Patent Publication Number: US-11396988-B2

Title: Vehicle LED lamp having a bulb base tensioning spring

Description:
TECHNICAL FIELD 
     The subject matter disclosed herein relates generally to headlight bulbs for a vehicle headlight. More particularly, the subject matter disclosed herein relates to LED headlight bulbs for use with vehicle lamp bases that require a minimum holding force. 
     BACKGROUND 
     Some standards for halogen vehicle lamp bases, such as H11, H8, H9 and H16, are specified to require a minimum holding force (e.g., a minimum of 5N of force) once the bulb is inserted into the fixture to ensure that the bulb is correctly seated to ensure alignment of the optics. Because the opening into which the bulb is inserted in the lamp housing must be slightly larger than the bulb itself to provide appropriate tolerances to allow the bulb to be inserted, such a holding force is typically achieved using a base tension spring that creates the minimum holding force when the bulb is seated. In some configurations, a spring that maintains such a holding force can also accordingly require a higher force during insertion (e.g., about 10N of force). 
     There have been attempts to adapt light-emitting-diode (LED) systems to replace such halogen bulbs, but the differences in the technologies have presented some challenges in successfully adapting LED bulbs to replace conventional halogen bulbs. For example, whereas halogen bulbs can be characterized as cylindrical filament light sources that emit light in a substantially 360 degree pattern, LED bulbs generally have a limited illumination range due to LED elements being surface-mounted devices. As a result, even with an efficient configuration that includes multiple LED elements facing in different directions, there can still be dark spots in the illumination pattern such that different angular positions of the LED elements relative to the fixture result in different lighting patterns. In addition, a vast majority of reflector housing designs have dimensions that are longer horizontally, and the outer segments of the reflector typically carry critical beam center intensity and cut-off defining roles. Taken together, the alignment of LED elements relative to the housing/reflector plays a critical role in adapting a LED bulb for a given housing/reflector design. 
     SUMMARY 
     In accordance with this disclosure, headlight bulb devices, systems, and methods for vehicle headlights are provided. In one aspect, a headlight bulb assembly for a vehicle headlight is provided. The headlight bulb assembly includes a bulb mounting collar configured to be engaged with a bulb base cavity in a housing of the vehicle headlight; a bulb body comprising one or more LED element, wherein the bulb body is configured to be coupled to the bulb mounting collar, wherein the bulb body is rotatable to a range of angular positions relative to the bulb mounting collar; and a biasing element configured to apply a force that acts to retain one or both of the bulb mounting collar or the bulb body in an engaged position with respect to the bulb base cavity. 
     In another aspect, a vehicle headlight is provided. The vehicle headlight comprises a housing comprising a bulb base cavity; a bulb mounting collar configured to be engaged with the bulb base cavity; a bulb body comprising one or more LED element, wherein the bulb body is configured to be coupled to the bulb mounting collar, wherein the bulb body is rotatable to a range of angular positions relative to the bulb mounting collar; and a biasing element configured to apply a force that acts to retain one or both of the bulb mounting collar or the bulb body in an engaged position with respect to the bulb base cavity. 
     In yet another aspect, a method for coupling a headlight bulb to a vehicle headlight is provided. The method includes steps of coupling a bulb body to a bulb mounting collar, the bulb body comprising one or more LED element; engaging the bulb mounting collar with a bulb base cavity in a housing of the vehicle headlight; and applying a biasing force between the bulb body and the bulb base cavity to hold the bulb body in a desired position relative to the bulb base cavity. 
     Although some of the aspects of the subject matter disclosed herein have been stated hereinabove, and which are achieved in whole or in part by the presently disclosed subject matter, other aspects will become evident as the description proceeds when taken in connection with the accompanying drawings as best described hereinbelow. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The features and advantages of the present subject matter will be more readily understood from the following detailed description which should be read in conjunction with the accompanying drawings that are given merely by way of explanatory and non-limiting example, and in which: 
         FIG. 1  is a side cutaway view of a headlight bulb assembly installed in a headlight housing according to an embodiment of the presently disclosed subject matter; 
         FIG. 2  is an exploded side perspective view of elements of a headlight bulb assembly according to an embodiment of the presently disclosed subject matter; 
         FIG. 3  is a perspective side view of elements of a headlight bulb assembly according to an embodiment of the presently disclosed subject matter; 
         FIGS. 4A through 4E  are side views of an engagement mechanism for elements of a headlight bulb assembly according to an embodiment of the presently disclosed subject matter; 
         FIGS. 5A and 5B  are side perspective views of a bulb mounting collar according to an embodiment of the presently disclosed subject matter; 
         FIGS. 6A, 6C, and 6E  are top views of method steps for coupling a bulb mounting collar to a headlight housing according to an embodiment of the presently disclosed subject matter; and 
         FIGS. 6B, 6D, and 6F  are perspective side views of the method steps shown in  FIGS. 4A, 4C, and 4E , respectively. 
     
    
    
     DETAILED DESCRIPTION 
     The present subject matter provides headlight bulb devices, systems, and methods for vehicle headlights. In one aspect, the present subject matter provides a headlight bulb for a vehicle headlight. In one exemplary configuration shown in  FIG. 1 , a headlight bulb assembly, generally designated  100 , includes a bulb mounting collar  110  and a bulb body  120 . Bulb mounting collar  110  is configured to be received in a bulb base cavity  151  in a housing  150  of the vehicle headlight, which can include a reflector arrangement configured to redirect the light from headlight bulb assembly  100  outwardly with a desired illumination pattern. In some embodiments, a mounting gasket  130  is provided to help seal a mating surface between bulb mounting collar  110  and bulb base cavity  151 . Bulb body  120  is configured to be coupled to bulb mounting collar  110  such that bulb mounting collar  110  secures bulb body  120  in place with respect to housing  150 . 
       FIG. 2  illustrates an exploded view of the components of one exemplary configuration for headlight bulb assembly  100 . In the illustrated configuration, bulb mounting collar  110  comprises a ring-shaped structure having a substantially circular opening therethrough and one or more mounting flange  118  (also shown in  FIG. 1 ) configured for engaging a bulb base cavity  151  in a housing  150  as will be discussed below. Bulb body  120  includes a base portion  122  (also shown in  FIG. 1 ), which may include one or more cooling system elements and/or control elements. For example, in some embodiments, base portion  122  can include one or more of cooling fins, cooling fans, printed circuit board controller elements, electrical connectors, or insulating elements. Bulb body  120  further includes an elongated shaft portion  124  that is connected to and extends from the base portion  122  substantially along a center axis C. The shaft portion  124  includes one or more LED element  125 , which in some embodiments is carried on a circuit board element  126  that is integrated into the shaft portion  124 . 
     As indicated above, bulb body  120  is configured to be coupled to bulb mounting collar  110 . In some embodiments, the substantially circular opening in the ring-shaped structure of bulb mounting collar  110  is configured to receive bulb body  120  therethrough. Referring again to the embodiment shown in  FIG. 2 , the substantially circular opening through bulb mounting collar  110  can define a substantially cylindrical inner mounting surface  111 , and a portion of shaft portion  124  of bulb body  120  can include an exterior mounting surface  127  that has a substantially cylindrical shape that is sized and configured to nest within and mate with inner mounting surface  111 . In particular, for example, in some embodiments, shaft portion  124  is sized and configured at exterior mounting surface  127  to substantially correspond to a size and configuration of inner mounting surface  111  of bulb mounting collar  110  such that the surfaces can engage together in a press-fit arrangement. In addition, in some embodiments, headlight bulb assembly  100  can also include a coupling gasket  128  configured to help seal the connection between bulb mounting collar  110  and bulb body  120 . 
     Alternatively or in addition, in some embodiments, headlight bulb assembly  100  includes one or more further engagement elements configured to enhance the alignment and/or engagement of bulb body  120  with bulb mounting collar  110 . In some embodiments, such engagement elements are configured to selectively retain bulb mounting collar  110  and bulb body  120  in a desired relative angular orientation with respect to one another and/or in a desired axial position with respect to one another (e.g., along central axis C). 
     Referring to an exemplary embodiment shown in  FIG. 3 , exterior mounting surface  127  of bulb body  120  can include a first engagement element in the form of one or more locking nub  129  that protrudes radially outward from exterior mounting surface  127 . As illustrated in  FIG. 3 , for example, in some embodiments, two locking nubs  129  can be provided on substantially opposing sides of exterior mounting surface  127 , although those having ordinary skill in the art will appreciate that more or fewer locking nubs can be provided to achieve a desired coupling configuration. Correspondingly, bulb mounting collar  110  can include a a second engagement element in the form of a plurality of alignment notches  119  indented radially inward into inner mounting surface  111 , with each of the plurality of alignment notches  119  being configured to receive one of the one or more locking nub  129 . In this configuration, bulb body  120  can be coupled with bulb mounting collar  110  such that each of the one or more locking nub  129  engages with one of the plurality of alignment notches  119  to align bulb body  120  to a corresponding one of a plurality of discrete angular engagement positions relative to bulb mounting collar  110 . 
     First, in some embodiments, initial engagement of bulb mounting collar  110  with bulb body  120  can include passing bulb mounting collar  110  over shaft portion  124  of bulb body  120  until exterior mounting surface  127  is substantially nested within inner mounting surface  111  at a preliminary engagement position. In some embodiments, bulb mounting collar  110  includes one or more engagement rail  117  that is provided as a recessed track that extends along inner mounting surface  111  and that is configured to receive and guide the one or more locking nub  129  to the preliminary engagement position. In such a configuration, the preliminary engagement position can include the one or more locking nub  129  being positioned at or near an end of the one or more engagement rail  117 , and coupling gasket  128  being positioned in contact with both of bulb mounting collar  110  and bulb body  120 . 
     Once bulb mounting collar  110  is in the preliminary engagement position, bulb mounting collar  110  can be further depressed towards base portion  122  of bulb body  120  such that the one or more locking nub  129  passes beyond the one or more engagement rail  117  in the axial direction. In some embodiments, this further depression involves compressing coupling gasket  128 . From this position, bulb body  120  is rotatable relative to bulb mounting collar  110  to a desired angular orientation. Referring to  FIG. 4A , for example, at a given angular position, each of the one or more locking nub  129  seats within a respective one of the plurality of alignment notches  119 . In some embodiments, coupling gasket  128  exerts a force between base portion  122  and bulb mounting collar  110  to press bulb mounting collar  110  against the one or more locking nub  129  and thus bias the elements towards an engaged position. 
     Further in this regard, changing angular orientations can involve depressing bulb mounting collar  110  towards base portion  122  as shown in  FIG. 4B  (e.g., while compressing coupling gasket  128 ) and rotating one of bulb mounting collar  110  or bulb body  120  relative to the another as shown in  FIG. 4C . Once a new desired angular orientation is substantially reached, such as is shown in  FIG. 4D , bulb mounting collar  110  can be moved back away from base portion  122  such that each of the one or more locking nub  129  seats within a new respective one of the plurality of alignment notches  119 , such as is shown in  FIG. 4E . Again, this reseating can be achieved through a restoring force of coupling gasket  128  tending to press bulb mounting collar  110  away from base portion  122  such that each of the one or more locking nub  129  is pressed into a new respective one of the plurality of alignment notches  119 . In this way, bulb mounting collar  110  and bulb body  120  can be selectively engaged with one another in any of a plurality of relative angular positions. 
     In any configuration, by providing the headlight bulb as an assembly including multiple separate components, the position of the one or more LED element  125  can be adjusted independently from the connection of bulb mounting collar  110  to housing  150 . Specifically, for example, in embodiments in which the opening in bulb mounting collar  110  is substantially circular, and exterior mounting surface  127  of bulb body  120  is substantially cylindrical, engagement between the elements can be achieved regardless of the angular position of bulb body  120  with respect to central axis C. Thus, in some embodiments, bulb body  120  can be rotatable to a range of angular positions relative to bulb mounting collar  110  and thus with respect to housing  150 . In this regard, bulb body  120  need not be aligned at any particular angle with respect to bulb mounting collar  110  to be received by bulb mounting collar  110 . Rather, bulb mounting collar  110  is configured to enable engagement with bulb body  120  in any of a range of relative angular orientations. In this way, the position of the one or more LED element  125  can be characterized as “clock-able” within housing  150  in that the relative orientation of the one or more LED element  125  with respect to housing  150  can be adjusted to optimize the illumination pattern within housing  150 . 
     For example, in the configuration illustrated in  FIG. 1 , the one or more LED element  125  comprises two elements that are arranged on opposing sides of shaft portion  124  of bulb body  120 . In this arrangement, depending on the configuration of the reflector positioned within the housing  150  and the angular orientation of the one or more LED element  125  with respect to such a reflector, there can be areas of poor illumination or no illumination in the lighting pattern produced by headlight bulb assembly  100 . By enabling bulb body  120  to be rotatable independently from its connection to housing  150 , however, the relative position of the one or more LED element  125  can be adjusted with respect to housing  150  to correspond with the particular reflector configuration of housing  150 . In this way, the appearance of such darker spots can be reduced or eliminated by adjusting the orientation of the one or more LED element  125 . For example, in some embodiments, there can be an optimum angular position of the one or more LED element  125  with respect to housing  150  at which the headlight bulb assembly  100  produces an illumination pattern having a maximum total brightness, a maximum light distribution across the reflector, or to otherwise produce a desired characteristic of the illumination pattern. 
     While providing this adjustability to the position of the one or more LED element  125 , headlight bulb assembly  100  according to the presently disclosed subject matter can also provide the holding force that is desired in some headlight bulb configurations. As discussed above, some standards for halogen vehicle lamp bases are specified to require a minimum holding force (e.g., a minimum of 5N of force) once the bulb is inserted into the fixture to ensure that the bulb is correctly seated and/or to ensure alignment of the optics. To achieve this holding force, headlight bulb assembly  100  includes a biasing element  113  that is configured to apply a biasing force that acts to retain one or both of bulb mounting collar  110  or bulb body  120  in a desired position with respect to bulb base cavity  151 , such as in a position that optimally orients the one or more LED element  125  with respect to the optics of housing  150 . In some embodiments, for example, biasing element  113  is a tension spring. 
     For example, in one exemplary embodiment illustrated in  FIGS. 5A and 5B , bulb mounting collar  110  can include a cavity  115  on inner mounting surface  111 , and an opening  116  from cavity  115  is formed through bulb mounting collar  110 . Biasing element  113  can be provided as a tension spring that is sized and configured to be received in cavity  115 , and biasing element  113  can include a projection  114  that is configured to protrude through opening  116 . In this arrangement, when bulb mounting collar  110  and bulb body  120  are coupled together, biasing element  113  is secured in cavity  115  between inner mounting surface  111  of bulb mounting collar  110  and exterior mounting surface  127  of bulb body  120 , and projection  114  protrudes outwardly through opening  116 . In this arrangement, projection  114  of biasing element  113  can engage bulb base cavity  151  to help produce the holding force to keep headlight bulb assembly  100  seated within housing  150 . Thus, bulb mounting collar  110  can be engaged with bulb base cavity  151  of housing  150  with a holding force that acts to retain headlight bulb assembly  100  in place with respect to housing  150 . In addition, the biasing force applied by biasing element  113  can further help to secure bulb body  120  in place with respect to bulb mounting collar  110 . 
     In one particular coupling configuration illustrated in  FIGS. 6A through 6F , for example, housing  150  can be configured such that bulb base cavity  151  has a nonuniform opening that defines an arrangement of cutouts and indentations. Bulb mounting collar  110  can be sized and configured to pass through bulb base cavity  151  when aligned in a particular orientation. For example, the positions of projection  114  of biasing element  113  and/or the one or more mounting flange  118  can be designed to effectively align with cutouts in bulb base cavity  151 . In the configuration illustrated in  FIGS. 6A and 6B , opening  116  in bulb mounting collar  110  through which projection  114  of biasing element  113  protrudes is arranged in alignment with one or the one or more mounting flange  118 , and these elements are sized to pass through a first cutout  152  that extends outwardly from bulb base cavity  151  in housing  150 . Bulb mounting collar  110  is configured such that the one or more mounting flange  118  passes completely through bulb base cavity  151 , but projection  114  of biasing element  113  remains effectively aligned within bulb base cavity  151 . 
     When arranged in this way, bulb mounting collar  110  can be rotated as shown in  FIGS. 6C and 6D  such that the one or more mounting flange  118  passes over an indentation  153  that extends back inward relative to first cutout  152 , but projection  114  engages and is flexed inward by indentation  153 . In some embodiments, the spring constant k of biasing element  113  can be selected such that an engagement pressure is applied between bulb base cavity  151  and headlight bulb assembly  100  with a desired minimum force, which in some embodiments is selected to be about 10N. As shown in  FIGS. 6E and 6F , bulb mounting collar  110  can be further rotated until projection  114  passes beyond indentation  153  and flexes back up into a second cutout  154  that likewise extends outwardly from bulb base cavity  151 . In some embodiments, second cutout  154  extends a shorter distance radially outward than first cutout  152 . In this arrangement, projection  114  effectively “clicks” into place in second cutout  154 , but the one of the one or more mounting flange  118  is larger and cannot pass back through bulb base cavity  151 . When seated in this position, in some embodiments, edges of bulb base cavity  151  are bounded on one side by the one or more mounting flange  118  and on an opposing side by a lower portion of bulb mounting collar  110  and/or mounting gasket  130 . In this way, an axial force persists in pressing bulb mounting collar  110  in a sealing arrangement against housing  150 . In accordance with the preferred minimum holding force discussed above, bulb mounting collar  110  and/or mounting gasket  130  can be configured such that this axial force has a magnitude of at least 5N. 
     The present subject matter can be embodied in other forms without departure from the spirit and essential characteristics thereof. The embodiments described therefore are to be considered in all respects as illustrative and not restrictive. Although the present subject matter has been described in terms of certain preferred embodiments, other embodiments that are apparent to those of ordinary skill in the art are also within the scope of the present subject matter.