Patent Application
20090203260
The invention relates to a device for holding a lamp in accordance with the generic part of claim 1.
Such a device is known, e.g. from the 2007 product catalog of the applicant as a holder for GR14q compact fluorescent lamps of the PL-R Eco type of the Philips company.
Another device with which a compact fluorescent lamp 2 GB-1 can be installed by executing a plug-and-rotate motion is known from EP 1 348 902 A1.
The considerable advantage of compact fluorescent lamps for illumination is due to their high illuminating power with low current consumption and their long service life. There are compact fluorescent lamps on the market in various wattage levels, classified according to their number of watts, so that there is a lamp with a suitable wattage for every application.
It is advantageous for the manufacturers of lighting units if the lamp holder or socket of a standard device only can accept lamps with a predetermined or a maximally admissible wattage and/or of a predetermined lamp type in the light fixture. This can ensure that the body of the light fixture, the reflector or, in the case of installed light fixtures, the parts surrounding the light fixtures are protected from too much heat from the lamp. Such a device did not exist up to the present in standard devices for holding compact fluorescent lamps.
It is therefore an object of the present invention to provide a device for holding compact fluorescent lamps in which a lamp base can be fixed in a socket by a plug-and-rotate motion in such a manner as to can ensure that only suitable lamps can be inserted into the light fixture.
This object is attained by a device for holding a lamp with the features of claim 1, in particular with its characterizing features, according to which the cylindrical projection of the lamp base has a central plug projecting toward the socket, which plug forms a lamp key coded for a predetermined lamp wattage, and that the floor of the socket has a hole corresponding to the plug, which hole forms a socket key coded for the maximally admissible lamp wattage for the socket, and that the lamp base can only be inserted into the socket when the lamp wattage indicated by the lamp key does not exceed the maximally admissible lamp wattage defined by the socket key.
The outer socket part key and the inner socket part key make it possible to prevent the insertion of lamps into light fixtures whose wattage is too great for the particular model of light fixture. Thus, this can effectively prevent damage from high temperatures as a consequence of the radiation of heat of the lamp inside the light fixture for the body of the light fixture or for the reflector as well as outside of the light fixture on mounting parts or parts of the surroundings. However, at the same time the key combinations make it possible to insert lamps with a lesser wattage than the maximal wattage permitted for the socket into a light fixture so that the user of the light fixture in question is otherwise free in his selection of the lamp wattage and illuminating wattage.
However, it is conceivable in one embodiment that the lamp base can only be fitted into the socket if the lamp key and the socket key are coded for the identical lamp wattage.
However, the embodiment is preferred in which the socket key characterizing a predetermined lamp wattage allows the insertion of all lamp bases whose lamp keys coded for an identical or lesser lamp wattage.
Concretely speaking, the keys are designed in such a manner that the socket key is constituted as a lug directed radially inward to the hole center and that the lamp key is designed as an outwardly open cutout of the plug.
Lamp bases for lower lamp wattages have wider outwardly open cutouts on the plug side than lamp bases for higher lamp wattages.
In conformity therewith the lug on the socket in sockets for higher admissible lamp wattages is offset relative to those with lower admissible lamp wattages by a predetermined angle counter to the rotary movement to be performed for installation.
A concrete embodiment provides that the offset of the angle is 45° per lamp wattage range and the outwardly open cutout is increased by 45° per lamp wattage range toward the rotary movement to be performed for fixing.
The previously cited concrete angles result in seven possible keys, taking into account tolerances for structural components, with which an insertion of a lamp with non-admissible lamp wattage is reliably avoided, taking into account the rotary motion of 30° necessary for fixing. In this manner the number of keys is maximized while ensuring safety.
Just as a lamp wattage that is too high, even the wrong lamp type can result in damage to the light fixture. This can be imagined, e.g. if the light fixture for a lamp is intended for a long cylindrical lamp body and instead a lamp with a substantially spherical lamp body is inserted. The spherical lamp body has a greater diameter than the cylindrical lamp body and as a consequence less distance to the body of the light fixture. Even this can result in an inadmissible heating of the body of the light fixture, of the reflector or of the surroundings, resulting in thermal damage.
The initially posed problem of a device is solved in this sense with the features of the claim 10, in particular with the characterizing features, according to which the cylindrical projection on the lamp base comprises at least one key recess on its outer circumference, which recess characterizes a predetermined lamp type and the collar on the socket has at least one key projection on its inner circumference and also coded for a predetermined lamp type, which socket can only be fitted into the socket if the key recess and the key projection are coded for compatible lamp types.
A preferred embodiment provides that up to five key recesses and up to five corresponding key projections are provided.
For special applications an embodiment is provided that is characterized in that the socket can only be fitted into the socket if the key recess and the key projection are coded for identical lamp types.
Finally, the retaining formations on the lamp base are designed as retaining projections and the retaining formations on the socket are designed as L-shaped grooves so that the inner and outer retaining formations form a type of bayonet lock.
The drawings will clarify further advantages of the invention. Therein:
A socket is identified with reference numeral 10 and a lamp base with reference numeral 11 in all figures.
As is apparent in particular from
The outwardly open cutout corresponds to the lamp key 31 of key pair 7 in
In
The L-shaped collar grooves 18 of the socket 10 that form the retaining formations 19 are nonuniformly angularly spaced from each other. Retaining projections 20 on the lamp base fit with the collar grooves 19. The retaining projections 20 are angularly spaced from each other on the circumference and the distances between each corresponding collar grooves 18 or retaining projections 20 and the respective next collar groove 18 and/or retaining projection 20 are the same. This ensures that the lamp base 11 can only be inserted into socket 10 in a one angular position relative to the socket since only then can each retaining projection 20 fit into its corresponding collar groove 18.
It can be readily be seen with reference to
The lamp base 11 is now inserted into the socket 10 with the retaining projections 20 fitting into the legs of the L-shaped collar grooves 18 that extend perpendicular to the socket floor 14. At the same time the unillustrated lamp contact pins engage into the inner part apertures 16 and the protections 36 of the inner part catch 33 come to rest in front of the shallow flank 23 of the sawtooth 22 in the corresponding recess.
Subsequently, the lamp base is moved about 30° in the retaining rotational sense V so that retaining projections 20 move into the legs of the collar grooves 18 extending parallel to the socket floor 14, thereby effecting a bayonet-like locking of the lamp base 11 in the socket 10. At the same time engagement projections 36 pass over apices 38 formed by the flanks 23 and 24 of the sawteeth 22 and engage behind the apices 38. Thus, accidental loosening of the bayonet locking of socket part 11 and socket part 10 is prevented. In order to unlock, socket part 11 is moved opposite socket part 10 in a rotational loosening sense E (unlocking direction) by about 30° and then pulled out of the outer socket part.
An alternative key for coding to usable lamp types will be described with reference to
Key projections 39 formed on the socket on the inner surface of the collar 12 and projecting toward the hole center Z serve as key elements. An inner surface 40 of the inner part cylindrical projection 27 is formed with key recesses 41, also termed key windows, corresponding to the projections 39. The lamp base 11 can only be inserted into the socket 10 when the number and orientation of the key recesses 41 of the lamp base 11 correspond at least to the key projections 39 of the socket 10. The lamp types admissible for a socket can be characterized by the key protections 39. The key recesses 41 formed on the lamp base 11 also characterize a lamp type. With this key system light fixtures can be provided with sockets 10 that only allow use of a predetermined lamp type or of a group of lamp types compatible with each other.
Comparison of
In a concrete embodiment of the invention the lamp key 31 and the socket key 26 are designed in such a manner that there is a total of seven key pairs as shown in
It must be imagined for the interfitting of the socket 10 and the lamp base 11 that the lamp base 11 of each key pair is fitted into the socket 10 by counterclockwise pivoting relative to the view plane.
The pairings of socket 10 and lamp base 11 shown in
Therefore, even the rudimentary lamp key 31 of the key pair 1 can be eliminated so that the lamp base of the key pair 1 can also make do entirely without the lamp key 31.
The socket 10 has the lug 25 as socket key. This lug is present in each key pair. The plug 25 is offset, starting from the lowest lamp wattage range, by 45° opposite to the rotational sense V, that is, in the rotational sense E, for every next-higher lamp wattage range.
In sum, the invention has two key systems between the socket 10 and the lamp base 11 available that are different but can be combined with one another and by means of which the use of the wattage or of a wattage range as well as of the type of unsuitable lamps and the consequent damage can be effectively avoided in light fixtures.
