US 2825037 A
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Description (OCR text may contain errors)
Feb. 25, 1958 H. H. FRENCH PRINTED-CIRCUIT CARD CLAMP Filed Feb. 4, 1955 FI'G.4
H'ARRY H. FRENCH FIG.6
ATTORNEY Unimd Patent 0 KITY' The invention described herein may be manufactured and used by or for the Government for governmental purposes without the payment of any royalty thereon.
This invention relates to mounting devices for joining printed-circuit cards at right angles.
It is a primary object of this invention to provide for secure, yet readily releasable mounting and retention of printed-circuit cards at right angles in such amanner that accidental dislodgements are prevented and cards remain in joined positions unless the mounting device is acted upon in a very specific manner.
It is a further object of this invention to make such mounting devices not only very effective but also rugged and of great simplicity so that they may be used at very low cost.
The mounting device according to the invention comprises essentially a pair of cooperating contact arms or clamps, the lower parts of which are actuated by a toggle joint capable of assuming either one of two positions, that is, an inoperative position at which time the upper portions of the clamping arms are spaced apart, and an operative position at which time the upper portions of the clamping arms are urged toward each other. From an inspection of the device shown in Figure 1 it is apparent that at the time the device is in operative position as shown by the dotted lines the straight line distance between the extremities of the toggle arms is greater than the straight line distance between the extremities of the toggle arms when the toggle joint is in inoperative position as shown by the solid lines. These contact clamps are inserted into one of the two slots formed by a crossshaped opening provided in a first printed-circuit card in such a manner that the lower parts of the two movably connected contact clamps will extend below the card. The second printed-circuit card which is to be connected to the first card at right angles thereto is inserted in between the two cooperating arms or clamps and pushed through the other slot of the cross-shaped opening. When the bottom edge of the second card is forced into engagement with the toggle joint, the toggle joint is upset from the inoperative position to the operative position shown in dotted lines. Such action will urge the lower portions of the clamp members apart for the reasons indicated above with the first card functioning as a fulcrum in effecting the inward movement of the upper portion clamping members. The edge of the second card, by exerting pressure on the toggle that connects the contact clamps pushes their lower parts apart so that due to the lever action of the clamps their upper ends are pressed against the second card thus holding or locking it in position. To insure the lever action the clamps are provided with appropriate notches to form opposing seating shoulders which engage the slot in the main card, allowing the edges of the latter to act as a fulcrum for the lever action exerted by the clamps.
The invention will become more apparent from the following specification referring to the accompanying drawing in which:
' 'ice Fig. 1 is an elevation partly in section of the mounting device according to the invention.
Fig. 2is a perspective view of one contact clamp.
Fig. 3 is a plan view in section along line 3-3 of Fig. 1 showing the cross-shaped opening in the base of the main card.
Fig. 4 shows an elevational view of a modification of the lower part of the two clamps connected by the hinge.
Fig. 5 shows in perspective a multiple mounting device with the printed-circuit cards shown partly in section.
Fig. 6 shows in perspective another embodiment of the contact clamps, and
Fig. 7 shows a detail of the clamp represented in Fig. 6.
The mounting device of Fig. 1 comprises a printedcircuit card 1 having a cross-shaped opening generally designated as 2 (Fig. 3) which has a relatively short slot 3 in which to insert the clamps or contact arms 4 (Fig. 2) and-another slot 5, transverse to slot 3. The dimensions ofslot 5 correspond to the dimensions of .a second card 6 which is to be connected at right angles with the printed-circuit card 1. To both surfaces of the cards 1 and 6 there are affixed, by any conventional method, arrays of printed circuitry designated respectively as 31 and 33. The two contact clamps 4, 4 are connected by a toggle 7 consisting of two arms 8 joined together to form an elbow-like joint as shown at 9. The two arms 8 terminate in tabs 13 that fit into holes 10 (Fig. 2) at the lower ends of the contact clamps 4. The clamps 4 are provided with notches 11 whereby the opposing seating shoulders, formed by said notches, will rest on either side of the card 1.
By inserting the second card 6 between the two cooperating arms 4 and by pushing this card through the slot 5 the lower edge of the second card 6 will exert pressure on the joint 9 of the toggle 7. The toggle 7 will be forced into the position indicated by the dotted lines at 7' whereby the straight line distance between the extremities of the toggle arms will be made greater than when the toggle is in inoperative position and thereby urge the clamps 4, 4 apart. At the same time the clamps 4, 4 are brought into the position 4, 4 as indicated in the drawing in dotted lines whereby their upper ends are pressed against the card 6 thus holding or locking it in position. In this position, the arms 4 will be urged into physical contact with the circuitry 33 of card 6 and the circuitry 31 of card 3 whereby electrical contact between said circuits will be eiiected. The lever action of the clamps 4, 4 is insured by the shoulders formed by the notches 11 which engage the ends of the slot 3 in the main card allowing the short edges 12, 12 at the end of the slot 3 to act as fulcrum for the lever action exerted by the clamps 4, 4.
Fig. 5 shows a multiple connection in which the card 26 serves four pairs of contact arms. Accordingly, the slot of the main card 21, having an array of circuitry 35 therein, includes four openings 23 for each of the four pairs of contact arms. In such multiple connections the toggle 7 is not permitted to fall below the centerline which may be attained by bending the ends 24 (Fig. 4) of the contact arms 4 upwards to a position where they prevent the arms 8 of the toggle 7 from reaching the position indicated by dotted line in Fig. 1 at 7'. To lock the card 26 in its position two clips 27 are connected to the main card 21. These clips 27 snap into perforations 28 of the inserted card 26 and hold this card 26 against the elbow toggle 7 thus forcing the lower ends of the clamps 4 apart and insuring pressure of the upper ends of said clamps against the circuitry of the card 26.
As shown in Figs. 6 and 7 the arms 4 may be provided with fingers 61 and 62 in which case the card 6 that 7 isjto be inserted atright angles into the main card l -is fabricated with small locking holes in the board of the 7 card, which locking holes are aligned with the fingers 61 and 62 to insure the locking action brought about'by Ithe action of the toggle' 7. '4 i Either pigtails 63 or pressure arms 64"(-Fi'gs'.16)jinay beattached to the contact arms; 4 to insure proper contact of the circuits to' the base card 1.3 g e The mounting device accordihg to'the invention may be used with single or double-sided cards. If doublesided' cards are'used, that is,if the circuitry is printed on both sides of a card'the hinges or at least their pivots should be made of an insulating material."
f It will be obvious to those skilled the'art that afgreat I many variations and combinations are conceivable within the scope of the present invention iasdefined in the ap pended" claims;
What is claimed is:
said clamping arms; said toggle joint having a first operative position and a second, inoperative position wherea in when said toggle is in its first operative position the 7 straight line distance between the ends oftsaid toggle arms is greater. than when saidtoggle is in its second in-' 1. In combination, first and second printed circuit 'cards having discrete printed circuits thereon, a pair of opposing electrically conductive clamping arms for ef- 'fecting electrical contact between the circuits of said cards and for supporting said cards perpendicular to each other, said clamping arms having a first pair of free ends and a second pair of ends engaged bya toggle joint; each of said arms'extending through an opening in said first card, said toggle joint having arms, the ends of which are engaged with respective discrete engaged ends'of operative position, and the 'free'ends of said clamping arms are urged into substantial engagement with each other, whereby when said second card is introduced into said opening and against said toggle joint, said jointwill be urged into its first operative position and thefree ends of said clamping arms will'be urged toward each other a to engage'and hold said second card;
a 2. A clamping device of the type 'set forth i claim 1 in whichthe clamping arms 'are'provided with means for engaging the surface of said second card:
3. A clamping device of the type set forth'in claim V wherein said last mentioned means comprises a pair of oppositely disposed shoulders formed in each of .said