1. Field of the Invention
The present invention relates to a push handle switch lampholder, and more particularly to the push handle switch lampholder that pushes a lower conductive plate to move like a see-saw by pushing a push handle to move back and forth and determines whether or not to pass a current to an upper conductive plate, so as to control the ON or Off of a light emitting element. In the meantime, a set of hooks is provided for connecting a power cable for an electric connection without the need of tying an UL knot.
2. Description of the Related Art
With reference to FIG. 1 for a conventional push handle switch lampholder 1, the push handle switch lampholder 1 comprises a cylindrical shell 11, an insulating plate 12, an insulating base 13 and a push handle switch 14, wherein the cylindrical shell 11 is electrically conductive and provided for screwing and connecting a light emitting element such as a light bulb (not shown in the figure), and a first electrode of the light emitting element is contacted with cylindrical shell 11 to electrically couple to a negative electrode of the power supply such as a utility power supply (not shown in the figure). The insulating plate 12 is installed at the bottom of the cylindrical shell 11, and a connecting groove 120 is formed thereon. The insulating base 13 is installed under the insulating plate 12 and includes a containing groove 130 concavely formed on the insulating base 13 for embedding a negative electrode plate 131 and a positive electrode plate 132, and an end of the negative electrode plate 131 is extended to the top of the insulating base 13 and abutted against the bottom of the insulating plate 12, and ends of the cylindrical shell 11, the insulating plate 12, the negative electrode plate 131 and the insulating base 13 are pivotally coupled, so that the negative electrode plate 131 and the cylindrical shell 11 are electrically connected. The positive electrode plate 132 includes a lower conductive plate 132a, at least two conductive plates 132b and an upper conductive plate 132c, and the lower conductive plate 132a is embedded into the insulating base 131. The conductive plates 132b are contained in both sides of the containing groove 130 respectively, and one of the conductive plates 132b proximate to the lower conductive plate 132a is electrically coupled to the lower conductive plate 132a, and the other of the conductive plates 132b is electrically coupled to the upper conductive plate 132c, and the upper conductive plate 132c is passed out of the connecting groove 120 and contacted with the second electrode of the light emitting element. A set of plug slots 133 is formed on an external surface of the insulating base 13 and their interior is corresponding to the negative electrode plate 131 and lower conductive plate 132a separately.
The switch 14 includes a push handle 141, a spring 142 and a metal plate 143, and the push handle 141 is contained in containing groove 130 for performing a pushing action reciprocally in the containing groove 130, and a middle section of the push handle 141 is hooked to an end of the spring 142. The metal plate 143 is substantially C-shaped, and an internal edge of the lower section is latched to the middle section of the push handle 141, and an internal edge of the upper section is hooked to the other end of the spring 142, so that when the push handle is pushed, the push handle is driven by an elastic force of the spring 142 to tilt towards one of the ends of the push handle 141, and the metal plate 143 is contacted with the conductive plates 132b on both sides respectively (as shown in FIG. 2). When the push handle 141 drives the spring 142 to link and move the metal plate 143 to tilt towards another end of the push handle 141, the metal plate 143 is released from the contact of the conductive plates on both sides.
In FIG. 3, both bare ends of the power cable 15 are plugged into two plug slots 133 respectively, so that the two bare ends of the power cable 15 push the negative electrode plate 131 and the lower conductive plate 132a to connect with each other for an electric connection. Therefore, the push handle 141 can push the metal plate 143 to contact the conductive plate 132b on both sides the same time to achieve an ON state, so as to electrically conduct the positive terminal of the power source to light up the light emitting element. On the other hand, the push handle 141 can push the metal plate 143 to disconnect the conductive plate 132b on both sides to achieve an OFF state, so as to turn off the light emitting element.
The connection between the push handle switch lampholder 1 and the power cable 15 relies on the negative electrode plate 131 and the lower conductive plate 132a to connect both bare ends of the power cable 15 only, so that when the power cable 15 is pulled accidentally or intentionally, the bare ends of the power cable 15 may be separated from the negative electrode plate 131 and/or the lower conductive plate 132a to result in a circuit disconnection. In the use of the conventional push handle switch lampholder 1, an UL knot 151 is tied at a position near the bare end of the power cable 15, and then both bare ends are plugged into two plug slots 133 respectively to achieve the effect of connecting the negative electrode plate 131 and the lower conductive plate 132a for an electric connection, and the UL knot 151 is intended for increasing the tensile resistance between the switch lampholder 1 and the power cable 15.
The conventional push handle switch lampholder 1 has the following drawbacks:
(1) Difficult Assembly: Since the lampholder 1 uses a number of conductive plates for conducting current to the light emitting element, therefore the overall assembling operation is complicated and tedious, and the position may be shift easily by an external force to affect the effect of the lampholder 1, so that the conventional lampholder 1 incurs a complicated assembling operation and the assembly may be loosened easily by external pushing or squeezing forces to affect the effect of use.
(2) Large Volume: Since the whole switch 14 must be accommodated into the containing groove 130, therefore the insulating base 13 is limited and its volume cannot be reduced effectively. As a result, the cost for the molding process of the insulating base 13 is high, and the large volume will also affect the storage and transportation costs.
(3) Unsmooth Pushing Operation: When a user pushes the push handle 141, a force greater than the elastic force of the spring must be applied to the push handle 141 before the metal plate 143 can be driven to contact with or separate from the positive electrode plates 132 on both sides. If the elastic force of the spring 142 is too large, then the user has to push the push handle 141 inconveniently. If the elastic force of the spring 142 is too small, then the push handle 141 will be too loose to cause a wrong movement. In addition, the spring 142 may become elastically fatigue after a long time of use, so as to affect the operation and effect of the lampholder 1.
(4) Short Service Life: Since the metal plate 143 and the conductive plates 132b on both sides are contacted to allow a current flow, and the contact position is a point or a line, the metal plate 143 produces a high temperature and becomes deteriorated or broken after a long time of use, so as to shorten the service life of the lampholder 1.
(5) Complicated Tie of UL Knot: The process of tying an UL knot 151 at a position proximate to a bare end of the power cable 15 is troublesome, not only increasing the manufacturing time and cost, but also increasing the storage and transportation costs since the UL knot 151 has a relatively large volume and it is difficult to reduce the total volume of the switch lampholder 1. Particularly, the UL knot increases the tensile resistance between the switch lampholder 1 and the power cable 15, but fails to assure a secured connection between the switch lampholder 1 and the power cable 15 when a strong force is applied.