holder must ensure that there is a good and long-lasting pressure between the TIM and the heat sink, and lastly that there is an adequate mechanical retention of the module itself.

The above mentioned LED modules are generally of the type with an external power supply and do not run on mains voltage.

Currently, conventional LED modules are fixed to the module holder to the heat sink by way of screws which are arranged on the outer part of the module and which also ensure the correct pressure between the TIM of the module and the heat sink.

This solution has a number of drawbacks which are due to the fact that the tightening of the screws for fixing the module occurs on the plastic body of the module, with the risk of deforming it or breaking it during fixing or over time during operation.

Moreover, the solution of tightening with screws has some drawbacks which are due to the fact that following a possible yielding and reduction in thickness of the TIM with the passing of time, the screws do not make it possible to compensate for this yielding, with the consequence of a rise in the temperature of the LEDs and thus a reduction of the lifetime of the LED module.

Lastly, the substitution of the module must be carried out by a specialist technician and moreover the module that is substituted might not be mounted correctly if all of the screws are not tightened correctly and the pressure on the TIM is not uniform.

In order to try to ensure a correct substitution of the module, it is moreover necessary to use a dynamometric screwdriver for the correct tightening torque.

The aim of the present invention is to provide a module holder, particularly for LED modules, that makes it possible to ensure a good and long-lasting pressure between the TIM and the heat sink, by compensating for the yielding of the TIM over the lifetime of the LED module.

Another object of the present invention is to provide a module holder, particularly for LED modules, in which when locking the module to the TIM it is possible to apply a uniform pressure.

Within this aim, an object of the present invention is to provide a module holder in which the substitution of the LED module can be carried out without using a dynamometric screwdriver in order to determine the correct tightening torque.

Another object of the present invention is to provide a module holder that can keep in position, before the locking thereof, by way of adapted keys.

Another object of the present invention is to provide a module holder that can enable the removal of the LED module without using tools.

Another object of the present invention is to provide a module holder, particularly for LED modules, that is highly reliable, easily and practically implemented and low cost. This aim and these and other objects which will become better apparent hereinafter are achieved by a module holder, particularly for LED modules, comprising a module holder body, which is adapted to allow the accommodation of an LED module, said module holder body being provided with holes for the fixing of said body to the heat sink, characterized in that said holes accommodate elastic means which are kept compressed by retention means which are inserted and locked within said holes, said retention means allowing the accommodation of screws for mating said body to said heat sink, and in that it comprises a locking ring, which is adapted to lock said module within said body and push it against the heat sink.

Further characteristics and advantages of the present invention will become better apparent from the description of some preferred, but not exclusive, embodiments of the module holder according to the present invention, which are illustrated by way of non-limiting example in the accompanying drawings wherein:

Figure 1 is an exploded perspective view of the module holder according to the present invention according to a first embodiment, with the locking ring having an outer knurling in order to assist its rotation;

Figure 2 is an exploded perspective view of the module holder according to the present invention, in accordance with a second embodiment, with the locking ring having two tabs;

Figure 3 is a transverse cross-sectional view of the module holder shown in Figure 1 , with the locking ring not rotated;

Figure 4 is a transverse cross-sectional view of the module holder of

Figure 1 , shown in the condition where the screws that fix it to the heat sink are tightened, with the locking ring rotated and with the LED module compressed;

Figure 5 is a perspective view of a first variation of the module holder according to the present invention, with an opening; Figure 6 is a perspective view of a second variation of the module holder according to the present invention, with three openings;

Figure 7 is a perspective view of a first embodiment of locking ring;

Figure 8 is a perspective view of a second embodiment of locking ring, similar to the one shown in Figure 2;

Figure 9 is a perspective view of the mating between the module holder and the heat sink, with the LED module version with pin connector;

Figure 10 is a perspective view of the module holder according to the invention, with the LED module version with cable attached; and

Figure 11 is a perspective view of the LED module adapted to be used in the module holder according to the invention.

With reference to the figures, the module holder according to the invention, generally designated with the reference numeral 1, comprises a module holder body 2, made in a single piece, for example made of plastic material, and provided with a plurality of holes, for example three, which are designated with the reference numeral 3, for the fixing of the module holder body to a heat sink 4.

The LED module 6 can have, integral with it, at least one pin connector 5 for electrical connection to a socket connector with cable.

As an alternative, the LED module 6 can be provided with a cable that exits directly from the module, for the electrical connection.

Both of these versions of the LED module 6 are of the type with external power supply and accommodate within them the various LEDs which are adapted to supply the illumination.

The lower surface of the LED module 6 is covered by a layer of so- called TIM material 8 which is intended to come into contact with the upper surface of the heat sink 4.

The module holder according to the invention comprises moreover a locking ring 30 which is adapted to lock the LED module 6 within the body 2. The locking ring 30 is provided, at the face that lies opposite the one for locking against the LED module, with a pair of tabs 31 which are adapted to facilitate the rotation of the locking ring 30.

Another version of the locking ring 30 is provided, at its perimetric rim, with grooves 36 in order to facilitate the grip on the locking ring 30 and the consequent rotation of the locking ring.

The locking ring 30 can be moreover provided with at least one retention tooth 32, and preferably a pair of teeth which are adapted to retain the LED module 6 when the module is inserted into the body 2 and to still allow the rotation of the locking ring 30 even when the LED module inserted into the body 2 can no longer rotate.

These teeth, after the snap-acting insertion of the LED module into the locking ring, retain the module during the step of insertion of the LED module into the module holder body or the step of removal from the module holder body, such steps therefore being easy to execute even when the module holder is fixed downward and the LED module would tend to fall out of the module holder body.

The retention teeth 32 act on a recess 33 with an undercut 34 defined along the perimetric rim of the LED module 6.

The module holder ring 30 is provided moreover with a depressed portion 41 which is arranged circumferentially around the collar of the LED module 6, which enables a pushing action of the locking ring 30 on the upper part 8 of the LED module 6, pushing it toward the heat sink.

The depressed portion 41 is adapted to enable a pushing action of the locking ring 30 through the upper part 42 of the collar, which has no teeth, on the LED module 6.

The module holder body 2 is provided with at least one opening 35 for a connector, for the passage of cables 40 and for removing the LED module 6 with the fingers, without the use of tools, or with a tool.

Moreover, the body of the LED module can be provided with tabs 23 that protrude (outward or toward the inside of the module) radially and which make it possible to prevent the rotation of the LED module 6 once this is accommodated within the body 2, and make it possible to define the modules in accordance with the power levels or lumens, thus preventing their interchangeability.

Conveniently, the module holder body, 2, is provided with regions 10 for supporting pins 7 of the locking ring 30. The regions 10 are defined by a flat area, i.e. an area substantially parallel to the upper and lower faces of the module holder and preceded by an inclined plane 11 which thus makes it possible, once the locking ring 30 is accommodated inside the cavity of the module holder, and subsequent to the rotation of the locking ring 30, to bring the pins 7 into contact with the inclined planes 11.

This thus makes it possible, thanks to the passage along such inclined planes 11 with a rotation of the locking ring 30, to position the pins 7 at the regions 10, thus effecting a compression of the LED module 6 downward and thus toward the heat sink 4.

In this manner, the surface of TIM material 8 is brought to adhere and compress against the upper face of the heat sink 4, at the same time allowing a lifting of the module holder body 2, due to the presence of elastic means which are described below.

An optional step 22 placed between each inclined plane 11 and the corresponding flat portion 10 makes it possible to introduce a click in order to prevent the reverse rotation of the locking ring 30 during the operation.

In particular, the module holder body 2 is provided with elastic means 12, for example springs, which are adapted to be inserted into the holes 3 and inside such elastic means there being inserted rivets 13 which make it possible to lock the elastic means 12 within the holes 3, thus keeping them partially compressed.

Figure 2 shows the positioning of a rivet 13 within the hole 3 of the module holder body 2, with the upsetting of the rivet at the lower region of the module holder body, and thus the positioning of the elastic means 12 in the partially compressed state.

The upsetting of the rivet 13 makes it possible to render both the rivet 13 and the corresponding elastic means 12 captive, once the module holder body 2 is disconnected from the heat sink 4, at this point the screws 25 must be inserted into the body of the rivet and will then be screwed into corresponding holes 16, which are defined on the upper face of the heat sink 4.

The screw 25 which is used to screw the module holder body 2 to the heat sink 4 can be a standard, conventional screw.

Figure 2 shows the second embodiment of the module holder according to the invention where into the hole 3 a washer 15 is inserted on which the spring 12, into which the rivet 13 is then inserted, rests.

In this case, as shown in Figure 4, the washer 15 acts as an abutment and supporting element for the spring 12.

Operation of the module holder according to the invention is as follows.

The module holder body 2 is fixed with three standard screws to grip the heat sink 4 and the lower face of the module holder body 2 can be in contact with the heat sink 4.

When the module 6 is inserted in the module holder body 2, by way of clamping exerted by the locking ring 30, the module holder body 2 is lifted with respect to the plane of the heat sink 4, thus compressing the springs 12 that push the upper surface of the rings 8 or 34 of the module 6 against the heat sink 4, thus ensuring the required pressure.

The lifting movement of the body 2 of the heat sink is determined by the sliding of the three pins 7, which are integral with the locking ring 30, on the three inclined planes 11 which are defined in the module holder body 2 (as disclosed in patent application no. MI2008A00559 in the name of the same applicant of the present application). In this manner the pressure between the surface TIM 8 of the module 6 and the heat sink 4 is uniform since it follows the vertical movement of the LED module 6, even if the surface of the body is reduced in thickness over time, thus making it possible for the module holder body 2 to maintain a uniform distribution of the pressure over the surface of the TIM.

Moreover, with the module holder according to the invention, when the LED module 6 is completely inserted, the module holder body 2 is lifted with respect to the heat sink 4. This makes it possible to ensure better circulation of the air around the base of the LED module 6, thus favoring the dissipation of heat and thus preventing overheating.

The presence of a washer 15 makes it possible to better distribute the pressure on the plastic body 2 of the module holder.

The upsetting of the free part of the rivet 13 makes it possible to render the spring 12 captive, to the advantage of the installation and disassembly of the module holder according to the invention.

In practice it has been found that the module holder according to the present invention fully achieves the intended aim and objects, in that it makes it possible to render the springs captive within the module holder body, to be able to fix the module holder to the heat sink with standard screws and not with special screws, to ensure a uniform pressure between the LED module and the heat sink, to be able to tighten the screws for fixing the module holder to the heat sink without discharging the screws on the plastic body and thus deform it or break it during the fixing, to maintain a space between the lower face of the module holder body and the upper face of the heat sink, thus ensuring a good circulation of air in order to prevent the overheating of the module holder and of the corresponding LED module, to allow a removal of the LED module even without the use of tools, and to ensure an adequate mechanical retention of the module.

The module holder thus conceived is susceptible of numerous modifications and variations, all of which are within the scope of the appended claims. Moreover, all the details may be substituted by other, technically equivalent elements.

In practice the materials employed, as well as the contingent dimensions and shapes, may be any according to requirements and to the state of the art.

Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly, such reference signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference signs.

Claims

1. A module holder (1), particularly for LED modules, comprising a module holder body (2), adapted to allow the accommodation of an LED module (6), said module holder body (2) being provided with holes (3) for the fixing of said body to a heat sink (4), characterized in that said holes (3) accommodate elastic means (12) which are kept compressed by retention means (13) which are inserted and locked within said holes (3), said retention means (13) allowing the accommodation of screws (25) for mating said body (2) to said heat sink (4), and in that it comprises a locking ring (30), which is adapted to lock said module within said body (2) and push it against the heat sink.

2. The module holder according to claim 1, characterized in that said locking ring (30) has, at the face that lies opposite the one for locking against said body, a pair of tabs (31) which are adapted to facilitate the rotation of said locking ring (30).

3. The module holder according to claim 1, characterized in that said locking ring (30) is provided, at its perimetric rim, with slots (36) to facilitate the grip on said locking ring (30) and the consequent rotation of said locking ring (30).

4. The module holder according to one or more of the preceding claims, characterized in that said locking ring (30) is provided with at least one retention tooth (32), which is adapted to retain said LED module (6) when said module is inserted in said body (2) and to still allow the rotation of said locking ring (30), said at least one retention tooth (32) acting on a recess (33) with an undercut defined along the perimetric rim of said LED module (6).

5. The module holder according to claim 1, characterized in that said locking ring (30) is provided with a depressed portion (41) which is arranged circumferentially around a collar of said locking ring (30), said depressed portion (41) being adapted to allow a pushing action of said locking ring (30), through the upper part (42) of the collar, on said LED module (6).

6. The module holder according to one or more of the preceding claims, characterized in that said body (2) of the module holder is provided with at least one opening (35) for a connector, for the passage of cables (40) and for removing said LED module (6) with one's fingers or with a tool.

7. The module holder according to claim 1, characterized in that said retention means (13) comprise a rivet which is adapted to be inserted in said hole (3), inside said elastic means (12) and upset at the end that lies opposite the insertion end in order to ensure that the elastic means (12) are captive.

8. The module holder according to claim 1, characterized in that it comprises, at the region of accommodation of said LED module (6), and in order to allow the accommodation of said LED module (6), inclined planes (11) which are adapted to allow the locking by rotation of said locking ring (30) within the body (2) of the module holder, said inclined planes (11) being each joined to a plane (10) which is substantially parallel to the upper face and to the lower face of the body (2) of the module holder.

9. The module holder according to one or more of the preceding claims, characterized in that said rivets (13) are adapted to allow the insertion of screws (25) for the fixing of said body (2) of the module holder to the upper surface of said heat sink (4).

10. The module holder according to one or more of the preceding claims, characterized in that it comprises a step (22) between said inclined planes (11) and said planes (10).