Patent Application
20100158633
1. Technical Field
The present disclosure generally relates to fixing systems for circuit boards.
2. Description of Related Art
Electronic devices often include circuit boards. A circuit board is usually fixed to a housing of the electronic device via a fixing system. In a frequently used fixing system, the circuit board is connected to a shielding plate. The shielding plate is riveted with a plurality of studs, and a plurality of screws extend through the circuit board and are engaged in the studs.
However, the studs must be riveted onto the shielding plate. This process requires special equipment and considerable man-hours, thus increasing both manufacturing time and costs.
Therefore, a fixing system that can overcome the described limitations is desired.
The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present invention. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.
Referring to
The plate portion 11 is a thin sheet made of iron, plastic or other material. In the illustrated embodiment, the plate portion 11 is applied in a liquid crystal display device for shielding electromagnetism, and is thus a metallic plate, such as an iron plate. The plate portion 11 defines a plurality of ventilation holes 111 and at least one fixing hole 112. In the illustrated embodiment, there are four fixing holes 112 corresponding to the number of fastening units 12. In order to shield electromagnetism, a diameter of each ventilation hole 111 is less than 5 mm. Each fixing hole 112 is polygonal. Preferably, each fixing hole 112 is a regular polygon; for example, a regular triangle, square, or hexagon. In the illustrated embodiment, the fixing holes 112 are square, but alternatively the fixing holes 112 may have other shapes.
Referring also to
The latching hooks 125 are formed on sidewalls of the base 123 and protrude out from the sidewalls. The latching hooks 125 are elastic, and thus deformable. In the illustrated embodiment, each latching hook 125 is wedge-shaped, and includes an inclined surface 128. The inclined surface 128 faces a direction generally away from the resisting plate 124. The latching hook 125 includes a first resisting surface 126 at a free end thereof, the first resisting surface 126 facing the resisting plate 124. A bottommost portion of the latching hook 125 has a uniform width as measured along a radial direction from a center axis (not shown) of the fastening unit 12. A width of the latching hook 125 at the inclined surface 128 as measured along the radial direction from the center axis of the fastening unit 12 progressively decreases in a direction away from the first resisting surface 126. The resisting plate 124 includes a second resisting surface 129 facing the first resisting surface 126. A slot (not labeled) is defined between the first and second resisting surfaces 126, 129, for receiving a side edge of the plate portion 11 which bounds the corresponding fixing hole 112. A distance between the first and second resisting surfaces 126, 129, i.e., a vertical width of the slot, is substantially the same as or slightly larger than a thickness of the plate portion 11.
The engaging portion 122 of each fastening unit 12 defines an engaging hole 127. The engaging hole 127 may be a threaded hole or a hole bounded by a smooth cylindrical wall. In the illustrated embodiment, each fastener 13 is a screw for engaging in the engaging hole 127. When the engaging hole 127 is bounded by a smooth cylindrical wall, the fastener 13 is a self-tapping screw.
The circuit board 14 defines at least one mounting hole 141. In the illustrated embodiment, there are four mounting holes 141 corresponding to the fixing holes 112.
In assembly of the fixing system 10, the engaging portion 122 and the base 123 of each fastening unit 12 are extended through a corresponding one of the fixing holes 112 of the plate portion 11. As the base 123 passes through the fixing hole 112, the latching hooks 125 are squeezed by the side edges of the plate portion 11 which bound the fixing hole 112. The latching hooks 125 deform, thus allowing the base 123 to pass through the fixing hole 112. The resisting plate 124, being larger than the fixing hole 112, cannot pass through the fixing hole 112. After passing through the fixing hole 112, the latching hooks 125 rebound to a relaxed state. The plate portion 11 is held between the first resisting surfaces 126 of the latching hooks 125 and the second resisting surface 129 of the resisting plate 124. The engagement of the base 123 in the fixing hole 112 with a matching shape prevents the fastening unit 12 from rotating relative to the plate portion 11. The fastening unit 12 is thus fixed to the plate portion 11.
To mount the circuit board 14 to the plate portion 11, the circuit board 14 is placed on the fastening units 12, with the engaging portions 122 aligned with the mounting holes 141. In one embodiment, annular upper steps (not labeled) of the engaging portions 122 support a bottom of the circuit board 14, and annular reduced topmost parts of the engaging portions 122 which are above the steps are received in the mounting holes 141. The fasteners 13 are passed through the mounting holes 141 and engaged in the engaging holes 127, and circuit board 14 is thus fixed to the plate portion 11.
In the fixing system 10, the fastening units 12 are fixed to the plate portion 11 by way of part of each fastening unit 12 engaging in the corresponding fixing hole 112. The fixing system 10 can thus be implemented in a single movement of the plate portion 11 onto the fastening units 12. As the base 123 of each fastening unit 12 passes through the fixing hole 112, the inclined surfaces 128 are elastically deformed inwardly and allow the base 123 to move through. Thus implementation of the fixing system 10 is convenient, with assembly of the circuit board 14 to the plate portion 11 quick and inexpensive.
Referring to
Finally, while various embodiments have been described and illustrated, the disclosure is not to be construed as being limited thereto. Various modifications can be made to the embodiments by those skilled in the art without departing from the true spirit and scope of the disclosure as defined by the appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 200810306408.6 | Dec 2008 | CN | national |
