Aug. 16, 1927.
'
~
J. G. BALSILLIE
1,639,363
'
LIGHT PROJECTING REFLECTOR
Filed June 6, 1924
2 Sheets-Sheet 1
A 0mm
Aug. 16 , 1927.
1,639,363
J. G.|BALSILLIEy
LIGHT PROJECTING REFLECTOR
Filed June 6, 1924
2 Sheets-Sheet 2
//ll
12'
,/(s'
_ (avg-M OR’
A
NW
Patented Aug. 16, 1927.
*
1,639,363‘
UNITEDV'YSTATES ‘PATENT ‘OFFICE.
JOHN 'GRAEME BALSILLIE, ~OF MELBOURNE, VICTORIA, AUSTRALIA, ASSIGNOR, BY
MESNE ASSIGNMENTS, 'I‘O THE'AMERICAN FLATLITE COMPANY, OF CINCINNATI, '
01110, A conronarrro'u or 01110.
LIGHT-PROJECTING REFLECTOR.
Application ?ledil’une 6, 1924. senaino. 718,288.
This invention relates to a light projecting
re?ector for vehicle head lamps, which has
been developed, with an object in view of
producing a construction designed to project
median as indicated by the line 41—4 of Fig
1. The embodiment I have disclosed is such
that the sectors above the horizontal median
are identical with those ‘below the hori
5 a beam of light complying in a‘ general sense zontal median and the sectors 8 and 9 which
with the requirements of the varying laws lie on each side of the re?ector are separated
of the several States having regulations de by the horizontal line 4—4 so that half of
signed to govern vehicle road lighting, and each of these sectors lie on each side of the
. which, in addition to meeting these require horizontal median. These sectors are prefer~
10 ments 'in a novel manner, simultaneously ably of the largest dimensions and the next
lends itself to very simple and relatively in largest in width are those which extend ver~
expensive manufacturing conditions and tically and are designated ‘by numerals 10
methods.-
15
55
65
and 11. These vertical sectors ‘are split by
'
These and other objects are attained in the vertical median as represented by line
the. re?ector described in the following spec 3—3 in Fig. 1, so that one-half of each sec
i?cation and illustrated in‘the accompanying tor lies on each ‘side of the median. Between
drawings in which’:
'
each of the horizontal sectors 8 and 9 and 70
Fig. I is a front elevation of a re?ector the vertical sectors 10 and 11 I have divided
‘embodying my invention.
'
the re?ector surface into a series of sectors of
20 Figf2 is a somewhat diagrammatic view smaller angular breadth and decreasing in '
showing the shape of light pattern produced width from the vertical sectors toward the
by the re?ector shown in Fig. 1.
25
adJacent edges of the horizontal sectors.
75
Fig; ‘3 is a vertical sectional view‘ of the The sectors 12, 13, 14, 15, 16, 17 and 18 which
re?ector shown in Fig. 1 and taken on the lie on each side of the vertical sector 10, are I
line 3-—3 thereof.
preferably of the same angular breadth as
Fig. 4 is a horizontal sectional view of are the corresponding sectors 12', 13', 14.’,
' the re?ector shown in Fig. 1 and taken on 15’, 16',’_17', and 18', which lie on each side
.
the line 4—4 thereof.
30
3 in
80
of the lower vertical sector 11. The horizon
Fig. 5 is a fragmental sectional view taken tal sectors 8 and 9 are divided into a series
on the line 5--5 of Fig. .3.
of vertical stripes 19, 20, 21, 22, 23, 24, 25
The re?ector which~I haveillustrated as and 26 _which are preferably of uniform
an embodiment of my invention, has been width, although, if desired they may be of
shaped somewhat upon a curvature basis varying width as are the sectors,v depending
,
v
which is preferably that a hyperbola or upon the ‘results desired.
which may be av parabola, an ellipse or a
‘In as much as the example of light pat
combination Iof these curves. _ The rear or‘. tern to be produced has been shown as of
85
apex end of the re?ector is provided with the shape disclosed in Fig. 2, it is necessary
an aperture 5.adapted to receive the usual that the various sectors and stripes be of
focusing tube and electric lamp bulb which the transverse cross sectional and other
40 furnishes the source of light. The forward shape shown and the various features of
90.
openend of ‘the re?ector is provided with a ' which will be described shortly. However, 1
grooved rim 6 in which may be’located a theshape of each‘ ofthesectors and stripes
95
_ packing , cord which cooperates with the may be materially varied in order to pro
lamp closure when the re?ector ls-to be duce a light pattern which complies fully . i.
45 closed against the admission of dust and with the requirementsof thestates in which
moisture thereto. The outer edge of the re such re?ectors are to be used, such varia
?ector is provided with av ?ange 7’_wl1ich is tions in no way requiring a departure from 1/00
adapted to support .the re?ector within the the general principle upon vwhich'my im
5O
mounting bodyof the lamp, as is usual in proved re?ector functions. ' In‘ the exem
lamp construction.
.
_
.
plary light pattern I have disclosed invFig.
The bowl of the re?ector is divided into a 2 will be found a central portion 27 which
~series of sectors of varying shapes and sizes, is somewhat elliptical in general outline and
which extend above and below the horizontal which is intersected by a portion 28 which'is/
105
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1,639,363
of an elongated elliptical shape and which
projects beyond the center portion 27 at each
side. The-production of this composite pat
tern is brought about by the superposition
and angular crossing of a number of sub
beams which I have indicated by dotted out
lines 29iand 30, each of these sub-beams is
5
road, the central portion 27 will still func
tion to disclose distant objects while the nar
row side projection of portion 28 will be too.
narrow to project a glaring light into the
eyes of the driver of an approaching vehicle, ”
even though this portion of the beam be
somewhat elevated.
Change of general contour of the exem
produced by one of the sectors and its cor
responding sector located on diametrically. plary light pattern disclosed in Fig. 2. may
,10 opposite sides, or by one of the stripes and be desirable and may be easily accomplished
its corresponding stripe located on the op in order to bring the pattern within the re
posite side of the re?ector. The somewhat quirements of the laws designed to regulate
' elliptical center section 27 of the light pat such matters. In the development of the
tern, shown in Fig- 2, is made up of the re?ector I have disclosed herein I have clic 80
sub-beams which are projected from the sec covered a few general principles upon which
tors 10, >11, 12, to 18 and 12’ to 18’ inclusive. the projection of the required pattern de
The elongated elliptical portion 28 of the pends. I will endeavor to set forth in a
- pattern disclosed in Fig. 2 is composed of few brief statements the general principles
sub-beams projected from the stripes 19 to governing the variation of the shape of the
20' 26 inclusive located on opposite sides of the pattern to be produced by the re?ector eni
re?ector apex. Thus the composite beam bodying my invention. In order that the
produced by the series of superposed and somewhat elliptical portion of the beam dis
angularly disposed sub-beams, will assume closed in Fig. 2 may be produced, I have
the general shape suggested by the total pat discovered that the sectors lying between 00
the horizontally positioned sectors 8 and 9,
25_ tern disclosed in Fig. 2.
The practical desirability of such a pat must be of varying width, the width of the
sectors decreasing from the vertically posi
tion performed by its peculiar shape. In tioned sectors toward the adjacent edges of
the ?rst place the somewhat elliptical cen the horizontally positioned sectors. The
tern is readily seen in the three-fold func
30~
trally located portion 27 operates to illumi
nate the roadway directly in front of the
vehicle and for a considerable distance ahead
of the vehiclewith a ribbon of light having
’- a relatively narrow spread, thus forming
35 the far-reaching beam which is necessary
ellipticity and distribution of the center por
tion of the light pattern depends upon an
gular position, angular breadth and‘ trans
verse sectional curvature of sectors and the
‘amount of ellipticity and distribution can
be controlled by varying one or more of
for the disclosure of objects at a sufficient these factors. The elongated elliptical por
distance in front of the vehicle to render tion of the light pattern is projected by the
driving more safe at night. This narrow vertical stripes in sectors 8 and 9. The
ribbon, of- light also has the advantage of transverse cross section of each of these
preventing a wide-spreading far-reaching stripes is different from that of the corre
beam-of light being projected into the eyes sponding portion of, the general or basic
of the driver of an approaching vehicle as curvature upon which the re?ector is de
well as pedestrians. However. the sides of signed. The stripe cross section may vary
the road would not receive su?icient illumi therefrom so as to be somewhat convex, and
nation to disclose ditches, embankments and should greater ellipticity be required it is
objects located at the side ,of the road and necessary to increase this‘convexity.
I have also discoveredthat when the sec
for this reason the elongated elliptical por
tion 28 has been provided to furnish the tors 10 to 18 and 11 to 18’ lying between
50
necessary roadside ‘illumination.
Such a the horizontal sectors 8 and 9 are made of
relatively narrow but wide beam of light uniform width and are less convex in trans
will not afford illumination of the road sur
face at a ‘great distance ahead of the vehi
cle but will function to illuminate the en
verse cross section the central, portion 27
of the‘light pattern will be substantially
circular. Upon these principles and upon
tire. road surface immediately in front of their variation in combination and degree,
the vehicle so that both sides of the road depends the production of any light pattern
are disclosed. Because-of thevnarrow char which may be required to meet the require—
acteristics of this portion of the totalbeam ments of the several States providing laws
for the regulation of vehicle high-way
. . projected by the vre?ector, the light- rays are
illumination. \
,
held
comparatively
close
to
the
ground
and
60
Thus it will be seen that the latitude in
will not operate to create glare in the, eyes
of the driver of an approaching vehicle; the variation of the. widths, ‘cross sectional
Another advantage attained by t is combina shapes and in the number of sectors and
tion of elliptical beams is that when the stripes, may be varied infinitely in order to
produce the required results, the permissible
65 vehicle passes to the side of the road so that variation in the position of the stripes, as to
it tips after having left the crown of the
55
125
130
1,689,868
angularity, etc., also operating as govern
in
in?uences in- the production of the re
quired light pattern.
'
.
Having thus described my invention what
‘ I claim 1s:
’
45
A re?ector of concave formation, consist- .
I am aware that re?ectors have been con ing of a' series of sectors, certain of said
structed heretofore upon lines resembling sectors consisting of a series of vertical
quite closely the radiating sector-like por stripes having contiguous edges of substan
tions of the re?ecting surface of my im tially parallel disposition relatively to each
proved re?ector, and that re?ectors have other, the striped sectors being arranged
heretofore been constructed with a re?ect horizontally opposite each other with each
ing surface made up-in its entirety of stripes containing substantially the same number
50
or portions of stripes extending substan~ of stripes as the other striped sector, the re
tially vertically of the re?ector, but I am maining of said sectors being arranged in
not aware of any construction which dis two vertically opposite groups, each of
55
other portions consisting of a number of tively wide angular sector located at the
60
closes a re?ecting surface of a composite which contains substantially the same num
nature in which portions thereof are made ber of sectors, each of the vertically oppo
up of radiating sector-shaped sections, with site groups of sectors consisting of a rela
substantially vertically extending stripes. center of each of the vertically opposite
Particularly do I consider the formation of groups of sectors, and a series of sectors of
the re?ecting surface to be a novel one in decreasing angular width located upon each
the making of the entire surface into sector side of each relatively wide centrally located
shapes with certain of the sectors divided angular sector of the vertically disposed
into stripes of decreasing lengths from the groups of sectors, with the narrowest one of
rim of the apex. ,
‘
._
the sectors of decreasing angular width on
In re?ectors of the substantially vertical that side of the adjacent relatively wider
stripe type the stripes decrease in' length angular sector which lies toward the series
30
from the center of the re?ector toward each of horizontally opposite vertically striped
side thereof until the opposite longitudinal sectors, the transverse cross section of each
edges are reached. This type of re?ector of the vertically disposed stripes of the hori
produces a trulyv elliptical beam without the zontally disposed sectors and the "transverse
centrally located distance piercing portion
b5 LI
(0
of the somewhat elliptical shape. In the re
?ector I have disclosed herein the reverse
condition of the stripes is true. The de
crease in length of these stripes takes place
second mentioned vertically opposite groups
75
of sectors varying from the general concave
formation of the entire re?ector, whereby
of the sector shaped circular beam produc a horizontally elongated ellipse.
In testimony whereof I have hereunto
thus being properly pro ortioned to re a?ixed my signature.
duce the side extensions 0 the elliptical part
of the light pattern.
70
cross section of each of the sectors of the
a sourceof light placed at or about the focal
from the opposite horizontal edges toward center ofthe re?ector will produce a pro~
the center, thus leaving the remaining por jected beam of desired contour and light in
tions of the re?ector free for the formation tensity distribution conforming generally to
ing sections thereon, the striped. sections
65
JOHN GRAEME BALSILLIE.
80