US1773245A - Glare-preventing device - Google Patents

Description

Aug. 19,. 1930'. s. E. TALBOT' I 1,773,245

GLARE PREVENTING I DEVICE Filed Nov. 17, 1927 s Sheets-Sheet 1 Mrs/wa STANLEY [an M12 new 50.7

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Aug. 19, 1930. s. E. TALBOT 1,773,245

GLARE PREVENTING DEVICE M Filed Nov. 1'7, 1927 5 Sheets-Sheet 2 Aug. 19, 1930. s. E. TALBOT 3,

GL'ARE PREVENTING 'VDE'VICEJIQ.

Filed Nov. 17, 1927 5 Sheets-She et 5 Patented Aug. 19, 1930 UNITED STATES,

PATENT om STANLEY EDWARD TALBOT, or WIMBLEDON, ENGLAND, i Y

' GLARE-PREVENTING DEVICE Application filed November 1:, 1927, Serial No. 233,953, andfin- Great Britain December 9, 1926.

This invention relates to vehicle headlights, particularly the headlights of motor road vehicles, and refers to headlights of the known kind incorporating means for preffi 'venting side glare andrestrictingthe angle of diversion of the light beam, consisting of a plurality of rings of varying depths arflector through any one of said annular spaces, is determined by the'location of the front edge of the outer encircling ring of said space in relation to-the rear edge of the adjacent inner ring. That is to say, if an imaginary straight line be drawn passing through points corresponding to said inner and outer edges, such line, extended beyond the front of the lamp, corresponds to the angle of greatest diversion of the light rays projected through the annular space.

Hitherto, in lamps incorporating sideglare preventing devices of the kind set forth, all the annular rings have been equally spaced apart or the said spaces between adjacent rings have been varied withoutconi forming to any predetermined order, rule or sequence.

It will be apparent from the foregoing remarks that the angle of greatest diversion of a light beam projected through one of the annular spaces, and corresponding to the straight line aforesaid passing through the front and rear edges of adjacent rings, is governed by two factors, namely, the space between the adjacent rings and the depth of said rings. If one of said factors be altered without corresponding adjustment of the other factor, the aforesaid line of greatest diversion will be accordingly of a greater or lesser angle, and if the depth of the rings varies from widest rings in the centre to narspace.

rowest' rings at the outside, whilstthe spaces between adjacent rings remain constant, such arrangement having already been proposed, then the shafts of light projected from differ ent annular spaces-vary as to the angle of 65 diversion, those spaces towards the periphery of the lamp giving the greatest angle of diversion. The present invention, providing means for preventing side-glare from a-headlamp, and i for restricting the angleof diversion of the light beam, consisting of annular rings of varying diameters concentrically arranged within one anotherat the front of the lamp as hereinbefore described, is characterized in that the consecutive annular ,spaces between the rings vary inwidth according to the depths of the rings which divide said spaces .from one another. That is to say, as the depths of the rings decrease in size from 7 those nearest'the centre of thelamp to those nearest the outside, so the annular spaces bep tween adjacent rings also decrease in width in the same proportion; In other words, the

annular space between a certain ring and the adjacent larger one is indefinite proportion to the depth of the said larger ring, the same rule applying for each annular Such decrease in the depth a and width of spaces, may also be proportionate to reduction in the concavity of the reflector towards itscircumference.

It will be apparent, therefore,that as the annular spaces between the saidrings consecutively diminish in width from the centre of the lamp towards the periphery thereof in relation and proportion to the. width of the adjacent rings, and on accountof this compensation between the one'and other, if an imaginary straight line as previously described is drawn' through each annular space through points corresponding to the inner and outer edges of each ring, all the said imaginary lines so drawn in either, an up- 93 wardor downward direction will be parallel, and since these imaginary lines represent the'angles of greatest diversion for the respective spaces the angles of greatest diver sion will be the same in the case of each space 1m of the rings 80 and the light beams projected will be screened to an equal degree simultaneously by each a he front edges of the rings preferably are flush with one another in a line parallel to the window or lens of the lamp.

The space constituting the area within the innermost rin tleeed, and the arrangement of the w ole assembly of rings is such that no direct rays from the illuminant are projected in front at the lamp at any point, the entire beam from the lam being reflected light. The rings themse ves do not interfemito an appreciableextent with horiaontalzefiecte' rays. The inner closed ring f m, "d mwybe anganxiliary ring whose depth-1s or is notieproportion to that of mam as hereinbefore described.

Inmdemha the inizention may be the imore'z'eadilynnderstooda device of practical cor atliqc'tionuin aocordahcetherewith is illustraiedc in the ,ncccmpanying drawings, wherein F'igm'e 1 is a vertiealgsection through said complete device, a lampto which it is applied being "indicated by dotted lines.

Figure? is a plan view of a. support for th'e'"r1ngs, 7 hereinafter described.

Fifhre 3 is a plan view of the ring ashereinafter described; and,

Figure 4 is aplan View of the rings and theireufiport assembled together, a lamp beingihdicated bydotted lines.

f5 is a front view of the device I gfisame applied'toa base ring.

dis an edge view of the front inter "pg ringportlons shown in F igure 5.

of a panel with frosted Figure 9 is a faceofsaid litidgolthedevice, the latter ing shown in dte lines? fipen di ghparti in the several views arfi mdicated by the same reference nulass panel a p h P d I morale.

In the construction Shown in the said drawings, rings 1 are sup rted by a pair ofsubstantr ly trian lar p ates 2 (omitted in I'figurel or the eof-clearness) longitqdinally arranged within the lamp and formed with slots fgr theengagement of the rin 1, said platesz be ng perpendicular to an igterseptingone anather, and each being slotte Alt; its centre for" the engagement of theother. ,Preferably the said plates are are'- each at approximately 45 de rees tote horizontal. he longest sides o the said plates 2 are at the front of the lamp, animal; be fl sh with the front edges of the rings J, and the remaining sides 3 of said pl tescenyerge towards the source of illumination said plates being cut away at their as indimtadat 4: to accommodate Tandg "are' front and edge views the same purpose as the rings 1 aforesaid and interposed therebetween, said plates being of such a depth and so located between the rings that they adhere to the principle of the invention as above set forth. ,Said additional plates 6 constitute rings which are discontinned so that they are not present in one or more of the said segments, for instance, in the segment 7 as shown in the drawings.

It is desirable in connection with the headlam s of motor road vehicles to restrict the ang e of diversion of the light rays which extend upwardly and to the sides whilst not restricting the angle of diversion of the downwardly directed raysto the same extent, so that the road is illuminated near the vehicle, and in order to produce such an effect the additional arcuate plates or interrupted rings 6 aforesaidmay be continued through the upper and side segments whilst not being present in the lowermost segment or segments.

In connection with the said lower or other segment or segments into which the additional arcuate plates do not extend, for instance, the segment 7 shown in Figure 5, there may be provided means which, whilst not interrupting the outwardlydirected rays whose angle of greatest diversion is limited by the rings in the manner aforesaid, limits the angle of the downwardly directed rays which are projected from said segment or segments and pass across the axis of the complete ray pencil tothe other of said axis; for instance, the rays upwardly directed from the lower segment 7. Such means may consist of a clear glass panel 8, shown in Figures 7, 8 and 9, fitted in front of the rings 1 contained in said segment, said glass panel having arouate frosted ground or similar translucent strips 9 formed upon it, one for each of the spaces 10 between adjacent rings. The inner edge of each ofpthe said frosted or ground strips 9 is, coincident with the innermost ring 1 defining the space 10 with which said strip co-operates, but said strip is not so wide as the said space 10, so as to leave a clear outer portion 11 for the passage of the rays. In this case the frosted orground strips 9 serve to interrupt some of the inwardly extending rays, the angle of diversion of said rays being governed by the width of said strips, as indicated by the dotted lines a (Figure 1), but being ground or frosted they do not totally obscure and waste all the interrupted light, although they could be made opaque, is so desired. Conveniently, the frosted or ground strips 9 may be of such a width as to make the extreme inwardly directed rays a (Figure 1) substantially arallel to the extreme outwardly divergmg rays 6 projected from the diametrically Opposite part of the lamp front.

The said glass panel 8, triangular-shaped in accordance with the configuration of the segment 7 with which it co-operates, may be attached in position by screws or by any other suitable means. For instance, it may be attached by a screw 12 at its apex to a metal or other disc 13 which closes the front end of the innermost ring, and at its curved periphery by a clip 14 fixed to an annular frame ring 15, by which latter the complete ring assembly and the triangular plates 2 are fixedly carried, as hereinafter described.

The invention as above described can be embodied in a lamp as a component part thereof or it may be in the form of an attachment for a lamp. In the latter case, as shown in the drawings, the frame ring 15 to which the rings and triangular plates are fixedly attached is detachably, hingedly or otherwise carried by a base ring 16, which latter seats over the front flange 17 of the lamp reflector 18, the said annular frame ring 15 having projecting lugs 19 or the like adapted to engage under spring clips 20 on the base ring by rotating the said frame ring 15. Or, the base ring 16 may be eliminated, the frame ring 15 being hinged or otherwise mounted, or adapted to be mounted directly to the front flange 17 of the reflector to engage therewith by partial rotation in the said manner. Conveniently, in order to connect the frame ring 15 to the base ring 16 or to the lamp reflector in such a manner as to allow of the locking of said frame ring by partial rotation thereof, there may be provided on the said base ring or flange of the lamp reflector a fixed arcuate rod 21 lying on a circumference thereof, on which is mounted to rotate thereupon and to slide therealong, a

collar 22 to which is attached the frame ring 15. An additional springy tongue may be provided on one of the engaging parts adapted to engage a raised projection on the other part and effect a wedge-locking action by the relative rotation as aforesaid, such a device not being shown in the drawings.

In order to provide additional support for the rings, and for the arcuate plates if employed, there may be provided a number of thin wire rods 23 extending across the lamp front and attached to the said rings and plates.

The rings 1 may be finished to a dull black on one or both sides, although the inner under sides of the rings at the top of the lamp or in the top segment may be silvered or nickeled to reflect light downwardly on to the road surface.

In order that it may be clearly seen that the widths of'the spaces between the rings are in definite pro ortion to the depths of the rings, as 'hereinbe ore described, reference is directed ,to Figure 1 of the drawings, and the following descriptionl- As shown, the complete ring assembly is of cone formation, the apex of the cone outline d drawn through the inner edges of all the rings being on the axis of the ring assembly at the point marked d in Figure 1, at or in close proximity to the light source. The imaginary lines f represent the extreme light rays between the light source and the front edge of the lamp reflector, the cone outline d of the ring assembly being coincident wth or adjacent to and parallel with said imaginary lines 7.

The imaginary point 0 is on the axis of the ring assembly and positioned from the flat front of said assembly at one-sixth of the distance between the front of said assembly and the point d although it could be any other proportion of said distance. The imaginary lines 6 drawn from the point- 0 meet the plane of the flat front face of the ring assembly at the same points as the cone outline 03.

As will be seen by the arcs g in the lower half of Figure 1, the width of the space between any two rings is equal to the distance h between the front edge of the larger of said two rings and the point where the line e intersects said larger ring. Since said distance h is in direct and constant proportion to the total depth 2' of the larger ring in the case of each of the spaces, therefore all of the spaces have a width in direct and constant proportion to the depths of the respective rings. In the upper half of Figure 1 addi tional interrupted rings 6 are shown as hereinbefore described, positioned between the rings illustrated in the lower half of said view.

The device according to the invention, whilst adhering to the feature of equal angles of greatest diversion from all the spaces, affords large spaces towards the centre of the lamp front for the propagation of a maximum amount of light, whilst at the same time it does not interfere with the passage of direct light from the light source to the reflector.

Moreover, in the construction illustrated in the drawings, the glass lamp front may be opened for cleaning without disturbing the said device, whilst access may be gained to the interior of the lamp by simply swinging the device forwardly about its hinge connection, after giving it a partial rotary movement.

I claim Thecombination of a headlight and antiglare means therefor, said means comprising a plurality of concentrically arranged rings of different lengths, the longest of which is the innermost ring, each adjacent exterior

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