Patent Application
20150295396
1. Field of the Invention
The present invention relates to a surface mounted protection unit, and more particularly to an explosion-proof and surface mounted circuit protection unit.
2. Description of Related Art
A circuit protection unit is applied on a circuit board to protect the circuit board. When a passing current is excessive, a fuse of the circuit protection unit is heat-melted and fractured to form an open circuit to interrupt the current. A conventional circuit protection unit has a base, two conductive units, a fuse, and a cover. The conductive units are mounted on the base at an interval. The fuse is electrically connected between the conductive units. The cover is mounted on and seals the base to accommodate the fuse. In use, the circuit protection unit is electrically soldered on a circuit board by the conductive units by means of surface mount technology.
However, when the passing current is overloaded and the fuse is heated and melted, a temperature in the circuit protection unit is increased, and then a volume of air in the circuit protection unit is increased. A barometric pressure of the air is increased, and then a gas explosion may occur easily. When the gas explosion occurs, the cover may be detached from the base.
The main objective of the present invention is to provide an explosion-proof and surface mounted circuit protection unit to resolve the above-mentioned problems.
The explosion-proof and surface mounted circuit protection unit has a base module, a fuse, and a base cover.
The base module has a base body and two conductive units. The base body is insulated, and has two combining segments and multiple first combination parts respectively formed on the combining segments. The conductive units are respectively mounted on the combining segments at an interval. Each conductive unit extends from a top side to a bottom side of the combining segment.
The fuse is mounted on the base module and electrically connected with the conductive units.
The base cover is mounted on the base module and has a cover body, multiple second combination parts, and an interval. The cover body covers the base module and encloses the fuse. The second combination parts protrude on the cover body and are respectively combined with the first combination parts tightly. The interval is formed between the cover body and the base body.
Other objectives, advantages and novel features of the present invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.
With reference to
With reference to
The base body 11 is made of an insulation material, such as ceramics, plastic and so on. The base body 11 has two combining segments 111, an interval segment 112, two first combination parts 13, and a base recess 14. The combining segments 111 are respectively defined as two ends of the base body 11. The interval segment 112 is connected between the combining segments 111. The first combination parts 13 are respectively recessed in the combining segments 111. The base recess 14 is recessed in a top side of the interval segment 112 of the base body 11.
The conductive units 12 are made of conductive material, are mounted on the base body 11 at an interval, and are mounted on the combining segments 111 respectively. Each conductive unit 12 is formed into a U shape and extends from a top side to a bottom side of the combining segment 111. Each conductive unit 12 has an abutting part 121, a soldering part 122, and a pad hole 123. The abutting part 121 is defined as a top side of the conductive unit 12, and is located on the top side of the combining segment 111. The soldering part 122 is defined as a bottom side of the conductive unit 12, and is located on the bottom side of the combining segment 111. The pad hole 123 is formed through the abutting part 121 and is aligned with the first combination part 13.
With reference to
With reference to
Alternatively, the first combination parts 13 may protrude from the top side of the base body 11, and the second combination parts 32 may be recessed in the bottom side of the cover body 31.
With reference to
With reference to
When the fuse 20 is heat-melted and fractured, a volume of air in the explosion-proof and surface mounted circuit protection unit is expanded due to high temperature. Therefore, a barometric pressure in the explosion-proof and surface mounted circuit protection unit is increased. The expanded air is discharged via the interval W between the base module 10 and the base cover 30 to prevent a gas explosion. When the expanded air is discharged via the interval W, the base cover 30 is combined with the base module 10 firmly since the first combination parts 13 and the second combination parts 32 are combined with each other tightly. Therefore, the base cover 30 can be kept from detaching from the base body 10. Furthermore, with reference to
From the above description, it is noted that the present invention has the following advantages. The expanded air can be discharged via the interval W to prevent gas explosion. The tightly combined first combination parts 13 and the second combination parts 32 can keep the base cove 30 from detaching from the base body 10. Therefore, the explosion-proof and surface mounted circuit protection unit can provide a protecting effect for the circuit board. The base recess 14 can keep the fractured fuse 20 from electrical contact again to further protect the circuit board.
Even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.
