U.S. patent application number 09/757724 was filed with the patent office on 2001-10-18 for headlamp adjuster configured to prevent over-travel of an adjuster output shaft.
Invention is credited to Denley, Ronald S..
Application Number | 20010030875 09/757724 |
Document ID | / |
Family ID | 26864530 |
Filed Date | 2001-10-18 |
United States Patent
Application |
20010030875 |
Kind Code |
A1 |
Denley, Ronald S. |
October 18, 2001 |
Headlamp adjuster configured to prevent over-travel of an adjuster
output shaft
Abstract
A headlamp adjuster which includes an adjuster output shaft
which is engageable with a reflector of a headlamp assembly. The
adjuster output shaft extends from a housing, and the headlamp
adjuster is configured such that in an overload condition, the
adjuster output shaft is prevented from translating substantially
axially, thereby reducing the risk of damage resulting from
over-travel of the adjustor output shaft.
Inventors: |
Denley, Ronald S.;
(Woodstock, IL) |
Correspondence
Address: |
TREXLER, BUSHNELL, GIANGIORGI,
BLACKSTONE & MARR, LTD.
105 W. ADAMS ST.
CHICAGO
IL
60603
US
|
Family ID: |
26864530 |
Appl. No.: |
09/757724 |
Filed: |
January 10, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09757724 |
Jan 10, 2001 |
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09690486 |
Oct 17, 2000 |
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60168865 |
Dec 3, 1999 |
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Current U.S.
Class: |
362/514 ;
362/282; 362/284; 362/322; 362/324 |
Current CPC
Class: |
B60Q 1/0683
20130101 |
Class at
Publication: |
362/514 ;
362/282; 362/284; 362/322; 362/324 |
International
Class: |
F21W 11/10 |
Claims
What is claimed is:
1. A headlamp adjuster for adjusting a position of a reflector of a
headlamp assembly, said headlamp adjuster comprising: a housing; an
adjuster output shaft which extends from and is engageable with the
reflector of the headlamp assembly, said adjuster output shaft
being extendable and retractable; a first stop member generally
engaged with said adjuster output shaft and engageable with a
surface of said housing when said adjuster output shaft is
retracted; and a second stop member generally engaged with said
adjuster output shaft and engageable with a surface when said
adjuster output shaft is extended, wherein said headlamp adjuster
is configured such that in an overload condition, the adjuster
output shaft is prevented from translating substantially
axially.
2. A headlamp adjuster as recited in claim 1, further comprising an
overload clutch mechanism, said overload clutch mechanism
configured to generally prevent said adjuster output shaft from
being over extended or over retracted.
3. A headlamp adjuster as recited in claim 1, further comprising an
output gear engaged with said adjuster output shaft and an input
gear engaged with said output gear.
4. A headlamp adjuster as recited in claim 1, further comprising a
tower engaged with said housing, said adjuster output shaft
generally extending into said housing, said first stop member
engageable with said surface of said housing when said adjuster
output shaft is retracted such that said adjuster output shaft does
not contact said tower.
5. A headlamp adjuster as recited in claim 1, further comprising at
least one static detent which is generally in the housing; and a
bushing disposed generally in the housing and having an opening,
said adjuster output shaft extending through said opening in said
bushing, said bushing providing at least one flexible detent which
is engaged with said at least one static detent.
6. A headlamp adjuster as recited in claim 5, said headlamp
adjuster configured such that said adjuster output shaft and said
bushing are not generally rotatable in said housing unless said
first stop member on said adjuster output shaft is in contact with
said surface of said housing or said second stop member on said
adjuster output shaft is in contact with said surface.
7. A headlamp adjuster as recited in claim 1, further comprising a
clutch bushing engaged with said adjuster output shaft; an output
gear engaged with said clutch bushing; and an input gear engaged
with said output gear.
8. A headlamp adjuster as recited in claim 7, said headlamp
adjuster configured such that said clutch bushing is slippable
relative to said output gear to prevent substantial axial
translation of said adjuster output.
9. A headlamp adjuster as recited in claim 8, further comprising a
friction coupling member engaged with said clutch bushing and with
said output gear.
10. A headlamp adjuster as recited in claim 1, wherein said
adjuster output shaft includes a ball portion, said first stop
member generally engaged adjacent said ball portion when said
adjuster output shaft is retracted.
11. A headlamp adjuster as recited in claim 1, wherein said
adjuster output shaft includes a ball portion, and said first stop
member comprises a collar stop which is generally engaged adjacent
said ball portion when said adjuster output shaft is retracted.
12. A headlamp adjuster as recited in claim 1, wherein said second
stop member comprises a retaining member which is crimped onto said
adjuster output shaft.
13. A headlamp adjuster as recited in claim 1, wherein said
adjuster output shaft includes a ball portion and said ball portion
has a qualified thread coating thereon.
Description
BACKGROUND
[0001] The present invention relates generally to headlamp
adjusters which are used to adjust the position of a reflector of
an automobile headlamp assembly, and relates more specifically to a
headlamp adjuster which includes an overload clutch mechanism.
[0002] Modern day headlamps for vehicles are engineered and
designed to be aerodynamically efficient. In this regard, the
headlamps are designed as sealed assemblies wherein the portion of
the headlamp approximate the outer surface of the automobile is
relatively stationary, and is aerodynamic.
[0003] A typical modern day headlamp assembly 12 is illustrated in
a plan view seen as FIG. 1, and normally includes: a fixed housing
20, to which an outer headlamp lens 22 is affixed; a movable
reflector 24, which is mounted within the fixed housing 20; and a
stationary headlamp bulb (not shown), which is positioned within
the movable reflector 24. Typically, the movable reflector 24 is
mounted to the housing 20 by a universal or ball-type pivot 26
which is stationary, or fixed, on the housing 20.
[0004] A first pivot point 28 is disposed generally vertical of the
fixed pivot 26, and a second pivot point 30 is disposed generally
horizontal of the fixed pivot 26. As such, the movable reflector 24
may be pivoted about the fixed pivot 26 in the vertical and
horizontal planes to aim the headlamp beam. Adjustment mechanisms,
or headlamp adjusters, 40 and 42 are typically provided at the
first and second pivot points, 28 and 30, normally termed the
vertical pivot and the horizontal pivot, and the headlamp adjusters
40 and 42 can be operated to effect movement of the reflector 24 in
the vertical and horizontal planes.
[0005] The headlamp adjusters 40 and 42 are typically mounted to
the housing 20 of the headlamp assembly 12 and have adjuster output
shafts 44, 46 operatively connected to the movable reflector 24 by
ball and socket type pivots, or the like, such that linear movement
of the adjuster output shafts 44, 46 produces pivoting of the
movable reflector in the vertical and horizontal planes.
Specifically, each headlamp adjuster 40, 42 typically includes
drive structure 48, 50 for receiving a tool, and typically the
drive structure 48, 50 is precision geared to the adjuster output
shaft 44, 46. The gearing provides that using the tool to rotate
the drive structure 48, 50 causes linear translation of the
adjuster output shaft 44, 46 and therefore adjustment of the
position of the headlamp reflector 24.
[0006] Before an automobile is released to the consumer, the
movable reflectors of the headlamp assemblies are adjusted to a
desired position so that the headlamp beams are properly aimed in
both the vertical and horizontal directions. To this end, headlamp
adjusters are normally operated at the automobile assembly plant.
Thereafter, if a movable reflector moves from its desired position,
due, for example, to vibration, jarring, or the vehicle being in an
accident, a mechanic can operate the headlamp adjusters in order to
properly re-align the reflectors.
[0007] Typically, headlamp adjusters are structured such that
over-travel of the adjuster shafts (i.e. 44 in FIG. 1) is not
prevented. Over-travel of the adjuster shaft can cause breakage of
the headlamp adjuster housing and/or the reflector to which the
adjuster shaft is connected. Specifically, over-extension of the
adjuster screw from the housing can damage the reflector, and
over-retraction of the adjuster screw into the housing can cause
the end of the adjuster screw to contact an interior wall of the
housing and result in damage to the housing, such as cracking. A
crack in the housing can permit moisture, dirt, etc. to enter the
housing which is undesirable.
OBJECTS AND SUMMARY
[0008] Accordingly, it is an object of an embodiment of the present
invention to provide a headlamp adjuster which is structured such
that over-travel of the adjuster output shaft is generally
prevented.
[0009] Another object of an embodiment of the present invention is
to provide a headlamp adjuster which includes an overload clutch
mechanism which generally prevents over-travel of the adjuster
output shaft.
[0010] Briefly, and in accordance with one or more of the foregoing
objects, the present invention provides a headlamp adjuster which
includes an adjuster output shaft which is engageable with a
reflector of a headlamp assembly. The adjuster output shaft extends
from a housing, and the headlamp adjuster is configured such that
in an overload condition, the adjuster output shaft is prevented
from translating substantially axially, thereby reducing the risk
of damage resulting from over-travel of the adjustor output
shaft.
[0011] Although a few embodiments and alternatives are discussed
herein, it should be understood that modifications may be made
thereto while staying within the scope of the present
invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The organization and manner of the structure and function of
the invention, together with further objects and advantages
thereof, may be understood by reference to the following
description taken in connection with the accompanying drawings,
wherein:
[0013] FIG. 1 is a plan view of a typical headlamp assembly;
[0014] FIG. 2 is a side view, in partial cross-section, of a
headlamp adjuster which is in accordance with an embodiment of the
present invention;
[0015] FIG. 3 is a front, elevational view of the headlamp adjuster
shown in FIG. 2;
[0016] FIG. 4 is a perspective view of a bushing of the headlamp
adjuster shown in FIGS. 2 and 3;
[0017] FIG. 5 is a top, plan view of the bushing shown in FIG.
4;
[0018] FIG. 6 is a side, elevational view of the bushing shown in
FIG. 4;
[0019] FIG. 7 is a front, elevational view of the bushing shown in
FIGS. 4-6;
[0020] FIG. 8 is a cross-sectional view of the bushing shown in
FIGS. 4-7, taken along line 8-8 of FIG. 6;
[0021] FIG. 9 is a cross-sectional view of the bushing shown in
FIGS. 4-8, taken along line 9-9 of FIG. 7;
[0022] FIG. 10 is a side view, in partial cross-section, of a
headlamp adjuster which is in accordance with another embodiment of
the present invention;
[0023] FIG. 11 is a front, elevational view of the headlamp
adjuster shown in FIG. 10;
[0024] FIG. 12 is an exploded perspective view of a headlamp
adjuster which is in accordance with still yet another embodiment
of the present invention;
[0025] FIG. 13 is a side, elevational view, partially in section,
of an output gear, retaining member and clutch bushing
configuration which is used in connection with the headlamp
adjustor which is shown in FIG. 12;
[0026] FIG. 14 is a side, elevational view, partially in section,
of a rear portion of the headlamp adjuster shown in FIG. 12;
[0027] FIG. 15 is a rear, cross-sectional view of the headlamp
adjuster shown in FIG. 12, taken along line 15-15 of FIG. 14;
and
[0028] FIG. 16 is a top plan view of a headlamp adjuster which is
in accordance with still yet another embodiment of the present
invention.
DESCRIPTION OF EMBODIMENTS
[0029] While the present invention may be susceptible to embodiment
in different forms, there is shown in the drawings, and herein will
be described in detail, embodiments of the invention with the
understanding that the present description is to be considered an
exemplification of the principles of the invention and is not
intended to limit the invention to that as illustrated and
described herein.
[0030] Shown in the FIGURES are several different headlamp
adjusters which are in accordance with the present invention.
Specifically, FIGS. 2 and 3 illustrate a headlamp adjuster 100a
which is in accordance with a first embodiment of the present
invention, FIG. 10 and 11 illustrate a headlamp adjuster 100b which
is in accordance with a second embodiment of the present invention,
FIG. 12 illustrates a headlamp adjuster 100c which is in accordance
with a third embodiment of the present invention, and FIG. 16
illustrates a headlamp adjuster 100d which is in accordance with a
fourth embodiment of the present invention. Each headlamp adjuster
100a, 100b, 100c, 100d is configured for engagement with the
reflector of a headlamp assembly (see FIG. 1). As will be
described, each headlamp adjuster 100a, 100b, 100c includes an
overload clutch mechanism which generally prevents over-travel of
an adjuster output shaft 104a, 104b, 104c. Headlamp adjuster 100d
includes a collar stop which generally prevents over-travel of an
adjuster output shaft 104d, and may also include an overload clutch
mechanism.
[0031] The headlamp adjuster 100a which is shown in FIGS. 2 and 3
will be described first, and then the other three headlamp
adjusters 100b, 100c and 100d will be described. In the following
description, like reference numerals are used to identify like
parts, and different alphabetic suffixes (i.e., "a", "b", "c" and
"d") are used for each of the different embodiments. At times, a
detailed description of a part is omitted with the understanding
that one may review the description relating to like parts of the
other embodiments.
[0032] The headlamp adjuster 100a shown in FIGS. 2 and 3 includes
an adjuster output shaft 104a which is configured for engagement
with a reflector 24 of a headlamp assembly 12 (see FIG. 1).
Specifically, the adjuster output shaft 104a provides a threaded
shaft portion 106a and a ball portion 108a at one end for
engagement in a corresponding socket in a reflector 24 (see FIG. 1,
and above description, for example; see also FIG. 12 which shows an
adjuster output shaft 104c which is identical to adjuster output
shaft 104a).
[0033] The headlamp adjuster 100a also includes a housing 110a, and
the adjuster output shaft 104a extends from a shaft hole 112a in a
bushing 150a which is disposed in the housing 110a. The housing
110a is preferably mountable to the headlamp assembly or to some
other structure (see FIG. 1), such as a frame-like structure, which
is generally proximate the headlamp assembly. Preferably, the
headlamp adjuster 100a is "twist lock" mounted, such that the
headlamp adjuster 100a is mountable to a headlamp assembly 12 by
inserting an end 114a of the housing 110a into an aperture in a
housing 20 of the headlamp assembly 12 (see FIG. 1), and rotating
the housing 110a of the headlamp adjuster 100a relative to the
headlamp assembly 12 through a 120.degree. (one third) rotation. To
this end, the housing 110a preferably includes tabs 116a (shown in
FIG. 2, but omitted from FIG. 1) for engaging corresponding
structure in the aperture in the housing 20 of the headlamp
assembly 12.
[0034] Preferably, a sealing member (not shown in connection with
the headlamp adjuster 100a, but shown as part 118c in connection
with headlamp adjuster 100c illustrated in FIG. 12), such as an
elastomeric sealing ring formed of R7744 Silicone, is disposed
generally proximate the end 114a of the housing 110a. Preferably,
when the headlamp adjuster 100a is installed in the aperture in the
housing 20 of the headlamp assembly 12, the sealing member engages
the housing 20 of the headlamp assembly 12 to provide an axial
force between the housing 20 of the headlamp assembly 12 and the
housing 110a of the headlamp adjuster 100a and generally reduces
the amount of moisture which enters the headlamp assembly 12
through the aperture in the housing 20 of the headlamp assembly 12
and provides axial detent force for rotary lock. As will be
described more fully later herein, once the headlamp adjuster 100a
is properly mounted and engaged with the reflector 24, the headlamp
adjuster 100a can be manipulated to cause the adjuster output shaft
104a to translate relative to the housing 110a and effect an
adjustment to the position of the reflector 24.
[0035] The housing 110a may be formed of, for example, Zytel
70G13HS1L, and the adjuster output shaft 104a may be formed of, for
example, Delrin 570 or Zamac-3 (die casting) with a finish of
Zinc/yellow dichromate. Regardless, preferably the adjuster output
shaft 104a is easy to mold with plastic or die cast, and is
relatively low cost.
[0036] As shown in FIG. 2, preferably the adjuster output shaft
104a has a retaining member 120a, such as a retaining ring,
thereon. Preferably, the retaining member 120a is "snapped" onto
the adjuster output shaft 104a. While the end 122a of the adjuster
output shaft 104a opposite the ball portion 108a limits retraction
of the adjuster output shaft 104a into the housing 110a by nature
of contact between the end 122a of the adjuster output shaft 104a
and a rear internal stop wall 124a in the housing 110a, the
retaining member 120a disposed on the adjuster output shaft 104a
limits extension of the adjuster output shaft 104a from the housing
110a by nature of contact between the retaining member 120a and a
forward internal stop wall 126a in the housing 110a (this position
is shown in phantom in FIG. 2).
[0037] An output gear 130a is seated in the housing 110a, and the
output gear 130a generally coaxially receives the adjuster output
shaft 104a through a central bore 132a in the output gear 130a.
Preferably, the central bore 132a of the output gear 130a is tapped
such that it threadably engages the threaded portion 106a of the
adjuster output shaft 104a. As a result, rotation of the output
gear 130a in the housing 110a causes the adjuster output shaft 104a
to translate generally axially in the housing 100a when rotation is
prevented by the flats 162a, as seen in FIG. 3, or as will be
described more fully later herein, causes the adjuster output shaft
104a to rotate relative to the housing 100a.
[0038] An input gear 134a is driveably engaged with the output gear
130a such that rotation of the input gear 134a causes the output
gear 130a to rotate. Specifically, preferably external surfaces
136a and 138a of the input gear 134a and output gear 130a,
respectively, provide gear teeth with engage each other.
Preferably, a drive shaft portion 140a of the input gear 134a
extends from an aperture 142a in a cover 144a of the housing 110a,
and is configured to be engaged by a tool (not shown) to effect
rotation of the input gear 134a, and therefore rotation of the
output gear 130a in the housing 110a. As shown, an o-ring may be
provided between the cover 144a and the input gear 134 to provide a
seal therebetween.
[0039] Preferably the adjuster output shaft 104a not only extends
through the central bore 132a in the output gear 130a, but also
extends through a central bore 148a in a bushing 150a which is also
disposed in the housing 110a. A flange or tab 152a on the cover
144a engages a recess 154a on the exterior surface of the bushing
150a. This engagement generally prevents the bushing 150a from
moving generally axially within the housing 110a while allowing the
bushing 150a to rotate within the housing.
[0040] As shown in FIGS. 3 and 8, preferably the adjuster output
shaft 104a extends from an opening 156a in the end 158a of the
bushing 150a, and the opening 156a in the end 158a of the bushing
150a is shaped such that it generally corresponds to the
cross-sectional area of the adjuster output shaft 104a.
Specifically, preferably the opening 156a in the end 158a of the
bushing 150a is shaped such that it provides opposing walls 160a
which are configured to engage flat surfaces 162a (i.e.,
"bi-flats") on the adjuster output shaft 104a. The engagement
between the opposing walls 160a and the flat surfaces 162a of the
adjuster output shaft 104a provides that the adjuster output shaft
104a is generally prevented from rotating relative to the bushing
150a. Therefore, for the adjuster output shaft 104a to rotate
relative to the housing 110a, the bushing 150a must also be allowed
to rotate relative to the housing 110a.
[0041] Preferably, the bushing 150a is formed of plastic or some
other relatively flexible material. As shown in FIGS. 2-9, the
bushing 150a includes two diametrically-opposed flexible detents
166a which are preferably molded as part of the bushing 150a. As
shown in FIGS. 2 and 3, the bushing 150a is journalled within the
housing 110a, and the housing 110a contains a plurality of static
detents 170a (see FIG. 3) which are formed around the shaft hole
112a in the end 114a of the housing 110a. The flexible detents 166a
on the bushing 150a are engageable with and disengageable from the
static detents 170a on the housing 110a. When the flexible detents
166a of the bushing 150a are engaged with the static detents 170a
of the housing 110a, the bushing 150a is prevented from rotating
relative to the housing 110a. In contrast, when the flexible
detents 166a of the bushing are disengaged from the static detents
170a of the housing 110a, the bushing 150a can rotate relative to
the housing 110a. Therefore, because of the engagement between the
walls 160a at the opening 156a in the end 158a of the bushing 150a
and the flat surfaces 162a on the adjuster output shaft 104a, the
adjuster output shaft 104a cannot rotate in the housing 110a so
long as the flexible detents 166a of the bushing 150a are engaged
with the static detents 170a of the housing 110a. In contrast, the
adjuster output shaft 104a can rotate, along with the bushing 150a,
in the housing 110a when the flexible detents 166a of the bushing
110a are disengaged from the static detents 170a of the housing
110a.
[0042] In operation, the input gear 134a of the headlamp adjuster
100a is rotated (such as by using a tool on the drive shaft portion
140a) to change the position of the reflector. As the input gear
134a is rotated, the output gear 130a rotates and causes the
adjuster output shaft 104a to translate axially in the housing
110a, thereby changing the position of the reflector. So long as
the end 122a of the adjuster output shaft 104a does not move into
engagement with the rear stop wall 124a in the housing 110a, and
the retaining member 120a disposed on the adjuster output shaft
104a does not move into engagement with the forward stop wall 126a
in the housing 100a, the flexible detents 166a of the bushing 150a
remain engaged with the static detents 170a on the housing 110a,
and the bushing 150a and adjuster output shaft 104a are prevented
from rotating relative to the housing 110a. Hence, so long as the
end 122a of the adjuster output shaft 104a does not move into
engagement with the rear stop wall 124a in the housing 110a, and
the retaining member 120a disposed on the adjuster output shaft
104a does not move into engagement with the forward stop wall 126a
in the housing 110a, rotation of the input gear 134a causes the
adjuster output shaft 104a to translate axially in the housing
110a, as opposed to rotate in the housing 110a.
[0043] Once the input gear 134a has been rotated enough such that
either the end 122a of the adjuster output shaft 104a moves into
engagement with the rear stop wall 124a in the housing 110a or the
retaining member 120a disposed on the adjuster output shaft 104a
moves into engagement with the forward stop wall 126a in the
housing 110a, the flexible detents 166a on the bushing 150a
disengage from the static detents 170a on the housing 110a and
continued rotation of the input gear 134a in the same direction
causes the adjuster output shaft 104a (and bushing 150a) to rotate
in the housing 110a, as opposed to continue to translate axially,
further moving the reflector. Hence, over-travel of the adjuster
output shaft 104a in either direction is prevented by a clutch
mechanism which is provided by the detents 166a on the bushing 150a
and the static detents 170a of the housing 110a.
[0044] Preferably, the range of axial travel of the adjuster output
shaft 104a is limited to six rotations of the input gear 134a, and
during this range of travel, the adjuster output shaft 104a travels
about 12 mm. When the input gear 134a is rotated and the retaining
member 120a on the adjuster output shaft 104a moves into engagement
with the forward stop wall 126a in the housing 110a, the tension in
the adjuster output shaft 104a increases due to the output gear
130a being constrained in the housing, bearing on surface 176a.
This axial tension effectively couples the output gear 130a to the
adjuster output shaft 104a by means of friction at the thread
interfaces between the output gear 130a and the adjuster output
shaft 104a. When this occurs, the adjuster output shaft 104a tends
to rotate the bushing 150a, thereby causing the flexible detents
166a of the bushing 150a to disengage from the static detents 170a
on the housing 110a. Thereafter, as the input gear 134a continues
to be rotated in the same direction, the bushing 150a is free to
rotate in the housing 110a, and the adjuster output shaft 104a,
instead of continuing to translate, rotates along with the bushing
150a. Therefore, the adjuster output shaft 104a does not
over-travel in the extending direction (i.e., toward the reflector)
as the input gear 134a continues to be rotated in the same
direction.
[0045] Turning the input gear 134a in the opposite direction
releases the axial tension between the adjuster output shaft 104a
and the output gear 130a. Hence, the friction coupling reduces and
the torque on the bushing 150a reduces. When this occurs, the
flexible detents 166a on the bushing 150a re-engage the static
detents 170a on the housing 110a and the bushing 150a is prevented
from continuing to rotate relative to the housing 110a. When the
bushing 150a stops rotating, the adjuster output shaft 104a also
stops rotating, and instead begins to translate axially away from
the stop interference.
[0046] As the input gear 134a continues to be rotated in the same
direction such that the adjuster output shaft 104a sufficiently
axially translates causing the end 122a of the adjuster output
shaft 104a to move into contact with the rear stop wall 124a in the
housing 110a, the tension in the adjuster output shaft 104a
increases due to the output gear 130a being constrained in the
housing 110a, bearing on surface 178a. This axial tension
effectively couples the output gear 130a to the adjuster output
shaft 104a by means of friction at the thread interfaces between
the output gear 130a and the adjuster output shaft 104a. When this
occurs, the adjuster output shaft 104a tends to rotate the bushing
150a, thereby causing the flexible detents 166a of the bushing 150a
to disengage from the static detents 170a on the housing 110a.
Thereafter, as the input gear 134a continues to be rotated in the
same direction, the bushing 150a is free to rotate in the housing
110a, and the adjuster output shaft 104a, instead of continuing to
translate, rotates along with the bushing 150a. Therefore, the
adjuster output shaft 104a does not over-travel in the retracting
direction (i.e., away from the reflector) as the input gear 134a
continues to be rotated in the same direction.
[0047] Turning the input gear 134a in the opposite direction
releases the axial tension between the adjuster output shaft 104a
and the output gear 130a. Hence, the friction coupling reduces and
the torque on the bushing 150a reduces. When this occurs, the
flexible detents 166a on the bushing 150a re-engage the static
detents 170a on the housing 110a and the bushing 150a is prevented
from continuing to rotate relative to the housing 110a. When the
bushing 150a stops rotating, the adjuster output shaft 104a also
stops rotating, and instead begins to translate axially away from
the stop interference.
[0048] Hence, over-travel of the adjuster output shaft 104a in
either direction is prevented by a clutch mechanism which is
provided by the detents 166a on the bushing 150a and the static
detents 170a of the housing 110a. The detent force is important to
the clutch mechanism function. One having ordinary skill in the art
would recognize that a higher initial coupling (frictional) between
the adjuster output shaft 104a and the output gear 130a would allow
for more margin to meet clutch slip torque which is determined by
the detenting.
[0049] The headlamp adjuster 100b shown in FIGS. 10 and 11 is
similar to the headlamp adjuster 100a shown in FIGS. 2 and 3.
Therefore, similar reference numerals are used to identify similar
parts, and the alphabetic suffix "b" is used. At times, a detailed
description of a part is omitted with the understanding that one
may review the description relating to a corresponding part of one
of the other embodiments.
[0050] The headlamp adjuster 100b shown in FIGS. 10 and 11 includes
an adjuster output shaft 104b having a ball portion 108b, a
threaded portion 106b, and flat surface portions 162b (i.e.,
"bi-flats"), and the adjuster output shaft 104b has a retaining
member 120b thereon. The headlamp adjuster 10b, like headlamp
adjuster 100a, includes a housing 110b, a cover 144b and a sealing
member 143b. As shown in FIG. 11 (but omitted from FIG. 10), like
the housing of headlamp adjuster 100a, preferably the housing 110b
of headlamp adjuster 100b has tabs 116b thereon which engage
corresponding structure in the aperture in the housing 20 of the
headlamp assembly 12 (see FIG. 1), thereby providing that the
headlamp adjuster 100b is "twist lock" mountable. The housing 100b
includes a shaft hole 112b from which the adjuster output shaft
104b extends. As shown in FIG. 11, the shaft hole 112b is shaped
such that it generally corresponds to the cross-sectional area of
the adjuster output shaft 104b. Specifically, preferably the shaft
hole 112b provides opposing walls 160b which are configured to
engage the flat surfaces 162b (i.e., the "bi-flats") on the
adjuster output shaft 104b. The engagement between the opposing
walls 160b and the flat surfaces 162b of the adjuster output shaft
104b provides that the adjuster output shaft 104b is generally
prevented from rotating relative to the housing 110b.
[0051] As shown in FIG. 10, the headlamp adjuster 100b, like
headlamp adjuster 100a, includes an input gear 134b and an output
gear 130b. However, unlike headlamp adjuster 100a, the output gear
130b of headlamp adjuster 100b is not threadably engaged with the
adjuster output shaft 104b. Instead, a clutch bushing 150b is
threadably engaged with the adjuster output shaft 104b, and the
output gear 130b has a free running fit on the external surface of
the clutch bushing 150b. The clutch bushing 150b includes a
shoulder 180b, and a friction coupling member 182b, such as an
o-ring formed of nitrile, which is compressed between the output
gear 130b and the shoulder 180b of the clutch bushing 150b. In
addition to providing a friction coupling, the elastomeric nature
of the o-ring also provides a biasing action. As shown in FIG. 10,
the clutch bushing 150b, elastomeric member 182b, and output gear
130b are disposed in a seat 184b in the housing 110b. The
compressed elastomeric member 182b provides a friction coupling
between the threaded clutch bushing 150b and the output gear 130b,
which can slip under an overload condition.
[0052] In operation, the input gear 134b of the headlamp adjuster
100b is rotated (such as by using a tool) to change the position of
the reflector. As the input gear 134b is rotated, the output gear
130b rotates and, because of the friction coupling between the
output gear 130b and clutch bushing 150b, provided by the
compressed friction coupling member 182b, the clutch bushing 150b
also rotates. Rotation of the clutch bushing 150b causes the
adjuster output shaft 104b to translate due to the threadable
engagement between the output gear 130b and adjuster output shaft
104b and the engagement of the adjuster output shaft 104b with the
opposing walls 160b at the shaft hole 112b in the housing 110b (see
FIG. 11). As the adjuster output shaft 104b translates axially, the
position of the reflector changes. So long as the end 112b of the
adjuster output shaft 104b does not move into engagement with a
rear stop wall 124b in the housing 110b, and the retaining member
120b disposed on the adjuster output shaft 104b does not move into
engagement with a forward stop wall 126b in the housing 110b,
rotation of the input gear 134b causes the clutch bushing 150b to
rotate and the adjuster output shaft 104b to translate axially.
[0053] Once the input gear 134b has been rotated enough such that
either the end 122b of the adjuster output shaft 104b moves into
engagement with the rear stop wall 124b in the housing 110b or the
retaining member 120b disposed on the adjuster output shaft 104b
moves into engagement with the forward stop wall 126b in the
housing 110b, the output gear 130b will slip relative to the clutch
bushing 150b and the clutch bushing 150b will not rotate. That is
to say, an overload condition will exist, such that continued
attempt to rotate the input gear 134b, will overcome the friction
coupling provided by the elastomeric member 182b and output gear
130b will in effect "slip" relative to the clutch bushing 150b.
Thus, the input gear 134b and the output gear 130b can rotate
without movement of the output shaft 104b. Hence, the adjuster
output shaft 104b does not continue to translate axially. The
clutch action between the output gear 130b and the clutch bushing
150b when the end 122b of the adjuster output shaft 104b moves into
engagement with the rear stop wall 124b in the housing 110b or the
retaining member 120b disposed on the adjuster output shaft 104b
moves into engagement with the forward stop wall 126b in the
housing 110b provides that over-travel of the adjuster output shaft
104b in either direction is prevented.
[0054] Preferably, the range of axial travel of the adjuster output
shaft 104b is limited to six rotations of the input gear 134b, and
during this range of travel, the adjuster output shaft 104b travels
about 12 mm. When the input gear 134b is rotated and the retaining
member 120b on the adjuster output shaft 104b moves into engagement
with the forward stop wall 126b in the housing 110b, the tension in
the adjuster output shaft 104b increases due to the output gear
130b being constrained in the housing, bearing on surface 176b.
This axial tension effectively couples the clutch bushing 150b to
the adjuster output shaft 104b by means of friction at the thread
interfaces between the clutch bushing 150b and the adjuster output
shaft 104b. When this occurs, further rotation of the input gear
134b causes the output gear 130b to slip relative to the clutch
bushing 150b, and the adjuster output shaft 104b no longer
translates axially. Therefore, the adjuster output shaft 104b does
not over-travel in the extending direction (i.e., toward the
reflector) as the input gear 134 continues to be rotated in the
same direction.
[0055] Turning the input gear 134b in the opposite direction
releases the axial tension between the adjuster output shaft 104b
and the clutch bushing 150b. Hence, the friction coupling reduces,
and the clutch bushing 150b begins to move along with the output
gear 130b, and the adjuster output shaft 104b begins to translate
axially.
[0056] As the input gear 134b continues to be rotated in the same
direction such that the adjuster output shaft 104b sufficiently
axially translates causing the end 122b of the adjuster output
shaft 104b to move into contact with the rear stop wall 124b in the
housing 110b, the tension in the adjuster output shaft 104b
increases due to the clutch bushing 150b being constrained in the
housing 110b, bearing on surface 178b. This axial tension
effectively couples the clutch bushing to the adjuster output shaft
104b by means of friction at the thread interfaces between the
clutch bushing 150b and the adjuster output shaft 104b. When this
occurs, further rotation of the input gear 134b causes the output
gear 130b to slip relative to the clutch bushing 150b, and the
adjuster output shaft 104b no longer translates axially. Therefore,
the adjuster output shaft 104b does not over-travel in the
retracting direction (i.e., away from the reflector) as the input
gear 134b continues to be rotated in the same direction.
[0057] Turning the input gear 134b in the opposite direction
releases the axial tension between the adjuster output shaft 104b
and the clutch bushing 150b. Hence, the friction coupling reduces,
and the clutch bushing 150b begins to move again along with the
output gear 130b, and the adjuster output shaft 104b begins to
translate axially.
[0058] Hence, over-travel of the adjuster output shaft 104b in
either direction is prevented by a clutch mechanism which is
provided by the interaction between the output gear 130b, the
elastomeric member 182b and the clutch bushing 150b.
[0059] The headlamp adjuster 100c shown in FIG. 12 is similar to
the headlamp adjusters 100a and 100b shown in FIGS. 2-3 and 10-11,
respectively. Therefore, similar reference numerals are used to
identify similar parts, and the alphabetic suffix "c" is used. At
times, a detailed description of a part is omitted with the
understanding that one may review the description relating to a
corresponding part of one of the other embodiments.
[0060] The headlamp adjuster 100c shown in FIG. 12 includes an
adjuster output shaft 104c having a ball portion 108c, a threaded
portion 106c, and flat surface portions 162c (i.e., "bi-flats"),
and the adjuster output shaft 104c has a retaining member 120c
thereon. Preferably, the retaining member 120c is crimped onto the
adjuster output shaft 104c (represented with force arrows "F" in
FIG. 15) so that the retaining member 120c does not have a tendency
to rotate relative to the adjuster output shaft 104c. The headlamp
adjuster 100c, like headlamp adjusters 100a and 100b, includes a
housing 110c, a cover 144c and a sealing member 143c, and
preferably includes a sealing member 118c proximate the front 114c
of the housing 110c for sealing against the housing 20 of the
headlamp assembly 12 (see FIG. 1). As shown, preferably the housing
110c of headlamp adjuster 100c has tabs 116c thereon which engage
corresponding structure in the aperture in the housing 20 of the
headlamp assembly 12, thereby providing that the headlamp adjuster
100c is "twist lock" mountable. The housing 110c includes a shaft
hole 112c from which the adjuster output shaft 104c extends. As
shown in FIGS. 12 and 14, a tower 190c is attached to the rear of
the housing 110c, and the end 122c of the adjuster output shaft
104c extends into the tower 190c.
[0061] As shown in FIG. 12, the headlamp adjuster 100c, like
headlamp adjuster 100b, includes an input gear 134c, an output gear
130c, a clutch bushing 150c and a friction coupling member 182c,
such as an elastomeric washer. However, unlike the headlamp
adjuster 100b shown in FIGS. 10 and 11, the headlamp adjuster shown
in FIG. 12 includes a clutch mechanism which has an additional
member in the form of a friction washer 196c which is disposed
intermediate the output gear 130c and the clutch bushing 150c. The
configuration of the output gear 130c, friction coupling member
182c, friction washer 196c and clutch bushing 150c is shown in FIG.
13. As shown, the output gear 130c provides a seat 198c for
receiving the elastomeric friction coupling member 182c, and the
friction washer 196c is provided between the elastomeric member
182c and the clutch bushing 150c. Preferably, the output gear 130c
has a free running fit on the external surface of the extension on
the clutch bushing 150c, and the compressed friction coupling
member 182c provides a friction coupling between the clutch bushing
150c and the output gear 130c. The biasing action provided by the
elastomeric member 182c, forces the friction washer 196c into
engagement with clutch bushing 150c. Preferably, the friction
washer 196c is formed of a flexible non-asbestos molded material
with medium to high friction, good stability and good wear
characteristics. Specifically, the friction washer 196c may be
obtained from Great Lakes Friction Products, Inc. 8601 North 43rd
Street, Milwaukee, Wis. 53209 pursuant to Engineering Product Data
Sheet GL134-142. The friction washer 196c effectively acts as a
barrier to adhesion between the elastomeric member 182c and the
clutch bushing 150c. In other words, the friction washer 196c will
have a tendency to slip relative to the clutch bushing 150c before
the elastomeric member 182c has a tendency to slip between the
friction washer 196c and the output gear 130c. As a result, a more
constant breakaway torque (between the clutch bushing 150c and
output gear 130c) is maintained over time compared to the
embodiment wherein the friction washer 196c is not utilized (i.e.,
as shown in FIG. 10). It should be noted however, that while it is
preferred that the clutch action take place between the friction
washer 196c and clutch bushing 150c, slippage may also occur
between member 182c and the friction washer 196c.
[0062] As shown in FIG. 12, a nut 200c is provided in a seat 202c
in the housing 110c. Preferably, unlike with headlamp adjuster
100b, the clutch bushing 150c is not threadably engaged with the
adjuster output shaft 104c. Instead, the adjuster output shaft 104c
is threadably engaged with the nut 200c which is seated in the
housing 110c, as shown in FIG. 14, and the clutch bushing 150c
provides opposing walls 160c (see FIG. 12) which engage the flat
portions 162c of the adjuster output shaft 104c. Hence, the
adjuster output shaft 104c cannot rotate relative to the clutch
bushing 150c, and rotation of the clutch bushing 150c causes the
adjuster output shaft 104c to also rotate, however the shaft 104c
is free to translate relative to the bushing 150c. The threadable
engagement between the nut 200c which is seated in the housing 100c
(see FIG. 14) and the adjuster output shaft 104c causes the
adjuster output shaft 104c to translate axially when the adjuster
output shaft 104c rotates. Therefore, rotation of the clutch
bushing 150c causes the adjuster output shaft 104c to translate
axially, thereby changing the position of the reflector which is
engaged with the adjuster output shaft 104c (see FIG. 1).
[0063] In operation, the input gear 134c of the headlamp adjuster
100c is rotated (such as by using a tool) to change the position of
the reflector. As the input gear 134c is rotated, the output gear
130c rotates and, because of the friction coupling between the
output gear 130c, elastomeric member 182c, friction washer 196c and
clutch bushing 150c, the clutch bushing 150c also rotates. Rotation
of the overall clutch mechanism, including bushing 150c causes the
adjuster output shaft 104c to translate due to the threadable
engagement between the adjuster output shaft 104c and the nut 200c
which is seated in the housing 110c (see FIGS. 12 and 14). As the
adjuster output shaft 104c translates axially, the position of the
reflector changes. So long as the end 122c of the adjuster output
shaft 104c does not move into engagement with a rear stop wall 124c
in the tower 190c, and the retaining member 120c disposed on the
adjuster output shaft 104c (see FIGS. 12 and 14) does not move into
engagement with a forward stop wall 126c on the housing 110c,
rotation of the input gear 134c causes the clutch bushing 150c to
rotate and the adjuster output shaft 104c to translate axially.
[0064] Once the input gear 134c has been rotated enough such that
either the end 122c of the adjuster output shaft 104c moves into
engagement with the rear stop wall 124c in the tower 190c or the
retaining member 120c disposed on the adjuster output shaft 104c
moves into engagement with the forward stop wall 126c on the
housing 110c, the output gear 130c, elastomeric member 182c and
friction washer 196c will slip relative to the clutch bushing 150c
and the clutch bushing 150c will not rotate. That is to say, an
overload condition will exist, such that continued attempt to
rotate the input gear 134c, will overcome the friction coupling
provided by the elastomeric member 182c and output gear 130c will
in effect "slip" relative to the clutch bushing 150c. Thus, the
input gear 134c and the output gear 130c can rotate without
movement of the output shaft 104c. Hence, the adjuster output shaft
104c does not continue to translate axially. The clutch action
between the output gear 130c and the clutch bushing 150c when the
end 122c of the adjuster output shaft 104c moves into engagement
with the rear stop wall 124c in the tower l90c or the retaining
member 120c disposed on the adjuster output shaft 104c moves into
engagement with the forward stop wall 126c on the housing 110c
provides that over-travel of the adjuster output shaft 104c in
either direction is prevented.
[0065] Preferably, the range of axial travel of the adjuster output
shaft 104c is limited to six rotations of the input gear 134c, and
during this range of travel, the adjuster output shaft 104c travels
about 12 mm. When the input gear 134c is rotated and the retaining
member 120c on the adjuster output shaft 104c moves into engagement
with the forward stop wall 126c on the housing 110c, the tension in
the adjuster output shaft 104c increases due to the output gear
130c being constrained in the housing 110c. This axial tension
effectively couples the clutch bushing 150c to the adjuster output
shaft 104c by means of friction at the interface therebetween. When
this occurs, further rotation of the input gear 134c causes the
output gear 130c, elastomeric member 182c and friction washer 196c
to slip relative to the clutch bushing 150c, and the adjuster
output shaft 104c no longer translates axially. Therefore, the
adjuster output shaft 104c does not over-travel in the extending
direction (i.e., toward the reflector) as the input gear 134c
continues to be rotated in the same direction.
[0066] Turning the input gear 134c in the opposite direction
releases the axial tension between the adjuster output shaft 104c
and the clutch bushing 150c. Hence, the friction coupling reduces,
and the clutch bushing 150c begins to move along with the output
gear 130c, and the adjuster output shaft 104c begins to translate
axially.
[0067] As the input gear 134c continues to be rotated in the same
direction such that the adjuster output shaft 104c sufficiently
axially translates causing the end 122c of the adjuster output
shaft 104c to move into contact with the rear stop wall 124c in the
tower 190c, the tension in the adjuster output shaft 104c increases
due to the clutch bushing 150c being constrained in the housing
110c. This axial tension effectively couples the clutch bushing
150c to the adjuster output shaft 104c by means of friction at the
interface therebetween. When this occurs, further rotation of the
input gear 134c causes the output gear 130c, elastomeric member
182c and friction washer 196c to slip relative to the clutch
bushing 150c, and the adjuster output shaft 104c no longer
translates axially. Therefore, the adjuster output shaft 104c does
not over-travel in the retracting direction (i.e., away from the
reflector) as the input gear 134c continues to be rotated in the
same direction.
[0068] Turning the input gear 134c in the opposite direction
releases the axial tension between the adjuster output shaft 104c
and the clutch bushing 150c. Hence, the friction coupling reduces,
and the clutch bushing 150c begins to move again along with the
output gear 130c, and the adjuster output shaft 104c begins to
translate axially.
[0069] Hence, over-travel of the adjuster output shaft 104c in
either direction is prevented by a clutch mechanism which is
provided by the interaction between the output gear 130c, the
elastomeric member 182c, the friction washer 196c and the clutch
bushing 150c.
[0070] The headlamp adjuster 100d shown in FIG. 16 is very similar
to the headlamp adjuster 100c shown in FIG. 12. In fact, the only
difference is that the headlamp adjuster 100d shown in FIG. 16
includes a collar stop 240d on the adjuster output shaft 104d,
proximate the ball portion 108d. Preferably, the collar stop 240d
is generally tubular with an inside diameter greater than the
outside diameter of the threaded portion 106d of the adjuster
output shaft 104d. Preferably, the collar stop 240d is disposed on
the adjuster output shaft 104d such that the collar stop 240d
generally contacts the ball portion 108d. Ideally, the collar stop
240d is a relatively low cost part, and may be made, for example,
by cutting tubing to a pre-determined length ("L" in FIG. 16). In
such case, the length (L) may be variable depending on the desired
travel of the adjuster output shaft 104d (i.e. depending on how far
one wants the adjuster output shaft 104d to be retractable).
[0071] While in the headlamp adjuster 100c shown in FIG. 12 the
rear wall 124c of the tower 190c limits travel of the adjuster
output shaft 104c in the retraction direction, in the headlamp
adjuster 100d shown in FIG. 16 the collar stop 240d limits travel
of the adjuster output shaft 104d in the retraction direction.
Specifically, when the adjuster output shaft 104d is retracted to
the fullest extent, the collar stop 240d engages surface 242d of
the housing 110d, thereby generally preventing the adjuster output
shaft 104d from being retracted any further. By providing a collar
stop 240d to limit travel in the retraction direction, rather than
providing that the end 122d of the adjuster output shaft 104d bears
against the internal wall 124d of the tower 190d, there is no risk
of stressing, for example, a possible weld joint 244d between the
housing 110d and tower 190d.
[0072] With regard to the other direction, i.e. extension of the
adjuster output shaft 104d, the headlamp adjuster 100d shown in
FIG. 16, like the headlamp adjuster 100c shown in FIG. 12, includes
a retaining member 120d which is crimped or otherwise engaged with
the adjuster output shaft 104d, proximate the end 122d of the
adjuster output shaft 104d. When the adjuster output shaft 104d is
extended to the fullest extent, the retaining member 120d which is
disposed on the adjuster output shaft 104d engages the forward stop
wall 126d on the housing 110d, thereby generally preventing the
adjuster output shaft 104d from being extended any further. A
qualified thread coating may be applied to the ball portion 108d of
the adjuster output shaft 104d and this would restrict movement of
the collar stop 240d when the adjuster output shaft 104d is
extended and the collar stop 240d would otherwise be free to move
(i.e. along the threaded portion 106d of the adjuster output shaft
104d, generally away from the ball portion 108d of the adjuster
output shaft 104d). As an alternative to the tubular form of the
collar stop 240d, the collar stop 240d may be in the form of a
split or snap ring that is applied to the shaft 104d, generally
adjacent the head 108d.
[0073] While the headlamp adjuster 100d shown in FIG. 16 is shown
as being generally identical (other than including a collar stop
240d) to the headlamp adjuster 100c which is shown in FIG. 12,
including having a similar clutch assembly/mechanism 250d, it
should be understood that the headlamp adjuster 100d may not
include a clutch mechanism at all, and may merely include means to
prevent over-retraction and extension of the adjuster output shaft
104d.
[0074] Each headlamp adjuster 100a, 100b, 100c and 100d is
configured to generally prevent over-travel of the adjuster output
shaft 104a, 104b, 104c in both the extending and retracting
directions. Hence, the reflector and the headlamp adjusters 100a,
100b, 100c do not tend to become damaged as a result of
over-rotation of the input gear 134a, 134b, 134c, 134d.
[0075] While embodiments of the present invention are shown and
described, it is envisioned that those skilled in the art may
devise various modifications without departing from the spirit and
scope of the foregoing description.
* * * * *