Patent Publication Number: US-8974092-B2

Title: Lamp with air channel

Description:
This is a divisional application of U.S. patent application Ser. No. 12/770,893 filed on Apr. 30, 2010. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention generally relates to a lamp and, more particularly, to a lamp that is inserted into a ceiling for indoor or outdoor illumination. 
     2. Description of the Related Art 
     Taiwan Patent Publication No. M359644 discloses a lamp cooling apparatus comprising a base plate, an annular cooling seat, a fan and a housing. The base plate has a first face and a second face. The first face is mounted with a plurality of light-radiating elements and the second face is coupled with the annular cooling seat, with a plurality of vents extending from the first face to the second face. The fan is disposed on the annular cooling seat. The housing is coupled to the second face of the base plate in order for the annular cooling seat and the fan to be covered in the housing, wherein the first face that is mounted with the light-radiating elements faces outward. The housing has a plurality of stripped vents which allows external air to be drawn into the housing therethrough during rotation of the fan. The drawn-in air flows through the annular cooling seat for air exchange with the heat air generated by the light-radiating elements, and is then drawn out of the lamp via the vents of the base plate. 
     An embedded lamp refers to as a lamp that is inserted into a “plate ceiling” (means the ceiling that is assembled by a plurality of square plates) by inserting its housing into the ceiling so that the first face of the base plate mounted with the light-radiating elements faces downward for light radiation. In the situation, since the housing has been inserted into the plate ceiling, vents of the housing are located above the plate ceiling. However, the area above the plate ceiling is an enclosed space with poor air circulation, poor heat dissipation is therefore resulted. Furthermore, objects such as pipelines, cable lines or heat shield articles may be disposed in the enclosed area. Therefore, air circulation is further impacted. 
     As stated above, the conventional lamp has poor heat dissipation due to the structure design thereof, leading to a difficulty in dispelling the heat remained on the annular cooling seat. As a result, the service life of the lamp is reduced as the light-radiating elements have been long operated under a high temperature condition. Furthermore, the luminance of the light-radiating elements is also attenuated when the light-radiating elements are over-temperature. 
     Therefore, it is desired to improve the conventional lamp. 
     SUMMARY OF THE INVENTION 
     It is therefore the primary objective of the invention to provide a lamp with better cooling effect. 
     It is another objective of the invention to provide a lamp with longer service life. 
     It is still another objective of the invention to provide a lamp with a consistent level of luminance. 
     The invention discloses a lamp comprising a housing, an inner shell, a fan, a heat sink and a lighting module. The housing has a first compartment and a first opening on an end thereof. The inner shell is adapted to be received in the first compartment and has a second compartment and a second opening on an end thereof, wherein the second opening is aligned with the first opening. An air channel is formed between the housing and the inner shell in the first compartment. The inner shell further comprises a through-hole allowing the first compartment to communicate with the second compartment. The fan is located adjacent to the through-hole and has two air-flowing sides for drawing air in and out of the lamp such that the air is allowed to pass through the through-hole. The heat sink has a bottom plate with one face facing the fan. The lighting module is adapted to be coupled to another face of the bottom plate. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention will become more fully understood from the detailed description given hereinafter and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein: 
         FIG. 1  shows an exploded diagram of a lamp according to a first embodiment of the invention. 
         FIG. 2  shows a side cross sectional view of the lamp according to the first embodiment of the invention. 
         FIG. 3  shows a side cross sectional view of a lamp according to a second embodiment of the invention. 
         FIG. 4  shows an exploded diagram of a lamp according to a third embodiment of the invention. 
         FIG. 5  shows a side cross sectional view of the lamp according to the third embodiment of the invention. 
         FIG. 6  shows a side cross sectional view of a lamp according to a fourth embodiment of the invention. 
         FIG. 7  shows an exploded diagram of a lamp according to a fifth embodiment of the invention. 
         FIG. 8  shows a side cross sectional view of the lamp according to the fifth embodiment of the invention. 
     
    
    
     In the various figures of the drawings, the same numerals designate the same or similar parts. Furthermore, when the term “first”, “second”, “third”, “fourth”, “inner”, “outer” “top”, “bottom” and similar terms are used hereinafter, it should be understood that these terms are reference only to the structure shown in the drawings as it would appear to a person viewing the drawings and are utilized only to facilitate describing the invention. 
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to  FIGS. 1 and 2 , a lamp is disclosed according to a first embodiment of the invention. The lamp comprises a housing  1 , an inner shell  2 , a fan  3 , a heat sink  4  and a lighting module  5 . The inner shell  2  is to be received in the housing  1 . An air channel A is formed between the housing  1  and the inner shell  2  when the inner shell  2  is received in the housing  1 . The fan  3  is located adjacent to a through-hole  24  of the inner shell  2 . The heat sink  4  and lighting module  5  are located inside the inner shell  2 . During rotation of the fan  3 , air can flow in and out of the inner shell  2  through the through-hole  24  in order to have an air exchange with the heat air generated by the lighting module  5 . Thus, cooling of the lighting module  5  is achieved. 
     The housing  1  comprises a first compartment  11  and a first opening  12  on an end thereof. The housing  1  further comprises a first protrusion  13  which extends outward from a periphery of the first opening  12 . 
     The inner shell  2  has a second compartment  21  and a second opening  22  on an end thereof. The inner shell  2  further comprises a second protrusion  23  which extends outward from a periphery of the second opening  22 . A diameter D 1  of the inner shell  2  is preferably smaller than a diameter D 2  of the first compartment  11 . The second opening  22  preferably has the same shape as the first opening  12 . In addition, the second opening  22  preferably has a diameter smaller than that of the first opening  12  such that the second opening  22  is covered in the range of the first opening  12  when the inner shell  2  is received in the first compartment  11 . The through-hole  24  extends from an outer surface of the inner shell  2  to an inner surface of the inner shell  2  so that the first compartment  11  is allowed to communicate with the second compartment  21 . 
     A separation member  14  is disposed between the housing  1  and the inner shell  2 , which may be in a stick-like, column-like, block-like or strip-like form, such as ribs, pillars or blocks and so on. The separation member  14  may be disposed on an inner surface of the housing  1  or an outer surface of the inner shell  2  so as to space the housing  1  from the inner shell  2 . In the embodiment, the separation member  14  is in form of a plurality of ribs disposed on the inner surface of the housing  1  and is in surface contact with the outer surface of the inner shell  2 . 
     The fan  3  may guide the air through the through-hole  24  and has two air-flowing sides, namely, an air inlet  31  and an air outlet  32 . 
     The heat sink  4  is preferably made of a material with high heat conductivity. The heat sink  4  comprises a bottom plate  41  having one face mounted with a plurality of fins  42 . 
     The lighting module  5  comprises a base plate  51  and a plurality of lighting elements  52 . The lighting elements  52  may preferably be light-emitting diodes (LEDs) mounted on one face of the base plate  51 . 
     Referring to  FIGS. 1 and 2  again, during assembly of the lamp, the second opening  22  is aligned with the first opening  12  and covered in the range of the first opening  12  when the inner shell  2  is received in the first compartment  11 . The housing  1  is spaced from the inner shell  2  by the ribs so that the air channel A between the housing  1  and the inner shell  2  is formed. In addition, a ventilation opening B may be formed between the first protrusion  13  and the second protrusion  23  via the separation members  14  separating the housing  1  from the inner shell  2 , thereby allowing the external air to flow into the air channel A via the ventilation opening B. 
     The fan  3  may be disposed adjacent to or in the through-hole  24 , with one air-flowing side thereof communicating with the air channel A and another air-flowing side thereof communicating with the second compartment  21  to allow air flow between the air channel A and the second compartment  21 . In the embodiment, the fan  3  is disposed in a location adjacent to the through-hole  24  in the second compartment  21 , with the air inlet  31  communicating with the air channel A and the air outlet  32  communicating with the second compartment  21 . In this way, external air is drawn into the lamp via the ventilation opening B and flows into the second compartment  21  via the air channel A and the through-hole  24 . 
     The heat sink  4  is disposed in the second compartment  21 , with the face of the bottom plate  41  mounted with the fins  42  preferably facing the air outlet  32 . The fins  42  may be evenly spaced on the bottom plate  41 . Alternatively, as shown in the embodiment, the fins  42  may be disposed along a periphery of the bottom plate  41  so as to form a circular space for receiving the fan  3 . 
     The base plate  51  of the lighting module  5  is coupled to another face of the bottom plate  41  not mounted with the fins  42 , with the lighting elements  52  facing the second opening  22 . A covering plate  25  may be further disposed on the second opening  22 . The covering plate  25  is preferably a light-permeable plate that allows passage of lights, such as a transparent or translucent plate. The covering plate  25  has a plurality of vents  251  preferably located along a periphery thereof. 
     Referring to  FIG. 2 , when in use, the housing  1  is inserted into a ceiling  9 , with the first protrusion  13  of the housing  1  abutting upward with the ceiling  9 . When the fan  3  rotates, the air can flow between the air channel A and the second compartment  21  via the through-hole  24 , enabling the air to flow through the heat sink  4  for dispelling the heat air generated by the lighting module  5 . The direction of air flow may be changed by switching the rotation directions of the fan  3 . For example, when the fan  3  rotates in a clockwise direction, the external air is drawn into the second compartment  21  via the ventilation opening B, air channel A and through-hole  24 , and then drawn out of the lamp via, the vents  251 . On the contrary, when the fan  3  rotates in a countclockwise direction, the external al air is drawn into the second compartment  21  via the vents  251 , and then drawn out of the lamp via through-hole  24 , air channel A and ventilation opening B. Thus, the heat generated by the lighting module  5  is dispelled. 
     Despite the rotation direction of the fan  3 , since the ventilation opening B and the vents  251  are both located beneath the ceiling  9  rather than above the ceiling  9 , the ventilation opening B and the vents  251  are allowed to communicate with the external air. Thus, the air inside the lamp is allowed to have a smooth circulation with the external air. Besides, since the ventilation opening B is separated from the vents  251  by the second protrusion  23 , it is avoided that the exhausted heat air be immediately drawn into the lamp again. Thus, better ventilation and cooling effects of the lamp are provided. 
     Referring to  FIG. 3 , a lamp is disclosed according to a second embodiment of the invention. The lamp comprises a housing  1 , an inner shell  2 , a fan  3 , a heat sink  4  and a lighting module  5 . A covering plate  25 ′ is also disposed on the second opening  22  of the inner shell  2 . 
     In contrast to the previous first embodiment, a separation portion  252 ′ is disposed on one face of the covering plate  25 ′ facing the lighting module  5 . The separation portion  252 ′ is preferably in form of an annular lateral wall, with a plurality of vents  251 ′ being located out of an encompassed range of the separation portion  252 ′. In addition, when the covering plate  25 ′ is assembled in the second opening  22  of the inner shell  2 , a top side of the separation portion  252 ′ is in contact with the bottom plate  41  of the heat sink  4 , allowing the lighting module  5  to be located inside the encompassed range of the separation portion  252 ′. 
     Based on this, when the fan  3  rotates in a direction, external air is drawn into the lamp via the ventilation opening B and the air channel A, then flows through the through-hole  24  and the heat sink  4  and is finally drawn out of the lamp via the vents  251 ′ of the covering plate  25 ′. On the contrary, when the fan  3  rotates in another direction, external air is drawn into the lamp via the vents  251 ′ of the covering plate  25 ′, then flows through the heat sink  4  and the through-hole  24  and is finally drawn out of the lamp via the ventilation opening B. 
     Despite the rotation directions of the fan  3 , the lighting elements  52  or circuit chip of the lighting module  5  is separated from the external air by the separation portion  252 ′, thus avoiding accumulation of dust inside the lamp. 
     Referring to  FIG. 4 , a lamp is disclosed according to a third embodiment of the invention. The lamp comprises a housing  1 ′, an inner shell  6 , a fan  3 ′, a heat sink  4 ′ and a lighting module  5 ′. 
     In contrast to the previous embodiment, the inner shell  6  has a second compartment  61  and a plurality of vents  64 . The fan  3 ′ is preferably located adjacent to and surrounded by the vents  64  such that the air can flow between the air channel A and the second compartment  61  via the vents  64 . The inner shell  6  further comprises an air-guiding cap  65  in form of a plate. The air-guiding cap  65  has an assembly hole  651 , an annular portion  652  and an extension portion  653 . The assembly hole  651  is located on a center of the air-guiding cap  65  for receiving the fan  3 ′. The annular portion  652  extends outward and downward in a curved manner from an outer periphery thereof to form the extension portion  653 , so as to facilitate the air flows of the lamp. An outer periphery of the extension portion  653  is coupled to the inner shell  6  during assembly. The vents  64  are covered under the air-guiding cap  65  when the air-guiding cap  65  is coupled to the inner shell  6 . 
     A plurality of supporting columns  66  is disposed between the housing  1 ′ and the inner shell  6 . Specifically, the supporting columns  66  are disposed on a second protrusion  63  of the inner shell  6  and abut upward with a first protrusion  13 ′ of the housing  1 ′. Thus, the housing  1 ′ is spaced from the inner shell  6  by the supporting columns  66 . 
     Referring to  FIGS. 4 and 5 , during assembly of the lamp, the second opening  22  is aligned with a first opening  12 ′ of the housing  1 ′ and covered in the range of the first opening  12 ′ when the inner shell  6  is received in a first compartment  11 ′. An air channel A is formed by the supporting columns  66  spacing the housing  1 ′ from the inner shell  6 . A ventilation opening B is formed between the second protrusion  63  and the first protrusion  13 ′. 
     Referring to  FIG. 5 , the fan  3 ′ is disposed in the air-guiding cap  65  and the heat sink  4 ′ is disposed on the inner shell  6 . The heat sink  4 ′ comprises a bottom plate  41 ′ having one face mounted with a plurality of fins  42 ′, with the face mounted with the fins  42 ′ preferably facing the fan  3 ′. The base plate  51  of the lighting module  5  is coupled to another face of the bottom plate  41 ′ not mounted with the fins  42 ′, with the lighting elements  52  facing a second opening  62  of the inner shell  6 . 
     Referring to  FIG. 5 , when in use, the housing  1 ′ is inserted into the ceiling  9 , with the first protrusion  13 ′ of the housing  1 ′ abutting upward with the ceiling  9 . When the fan  3 ′ rotates, the air can flow between the air channel A and the second compartment  61  via the vents  64 , enabling the air to flow through the heat sink  4 ′ for dispelling the heat air generated by the lighting module  5 . Therefore, the third embodiment facilitates not only the ventilation but also the cooling of the lamp. 
     Referring to  FIG. 6 , a lamp is disclosed according to a fourth embodiment of the invention. The lamp comprises a housing  1 ″, an inner shell  2 ′, a fan  3 ′, a heat sink  4 ′ and a lighting module  5 . In contrast to the previous three embodiments, the inner shell  2 ′ has a second compartment  21 ′ extending outward to form a second protrusion  22 ′. An outer periphery of the second protrusion  22 ′ is coupled to a circumference of a first opening  11 ″ of the housing  1 ″ so as to close the first opening  11 ″. An air channel A is also formed between the housing  1 ″ and the inner shell  2 ′. The housing  1 ″ has a plurality of vents  12 ″ which is adjacent to the first opening  11 ″ and located on an outer surface thereof. 
     When in use, the housing  1 ″ is inserted into the ceiling  9  in a way that the vents  12 ″ are allowed to communicate with the outside air beneath the ceiling  9 . When the fan  3 ′ rotates, the air can be drawn into the lamp via the vents  12 ″ and the air channel A, enabling the air to flow through the heat sink  4 ′ for dispelling the heat air generated by the lighting module  5  and then to be drawn out of the lamp via vents  23 ′. In the embodiment, because the first opening  11 ″ is closed by the second protrusion  22 ′, the lamp has a better visual effect. 
     Referring to  FIGS. 7 and 8 , a lamp is disclosed according to a fifth embodiment of the invention. The lamp comprises a housing  7 , an inner shell  8 , a fan  3 , a heat sink  4  and a lighting module  5 . In contrast to the first embodiment, the housing  7  comprises a first protrusion  73  abutting with a second protrusion  83  of the inner shell  8  such that a first opening  72  of the housing  7  is closed by the second protrusion  83 . 
     The housing  7  has a separation member  74  in form of a labyrinth protrusion which is located in a first compartment  71  thereof and abuts with an inner surface thereof. The inner shell  8  has a separation member  85  also in form of a labyrinth protrusion abutting with an outer surface thereof. The housing  7  is spaced from the inner shell  8  via the separation members  74  and  85 , thus forming an air channel A. 
     In the embodiment, the separation embers  74  and  85  abut with each other so that the air channel A is separated into a first air channel A 1  and a second air channel A 2 . The inner shell  8  has a through-hole  84  in communication with the first air channel A 1 . The first air channel A 1  communicates with a second compartment  81  of the inner shell  8  via the through-hole  84 . The inner shell  8  has a plurality of stripped vents  86  in communication with the second air channel A 2  such that the second air channel A 2  is allowed to communicate with the second compartment  81  via the stripped vents  86 . The second protrusion  83  of the inner shell  8  has a plurality of first vents  87   a  and a plurality of second vents  87   b , with the first vents  87   a  communicating with the first air channel A 1  and the second vents  87   b  communicating with the second air channel A 2 . 
     When the fan  3  rotates in a direction, the external air can be drawn into the lamp via the first vents  87   a , then flows through the first air channel A 1 , through-hole  84 , second compartment  81 , stripped vents  86  and second air channel A 2 , and is finally drawn out of the lamp via second vents  87   b . Alternatively, when the fan  3  rotates in another direction, the external air can be drawn into the lamp via the second vents  87   b , then flows through the second air channel A 2 , stripped vents  86 , second compartment  81 , through-hole  84  and first air channel A 1 , and is finally drawn out of the lamp via first vents  87   a . Thus, heat generated by the lighting module  5  is dispelled. 
     The first vents  87   a  and second vents  87   b  may be selectively located on an outer surface of the housing  7  adjacent to the first opening  72 , with the first vents  87   a  communicating with the first air channel A 1  and the second vents  87   b  communicating with the second air channel A 2 . In this way, the external air can flow in and out of the lamp through the same paths described above. 
     A separation plate  88  may be further disposed in the second compartment  81  of the inner shell  8  so as to separate the second compartment  81  into an upper compartment  81   a  and a lower compartment  81   b , with the through-hole  84  and the stripped vents  86  communicating with the upper compartment  81   a . The separation plate  88  has an assembly hole  881 , with the lighting elements  52  of the lighting module  5  preferably disposed in the assembly hole  881  and facing the lower compartment  81   b . A covering plate  89  may be disposed in the second opening  82  of the inner shell  8 , with the covering plate  89  being preferably made of a light-permeable material such as a transparent or translucent plate. With the covering plate  89 , the lighting elements  52  or circuit chip of the lighting module  5  is separated from external air, avoiding accumulation of dust inside the lamp. 
     As stated above, the air channel and the vents of the lamp are allowed to communicate with the outside air beneath the ceiling when the housing of the lamp is inserted into the ceiling, thus allowing the external air to enter the lamp for air circulation. In this way, heat dissipation of the lamp is increased. 
     The invention facilitates heat dissipation of a lighting module of a lamp by providing the lamp with better air circulation and cooling effect, thereby prolonging the service life of the lamp. 
     The invention facilitates heat dissipation of a lighting module of a lamp so that the luminance attenuation of the lighting module resulted from a high temperature operation is avoided. 
     Although the invention has been described in detail with reference to its presently preferable embodiment, it will be understood by one of ordinary skill in the art that various modifications can be made without departing from the spirit and the scope of the invention, as set forth in the appended claims.