US3233095A

US3233095A - Electric lamps

Info

Publication number: US3233095A
Application number: US301550A
Authority: US
Inventors: Caine Frank Alexander
Original assignee: Humber Ltd
Current assignee: Humber Ltd
Priority date: 1962-08-15
Filing date: 1963-08-12
Publication date: 1966-02-01
Anticipated expiration: 1983-02-01
Also published as: GB1019343A

Description

Feb. 1, 1966 F. A. CAINE 3,233,095

ELECTRIC LAMPS Filed Aug. 12. 1963 United States Patert O 3,233,095 ELECTRIC LAlVlPS Frank Alexander Caine, Coventry, England, assignor to Humber Limited, Coventry, England, a British company Filed Aug. 12, 1963, Ser. No. 301,550 Claims priority, application Great Britain, Aug. 15, 1962, 31,359/62 4 Claims. (CI. %RO-46.03)

The invention relates to electric lamps of the kind having a lamp bulb held in housing having an aperture covered by a transparent or translucent member. Such lamps are used, for example, as indicator lamps on motor vehicles to give a visual indication of the functioning of various devices such as headlamps, direction indicators, and overdrive, although the invention is not restricted in its application to such indicator lamps. When lamps of this kind are required to be used both in daylight and at night it is sometimes found that a lamp brilliance, as seen through the transparent or translucent member, which is suitable for use in daylight or other conditions of bright general lighting is too bright in the dark. It is an object of the invention to provide a particularly simple means by which the brilliance may be changed.

The invention provides a lamp of the above kind which has the characteristic feature that the transparent or translucent member is adjustable by rotation about an aXis substantially perpendicular to the principal light rays passing through the member from the bulb and has different degrees of light transmission of the rays in different positions of rotation.

The Construction may be such that in one position of adjustment of the member the light is cut off substantially completely or that in all positions of adjustment an effective amount of light is transmitted through the member.

In one form of the inv ntion the member, which may be a plastic moulding, is generally spherical, is mounted for rotation as aforesaid about a diameter and has, perpendicular to that diameter, a diametrical light passageway of higher transmissivity than the remainder of the equatorial zone of the sphere. The passageway may be a hole which may be open at both ends or closed at one or each end by a thin layer of light transmitting material or it may be a plug of material having greater light transmission than the body of the member (eg. the body may be coloured or translucent and the plug clear and transparent). In another form the light passageway is provided by treatment of the surface of the member (eg. by roughening or colouring) to reduce the light transmission while leaving diametrically opposed clear areas.

In another form of the invention the member is generally cylindrical and mounted for rotation about its axis. There is a diametrical light passageway, as aforesaid, perpendicular to the aXis. When there are two or more lamps side by side, there may be a single cylindrical member common to the several lamps, the member having individual passageways for the several lamps and being divided by opaque separators into sections appropriate to the individual lamps. The passageways may be of circular cross-section or elongated in the axial direction.

To support the member for rotation it may have (eg. moulded on it) two spigots which work in bearings in the housing or it may have two sockets in which pivot pins or spigots in the housing are received.

The member may have a projection from its curved surface which protrudes from the housing and provides a finger piece by which the member may be rotated as aforesaid.

In the case of a single lamp having `a spherical member, the housing may be of tubular form with two diametrically opposed notches cut in one end in which spigots on a spherical lens member are received, the member being held in place by a bezel spun over the member and a lip around the tube. In the case of a row of lamps, they may each be held in a square section housing and a single cylindrical lens member may extend along the row and be supported at the ends in the end housings. A bezel may hold the member in place.

The cylindrical form of lens member may be used when there is only one lamp. The nger piece may be a local projection or spigot or it may be a rib extendng along the whole length of a cylinder or around a substantial arc of a sphere. The change from full brilliance to minimum briiliance may be made to be progressive with rotation of the lens member. For this purpose the member may be modified in shape or light transmissability.

Two specific embodiments of the invention will now be described by way of example and with reference to the accompanying drawings, in which FIGURE 1 is a side view of a lamp body,

FIGURE 2 is a section on the line 2-2 in FIGURE l, and

FIGURE 3 is a section of the first embodiment on the line 3 3 in FIGURE 1, and

FIGURE 4 is a view corresponding to FIGURE 3 of an alternative embodiment.

The lamp shown in FIGURES l, 2 and 3 has a cylindrical tubular body 10, moulded in a plastic or similar material, open at one end, and closed at the other by a translucent cylinder 11, which rests adjacent a complementary wall 12, moulded near the said other end and having a slot 14 for the passage of light.

The cylinder 11 rotates in spigots 16 in bearings 18 and is held in place by a bezel 19 spun over it and around a lip 20.

A slot 22 within the cylinder leaves a narrow wall 23 through which light passes more readily than through the entire thickness of the cylinder. Thus, by rotating the cylinder about its spigots, the size of the aperture leading directly to this thin wall 23 is varied and consequently the proportion of light transmitted thereby is varied.

A projection 30 provides a finger piece for which the cylinder can be rotated as desired.

The embodiment shown in FIGURES 1, 2, and 4 is the same as the embodiment of FIGURES l to 3 except that the housing 10 comprises four tubular holes in parallel side-by-side relation and there is a single translucent cylinder 11 extending across the open mouths of the holes. The cylinder has a slot 22 for each hole and there are opaque separators 43 to divide the cylinder into four portions correspon ding to the four holes or lamps. There is a single bezel 19 to retain the cylinder -in the housing.

I claim:

1. An electric lamp comprising a lamp bulb, an opaque housing containing the bulb and having an aperture through which light from the bulb may be emitted and a light-transmitting translucent cover member for the aperture, means to mount the cover member in the housing for rotation about an axis transverse to the rincipal light rays passing through the aperture from the bulb which cover member is circular in cross-section in planes perpendicular to the said axis and has a diametrical light passageway of lower light absorption than the remainder of the member.

2. A plurality of electric lamps side-by-side each comprising a lamp bulb, a housing containing the bulbs and having a plurality of apertures in parallel side-by-sde relation through which light from the bulbs respectively, may be emitted, there being for all the lamps a single cylindrical translucent light transmitting cover member for the apertures, means to mount the cover member in the housing tor rotation about the axs of the cylinder with the said axis extending along the housing transverse to the principal light rays passing through the apertures from the bulbs, there being for each lamp a diametrical light passageway in the cover member of lower light absorption than the remainder of the cover member, which has opaque separators to divide the cover member into sections appropriate to the individual lamps.

3. An electric lamp comprising a lamp bulb, an opaque tubular housing containing the bulb and having an opening at one end through which light from the bulb may be emitted, a light-transmitting translucent cover member for the aperture, said cover member being of cylindrical form With its axis perpendicular to the axis of the tubular housing, having axial spigots projecting from the ends of the cylinder and supported in bearings in the housing, the cover member closing the end opening of the housing, and said cover member having a diametrical socket which is open at one end and closed at the other, and in one position of rotation is aligned With the throughway of the tube and a bezel around the tube mouth and having an aperture fitting over and smaller than the diameter of the cylinder to hold the cylinder within the housing.

4. A plurality of electric lamps each comprising a lamp bulb, an opaque housing having a plurality of tubular holes in parailel side-by-side r-elation containing the bulbs respectively and having openings at one end through which light from the bulbs may be emitted, and there being for all the lamps a single lght-transmitting translucent cover member for the apertures, said cover member being of cylindrical form with 'its axis perpendicular to and intersecting the aXes of the tubular holes, having spigots projecting axially from the ends of hte cylinder and sup- Ported in bearings in the housing, the cover member closing the said end openings of the holes, and said cover member having for each lamp a diametrical socket which is open at one end and closed at the other and, in one position of rotation is aligncd with the hole and opaque separators to divide the cover member into sections appropriate to the individual lamps and a bezel around the housing and having an aperture tting over and smaller than the diameter of the cylinder to hold the cyl'inder within the housing.

References Cite by the Examiner UNITED STATES PATENTS 2,474,677 6/1949 Kirkland 240 46.03 X 2,783,365 2/1957 =Wilfert 240-46.03 X 2,998,597 8/1961 Edwards. 3,l19,566 1/1964 Close ?AO-46.03

NORTON ANSHER, Pr'mary Examine r.

C. R. RHODES, Assistant Examiner.

Claims

1. AN ELECTRIC LAMP COMPRISING A LAMP BULB, AN OPAQUE HOUSING CONTAINING THE BULB AND HAVING AN APERTURE THROUGH WHICH LIGHT FROM THE BULB MAY BE EMITTED AND A LIGHT-TRANSMITTING TRANSLUCENT COVER MEMBER FOR THE APER-G TURE, MEANS TO MOUNT THE COVER MEMBER IN THE HOUSING FOR ROTATION ABOUT AN AXIS TRANSVERSE TO THE PRINCIPAL LIGHT RAYS PASSING THROUGH THE APERTURE FROM THE BULB WHICH COVER MEMBR IS CIRCULAR IN CROSS-SECTION IN PLANES PERPENDICULAR TO THE SAID AXIS AND HAS A DIAMETRICAL LIGHT PASSAGEAWAY OF LOWER LIGHT ABSORPTION THAN THE REMAINDER OF THE MEMBER.