Claims:
I claim
1. A circuit board edge guide mount designed to be individually supported on inside facing opposite walls of spaced parallel sideplates to provide insertion guidance for and mounting of the opposite edges of circuit boards mounted between and generally transversing the space between the sideplates, including: a guide mount of flexible material having a longitudinally extended back portion from a board edge entrance end to a bottom end; first index means adjacent the entrance end; second index means adjacent the bottom end; opposite sides extending out from said back portion generally in spaced parallel relation through most of the length of said guide mount and presenting card edge opposite side engaging parallel edges; with board edge entrance ends of said opposite sides formed outwardly to present a ramped board edge entrance guide throat at the board edge entrance end of the guide mount; wherein, said first index means is a bent over position indexing and mount tab at the board edge entrance end of the guide mount for position indexing and mounting insertion in a guide mount indexing and mounting slot provided therefor in a sideplate; said guide mount is mounted on sideplates in turn mounted on a bottom circuit plate including position indexing openings; and indexing projections in the form of extensions from said sideplates provided with guide mount and sideplate assemblies for precise position indexing of said guide mount and sideplate assemblies upon index and mounting insertion of said index projections into said indexing openings of said bottom circuit plate.
2. The circuit board edge guide mount of claim 1 wherein, said second index means is a bottom tab with an index opening for clipping said bottom tab over one of said indexing projections of a sideplate for close indexing and mechanical fastening of the guide mount on a sideplate.
3. The circuit board edge guide mount of claim 2 wherein, said indexing projections are tang extensions; and with the tang extensions in tapered form.
Description:
This invention relates in general to retainer racks or holders for printed circuit boards, and in particular, to a circuit card (or board) guide for receiving and guiding edges of a board or card being inserted for connection with blind connectors and the long term mounting of such boards or cards in equipment card racks or boxes.
Electronic circuit and component mounting structures in the form of circuit cards and boards have been faced with problems of proper alignment and encounter many other problems particularly when a plurality of such boards are inserted in a card rack or box to form an equipment box or module. Alignment of boards during insertion is particularly important with proper guiding of mating connectors a must, and this requires a prerequisite degree of care and skill in effectively funneling one connector into the engagement area of its mate. Further, with many equipments, the space limitations imposed on funneling devices in the instant case card (or board) guides is quite severe. Also among the problems faced are acceleration forces incumbent with some installation environments along with, in many mounting schemes, unacceptable vibration and resonance amplification rattling. It is, therefore, a principal object of this invention to provide a circuit card (or board) guide and mount enabling close connector alignment and insertion mating, occupying minimal space, with sufficient strength as a mount to adequately resist shock and vibration loading, and that eliminates rattling with the cards snugly and securely supported.
A further object is to provide such a card guide and mount capable of repeated insertion and removal of cards (or boards) without any material adverse diminution of the initial guide and mount capabilities through a greatly extended service life.
Features of this invention useful in accomplishing the above objects include a guide mount used by pairs one on each of the inner walls for each board of two spaced parallel sideplates for mounting of circuit boards traversing the space between the sideplates. It is guide mount providing close connector alignment and guided insertion mating, that occupies minimal space, optimizes circuit board spacing factors, and has sufficient resilient holding mount force and mounting strength to generally quite adequately resist shock and vibration loading and minimize, if not eliminate, rattling of cards or boards mounted thereby Each guide mount includes an upper card edge insertion guiding ramped throat, and a back portion with indexing structure at both ends. It is a guide mount made of relatively thin, highly resiliently flexible yet strong material, for example, thin beryllium copper generally less than 100 th of an inch of thickness with opposite sidewalls formed to extend upward from the back portion thereof in relatively large inwardly directing parallel radius curved portions for minimized stress concentrations and long service life as a mount with, in some cases, repeated insertion and extraction of circuit cards. The sidewalls also include a more sharply curved reverse bend outwardly from the larger curved portions to advantageously present opposing parallel inner radius rounded edges to clamp opposite sides of a circuit card edge in the desired mounting thereof. An adhesive is used between the back portion of each card guide mount and the respective inner wall of the two spaced parallel sideplates in maintaining structural integrity and to provide the mounting strength required through an extended service life with repeated insertion and withdrawal of circuit boards or cards.
Specific embodiments representing what are presently regarded as the best modes for carrying out the invention are illustrated in the accompanying drawings.
In the drawings:
FIG. 1 represents a perspective view of a circuit board receiving rack with card (or board) mounting sideplates, equipped with circuit board edge guide mounts, mounted on a bottom circuit connector plane plate;
FIG. 2, a partial cutaway view showing a circuit board in a partially guide inserted state with a connector box supported in proper alignment with connector pins projecting from the bottom circuit connector plane plate;
FIG. 3, an enlarged exploded detail view of one sideplate, a circuit board, and the board edge guide-mount embodiment of FIGS. 1 and 2;
FIG. 4, another board edge guide-mount embodiment; and,
FIG. 5, still another board edge guide-mount embodiment.
Referring to the drawings: the card or board retainer rack or holder box 10 of FIGS. 1, 2, and 3 includes a bottom circuit connector plane plate 11 and spaced parallel sideplates 12A and 12B that are mounted thereon to form the U-shaped box 10 therewith. Other than tang projections 13 of sideplates 12A and 12B that are received in openings 14 of bottom plate 11, the mounting details of the sideplates 12A and 12B to the bottom plate 11 to structurally form the U-shaped box 10 are of a conventional nature and not shown. Edge guide mounts 15 are mounted on the inner facing walls 16 of the spaced parallel side plates 12A and 12B in precisely located positions and closely controlled orientation for receiving, guiding, and providing long term mounting of respective edges 17A and 17B of circuit cards or boards 18 as they are inserted or removed and while mounted fully inserted in place. The boards 18 are shown to include connector boxes 19 for mating connection with connector pins 20 mounted to project vertically upward from the top of bottom plate 11.
Please note that the tank projections 13 of the sideplates 12A and 12B are inserted through alignment openings 21 in tabs 22 of the respective guide mounts 15 and any additional projecting overlapping ears 23 of tabs 22, if any, may be bent up the outside of the sideplates 12A and 12B as shown in FIG. 1. This construction with the tabs 22 clipped over tank projections 13 advantageously provides close indexing for the guide mounts 15 and also mechanical fastening therefor. Further, with the tang projections 13 being received in carefully and accurately located openings 14 of the bottom plate 11, the sideplates 12A and 12B are properly positioned relative to the bottom plate 11 with the guide mounts 15 in proper position on the sideplates for guiding boards 18 to fully inserted position in the holder box 10 and while being inserted for proper connector mating between connector boxes 19 and connector pins 20. Tabs 24 at the upper ends of guide mounts 15 are inserted through index slot openings 25 of the sideplates 12A and 12B for further close indexing and mechanical fastening of the guide mounts 15 to the sideplates 12A and 12B. An adhesive such as EC2214 Hi-Flex (005-1609-00) is also used to glue the backs 26 of the guide mounts 15 to the inner walls 16 of the side plates 12A and 12B, and with the guide mounts 15 having been formed from beryllium copper sheeting approximately 0.0060 inches thick advantageously thereby attaining a desired balance of resiliency in deformation and mounting strength. Please note, however, that other materials could be used both for the guide mounts 15 themselves, and also as adhesive in the mountings to the side plates and in some instances solder could be the adhesive.
The upper inwardly formed over edges 27 of the sideplates 12A and 12B are provided with oversize slot openings 28 in general alignment with the top throat ends 29 of the respective guide mounts 15 for easy insertion of card or board edges 17A or 17B to the top throat ends 29 of guide mounts 15. For optimized ease and reliability in guided insertion of card or board edges 17A and 17B to the top throat ends 29, guide mounts 15 are provided with bent over upper opposite side corners 30 angled advantageously for ramp guided easy card or board edge insertion. A further aid to easy board insertion is the top radius rounded edge 31 transition from the back base portion 32 of the guide mounts 15 to tabs 24 as compared to sharp upper edges existent with some other card mounting guides. Each guide mount 15 is provided with opposite sidewalls 33 and 34 formed to extend outwardly from the back base portion 32 thereof and from the respective inner facing wall of a sideplate 12A and 12B with an inwardly curving relatively large radius portion 35 for minimized stress concentration and optimized resilient deflection capabilities in clamping of a card or board edge. The sidewalls also include an outwardly directed bend 36 closely adjacent the outer edges 37 of the sidewalls 33 and 34 in order that a card or board edge 17A or 17B mounted therein be advantageously clamped between opposing parallel inner radius rounded edges 38 of the sidewall bends 36 rather than disadvantageously between sharp outer clamp edges.
Referring now to the guide mount 15' embodiment of FIG. 4 portions thereof the same as with the embodiment of FIGS. 1, 2, and 3 are numbered the same as a matter of convenience and this is done also with the embodiment of FIG. 5. With the approach of FIG. 4, tang extensions 13' from the guide mounts 15' themselves replace the tangs 13 of the side plates 12A and 12B of FIGS. 1, 2, and 3 for alignment positioning of the guide mounts 15' and the sideplates they are mounted on.
The guide mount 15" embodiment of FIG. 5 is quite similar to the embodiment of FIG. 4 with, however, the integral tang extension 13" being a roll formed and tapered tang extension of guide mount 15" in place of the flat tang extension 13' of guide mount 15' of FIG. 4. Please note that with some racks or boxes the side plates 12A and 12B are replaced with side plates having an outward extending formed over upper edge in place of inwardly extended formed over edges 27 with slot openings 28.
Thus, there is hereby provided a card guide mount resiliently gripping opposite sides of a circuit card or board edge with the mount used in pairs to mount opposite edges of cards or boards traversing the space between spaced parallel side plates mounting the circuit board guide mounts. The circuit board guide mounts are advantageously particularly adapted for guiding the insertion of and full inserted movement of boards, and for the proper mating insertion connection of blind connectors between connector elements mounted on boards and mating connector elements on a circuit connector plane plate also serving as a mount for the spaced parallel side plates. It is a guide mount structure substantially eliminating vibration resonance and rattle encountered with some other circuit board guide and mount structures while permitting considerably improved closer spacing of cards and boards and permits use of a greater range of card and board size than with many mounts presently in use. Further, positive mechanical alignment is advantageously assured for the card guide mounts at the bottom or circuit connector plane plate ends thereof and also for the spaced parallel side plates carrying the card guide mounts.
Whereas this invention is here illustrated and described with respect to several embodiments thereof, it should be realized that various changes may be made without departing from the essential contributions to the art made by the teachings hereof.