US 3876877 A
Description (OCR text may contain errors)
[ Apr. 8, 1975 1 1 ADJUSTING DEVICE 3365.699 1/1968 Foster................t......... 3,436,555 4/1969 x 37 22 an O0 55 22 Foster 12/1969 Cronin....
Inventors: Petrus Johannes Wilhelmus 3,483,389 3.535.537 /1970 Powell Primary E.\'aminerJames W. Lawrence Assistant Examiner-T. N. Grigsby  Asslgneel f Corporation New Attorney, Agent, or FirmFrank R. Trifari  Filed: Aug. 15, 1973 ABSTRACT 211 Appl. No.: 388,341
 Foreign Application Priority Data The invention relates to a device for the relative adjustment of an envelope and a cap of a filament lamp 7211841 by means of an optical system with which a reproduction of the fi Aug. 31, 1972 Netherlands.......................
lament of the lamp is projected on photoelectric cells. According to the invention the optical system comprises a number of bundles of light con- .9 R 2 2 2 0 5 2 L C SH U n 5 .1
ductors which with their one end communicate with m7 2 32 8 5 H Q l3 2 2 %2 2 GB .9% M2 e mm Mh Gm a e S f 0 M .w F l .o o
the photoelectric cells and with their other end de- 250/223 B bouch into a screen on which the filament is reproduced.
2 Claims, 3 Drawing Figures 2.315.287 Holloway........................ 250/223X ADJUSTING DEVICE The invention relates to a device for the relative adjustment ofenvelope and cap of filament lamps before said cap and envelope are secured together, said device comprising at least one optical system by means of which the filament arranged inside the envelope is reproduced on a number of photoelectric cells which are connected electrically to a control mechanism by means of which holders for cap and envelope present in the device are movable. Such a device is known.
Until now, said known device could not be used for adjusting envelope and cap of very small filament lamps, so-called miniature filament lamps. This may be explained as follows.
The reproduction of the filament projected on the photoelectric cells should be so sharp that the photoeletric cells are activated onlyby said reproduction. In the case of a dim reproduction of the filament and the use of photoelectric cells which are sensitive to said dim reproduction, the danger actually exists that as a result of impurities which occur in the envelope material and which, of course, are also reproduced, the photoelectric cells are also activated which results in a defective adjustment by the control mechanism.
It generally holds that according as the reproduction is smaller it will also be sharper. In aligning miniature lamps the filament of which has a diameter of between 100 u and 300 ,u, the reproduction to obtain the required definition will therefore have to be very small. However, the photoelectric cells which record and possibly correct the position of the filament with reference to said small reproduction will also have to be very small.
Moreover, the wall parts of said photoelectric cells through which the light enters the photoelectric cell will have to be so large that in two juxtaposed photo electric cells a very small region is formed between the relevant wall parts which is insensitive to light signals. Photoelectric cells which satisfy said requirements are not available in trade.
It is the object of the invention to provide a device with which it is possible to adjust the envelope and cap of a very small filament lamp relative to each other.
For that purpose, the device is characterized in that a number-of bundles of light conductors are present which each communicate with their one end with a photoelectric cell, the oppositely located ends of the bundles debouching beside each other into a screen on which the filament is reproduced.
By means of the light conductors, the light impinging on the said screen is guided to the wall parts of the photoelectric cells which are sensitive to light signals.
A favorable embodiment of the device according to the invention is characterized in that each bundle, at the area where it debouches into the screen, has a striplike cross-section, the length direction of each strip extending at least approximately parallel to the line which joins the centres of the envelope and the cap. The reason for said strip-like subdivision of the screen is the following. The envelope of most filament lamps, of which the filament should occupy an accurate position relative to the lamp cap, shows a rotationally symmetric shape, the axis of symmetry lying in the plane in which the filament extends. In a mechanized manufacture of the filament lamp it has been found difficult in practice to each time clamp and the envelope in the holder in such manner that the plane in which the filament extends each time occupies the same position relative to the screen. So it may occur that upon aligning a series of lamps having a filament which has the shape of a U, a U-shaped reproduction is projected on the screen in one case, whereas in the other case the reproduction of the filament is in the form of a line. In this latter case, however, at least one photoelectric cell should always be activated by the reproduction. To enable this, the form and the position of each strip is adapted to the shape and position of said strip-like reproduction. Therefore, dimensions of the width of each strip should preferably be equal to or smaller than the diameter of the filament. As a result of this it is achieved that of at least one strip at least half of the strip surface is covered by the reproduction of the filament. ls has proved in practice that this is sufficient to activate the associated photoelectric cell.
The invention will be described in greater detail with reference to the drawing, in which FIG. 1 shows diagrammatically an embodiment of the device according to the invention and FIG. 2 and FIG. 3 show the shape and arrangement of the bundles of light conductors respectively in sectional views taken through a horizontal plane and a vertical plane.
As shown in FIG. 1, the cap 1 and envelope 2 to be adjusted relative to each other are each clamped in holders 3 and 4, respectively. The filament 5 is stretched inside the envelope 2 of a transparent material and shows an approximately U-shape. In this embodiment the holder 3 is rigidly secured whereas the holder 4 is movable. The device furthermore comprises two optical systems which are denoted by 6 and 7 and the optical axes of which encloses an angle of approximately The filament is reproduced on screens 10 and 11, respectively, with each optical system constituted by a light source 8 and a lens 9. Each screen is formed on the front of a body 12 and 13 which is normally made ofa synthetic material in which bundles of light conductors 14 are embedded. Each bundle 14 communicates on the rear side of the body in which it is embedded with a photoelectric cell 15. Each photoelectric cell is electrically connected to a control mechanism not shown by means of which the movement of the holder 4 and hence also of the envelope 5 is controlled.
As shown in FIG. 2, the cross-section of each bundle of light conductors at the area of the screen 10 or 11 has a strip-like shape 18 and at the area of the rear side of the synthetic body a shape which corresponds to the shape of the light inlet aperture of the photoelectric cell 15.
In the position of the filament 5 shown in FIG. 1, said filament is reproduced on the screen 11 as a U-shaped shadow 16, while the reproduction on the screen 11 is in the form of a line (17). The width of the strips 18 is equal to the diameter of the filament 5 so that the reproduction 17 covers at least half of a strip. As a result of this, signalling of the reproduction by at least one photoelectric cell is ensured.
When the envelope is aligned relative to the cap, both parts are secured together, for example, by means of cement.
In the embodiment shown the diameter of the filament is 148 [L and the diameter of the envelope is l lmms.
What is claimed is:
l. A device for the relative adjustment of envelope and cap of filament lamps before said cap and envelope are secured together, said device comprising at least one optical system by means of which the filament arranged inside the envelope is reproduced on a number of photoelectric cells are connected electrically to a control mechanism by means of which holders for cap and envelope present in the device are movable, wherein a number of bundles of elongated light conductors each of which communicate with at one end with a photoelectric cell, the oppositely located ends of the conductors debouching beside each other into a screen on which the filament is reproduced, each conerally right angles thereto.