The invention relates to a lamp socket for supporting a light source provided with an LED, the lamp socket including a cooling element and a socket housing, which includes socket contacts for electrically connecting the LED, and a lamp base which supports an LED connected to a heat conducting element and which is insertable into the socket housing and includes base contacts, which are electrically contactable through the socket contacts through a contact force in order to supply the LED with power, wherein the cooling element on the socket side is connected with the thermally conductive element on the LED side—possibly through a device that promotes heat transfer, such as thermally conductive foil or thermally conductive paste—with a contact pressure that promotes heat transfer, wherein the contact pressure is provided through a contact force produced through a suitable device in order to absorb heat generated by the LED during operations.
Lamp sockets of this type are known in the art. They are typically configured as compact fluorescent lamp sockets and lamp bases, wherein the lamp base is inserted into the socket and fixated through a rotation like a bayonet. Differently from fluorescent tubes, these configurations are designated as one side socket systems. Through the rotation, furthermore the socket and base contacts are connected with one another and the lamp is electrically contacted. This locking principle is also known as twist lock system. Lamp sockets are also known in the art in particular for light sources provided LEDs, where the base is inserted parallel to a surface of a cooling element, wherein this process also includes electrical contacting.
In the art it was the object of a lamp socket and a lamp base to mechanically support and electrically contact the lamp.
The service life of illuminants based on LEDs, however, depends from an optimum dissipation of the heat generated during operation of the LED. LEDs are particularly temperature sensitive. Therefore, lamp bases of this type include a heat conducting element which contacts a cooling element arranged at the socket. It is evident that a particular contact pressure between heat conducting element and cooling element positively influences heat transfer. Thus, sockets and bases for a light source including at least one LED are characterized in that besides the mechanical support and the electrical support, optimum heat dissipation has to be provided. Thus, sockets and bases for LED illuminants with respect to their configurative requirements greatly differ from their equivalents for compact fluorescent lamps.
In arrangements of lamp socket and lamp base according to the prior art, it has become apparent that the contact pressure between a base side heat conducting element and a socket side cooling element is not the sole measure for the quality of the heat transfer. In spite of a contact pressure accordingly provided, many sockets cause premature aging of the LEDs. Tests have shown that an even distribution of the contact pressure over the contact surfaces of heat conducting element and cooling element determines the quality of the heat transfer.
Thus it is the object of the invention to provide a lamp socket and a lamp base which provide evenly distributed contact pressure over a contact surface between heat conducting element and cooling element.
The object is achieved by a lamp socket and a lamp base with a cooling element, a socket housing which includes socket contacts for electrically connecting a light source, and a lamp base which supports an LED connected to a heat conducting element and is insertable in the socket housing and includes base contacts which are connectable with the socket contacts through a contact force for providing power to the LED. The cooling element on a socket side is connected with the heat conducting element on a base side (optionally through a device that promotes heat transfer, such as heat conducting foil or heat conducting paste) through a contact pressure that promotes heat transfer. The contact pressure is provided through a pressing force produced through a suitable device in order for the cooling element to absorb heat generated by the LED during operation, and the electrical connection between the socket contacts and the base contacts is provided through a contact configuration and/or a contact support that does not provide forces opposite to the pressing force. In particular the object is achieved with the electrical contacting between the socket contacts and the base contacts is provided by configuring and/or supporting the contacts without an opposite force to the contact force.
The invention uses the finding that already small force components that are oriented against the contact force providing the contact pressure significantly change the pressure distribution. Based on this, the invention prevents electrical contacting in which the contact forces are oriented against the pressing force through appropriate configuration of socket and base contacts or their support in the socket housing or at the lamp base.
An embodiment is advantageous in particular which is characterized in that the contact force between the socket contacts and the base contacts includes a force component which is oriented transversal to the effective direction of the pressing force.
Alternatively, it is conceivable that the contact force between the socket contacts and the base contacts has a force component that is oriented in the effective direction of the pressing force and does not influence an even distribution of the contact pressure.
Both recited embodiments provide that the effective direction of the contact forces does not negatively influence the pressing force and an even distribution of the pressing force.
It is even conceivable that the contacting between the socket contacts and the base contacts is provided in a manner that increases the pressing force.
A particular embodiment provides that the base contacts are configured as contacts which protrude from the base towards the cooling element, in particular as contact pins, wherein the contact force between the socket contacts and the base contacts is oriented transversal to the effective direction of the pressing force.
As a supplement thereto, it can be provided that the base contacts are configured as contact clamps which support the base contacts, in particular support the contact pins between two contact arms. It is particularly advantageous that the contact clamps which receive the base contacts between one another provide secure electrical contacting.
Alternatively it is conceivable that the base contacts are configured as contacts laterally protruding from the base circumference, in particular contacts oriented transversal to an effective direction of the pressing force like, for example, flat blade contacts and the contact forces between the socket contacts and the base contacts have an identical effective direction as the pressing force. With an even distribution of the flat blade contacts over the base circumference, this embodiment does not negatively influence an even contact pressure distribution on the contact surfaces of the heat conducting element and the cooling element.
However, it is also conceivable to provide a contact arrangement in which contact forces are provided which are oriented against the effective direction of the pressing force without the contact forces that are negative with respect to the effective direction of the pressing force influencing the contact pressure between the heat conducting element and the cooling element. An embodiment of this type is characterized in that the socket contacts are configured as a contact clamp and receive the socket contacts, in particular the flat blade contacts between one another and the contact forces of the contact arms receiving the socket contacts between one another are oriented opposite to one another and are oriented parallel to the effective direction of the pressing force, wherein the socket contacts are supported floating in the socket housing parallel to the effective direction of the pressing force and/or the socket contacts are supported parallel to the effective direction of the pressing force and are supported floating in the lamp socket.
Eventually an embodiment is conceivable which is characterized in that contact fields are configured at the socket or at the base where the base contacts or the socket contacts contact, wherein the contact forces are oriented transversal to the effective direction of the pressing force.
Further details and advantages of the invention are described based on embodiments with reference to drawing figures, where like numerals are used in for technically equivalent or identical components, wherein:
In the figures, an arrangement of lamp socket and lamp base is designated overall with the reference numeral 10.
A lamp socket 11 is illustrated which includes a cooling element 12 on which a socket housing 13 is arranged which is provided with socket contacts 14. The cooling element can also be an integral element, for example, of a lamp housing.
The surface of the cooling element 12 that is oriented towards the socket housing 13 is configured planar. The cooling element 12 is provided with a plurality of cooling ribs 15 on its bottom side arranged opposite to the socket housing 13 in order to increase the surface area and in order to improve heat dissipation.
The socket housing 13 includes a base receiver 16 which is configured in the present embodiment as a central circular recess. The lamp socket 17 includes optics 18 oriented away from the cooling element, wherein one or plural LEDs are arranged in a transition portion of the lamp base 17 and the optics 18. The lamp base 17 is configured in the embodiment with a contour that is congruent with the base receiver 16 and therefore configured as a circular cylinder. Support cams 19 radially protruding from the lamp socket 17 penetrate through locking grooves 20 when inserting the lamp base 17 into the socket housing 13 and reach behind accordingly configured wall sections of the socket housing 13 like a bayonet lock. In the first embodiment according to
In the arrangement 10 including the lamp socket 11 and the lamp base 17, the lamp socket 11 is considered as a lower component and the lamp base 17 is considered as an upper component.
As can be derived from
In
The lamp socket 17 supports a heat conducting element which is not designated in more detail which contacts on the one hand side the LED and when arranged in the socket 11 on the other hand side contacts the cooling element 12. This way, the heat generated through the operation of the illuminant is conducted away from the illuminant and dissipated through the cooling element 12 to the ambient. Thus it is required that the contact surfaces of the cooling element 12 and the base side heat conducting element contact one another with a particular minimum contact pressure. This minimum contact pressure is provided with a contact force which is generated by a device that is not illustrated. Typically, these are spring elements which load the lamp socket 11 and the lamp base 17 relative to one another. The contact pressure provides, possibly using additional devices improving heat transfer like heat transfer foil or heat transfer paste, a full surface even contact of the base side heat conducting element and the cooling element 12, and therefore provides optimum heat transfer.
In order to prevent negative influences upon the contact pressure or its even distribution through electrically contacting base and socket contacts, the invention provides solutions in the subsequently described embodiments, in particular with the described contact configuration and arrangement.
The socket contacts 14 configured as contact clamps 24 illustrated in
A second advantageous embodiment of the invention is illustrated in
A third embodiment of the invention is illustrated in
Another embodiment of the invention is illustrated in
Subsequently, the invention is also described in more detail with reference to
An arrangement of lamp socket and lamp base is illustrated which is overall provided with the reference numeral 40. The lamp socket 42 includes a cooling element 43, a socket housing which is not illustrated and socket contacts 44.
The lamp base overall designated with reference numeral 41 includes a base housing 45, wherein a heat conducting element 47 is arranged at the bottom side 46 of the base housing which is oriented towards the cooling element 43. The heat conducting element 47 contacts the cooling element 43 with a particular contact pressure FA, optionally with a heat transfer paste or a heat transfer foil arranged there between. The contact pressure FA is generated by a device which is not illustrated in more detail which can include, for example, spring elements which clamp the lamp base 41 together with the cooling element 43. In the embodiments according to
The even contact pressure that is generated through the contact force FA between the heat conducting element 47 and the cooling element 43 provides optimum transfer of the heat generated by the LED 49 during operation. Thus, the LED contacts the heat conducting element 47 supported in the base housing 45.
It is an important principle of the invention to configure the contact between the socket contacts 44 and the base contacts 50 through an appropriately selected contact configuration and/or appropriately selected contact support in the lamp base 41 or in the lamp socket 42 without an opposite force to the contact force FA. This means that the contact forces FK between the base contacts 50 supported by the lamp base and the socket contacts 44 which provide secure power supply for the LEDs do not have any force component which acts against the contact force FA.
The base contact 50 is oriented parallel to the effective direction of the contact force FA in a direction towards the cooling element 43. The contact arms 53 of the socket contact 44 are oriented in the same direction. The contact forces FK act substantially transversally to the pressing force FA.
An alternative embodiment is illustrated in
The embodiment of the invention illustrated in
The base contacts 50 protrude relative to the circumferential surface of the base housing 45, thus they are radially oriented. In particular they are flat blade contacts 56. These flat blade contacts 46 oriented transversal to the effective direction of the pressing force FA are contacted by the socket contacts 44 on a top sides of the flat blade contacts, thus on the side oriented away from the cooling element 43. Consequently, the effective direction of the contact forces FK is identical with the effective direction of the pressing force FA. In this embodiment, the contact forces FK therefore reinforce the contact pressure between the heat conducting element 47 and the cooling element 43 when the flat blade contacts 46 are evenly spaced along a circumference.
The last embodiment of the invention is illustrated in
As can be derived from
To sum it all up, the invention illustrates various contact configurations and contact arrangements of the socket and base contacts 44, 50, 14, 21 whose contact forces FK act without opposite force with respect to the pressing force FA. This is provided in particular in that the contacts are arranged relative to one another so that the contact forces are mostly aligned transversal to the pressing force or in the effective direction of the pressing force. However, when the contact arrangement includes a contact force component that is oriented against the effective direction of the pressing force, the contacts of the lamp socket 42, 11 and/or the lamp base 42, 17 have to be supported in a decoupled manner. Then this force component cannot develop an effect that is opposite to the pressing force FA.
Number | Date | Country | Kind |
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20 2009 010 577.6 | Aug 2009 | DE | national |
10 2009 040 115.6 | Sep 2009 | DE | national |
This application is a continuation of International application PCT/DE2010/000655 filed on Jun. 9, 2010 claiming priority from German application DE 20 2009 010 577.6 filed on Aug. 5, 2009 and German application DE 10 2009 040 115.6 filed on Sep. 4, 2009. All the above applications are incorporated in their entirety by this reference.
Number | Date | Country | |
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Parent | PCT/DE2010/000655 | Jun 2010 | US |
Child | 13360682 | US |