Assembly for Headlamp Adjustment

The present invention relates to adjusting mechanism for alignment of automobile headlamps or the like, and more particularly relates to an improved assembly and construction of such mechanisms.

Particularly successful modern adjusting mechanism for alignment of vehicle headlamps are described for example in U.S. Pat. Nos. 4,674,018 and 4,893,219. In the described mechanisms, an adjusting screw is coupled to the headlamp housing and extends into a gear box or adjustment mechanism. The adjusting screw is operatively coupled to an adjusting drive shaft which is operated by conventional hand tools, by means of a pair of mitered gears and a threaded connection. The gear members can be assembled and sealed within the integral gear housing, while allowing the drive shaft and adjusting screw components to be assembled at a later time with a variety of shaft and screw lengths as required for different model automobiles.

The gear assembly of the adjusting mechanism described in these patents has been enclosed within two-part or three-part housing structures which are assembled and joined by ultrasonic welding or adhesive bonding. The present invention provides simplified assembly of the housing in such headlamp adjusting mechanism as well as simplified mounting of the adjusting mechanism on the supporting structure of the vehicle in which the headlamp is installed.

In accordance with the present invention, an adjusting mechanism for alignment of a vehicle headlamp or the like includes a molded housing in which a pair of mitered gears are journaled and movably coupled to an adjusting member so that rotation of the gear members imparts linear movement to the adjusting member for changing the vertical or horizontal orientation of the headlamp. The housing includes first and second portions thereof which are joined by clamping the second housing portion between the first housing portion and a support structure to which the adjusting mechanism is secured. Clamping structure is integrally provided on the first housing portion and secured directly to the support structure so that separate mounting fasteners are eliminated.

In a preferred embodiment, the first housing portion includes a plurality of resiliently deflectable coupling hooks projecting therefrom. The coupling hooks extend beyond the second housing portion which forms a cap to close the journaling bore for the adjusting gear. The extension of the coupling hooks enables the hooks to be resiliently deflected and inserted through receiving aperture in a supporting panel of the vehicle so that the hooks are snap-fitted against peripheral edges of the aperture in locking engagement to retain the clamped securement of the cap between the main first housing portion and the panel. The resulting clamped assembly eliminates any need for bonding or ultrasonic welding of the cap to the housing.

FIG. 1 is a side elevational view of one embodiment of the adjusting mechanism according to the invention coupled for adjustment of a headlamp alignment;

FIG. 2 is an exploded perspective view of the adjusting mechanism shown in FIG. 1;

FIG. 3 is a sectional view of the adjusting mechanism shown in FIGS. 1 and 2; and

FIG. 4 is a sectional view of the adjusting mechanism at a plane through line 4--4 in FIG. 3, in which the housing cap portion of the adjusting mechanism in FIG. 3 has been omitted for clarity of the remaining sectional view.

Referring to FIG. 1, an embodiment of the adjusting mechanism according to the invention, designated generally by reference character 10, includes an adjusting screw 12 which has its distal end affixed to the headlamp housing 14 which holds the headlamp assembly designated generally 16. The adjusting mechanism 10 is mounted on a panel 17 of the vehicle (not shown) as more fully described hereinafter. In the illustrated embodiment the adjusting screw 12 is fixed against rotation and thus can only move linearly in response to rotation of the internal gearing within the mechanism 10. The linear motion of the screw 12 generated by the mechanism 10 causes the headlamp housing 14 to pivot through an arc 18 about a pivot bearing 19 in order to adjust the vertical alignment of the headlamp 16 in the configuration shown in FIG. 1. In practice, additional adjusting mechanisms 10 are employed to attain horizontal adjustment of the headlamp.

Referring now to the exploded view in FIG. 2, the adjusting mechanism 10 includes a unitary molded main housing 20 within which a main cavity 22 is formed. The cavity 22 has an internal structure providing multiple shoulders and ledges which define a pair of intersecting gear-journaling bores or chambers which receive a bevel-meshed drive gear and adjusting gear generally designated by respective reference numerals 24 and 26. The gears 24 and 26 are mitered gears and are of relatively standard design.

The adjusting gear 26 has a central, internally threaded bore 26a in which the externally threaded adjusting screw 12 is engaged, and projects from both ends thereof as well as translating through the housing 20 as indicated in FIGS. 1 and 3.

As best shown in FIG. 3, the drive gear 24, which drives the adjusting gear 26, is coupled to one end of a drive shaft 28 having a drive head 28a which can be turned by suitable tooling such as a screwdriver (not shown). The drive gear 24 preferably has multi-lobular configured coupling recess which receives the mating end of the drive shaft 28 as more fully described in my aforementioned, co-pending application Ser. No. 517,232.

In alternative embodiments, the drive shaft and drive gear can be integrally molded to eliminate the need for coupling, or the drive shaft can be insert molded into the gear, and in either modification the bearing of the cap tongue against the shaft flange will prevent withdrawal of the drive shaft as well as provide vibrational stability of the drive gear and the meshed adjusting gear.

In assembling the adjusting mechanism 10, the coupling end of the drive shaft 28 is inserted into the drive gear 24, after which the drive gear 24 is slidably inserted into the gear receiving bore of the cavity 22 so that the shaft 28 projects through the open slot 20a in the upper wall of the housing 20. Then the adjusting screw 26 can be inserted into the cavity 22 meshing with the drive gear 24. A housing cap member 40 is then installed on the main housing 20 to close the cavity 22 and engage the back of the adjusting gear 26 to maintain the meshing of the gears 24 and 26. A bonding operation to ultrasonically weld or otherwise bond the cap 30 to the main housing 20, can be eliminated, and simplified joining of the cap 30 and main housing 20 is maintained by clamping the cap 30 between the main housing 20 and the structural panel 17 or similar wall of the vehicle adjacent the headlamp housing 14. The clamp joint is achieved in the illustrated embodiment by providing the main housing 20 with three rearwardly projecting, hooked couplers 32, 34 arranged in a pattern in which one coupler 32 projects from the bottom of the housing 20 and a spaced pair of couplers 34 project from the upper wall of the housing 20 straddling the slot 20a as best shown in FIG. 2. The couplers 32, 34 project generally perpendicular to the cavity-closing wall of the cap 30, and are resiliently deflectable to enable a snap-fit installation through a coupling aperture 17a formed through the panel 17. The hooked couplers 32, 34 thus lock against the peripheral surfaces 17b of the aperture 17a to clamp the cap 30 against the main housing 20 and the panel 17 as best shown in FIGS. 3 and 4. The couplers 32,34 also provide three locations of locking securement to prevent any rotation of the mechanism 10.

In the illustrated embodiment, the adjusting screw 12 is prevented from rotating and is capable of translational motion only, upon rotation of the adjusting gear 26; to prevent rotation, the adjusting screw 12 has a fabricated configuration with a non-circular cross-section, and in the illustrated embodiment, the screw 12 has a cruciform cross-section. The cap 30 is provided with an aperture which allows translational passage of the screw 12 therethrough for proper pivotal motion of the headlamp housing 14, however, the aperture 30a has a configuration including a radially extending slot 30b which receives one arm 12a of the cruciform cross-section of the screw 12 to provide the rotational interference which guides only translational motion of the screw 12 during the adjustment operation. Preferably, the front wall 20b of the main housing 20 also has a screw aperture 21 and configuration which provides rotational interference with the screw 12 while allowing translational passage to ensure that the screw 12 cannot rotate which could otherwise cause aberant force tending to misalign the pivot bearing 19. Suitable modifications of the cruciform cross-sectional configuration of the screw and corresponding housing apertures can be employed to prevent rotation of the screw.

Referring again to FIGS. 2 and 3, in the illustrated embodiment, the drive shaft 28 includes an annular, radially projecting retainer flange 29 (FIG. 3) which fits within a recess in the drive gear 24 and is retained therein by the upper wall of the housing 20 and the bottom surface of the forwardly projecting tongue portion 31 of the cap 30, as more fully described in my aforementioned application Ser. No. 517,232. The tongue 31 closes the slot 20a and also includes an upstanding, arcuate portion 31a which forms one-half of a split journal with portion 23 of the housing 20, to promote supporting alignment of the drive shaft 28. The tongue portion 31 also includes a support flange 33 rearwardly extending from the arcuate, journaling portion 31a to ensure rigidity thereof.

While particular embodiments of the present invention have been described herein, it will be obvious to those skilled in the art that changes and modifications in various aspects may be made without departing from the broad scope of the invention. Consequently, the scope of the invention is not limited by any particular embodiment but is defined by the appended claims and the equivalents thereof.