United States Patent
`
`1191
`
`1111
`
`4,024,388
`
`
`
` Skoff BEST AVAILABLE copy I 1451 May 17, 1977
`
`
`
`
`
`......... .. 240/7.1 R
`Schable .............
`3/1‘971
`3,567,918
`FOREIIGN PATENTS OR APPLICATIONS
`Al9,9l6
`8/l965 Germany ..........................240/7.55
`
`Primary Examiner—George H. Miller, Jr.
`Attorney, Agent, or F1rm—Seymour A. Scholmck
`[571
`ABSIRACT
`A cornering light system has a left beam and a right
`beam, each having a novel combination of cross sec-
`tional shape and orientation with respect to the vehicle.
`The cross sectional shape and orientation used have
`been found to provide optimum illumination of the
`roadway in the direction of turn. A two-wheeled vehi-
`cle necessarily leans toward thelilnside of the turn when
`cornering. As the vehicle tilts t e appropriate beam is
`tilted into an efficient orientation for illuminating the
`roadway. An electrical switch activated by tilt of the
`vehicle is provided to operate the appropriate beam
`.
`.
`.
`°"‘Y when the "eh‘°1e ‘S actually °°”‘°"“8-
`
`8 Claims, 13 Drawing Figures
`
`[54] CORNERING LIGHT svsTEM iron
`Two-WHEELED VEHICLES
`Inventor: Roger E. Skoff, Los Angeles, Calif.
`
`[75]
`
`[73] Assignees: Marvin H. Kleinberg, Inc.; Richard
`Morganstern Inc.; Seymour A.
`Scholmck, an of BeVefly_HinS, Cant
`Mar. 24, 1975
`
`[22] .Filed:
`
`'
`[21] Appl‘ No" 561’649
`[52] U.S. CL.......................... .. 240/7.55; 240/7.1 R;
`240/8_24
`Int. Cl.” ..................... .. B62V 5/00; B600 1/12
`[51]
`[58] Field of Search ___________ ,_ 240/7_1 R, 755, 62 R,
`240/62_2, 52,4, 58, 8,24
`_
`References Cned
`UNITED STATES PATENTS
`V
`6/1923 Hancock ........................ .. 240/62 R
`10/1923
`Showalterbaugh
`240/62 R
`12/1925 Calkins ............... ..
`240/62 R
`8/1952
`Tostevin ........................ .. 240/62 R
`
`[56]
`
`1,458,761
`1,472,141
`1,567,112
`2,606,999
`
`
`
`KOITO 103
`
` 1
`
`'
`
`Koito Manufacturing v. Adaptive Headlam
`'
`|PR2016-0007
`
`1
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`KOITO 1030
`Koito Manufacturing v. Adaptive Headlamp
`IPR2016-00079
`
`

`
`U.S. Patent May17, 1977
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`U.S. Patent May 17, 1977
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`U.S. Patent May 17, 1977
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`Sheet 4 of4
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`4,024,388
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`5
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`

`
`1
`
`CORNERING LIGHT SYSTEM FOR
`TWO-WHEELED VEHICLES
`
`4,024,388
`
`BACKGROUND OF THE INVENTION
`1. Field of the Invention
`The present invention relates to a lighting system for
`use on two-wheeled vehicles, and more particularly to
`a system including a non-rotatable headlight for mount-
`ing on the frame of a two-wheeled vehicle to enable an
`operator to see hazards lying in his path as the vehicle
`executes a cornering maneuver. Two-wheeled vehicles
`tilt toward the inside of the curve when making a cor-
`nering maneuver, thereby rendering the conventional
`headlight mounted thereon ineffective for illuminating
`the path. The cornering light system of the present
`invention includes a lamp having a rectangular beam
`mounted in such a way that its centerline is inclined to
`the horizontal plane and oriented so that the projection
`of the centerline onto the horizontal plane forms a
`predetermined angle with the vehicle longitudinal axis,
`and whose rectangular cross-section is rotated about
`the centerline of the beam to a particularly advanta-
`geous angle. In operation, the lamp is fixed to the front
`fork or to the frame of the vehicle and does not rotate
`
`with respect thereto, tilting with the vehicle as the
`vehicle tilts into the comer, and thereby being brought
`into an orientation effective for illuminating hazards
`lying ahead on a curved road.
`2. The Prior Art
`
`Much work has been done on systems for pivoting
`automobile headlamps. Unlike a two-wheeled vehicle,
`an automobile tends to roll outwards during a turn,
`rather than to tilt into the turn. As a result, systems for
`pivoting automobile headlamps must invariably direct
`the beam more and more downwards as the rotating
`headlight pivots away from its straight ahead position.
`Therefore, it is necessary to consider only the prior art
`dealing with two-wheeled vehicles.
`U.S. Pat. No. 606,974, issued July 5, 1898, and U.S.
`Pat. No. 614,733, issued Nov. 22, 1898, both to Leuc-
`kert show a compound reflecting surface for use with a
`non-electric lantern, for producing a beam pattern
`having side lobes. The lamp cannot be switched off and
`on easily, and the cross-section of the beam is not
`canted with respect to its centerline to compensate for
`tilt of the vehicle as the vehicle rounds a curve.
`U.S. Pat. No. 1,710,819, issued Apr. 30, 1929, to
`Griffin shows a headlight for an automobile which in-
`cludes two side lights angled at 45° in a horizontal plane
`from the main light. The side lights are selectively
`switched off and on by rotation of the steering wheel.
`The cornering lights are simply uncanted spherical
`beam headlights and there is no suggestion of canting
`the beam to compensate for tilt.
`A number of patents make use of headlamps which
`rotate relative to the frame of the vehicle, including
`U.S. Pat. No. 3,614,416,
`issued Oct. 19, 1971 to
`Fleury, U.S. Pat. No. 3,567,919, issued Mar. 2, 1971 to
`Alpagn and U.S. Pat. No. 3,504,171 issued Mar. 31,
`1970 to Martin. Likewise, rotating headlights for bicy-
`cles are shown by the following: U.S. Pat. No.
`2,335,676 issued Nov. 30, 1943 to Humphrey; U.S.
`Pat. No. 654,978 issued July 31, 1900 to Henry; U.S.
`Pat. No. 627,682 issued June 27, 1899 to Chapleau.
`U.S. Pat. No. 1,635,393 issued July 12, 1927 to
`Amans and U.S. Pat. No. 1,593,075 issued July 20,
`1926 to Hensley, both relate to headlights for locomo-
`
`2
`tives. They are interesting here in that they both show
`pendulous means for rotating the headlight as the loco-
`motive rounds a bend. Because the effect of centrifugal
`force on the pendulous element was not taken into
`account in the‘ design of these inventions,
`it would
`appear that their effectiveness is limited to curves on
`which the road bed is overbanked.
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`Thus, it would appear that none of the prior art dis-
`closes or suggests the canting of the beam pattern of
`the cornering lights to compensate for thetilt of a two-
`wheeled vehicle during a turn.
`SUMMARY
`
`Unlike a three- or a four-wheeled vehicle, a two-
`wheeled vehicle necessarily leans to the inside of the
`curve while turning. This condition of leaning creates a
`peculiar and severe problem for the two-wheeled vehi-
`cle regarding night-time lighting.
`.
`Part of the problem is that the road ahead of the
`two-wheeled vehicle curves out of the_ area illuminated
`by the vehicle’s main conventional headlight. This ef-
`fect is made worse by the peculiar way in which a two
`wheeled vehicle is caused to turn at high speeds. At
`high speeds turning is not accomplished by steering or
`turning the front wheel but rather by leaning. The oper-
`ator shifts his weight to which ever side he desires to
`turn, and the vehicle then executes the turn without
`any significant turning of the front wheel. Thus, the
`headlight, even if mounted on the front wheel or on the
`handle bars remains pointed in the direction of the
`longitudinal axis of the body of the vehicle. As a result,
`the light beam or the headlight does not anticipate in
`any way the direction in which the vehicle is turning; in
`fact, it tends to lag the turning of the vehicle. More-
`over, some drivers under some turning conditions find
`it advantageous to steer in a direction slightly opposite
`to the direction in which the motorcycle or bicycle is
`actually turning. This simply aggravates the illumina-
`tion problem.
`The required degree of leaning is proportional to
`both the speed of the vehicle and the sharpness of the
`turn. Unfortunately it is precisely under the conditions
`of high speed and sharp turns that the need for ade-
`quate lighting is greatest, and the performance of the
`conventional headlight is least effective.
`To compensate for the functional limitations of con-
`ventional lighting systems the present invention is di-
`rected towards a cornering light system for two-
`wheeled vehicles. The system is a preferred embodi-
`ment includes two auxiliary cornering lights plus appa-
`ratus for mounting the lights to the vehicle and appara-
`tus for controlling the operation of the lights.
`Each of the light or lamp assemblies is attached to the
`front fork or to the frame of the vehicle and does not
`rotate in any way with respect to that member. It is a
`point of novelty of the present invention, that the desir-
`able illumination pattern produced by each lamp upon
`the roadway depends entirely on the tilt of the two-
`wheeled vehicle as it rounds the curve. This is accom-
`plished by the unique beam direction and cross-section
`employed by the present invention.
`Each lamp is attached to the vehicle in such a way
`that the projection of the centerline onto the horizontal
`plane makes an angle of approximately 28° with respect
`to the forward end of the vehicle’s longitudinal axis and
`in such a way that the centerline of the beam is inclined
`above the horizontal plane at such an angle that the
`centerline becomes parallel to the ground when the
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`vehicle is leaned approximately 22° from its normally
`upright position. About this beam centerline, the cross-
`section of the beam is substantially rectangular or
`oblong with its longer axis extending outwardly from
`the vehicle and upwardly at an angle of 22°, approxi-
`mately, with respect to the horizontal. The light may
`not be switched on until the vehicle departs from up-
`right position, and as the vehicle tilts the light is’ low-
`ered toward the road surface and rotated, whereby the
`longer dimension of the rectangular crosssection be-
`comes more nearly horizontal.
`The effect of this unique beam orientation is to pro-
`vide increasingly wide angular illumination in the
`proper direction of turn for vehicle at lean ‘angles up to
`and including 30° from the vertical. Lean angles of
`greater than 30° will result in a progressive narrowing
`of the field of the illumination, but still adequate even
`at 45°, which is considered the practical maximum lean
`angle for typical two-wheeled vehicles.
`The cornering light system is preferably to operate
`only when it is actually needed. This may be accom-
`plished through manual switching means or by tilt-sen-
`sitive switching means. A manual override switch could
`also be provided for keeping both lamps on regardless
`of lean angle.
`To comply with existing legislation in some jurisdic-
`tions dimming means may also be provided. Dimming
`may be accomplished by use of a special dimming
`switch for turning off the cornering lights when their
`operation could interfere with other drivers, or it may
`be accomplished by operating the system from the
`existing high beam circuit of the vehicle headlight,
`which contains its own dimmer switch.
`Thus the present invention provides a cornering light
`system operable over a wide range of vehicle speeds
`and turning radii. The system makes use of a pair of
`headlights which do not rotate with respect to the part
`of the frame'of the vehicle to which they are mounted.
`Instead, the headlights are canted at an angle which
`compensates for the tilt of the vehicle when making a
`turn. The lights may be switched on manually, or by a
`tilt sensitive sensor. In either case, the switching on of
`the lights is independent of the rotation of the handle
`bar.
`The novel ‘features which are believed to be charac-
`teristic of the invention, both as to organization and
`method of operation, together with further objects and
`advantages thereof, will be better understood from the
`following description considered in connection with
`the accompanying drawings in which a preferred em-
`bodiment of the invention is illustrated by way of exam-
`ple. It is to be expressly understood, however, that the
`drawings are for the purpose of illustration and descrip-
`tion only and are not intended as a definition of the
`limits of the invention.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`FIG. 1 shows the lighting coverage pattern of a con-
`ventional headlight for various lean angels of the vehi-
`cle.
`'
`FIG. 2 is a front view showing the cornering light
`beam when the vehicle is tilted 10°.
`FIG. 3 is a front view showing the cornering light
`beam when the vehicle is tilted 22°.
`FIG. 4 is a front view showing the cornering light
`beam when the vehicle is tilted 35°.
`FIG. 5 is a front view showing the cornering light
`beam when the vehicle is tilted 45°.
`
`FIG. 6 is a plan view showing the area on the ground
`illuminated by the cornering light when the vehicle is
`tilted 10°.
`FIG. 7 is a plan view showing the area on the ground
`illuminated by the cornering light when the vehicle is
`tilted 22°.
`'
`FIG. 8 is a plan view showing the area on the ground
`illuminated by the cornering light when the vehicle is
`tilted 35°.
`FIG. 9 is a plan view showing the area on the ground
`illuminated by the cornering light when the vehicle is
`tilted 45°.
`FIG. 10 is an electrical circuit diagram showing how
`the tilt actuated switch is connected to the cornering
`light circuit.
`FIG. 11 is a rear view of the vehicle executing a right
`turn, showing the relationship between the effective
`“g” force vector and the tilt of the vehicle;
`FIG. 12 is a rear- view of the vehicle executing a left
`turn, showing the relationship between the effective
`“g” force vector and the tilt of the vehicle;
`FIG. 13 is a perspective view of a cornering lamp
`assembly.
`DESCRIPTION OF THE PREFERRED
`EMBODIMENT
`
`-
`
`The number of two-wheeled vehicles in this country
`has expanded dramatically in the last decade. All of the
`motorcycles and many of the bicycles are presently
`equipped with a headlight for permitting them to be
`driven at night. Sometimes the headlight is mounted on
`the body of the vehicle, while in other cases the head-
`light is mounted on a part of the vehicle, such as the
`handle bars, which is steered to produce a turn. It is
`believed that none of these multitudes of vehicles is
`equipped presently with adequate lights for cornering.
`The need for adequate cornering lights will be shown in
`the following paragraphs, and the need is a long-stand-
`ing one, which the present invention seeks to fulfill.
`A description will therefore be given of a particular
`preferred embodiment of a cornering light system for
`use with two-wheeled vehicles. The system includes not
`only its lights, but also the electrical and control appa-
`ratus for use with _the lights. The theory of the design of
`the system will be explained, and a number of non-
`obvious features willbe described.
`A two-wheeled vehicle turns in a different manner
`from a three-or four-wheeled vehicle, as will be shown
`in greater detail below. Probably the most striking dif-
`ference is that the two-wheeled vehicle tilts into the
`turn. The major reason for tilting is to permit the
`weight of the vehicle, assumed to be concentrated at a
`center of gravity, to be used to counteract centrifugal
`force acting on the vehicle in a direction towards the
`outside of the turn. The driver, through reflex action
`acquired through experience, controls the vehicle so as
`to achieve a balance between the centrifugal force
`tending to throw him towards the outside of the curve
`and the component of his weight which tends to pull
`the tilted vehicle over toward the inside of the curve
`Actually, the situation is more complicated because of
`the presence of gyroscopic forces, and other effects.
`The ‘overall result, however,
`is simply that a two-
`wheeled vehicle tilts into the turn.
`*
`The inadequacy of the conventional headlight during
`cornering of a two-wheeled vehicle is dramatically
`shown in FIG.~ 1. That Figure shows the lighting cover-
`age pattern of a conventional 7° by 35° high beam
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`headlight for various lean angles. The coverage pat-
`terns are shown as viewed from directly in front of the
`vehicle and looking horizontally. As the vehicle tilts,
`first to 10° then 22°, then 35°, etc., the headlight beam
`pattern, which nominally measures 7° vertically by 35°
`horizontally, also rotates. This in turn causes the light
`of the beam to fall on the ground at points progressively
`closer to the vehcile than desirable. It also has the
`additional undesirable effect that part of the light beam
`is elevated and thereby could become a hazard to other
`drivers. The illumination pattern produced by the con-
`ventional headlight during the tilting and cornering
`maneuver is a highly undesirable pattern. As a general
`rule, higher vehicle speeds require a greater angle of tilt
`for a given turn radius. The higher vehicle speed also
`requires an extended illumination pattern, rather than
`the reduced pattern produced by the conventional high
`beam headlight. Thus, the conventional headlight pro-
`duces a small illuminated area at the very time when an
`extended area is most desirable. It should be apparent
`that improvement in the illumination pattern is not to
`be gained from simply fitting more or brighter head-
`lights. Lack of adequate cornering illumination does
`not arise simply from an insufficient quantity of avail-
`able light, but from the inability of conventional light-
`ing equipment to place the quantity of light that is
`available where it will do the most good in cornering.
`The present invention accepts the tilting of a two-
`wheeled vehicle while cornering as a fact of life, and
`makes use of this effect to produce an illumination
`pattern that is well adapted to various vehicle speeds
`and tilt angles.
`'
`In the present invention, illumination for cornering is
`provided through the addition of special lamps 11 and
`13 of FIG. 2, associated with the right and left side
`respectively of the vehicle 15 for making right and left
`turns respectively. The utility of the present invention
`derives from the novel illumination pattern developed
`by each of these lamps. This pattern in turn is partly the
`result of the unique angle at which the beam of light
`produced by one of the lamps is pointed and partially
`by the unique cross—section of the lamp beam pattern.
`These two innovations enable the cornering light sys-
`tem to produce a highly advantageous pattern of illumi-
`nation, when mounted on the two-wheeled vehicle in
`accordance with the embodiment shown below.
`The cornering light system produces a pattern of
`illumination which automatically adapts itself for vari-
`ous vehicle speeds and turning rates, unlike the pattern
`of illumination produced by conventional headlights.
`The angle of tilt of the two-wheeled vehicle automati-
`cally and necessarily reflects both the speed of the
`vehicle and the turning rate. If a cornering light were
`mounted with its beam axis in the forward direction,
`the beam cross-section could rotate only about that
`axis as the vehicle tilts. On the other hand, if the cor-
`nering lamp were mounted with its beam centerline
`pointing to the side, at right angles to the longitudinal
`axis of the vehicle, the beam would dip but would not
`rotate about its centerline as the vehicle tilts. The cor-
`nering light system of the present invention makes use
`of lamps positioned intermediate the extreme positions
`just described, to produce a simultaneous dipping of
`the beam centerline and rotation of the beam cross-sec-
`
`tional pattern about that centerline as the vehicle tilts.
`It is the simultaneous dipping and rotating of the beam
`that produces the unique illumination pattern of the
`present invention.
`
`The precise parameters of the present invention have
`been determined empirically. It has been found advan-
`tageous to arrange for the centerline of the beam of
`each lamp to be positioned so that the projection of the
`centerline onto the horizontal plane makes an angle of
`approximately 28° with respect to the forward end of
`the vehicle’s longitudinal axis and so that the centerline
`of the beam is inclined above the horizontal plane at
`such an angle that the centerline becomes parallel to
`the ground when the vehicle is leaned approximately
`22° from its normally upright position. Likewise it has
`been found advantageous to provide a beam having
`rectangular cross-section measuring approximately 15°
`by 45° whose longer dimension is inclined upward away
`from the vehicle at an angle of approximately 22° with
`respect to the horizontal plane. It can readily be appre-
`ciated, that these numbers can be only approximate,
`because they are based partially on the.preferences of
`individual drivers and on the concept of providing the
`best illumination for the type of turn which occurs most
`frequently. Obviously,
`the angles mentioned above
`could be adjusted for non-typical types of driving, such
`as racing.
`FIGS. 2, 3, 4 and 5 show the two-wheeled vehicle 80
`in a front view for successive tilt angles of 10°, 22°, 35°
`and 45°. In these figures it is assumed that the cornering
`light produces a beam having a well defined cross-sec-
`tion and that the beam is substantially uniformly bright
`at all points across it. The right top edge of the beam is
`indicated by 84. The angle between these edges of the
`beam appear to be much greater than its actual value of
`15° because of foreshortening. Numerals 85, 86 and 87
`indicate the forward projection of the intersection of
`the beam with a vertical cylindricalgsurface located a
`constant distance of 25 feet from the cornering lamp.
`As the two-wheeled vehicle 80 tilts from 10° to 22° with
`respect to the vertical, the beam is seen to be lowered
`into a more advantageous position for illuminating the
`area into which the vehicle is turning. The maximum
`coverage occurs for tilt angles on the order of 22°,
`which is believed to be the most common tilt angle
`generally encountered. As the tilt angle further in-
`creases beyond 22°, FIGS. 4 and 5 show that the cover-
`age gradually is reduced as the top of the beam 86 is
`rotated to positions where it strikes the ground closer
`to the two-wheeled vehicle. Even at a tilt angle as large
`as 45° as shown in FIG. 5, which is the largest practical
`tilt angle likely to be encountered, the lateral coverage
`of the cornering light is still excellent.
`FIGS. 6, 7, 8 and 9 are plan views showing the area
`on the ground which is illuminated by the cornering
`light for successive tilt angles of 10°, 22°, 35° and 45°.
`In these figures, the shaded area indicates the area on
`the ground which is illuminated. These figures show the
`advantageous manner in which the pattern on the
`ground is extended in the direction of the turn as the
`speed and sharpness of the turn increase up to 22° or
`more of tilt angle. Even for a tilt angle of 35° as shown
`in FIG. 8, the lateral coverage is excellent. Beyond 35°
`of tilt the pattern is diminished somewhat although still
`adequate even-at 45° tilt as shown in FIG. 9.
`The external appearance of one of the light assem-
`blies is shown in FIG, 13 for a preferred embodiment.
`The light is emitted through a lens at the front end 102
`of the assembly. The enclosure 104 has grooves in its
`surface, of which groove 106 is typical. An aligning
`block 108 is inserted into one of the grooves and at-
`tached therein. This aligning block 108 has a clamping
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`surface cut into it at an angle to assure that the assem-
`bly will be pointed in the proper direction when the
`clamping surface is attached to a horizontal laterally
`directed member 101 which is mounted on the vehicle.
`A different shaped aligning block would be used if the
`lamp is to be mounted to a longitudinally or to a verti-
`cally directed member. A clamp 112 is provided to
`secure the aligning block to the lateral member, and
`the clamp 112 is held in place by a screw 114. A resil-
`ient liner 116 may be provided to prevent sliding and to
`prevent marring of the lateral member 110. This
`mounting method is used to attach the light assembly to
`a horizontal laterally directed bar or tube.
`Provided the central direction of the beam of each
`cornering lamp is maintained at the proper angle, the
`lamps may be affixed to the vehicle in any position
`consistent with applicable law. Possible mounting loca-
`tions include:
`a. above, below, or to the sides of an existing head-
`light
`b. to the same mounts as are used for existing turn
`signals
`c. to the handlebars of the vehicle
`d. to the front suspension or fork of the vehicle
`e. to a fairing
`f. to the frame of the vehicle
`
`g. to the front roll bars of the vehicle.
`It is obvious that an appropriate connecting structure
`would be required for each of these possible mounting
`locations, and it is obvious that some form of universal
`connecting structure, such as a ball joint with locking
`means, might be employed.
`A furthe.r and most useful part of the present inven-
`tion is the tilt sensitive switch 17 of FIG. 2 which can be
`arranged to turn on an appropriate cornering light only
`when the vehicle is leaning at an angle of approxi-
`mately 10°. Thus, even at night, the cornering lights are
`not on all the time, but are switched on automatically
`only when the vehicle is leaning into a turn.
`Thus,
`the combination of carefully devised beam
`configuration and fully. automatic operation produced
`by the tilt actuated switch, ensures that the cornering
`light system will provide near-optimum lighting cover-
`age on a demand basis for almost every cornering situa-
`tion:
`Less that 10° Lean Angle — Vehicle is either not
`turning, or turning very gradually, or at very low
`speed. Cornering light not needed, not on.
`10° Lean Angle — Typically gradual Freeway curve.
`Cornering light is on. Road contact pattefn is nar-
`row and forward. (See FIGS. 2 and 6.)
`22° Lean Angle — Normal brisk canyon or mountain
`road riding. Cornering light is on. Beam is parallel
`with roadway and road contact pattern is at maxi-
`mum. (See FIGS. 3 and 7.) AN ESTIMATED 80%
`OF ALL MOTORCYCLE CORNERING IS DONE
`AT LEAN ANGLES OF 22° OR LESS.
`35° Lean Angle — Sharp low-speed turn on very high
`speed gradual
`turn. Cornering light is on. Beam
`road Contact pattern is reduced somewhat from
`22°, but still more than adequate, i.e., roughly three
`traffic lanes wide at 25 feet. (See FIGS. 4 and 8.)
`45° Lean Angle — Road racing conditions: either
`very sharp tum at medium speed or gradual turn at
`VERY high speed. A very sharp turn means that
`close-in coverage will be required. For a high-
`speed gradual turn little additional width of cover-
`age is required, but must must be done to over-
`
`4,024,388
`
`8
`In
`come lateral beam obscurance of headlight.
`either case, the road contact pattern of the pro-
`posed motorcycle cornering light is nearly ideal.
`(See FIGS. 5 and 9.)
`The electrical system of the cornering light system
`includes several novel optional features. The system
`can be wired into the high beam circuit of the vehicle to
`which it
`is mounted. Thus, dimming or dipping the
`headlight beam for oncoming traffic will switch off the
`cornering lights at their source and ensure that, regard-
`less of the vehicle’s lean angle, the cornering lights will
`not come on and, therefore, cannot dazzle other driv-
`ers. A manual on-offlswitch can be provided to enable
`the system such as shown at 31. Once that switch is
`turned on, the operation of the system will be con-
`trolled by an acceleration or tilt activated switch, which
`automatically turns on the appropriate cornering light
`in response to “g ” forces or tilting of the vehicle as it
`makes a turn.
`
`Left and right manual override switches could also be
`provided, as at 33 and 35, to keep either or both lights
`on regardless of lean angle.
`FIG. 10 is an electrical diagram showing the inter-
`connection of the left and right cornering lamps 22 and
`24 respectively,‘ with the tilt sensing switch 26 through
`a tenninal board 28. One lead from each of the lamps
`22 and 24 is attached to a common terminal 30 which
`is supplied with current from a suitable power supply
`through a manual “off-on” switch 31. That power sup-
`ply might alternatively be a battery, a generator or
`alternator, or the high beam headlight circuit of the
`vehicle.
`
`is required that auxiliary lamps
`In some States it
`mounted on a vehicle must not cause a glaring light
`projected into the eyes of an approaching driver. Sup-
`plying the current from the high beam headlight circuit
`of the vehicle ensures that the cornering lights cannot
`dazzle approaching drivers because dipping the head-
`light for oncoming traffic will switch off the cornering
`lights at their source. The other lead from each lamp is
`connected to a terminal of the tilt actuated switch 26
`through appropriate terminals 32 and 34 on the termi-
`nal board 28. The common terminal 38 of the tilt actu-
`ated switch 26 is _connected to terminal 36 on the ter-
`minal board. Terminal 36 is also connected to the chas-
`sis. The lamps 22 and 24 are connected to leads run-
`ning to the terminal board 28 through bullet connec-
`tors of which 44 is typical. The U-shaped mercury tube
`26 is affixed to the vehicle in an upright position and in
`a plane generally normal to the longitudinal axis of the
`vehicle.
`FIG. 10 shows a single pole double throw tilt actu-
`ated switch 26. It is obvious that other types of tilt
`actuated switch could be used in place of one illus-
`trated. For example,
`two single pole single throw
`switches could be used in place of the single pole dou-
`ble throw switch illustrated, and the position of the
`electrodes within the switch can be chosen to suit the
`specific mounting angle in a particular application. The
`mercury switch 26 would have to be evacuated if con-
`structed as shown to avoid the effects of the pressure of
`the gas which would otherwise be confined between the
`ends of the mercury columns and the ends of the U-
`tube. An alternative embodiment avoids this problem
`and the necessity for evacuating the U-tube by includ-
`ing a pressure equalizing tube 41 of FIG. 10 which
`permits the confined gas volumes in the ends of the
`U-tube to communicate with each other. Further, the
`
`5
`
`l0
`
`I5
`
`20
`
`25
`
`30
`
`35
`
`40
`
`45
`
`50
`
`55
`
`60
`
`65
`
`9
`
`

`
`_‘ 4%.
`
`9
`
`4,024,388
`
`mercury switch of FIG. 10 could be replaced by a
`manually-operated turn-signal type of SPDT switch.
`Finally, a vertical gyro could be used to give a true
`vertical reference from which tilt angles could be mea-
`sured for use in actuating the switches which control
`the operation of the turning lamps.
`It is by no means obvious that a mercury or similar
`acceleration sensitive switch can be used to regulate
`the operation of the cornering lamps for use on a two-
`wheeled vehicle. The effective acceleration vector is
`defined as the resultant of the weight vector and the
`centrifugal force vector and it represents the effective
`gravity or “g” force acting upon the vehicle. At first
`glance, it might appear that the vehicle would tilt, when
`rounding the comer, to an angle aligned with the effec-
`tive acceleration vector. If this were the case, an accler-
`ation activated switch would not be effective. For ex-
`ample, the length of the mercury columns in U-tube
`would reach a balanced position relative to the enclos-
`ing U-tube. In that position, the configuration of the
`mercury columns within the enclousure would be iden-
`tical to the configuration reached with the U-tube in
`the untilted attitude and with the vehicle stationary.
`Thus, it is by no means obvious how an acceleration
`sensitive switch can operate in the present invention to
`sense the angle of tilt.
`Nevertheless, after much testing, it has been discov-
`ered by the present inventor that a U-tube mercury
`switch can indeed be used in the described manner to
`sense the tilt. This is an unanticipated and surprising
`discovery and no proven theory has yet been developed
`to account for the phenomenon.
`'
`It has been proposed by the present inventor that the
`observed operation of the mercury switches can be
`accounted for by the following statement of theory of
`operation: A two-wheeled vehicle is caused to turn by
`the operator shifting his weight to one side or the other.
`A turn could be initiated even if the steering mecha-
`nism and handleb