Gear screw adjuster

A headlamp assembly including a simplified adjusting mechanism for adjusting the aim of the headlamp. The mechanism includes a gear screw that is snap fit into the headlamp housing with or without an adjuster housing. The gear screw has an O-ring in radial compression so as to ensure a good seal.

BACKGROUND OF THE INVENTION

This invention relates generally to adjusting devices, and in particular to a gear screw adjuster used in connection with motor vehicle headlamps.

As the design of vehicles, automobile, and light trucks in particular, has evolved, headlights have continually been reconfigured to improve the aerodynamics of the front end of the vehicle. Modern headlights are designed so that their lenses follow the contour of the vehicle to provide an aerodynamically efficient exterior surface. However, adjustment of these headlights must still be performed in order to provide an optimal beam of light and to prevent the aiming of light beams toward oncoming vehicles. Automotive manufacturers' demand for aerodynamically efficient headlight designs has lead to modular designs requiring the headlight adjustment mechanism to be located within the interior of the engine compartment so that adjustment can be easily performed without removing any exterior trim pieces. Thus, the constraints of the installation area and the demands of the automobile manufacturers for aerodynamic headlight designs make it desirable to provide an adjuster for use with the aerodynamic designs that is adjustable from inside the engine compartment using ordinary tools, and translates rotational motion of the adjusting part into adjustment of the reflector within the headlight assembly. There are a wide variety of prior art adjuster devices including, among others, the devices disclosed in U.S. Pat. Nos. 5,707,133 and 5,214,971 to Burton, the inventor of the present invention, the disclosures of which are incorporated herein by reference.

As disclosed in FIGS. 17 and 23 of U.S. Pat. No. 6,247,868, the disclosure of which is incorporated herein by reference, automotive lamp assemblies used as headlights typically comprise several basic parts: a support frame, a reflector, a lens, a bulb, and one or more adjusters. The support frame houses the reflector and the bulb on a pivotable mounting to allow the aim of the light to be adjusted using the adjuster. The lens seals the front of the assembly to protect it from the elements assailing the front end of the vehicle and provides an aerodynamic shape and attractive appearance. Traditionally, fixed and moveable ball joints have engaged the headlamp reflector. Actuating the moveable ball joint would result in altering the angle of the headlamp reflector by pivoting the headlamp about the fixed ball joints. In certain variations, two moveable ball joints are used to enable vertical and horizontal aiming of the headlamp.

In some instances, an aiming or gear screw replaces the moveable ball joint. With the screw assembly, the reflector mounts inside the housing on a gear screw assembly and is adjustable horizontally and/or vertically using adjusters that interface with the reflector by moving the gear screw. One such a screw assembly is disclosed in U.S. Pat. No. 5,444,603 to Otsuka et al. In order to securely hold the headlamp in the desired position, additional parts must be added to the aiming screw. As shown in FIG. 10 of the Otsuka Patent, a push-on fixer 10 is added to the aiming screw 20 after the screw 20 is inserted through the headlamp housing 1. Using a push-on fixer requires steps in addition to merely inserting the screw through the headlamp housing.

The Otsuka Patent also discloses the use of an O-ring 9a and plastic washer 96 or wave washer 8 to attempt to effect a seal between the headlamp housing 1 and the flange 24 of the screw 20 to control screw torque, and to control axial screw backlash. Such a configuration places the O-ring and washers in facial compression, the amount of which will very as a result of the individual part tolerances. Such variations in facial compression has been found problematic in that it can cause wide variations in screw torque and can result in inadequate sealing.

Accordingly, the need exists for a compact gear screw adjuster assembly that can be securely retained in a wall or other structure of the headlamp housing, can be adapted for use in connection with various headlamp housing and headlamp reflector designs, is more efficient and cost effective to assemble to the headlamp housing, and reduces the sealing problems associated with facially sealing O-rings. Of course, the present invention may be used in a multitude of non-automotive lamp situations where similar performance capabilities are required.

SUMMARY OF THE INVENTION

The present invention provides a gear screw adjuster assembly that is cost-effective, easily installed in the lamp where it is securely retained, provides an improved seal reduces screw torque variation, and which solves the problems raised or not solved by existing designs. In one embodiment, the gear screw directly snap fits into the headlamp housing. In some embodiments, the gear screw is first inserted into an adjuster housing. Then, the screw and adjuster housing are together snap fit into the headlamp housing. In another embodiment, the gear screw is snap fit into the adjuster housing which engages the headlamp housing in the well-known quarter-turn fashion. After the gear screw, and any accompanying adjuster housing, has engaged the headlamp housing, the reflector of the headlamp assembly is positioned to engage the gear screw. The gear screw is threaded so that rotation of the gear screw translates the reflector into the correct position.

In addition, the gear screw adjuster assembly achieves a substantially improved seal between the headlamp reflector and the headlamp housing while reducing screw torque variation. The present invention achieves a radial compression seal around the O-ring. Such a radial compression seal is accomplished by controlling the diameter of the screw and inner diameter of the housing. The result is less variation in seal compression, reduced screw torque variation, and improved sealing as opposed to the conventional facial seal.

In one embodiment of the present invention, the gear screw assembly can be securely inserted and retained in the headlamp housing without the additional step of adding a push-on fixer to the screw engagement as is required in certain conventional adjusters. Alternatively, the gear screw may be first snap fit into an adjuster housing which is then inserted and engaged in the headlamp housing in the traditional quarter turn fashion or other manner.

While one possible application of the present invention is in headlamp assemblies, many other applications are possible and references to use in a headlamp assembly should not be deemed to limit the uses of the present invention. The terms “housing,” gear screw,” “threading,” or “teeth” as used herein should not be interpreted as being limited to specific forms or shapes of screws, threading thereon, or teeth. Rather, the housing, gear screw, threading, and teeth of the gear screw assembly in accordance with the present invention may have a wide variety of shapes. These and other objects and advantages of the present invention will become apparent from the detailed description, claims, and accompanying drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Three illustrative embodiments of a gear screw adjuster assembly (identified generally as 1) in accordance with the present invention are shown inFIGS. 1 through 17. While the invention may be susceptible to embodiment in different forms, there is shown in the drawings, and herein will be described in detail, certain illustrative embodiments with the understanding that the present disclosure is to be considered an exemplification of the principles of the invention, and is not intended to limit the invention to those as illustrated and described herein. Additionally, features illustrated and described with respect to one embodiment could be used in connection with other embodiments.

FIG1shows a headlamp assembly11whereby the desired aiming of the headlamp as indicated by an arrow7is achieved by actuating a gear screw adjuster assembly1. The headlamp assembly11comprises many parts, including but not limited to, a housing9, a moveable reflector3, a lens51, and the requisite lamp and wiring53.

The adjuster mechanism1is used to adjust the movable reflector3. A single adjuster mechanism1can be used to adjust the reflector3in either the horizontal or the vertical direction, while another similar adjuster mechanism may be used if adjustment in both dierctions is desired.

In one embodiment, the adjuster mechanism1is assembled and inserted through a stationary component of the headlamp assembly11such as the housing9and is engaged with the reflector3. The adjuster mechanism1includes an adjusting or gear screw13, an O-ring15, and a retaining clip17for securely holding the gear screw13in the headlamp housing. The adjuster mechanism1is shown in detail inFIG. 4. The gear screw13may be made of a plastic material by appropriate manufacturing methods such as molding or casting. Alternatively, the gear screw may be made of metal material by appropriate manufacturing methods.

The gear screw13also provides for an O-ring15to be located along its neck45. The neck45may have an O-ring groove in which the O-ring15is located. This configuration maintains the position of the O-ring15as the gear screw13is snap fit into the housing9. The O-ring15remains in the groove while the screw13travels through the housing9and while the screw13is rotated. As shown inFIGS. 1,3and5, the O-ring15functions to create a radial seal in the neck21of the housing9in which the gear screw13is positioned. The reinforced neck21has an interior diameter47so that the neck21exerts a radial force along the outer diameter of the O-ring15once the gear screw13has been snap-fit and secured in the housing9. This force creates a radial compression of the O-ring15. As such, a complete radial seal is created between the neck21of the housing9and the O-ring15and between the neck45of the gear screw13and the O-ring15.

There are the two methods that have been found effective for securing the gear screw13in the reinforced neck21but other methods may be used.FIG. 5shows one such method using a retainging clip17on embodiment of which is shown in detail inFIG. 4A. The retaining clip17, like the O-ring15, is positioned in a groove49located along the neck45of the screw13. As the screw13is pushed into the reinforced neck21, the retaining clip17is compressed into the clip groove49. The interior diameter47of the neck21is angled so that the clip17contacts the interior diameter47as the gear screw13is inserted into the neck21. As the gear screw13passes through the neck21, the interior diameter47of the neck compresses the retaining clip17into the clip groove49. The interior diameter47of the neck21provides sufficient space to allow the retaining clip17to expand once the gear screw13is inserted into the neck21in the correct position. As such, the retaining chip17“pops” open once the gear screw13reaches the correct position. Snap fitting the gear screw13into the headlamp housing9provides an easy way to ensure the gear screw13is properly and securely positioned in the headlamp housing9. The retaining clip17may be made of plastic, metal, or other material.

One alternative method for the gear screw13to securely engage the reinforced neck21is illustrated inFIG. 14. This method involves snap fitting the gear screw13into the housing9whereby the gear screw13itself provides the securing method. The diameter75of the gear screw13increases over an area77of the screw shaft19between the threads27and the neck45. Immediately after this area77is an undercut section73. The diameter of the undercut section is less than that of the area77or the neck45. The headlamp housing9has an orifice (not shown) that will flex to accommodate the increased diameter area77. The input shaft19is inserted into the orifice. As the area77travels through and contacts the orifice, the orifice expands to accommodate the increased diameter75. Once the area77passes through the orifice, the orifice diameter decreases as the undercut section73is now in contact with the orifice. The reduced diameter of the undercut section73as compared to that of the area77and the neck45maintains the position of the gear screw13in the housing9by the orifice securely engages the undercut section73.

The gear adjuster assembly1is assembled by pushing the gear screw13, accompanying O-ring15, and retaining clip17through the interior diameter47of neck21, through the reinforced neck21of the housing9. The completed assembly is shown inFIG. 5. The screw shaft19extends through and beyond the reinforced neck21. The end of the screw shaft19is threaded so as to insert into and rotatably engage the reflector3. This engagement is shown inFIGS. 1–3. Such engagement can occur directly between the threads27and the reflector3or a nut or grommet, such as the nut disclosed in U.S. Pat. No. 5,746,559 and the grommet shown inFIGS. 7 and 8can be used. The reflector3has a slot31that engages the threads27as shown inFIG. 3. The slot31may be made of a plastic material or made of metal and is preferably molded as part of the reflector3. Alternatively, the slot31may be a separate piece that is attached by molding, bracketing, welding, or the like to the reflector3.

The slot31on the reflector3is constructed to complement the threading27. This construction may be accomplished by using a plurality of fins33positioned in a staggered fashion so that rotation of the screw shaft19engages the fins33in such a manner so that the reflector3may be translated into the proper position. The slot31is constructed to allow the reflector3to move as the screw shaft19is rotated. Alternatively, as shown inFIGS. 7 and 8, the engagement of the screw shaft19with the reflector3can be accomplished indirectly by having the screw shaft19first engage a complementary threaded grommet29. In such alternative, the threads27engage a grommet29and the grommet29is then inserted into the slot31or other receiving orifice of the reflector3.

Once the screw shaft19is snap fit through the reinforced neck21and engages the reflector3, the gear screw13is rotated thereby translating the reflector3so that the reflector is correctly positioned. Such rotation is accomplished by any number of conventional drive tools such as hexagonal, TORX® drive, or the like. This drive tool is inserted into a recess35in the head37of the gear screw13. The head37also has a flange55. The shoulder39of the gear screw13fits within the neck21.

Additional adjustment of the aim7of the headlight is often required after the headlamp has been initially adjusted as described above. Such adjustment is necessary after accidents involving front-end damage, major engine repair, or as a result of routine gyrations and wear and tear. The person doing such adjustment often can not access the head37of the gear screw13to rotate the gear screw13as described. The person performing the additional adjustment can do so by inserting a driver5into the access shaft23wherein the driver5engages a gear teeth portion25of the gear screw13. In the embodiments shown in FIGS.1and4–6, the gear teeth25protrude in the forward direction. It is to be understood, however, that the gear teeth25may also protrude in the rearward direction. The driver5may be a flathead, Phillips head, TORX® head, hexagonal head driver, or the like, depending on the configuration used for the gear teeth.FIGS. 1 and 6show use of a driver5to adjust the aim7of the headlamp.

Alternatively, a permanent driver input shaft (not shown) may be inserted in the access shaft23. The head of the shaft may be configured to complement a driver. The gear engagement end (not shown) is configured to complement the gear teeth25. Actuation of the driver5while the driver5is engaged, either directly or indirectly via the permanent driver input shaft, with the gear25results in rotation of the gear screw13and movement of the reflector3into the correct position. Such rotation allows the person actuating the driver5to properly position the aim7of the headlamp.

In one alternative embodiment of the invention, as shown inFIGS. 7–11, the gear screw13interacts with an adjuster housing57, as well as the headlamp housing9and the reflector3. The gear screw13has the same configuration as in the previously described embodiment and interacts with the headlamp housing9and the reflector3in the same fashion.FIG. 10shows the configuration of the gear screw13.FIGS. 7–9show the interaction of the gear screw13with the reflector3. In this embodiment, the gear screw13is first inserted through the adjuster housing57.FIG. 11shows the adjuster housing. The adjuster housing57has an opening59of a diameter61greater than that of the screw shaft19of the gear screw13and that of the neck45of the gear screw13. The diameter61is less than that of the gear portion25of the gear screw13and is less than the shoulder39of the gear screw13. In addition, the adjuster housing57has a recessed inner ledge63. This construction allows the screw shaft19and the neck45to pass through the adjuster housing57. The recessed inner ledge63comes into contact with and engages the shoulder39of the gear screw13. The flange55of the gear screw13comes into contact with and engages the rear lip65of the adjuster housing57. The gear screw13can be fully rotated inside the adjuster housing57after it has been inserted therein.

In this embodiment, the adjuster housing57, and not the headlamp housing9, provides for the access shaft23for post assembly headlamp adjustment. The adjuster housing57has an access shaft23as shown inFIGS. 7–11. In this embodiment, the driver5itself may be inserted into the access shaft23and thereby directly engage the gear portion25. The gear portion25is notched to complement a driver so as to be actuated by operating the driver5.

Alternatively, as shown inFIGS. 7–9, a driver input shaft67may be placed in the access shaft23. The head69of the input shaft67is shaped to correspond with a driver5. The gear engagement end71of the input shaft67is shaped so as to functionally engage the gear25. This engagement is shown inFIG. 10. As such, actuation of the driver rotates the input shaft67which in turn rotates the gear screw13. As above, rotation of the gear screw13translates the reflector3so that the aim7of the headlamp can be correctly positioned.

The mating geometry of the housing9is designed to accommodate the gear screw13and accompanying adjuster housing57so that the gear screw13can be first inserted into the adjuster housing57and then snap fit into the headlamp housing9. The headlamp housing9also includes a nest (not shown) to orient and prevent rotation of the adjuster housing57and the access shaft23so that the access shaft23can be easily reached after the headlamp assembly11is installed in a vehicle.

In another embodiment of the present invention, shown inFIGS. 12–17, the gear screw13, as in both previous embodiments, has a threaded27screw shaft19, a neck45, a shoulder39, a gear portion25, and a screw head37with a recess35. An O-ring15is located in an O-ring groove along the neck45. As shown inFIG. 14, the neck45has an undercut section73on the screw shaft19. The diameter75of the gear screw13increases in the area77between the threads27and the undercut section73. The undercut section73has a diameter less than that of the neck45and less than that of the area77.

The gear screw13and accompanying O-ring15are snap-fitted into an adjuster housing57as shown inFIG. 16. The adjuster housing57has a recessed inner ledge (not shown inFIG. 16) against which the shoulder39will abut once the gear screw13is properly fit into the housing57. The housing has a slightly expandable neck portion79that is slotted81for snap fitting. As the screw shaft19passes through the opening59of the adjuster housing57, the increasing diameter75of the screw13comes into contact with the interior of the frontal portion79. The opening59dilates to accommodate the increasing diameter75in contact with the neck portion79. This dilation is accomplished by the diameter75forcibly expanding the slots81. Once the undercut section73passes through the neck portion79, the size of the opening59decreases as a result of the smaller diameter of the undercut section73contacting the interior of the neck portion79. As such, the gear screw13is pushed through the adjuster housing57with the opening59of the neck portion79expanding to accommodate the increasing diameter75of the screw until the diameter of the gear screw13decreases in the undercut section73thereby allowing the neck portion79to snap close around the undercut section73.

Alternatively, a retaining clip17, as previously described may be used to snap the gear screw13into the adjuster housing57. Here, inserting the gear screw13into the adjuster housing57causes the retaining clip17to be compressed into a corresponding groove49in the neck45of the gear screw13. The interior of the adjuster housing57is contoured so that the retaining clip17snaps open and securely engages the adjuster housing57once the gear screw13is fully inserted in the adjuster housing57in the proper position.

The adjuster housing57can engage the headlamp housing9in the known quarter turn fashion or using other method known in the art. The quarter turn engagement is shown inFIG. 15. The neck portion79of the adjuster housing57has a plurality of quarter turn lugs83on its exterior. These lugs83geometrically mate with orifices in the headlamp housing9. After the gear screw13is snap-fit into the adjuster housing57, the adjuster housing57is positioned so that the lugs83enter matching orifices in the headlamp housing9. Upon the lugs83fully entering the corresponding orifices, the headlamp housing9abuts the gasket85on the neck portion79and the flat front87of the adjuster housing. Once the lugs83have entered the corresponding orifices, the adjuster housing57is turned approximately up to one quarter or 90°. As shown inFIG. 15A, the O-ring15is radially compressed between the neck portion79and the O-ring groove on the neck45of the gear screw13. The result is an effective radial seal between the interior diameter47of the adjuster housing57and the O-ring15and between the O-ring and the neck45of the screw13.

Once the neck portion79of the adjuster housing57has mated with the headlamp housing9as shown inFIG. 15, the reflector is positioned in the same manner as previously described. This positioning involves using a driver5to functionally engage the recess35in the screw head37.FIG. 12shows the gear screw13snap fit into the adjuster housing57and the housing57quarter turn inserted into the headlamp housing9so that a driver5may engage the recess35. Actuation of the driver rotates the gear screw13thereby translating the reflector3into the correct position.

The gear screw adjuster assembly of the present invention may have other applications aside from use in a lamp assembly. 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.