Electric lamp and discharge devices: systems – Discharge device and/or rectifier in the supply circuit – Flashers
Utility Patent
1998-06-18
2001-01-02
Wong, Don (Department: 2821)
Electric lamp and discharge devices: systems
Discharge device and/or rectifier in the supply circuit
Flashers
C315S178000, C315S307000, C315S312000, C362S218000, C362S109000
Utility Patent
active
06169373
ABSTRACT:
BACKGROUND OF THE INVENTION
The invention relates to a rodlike work light, with a rodlike bulb for the main circuit connection; a cylindrical, at least partly transparent housing surrounding the rodlike bulb; an electrical connection cable connected to the rodlike bulb; and a hangar hook.
Rodlike work lights of this kind with wide-area illumination of the work field (see for instance German Utility Model DE-U 77 06 075) are used in great numbers for instance in motor vehicle repair work, and installation work in buildings, etc., where a sufficiently bright, uniform lighting of a large area is important. Typically, the rodlike bulbs used in them are fluorescent tubes, which provide the requisite light yield or brightness for the mechanical or monitoring work. For the sake of positional fixation and for reasons of manipulation, these work lights are often provided with hangar hooks from which they are hung up.
The work lights are intended for main circuit connection, because the work typically lasts relatively long and battery consumption entails environmental problems and is expensive. The need to recharge excessively often argues against the use of a rechargeable battery.
In installation and mechanical work such as that mentioned above, broad illumination of the work area is indeed indispensable. Often, such illumination is inadequate. In tight places where it is hard to see, the glare produced by such rodlike bulbs is a hindrance, yet direct illumination of a selective work field in this case is inadequate. For illuminating such a selective, narrow work field, a narrow-beam light source is needed as well. Until now, in such cases, mechanics have used a flashlight. But first, they must have one available, and second, using a flashlight means they cannot work with both hands.
Lights that use combinations of light sources are already known as well. These are battery-operated lights meant to be carried in motor vehicles, which in a first switching position function as a suitably colored blinking warning light. In a second switching position, they function as a handheld light, or a light on a stand, with a white-light source. Because of their size, they can hardly be used for the aforementioned purpose as a work light. The disadvantages of using batteries for this purpose have already been noted above.
From British Patent GB-A 2 112 513, a portable light with a fluorescent bulb and an incandescent bulb that are reversibly combined with one another in one housing is known. For the sake of commonly supplying voltage to the two bulbs, a set of batteries is provided which can be inserted into the bulb housing. The incandescent bulb is supplied directly from the battery via a reversing switch. The fluorescent bulb, conversely, is supplied from an electronic circuit which converts the direct voltage into a suitable alternating voltage. The known handheld work light has two substantial disadvantages: First, because of the batteries accommodated in the housing, it has a relatively high weight, which can cause fatigue when held in the hand for a long time. Second, because of the battery supply, the operating time is limited, while if the light is used frequently the batteries have to be replaced relatively often. Moreover, the batteries occupy a relatively large space, which increases the external dimensions of the light. Finally, for the narrow-beam illumination, it is desirable to use a stronger light source instead of the incandescent bulb.
Another battery-operated light with combined light sources is described in German Patent Disclosure DE-A 40 36 632. This light contains a rodlike light source in a first housing part, batteries in a second housing part, and an incandescent bulb with a reflector in a third housing part. By swiveling the first housing part, the light can be used either as a table light with a rodlike light source or as a flashlight with an incandescent bulb and reflector. Such a light cannot be used as a work light for mechanical work.
SUMMARY OF THE INVENTION
The object of the invention is to create a rodlike work light which enables not only wide-area illumination but also the illumination of a selective work field, which is easy to handle in terms of its size and weight, and is suitable for long-term operation.
Thus a work light according to the invention includes a rodlike bulb for the main circuit connection and a cylindrical, at least partly transparent housing surrounding the rodlike bulb, as well as a bulb with a light source that emits a narrow or aimed beam, on one face end of the housing. It also has an electrical connection cable and preferably a hangar hook.
The work light of the invention thus performs a dual function; that is, it illuminates a relatively large work field by way of the rodlike light source, and it illuminates a selective work field via the narrow-beam light source. In its usage options, the work light according to the invention is as widely applicable as conventional work lights. As usual, it furnishes an illumination of the area of the particular work field or installation area. Furthermore, it thus takes on the function of the flashlight that would otherwise be carried on one's person. If narrow-beam illumination of a particular location is needed, the bulb with the narrow-beam light source is then turned on in addition or as an alternative. Selected locations can thus be illuminated as needed, especially without glare from a flashlight used for lighting the area. By disposing the additional bulb on the face end of the generally slender light, the light can be aimed very well at the location to be lighted and can also be brought to the vicinity of more poorly accessible locations. The length of the light can advantageously be used to extend its range.
For this purpose, no additional device is needed in the light according to the invention. The narrow-beam light source can be provided in the form of a battery-powered bulb. In an advantageous embodiment of the invention, however, it is also connected to the connection cable, which expediently extends into the housing on the opposite end. Then the otherwise necessary demand for batteries for this application is dispensed with.
Expediently, the rodlike bulb is a fluorescent tube, and the narrow-beam light source is an incandescent bulb. Alternatively, the latter may also be a halogen bulb, for instance. To achieve a higher light yield or in other words better illumination of the work field, the narrow-beam light source is advantageously provided with a reflector.
To prevent shadows when the end-mounted bulb is used, the hangar hook can be mounted on the side, for instance on the end region where the bulb with the narrow-beam illumination is also located.
The electric circuit of the work light according to the invention can be embodied such that the rod like bulb and the additional narrow-beam bulb can each be switched on individually. It can also be provided that they both be turned on simultaneously, or that the narrow-beam bulb can be turned on in addition.
According to the invention, the work light is embodied with a fluorescent bulb and a low-voltage bulb, which are alternated reversibly from a common voltage source. The common voltage source is the alternating voltage network that can be connected via a main circuit connection. First means are provided for converting the alternating means voltage into a direct voltage, and second means are provided for converting the direct voltage into an alternating voltage with a frequency substantially elevated compared to the mains frequency; the voltages for operating the fluorescent tube and the halogen bulb can selectively be derived from the alternating voltage generated. The nucleus of the invention is to supply both bulbs with an alternating voltage, generated in the light, that is derived from the mains voltage and, with a higher frequency, assures that for both the halogen bulb and the fluorescent bulb, it is possible to dispense with heavy, voluminous transformers and chokes. As a result, and because of mains-connected operation, co
Dennison, Scheiner Schultz & Wakeman
Vo Tuyet T.
Wong Don
LandOfFree
Work light does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Work light, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Work light will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2492745