BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to component mounting apparatuses, and particularly to a subrack having code pins with simplified configurations for convenient use to mount plug-in units therein.
2. Description of the Related Art
Subracks for receiving plug-in units therein have been known in the electronics industry for a long time. A typical subrack comprises two sidewalls each having four corners, and four module rails fixed between the sidewalls, the module rails conventionally being screwed to the corresponding corners of the sidewalls. Bottom, top and back walls are attached to the subrack, and cooperate with the sidewalls to define a receiving space therebetween and an open side. The plug-in units can be inserted into and removed from the receiving space via the open side. The plug-in units typically comprise mounting panels engaging with two front module rails to thereby hold the plug-in units in place. For a thorough understanding of this kind of subrack, refer to the IEEE (International Electrical and Electronics Engineers) Standard 1101.10 established in 1996.
Various coding devices are used in subracks to enable plug-in units be correctly mounted to corresponding slide channels. Typically combinations of code pins are often used in subrack. U.S. Pat. No. 5,019,947 discloses a coding device for plug-in unit in subracks. The disclosed coding device comprises a subrack, a circuit board 6 and a plug connection connector 5. The subrack engages a plurality of coding elements 3 and a plurality of guide rails 2. The coding elements 3 defines two slots 4 therein. The plug connection connectors 5 respectively forms two webs 7, 8 corresponding to the slots 4 of the coding elements 3. The webs 7, 8 corresponding to the coding elements 3 so as to provide that coding occurs as soon as the individual coding elements engaged on the subrack complicate the manufacturing process of the subrack. In addition, for production of these rather elaborate components, complicated tools are required and manufacturing of the additional coding elements is quite expensive.
Thus, a new subrack for plug-in units with code pins which overcomes the above-mentioned problems is desired.
SUMMARY OF THE INVENTION
Accordingly, an object of the present invention is to provide a subrack for a plurality of plug-in units, the subrack having a plurality of code pins with simplified configurations.
Another object of the present invention is to provide a subrack easily assembled and having a plurality of code pins with simplified configurations for convenient use.
To achieve the above-mentioned objects, a subrack in accordance with a preferred embodiment of the present invention comprises a plurality of plug-in units, a pair of parallel sidewalls, a bottom wall and a top wall. Each plug-in unit engages a combination of code pins. Each of the bottom wall and top walls includes a first plate and a second plate engaged with the first plate. The first plate define a plurality of spaced slide channels for slidably receiving the plug-in units therein respectively, and forms a plurality of L-shaped flakes corresponding to respective combination of code pins in front of each slide channel. The height, length and deviation to slide channel of the flakes vary with different combinations of code pins on the mounting panel, in order to match the combinations of code pins and enable the plug-in units be inserted into the subrack for preventing from mis-inserting operation.
Other objects, advantages and novel features of the present invention will be drawn from the following detailed description of the preferred embodiment of the present invention with the attached drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an isometric assembled view of a subrack in accordance with the preferred embodiment of the present invention, together with a plug-in unit received therein;
FIG. 2 is an enlarged, isometric view of a part of a bottom wall of the subrack of FIG. 1;
FIG. 3 is similar to FIG. 2, but showing the bottom wall inverted;
FIG. 4 is an enlarged, isometric view of a first combination of code pins;
FIG. 5 is an enlarged, isometric view of a second combination of code pins;
FIG. 6 is an enlarged, isometric view of a third combination of code pins;
FIG. 7 is an enlarged, isometric view of a fourth combination of code pins;
FIG. 8 is a cross-sectional view of the bottom wall of FIG. 2, and showing the plug-in unit engaged therewith;
FIG. 9A is a schematic view of the a first flake engaging with the corresponding combination of code pins therewith;
FIG. 9B is a schematic view of the a second flake engaging with the corresponding combination of code pins therewith;
FIG. 9C is a schematic view of the a third flake engaging with the corresponding combination of code pins therewith; and
FIG. 9D is a schematic view of the a fourth flake engaging with the corresponding combination of code pins therewith.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1 to FIG. 3, a subrack 1 with code pins of the present invention is for receiving a plurality of spaced plug-in units 50 therein. For the sake of simplicity, only one plug-in unit 50 is shown and described hereafter. The subrack 1 of the preferred embodiment has two levels for plug-in units 50. It should be appreciated that the subrack 1 may alternatively be configured to have only one level, or three or more levels. For the sake of describing the preferred embodiment simply, only the upper of the two levels is described hereafter. The subrack 1 comprises two parallel sidewalls 10, and opposite top and bottom walls 24, 30 fixed between the sidewalls 10. The sidewalls 10 and top and bottom walls 24, 30 cooperatively define a space therebetween for receiving the plug-in units 50.
Referring also to FIG. 4, the plug-in unit 50 comprises a printed circuit board (PCB) 51, and a mounting panel 52 attached to a front end of the PCB 51. A pair of handles 56 is attached to top and bottom ends of the mounting panel 52 respectively. Each handle 56 is known in the art as an “injector/extractor handle,” and is used for inserting or extracting the plug-in unit 50 into or from the subrack 1. The handle 56 at a top end of the mounting panel 52 comprises a pair of upwardly-extending claws 57 at a top side thereof. The handle 56 at a bottom end of the mounting panel 52 comprises a pair of downwardly-extending claws 57 at a bottom side thereof. For the sake of simplicity, only the latter of the handles 56 is described hereafter. An alignment pin 54 extends inwardly from an inside of each end of the mounting panel 52. A screw 55 is movably retained in the mounting panel 52 adjacent each alignment pin 54. A screw head 550 located at an outside of the mounting panel 52. Prior to attachment of the plug-in unit 50 in the subrack 1, the screw 55 can be freely moved forward and rearward in the hole. The mounting panel 52 defines three square openings 61 at the bottom side therein, the side length of each opening 61 is denoted “a”. In each opening 61, a plug-in code pin 60 is retained. The length of each code pin 60 is the same with that of each opening, and also denoted “a”, the width of each code pin 60 is denoted “a/2”. The permutation of a code pin 60 in an opening 61 is four, that is upright-left, upright, transverse-up and transverse-down. Thus, the permutation of three code pins 60 is 64 (i.e., 4*4*4).
The top and bottom walls 24, 30 are made from corrosion-protected sheet steel, and are identical in the preferred embodiment. For the sake of simplicity, FIGS. 2 through 3 illustrate only the bottom wall 30. The bottom wall 30 comprises first and second plates 35, 31, which have a same thickness and are attached together by fastening devices such as rivets 33. Alternatively, other fastening means such as soldering can be used for connecting the first and second plates 35, 31 together. To prevent accumulation of static electricity, a plurality of conductive gaskets 32 is attached between the first and second plates 35, 31.
The first plate 35 comprises a main portion 350, and a recessed edge portion 355. A plurality of parallel, evenly spaced slide channels 351 is defined in the main portion 350, for slidingly receiving respective PCBs 51 therein. Preferably, the slide channels 351 are formed by a stamping process. A pair of spaced, divergent protrusions 352 is formed on the main portion 350 in front of each slide channel 351. The protrusions 352 cooperatively form a V-shaped entrance for guiding a corresponding PCB 51 into the slide channel 351. An alignment hole 353 is defined in the main portion 350 adjacent each pair of protrusions 352, corresponding to the alignment pin 54 of a respective plug-in unit 5O. A pair of side flanges 359 depends from opposite ends of the main portion 350 respectively. The side flanges 359 each define a screw hole (not labeled) and a hooking structure (not labeled), for connection of the first plate 35 to the sidewalls 10. Alternatively, other suitable joining means may instead be provided on the side flanges 359 for connection of the first plate 35 to the sidewalls 10.
The recessed edge portion 355 sequentially comprises first, second and third bent plates 355a, 355b, 355c integrally joined together at respective perpendicularly bent junctions therebetween. A row of spaced through apertures 356 is defined in the second bent plate 355b. A plurality of L-shaped flakes 40 are formed along the first plate 355a corresponding to the combination of three code pins 61 on the mounting panel 52. Preferably, the flakes 40 are formed by a stamping process. Every two flakes 40 are differential in height, width and deviation to the corresponding slide channel 351, varying with different mounting panel 52 with different combination of code pins 60.
Referring from FIG. 4, to FIG. 9D, in order to reduce manufacturing processes of the subrack 1 and coding a certain number of plug-in units 50, the first plate 355a of the subrack 1 forms the flakes 40 with simplified configuration. For the sake of simplicity, only the flakes 41, 42, 43, 44 are illustrated hereafter. The flake 41 comprises a vertical portion 41a and a horizontal portion 41b. The height of the flake 41 is denoted d1, the length is denoted e1 and the deviation to the slide channel 351 is denoted c1. The flake 42 comprises a vertical portion 42a and a horizontal portion 42b. The height of the flake 42 is denoted d2, the length is denoted e2 and the deviation to the slide channel 351 is denoted c2. The flake 43 comprises a vertical portion 43a and a horizontal portion 43b. The height of the flake 43 is denoted d3, the length is denoted e3 and the deviation to the slide channel 351 is denoted c3. The flake 44 comprises a vertical portion 44a and a horizontal portion 44b. The height of the flake 44 is denoted d4, the length is denoted e4 and the deviation to the slide channel 351 is denoted c4.
Referring from FIG. 4, to FIG. 7 and FIG. 9A to FIG. 9D, four flakes 40 and its corresponding code pins 60 are illustrated. In FIG. 4 and FIG. 9A, a code pin combination 60a, 60b, 60c is disclosed, each code pin 60a or 60b or 60c is engaged in transverse-up position. The corresponding flake 41 is configured as following: the height d1 is less than a/2, the length e1 is longer than 3a and the deviation c1 to the slide channel 351 is greater than 3a/2, in order to ensure that the combination of code pins 60a, 60b, 60c can avoid being blocked by the flake 41 and enable the plug-in unit 50 be inserted into the subrack 1.
In FIG. 5 and FIG. 9B, a code pin combination 60d, 60e, 60f is disclosed, each code pin 60d or 60e or 60f is engaged in transverse-down position. The corresponding flake 42 is configured as following: the height d2 is more than a/2, the length e2 is longer than 3a and the deviation c2 to the slide channel 351 is greater than 3a/2, in order to ensure that the combination of code pins 60d, 60e, 60f can avoid being blocked by the flake 42 and enable the plug-in unit 50 be inserted into the subrack 1.
In FIG. 6 and FIG. 9C, a code pin combination 60g, 60h, 60i is disclosed, each code pin 60g is engaged in upright-left position and code pins 60h or 60i is engaged in transverse-down position. The corresponding flake 43 is configured as following: the height d3 is more than a/2, the length e3 is greater than 2a and less than 5a/2, the deviation c3 to the slide channel 351 is greater than a/2 and less than a, in order to ensure that the combination of code pins 60g, 60h, 60i can avoid being blocked by the flake 43 and enable the plug-in unit 50 be inserted into the subrack 1.
In FIG. 7 and FIG. 9D, a code pin combination 60j, 60k, 60l is disclosed, each code pin 60j is engaged in upright-left position and code pins 60k or 60l is engaged in transverse-down position. The corresponding flake 44 is configured as following: the height d4 is more than a/2, the length e4 is greater than 2a and less than 5a/2, the deviation c4 to the slide channel 351 is greater than a/2 and less than a, in order to ensure that the combination of code pins 60j, 60k, 60l can avoid being blocked by the flake 44 and enable the plug-in unit 50 be inserted into the subrack 1.
Referring to FIG. 2 and FIG. 3 again, the second plate 31 comprise a vertical portion 315, and first and second horizontal portions 316, 310 extending from bottom and top sides of the vertical portions 316, 310 extending from bottom and top sides of the vertical portion 315 in respective opposite directions. A row of screw apertures 314 is defined in the vertical portion 315, corresponding to the row of through apertures 356 of the first plate 35. A plurality of pairs of rectangular openings 318 is defined in a front part of the first horizontal portion 316. The pair of rectangular openings 318 can engagingly receive the claw 57 of the handle 56 respectively. A plurality of extensions 311 is formed at a rear side of the second horizontal portion 310, for aligning with the alignment holes 353 and creating corresponding spaces for receiving the gaskets 32. Rivets 33 are extended through the river holes (not labeled), thereby securely joining the first and second plates 35, 31 together.
Each gasket 32 is adhered to the extension 311. Other suitable attachment means such as screw jointing can alternatively be adopted.
In assembly of the plug-in unit 50 into the subrack 1. For the sake of simplicity, only the bottom wall 30 and the corresponding handle 56 of the plug-in unit 50 are shown and described hereafter. The plug-in unit 50 is positioned adjacent a corresponding pair of protrusions 352. The plug-in unit 50 is pushed inwardly to slide through the entrance of the protrusions 352 and into the corresponding slide channel 351. When the PCB 51 almost reaches a connector (not shown) located at a rear of the subrack 1, the alignment pin 54 extends into the alignment hole 353 to guide the PCB 51 to accurately engage with the connector. If the combination of code pins on the mounting panel 52 unmatched with the flake 40 on the first plate 355a, the plug-in unit 50 is blocked outside the subrack 1 and cannot be inserted into the subrack 1 thereafter, which functions as a mis-inserting protection. Once the combination of code pins on the mounting panel 52 matches the corresponding flake 40, the plug-in unit 50 can be completely slid into the subrack 1 and engaged with the connector. Then the handles 56 engage in the corresponding pair of rectangular openings 318 to prevent the plug-in unit 50 from being accidentally withdrawn from the subrack 1. In this state, the gasket 32 resiliently abuts against the alignment pin 54 to form a grounding path between the bottom wall 30 and the plug-in unit 50. Finally, the screw 55 is extended through the corresponding through aperture 356 of the first plate 35 and engaged in the corresponding screw aperture 314 of the second plate 31. The plug-in unit 50 is thus secured in the subrack 1.
To remove the plug-in unit 50 from the subrack 1, the screw 55 is disengaged from the screw aperture 314. The handle 56 is rotated downwardly so that it disengages from the rectangular openings 318. The plug-in unit 50 can then be easily slid out from the subrack 1.
It is understood that the invention may be embodied in other forms without departing from the spirit thereof. Thus, the present example and embodiment are to be considered in all respects as illustrative and not restrictive, and the invention is not to be limited to the details given herein.
Patent Application
20050128718
