Patent Application
20070279884
This section is intended to introduce the reader to various aspects of art, which may be related to various aspects of the present invention that are described or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present invention. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.
Computer systems often include a circuit board, a chassis, and electronic components. The circuit board is generally a motherboard, a system board, or a main board, and the electronic components often include a power supply, a sound card, a video card, a backplane, or the like. Typically, the electronic components connect to the circuit board, and the chassis supports the circuit board.
Unfortunately, if the circuit board is not adequately secured to the chassis, the circuit board and electronic components may move and/or disconnect from one another. Additionally, if the circuit board is not adequately secured to the chassis, it may be difficult to reliably connect the circuit board to the electronic components. An unsecured circuit board may shift out of alignment with the electronic components and potentially render a connection between the two unreliable.
One or more exemplary embodiments of the present invention will be described below. In an effort to provide a concise description of these embodiments, not all features of an actual implementation are described in the specification. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure.
The following discussion describes a fastener that, in certain embodiments, resiliently secures a circuit board to a chassis and grounds both sides of the circuit board. Advantageously, such a fastener may potentially reduce the number of connections to the circuit board by grounding both sides of the circuit board. Additionally, some of the following exemplary fasteners couple to the circuit board without the use of tools, thereby, in some embodiments, reducing the risk of a tool damaging the circuit board during installation. Finally, some of the subsequently discussed embodiments accommodate a variety of circuit boards with different thicknesses. Advantageously, some of these embodiments may lower computer system manufacturing costs by reducing the number of parts that are kept in stock to build a variety of computer systems, as a single type of fastener may couple to a variety of different types of circuit boards.
The illustrated fastener 10 includes a pair of feet or mounting bases 16 and 18, three bottom risers 20, 22 and 24, a bottom member 26, and a top member 28. As is described in greater detail below, the exemplary fastener 10 of
In the present embodiment, the bases 16 and 18 are each generally flat plates with a generally centrally disposed base fasteners 30 and 32, respectively. As described below, the exemplary bases 16 and 18 couple to the support structure 12 through the pair of base fasteners 30 and 32. The illustrated base fasteners 30 and 32 each include a base aperture 34 or 36 and a mount 38 or 40. The illustrated mounts 38 and 40 are cylindrical deformations in the support structure 12 that extend toward the fastener 10. In the current embodiment, the mounts 38 and 40 each thread through one of the base apertures 34 and 36, and the distal end of the mounts 38 and 40 deform over the top surface of the bases 16 and 18. Deforming the mounts 38 and 40 of the present embodiment expands their distal end beyond the width of the base aperture 34 or 36, thereby horizontally and vertically securing the mounts 38 and 40 within the base apertures 36 and 34. As will be appreciated, in alternate embodiments, other devices may secure the fastener 10 to the support structure 12, such as a welded joint, a fastener or a portion of a fastener that is integrally formed from the support structure 12, an adhesive connection, a latch, a buckle, a keyhole and bullet-nose pin, a catch, an array of hooks and loops, a rivet, a screw, a bolt, a slot and tab, friction members, or any other device adapted to directly or indirectly secure the fastener 10 to the base support structure 12. Moreover, the present technique encompasses, inter alia, embodiments that include different types of base fasteners 30 and 32, more than two base fasteners 30 and 32, and a single base fastener 30 or 32, for example. The illustrated base fasteners 30 and 32 are symmetrically disposed on each of the bases 16 and 18. However, in other embodiments both base fasteners 30 and 32 may be disposed on one base 16 or 18.
The illustrated bottom risers 20, 22, and 24 space the bottom member 26 away from the bases 16 and 18. The illustrated bottom risers 20, 22, and 24 extend generally perpendicularly from the bases 16 and 18 to the bottom member 26. In alternate embodiments, the some or all of bottom risers 20, 22 and 24 may extend at a non-perpendicular angle from the bases 16 and 18. Two of the bottom risers 20 and 24 are symmetrically disposed about the top member 28. Of course, in other embodiments the pair of bottom risers 20 and 24 may be integrated into a single bottom riser, integrated with the top member 28 or individually or collectively omitted. Similarly, some embodiments in accordance with the present technique do not include a bottom riser 22, such as embodiments employing a cantilevered bottom member 26 extending from a single base 16. Moreover, some embodiments in accordance with the present technique may not employ risers 20, 22 and 24, such as embodiments where the circuit board 14 is not substantially spaced away from the support structure 12. It should also be noted that some embodiments may employ some other device to space the circuit board 14 away from the support structure 12, such as a standoff or spacer under one or both bases 16 and 18, for example.
The illustrated bottom member 26 is a generally flat member of generally uniform thickness with a bottom member aperture 42 and a lower surface or bottom contact 44. The present bottom member aperture 42 has dimensions that are slightly larger than the top member 28. As is described in greater detail below, in the present embodiment the fastener 10 is manufactured from a single piece of sheet metal, and the top member 28 is constructed from material that was previously in place of the bottom member aperture 42. In other words, a portion of the material from the bottom member aperture 42 constitutes the top member 28. It should be noted that some embodiments in accordance with the present technique may not include a bottom member aperture 42, such as a fastener 10 with a non-integrally formed top member 28. The illustrated bottom contact 44 is a grounding clipping face, i.e., an area that conducts current from objects contacting the area to ground and mechanically secures objects contacting the area. To clarify, as used herein, the term “clipping” refers to securing rather than cutting. Alternatively, or additionally, the bottom contact 44 may be a clipping face, a contact face, or a grounding contact, for instance. The illustrated bottom contact 44 is a face of the material used to manufacture the fastener 10. As used herein, the term “face” refers to the two sides of a volume that have an aspect ratio (i.e., the ratio of length to width) closest to 1, and the term “edge” refers to the other surfaces or corners of the volume. For instance, a sheet of a material often has two opposing faces that have a relatively large surface area and edges that have a relatively small surface area. In alternate embodiments, the bottom contact 44 may be an edge 45 or a curved surface. Advantageously, a bottom contact 44 on a face may reduce pressure on the circuit board 14 at the area of contact, thereby potentially reducing wear on the circuit board 14.
The illustrated bottom risers 20, 22 and 24 simply support (i.e., support at opposing ends) the bottom member 26. However, some embodiments in accordance with the present technique include a cantilevered bottom member, a bottom member 26 supported at more than two ends, and a bottom member 26 supported by a stand off that contacts an area under the bottom member 26.
The illustrated top member 28 includes a top riser 46, a top extension 48, a U-shaped bend 50, and an upper surface or top contact 52. In the present embodiment, the top riser 46 is a resilient cantilevered beam that extends generally perpendicularly from the base 16. Of course, in other embodiments, the top riser 46 may extend from the base 16 at some other angle and/or may extend from some other portion of the fastener 10, such as the base 16, the bottom member 26, or the bottom riser 20, 22 and/or 24. While the illustrated top member 28 is integrally formed with the fastener 10, in other embodiments the top member 28 may be a separate component that couples to another portion of the fastener 10. The illustrated top riser 46 extends to a greater height or outward position than the bottom risers 20, 22 and 24, thereby positioning the top extension 48 above the bottom member 26. The illustrated top extension 48 is a resilient cantilevered beam that extends generally perpendicularly from the top riser 46 over the bottom member aperture 42. The present top extension 48 also extends generally parallel to the bottom contact surface 44. However, in other embodiments the top extension 40 may not be perpendicular to the top extension 48, parallel to the bottom contact surface 44, or both. The exemplary U-shaped bend 50 resides at a distal end of the top extension 48. The illustrated U-shaped bend 50 bends about one or more axes that are generally perpendicular to the top extension 48 (e.g., in the present embodiment, one leg of the U connects to the top extension 48 and the other leg of the U is a distal end). That is, the present U-shaped bend 50 dips down and then back up as it extends away from the top extension 48. Advantageously, the present U-shaped bend 50 may facilitate insertion of a circuit board 14 between the top member 28 and the bottom member 26. The curvature of the illustrated U-shaped bend 50 may reduce the pressure at the area of initial contact (i.e., peripheral leg of U) between the top member 28 and the circuit board 14 during insertion of the circuit board 14, and then gradually increase pressure as the circuit board 14 passes along the U-shaped bend 50 toward the center of the U. As will be appreciated, other embodiments in accordance with the present technique may not employ a U-shaped bend 50 and/or may employ a component with some other shape.
The illustrated top contact 52 is a grounding clipping face on the surface of the U-shaped bend 50 that faces generally in the direction of the bottom contact 44. Additionally, or alternatively, the top contact 52 may be a grounding contact, a clipping face, and/or a contact face, for example. The illustrated top contact 52 is on a face of the material used to manufacture the U-shaped bend 50. However, in other embodiments, the top contact 52 may be on an edge 45 of the material constituting the fastener 10. As described in greater detail below, the illustrated top contact 52 and bottom contact 44 may cooperate to ground both faces of the circuit board 14 and to secure the circuit board 14.
The support structure 12 may include a variety of components that support a circuit board, such as a chassis, a sub-pan, a device bay, shielding, a housing, a project box, or a server rack, for example. The illustrated support structure 12 is a sub-pan that is manufactured from a conductive material, such as sheet metal or a conductive plastic. Advantageously, the exemplary fastener 10 grounds the circuit board 14 through the support structure 12. Of course, in other embodiments the support structure 12 may be manufactured wholly or in part from non-conductive materials, such as plastic or ceramic materials.
With reference to
The illustrated circuit board 14 includes a top face 54, a bottom face 56 and an edge 58 with a thickness 60. Consistent with the previously discussed definition of the terms “edge” and “face”, the two faces 54 and 56 of the circuit board 14 are the two sides of the circuit board 14 with an aspect ratio closest to 1.
Advantageously, in various embodiments the fastener 10 secures boards 14 of a variety of ranges of thicknesses 60, such as boards 14 with a thickness greater than, less than, or equal to one millimeter, two millimeters, three millimeters, four millimeters, five millimeters, six millimeters, seven millimeters, or more, for example. In other words, in certain embodiments, the fastener 10 complies with boards 14 ranging in thickness 60 at least partially due to the resiliency of the top rise 46, the top extension 48, and the U-shaped bend 50 of the top member 28 and the bottom member 26. For example, the top member 28 can resiliently move away from the bottom 26 to increase the intermediate gap or space to support a generally board range of circuit board thicknesses 60.
The illustrated circuit board 14 includes a mating fastener 62 with a wedge-shaped portion 63. The illustrated mating fastener 62 is a board aperture through which the top member 28 inserts. However, in other embodiments the mating fastener may be an edge 58 of the circuit board 14 or a channel in the circuit board 14. Alternatively, or additionally, the mating fastener 62 may be another fastener 10, such as those listed above, for example. The exemplary wedge-shaped portion 63 is at the end of the mating fastener 62 expected to first contact the U-shaped bend 50 when securing the circuit board 14. As is subsequently discussed in greater detail, the illustrated wedge-shaped portion 63 cooperates with the U-shaped bend 50 to facilitate insertion of the circuit board 14 between the top member 28 and the bottom member 26. However, it should be noted that other embodiments in accordance with the present technique may not employ a wedge-shaped portion 63. Moreover, in some embodiments the circuit board 14 includes other features 50 to facilitate securing the circuit board 14, such as a divot in the top face 54 to receive the top contact 52, thereby locking the circuit board 14 in the fastener 10. Alternatively, or additionally, some embodiments may employ a ridge adjacent the mating fastener 62 to lock the circuit board 14 into the fastener 10. The mating fastener 62 may also include electrical contacts on one or both faces 54 and 56 adjacent the top contact 52 and the bottom contact 44. Beneficially, the illustrated fastener 10 grounds both faces 54 and 56 of the circuit board 14 through these electrical contacts.
An exemplary procedure to secure the circuit board 14 to the support structure 12 with the fastener 10 will now be described. Initially, in the present embodiment, the circuit board 14 is lowered onto the fastener 10, as indicated by arrows 64. As the circuit board 14 is lowered, the mating fastener 62 aligns with the top member 28. In the present embodiment, the top extension 48 of the top member 28 extends through the mating fastener 62. Additionally, the wedge-shaped portion 62 aligns with the U-shaped bend 50 near the distal end of the top extension 48. Once the circuit board 14 is properly aligned, the illustrated circuit board 14 slides between the top member 28 and the bottom member 26, as indicated by arrows 66. In the present embodiment, the U-shaped bend 50 rides up the wedge-shaped portion 63 and onto the top surface 54 of the circuit board 14. As the circuit board 14 slides between the top member 28 and the bottom member 26, the portion of the top extension 48 including the U-shaped bend 50 resiliently moves upward as indicated by arrow 68. In other words, the fastener 10 non-plastically flexes to facilitate an upward motion 68 of the top extension 48 and secure the circuit board 14. Advantageously, the resilient movement represented by arrow 68 facilitates securing a variety of boards 14 with different thicknesses 60. Of course, in other embodiments the fastener 10 may plastically deform during the process of securing the circuit board 14 to the fastener 10.
When the top contact 52 reaches the top face 54 of the present embodiment, the fastener 10 secures the circuit board 14 to the support structure 12. The fastener 10 biases the circuit board 14 between the top member 28 and the bottom member 26. Advantageously, in the illustrated embodiment, the circuit board 14 couples to the fastener 10 without the use of tools, thereby potentially reducing the risk of a tool damaging the circuit board 14. However, in other embodiments tools may be used to secure the circuit board 14 to the fastener 10. In the present embodiment, once the fastener 10 secures the circuit board 14, the fastener 10 grounds both faces 54 and 56 of the circuit board 14. However, in other embodiments, the fastener 10 may ground one face 54 or 56, no face 54 and 56, a component on or off the circuit board 14, and/or an edge 58 of the circuit board 14.
The illustrated fastener 10 is stamped from a single piece of 25/1000″ thickness,¾ hard stainless steel. However, as will be appreciated, other thicknesses and/or grades of metal may be employed. Moreover, substances other than metal may wholly or in part constitute the fastener 10, such as conductive and non-conductive plastics. Additionally, in other embodiments the fastener 10 may be manufactured from more than one piece of material, for example a fastener 10 with the top member 28 spot welded to riser 24.
With reference to
Once the fasteners 10 align with the mating fasteners 62, the present system board 72 then moves in the Y direction, as indicated by arrows 66. In the current embodiment, the fasteners 10 secure the system board 72, and, at substantially the same time, the male signal connectors 80 and 82 couple to the female signal connectors 84 and 86. That is, in the present embodiment, a single movement, represented by arrows 66, both engages the system board 72 with the fasteners 10 and engages the male signal connectors 80 and 82 with the female signal connectors 84 and 86. In other words, the male signal connectors 80 and 82 couple to the female signal connectors 84 and 86 at substantially the same time as the fasteners 10 couple to the mating fasteners 62. However, in other embodiments within the scope of the present technique these connections may occur at different times.
With reference to
