Abstract:
A lamp adjuster for adjusting the aim of a headlamp. The adjuster includes a housing having a first adjustment point, a gear having a second adjustment point, and an output shaft disposed at least partially within and functionally engaging the gear. Movement of the output shaft can be effected using either the first adjustment point or the second adjustment point. The adjuster can also include a clutching feature.

Description:
BACKGROUND OF THE INVENTION 
   The present invention relates generally to adjusters that are used to adjust the aim of a vehicle lamp. Specifically, this invention relates to a vehicle lamp adjuster that can be adjusted from more than one location and can include a clutching mechanism. 
   Vehicles such as automobiles typically have several lamps including head lamps and fog lamps. These lamps generally include a housing supporting a reflector and a lens with a bulb mounted therebetween, and are often securely fit into mounting brackets attached to the vehicle. Together, a lamp and a mounting bracket form a complete lamp assembly. Once the lamp assembly has been manufactured and installed into a vehicle, the lamp must be adjusted to the proper aim. As a result of accidents, maintenance, and normal vibrations and wear, the aim of the lamp must be occasionally adjusted during the lifetime of the vehicle as well. 
   One method of adjusting the aim of the lamp involves using an adjuster. The adjuster may be formed as part of the mounting bracket or may be a separate part that communicates with both the lamp and the mounting bracket. One known type of adjuster comprises a housing and an output shaft extending therefrom. The output shaft is engaged to the lamp. Actuation or operation of the adjuster causes the output shaft to move with respect to the lamp assembly. Such movement causes the lamp to pivot or otherwise move with respect to the mounting bracket, thereby adjusting the aim of the lamp. 
   One example of this type of adjuster, disclosed in U.S. Pat. No. 6,257,747 to Burton, requires manual operation. The housing of the adjuster has an opening and a gear positioned inside the housing. The gear is functionally engaged to the output shaft. An input shaft is inserted into the opening and interacts with the gear. Actuation of the input shaft results in rotation of the gear and engaged output shaft. The gear translates actuation of the input shaft into movement of the output shaft. Numerous variations and improvements exist on this concept. 
   Due to the range of lamp assemblies and vehicles, adjusters that can be used in connection with several different lamp assemblies and vehicles are desirable. Most currently available adjusters have a single accessible adjustment point, namely, the input shaft. A range of input shaft configurations are currently available, for example, the Burton &#39;747 patent referenced above discloses an adjuster having an input shaft disposed perpendicular to the output shaft and U.S. Pat. Nos. 6,474,850 and 6,913,374, both to Burton, disclose an adjuster having an input shaft disposed parallel to the output shaft. While the Burton designs are very effective for many applications, they all provide a single adjustment point and require the use of a different adjuster if a different adjustment point location is required for a particular application. As well, they do not provide the flexibility or convenience that would accompany a single adjuster capable of being adjusted at multiple points. 
   Accordingly, a need exists for an improved lamp adjuster that solves these and other deficiencies in the prior art. Of course, the present invention may be used in a multitude of situations where similar performance capabilities are required. 
   SUMMARY OF THE INVENTION 
   The present invention provides a lamp adjuster that is cost-effective, provides improved functionality, and which solves certain of the problems raised or not solved by existing designs. The adjuster of the present invention includes a housing having a first adjustment point, a gear having a second adjustment point and an extended cylindrical portion, an output shaft disposed at least partially within and functionally engaging the extended cylindrical portion and having a ball stud disposed at one end thereof Movement of the output shaft can be effected using either the first adjustment point or the second adjustment point. 
   The adjuster may further include a clutching feature. The clutching feature includes a first threaded portion and a second threaded portion on the output shaft, wherein the first threaded portion has a major diameter greater than that of the second threaded portion, and has a clutching slot disposed thereon. The first threaded portion of the output shaft and the extended cylindrical portion of the gear are in full thread-to-thread engagement and the second threaded portion and the extended cylindrical portion are in minimal engagement. The clutching slot allows the first threaded portion to flex inward and disengage from the extended cylindrical portion in response to excessive resistance to linear movement at any point along the travel path of the output shaft. The minimal engagement between the second threaded portion and the extended cylindrical portion, as opposed to no engagement, supports the output shaft in the extended cylindrical portion to minimize side-to-side deflection of the output shaft. 
   The present invention also contemplates a lamp for a vehicle. The lamp of the present invention includes a lamp housing, a lens supported by the housing, a reflector supported by the housing, a bulb disposed between the lens and the reflector, and an adjuster functionally engaged to the reflector. The adjuster includes a housing, at least two adjustment points, a gear, and an output shaft having a first threaded portion and a second threaded portion, wherein the first threaded portion has a major diameter greater than that of the second threaded portion, and wherein the first threaded portion includes a clutching slot. If desired, the housing of the adjuster may be integrally formed as part of the lamp housing. 
   The adjuster and lamp assembly of the present invention have several advantages over existing adjusters and lamp assemblies. Most significantly, the adjuster can be adjusted from more than one adjustment point, and regardless of which adjustment point is used, the adjuster can include a clutching feature that allows the adjuster to clutch at any point along the travel path of the output shaft. The multiple adjustment points allow the adjuster to be used in a variety of applications, and the clutching feature protects against damage to the adjuster and lamp. Each of the adjustment points can mate with a conventional driver, making the use of the adjuster of the present invention even more flexible. 
   While one possible application of the present invention is in connection with a vehicle lamp, many other applications are possible and references to use in connection with a vehicle lamp should not be deemed to limit the uses of the present invention. The terms used herein should not be interpreted as being limited to specific forms, shapes, or compositions. Rather, the parts may have a wide variety of shapes and forms and may be composed of a wide variety of materials. These and other objects and advantages of the present invention will become apparent from the detailed description, claims, and accompanying drawings. 

   
     DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a front perspective view of an adjuster in accordance with the present invention; 
       FIG. 2  is a rear perspective view of the adjuster of  FIG. 1 ; 
       FIG. 3  is an exploded perspective view of the adjuster of  FIG. 1 . 
       FIG. 4  is a cross-sectional view of the gear and output shaft of  FIG. 1 , taken along plane  4 - 4  of  FIG. 1 ; 
       FIG. 5  is an exploded, partial cross-sectional view of the gear and output shaft of  FIG. 4 ; and 
       FIG. 6  is a cross-sectional view of the adjuster of  FIG. 1 , taken along plane  6 - 6  of  FIG. 1 . 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Referring now to the drawings, an adjuster  10  according to one embodiment of the present invention includes a housing  12 , an output shaft  14 , a gear  16 , and a gasket  18 . The housing  12  includes an input boss  20  and a nose  22  having a set of tangs  32  and a set of tabs  34 . The output shaft  14  includes a first threaded portion  24  at one end thereof, a second threaded portion  26  adjacent the first threaded portion  24 , a ball stud  28  having a recess  44  and disposed at the other end thereof, and a channel  30  that runs along the length of the output shaft  14 . The second threaded portion  26  has a smaller major thread diameter than the first threaded portion  24 , and the first threaded portion  24  has a clutching slot  46  formed therein, as is best shown in  FIG. 5 . The gear  16  has teeth  36 , a head  38 , and an extended cylindrical portion  40 . As best shown in  FIGS. 4 and 5 , the extended cylindrical portion  40  has internal threads  42  along its length. 
   To assemble the adjuster  10  of the present invention, several methods could be used, however the following method has been found to be particularly effective. The gasket  18  is first placed around the nose  22  of the housing  12  and snapped past tabs  34 , which secure the gasket  18  in place. The gasket  18  will serve as a seal between the adjuster  10  and the lamp assembly or mounting hardware in which it is installed. The output shaft  14  is then driven into the extended cylindrical portion  40  of the gear  16  to a desired pre-set position dictated by the lamp assembly and vehicle in which the adjuster  10  will be installed. The recess  44  in ball stud  28  of the output shaft  14  can be used to drive the output shaft  14 . The recess  44  preferably accepts a TORX® head driver, but other driving tools could of course also be used, and the ball stud  28  could be driven without the assistance of a recess  44 . The first threaded portion  24  of the output shaft  14  engages the threads  42  of the extended cylindrical portion  40  of the gear  16  as the output shaft  14  is driven into the gear  16 . The first threaded portion  24  and the threads  42  are in a fully threaded, mating engagement, while the second threaded portion  26  and the threads  42  are in a limited mating engagement because the second threaded portion  26  has a smaller major diameter than the first threaded portion  24 . To continue assembly of the adjuster  10 , a second gasket (not shown) can be placed around the extended cylindrical portion  40  of the gear  16  to create a seal between the housing  12  and the gear  16 . Then, the output shaft-gear  14 - 16  subassembly is pressed into housing  12  such that the ball stud  28  end of the output shaft  14  extends from the nose  22  of the housing  12  and the housing tangs  32  are disposed in the channel  30  of the output shaft  14 . The adjuster  10  can then be installed in a lamp assembly (not shown) such that the ball stud  28  of the output shaft  14  functionally engages the lamp. 
   Once installed, the adjuster  10  can be used to adjust the lamp. An operator can choose between two different points of adjustment using the adjuster  10  of the present invention. A driver can be inserted into the input boss  20  on the top of the housing  12  to mate with the gear teeth  36 . A driver with a Phillips #2 drive bit works well in this application, but other drivers could also be used. The gear teeth  36  can be designed to accommodate a number of different drivers as well. As the selected driver is turned, the gear  16  rotates. Because the output shaft  14  is in threaded engagement with the gear  16  but prevented from rotation by the tangs  32  disposed within channel  30 , the rotation of the gear  16  causes the output shaft  14  to translate linearly. The linear translation of the output shaft  14  effects adjustment of the lamp. Alternatively, the driver or other input shaft could be permanently positioned within the housing  12 . An operator can also use the head  38  of the gear  16  to effect adjustment. The head  38  is preferably hexagon-shaped to mate with a ½″ hex socket, but other shapes and tools could also be used to turn the head  38 . Turning the head  38  turns the gear  16 , which, in the same manner described above, causes the output shaft  14  to translate linearly, thereby effecting adjustment of the lamp. Thus, the adjuster  10  of the present invention can be adjusted in two different ways, from two different adjustment points. In the embodiments shown, the adjustment points are oriented perpendicular to one another, which will allow the adjuster to be used in a wide range of applications, however, the adjustment points could be positioned at other locations and angles with respect to one another as well. 
   Using either adjustment method, the adjuster  10  includes a clutching feature to prevent damage to the adjuster as a result of over-adjustment, excessive torque application, or other resistance to the linear movement of the output shaft  14 . The difference between the major thread diameters of the first threaded portion  24  and the second threaded portion  26  combined with the clutching slot  46  disposed within the first threaded portion  24  allow the output shaft  14  to clutch along the entire length of travel, regardless of which adjustment point is used. As previously described, the major thread diameter of the first threaded portion  24  is larger than that of the second threaded portion  26 . The first threaded portion  24  spans a smaller section of the length of the output shaft  14  as well. For example, as shown in  FIG. 5 , the first threaded portion may contain only a few threads, while the second threaded portion may contain about twenty threads. One possible major thread diameter for the first threaded portion  24  is ⅜″, and more specifically a ⅜-16 UNC Class 3A thread. Other numbers, diameters and types of threads for each portion  24 ,  26  could also be used as necessary for each application. It is also possible to use an unthreaded portion in place of the second threaded portion  26 , however, a second threaded portion  26  is preferable, as described below, to support the output shaft  14  in the extended cylindrical portion  40  and prevent side-to-side deflection of the output shaft  14 . 
   In operation, the first threaded portion  24  is in full thread-to-thread engagement with the threads  42 , and the second threaded portion  26  is minimally engaged with threads  42  to provide adequate support between the second threaded portion  26  and the internal threads  42  to minimize side-to-side deflection of the output shaft  14 . When the adjuster is over-adjusted, or subjected to excessive torque or force at any point along the output shaft  14 , the slot  46  in the first threaded portion  24  allows the first threaded portion  24  to flex inward and disengage from the threads  42  and thereby prevent damage to the adjuster or lamp. Once the excessive torque or load is relieved, the first threaded portion  24  flexes back outward to reengage the threads  42 . This engagement and disengagement can occur at any point as the output shaft  14  travels forward and backward in the extended cylindrical portion  40  of the gear  16 . Thus, the adjuster  10  is protected not only from excessive torque or loads applied when the output shaft  14  is at either end of the travel path, but at any time an excessive torque or load is applied. 
   The housing  12 , output shaft  14  and gear  16  can be manufactured from plastic materials, making them very lightweight and inexpensive to produce. Other materials could also be used, such as metal and composite materials, but lightweight and inexpensive materials are preferred. The gaskets can be manufactured from a number of different materials, including rubber and silicone materials. 
   The adjuster  10  of the present invention may have other applications aside from use in connection with vehicle lamp assemblies. Although the invention has been herein shown and described in what is perceived to be the most practical and preferred embodiments, it is to be understood that the invention is not intended to be limited to the specific embodiments set forth above. Rather, it is recognized that modifications may be made by one of skill in the art of the invention without departing from the spirit or intent of the invention and, therefore, the invention is to be taken as including all reasonable equivalents to the subject matter of the appended claims.