close

Вход

Забыли?

вход по аккаунту

?

Патент USA US3020445

код для вставки
Feb. 6, 1962
H. c. MEAD
3,020,435
FILAMENT SHIELD
Filed June 29, 1960
IN VEN TOR.
[A TTOPNEY
Unite grates
3,029,435
Patented Feb. 6, 1962
1
2
distributing media on the lens so as to stlike highly pol
3,020,435
ished surfaces protruding forwardly from the plane of
FILAMENT SHIELD
Howard C. Mead, Anderson, Ind., assignor to General
Motors Corporation, Detroit, Mich., a corporation of
Delaware
Filed June 29, 1960, Ser. No. 39,643
2 Claims. (Cl. 313—117)
the headlamps, such as chrome-coated bumpers and trim.
As a consequence, such direct downward ?lament light
is redirected upwardly by such highly polished surfaces.
Thus, in certain, vehicle installations, the problem of up,- ward spill or glare light may be occasioned by light rays _
passing forwardly from the lower beam ?lament both
The present invention relates to vehicle headlamps
above and below a horizontal plane approximately
having two ?laments which are adapted to selectively 10 through the ?lament.
produce either a high or road beam or a low or depressed
Accordingly, it is a principal object and feature of this
passing beam and, in particular, to a shield for intercept
invention to provide an improved shield for a ?lament
ing certain glare-producing light rays directed forwardly
of a headlamp to render the latter substantially free of
from the lower beam ?lament both above and below
upward spill or glare light emanating directly from the
a horizontal plane approximately through the ?lament. 15 lower beam ?lament both above and below a horizontal
Conventional automobile headlamps currently in use
plane approximately through the ?lament.
today typically comprise an all-glass concave or general
‘It is yet another object and feature of this invention to
ly paraboloidal re?ector and dished cover glass or lens
provide a ?lament shield of the type aforementioned-I
having their mating peripheries fused together to form a
which, while intercepting direct light rays projected for
sealed envelope enclosing two ?laments adapted to be
selectively energized to provide a high or low beam. Each
of the ?laments is axially coiled and ?xedly mounted
within the lamp envelope with its major axis generally I
horizontal and parallel to the axis of the other ?lament.
Moreover, these ?laments are positioned in a predeter
mined position with respect to each other and the focus
of the re?ector depending upon the particular type of
wardly from a ?lament both above and below a hori
zontal plane through the ?lament, still permits passage of '
certain unobjectionable light rays which are then avail~ able for side-lighting or lighting areas generally to either
lamp in question.
erally horizontal axially coiled ?laments adapted to be ,
a
side of the path of the vehicle.
In general, these and other objects and features of this .
invention are attained in a headlamp construction of the
type comprising two vertically spaced laterally offset gen
For example, in one type of automobile headlamp
selectively energized to produce either a high or low beam _
presently in use, the upper beam ?lament is disposed hori 30 of the required characteristics, and a light-intercepting
zontally within the re?ector and is located approximately
shield disposed immediately in front of the ?laments and "
at the focus of the re?ectoigwhile the lower beam ?la
having spaced upper and lower portions in predetermined
ment is located slightly above and to one side of the
positions with respect to the lower beam ?lament so as
upper beam ?lament. In another type of headlamp,
to intercept a substantial portion, but not all, of the light
commonly referred to as a Type II lamp, the horizon 35 rays directed forwardly from the lower beam ?lament
tally disposed lower beam ?lament is located approxi
both above and below a horizontal plane approximately,
mately at the focus of the re?ector, while the upper beam
through the ?lament, while permitting passage through
?lament is located slightly below and to one side of the
the shield of certain remaining and selected light rays
lower beam ?lament. In passing, it might be noted that
which are available for lighting the side of the roadway,
one variety of such a Type II lamp is known as a seven
street signs and the like, while not resulting in any ob~
inch lamp because of its diameter, and is employed in a
jectionable glare.
single lamp installation on each side of the front of the
The manner in which the foregoing objects are attained
vehicle. Another variety of such a Type II lamp is
will become more apparent hereinafter as the descrip
known as a ?ve and three-quarter inch lamp, and is uti
tion of the invention proceeds, and in which reference is
lized in dual lamp installations on each side of the front 45 made to the following drawings in which:
fender of the vehicle.
FIGURE 1 is a vertical section through a modern ve
Irrespective of the particular type of headlamp in
hicle headlamp equipped with the invention, and is taken.
volved, the dual ?laments of any given lamp are adapted
on line 1—1 of FIGURE 2;
to be selectively energized to provide either a high sym
FIGURE 2 is a fragmentary front elevation of a mod- ’
metrical road beam suitable for country driving purposes, 50 ern day automobile headlamp equipped with the present
or a lower or depressed asymmetric beam suitable for
invention, with certain parts broken away to illustrate cer
use when passing other vehicles. To this end, the lamp
tain details of the invention;
t
lens is provided with suitable light-distributing media such
FIGURE 3 is an enlarged section taken on line 3—3 of .
as light-spreading ?utes and vertically up-bending and
FIGURE 2; and
down-bending prisms to provide the aforementioned road 55 FIGURE 4 is an enlarged plan view of the ?lament
and passing beams meeting speci?cations as set therefor
by the motor vehicle industry. However, because of the
particular character of such light-distributing media, and
particularly the vertically up-bending and down-bending
prisms, a problem is presented with respect to an appre
ciable amount of upward and downward spill light which
is unavoidably produced from the lower beam ?lament
of the headlamp. Such spill light becomes an annoying
and sometimes blinding glare when re?ected into the eyes
of the vehicle operator by fog, snow, rain, dust and the
like, or directed into the eyes of the operator of an on
coming vehicle.
At this juncture, it should be noted that such spill or
shield of FIGURE 2.
.
.
Referring now to the drawings, the numeral 2 indi
cates an all-glass sealed beam lamp comprising a con
cave or generally paraboloidal re?ector 4 having a suit- >
60 able re?ective coating on its inner surface 6, and a dish»
shaped lens 8. The peripheral rims of the lens. and re
?ector are fused together as indicated at 10 to form a
sealed envelope for the dual sources of concentrated light
in the form of an axially coiled generally horizontally‘
disposed lower beam ?lament 12 and a similarly formed
and disposed upper beam ?lament 14. As is the usual‘
practice, the two coiled ?laments are suspended within
the lamp envelope on the inner ends of a suitable number
glare light is occasioned not only by light rays directed
of lead wires, indicated generally at 16, which extend‘v
upwardly from the ?lament, but also from direct light 70 through the base of the re?ector 4 and are electrically
rays which pass forwardly and downwardly through the
and mechanically connected to the thimble-like contact;
lens and are refracted downwardly further by the light
structures 18 accessible from the exterior of the reflec-f
3,020,435
3
4
Having described a conventional and well known lamp
tor. Inasmuch as the lamp illustrated is of the Type II
variety, the lower beam ?lament 12 is located approxi
mately at the focus of the re?ector, although not neces
construction and the glare problem introduced thereby,
reference will now be made to the ?lament shield 22 which
sarily exactly centered laterally thereon. The upper
beam ?lament 14 is located slightly beiow and offset to
the left from the lower beam ?lament 12 as viewed in
FIGURES 2 and 4.
The light-distributing lens 8 of the headlamp is pro
vided in the usual manner with suitable light-distributing
media, preferably on the inner surface of the lens, for 10
distributing the rays of light projected from the re?ecting
not only substantially eliminates the problem of glare
from direct upward spill light from the ?lament 12, but
also the similar problem occasioned by downward spill
light which is susceptible to refraction by the draft cor
ners and bases of the vertically up-bending prisms so as to
be directed toward and rte-re?ected upwardly from highly
polished surfaces on the vehicle protruding forwardly
from the lamp.
Referring particularly to FIGURE 4, the ?lament shield
surface 6 so as to produce, upon selective energization of
the ?laments 12 and 14, a lower passing beam and an
22 may be seen to have a generally “bow-tie” in that it
upper driving beam conforming to the speci?cations set
therefor by the motor vehicle industry. For this pur
pose, and according to conventional practice, the lens 8
comprises vertically spaced upper and lower shield sec’
tions 24- and 26, respectively, joined by a relatively nar'
row and integral centrally located bridge or neck portion
is divided into a series of sections or “patches” which
are provided as required with a plurality of small light
the form of a truncated 160° sector of a circle, with the
28. More speci?cally, the upper shield section 24 is in
spreading ?utes for horizontally spreading the light pass
truncated edge thereof joined or formed integral with the
ing through the lens. As is well known in the art, cer 20 upper portion of the bridge or neck 28 as indicated in
tain of such ?utes in diiferent portions of the lens pro
vide different degrees of spread in order to impart the
dotted lines at 30. In similar fashion, the lower shield
section 26 is in the form of a truncated 100° sector of
the same circle from which the upper shield section is
required horizontal spread to the beams projected by the
lamp. Furthermore, certain of the sections or ‘: patches”
of the lens are provided with vertically tip-bending and
sectorized, and is formed integral with and joined to the
lower portion of the bridge 28 as indicated in dotted lines
down-bending prisms indicated at 2% in FIGURE 1 so as
at 32.
to refract the light rays passing therethrough to provide
the required vertical distribution of the light in the beams
upper and lower shield portions from each other so as to
The neck 28 rigidly joins and vertically spaces the
projected by the lamp.
provide notches or openings between the shield sections
In the manufacture of lenses provided with such prisms 30 on each side of the neck 28. The upper shield section 24
20 for bending light rays vertically, the ends or extremities
of the prisms must be provided with a slight amount of
draft in order to permit separation of the lens from the
is symmetrically disposed on either side of a vertical plane
through the center “C” of the shield so that the radial
edges 34 thereof extend upwardly at an angle of approxi
mately 10° with the horizontal. In similar fashion,
known in the art, the bases of such prisms have rounded
the ‘lower shield section 26 is symmetrically disposed with
corners which constitute, in conjunction with the base
respect to the aforementioned vertical plane with the radial
surface itself, small secondary lenses which direct the rays
edges 36 thereof extending downwardly at an angle of
of light striking it in a direction opposite to that of the
approximately 40° with the horizontal. Thus, and as will
rays refracted by the prism itself. These corners of the
appear more fully hereinafter, the notches or openings in
aforementioned down-bending prisms, as well as the ?at 4-0 the shield formed by the neck 28 and the opposed radial
base surfaces thereof, direct the rays of light striking them
edges 34 and 36 of the shield sections will permit direct
upward from the headlamp. Consequently, these corners
light to pass from the lower beam ?lament 12 slightly
and base surfaces of the down-bending prisms constitute
above and to a greater extent below a horizontal plane
sources of light in. the lens itself which create a consider
through the center “C” of the shield. The arcuate edge
able amount of upward spill and glare light which, when
portions of the upper and lower sector-shaped shield sec
added to the upward direct light from the lower beam
tions each include a ?ange 38 which is bent axially rear
?lament 12, creates an upwardly directed curtain of spill
wardly at a right angle to the plane of the shield sections
and glare light from the headlamp which may become
to provide additional light-intercepting surfaces, while a
blinding when re?ected back into the eyes of the driver
Y-shaped depression 40 centrally and symmetrically dis
by fog, mist, rain, snow, dust and the like, as well as into 50 posed with respect to the shield 22 provides reinforcement
the eyes of a driver of an oncoming vehicle. In similar
therefor.
fashion, such corners and ?at base surfaces of the up
From the foregoing description, it may be seen that the
bcnding prisms constitute secondary sources of light in
shield 22 may be manufactured from a circular sheet of
the lens itself which create a considerable amount of
material, such as sheet metal, by notching the circular
downward spill light which is re?ected from highly re 55 sheet radially inwardly from opposed portions of the
?ective portions of the vehicle protruding in front of the
periphery thereof to de?ne the upper and lower shield
headlamps, such as the front bumper, and is directed
sections 24 and 26 and connecting bridge 28 therebetween,
upwardly to provide an additonal source of glare light.
followed by bending of the ?anges 38 axially rearwardly
In order to reduce, although not eliminate, this prob
as aforedescribed.
pressing plunger of the molding apparatus. As is well
lem of glare at least with respect to light from the lower 60
A wire 42 is suitably secured as indicated at 44 to the
beam ?lament directed forwardly therefrom and above a
upper shield section 24, and similarly secured to one of the
horizontal plane, it is common practice in some lamps to
lead Wires 16 so as to mount the shield immediately in
tilt the axis of re?ecting surface 6 downwardly at a slight
front of the ?laments 12 and 14. More speci?cally, and
angle from the horizontal plane, and also to the right a
referring again to FIGURE 4, the shield is preferably
few degrees when viewed from behind the re?ector. Such 65 positioned so that a vertical plane through the center “C"
an expedient aids in properly directing the lower beam
thereof passes approximately through the mid-point of
projected from the ?lament 12 down and to the right when
lower beam ?lament 12, while a horizontal plane through
the center “C” generally contains the lower edge of the
?lament coil. Moreover, the axis of ?lament coil 12 is
viewed from the vehicle operator’s compartment, although
the light-distributing media aforedescribed is still required
for complete distribution of the desired lower beam as well 70 approximately in the horizontal plane containing the lower
as the upper beam. However, by so tilting the re?ector
edge indicated at 30 of upper shield section 24. The upper
axis relative to the horizontal, and as is well known in
beam ?lament 14 is correspondingly located in accordance
the art, the glare effect from direct upward spill light from
with its displacement from the ?lament 12 as previously
the lower beam ?lament is to some extent minimized,
described, it being noted that this ?lament is less shielded.
although far from eliminated.
75
Consequently, with the lower beam ?lament 12 ener
3,020,435
gized, the upper shield section 24 will intercept substan
6
tially all glare-producing light rays directed forwardly
shield comprising an upper shield section having the
shape of a truncated 160° sector of a circle and being
and above a horizontal plane generally through the center
of the shield or the axis of the lower beam ?lament; that
disposed substantially entirely above said horizontal plane
is, the upper shield section will intercept such direct light
rays in the solid angle subtended by approximately 160°
of the upper half of the lens 8. In similar fashion, the
lower shield section 26 will intercept glare-producing light
to intercept glare-producing light rays from said ?rst ?la~
ment in the solid angle subtended by 160° of the upper
half of said lens, a lower shield section having the shape
of a truncated 100° sector of said circle ‘and being dis
posed substantially entirely below said horizontal plane
rays directed forwardly from the lower beam ?lament 12
to intercept direct glare-producing light rays from said
below the horizontal plane aforementioned, and in the 10 ?rst ?lament in the solid angle subtended by 100° of the
angle subtended by approximately 100° of the lower half
lower half of said lens, and a relatively narrow centrally
of the lamp lens 8. On the other hand, the notches or
located bridge integral with and joining said shield sec-v
openings formed between the opposed shield sections to
tions to de?ne openings in said shield between said shield
either side of the neck 28 permit direct light rays from
sections on each side of said bridge to permit passage
the lower beam ?lament 12 to pass therethrough and 15 therethrough of selected direct light rays from said ?rst
through the lens toward either side of the vehicle for side
?lament toward the unshielded portions of said lens, a
lighting purposes and, while consisting substantially of
substantial portion of said second ?lament being located
light below the aforementioned horizontal plane, some
opposite one of said openings in said shield whereby a
light passes above said plane for illuminating signs and
substantial portion of the light rays therefrom in excess
the like along the roadway.
20 of said selected light rays from said first ?lament is per
mitted to pass through said opening toward an unshielded
From the foregoing description, it may be seen that the
portion of said lens.
?lament shield 22 is constructed and arranged relative to
2. A vehicle headlamp comprising a substantially pa
the lower beam ?lament 12 and the lens 8 so as to inter
cept glare-producing lightrays directed forwardly from
raboloidal re?ector, a ?rst coiled ?lament disposed in a
the ?lament both above and below the horizontal to pre 25 substantially horizontal plane, a second coiled ?lament
disposed generally parallel to and spaced a slight distance
vent corresponding critical areas of the lens from a glare
vertically and to one side of said ?rst ?lament, one of
producing standpoint from receiving any such rays, while
said ?laments being located approximately at the focus
at the same time permitting unobjectionable direct light
of said re?ector, a lens covering said re?ector and pro
rays to pass through the openings on either side of the
shield for side-lighting purposes. Viewed in another way, 30 vided with vertically up-bending and down-‘bending
prisms for distributing light rays re?ected by said re
an area on the inner surface of the lens 8 corresponding
?ector upon selective energization of said ?laments to
to the con?guration of the shield 22 is masked from any
provide a lower beam from said ?rst ?lament and an
such objectionable direct rays from the ?lament 12, while
upper beam from said second ?lament, a ?lament shield
two generally horizontally opposed portions on the lens
are unmasked and will receive and transmit direct light 35 comprising an upper shield section having the shape of a
truncated sector of a circle and being disposed substan
rays from the lower beam ?lament for side-light purposes.
tially entirely above said horizontal plane to intercept
In this regard, it will be appreciated that the portions of
glare-producing light rays from said ?rst ?lament in the
a lens to be masked or shielded will depend upon variables
solid angle subtended by less than all of the upper half
such as the tilt of the re?ector, the location of the ?lament
12 and the particular nature and arrangement vof the light 40 of said lens, a lower shield section having the shape of
a truncated sector of said circle and being disposed sub
distributing media on the lens in accordance with the
stantially entirely below said horizontal plane to inter
character of the projected beams desired. Thus, the
cept direct glare-producing light rays from said ?rst ?la—
angular extent of the upper and lower shield sections may
ment in the solid angle subtended by less than all of the
be varied in accordance with such considerations.
While but one form of the invention has been shown 45 lower half of said lens, and a relatively narrow centrally
located bridge integral with and joining said shield sec
and described, other forms will now be apparent to those
skilled in the art. Therefore, the embodiment shown in
the drawings is merely for illustrative purposes, and is not
intended to limit the scope of the invention which is de
?ned by the claims which follow.
50
I claim:
1. A vehicle headlamp comprising a substantially pa
raboloidal re?ector, a ?rst coiled ?lament disposed in a
substantially horizontal plane and approximately at the
focus of said re?ector, a second coiled ?lament disposed
generally parallel to and spaced a slight distance below
and to one side of said ?rst ?lament, a lens covering said
re?ector and provided with vertically up-bending and
down-bending prisms for distributing light rays re?ected
by said re?ector upon selective energization of said ?la
ments to provide a lower beam from said ?rst ?lament
and an upper beam from said second ?lament, a ?lament
tions to de?ne openings in said shield between said shield
sections on each side of said bridge to permit passage
therethrough of selected direct light rays from said ?rst
?lament toward the unshielded portions of said lens, a
substantial portion of said second ?lament ‘being located
opposite one of said openings in said shield whereby a
substantial portion of the light rays therefrom in eXcess of
said selected light rays from said ?rst ?lament is per
mitted to pass through said opening toward an unshielded
portion of said lens.
References Cited in the ?le of this patent
UNITED STATES PATENTS
1,998,967
2,880,347
Reynolds ____________ __ Apr. 23, 1935
Flaws et al ___________ __ Mar. 31, 1959
Документ
Категория
Без категории
Просмотров
0
Размер файла
622 Кб
Теги
1/--страниц
Пожаловаться на содержимое документа