End cap of a lighting tube

An end cap of a lighting tube includes a first assembly member and a second assembly member. The first assembly member includes a first shell, several recesses, and two first position-limiting elements. The first shell has a first central-securing element, and the first shell forms a first area and a second area. The two first position-limiting elements are disposed on the first area. The second assembly member includes a second shell, a first elastic element, a second elastic element, and two positioning elements. An end of the second shell is connected to a lighting tube and a second central-securing element of the second shell is secured with the first central-securing element. The first elastic element is disposed on the second shell. The second elastic element is disposed on the second shell. The two positioning elements are disposed on the second shell.

RELATED APPLICATIONS

This application claims priority to Taiwan Application Serial Number 101136921, filed Oct. 5, 2012, which is herein incorporated by reference.

BACKGROUND

1. Field of Invention

The present invention relates to an end cap. More particularly, the present invention relates to an end cap of a lighting tube.

2. Description of Related Art

Light-emitting diodes (LEDs) have many advantages such as high efficiency and long life. Therefore, traditional fluorescent tubes are gradually being replaced by LEDs.

LEDs produce heat and high temperature during the conversion of electricity into light. When the temperature rises, the lighting efficiency and life span of light-emitting diodes decrease. Thus, there is a need to provide a heat sink in an LED lighting tube. However, such a heat sink may limit the lighting angle of the LED lighting tube so that the LED lighting tube cannot emit light in all directions (i.e., 360 degrees) like the mercury lighting tube.

Thus, a rotatable LED lighting tube that allows for adjustments in the lighting direction has been developed and offered on the market. However, such a rotatable LED lighting tube includes several complex components to allow rotation of the LED lighting tube. Therefore, the rotatable LED lighting tube has several problems such as high cost and complex assembly.

When a manufacturer produces both rotatable lighting tubes and the fixed lighting tubes, the manufacturer has to design and make two kinds of conventional end caps to be respectively secured with the rotatable lighting tubes and the fixed lighting tubes. Thus, the manufacturer must invest much time and effort into producing the two kinds of the conventional end caps, as they cannot be interchangeably used by the rotatable lighting tubes and the fixed lighting tubes. One consequence of this is the increased storage associated with having to stock two different types of end caps.

Therefore, there is a need to develop an end cap that is capable of avoiding the foregoing disadvantages.

SUMMARY

In accordance with the present invention, an end cap of a lighting tube includes a first assembly member and a second assembly member. The first assembly member includes a first shell, several recesses, and two first position-limiting elements. The first shell has a first central-securing element, and an annular inner wall of the first shell forms a first area and a second area. The recesses are formed in the first area of the annular inner wall of the first shell, and an angle formed between two lines each formed from one of two opposite ends of the first area to an axis of the first shell is less than 180°. The two first position-limiting elements are disposed on the two ends of the first area. The second assembly member includes a second shell, a first elastic element, a second elastic element, and two positioning elements. One end of the second shell is connected to a lighting tube, and the other end of the second shell has a second central-securing element that is secured with the first central-securing element such that the first central-securing element is capable of rotating relative to the second central-securing element. The first elastic element is disposed on the second shell, and the first elastic element has a first protrusion that is received in one of the recesses. The second elastic element is disposed on the second shell, and the second elastic element has a second protrusion that is abutted against one of the recesses. The two positioning elements are disposed on the second shell, and the two positioning elements and the first elastic element are respectively disposed on the two opposite sides of the second central-securing element.

According to another embodiment disclosed herein, the angle formed between the two lines each formed from one of the two opposite ends of the first area to the axis of the first shell is 135°.

According to another embodiment disclosed herein, the first central-securing element has a first hook portion and the second central-securing element has a second hook portion, and the first hook portion is secured with the second hook portion such that the first central-securing element is rotatably secured with the second central-securing element.

According to another embodiment disclosed herein, the second elastic element is located between the two positioning elements.

According to another embodiment disclosed herein, a vertical height of each of the positioning elements is greater than a vertical height of the first elastic element and a vertical height of the second elastic element.

According to another embodiment disclosed herein, the vertical height of the first elastic element is equal to the vertical height of the second elastic element.

According to another embodiment disclosed herein, a gap is formed between the first elastic element and one of the two first position-limiting elements when the first assembly member is secured with the second assembly member and the first elastic element is aligned with the one of the two first position-limiting elements.

According to another embodiment disclosed herein, the first assembly member has two second position-limiting elements, and one of the two positioning elements is abutted against one of the two second position-limiting elements to restrict rotation of the first assembly member relative to the second assembly member about a direction when the first protrusion is received in one of the recesses located on the two opposite ends of the first area.

According to another embodiment disclosed herein, the first shell has an opening, and the maximum vertical distance between one of the recesses and the opening is less than the minimum vertical distance between one of the first position-limiting elements and the opening.

According to another embodiment disclosed herein, when the first assembly member is secured with the second assembly member and the two positioning elements are abutted against the second position-limiting elements, the first assembly member is locked in the second assembly member such that the first assembly member cannot rotate relative to the second assembly member.

According to another embodiment disclosed herein, a rotating angle of the first assembly member rotates relative to the second assembly member is less than or equal to 180° when the first assembly member is secured with the second assembly member and the two positioning elements are located in the second area.

According to another embodiment disclosed herein, the rotating angle of the first assembly member rotates relative to the second assembly member is more than 180° when the first assembly member is secured with the second assembly member and the two positioning elements are located in the second area.

The end cap may be applied to a rotatable end cap or a fixed end cap when the first assembly member is secured with the second assembly member in different ways. Therefore, the end cap can be applied to a rotatable lighting tube or a fixed lighting tube. In addition, the cost of producing the end cap and the assembly complexity of the end cap may be reduced because the first assembly member and the second assembly member have fewer components.

DETAILED DESCRIPTION

FIG. 1shows a side view of an end cap100secured with a lighting tube200according to an embodiment of the present invention. An end of a lighting tube200is inserted into the end cap100such that the lighting tube200is secured with the end cap100. After a connecting terminal210is extended through the end cap100and electrically connected to an external power source, the lighting tube200may operate to emit light using the electric power from the external power source. In this embodiment, a first assembly member100ais secured with a second assembly member100bto form the end cap100. Because the lighting tube200is a cylindrical lighting tube, a configuration of the second assembly member100bneeds to be cylindrical such that the second assembly member100bmay be secured with the lighting tube200. In addition, a configuration of the first assembly member100aalso needs to be cylindrical such that the first assembly member100amay be secured with the second assembly member100b.

FIG. 2shows a perspective view of the first assembly member100aof the end cap100ofFIG. 1. The first assembly member100ahas a first shell110and several recesses120formed in an annular inner wall114of the first shell110, in which the recesses120may be equally spaced apart along the annular inner wall114of the first shell110. In addition, the first shell110has a first surface110aand a second surface110b, and two first position-limiting elements130are disposed on a surface of the annular inner wall114of the first shell110, in which each of the first position-limiting elements130is disposed on the annular inner wall114near the second surface110bof the first shell110.

The first shell110has a first central-securing element112formed around an axis116of the first shell110. That is, the central-securing element112is vertically extended outward from the second surface110bof the first shell110about the axis116of the first shell110. In addition, a first area114aand a second area114bare formed on the annular inner wall114of the first shell110. The recesses120are formed in the first area114aof the annular inner wall114, in which each of the recesses120is recessed inward in the first area114aof the annular inner wall114and extended in a direction from the first surface110atoward the second surface110b. The recesses120may appear as several semi-circular gaps located on the first surface110awhen viewed from above, and each of the recesses120is formed in a semi-cylindrical hollow configuration when seen from an angle allowing full view of the length thereof. In addition, a space114a′ is formed between each of the recesses120and the second surface110b. In this embodiment, an angle θ1of less than 180° is formed between lines that each interconnects one of the ends of the first area114aand the axis116of the first shell110. In other embodiments, the angle θ1that is formed between the lines that each interconnects one of the ends of the first area114aand the axis116of the first shell110is 135°.

The first position-limiting elements130are disposed at the two ends of the first area114aof the annular inner wall114near the second surface110b, in which a height of each of the first position-limiting elements130is less than the space114a′ between each of the recesses120and the second surface110b. In other words, intervals101aare formed between the first position-limiting elements130and the recesses120that are aligned with the first position-limiting element130.

In this embodiment, the recesses120are disposed in the first area114a, as well as in a portion of the second area114bthat is opposite to the first area114a. In another embodiment, the recesses120may be disposed along the entire the annular inner wall114of the first shell110. In this embodiment, the first position-limiting elements130are disposed in the first area114, but the present invention is not limited in this regard.

FIG. 3shows a perspective view of the second assembly member100bof the end cap100ofFIG. 1. The second assembly member100bis secured with the first assembly member100ato form the end cap100, as described above. The second assembly member100bincludes a second shell150, several first elastic elements160, a second elastic element170, and two positioning elements180. In this embodiment, the number of the first elastic elements160is three. In another embodiment, the number of the first elastic element160may be at least one.

An end150aof the second shell150is used for being connected to the lighting tube200(seeFIG. 1). A second central-securing element152is formed about an axis of an opposite end150bof the second shell150. The first central-securing element112is rotatably secured with the second central-securing element152(seeFIG. 2).

The first elastic elements160are disposed on the second shell150and located on the same end150bof the second shell150on which the second central-securing element152is located. The first elastic elements160are disposed outwardly from the second central-securing element152. In this embodiment, each of the first elastic elements160is a rectangular plate. In another embodiment, each of the first elastic elements160may be a plate having another shape. Each of the first elastic elements160has a first protrusion162. Each of the first protrusions162is a bump-like structure formed on an outer wall of the corresponding first elastic element160. When the first assembly member100ais secured with the second assembly member100b, each of the first protrusions162may be received in one of the recesses120(seeFIG. 2). In this embodiment, the first protrusions162are circular bump-like structures disposed on the outer wall of the first elastic elements160such that each of the first protrusions162may be smoothly slipped into and out of one of the recesses120. In this embodiment, each of the first protrusions162is located on an outer surface of an end of one of the first elastic elements160at a distance from the second shell150, and on a central axis160aof the one of the first elastic elements160.

In this embodiment, the second elastic element170is disposed on the second shell150and located on the same end150bof the second shell150on which the second central-securing element152is disposed. The second elastic element170is disposed outwardly from the second central-securing element152. In this embodiment, the second elastic element170is a rectangular plate. In another embodiment, the second elastic elements170may be a plate having another shape. The second elastic element170has a second protrusion172. The second protrusion172is a bump-like structure formed on an outer wall of the second elastic element170. When the first assembly member100ais secured with the second assembly member100b, the second protrusion172may be received in one of the recesses120to strengthen the assembly stability after the first assembly member100ais secured with the second assembly member100b(seeFIG. 1andFIG. 2). In this embodiment, the second protrusion172is a circular bump-like structure disposed on the outer wall of the second elastic element170such that the second protrusion172may be smoothly slipped into and out of one of the recesses120. In this embodiment, the second protrusion172is located on an outer surface of an end of the second elastic element170at a distance from the second shell150, and on a central axis170aof the second elastic element170. In this embodiment, the center first elastic element160(i.e., the first elastic element160at the center of the other two first elastic elements160) and the second elastic element170are disposed on two opposite sides of the second central-securing element152.

The two positioning elements180are disposed on the second shell150and also located on the same end150bof the second shell150on which the second central-securing element152is located. The two positioning elements180are disposed outwardly from the second central-securing element152and in a manner such that the second elastic element170is located between the two positioning elements180. The two positioning elements180and the first elastic elements160are respectively disposed on two opposite sides of the second central-securing element152. In addition, a vertical height of each of the positioning elements180is greater than a vertical height of the first elastic elements160and a vertical height of the second elastic element170. In this embodiment, each of the two positioning elements180is a rectangular plate. In another embodiment, each of the two positioning elements180may be a plate having another shape as long as the vertical height of each of the positioning elements180is greater than the vertical height of the first elastic elements160and the vertical height of the second elastic element170.

In this embodiment, the number of the first elastic elements160is three and the number of the second elastic element170is one, but the present invention is not limited in this regard. Moreover, in this embodiment, the vertical height of the first elastic elements160and the vertical height of the second elastic element170are the same. In another embodiment, the vertical height of the first elastic elements160may be different from the vertical height of the second elastic element170.

FIG. 4shows a cross-sectional view of the end cap100assembled using a first assembly configuration taken along line A-A′ ofFIG. 1, andFIG. 5shows a cross-sectional view of the end cap100assembled using the first assembly configuration taken along line B-B′ ofFIG. 1. The first assembly member100ais secured with the second assembly member100bto form the end cap100when the first central-securing element112is secured with the second central-securing element152and the two positioning elements180are both located in the first area114a. The vertical height of each of the positioning elements180is greater than the vertical height of the first elastic elements160and the vertical height of the second elastic element170, and moreover, the vertical height of each of the positioning elements180is greater than a vertical height of the recesses120that are secured with the first elastic elements160or the second elastic element170. When the first assembly member100ais secured with the second assembly member100band the two positioning elements180are abutted against the second position-limiting elements130, the first assembly member100ais locked in the second assembly member100bsuch that the first assembly member100acannot rotate relative to the second assembly member100b. In other words, when the first assembly member100ais secured with the second assembly member100band the two positioning elements180are abutted against the two second position-limiting elements130, the first assembly member100ais locked in the second assembly member100bsuch that the first assembly member100acannot rotate relative to the second assembly member100bto form a fixed end cap.

In addition, when the first assembly member100ais secured with the second assembly member100b, the first elastic elements160are disposed adjacent to an equal number of the recesses120and the first protrusions162of the first elastic elements160are received in these recesses120for strengthening the assembly stability between the first assembly member100aand the second assembly member100b. Moreover, the second elastic element170is disposed adjacent to one of the recesses120and the second protrusion172of the second elastic element170is received in the one of the recesses120for strengthening the assembly stability between the first assembly member100aand the second assembly member100b. Therefore, when the first assembly member100ais secured with the second assembly member100band the two positioning elements180are located in the first area114a, the first assembly member100ais secured with the second assembly member100bto form the end cap100having a strong securing stability, and in addition, the end cap100is not rotatable because the first protrusions162of the first elastic elements160and the second protrusion172of the second elastic element170are received in the recesses120.

FIG. 6shows a cross-sectional view of the end cap100assembled using a second assembly configuration taken along line A-A′ ofFIG. 1. When the first assembly member100ais secured with the second assembly member100band the two positioning elements180(seeFIG. 4) are not both located in the first area114a, a first hook portion112aof the first central-securing element112is secured with a second hook portion152aof the second central-securing element152such that the first central-securing element112is rotatably secured with the second central-securing element152. Therefore, when the two positioning elements180(seeFIG. 4) are not simultaneously locked by the position-limiting elements130, the first assembly member100ais rotatably secured with the second assembly member100b.

When the first assembly member100ais secured with the second assembly member100band any one of the first elastic elements160is aligned with one of the two first position-limiting elements130, a gap101ais formed between the any of the first elastic elements160and the one of the two first position-limiting elements130. In other words, when the first assembly member100arotates relative to the second assembly member100b, there is no interference between the first elastic elements160and the first position-limiting elements130.

FIG. 7shows a cross-sectional view of the end cap assembled using the second assembly configuration taken along line B-B′ ofFIG. 1. The first assembly member100ahas two second position-limiting elements140. The two second position-limiting elements140are disposed on two opposite sides of the annular inner wall114of the first shell110. In this embodiment, an angle θ2formed between lines interconnecting the two second position-limiting elements140with the axis116is substantially less than or equal to 180°.

When one of the first protrusions162is aligned with one of the recesses120that are located in the two opposite ends of the first area114a, one of the two positioning elements180is abutted against one of the two second position-limiting elements140to restrict further rotation of the first assembly member100arelative to the second assembly member100bin a direction. In other words, when one of the two positioning elements180abuts against a lateral wall140aof one of the second position-limiting elements140, the two positioning elements180cannot be moved further toward the one of the second position-limiting elements140, and the first elastic elements160cannot rotate toward the opposite one of the second position-limiting elements140. Therefore, when the first assembly member100ais rotated relative to the second assembly member100bin this manner, a lighting angle of the lighting tube200(seeFIG. 1) may be adjusted.

When the first elastic elements160are positioned adjacent to an equal number of the recesses120, the first protrusions162of the first elastic elements160are received in these recesses120for strengthening the assembly stability between the first assembly member100aand the second assembly member100b. Moreover, the second elastic element170is disposed adjacent to one of the recesses120and the second protrusion172of the second elastic element170is received in the one of the recesses120for further strengthening the assembly stability between the first assembly member100aand the second assembly member100b. Therefore, after the first assembly member100ais rotated at an angle relative to the second assembly member100b, the first elastic elements160and the second elastic element170are secured with a number of the recesses120such that the first assembly member100ais steadily secured with the second assembly member100bto form the end cap100that is rotatable.

FIG. 8shows a schematic view of a rotating angle range of the two positioning elements180of the end cap100located within the second area114baccording to an embodiment of the present invention. In this embodiment, the end cap100does not have any second position-limiting elements140(seeFIG. 7) and the recesses120are equally spaced apart along the inner wall of the end cap100in the second area114b. Therefore, the rotating angle of the first assembly member100aand the second assembly member100bis more than 180° when the first assembly member100ais secured with the second assembly member100band the two positioning elements180are located in the second area114b.

According to above-described embodiments, the end cap may be assembled as a rotatable end cap or a fixed end cap when the first assembly member is secured with the second assembly member in different assembly configurations. Therefore, the end cap can be used as a rotatable lighting tube or a fixed lighting tube. In addition, the production cost and the assembly complexity of the end cap is low because the first assembly member and the second assembly member have few components.