[0001] The present invention relates to a LED-based lamp for vehicle signaling lights, such
as tail lights, stop lights, turn indicator lights, and the like.
[0002] As known, the vehicle signaling lights tipically comprise a box-shaped housing made
of plastics and provided with one or more recesses each having an incandescent lamp
received therein. The recesses are closed by a mask of a translucent material which
may be differently coloured depending on the specific function of the light. The recesses
each are internally provided with a parabolic reflector for deviating the light beams
from the lamp into the desired direction, i.e., towards the mask.
[0003] As known, a drawback of the incendescent lamps is that they have a limited life,
which circumstance both leads to relatively frequent replacements and affects the
safety of the vehicle, mainly in consideration of the fact that a certain time can
pass before the driver notices the fault and replaces the lamp.
[0004] Another well known drawback of the incandescent lamps is that, in case of long stops
with the lights on, without the ventilation deriving from the movement of the vehicle,
they may cause a partial melting of the reflector. This drawback is particularly relevant
in old vehicles, in which the lights were designed for standing relatively short stops,
typically of about one hour, on the basis of obsolete standards.
[0005] The above drawbacks lead to provide the most recent vehicles with signaling lights
having LED-based lamps installed in lieu of conventional incandescent lamps. The LED-based
lamps generally comprise a printed circuit board bearing a plurality of LEDs (light
emitting diode) arranged, and in number, such as to meet the desired requirements
of brilliancy.
[0006] As known, the LED-based lamps overcome the above drawbacks of the incandescent lamps
because they have a high reliability, with a substantially unlimited life in relation
to the mean-life of a vehicle, as well as a very low operative temperature. In particular,
due to the high number of LEDs mounted on the board, even if a diode broke down (which
event is very rare per se) however the remaining LEDs would provide a sufficient light,
so that no replacement would be required.
[0007] A further advantage of the LED-based lamps is that they have an electrical input
that is considerably lower then the input of the conventional incandescent lamps.
This circumstance results in a lower consumption, i.e., a higher autonomy, of the
battery in case of long stops with the engine in motion and the lights out, which
stops may be necessary, for example, in case of long queues on the motorway.
[0008] However, the traditional lights designed for incandescent lamps usually are neither
equipped for housing LED-based lamps nor provided with the necessary electrical connections.
[0009] Therefore, recently attempts have been made of providing the LED-based lamps with
a connection compatible with the conventional lamp holders designed for lamps having
a bayonet coupling. However, the LED-bearing boards often are large-sized, which circumstance
affects the possibility of handling, and more particularly rotating, the lamp within
the respective recess, whereby the lamp cannot be installed.
[0010] It is a main object of the present invention to provide a LED-based lamp which overcomes
the above-mentioned drawbacks of the prior art lamps, with a higher degree of compatibility
and flexibility in relation to the conventional signaling lights designed for incandescent
lamps, and which can be installed easily and without requiring any adaptation to the
signaling light, even when the size of the lamp with respect to the recess affects
the possibility of handling the lamp for the installation.
[0011] In particular, it is an object of the invention to provide a LED-based lamp having
a high modularity in relation to the size and shape of the pre-existing, conventional
signaling lights.
[0012] The above objects and other advantages, which will better appear from the following
description, are achieved by a LED-based lamp having the features recited in claim
1, while the dependent claims state other advantageous, though secondary, features
of the invention.
[0013] The invention will be now described in more detail with reference to a few preferred,
non exclusive embodiments shown by way of non limiting examples in the attached drawings,
wherein:
Fig. 1 is a view in longitudinal, cross section of a portion of a conventional rear
light for vehicles, which is designed for incandescent lamps provided with bayonet
couplings;
Fig. 2 is a plan view of a LED-based lamp according to the invention, in a disassembled
configuration;
Fig. 3 is a view in cross section along line III-III of the LED-based lamp of Fig.
2, in a disassembled configuration;
Fig. 4 is a view similar to Fig. 3, showing the LED-based lamp in an assembled configuration;
Figs. 5, 6 are two views similar to Fig. 1 and showing two subsequent steps of the
installation of the LED-based lamp according to the invention in the signaling light;
Fig. 7 is a view in longitudinal cross section of a portion of a rear light for vehicles
of a conventional type differing from the light shown in Fig. 1 but always designed
for incandescent lamps;
Fig. 8 is a view in axial cross section of a LED-based lamp according to an alternative
embodiment of the invention, which is compatible fith a signaling light of the type
of Fig. 7, in a disassembled configuration;
Figs. 9, 10 are two views similar to Fig. 7 and showing two subsequent steps of the
installation of the LED-based lamp of Fig. 8 on the signeling light of Fig. 7;
Figs. 11-13 show three further alternative embodiments of the LED-based lamp according
to the invention.
[0014] With initial reference to Fig. 1, a rear signaling light for vehicles generally comprises
a box-shaped housing 10 provided with a plurality of side-by-side recesses 12, 14,
16, which are open to a front face of housing 10, which face is closed by a mask 18
made of a translucent material. The recesses each have a parabolic reflecting bottom
20, 22, 24 respectively, at the centre of which a lamp-holding socket or lamp holder
26, 28, 30 is formed, of the type with L-shaped grooves 26a, 28a, 30a suitable for
receiving an incandescent lamp 32, 34, 36 provided with a base 32a, 34a, 36a connectable
with a bayonet-like action. A first elastic foil 38, 40, 42 radially projects from
the bottom of the lamp holder to the inside thereof to contact the insertion end of
the base of lamp 32, 34, 36. A second foil (not shown) is incorporated in lamp holder
22 to contact the side wall of the base of the lamp. Both the foils of the lamp holders
are connected to the electric supply line of the vehicle, which is conventionally
designed, e.g., for generating a voltage of 12V or 24V at the contact ends, with a
current of about 1,8 A.
[0015] Having now reference to Figs. 2-4, a LED-based lamp 44 according to the invention
comprises a hollow metal mount 46 having a circular profile and provided with a cylindrical
base 47 for engaging one of the lamp holders 26, 28, 30 with a bayonet-like action
- with bosses 48 insertable in grooves 26a, 28a, 30a - and with a cylindrical support
end which is larger in diameter and on which a platform 50 is defined for mounting
a LED-based illuminator 52, as will be better described below.
mount 46 houses two pairs of contact clamps 54a, 54b and 56a, 56b arranged at right
angles to each other. The contact clamps are open towards platform 50 and are respectively
connected in pairs to a contact pole 58 formed on a boss at the insertion end of base
47, and to the lateral wall of base 47. mount 46 is filled with an insulating resin
(not shown for better clarity) in which the contact clamps are immersed.
[0016] LED-based illuminator 52 comprises a LED-bearing board 60 having a plurality of lighting
LEDs such as 62 mounted thereon, which are connected to a pair of contact projections
64a, 64b via a current dissipating circuit (not shown), which is incorporated within
LED-bearing board 60 and has the aim of lowering the value of the current to a level
which is compatible with the LEDs, e.g., a current of 30 to 80 mA. Contact projections
64a, 64b are insertable by friction into either the first or the second pair of contact
clamps, 54a, 54b, or 56a, 56b respectively. LED-bearing board 60 is hermetically closed
in a tranparent shell 66 made of plastics, with the sole contact projections 64a,
64b out of the shell. A plurality of lenses 68 are formed on the shell, each of which
is aligned to a respective LED for directing and intensifying the light emitted by
the LED.
[0017] In use, with reference to Figs. 5, 6, LED-based lamp 44 according to the invention
can be installed in one of the recesses of the signaling light in lieu of a conventional
incandescent lamp. For example, with reference to housing 12, at first metal mount
46 is installed into lamp-holder 26 with a bayonet-like, roto-traslatory action (Fig.
5). Thereafter, LED-based illuminator 52 is axially mounted onto mount 46, with contact
projections 64a, 64b inserted with friction fit into one of the pairs of clamps 54a,
54b or 56a, 56b (Fig. 6).
[0018] The two-part construction of the LED-based lamp according to the invention allows
the illuminator to be frontally installed into the housing without any rotation. As
it will be immediately understood, this allows the LED-based lamp according to the
invention to be installed into a pre-existing signaling light even when the the shape
of the recess does not allow the lamp to be rotated, which circumstance makes this
system very flexible and modular. Furthermore, the presence of two pairs of contact
clamps arranged at right angles to each other provides the LED-based lamp with a further
degree of modularity, because it allows a plurality of illuminators having different
shapes and sizes to be applied on a single type of mount 46.
[0019] Fig. 7 shows a portion of a rear vehicle signaling light of a conventional type differing
from the signaling light of Fig. 1 in that lamp-holder 126 is arranged with its axis
parallel to the front face of housing 110, on which face the coloured mask of a translucent
material 118 is applied.
[0020] An alternative embodiment of the lamp according to the invention is shown in Fig.
8, which is compatible with a signaling light of the type shown in Fig. 7. In the
embodiment of Fig. 8, base 147 of hollow metal mount 146 is bent at right angles whereby,
with the mount engaged into lamp-holder 126 of signaling light 110, platform 150 is
parallel to mask 118. Similarly to the previous embodiment, mount 146 houses two pairs
of contact clamps such as 154a, 154b arranged at right angles to each other, the clamps
being connected in pairs to the lateral wall of base 147 and to a contact pole 158
which is formed on a boss at the insertion end of base 147. Also with this embodiment,
mount 146 is filled with an insulating resin (not shown for better clarity) in which
the clamps are immersed. A LED-based illuminator is installable on metal mount 146,
which is identical to the illuminator described in the previous embodiment and consequently
will not be further described below.
[0021] In use (Figg. 9, 10), similarly to the previous embodiment, at first metal mount
146 is installed into lamp-holder 126 with a bayonet-like roto-traslatory action (Fig.
10). Thereafter, the LED-based illuminator is frontally mounted onto mount 146.
[0022] Figs. 11, 12, 13 are plan views showing three LED-based illuminators whose profiles
differ from the rectangular profile of the previous embodiments, i.e., a triangular
illuminator 252, a rhomboidal illuminator 352, and an arrow-shaped illuminator 452
respectively.
[0023] A few preferred embodiments of the invention have been described herein, but of course
many changes may be made by the person skilled in the art within the scope of the
inventive concept. In particular, other profiles for the illuminator can be easily
contrived by the person skilled in the art, e.g., circular or square profiles. Moreover,
the contact projection 64a, 64b on the LED-bearing board and the respective contact
clamps 54a, 54b and 56a, 56b on the metal mount could have profiles and sizes different
from what described above, in particular, cilindrical projections could be provided
which are insertable into corresponding contact seats with a complementary profile.
Of course, although in the examples shown the contact clamps are associated to the
mount and the contact projections are associated to the illuminator, this arrangement
could be easily reversed, i.e., the mount could be provided with a pair of contact
projections and the illuminator could be provided with one or more pairs of contact
clamps. Nevertheless, the lenses could be made apart from the shell, for example,
they could be formed on a transparent plate supported above the LED-bearing board
within the shell. Moreover, certain parts of the above-described LED-based lamp could
be not necessary in certain cases. For example, lenses 68 on shell 66 could be not
necessary in those cases in which a lower light intensity is required.
1. A LED-based lamp for installation in a vehicle signaling light having a lamp-holder
(26, 28, 30) for lamps with roto-traslatory coupling and provided with contact means
(38, 40, 42) connected to the electric supply line of the vehicle,
characterized in that it comprises:
- a mount (46, 146) shaped for engaging the lamp-holder (26, 28, 30) and provided
with at least a first pair of contact members (54a, 54b) connected to respective contact
surfaces (47, 58) arranged to engage said contact means (38, 40, 42) in the lamp-holder,
and
- a LED-based illuminator (52, 252, 352, 452) comprising a LED-bearing board (60)
supporting a plurality of lighting LEDs (62) connected to a second pair of contact
members (64a, 64b) engageable with friction fit with said first contact members (54a,
54b) for removably connecting the illuminator to the mount.
2. The LED-based lamp of claim 1, characterized in that said first contact members on the mount (46, 146) comprise clamps (54a, 54b) and
said contact elements on the LED-based illuminator (52) comprise projections (64a,
64b) insertable into said clamps with friction fit.
3. The LED-based lamp cof claim 1, characterized in that said first contact members on the mount comprise projections and said contact elements
on the LED-based illuminator comprise clamps into which said projections are insertable
with friction fit.
4. The LED-based lamp of claim 2 or 3, characterized in that it comprises two pairs of said clamps (54a, 54b) arranged at right angles to each
other.
5. The LED-based lamp of any of claims 1 to 4, characterized in that said mount (46, 146) has a base (47, 147) engageable into said lamp-holder (26, 28,
30), and a platform (50) connected to one end of the base, on which said first contact
members (54a, 54b) are arranged for receiving said illuminator.
6. The LED-based lamp of claim 5, characterized in that said base (147) is bent at right angles.
7. The LED-based lamp of any of claims 1 to 6, characterized in that said LED-bearing board (69) is housed within a shell (66) of an at least partially
transparent material.
8. The LED-based lamp of claim 7, characterized in that said shell (66) has a plurality of lenses (68) formed thereon which are substantially
aligned to the LEDs.
9. The LED-based lamp of any of claims 1-8, characterized in that said LED-based illuminator (52) has a substantially rectangular profile.
10. The LED-based lamp of any of claims 1-8, characterized in that said LED-based illuminator has a substantially triangular profile (252).
11. The LED-based lamp of any of claims 1-8, characterized in that said LED-based illuminator has a substantially rhomboidal profile (352).
12. The LED-based lamp of any of claims 1-8, characterized in that said LED-based illuminator has a substantially arrow-like profile (452).