Electric lamp with pin safety arrangement

Abstract

An electric lamp comprises a lighting module, a pin comprising an electric contact for powering the lighting module, and an insulating sleeve surrounding the pin and movable along the pin between a covering position and an uncovering position. Further, the sleeve covers the electric contact of the pin when in the covering position, and is retractable against the action of a biasing means to the uncovering position, in which the sleeve uncovers at least a portion of said electric contact of the pin.

Claims

1. An electric lamp comprising: a lighting module; a pin comprising an electric contact for powering the lighting module; and an insulating sleeve surrounding the pin and movable along the pin between a covering position and an uncovering position, wherein the sleeve covers the electric contact of the pin when in the covering position, and is retractable against the action of a biasing means to the uncovering position, in which the sleeve uncovers at least a portion of said electric contact of the pin, said lamp further comprising an externally-accessible activating member coupled with at least one end of the biasing means whereby manipulation of the activating member moves the biasing means along a longitudinal axis of the electric lamp, the activating member adjustable between a transport position, in which the activating member disconnects the pin and the lighting module, and a use position, in which the activating member connects the pin and the lighting module and allows the sleeve to move between said covering position and said uncovering position subject to the action of the biasing means.

2. A lamp as defined in claim 1, wherein the sleeve is mounted to a frame of the lamp via a spring forming said biasing means.

3. A lamp as defined in claim 1, wherein the biasing means is mounted to a frame of the lamp via the activating member.

4. A lamp as defined in claim 3, wherein the activating member is a rigid element movable along the frame of the lamp between the transport position and the use position.

5. A lamp as defined in claim 1, wherein the pin is adapted to be inserted in a lamp fitting and the sleeve is located in such manner that it is urged into its uncovering position by a surface of the lamp fitting upon insertion of the pin in the lamp fitting.

6. A lamp as defined in claim 1, wherein the sleeve is pushed into its covering position upon removal of the pin from a lamp fitting if the activating member is in its use position.

7. A lamp as defined in claim 1, wherein the sleeve is arranged to be at least partly contained inside a compartment of the lamp when in the uncovering position.

8. A lamp as defined in claim 1, wherein the tip of the pin is covered with an electrically insulating coating.

9. A lamp as defined in claim 1, wherein the lamp is a tube lamp comprising a plurality of LEDs.

10. A lamp as defined in claim 1, comprising a plurality of pins, each having a corresponding sleeve.

11. A lamp as defined in claim 10, wherein at least two pins of said plurality of pins are arranged parallel to one another and the sleeves associated with the at least two pins are rigidly interconnected.

12. A lamp as defined in claim 10, comprising at least two subgroups of pins, each comprising at least one pin of said plurality of pins, wherein sleeves within different subgroups are non-connected and independently movable.

13. The lamp of claim 1, wherein the biasing means comprises a spring to bias the insulating sleeve toward the covering position, the spring including a first end that is interconnected with the insulating sleeve and a second end opposite the first end, and wherein the activating member is interconnected with the second end of the spring.

14. A tube lamp comprising: a tubular housing; a plurality of LEDs arranged along a longitudinal axis of the tubular housing; at least two pins arranged parallel to each other, each comprising an electric contact to power the plurality of LEDs; at least two insulating sleeves, each surrounding one of the at least two pins, wherein the at least two insulating sleeves are rigidly interconnected by a support element; a spring interconnected to the support element at a first end; and an externally-manipulable activating member interconnected to a second end of the spring opposite the first end, the activating member manipulable between a transport position, in which the activating member disconnects the at least two pins from the plurality of LEDs, and a use position, in which the activating member connects the at least two pins to the plurality of LEDs; wherein manipulation of the activating member from the transport position to the use position moves the spring along the longitudinal axis in a direction towards the support element and transitions the support element into a covering position, in which the at least two sleeves cover the electric contacts of the at least two pins, wherein while in the covering position, the support element is moveable against bias of the spring to an uncovering position, in which the at least two sleeves uncover at least a portion of said electric contacts of the at least two pins.

15. The tube lamp of claim 14, wherein the spring and the externally-manipulable activating member are moulded as a single piece.

16. The tube lamp of claim 14, wherein the spring, the support element, and the externally-manipulable activating member are moulded as a single piece.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) This and other aspects of the present invention will now be described in more detail with reference to the appended drawings showing embodiments of the invention.

(2) FIG. 1 illustrates a safety risk arising when an LED tube lamp without any pin safety arrangement is installed in a lamp fitting;

(3) FIG. 2A is a schematic view of a lamp according to an embodiment of the present invention, with sleeves being in a covering position;

(4) FIG. 2B shows the lamp of FIG. 2A, but when the sleeves are in an uncovering position;

(5) FIG. 2C is a schematic view of a lamp according to another embodiment of the present invention, with an actuating member being in a transport position;

(6) FIG. 2D shows the lamp of FIG. 2C, but when the actuating member is in a use position;

(7) FIG. 3A is a cross-sectional view of lamp according to another embodiment of the present invention, with an actuating member being in a transport position;

(8) FIG. 3B shows the lamp of FIG. 3A, but when the actuating member is in a use position, and with sleeves being in a covering position; and

(9) FIG. 3C shows the lamp of FIG. 3A, but when the actuating member is in a use position, and with sleeves being in an uncovering position.

(10) All figures are schematic, not necessarily to scale, and generally only show parts which are necessary in order to elucidate the invention, wherein other parts may be omitted or merely suggested.

DETAILED DESCRIPTION

(11) FIG. 1 shows an LED tube lamp 1 which is being installed in a lamp fitting 13 by an installer 100. The lamp 1 is provided with pins 12 adapted to fit in the lamp fitting 13 for powering a lighting module 11 of the lamp 1. However, the lamp 1 shown in FIG. 1 is not provided with any pin safety arrangement. As the installer 100 has fitted one of the tube ends of the lamp 1 in the lamp fitting 13, the power converter and ballast for driving the lighting module 11 establish a current path through the lighting module 11. As the lighting module 11 is electrically connected to the pins 12 at the end of the lamp 1 exposed to the installer 100, these pins 12 will become live and the installer may be subject to an electric shock if he or she touches the pins 12 at the exposed end.

(12) With reference to FIGS. 2A-2D, a lamp according to embodiments of the present invention will be described.

(13) FIGS. 2A and 2B is a schematic view of an end of a lamp 2 provided with a pin safety arrangement. The lamp 2 comprises two pins 21 arranged at the end of the lamp 2, each having an electric contact (not shown) through which a lighting module (not shown) of the lamp 2 may be powered. The electric contacts may occupy a portion, or all, of the pins 21. For example, the pin 21 may be made of metal, whereby the whole pin 21 may form the electric contact. The lamp 2 further comprises two sleeves 22, wherein each sleeve 22 is arranged to surround its corresponding pin 21 in the azimuthal direction and be movable along the pin 21 in the axial direction. For example, each sleeve 22 may be formed of a tube shaped element threaded onto the pin 21. The sleeves 22 are made of an electrically insulating material, such as plastic or a ceramic material. Advantageously, the material may be selected to resist excess heat conducted from the lighting module. Preferably, the sleeves 22 are rigidly interconnected, e.g. by a supporting element 27. The sleeves 22 are supported in a frame of the lamp 2, via the supporting element 27, by a spring 23 acting as a biasing means. For the sake of simplicity, the spring 23 is schematically depicted as a coil spring in FIGS. 2A and 2B, but the spring 23 may be formed of any suitable resilient element, and is preferably made of an electrically insulating material, such as plastic, so as not to act as a short circuit if the spring 23 should come into contact with the pins 21 or any other electrically conducting part.

(14) FIG. 2A shows the lamp end when it is not inserted in a lamp fitting, wherein the sleeves 22 are urged by the action of the spring 23 into a covering position, in which they cover the distal portions of the pins 21. In this covering position, the electric contacts of the pins 21 are covered by the sleeves 22.

(15) FIG. 2B shows the lamp end when it is inserted in a lamp fitting 200, wherein the sleeves 22 are urged by a surface 201 of the lamp fitting 200 against the action of the spring 23 into an uncovering position. In this uncovering position, at least those portions of the electric contacts that have been inserted in the lamp fitting 200 are uncovered by the sleeves 22, and the sleeves 22 are contained in a compartment 28 formed at the end of the frame of the lamp 2.

(16) In an embodiment, the lamp 2 may further comprise an activating member 24, as schematically illustrated in FIGS. 2C and 2D. The activating member 24 may be set in a transport position, as shown in FIG. 2C, wherein the sleeve arrangement is deactivated. In its transport position, the activating member 24, which acts as a support for the spring 23, retains the sleeves 22 in their uncovering position while maintaining the spring 23 in a relaxed mode. Further, the activating member 24 may be set in a use position, as shown in FIG. 2D, wherein the activating member 24 activates the sleeve arrangement by moving the support for the spring 23 towards the end surface of the lamp frame, such that the sleeves 22 are in a covering position when the spring 23 is relaxed and can be urged into a covering position by the lamp fitting. Further details about the activating member and its positions will be described with reference to FIGS. 3A-3C.

(17) With reference to FIGS. 3A-3C, a lamp according to another embodiment of the present invention will be described.

(18) FIGS. 3A-3C are cross-sectional views of an end of a lamp 3 provided with a pin safety arrangement. The lamp 3 comprises a pin 31 made of metal (the lamp 3 may comprise two or more pins 31, but only one is shown in FIGS. 3A-3C), wherein the tip 36 of the pin 21 is covered with an electrically insulating coating, such as a plastic, rubber or ceramic coating. The coating may have been applied as an ink or in dry form. As the pin 31 is made of metal, an electric contact is formed by the portion of the pin not covered with insulating coating. The electric contact is adapted to conduct power to a lighting module (not shown) of the lamp 3.

(19) The lamp 3 further comprises an insulating sleeve 32 surrounding the pin 31 and movable along (the axial direction of) the pin 31. Advantageously, the length of the sleeve 32 may match (or correspond to), or be slightly longer than, the length of the portion of the pin 31 extending from the end surface of the frame of the lamp 3, such that the sleeve 32 is able to cover the whole length of this portion of the pin 31 extending from the end surface of the frame of the lamp 3. The remaining portion of the pin 31, which is contained inside the frame of the lamp 3, need not be covered by the sleeve 32. Further, the sleeve 32 is arranged on a support element 37, preferably made of an electrically insulating material. Preferably, the sleeve 31 and the support element 37 may be formed (such as moulded) in a single piece.

(20) The lamp 3 further comprises an activating member 34 movable in a slot 35 back and forth towards the end surface of the lamp 2, preferably in the axial direction of the lamp 2. The activating member 34 is interconnected with one end of the spring 33. The activating member 34 and the spring 33 may advantageously be formed in a single piece, preferably made of plastic, such as illustrated in FIGS. 3A-3C. The other end of the spring 33 is arranged to support the supporting element 37. Hence, the spring 33 interconnects the sleeve 31 and the activating member 34.

(21) According to an embodiment, the sleeve may be directly connected to the spring and the spring in turn may be directly coupled to the activating member (not shown). Preferably, the sleeve, the spring and the activating member may be made (such as moulded) in a single piece.

(22) Still with reference to FIGS. 3A-3C, the different positions of the activating member 34 and the sleeve 31 of the lamp 3 will now be described.

(23) FIG. 3A shows the lamp 3 when the activating member 34 is in a transport position, wherein it has been slid away from the end surface of the lamp frame. In this transport position, the sleeve 32 has been retracted into a compartment 38 formed at the end of the lamp frame, by the spring 33 and is in an uncovering position. Consequently, the sleeve uncovers the pin 31 and its electric contact. In this position, the spring 33 is in a substantially relaxed (non-tensioned) mode.

(24) In the transport position, the activating member 34 is further arranged to disconnect the pin 31 and the lighting module, thereby disabling a current path from the lighting module to the electric contact. This may e.g. be achieved by the activating member 34 controlling a switch (not shown) opening and closing the electric path between the pin 31 and the lighting module.

(25) FIG. 3B shows the lamp 3 when the activating member 34 is in a use position, wherein it has been slid towards the end surface of the lamp frame, whereby the sleeve arrangement is activated. As the activating member 34 is moved closer to the end surface of the lamp frame, the spring 33 will exert a force on the supporting element 37 towards the end surface of the lamp frame. If no counter force is exerted on the sleeve 32 against the action of the spring 33, the supporting element 37 will be moved towards the end surface of the lamp frame and the sleeve 32 will be moved into its covering position, in which it covers the electric contacts of the pin 31. This covering position of the sleeve 32 is shown in FIG. 3B. Advantageously, the motion of the sleeve 32 is limited in the distal direction, whereby the sleeve 32 is pre-tensioned so that it cannot be pushed away from the pin 31 unless a threshold force is applied.

(26) In the use position, the activating member 34 may be further arranged to connect the pin 31 and the lighting module (e.g. by the means of the switch), thereby enabling a current path from the lighting module to the electric contact.

(27) FIG. 3C shows the lamp 3 when the activating member 34 is in the use position, but when a force is exerted on the sleeve 32, which force has urged the sleeve 32 to be slid into the compartment 38 against the action of the spring 33. As a result, the sleeve 32 is positioned in its uncovering position, in which is uncovers the electric contact of the pin 32, as shown in FIG. 3C. The force urging the sleeve 32 into its uncovering position may e.g. be exerted by a surface of a lamp fitting (not shown) as the lamp 3 is installed.

(28) An example of how the lamp 3 according to the present embodiment can be used will now be described, still with reference to FIGS. 3A-3C.

(29) During transport and handling of the lamp 3, the activating member 34 may preferably be set in the transport position (as shown in FIG. 3A), wherein the pin 32 is disconnected to the lighting module, since the lighting module need not be powered in this phase. Advantageously, the activating member 34 may still be in the transport position during installation of the lamp 3 in the lamp fitting. Setting the activating member in the transport position ensures that the pin 32 is unable to become live when the lamp 3 is partially installed in the lamp fitting, as the current path from the lighting module to the pin 31 is interrupted.

(30) When the lamp 3 has been properly installed in the lamp fitting, the installer may actuate the activating member 34 into its use position, whereby the pin 31 is connected to the lighting module to enable powering of the lighting module. Since the lamp 3 is mounted in the lamp fitting, the sleeve 32 is urged into its uncovering position as shown in FIG. 3C.

(31) If the activating member 34 is difficult, or even impossible, to access when the lamp 3 is in its installed position in the lamp fitting, it is advantageous to set the activating member 34 in the use position prior to the installation. The sleeve 32 will then be moved to its covering position, which is shown in FIG. 3B, thereby protecting the installer from the potentially live electric contact of the pin 31 when the lamp 3 is partially installed. As the end of the lamp 3 is inserted in the lamp fitting, the sleeve 32 will be urged back to its uncovering position shown in FIG. 3C.

(32) Upon removal of the lamp 3 from the lamp fitting, the sleeve 32 will flip to its covering position if the activating member 34 is in the use position. Alternatively, the activating member 34 may be put in the transport position (by the installer) prior to the removal of the lamp 3.

(33) It will be appreciated that the activating member 34 may be adjusted between the transport position and the use position on any occasion, as desired. For example, the activating member 34 may be in the use position also during transport and handling of the lamp 3.

(34) The person skilled in the art realizes that the present invention by no means is limited to the preferred embodiments described above. On the contrary, many modifications and variations are possible within the scope of the appended claims. For example, features (such as shapes, materials and measures) of the lamp described with reference to FIGS. 2A and 2B may also be applied to the lamp described with reference to FIGS. 3A-3C, and vice versa.