This application claims priority of Chinese Application No. 200620000426.8, filed on Jan. 5, 2006.
The invention relates to an electric plug, more particularly to an electric plug for a Christmas lamp string that includes light-emitting-diode (LED) light bulbs.
With the advantages of low power consumption, low heat dissipation and long service life, use of light emitting diodes as the light source for a lamp string has been proposed. However, light-emitting diodes have polar property. Hence, they are not suitable for direct use with an alternating current power source. In addition, light-emitting diodes tend to be damaged under an unstable voltage.
Therefore, the object of the present invention is to provide an electric plug to overcome the above drawbacks associated with the prior art.
Accordingly, an electric plug of the present invention, comprises: a housing; a mounting seat mounted in the housing and having a front wall, two opposite side walls extending rearwardly from the front wall, a U-shaped transverse wall interconnecting the side walls and defining a resistor-receiving recess, and a partition wall disposed between the side walls, extending between the front wall and the U-shaped transverse wall, and cooperating with the side walls to define two opposite fuse-receiving grooves, each of the side walls being formed with a notch, the mounting seat further having a pair of wings that extend outwardly and respectively from and that cooperate with the side walls to define two opposite prong-receiving grooves; a pair of prongs, each of which extends outwardly of the housing through a respective one of the prong-receiving grooves, and each of which is provided with a protrusion that extends through the notch in a respective one of the side walls and into a respective one of the fuse-receiving grooves; a voltage-limiting component mounted in the resistor-receiving recess and having a pair of conductive clamping members extending into the fuse-receiving grooves, respectively; and a pair of fuses, each of which is clamped by a respective one of the clamping members and each of which extends into a respective one of the fuse-receiving grooves to contact the protrusion of a respective one of the prongs.
Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiment with reference to the accompanying drawings, of which:
Referring to
In this embodiment, the protrusion 23 of each of the prongs 2 is L-shaped. Each of the prongs 2 includes a plug end portion 21 for plugging into a socket of an alternating current power supply (not shown). The mounting seat 11 further has a rear transverse wall 110 that extends between the side walls 118 and that is formed with two opposite retaining holes 114. The electric plug further includes a pair of conductive wires 3, each of which is provided with an annular clamper 31 that is fitted into a respective one of the retaining holes 114. In this embodiment, the clampers 31 are made from copper, and are punched into a cup shape. The wires 3 are connected to a lamp string having a plurality of light-emitting diode light bulbs, as best shown in
In operation, when the plug end portions 21 of the prongs 2 are plugged into a socket of an alternating current power supply, the voltage-limiting component 4 operates to limit current and voltage of the lamp string. The fuses 5 provide protection for the light bulbs of the lamp string from burning out.
The housing 12 is formed with an access opening for access to the fuses 5 in the fuse-receiving grooves 116, and is provided with a movable cover 121 for covering the access opening.
The mounting seat 11 further has a rear wall 112 that is disposed on an exterior of the housing 12, and that is formed with a pair of slots 117 for extension of prongs of a plug of another lamp string therein. Each of the prongs 2 further has a rear end portion 22 extending from the plug end portion 21 for contacting the prongs of the plug of another lamp string inserted through the slots 117 into the housing 12.
Optionally, a rectifier (not shown) for converting an alternating current power signal into a direct current power signal can be incorporated in the electric plug of this invention.
With the inclusion of the voltage-limiting component 4 and the fuses 5 in the electric plug of this invention, the aforesaid drawbacks associated with the prior art can be eliminated.
While the present invention has been described in connection with what is considered the most practical and preferred embodiment, it is understood that this invention is not limited to the disclosed embodiment but is intended to cover various arrangements included within the spirit and scope of the broadest interpretation so as to encompass all such modifications and equivalent arrangements.
Number | Name | Date | Kind |
---|---|---|---|
4345223 | Chien-Chun | Aug 1982 | A |
5002501 | Tucker | Mar 1991 | A |
5034846 | Hodge et al. | Jul 1991 | A |
5451173 | Mai | Sep 1995 | A |
6753755 | Montague | Jun 2004 | B1 |