US 3808589 A
Electric contact maker made of a metal strip and designed to be inserted in an insulating frame comprising guiding grooves for the opposite edges of the strip.
Claims available in
Description (OCR text may contain errors)
United States Patent 1191 Bonhomme [4 1 Apr. 30, 1974 1 ELECTRIC CONTACT MAKERS AND 3,052,867 9/1962 Rogoff 339/217 5 CONNECTORS FITTED WITH SUCH I 3,693,134 9/1972 Trevisiol 339/59 M DEVICES FOREIGN PATENTS OR APPLICATIONS  inventor: Francois Robert Bonhomme, 1,330,195 5/1963 France 339/217 5 Saint-Cloud, France  Assignee: Connectronics Corporation, New Primary Examiner 30bby y York, NY Assistant Examiner-Robert A. Hafer Attorney, Agent, or FirmWaters, Roditi, Schwartz &  Filed: Apr. 6, 1972 Nissen  Appl. No.: 241,528
- 57 ABSTRACT  339/217 339/17 339/176 Electric contact maker made of a metal strip and de- 339/258 R signed to be inserted in an insulating frame comprising [51 1 Int. Cl "01! 9/08 g g grooves for the pp i edges f the Strip.  Field of Search 339/217 S, 252, 256, 258,
The part of the strip having said edges includes a 339/259, 176 MP, 17 L narrower zone from which a longitudinal tongue has [561 CM 3112:2212;121:2:1121112'11 92 I? 2:31,? UNITED STATES PATENTS free ehds' 6 g e n r 3,697,926 /1972 Krafthefer 339/17 L 3,626,361 12/1971 Bonhomme 339/217 S 9 Claims, 3 Drawing Figures 1 7 Q E\1\1\ ()6 J21 1 3a 65 f I l Q a] h 5;,
ELECTRIC CONTACT MAKERS AND CONNECTORS FITTED WITH SUCH DEVICES frame, the segment being cut out in such a way as to form at least one flexible longitudinal tongue designed to rest against at least one longitudinal support surface provided in the frame; the abovesaid part of the strip, the edges of which are designed to be inserted in the above-mentioned guiding grooves adjoining a connecting portion of the strip on one side, and on the other a flexible loop made to ensure electric contact with a conducting surface of the contacting element.
It is an object of the invention to make the such electric contact makers fulfil the various exigencies of practice better than hitherto, and, in particular to enable economical manufacture and high safety in use.
According to the invention, an electric contact I maker of the type described is characterised by the fact that the above part of the strip, having edges made to be inserted in the guiding grooves of the insulating support includes a narrower zone from which a longitudinal tongue has been cutout; this zone is extended by means of the flexible loop, which loop has a free end and is cut out so as to have on the one hand two lateral strips meeting at the free end of the loop, and on the other hand a counter-tongue having a free tip at the opposite end to the free end of the loop and which approaches said tongue so as to contact the latter, the counter-tongue pushing up against the frame thereby contributing to the locking of the contacting element in the support.
Preferably, the narrower zone, from which the tongue has been cut out, is displaced in relation to the edges designed to be guided by the grooves of the insulating frame, on the side opposite the free end of the flexible loop.
Advantageously the abovesaid part of the segment, in the area where the edges are provided, is thicker than the area from which the tongue and the flexible loop have been cut out- Preferably this thickness of the area in which said edges are provided is slightly greater than the useful height of the grooves, so that the contacting element must be forced into these grooves.
The invention also relates to electrical connectors characterised by the combination of an insulating frame and at least one electric contact maker such as defined above.
Apart from the features described above, the invention consists of certain other features which are used preferably at the same time and which will be more explicitly considered below with regard to a preferred embodiment of the invention, which will now be described in more detail, with referenceto the attached drawings, but which is in no way limiting.
FIG. 1 of these drawings shows, in perspective, with according to the invention.
FIG. 2 shows in cross-section an insulating support frame fitted with an electric contact maker similar to the one in FIG. 1.
Lastly, FIG. 3 shows in perspective, with parts detached, a housing of the insulating support frame for the electric contact maker.
Referring to FIG. 1 it is seen that the electric contact maker-1 is made up of a metal conducting strip or segment with a part 3 in which an area 3a includes edges B designed to be guided by the grooves 35 (see FIGS. 2 and 3), cut into an insulating frame 28. The metal segment 3 adjoins the socket on one side, extending the area 3a, and on the other a flexible loop 5 ensuring electric contact with a conducting surface, in particular a printed circuit card.
Part 3 of the segment includes a Zone 3b narrower than the area 3a. A longitudinal tongue 6 has been cut out of zone 3b. This tongue is designed to abut against one or several longitudinal supporting surfaces provided in the insulating frame 28, and which will be discussed below. Zbne 3b extends the area 3a while the flexible loop 5 extends zone 3b.
The loop 5 is open and has a longitudinal section curved back in the shape of a hook, as is obvious from the drawings. The free end 5a of the loop 5 is lengthwise substantially at the level of the nearest part of the area 3a to zone 3b. The mean plane of the end 5a is substantially parallel to the mean plane of the area 3a.
The above loop 5 has itself been cut out in such a way as to form on the one hand two lateral strips l5, 16, extending the strips of the zone 3b situated on either side of the tongue 6, and on the other hand a countertongue 60, whose free tip 61, which is at the opposite end of the extremity 5a of the loop, is brought back close so as to contact the tongue 6. The tongue 6 and the counter-tongue 60 have a general rectangular shape, the mean plane of the'tongue 6 being substantially parallel to that of area 3a, while the mean plane of the counter-tongue 60 is sloping relative to that of the area 3a.
Advantageously, the free end of the tongue 6 and the free end 61 of the counter-tongue 60 are concave, in the same direction as the loop 5. The lateral strips 15 and 16 form two simple loops situated on either side of the counter-tongue 60 and meeting at the free end 5a of the loop 5. The lateral strips 15 and 16 are separated by a continuous slot F, the extended length of when extended is substantially equal to the sum of the lengths of tongue 6 and counter-tongue 60. The latter, near its end 61, traverses the slot F.
The tip 61 of the counter-tongue 60, as shown in FIG. 2, is designed to push the tongue 6 up against the insulating frame 28 and to facilitate the locking of the contact maker 1 into the frame.
The other end 61a of the counter-tongue 60 joins the free end 5a of the loop 5, the counter-tongue 60 (like the tongue 6) being cut out on three sides only. The metal has been bent at the level of the end 61a so that the tip 61 touches tongue 6.
Preferably, the area 3a is of greater thickness e than the zone 3b and the loop 5, the thickness e of the area 3a being itself slightly greater than the useful height 41 (FIG. 2) of the grooves 35 of the frame 28. In this way the area 3a of the contact maker must be forced into the grooves 35 and the transverse support in relation to the grooves 35 of the contact maker is effected automatically. The area 3a may be bent in order to afford give it, while relaxed, an overall thickness greater than the useful height of the grooves. In the case of the embodiment of FIG. 1, the area 30 is substantially flat.
It is also preferable that the zone 3b be displaced in relation to the area 30 and the edges B by a distance f on the opposite side to the end 50 of the flexible loop so that a shoulder 3c is formed at the junction between the area 3a and the zone 3b.
To ensure the lengthwise locking of the contact maker in the frame 28, two protrusions 62, 63, adapted to rest against the longitudinal supporting surfaces 64, 65 (FIGS. 2 and 3), are provided in the frame 28, on each side of the tongue 6.
The protrusions 62, 63 are made up of two flaps from the tongue 6, formed on one side by a cut made transversally, approximately halfway across the width of this tongue.
These protrusions 62, 63 are separated from one another lengthwise and are in'between the above mentioned cuts. The protrusions are obtained by folding back and lifting up an area approximately triangular, on the side of the tongue 6 opposite the loop 5.
The longitudinal supporting surfaces 64, 65 (FIGS. 2 and 3) are made up of the longitudinal ends of the bosses 66, 67 provided on part 68 of the surface of'the frame turned towards the tongue 6.
Each of the bosses 66, 67 extends transversally, as shown by the double arrow T in FIG. 3, over a fraction of the width 1 of this part 68, on each side of the latter. The sum of the widths of the bosses 66, 67 is smaller or equal to 1, the width of each boss being preferably equal to the half of l.
The bosses 66, 67 extend lengthwise, starting from each end of the frame 28 and the lengths of the bosses are such that the internal longitudinal ends 64, 65 of these bosses are separated from each other by a longitudinal distance g (FIG. 2) so that there exists in the casing 31 of the contact maker 1, provided in the frame 28, a space R free of any boss, into which the protrusions 62, 63 of the tongue 6 fit.
The distance g (FIG. 2) between the longitudinal supporting surfaces 64, 65 is equal or slightly less than the distance separating the transversal sides of the protrusions 62, 63, designed to come into abutment with the abovesaid longitudinal supporting surfaces, so that the stopping of the contact maker 1 in the frame 28 is ensured without substantial longitudinal play.
The frame 28, into which contact makers such as l are designed to be fitted, comprises series of housings 31 of substantially rectangular transversal section, separated by partitions 32 and open at their two ends. These housings and these partitions form two series symmetrical in relation to the plane of line 29, corresponding to the mean plane of a printed circuit card designed to be introduced into the space E between these series of partitions. The check or stop 33 provided on the frame 28 is designed to limit the admission of the printed circuit card. This check 33 includes clearances 33a, of perpendicular transversal section, turned towards the space E and adapted to take the free end a of the loop 5 of a contact maker.
Advantageously the free end 5a of the flexible loop 5 is situated, when relaxed, at a distance H (FIG. 1) from the middle axis of the area 3a, greater than the distance (FIG. '2) separating the middle axis of a groove 35 from the surface of the gap 33a against which the end 5a will abut. Under these conditions, in order to cause the device to occupy the position shown in FIG. 2, a compressing force must be exerted on the loop 5, which, because of its elasticity, remains in abutment against the surface 33a.
To fix a contact maker 1 in a housing 31 of the frame 28, this contact maker may be introduced, correctly oriented, through one of the two open ends of the housing 31, that is to say as depicted in FIG. 2; one can operate from the right or left of the frame 28.
When the introducing is effected from the right of the frame, the contact maker 1 is oriented in such a way that the loop and the tongue 6 are introduced first into the housing 31, the free end 5a being turned towards the mean plane of the frame 28. Care should be taken to insert the edges of the area 3a in the grooves 35.
The free end 5a must must be lifted up to pass the check 33 and because of the elasticity of loop 5, the end 5a returns automatically into the gap 33a. The compression on loop 5 is self-effected.
When the protrusions 62, 63 come into line with the free space R, the tongue 6 moves away from loop 5 and said protrusions, by co-operation with the longitudinal supporting surfaces 64, 65, and ensure the fastening of the contact maker 1 in the frame 28.
If the introducing had been effected from the left of FIG. 2, a wedge would have been set up in the free space E, designed to press down on loop 5 and to enable correct placing of the end 5a in the gap 33a.
The removal of the contact maker 1 from the frame 28 can be effected, like the introduction, from either end of the housing 31, that is, from the front or the back of the connector, frame 28. To effect this removal, one must on the one hand disengage the protrusions 62, 63 from the space R, for example with the aid of a suitable tool, introduced between the tongue 6 and the frame 28, and on the other hand exert an extraction force on the contact maker 1 either towards the right or left of FIG. 2. It must be noted that, when one wants to remove the contact maker 1 towards the right of FIG. 2, a wedge must first be introduced into the space E enabling the loop 5 to be sufficiently compressed so that the free end 5a is freed transversally from the check 33 and does not hinder the removal of the contact maker 1 towards the right of FIG. 2.
As can be seen in FIG. 2, the curved end of the counter-tongue is supported against the tongue 6, in the latter zone of which there are the protrusions 62, 63. The counter-tongue 60 acts as a brace in being urged against the free end 5a, and as a result, the check 33, to exert a holding force on the tongue 6, which holding force contributes to the safety of the longitudinal locking of the contact maker 1 in frame 28.
According to a modification, the co-operation of tongue 6 and frame 28 ensures the locking of contact maker 1 in frame 28 only in a direction which corresponds, for FIG. 2, to the direction going from right to left. This locking will be ensured, for example, by the protrusion 62 acting in conjunction with the supporting surface 64. Locking in the other direction that is for FIG. 2 from left to right, will not be ensured either by a protrusion such as 63 acting in conjunction with a surface 65 but by the shoulder 30 acting in conjunction with a boss (not shown) provided on the frame 28. According to this modification the fixing of the contact maker 1, in the frame 28 is only possible in one direction, from left to right for FIG. 2; it is the same for the removal of contact maker 1, from the frame 28 which is only possible in the opposite direction to the one just considered.
The frame 28, shown in FIG. 2, is adapted to receive two series of contact makers 1, symmetrical in relation to the plane of line 29. Because the free ends 5a of the contact makers are in abutment against the surfaces of the gaps 33a as a result of the compression of the loop 5, the spacing between the zones of the two contact makers 1, symmetrical with respect to the plane of line 29, is fully pre-determined and equal to the thickness of the check 33 at the level of the gaps 33a.
The quality of the electric contact obtained between the contact maker 1 and a printed circuit card introduced into space E, is safe and may be reproduced exactly. Indeed, not only is contact obtained by means of two lateral strips 15, 16 constituting a sort of double contact segment, but the counter-tongue 60 forms, as seen in FIG. 2, a sort of deformable polygon with loop 5. The counter-tongue 60, which forms one of the sides of this polygon, exerts on the end 5a a force transmitted to the lateral strips 15, 16 which is added to that due to the compression of the flexible loop 5 and facilitates the contact of said loop with the printed circuit card. Besides which, the counter-tongue, by means of its tip 61, contributes to the locking of the contact maker 1 into the frame 28 while maintaining tongue 6 in cooperation with this frame.
The two lateral strips 15, 16 of loop 5 are extremely independant of each other, since the opening F which separates these strips is very long and practically equal to the sum of the lengths of the counter-tongue 60 and the tongue 6. This independence of the strips and 16 facilitates good contact.
When the printed circuit card has been introduced into the space E of FIG. 2, if the mean plane of this card is sloping in relation to the mean plane of line 29, of the connector, the point of thrust of the tip 61 of the counter-tongue 60, against tongue 6, will be displaced, which ensures constant contact between the printed circuit card and the flexible loop 5 over substantially the whole length of the portion of the latter which is parallel to the plane of the line 29 and turned towards the space E. I
The counter tongue 60 exerts its effect on the loop 5 as soon as the printed circuit card has been introduced into the space E, for the point of contact of the tip 61 against the tongue 6 is situated longitudinally at the level of the part of loop 5 which first comes into contact with the printed circuit card.
Another advantage of a connector constructed according to the invention to be pointed out is that the length of the loop 6 when extended is shorter than when the latter is shaped like an ellipse, and that the necessary tools to cut this loop into two simple loops I5 and 16 are of smaller dimensions and are less expensive. This lowering of the cost of production results on the one hand, in a reduction of the cost of the equipment necessary for the production of the contactor and on the other hand, in a reduction of the raw material necessary for its production.
It must also be emphasised that the frame 28 may be cast very easily means of the advantageous placing of the bosses 66, 67, the ends of which constitute the longitudinal supporting surfaces of the contact maker 1. In fact one has merely to introduce into the mould through a suitable end of the housing 31, rods which will prevent the material from spreading during casting, on the one hand between the longitudinal end 65 of the boss 67 and the open end of the housing 31 out of which comes the boss 66, and on the other hand, between the end 64 of the boss 66 and the open end of the housing 31 out of which comes the boss 67. The removal of these rods after casting is easily effected.
As a result of which, an electric contact maker is obtained, whose fixing in the insulating frame is safe and whose production is economical. The forces exerted by this device on a conducting surface, such as that of a printed circuit card, are able to be reproduced mainly because of the action of the counter-tongue.
What is claimed is: I
1. An electric contact maker for forming a connector when inserted in an insulating support frame adapted to receive a contacting element, said contact maker comprising a metal strip including a first portion having .edges adapted to be inserted in guiding grooves provided in the insulating frame, and a second portion, narrower than the first, and extending in continuation thereof, said second portion including a flexible loop to ensure electrical contact with a conducting surface of the contacting element, and a connecting portion joining the loop to the first portion, said loop having a terminal free end remote from the connection thereof to said connecting portion, said loop being provided with a cut-out to form two lateral strips joined together at said free end of the loop, a flexible longitudinal tongue adapted to abut at least one longitudinal supporting surface provided on the frame, and a counter-tongue having a free end in contact with the first said tongue to press the same against the frame, thereby contributing to the locking of the contact maker in the frame, said free end of said loop lying in a plane extending substantially parallel to said first portion to ensure constant contact over substantially the entire length of said free end with the contacting element.
2. Electric contact maker according to claim 1, wherein said second portion is displaced in relation to the edges of said first portion.
3. An electric contact maker according to claim 1 wherein said first portion is thicker than said second portion.
4. Electric contact maker according to claim 3, wherein the thickness of said first portion is greater than the useful height of the insulating frame so that the contact maker must be inserted by force into said grooves.
5. Electric contact maker according to claim 12, wherein the longitudinal tongue comprises, on either side, a protrusion adapted to rest against an adjoining longitudinal supporting surface provided in the insulating frame.
6. Electric contact maker according to claim 5, wherein each protrusion is shaped out'of part of the tongue, bounded on one side by a cut made transversally, approximately halfway across the width of the tongue, said part being shaped so as to form said protrusion on the opposite side of the tongue to the side on which the flexible loop is situated.
7. Electric contact maker according to claim 5, wherein the counter-tongue presses against the tongue close to said protrusions.
8. Insulating frame for the contact maker according to claim 5, comprising a housing open at both ends wherein the longitudinally supporting surfaces are formed by the ends of bosses provided on part of the housing surface which is designed to turn towards the tongue, each boss extending transversally, over a fraction of the width of said part of the housing surface, on either side of the latter, the sum of the widths of the bosses being not greater than that of said part of the housing surface, said bosses extending lengthwise from each end of the frame over a fraction of the length of the latter, the length of said bosses being such that their inner ends are separated from each other so as to leave a space in the housing free of any boss in which said stop surface of the frame, in a fixed position.