RELATED APPLICATION
FIELD OF INVENTION
[0002] The present invention relates to the field of lighting, with particular emphasis
on a track system for low voltage power supply, particularly for providing a low power
supply voltage for lighting of shelves for product display purposes.
BACKGROUND OF THE INVENTION
[0003] Track system for low voltage power supply is widely used in commercial lighting fields
such as supermarket shelves and freezer floors and for other commercial lighting purposes.
In order to ensure good electrical contact, a conventional track system for low voltage
power supply uses bare copper bars as positive and negative electrodes, and in order
to improve the effective utilization of electricity, often uses pure copper.
[0004] However, copper bars exposed to air are prone to produce patina (e.g. copper green),
which leads to a higher contact impedance between the electrical plug and the copper
bars used as electrodes, which affects the power supply. In order to overcome the
above problems, the surface of the copper bar is often plated, but this still cannot
solve the problem that a wet environment or an environment with high humidity will
cause the formation of liquid or moisture on the surface of the track and in the contact
areas used for electric power supply. The positive and negative poles of the exposed
copper bar are prone to be short-circuited by the liquid or moisture, causing frequent
failure of such track systems for low voltage power supply, which makes such track
systems suitable for low voltage power supply only for the dry environments.
[0005] From the prior art there are known conductive elastomers. A conductive elastomer
is a form of elastomer, often natural rubber or other rubber substitute, that is manufactured
to conduct electricity. This is commonly accomplished by distributing carbon or other
conductive particles, particularly conductive metal particles, throughout the raw
material prior to setting it. Conductive elastomers are often uniformly doped with
metal conductive particles in the rubber. Currently, conductive elastomers are mainly
used in the industry for shielding, anti-interference, contact buttons, signal conduction
and other small current applications. However, conductive elastomers are not used
power devices for power transmission. The main reason is that a simple conductive
elastomer, particularly a simple conductive rubber, has a relatively high impedance.
Conductive elastomers are often pressure-sensitive, with their conductivity varying
with the amount of pressure put on it. Although the impedance is relatively small
after being squeezed, when a conductive elastomer is directly used as a conductive
member for long distance power transmission, its impedance will increase with the
increase of the distance, resulting in very high Ohmic transmission losses, and the
so-called long distance here is equivalent to a very close distance in the traditional
sense by contrast, such as 10 cm.
BRIEF SUMMARY OF THE INVENTION
[0006] In view of the above problems, it is an object of the present invention to provide
an enhanced track system for low voltage power supply, particularly for power supply
of shelves used for product display, that enables a reliable operation even in humid
environments.
[0007] This problem is solved by a track system for low voltage power supply as claimed
in claim 1. Further advantageous embodiments are the subject-matter of the dependent
claims.
[0008] A track system for low voltage power supply enables a wide application range, high
power transmission efficiency and good safety performance, even in humid environments.
[0009] According to the present invention there is provided a track system for low voltage
power supply, comprising a power transmission track and an electrical plug that is
configured to be detachably connected to the power transmission track. A surface of
the power transmission track is provided with a first conductive bar, and the electrical
plug is provided with a second conductive bar, wherein the electrical plug is configured
such that the second conductive is contacted with the first conductive bar for low
voltage power supply. According to the present invention surfaces of the first conductive
bar and of the second conductive bar are wrapped or coated with a conductive elastomer,
wherein the conductive elastomer on the second conductive bar squeezes to contact
with the conductive elastomer on the first conductive bar when the electrical plug
is connected to the power transmission track, and wherein the portions of the conductive
elastomer that are squeezed due to their mutual contact when the electrical plug is
connected to the power transmission track take a reduced electric resistance value
to form a conductive contact portion for low voltage power supply.
[0010] According to a further embodiment, the second conductive bar is bent towards the
first conductive bar to form a bending portion extending in parallel with the first
conductive bar, and the bending portion squeezes and contacts with the first conductive
bar when the electrical plug is assembled with and connected to the power transmission
track; and wherein the shape of the conductive elastomer on the surface of the second
conductive bar is matched to the deformation of the second conductive bar.
[0011] According to a further embodiment, the second conductive bar extends out of the electrical
plug, and the protruding portion of the second conductive bar is surrounded by a common
rubber layer.
[0012] According to a further embodiment, the second conductive bar extends out of the electrical
plug, and the electrical plug is provided with a limiting portion extending in the
direction of the second conductive bar, and the lower end of the limiting portion
contacts the second conductive bar and applies a pressure thereto in the direction
of the power transmission track when the electrical plug is connected to the power
transmission track.
[0013] According to a further embodiment, the electrical plug comprises an upper end cover
and a lower end cover fixedly assembled with the upper end cover; wherein the lower
end cover is provided with an opening, and the bending portion is exposed from the
opening to the outside of the electrical plug.
[0014] According to a further embodiment, the electrical plug is assembled with and connected
to the power transmission track by a clamp fixedly mounted thereto; and the power
transmission track is provided with a clamping portion having two clamping plates,
and the lower ends of the two clamping plates of the clamp pass through the electrical
plug from top to bottom and are clamped on both sides of the clamping portion when
the electrical plug is connected to the power transmission track.
[0015] Compared with the prior art, the invention has the advantages that the copper bar
is coated with the conductive elastomer, which can not only make the conductive elastomer
play the role of protection and isolation, avoid the copper bar direct contact with
the air to generate copper rust, thereby preventing the copper bar from short circuit
caused by condensation of the liquid on the track in the humid environment, and at
the same time can fully utilize the characteristics that the conductive elastomer
has good electrical conductivity when subjected to pressure, when the electrical plug
is in contact with the track, it acts as a conductive medium to assist the copper
bar to transmit power, which makes the track system for low voltage power supply can
be safely used in humid environments, expands the scope of application, and effectively
ensures power transmission efficiency.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016]
- FIG. 1
- is a schematic structural view of a preferred embodiment of a track system for low
voltage power supply of the present application.
- FIG.2
- is an exploded view of the embodiment of FIG. 1.
- FIG.3
- is a perspective view of FIG.2 from below the track system.
- FIG.4
- is a schematic view of FIG. 2 from above the track system.
DETAILED DESCRIPTION OF THE INVENTION
[0017] The present application is illustrated by way of the following detailed description
based on of the accompanying drawings. It should be noted that illustration to the
embodiment in this application is not intended to limit the invention. The embodiments
of the present invention are described in detail below, and the examples of the embodiments
are illustrated in the drawings, wherein the same or similar reference numerals are
used to refer to the same or similar elements or elements having the same or similar
functions. The embodiments described below with reference to the accompanying drawings
are intended to be illustrative of the invention and are not to be construed as limiting.
[0018] For an introductory explanation, FIG.1-4 illustrate one embodiment of a track system
for low voltage power supply according to the present application. The track system
for low voltage power supply includes a power transmission track 1 and an electrical
plug 2 (electrical connector) that is configured to be detachably connected to the
power transmission track 1. The surface of the power transmission track 1 is provided
with at least one first conductive bar 11, and particularly may be provided with two
first conductive bars 11 extending in parallel with each other and spaced apart from
each other, as shown in Fig. 4. The electrical plug 2 is provided with at least one
second conductive bar 21 which can be contacted with the first conductive bar 11 to
get electricity. Particularly, the electrical plug 2 may be provided with two second
conductive bars 21 extending in parallel with each other and spaced apart from each
other, as shown in Fig. 2.
[0019] The track system for low voltage power supply further includes a connection portion
3 for connecting external low voltage power supply, as shown in FIG.1. Of course,
the track system for low voltage power supply further includes other components, such
as a corner adapting piece between the power transmission track and the power transmission
track, etc., however, as these are not the focus of this present application, they
are not elaborated here, and the connection portion 3 will be briefly explained below.
[0020] As shown in FIG.1, the connection portion 3 is preferably located at one end of the
power transmission track 1, and the connection portion 3 is connected to the low voltage
power supply via a copper bar 5. The low voltage power supply generally takes a value
of 24V or 48V. The copper bar 5 may be electrically connected to the power transmission
track 1 by welding, and the copper bar 5 transmits the power of the power supply end
to the power transmission track 1, and the electrical plug 2 takes power from the
power transmission track 1 to supply power to a lighting end. Of course, the copper
bar 5 may also be electrically connected to the power transmission track 3 in other
ways. This technology is well known to those skilled in the art and therefore will
not be described in detail herein.
[0021] According to the present application, the surfaces of the first conductive bar 11
and of the second conductive bar 21 are wrapped with conductive elastomer 4, particularly
with a conductive rubber. When the electrical plug 2 is connected to the power transmission
track 1, the conductive elastomer 4 on the second conductive bar 21 squeezes to contact
with the conductive elastomer 4 on the first conductive bar 11, and due to this squeezing
the resistance value of those portions of the conductive elastomer 4 that are pressed
against each other when the electrical plug 2 is connected to the power transmission
track 1, and that are contacted is reduced to thereby form a conductive contact portion
of a proper resistance value suitable for low voltage power supply. For details, please
refer to FIG.3-4.
[0022] When the conductive elastomer is not under pressure, it has a larger resistance value.
Because the conductive elastomer is wrapped on the surface of the conductive bars,
the conductive elastomer can exert an elastomeric (rubber) insulation function and
enable a good sealing performance to isolate the conductive bar from ambient air and
humidity or moisture. Even if the track system for low voltage power supply is used
in a humid environment, due to the isolation and insulation by the conductive elastomer,
it can also effectively prevent the conductive bar from coming into contact with any
liquid or moisture condensed on the track to thereby effectively preventing a short
circuit. Thus, according to the present invention power failures can be avoided and
the safety can be improved, to thereby overcome the problem of a conventional track
system for low voltage power supply that could only be applied in a dry environment.
Thus, according to the present invention the range of applications of track systems
for low voltage power supply can be significantly extended.
[0023] At the same time, the conductive elastomer is subjected to a certain pressure when
the electrical plug is connected to the power transmission track. Thus, the electric
resistance of the squeezed portions of the conductive elastomers will decrease, offering
a good conductivity for low voltage power supply. In this way, when the second conductive
bar is pressed into contact with the first conductive bar, the resistance value of
the squeezed contact portions of the conductive elastomer is reduced to form a conductive
contact portion for low voltage power supply, thus acting as a conductive power transmission
bridge between the first conductive bar and the second conductive bar, while other
portions not directly contacted and pressed are substantially unchanged in resistance.
Thus, the non-squeezed portions of the conductive elastomer continue to exert an excellent
insulating isolation function. Thus, the conductive bars can complement the conductive
elastomer and have good power transmission performance while being applicable to a
humid environment.
[0024] In order to enable the conductive elastomer on the second conductive bar 21 to be
effectively squeezed in contact with the conductive elastomer on the first conductive
bar 11, the second conductive bar 21 is resiliently biased against the first conductive
bar 11 toward a position, in which both conductive elastomer are sufficiently pressed
against each other to form a enabling the low voltage power supply. More specifically,
as shown in Fig. 2 the second conductive bar 21 bent toward the first conductive bar
11 to form a U-shaped bending portion 211 having a bar that extends in parallel with
the first conductive bar 11, wherein the bending portion 211 squeezes and is in contact
with the first conductive bar 11 when the electrical plug 2 is connected to the power
transmission track 1. The shape of the conductive elastomer 4 on the surface of the
second conductive bar 21 is adapted to the deformation of the second conductive bar
21, that is, the conductive elastomer 4 on the second conductive bar 21 is bent due
to the deformation of the second conductive bar 21, and the formed bending portion
211 squeezes and contacts with the conductive elastomer 4 on the first conductive
bar 11 to form a conductive contact portion for low voltage power supply.
[0025] The second conductive bar 21 extends out of the electrical plug 2, as shown in FIG.1.
In order to facilitate long-term use in a humid environment, the protruding portion
of the second conductive bar 2 extending out of the electrical plug 2 is surrounded
by a common rubber layer. Referring to Figs. 2 - 4, the electrical plug 2 comprises
an upper end cover 22 and a lower end cover 23 fixedly assembled with the upper end
cover 22. The electrical plug 2 is provided with a limiting portion 24 extending in
the direction of the second conductive bar 21. The lower end of the limiting portion
24 contacts the second conductive bar 21 and applies a pressure to the second conductive
bar 21 toward the direction of the power transmission track 1. Since the limiting
portion 24 can apply a force to the second conductive bar 21 in the direction of the
track 1, the second conductive bar 21 can be prevented from being pulled out of the
power transmission track 1 due to excessive force. And the pull-off preventing effect
provided by the limiting portion 24 is good. The limiting portion 24 may be disposed
perpendicular to the second conductive bar 21, that is, the limiting portion 24 may
be perpendicular to the inner wall of the upper end cover 22. Particularly, the limiting
portion 24 may be shaped as a limiting bar, as shown in FIG. 3, but it can also be
another structure that can achieve the anti-pull-off effect.
[0026] At the same time, it should be mentioned that in order to realize the squeezing contact
between the second conductive bar 21 and the first conductive bar 11, it is obvious
that the lower end cover 23 of the electrical plug 2 is provided with at least one
opening 231, so that the bending portion 211 of the second conductive bar 21, around
which the conductive elastomer 4 is wrapped, can extend through the opening 231 to
the outside of the electrical plug 2. FIG. 3 is a schematic view showing the structure
between the lower end cover 23 and the opening 231.
[0027] In order to facilitate maintenance, in the embodiment, the electrical plug 2 is detachably
connected to the power transmission track 1, so that only the faulty parts need to
be removed without the necessity of repairing the entire system, which saves cost.
[0028] More specifically, in the embodiment shown in the drawings, the electrical plug 2
is assembled and connected with the power transmission track 1 by means of a clamp
6 fixedly mounted on the electrical plug 2 that has at least one clamping plate 61,
and the power transmission track 1 is provided with a clamping portion 12, has a rectangular
profile in this example. When the electrical plug 2 is assembled and connected to
the power transmission track 1, the front end of the clamping plate 61 positively
grips behind the rear side of the clamping portion 12 of rectangular profile to thereby
fix the position of the electrical plug 2 relative to the power transmission track
1. At the same time, the clamping plate 61 is resiliently biases the electric plug
2 against the power transmission track 1, so that the associated bending portion 211
of the electric plug 2 is resiliently pressed against a slanted surface of the first
conductive bar 11 facing away from the clamping portion 12.
[0029] As shown in Fig. 2, the electrical plug 2 may comprise two clamping plates 61 resiliently
biased against each other like the two legs of a clothespin so that the two clamping
plates 61 may clamp the opposite front and rear side of the clamping portion 12 of
rectangular profile to thereby fix the position of the electrical plug 2 relative
to the power transmission track 1. As shown in Fig. 5, the lower ends of the two clamping
plates 61 of the clamp 6 can extend through the opening 231 to the outside of the
electrical plug 2 from top to bottom. At the same time, the associated bending portion
211 of the electric plug 2 is resiliently pressed against a slanted surface of the
first conductive bar 11 facing away from the clamping portion 12.
[0030] Of course, other connection methods can be used to detachably connect the electrical
plug to the power transmission track. There are various specific ways, which can be
designed according to actual situations, and this is not the protection focus of the
present application, and therefore is not enumerated here.
[0031] The above disclosure has been described by way of example and in terms of exemplary
embodiment, and it is to be understood that the disclosure is not limited thereto.
Rather, any modifications, equivalent alternatives or improvement etc. within the
spirit of the invention are encompassed within the scope of the invention as set forth
in the appended claims.
1. A track system for low voltage power supply, comprising
a power transmission track (1), and
an electrical plug (2) configured to be detachably connected to the power transmission
track (1), wherein
a surface of the power transmission track (1) is provided with a first conductive
bar (11),
the electrical plug (2) is provided with a second conductive bar (21), and
the second conductive bar (21) is contacted with the first conductive bar (11) when
the electrical plug (2) is connected to the power transmission track (1) for low voltage
power supply, characterized in that
surfaces of the first conductive bar (11) and the second conductive bar (21) are wrapped
with a conductive elastomer (4),
the conductive elastomer (4) on the second conductive bar (21) squeezes to contact
with the conductive elastomer (4) on the first conductive bar (11) when the electrical
plug (2) is connected to the power transmission track (1), and
those portions of the conductive elastomer (4) that are squeezed due to their mutual
contact when the electrical plug (2) is connected to the power transmission track
(1) take a reduced electric resistance value to form a conductive contact portion
for low voltage power supply.
2. The track system for low voltage power supply as claimed in claim 1, wherein
the second conductive bar (21) is bent towards the first conductive bar (11) to form
a bending portion (211) extending in parallel with the first conductive bar (11),
and the bending portion (211) squeezes and contacts with the first conductive bar
(11) when the electrical plug (2) is connected to the power transmission track (1);
and
the shape of the conductive elastomer (4) on the surface of the second conductive
bar (21) is matched to a deformation of the second conductive bar (21).
3. The track system for low voltage power supply as claimed in claim 1 or 2, wherein
the second conductive bar (21) extends out of the electrical plug (2), and the protruding
portion of the second conductive bar (2) is surrounded by a common rubber layer.
4. The track system for low voltage power supply as claimed in claim 2 or 3, wherein
the second conductive bar (21) extends out of the electrical plug (2), and the electrical
plug (2) is provided with a limiting portion (24) extending in the direction of the
second conductive bar (21), and a lower end of the limiting portion (24) contacts
the second conductive bar (21) and applies a pressure thereto in the direction of
the power transmission track (1) when the electrical plug (2) is connected to the
power transmission track (1).
5. The track system for low voltage power supply as claimed in any of claims 2 to 4,
wherein the electrical plug (2) comprises an upper end cover (22) and a lower end
cover (23) fixedly assembled with the upper end cover (22); the lower end cover (23)
is provided with an opening (231); and the bending portion (211) is exposed from the
opening (231) to an outside of the electrical plug (2).
6. The track system for low voltage power supply as claimed in any of the preceding claims,
wherein the electrical plug (2) is connected to the power transmission track (1) by
a clamp (6) fixedly mounted thereto; and the power transmission track (1) is provided
with a clamping portion (12) having two clamping plates (61), and the lower ends of
the two clamping plates (61) of the clamp (6) pass through the electrical plug (2)
from top to bottom and are clamped on both sides of the clamping portion (12) when
the electrical plug (2) is connected to the power transmission track (1).