US2021563A - Head lamp - Google Patents

Description

Nov. 19, 1935. MELlsH 2,021,563

HEADLAMP Filed OQL 25, 1 955 ATTORNEYS Patented Nov. 19, 1935 UNITED STATES PATENT OFFICE 1 Claim.

This invention relates to improvements in headlights, particularly for automobiles, and primarily to the control of direction in which the light beam is reflected.

An object of the invention is to provide the reflector of a headlight with a lamp bulb movable'on an axis or center in relation to the focal axis of the reflector for selectively shifting the filament of the lamp to different positions or sides in off-set relation to the focal axis of the reflector for reflecting a beam of light in an angular direction and changing or alternating from one directionto another.

Other objects and further advantages of the invention are more fully set forth in a description of the accompanying drawing, in which:

Figure 1 is a central vertical section through a rear portion of a head lamp of an automobile, containing the means for rotatively shifting a 2t double filament lamp bulb for changing the reflection or direction of the light beam.

Figure 2 is a front elevation of the front end of the lamp bulb within a reflector, shown with the filaments positioned for either up or down 25 direction of light reflection.

Figure 3 is a similar view for sidewise direction.

Figure 4 is a section on line 44, Figure 1, including electro-mechanical means for rotating 30 the lamp socket.

It is a recognized practice for automobile headlamps to employ double filament electric light bulbs with the circuit control therefor either separate or joint, and for one type of service, a double filament lamp with the filaments of approximately the same watt rating and disposed in a parallel relation equi-distant at opposite sides. of the. axis of the bulb is provided. This type oflamp when equipped with the standard bayonet base and mounted within the lamp socket in the headlamp, normally positions the filaments horizontally at relatively opposite sides, upper and lower, of the focal axis of the reflector of the headlamp. With a separate elec- 45 tric circuit control for each filament, when the upper filament is energized, the rays of light will be deflected downwardly to below level of vision of the occupants of an approaching car and at the same time increase the illumination in front 50 of the car. Alternately when the lower filament is only energized the rays of light will be deflected upwardly.

correspondingly with the parabolic type of reflector used in most automobile headlamps an 55 adjustment of a double filament lamp as above referred to' to bring the filaments at an angle to the horizontal will produce a sidewise illumination. For'exam'ple, with the filaments in a vertical position, relatively at opposite sides of the focal axis of" the reflector, designated as right 5 and left, with the left filament energized, the rays of light will be deflected to the right for an illumination toward and across the right edge of the roadway in a right side direction of highway travel. An alternate result is produced by the 10 right filament, that is, the rays of light are reflected to the left.

The present invention contemplates the use of the commercial double filament electric lamp bulb above referred to, in a holder or socket l5 rotatable or oscillatable within the reflector of a headlamp for shifting or axially turning the electric lamp bulb to bring the filaments in selected positions forchanging the angle of reflection for appropriate directions of illumination or inclination of the beam of light without disturbing the focal setting of the lamp bulb longitudinally of the axis of therefiector.

Referring" to the drawing, l indicates the rear portion of a headlamp casing, 2, a reflector therein,.the' reflector being of a parabolic type as used in most headlamps. Both casing and reflector are relatively rigid and the rear of the reflector has a sleeve bracket 3 fixed thereon. The sleeve bracket 3' concentrically supports a lamp socket holder sleeve 4 axially or longitudinally slidable within the sleeve bracket and held against rotation by a pin 5 extending laterally from the holder sleeve and into a longitudinal slot 6 in the bracket sleeve.

The lamp socket holder sleeve 4 has an arm 1 extending upwardly therefrom engaged by an adjusting screw 8' projecting inwardly from the headlamp casing and rotatable therein for making the focusing adjustments of the electric lamp bulb 9. A coil spring l0 about the adjusting screw 8 is interposed between the inner side of the headlamp casing and the arm I for applying a pressure against the arm. By turning the screw 8 the lamp holder can be adjusted forward and backward along the central line or axis of the reflector for a proper focal position of the lamp in relation to the reflector. Various means for making a focusing adjustment may be employed, the type and detail of construction thereof being subsidiary to the present invention, the form disclosed, however, being very simple and cheap in construction.

A lamp socket II is rotatively concentrically d sposed within the tube or holder 4 and confined against longitudinal motion or displacement by collars l2 and 13 respectively on the opposite ends of the lamp socket II. The lamp or bulb socket is of a conventional type for a bayonet lamp base and circuit connector plug connection and for a double contact lamp base. As shown in Figure 1 of the drawing, the connector plug l4 engaged or socketed into the rear end of the bulb socket II is of sectional rotatable type to avoid any twisting or injury to the electric conductor wires or feed cable 15.

The collar !3 upon the rear end of the bulb socket H may be of any form for making a transmitting connection with mechanism for operating'or actuating the bulb socket and for any particular type of mechanical or electrical shifting method or mechanism, preferably for a remote actuating or operating control as by means of a button or other instrumentality on the instrument board of the automobile.

In Figure 4 of the drawing an electric mechanical means for remote operating control for rotating the lamp bulb is disclosed consisting of an electric magnet i6 suitably rigidly mounted within the headlamp casing and between the casing and the reflector. The magnet actuates a lever l1 pivotally mounted upon a bracket 18 fixed upon the inner side of the headlamp casing. The upper end of the lever I! is bifurcated for slidably connecting with a pin 19 extending laterally from an arm or lug 20 of the collar l2. The lever l1 oscillates or swings between adjustable stops or screws 2! carried by the bracket M3 for limiting the stroke of the lever and lamp bulb rotation and in the present instance to a quarter turn.

A spring 22 is fixed to the lever IT for automatically moving the lever to a normal position when the magnet is deenergized. In the preferred arrangement the lamp bulb and shifting device therefor are positioned to normally present the lamp filaments in horizontal planes for either upward or downward reflection of the beam of light and by means of the shifting mechanism the bulb and its socket are rotated to transpose the positions of the filaments from the horizontal to any angle thereto or vertical for a sidewise reflection of the beam of light. It should be recognized however that the normal position of the filaments may be reversed depending principally upon which of the angular reflections of light beam is more generally used to avoid undue shifting.

As the electric circuit and control for a double filament lamp is as now generally employed, a circuit diagram thereof need not necessarily be illustrated and described, mainly constituting two Wires or leads connecting with the lamp socket from the switches, the filaments of the lamp each having a pole connecting with a respective contact or terminal in the lamp base and the opposite pole of the filaments connecting common to ground with the base shell of the lamp.

To produce the particular angular direction of light beam reflection, it is understood that a proper design of headlamp reflector is employed and focusing adjustment or setting of the lamp bulb properly made in relation to the reflector.

By rotatively mounting the lamp bulb axially of the reflector and non-disturbing to the f0- cusing adjustments multi-directions of light beam reflection in selected angular directions from a single filament offset from the focusing axis can be obtained and this results whether the lamp bulb is of single or double filament type with the filaments offset from the focal axis of the reflector. In the employment of a double filament lamp the shifting or rotative motion of the lamp is confined to a minimum for the four major angular light beam reflection directions most needed for automobile headlight service.

When shifting the bulb the circuit to the filaments is not and need not be broken. This in many instances is of decided advantage for with the filament continuously energized in its are 25 of movement from one position to a second, there is no break of light beam in changing its direction. There is no darkening or cutting out of the light to afiect the vision of the driver of an approaching car. Thus, assuming that a fil- 50 ament in pos'tion for an upwardly reflecting light beam, the driver can shift to direct the beam to the ri ht without a break in the light.

Having described my invention, I claim:

In a headlamp, a reflector of parabolic type, a lamp socket holder mounted upon the rear side of the reflector coaxially with the focal axis of the reflector and provided for supporting a light bulb projected within the reflector, means for adjusting said holder longitudinally of the focal 4o axis of the reflector, a light bulb socket rotatively mounted within said holder and confined against longitudinal displacement, a light bulb engaged within one end of said socket and within the reflector, the bulb having double filaments in planes at relative opposite sides of the focal axis of the reflector and capable of being jointly and severally energized, severally occupying a position off-set from the focal axis of the reflector for respectively reflecting a light beam in a definite angular direction, whereupon on rotating the socket changing the plane of the filaments the direction of angular light beam reflection is changed, a collar fixed upon said socket having a radially extended arm, and a magnet having a swinging armature lever connecting With the arm of said collar for rotating said socket in one of alternate directions for adjusting the filaments from one plane to a relatively angular plane.

THOMAS G. MELISH.

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