Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
:
1074843
..... , . . . . . . . , . . . ~ . - . ` , R~CK~ROUND OF I~E INVE~TIO~
Node~n automot~ive headlamps ~equire precise positioning:
-~ ; o the filamen~ with respect to ~he~ reflPctor. ~In additi~n,
they require precise positioning o~ a Eilament shield o~ward,~
:aft~and~to the sides of the filament to prevent the forwards;~
aft and~side~ays pro3ection:o~ light rays~directll~ from ~he~
ilament. ~In-particular, the~:embodiment described:prev~nt
the uti~ization of light~rays from approximately the lower
half;af the:fil~ment.
: : : : : , ~ :
7~43
The prior art fails to teach a method of mounting :.
both filament and filament shield in a precise manner .
while requiring only normal handling of the parts during
assembly.
SUMMARY O~ THE INVENTION
The instant invention teaches a headlamp filament and
shield, and the method of assembling same which enables ~;
precise positioning of both filament and shield within the
reflector of the headlamp envelope. :
The filament and its shield are first welded together
into a rigid subassembly. The filament/shield subassembly
is welded as a unit to support and power-source pins within `~
the headlamp. A portion of the filament shield, previously : .
producing an electrical short circuit across the filament .:.
is cut away after the subassembly is securely aligned and . .:
welded in place. . .
: ~riefly described the present invention teaches a ~ .
method of assembling the filament and metallic shield in .~ -.
an automotive type headlamp comprising preassembling the-
filament and filament shield into a rigid subassembly ~ith . :
the filament being welded at each of its two mounting legs .. ..
to the filament shield whereby an electrical short circuit
: is formed through the metallic filament shield between the
ends of the filamentt then welding the subassembly to support
~pins in a reflector of a headlamp~ then support pins also
: :being adapted to providing electrical connection to the
i ~
filament, and then cutting away the connecting metal between
the locatlon on the filament shield where one end of thq :
filament iswelded and the remainder of the filament shield ~-:
:; 30 ~wher.ebythe electrical short circuit of the filament previously
:: . . .
. ~ - 2 -
sam/:.~
4~343
existing through the body of the filament shield is removed.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 shows a schematic view of a headlamp containing
the filament shield and lamp filament of the present
invention.
Fig. 2 shows the required illumination and blocking of
the headlamp reflector.
Fig. 3 shows a top view of the headlamp shield.
Fig. 4 shows the lamp filament.
Fig. 5 shows the filament shield and filament in a
unitary subassembly.
- . ~.
.
. .
` ~ ' '.: " .
.~ .
:' ;' ~: '.
' .'~
: : , .. :
~ `
.
: ..
~ ~ '
: ~ .
~; : .':` `~
~:
~' ~
- 2a -
sam/ ~
: ' , .~ ',~:
., ... ...:
~L~7~843
Fig. 6 shows a ~ross-sectional view of the ~ilament
shield and filament taken along 6-6 oE Fig. 5.
Fig. 7 shows the shield/~ilament subassembly mounted
in a headlamp reflector.
Fig. 8 shows ~he ilamen~ and shield installed and
trimmed in its final assembled condition.
~ ETAIlED DE:SCRIPTIO~ OF_THE PREEERRED E:M~ODIMENT
. Fig. 1 sho~s the arrangement o the low-beam lamp
filament in a European-type headlamp shown generaLly at 10.
A cy~indrical ~piral lamp filament 12 is located with the
,. .. . . . .
axis o~ the cyl~.ndricaL lamp filament ~2 approximately on
,
the axis o the paraboloid lamp re1ector 14. The specifi-
cations or such lamps require that the low-beam filame~
'12 be prevented from illuminating certain~portions:of ~he
læ~p re~lector 14. In addition, the specifications requir~
. that axial and n~ar axial forward xadiation directly rom
.
the ~lament 12 be blocked. This control of directional ~ _ :
illumLnation is~ accompli9hed asing a shield 15 whicb pa~tLal b
: enclo~és the ~Llament 12
20 ~ ; A~ aft shield 16, interposed betw~en the ilament 1
~nd the re1ector 14 blocks di~ect xearward illumination o :~
the reflector 14~by the filam~nt 12~ The shape of this
blockag~ will~ be described~;~in later paragraphs. A forward
:shield lS,`~larger than the aft shield~ is located forward
. .: , . - : : ~
: o$ ~the ~ilamen~ 12. The orward shield 18 blocks forward
: radiation directly ~rom the filament 12~ h lower shield 20
~ ~ :
bio~ks illumination o the bottom and side5 of the ~e1ector
- 3 - :
: ' ~
.
8~
in a predetermined pattern. The remaining illumination Erom
the ~ilament 12, a~ter xe1ec~ion from the reflector 14, is
direc~ed below the axis of the lamp reflector 14 as required
by the speci~ications of this type of lamp 10.
Fig. 2 shows ~he desired illumination pattern of the
reflector 14. The stippled portion 22 describes ~he area
required to be blocked ~rom illumination by the filament.
- . .
The plain portion 24 describes the illuminated area~ In addi-
.
tio~ to blockage o~ the lower 165 degrees of the ~e~lector
- 1~ 14, the ~locked portion 22 also includes a semicircular
central blocked portion 26 concèntric wit~ the paraboloid
.
axis.
A t~p view ~of the shield 15 is shown in Fig. 3. The
- : forv~ard d~rection is do~nward in Fig. 3. ~he shield 15 :-
contains a concavity 28 within which the ~ilæment 12 is
~- ~uspended. An approximately rectangular mounting plate 30
extend~ outw~rd, toward the right in the drawing, rom the
.- . , . - : .
concavity 28. Two stiffening corru~ations 32, 32a in ~he
mounting.plate 30 extend outward ~rom the concavity 28 to
-, ' `:
~, 20 ~ ~ ~ mou~ting flange 34. .
A flat flange 3~ is comlected to the le~t side o~ the
shield 15 in the~drawing. A depression 38 is pruvided near
the forward end o~ the flat ~lange 36, to provide clear~nce
fdr one of the filament 12 legs as will be described later.
: A bump 40 is positioned in the rear of the flat flange 36
to provide an electrical and mechanical connection point
for ~he filamen~ 12.
,
.:
.
A forward shield 42 prevents the forward projection
of light from the filament 12.
A J-shaped projection 44 projects fxom adjacent the
forward end of the flat flange 36. The J-shaped projection
44 has a long leg 46, a short leg 48, and a base 50.
The filament 12 is shown in Fig. 4. The filament 12
is of the type known as a Sleeper-Hartley filament. The
Sleeper-Hartley filament consists of a cylindrical coil of
filament wire 52 ana two parallel legs 54,56. The ~ilament
legs 54,56 in this embodiment of the present invention are ;~
of unequal length. The long filament leg 54 is longer than
the short filament leg 56. The cylindrical coil of filament
wire 52 contains an integral number of turns plus 1/2 turn.
Thus the two legs 54, 56 emerge from the coil 52 parallel to
each other o~ the same side of the axis of the coil 52 but
separated by the diameter of the coil. As shown in the figure,
the long filament leg 54 projects toward the left from the
bottom of the coil 52 whereas the short filament leg 56 pro-
jects toward the left from the top of the coil 52.
Fig. 5 shows a preassembled su~assembly in which the
filament 12 is preassembled into the filament shield 15.
The long filament leg 54 passes through the depression 38
without making mechanical or electrical contact at this
point and makes contact with the short leg 48 of the J-
shaped projection 44. The long filament leg 54 ls welded
to the short leg 48 of the J-shaped projection 44 at their
,~ :
:' ..' :
~
.~:: ,:
:~
: ~ ' ' .:
jrr/~ ~
~7D~8~k3
point of contact 58. The short filament leg 56 passes over
the flat 1ange 36 and makes contactlwith the bump 40. The
short ~ilament leg 56 and the bump 40 are welded at their
point of contact 60.
When preassembled in the fashion described in preceding
paragraphs, the filament shield 15 and filament 12 form a
rugged subassembly adap~ed tu handlln~ in further manu-
ac uring processes without losing the required spatLal
: relationships between them. ~ote that at ~his stage o
: preassembly, the filament shLeld provide9 a dead electrical
short across. the legs 54, 56 of the ~ilamen~ 12.
,, , ~ . .
~ he cross-sectio~al vlew in F~g. 6 ~ake~ along ~ine 6-6
in Fig. 5 illustrate9 the relative posLtioning of the.elements
~ ~ of the s~bassembly. Mounting flange 34 at the outer end of
: the mounting plate 30 i8 seen to contain an S-shaped curve~
containing an in~er concave angle 62 and ~n outer concave
~ angle 6-4. The outer concave angle 64 ls used for precise ~
:` pos~tionin~ of ~he ~ubassem~ly within the headlamp ref~ector -
. . ,. : ~
as w~ll be described later~ The stiffening corrugatio~ 32a
. . . ~ . .
20:~ ; and 32 (beh~nd 32a) contribute rigidity;to t~e mount~ng plate ~:
30 in order that the assembly may resist tion under normal
road use. :~ ~
The long fLlament leg 54 Ls shown, at the end of the
fLlament 12 nearest the viewer, passin~ through the depres- : :
sLon 38 and making contact with t~e short leg of the ~ 48. ~ :~
`::; The lon~ leg of the J 46 is b~nt at the point it joLns the
: fia~ fl~nge 36 in order to translate the short :Leg o the
.
~74~343
J 46 to the level required to make collinear contact with
the emerging long ~ilament leg 54.
The short ilament leg 56, at the end o:E the f ilament
12 farthes~ from the viewer, makes contact with the bump ~0
The aft shield 16 is shown to contain an upper semi-
circular part 66 and a lower part 68. This shape o the
shield 16 provide~ the correct blocking pattern to provide
.
the speciied pat~ern ~ r6flector illumination as previously
shown ~n Fig. 2. :
~ The insta11ation o~ the subassembly in the head1amp
begins wlth the ærangement shown in FigD 7. A ~ir9t mount~ng
pin 70, passirlg sealably through the Iamp re:Elector 14, ~ -
pxovides both mechanlcal support and electrical supply ~o ~ ;
. . . i .
the subassembly. A second mounting pin 72 ~rovides aII :
: ~ ~ initial alig~nt bearing and subsequent elec~rical supply ;~
to the subassembly. The outer concave angle 64, ~unning ~he ~ :
entire le~gth-of the mounting 1~nge 34 ls itted against ~ :
the ~irs~ mounting pin 70. The shield I5 is rotated abou~
i~s~bearing line on the fir~t mounting pin 70 unt~l ~he base
20~ ~ o t~e J 50 comes to bear against the second mounting pin 72. ~:
W~en positioned in this way, the fi1a~ent/shîe1d subassembly
is inlprecise~alignment between ics own eLements and relative
to ~he lamp reflector 14.~; ~The mounting flange 34 and first ; :~
mounting pin 70 are welded~together along their line o
contact:.: The base o the J 5Q and the second mounting pin 72 :~ :
are we1ded together at their contact . The ~ Qng leg of the
J :4~ is thereupon cut away to remove the~ electric.al sh~rt
_
:, ~ ~ . :
: ~ ~ . . . . .
~ 7 ~ ~ ~3
circui~ previously existing across the fil.ament 12. Fig. 8
shows the resulting configura~.io~. Mechanical support and
one electrical connection to the filament 12 is provided
through the first mount;ng pin 70, the body of ~he -Eilament
shield 15, and tha bump 40 to the short filament ~.eg 56.
The strength and rigidity of the first m~unting pin 70 is
sufficie~t by itself to support the filament shield lS and
:Eilament 12 against mechanical movement. The 6econd mounting
pin 72 merely provides the second electrical connectioI~ ~o
. the :Eilament 12 through the remaining portions of the J-shaped
pro~ection 44 and the long filament leg 54. The 6econd
mou~ting .pin 72 also provides mechanical support for on- end
o ~the :filàme~t 12. ~ : :
''- ' :' ' : '
, .
., . . . . , . . . ~ . .
.. . . ..
.` ' , . .
. ~ . . , :
:
:~: - -
.
'
.
'
,
