US 3314040 A
Description (OCR text may contain errors)
April 11 1967 w. H. M KEE 3,314,040
ELECTRICAL CONNECTOR Filed Jan. 15, 1965 2 Sheets-Sheet 1 Inventor William. 3+. M- Kee 5 W M4.
Gite Wa April 11, 1967 w cKEE 3,314,040
ELECTRICAL CONNECTOR Filed Jan. 15, 1965 2 Sheets-Sheet 2 Egg-2 Inve ncor' William Kee B 1mm United States Patent 3,314,040 ELECTRICAL CONNECTOR Wiliiam H. McKee, West Covina, Califi, assignor to United-Carr Incorporated, Boston, Mass, a corporation of Delaware Filed Jan. 15, 1965, Ser. No. 425,697 4 Claims. (Cl. 339-75) The present invention relates to an electrical connector and more particularly it relates to an improved connector having positive force loading means to assure desired clamping engagement between the electrical connector and a circuit board inserted therein.
One of the difliculties associated with connectors for use with printed circuit boards resides in the means to secure the board Within the connector. Some connectors have. interlocking means to secure the board. Still others depend upon tight frictional engagement by providing a board receiving opening smaller than the board. In this case, however, insertion and removal of the board is very difficult and may result in damage either to the board or to the printed circuits on the board.
In accordance with the present invention 1 have provided an improved connector having force loading on the insulating body to define the clamping force necessary to securely hold the .board within the board receiving opening of the connector. .porarily to release the loading force to conveniently perrnit insertion or removal of the board into or from the connector, respectively.
It is, accordingly, a general object of the present invention to provide an improved electrical connector.
Another object of the present invention resides in the provision of an improved electrical connector having force loading means to define clamping means for anchoring a circuit board within the connector.
Still a further object of the present invention resides in the provision of an improved electrical connector with force loading means to clamp a circuit board within the connector and having means to remove the force loading.
An additional object of the present invention resides in the provision of an electrical connector having force loading means to secure a circuit board within a connector and having guide means to orient the circuit board.
The novel aspects of the present invention are set forth in the claims appended hereto. Other objects and advantages, however, will best be understood from a reading of the detailed description hereinbelow taken in connection with the accompanying drawings, in which:
FIGURE 1 is a side elevation of the connector of the present invention with a circuit board inserted in said connector;
FIGURE 2 is an end elevation of the connector of FIGURE 1;
FIGURE 3 is a top view of the connector of FIGURE 1 with the board removed and showing the result of force loading on the insulating body;
FIGURE 4 is a top view of the connector of FIGURE 3 with the circuit board inserted therein;
FIGURE 5 is an illustrative view of a tool for applying a spreading force to the ears of the jacket to remove the loading force for insertion or removal of a circuit board;
FIGURE 6 is a schematic representation of the jacket positions with i the solid lines representing the board clamping position and the dashed lines representing the loading force removal position;
FIGURE 7 is a schematic representation of the force application to the insulating body;
FIGURE 8 is a top View of the insulating body in the I further provide means temunloaded condition and in position to receive a circuit board; and,
FIGURE 9 is a fragmentary enlarged sectional view of the connector through the pin assembly area.
Referring more particularly now to FIGURE 1 of the drawings, the connector of the present invention is indicated generally at 10. As seen, the connector 10 includes a jacket 12 and an insulating body 14.
The jacket 12, in the embodiment specifically illustrated herein, is defined by two interlocking L-shaped elements 15 and 16 (seen more clearly in FIGURES 3 and 4-). Each of the elements 15 and 16 is provided with an extending guide projection 17 and '13, respectively, to receive the edges of the circuit board 20. The guides provide means for proper orientation of the circuit board with respect to the connector and further define rigid support means for said board when it is mounted in the connector 10.
Projecting fingers 22 and 24 are provided for securing the connector to a support body, if desired. Other means for such mounting may also be provided.
An insulating body 14, as seen in FIGURES 3, 4, 7 and 8, is mounted within the support jacket 12 with the jacket in supporting engagement with the walls of said insulating body. The insulating body in the embodiment specifically disclosed herein includes two L-shaped sections 26 and 28, each having a long and a short leg and which in assembled relation define a rectangular section with a central opening 3t) therein to receive a circuit board. The central opening 30 is provided with electrical contact means in spaced relation therealong and in position to mate with the electrical leads on the circuit board to be inserted therein so that a complete electrical path is defined from the printed circuit board 20 to the contacts (not shown) of the opening in the insulating body. As seen in FIGURE 1, 'a plurality of terminal posts or electrical leads 32 extend from the insulating body, one lead 32 for each contact in said body 14.
A resilient pressure pad 34 may be inserted within the opening along either side wall thereof, as seen in the dashed lines of FIGURES 3 and 4. The pressure pads 34 may be of a silicon rubber and are adapted to distribute the clamping force to the contacts of the connector. It can readily be seen that slight variation in thickness of the board or electrical contacts would prevent uniform force distribution if the pressure pads 34 were not used.
A thin strip of insulating material may be inserted be tween the walls of the insulating body and the supporting jacket. In the embodiment disclosed herein a sheet of Mylar (trademark of the Du Pont Company) is interposed in the interfacial area between the body and the walls of the jacket to further inhibit leakage and to protect the body itself.
The support jacket 12 is provided with means thereon for application of an externally applied force to spread the jacket to a position on the insulating body 14. As seen in FIGURE 1, the means noted hereinabove includes an upstanding ear-like projection 35 extending from the wall of each long leg of the L-shaped sections forming said jacket.
The eifect of the application of the clamping force on the insulating body is seen in FIGURE 3 of the drawings. As shown, the clamping force applied by the longer legs of each section of the support jacket 12- moves the unsupported section of the L-shaped sections of the insulating body inwardly. to constrict the central opening 30 defined in the body. The central portion of the longer legs of the L-shaped insulating body sections will move inwardly, as shown, due to the fact that they are not supported in this area. The stress application in this area, however, is Within the elastic limit of the insulating material and 3 upon release of the clamping force the legs will return to the condition indicated in FIGURE 8.
With the insulating body 14 in the condition shown in FIGURE 3 of the drawings, assembly of a circuit board in the connector would probably not be feasible. Generally, the circuit board will be made with a blunt leading edge of the same thickness as the remainder of the board. It can readily be seen that the board cannot move into the restricted opening 30 defined in the insulating body 14 when in the loaded condition.
To facilitate assembly of the circuit board with the insulating body the body must be unloaded and the clamping force exerted by the support jacket 12 must be relieved. This may be done with a spreading tool of the type illustrated in FIGURE of the drawings. As shown, an application of force F at the handle ends 36 and 36' will pivot the jaws 38 about the pivot pin 40 in the reverse direction D from the direction of application of the force F.
The terminal portions of the jaws 38 are inserted inboard the ear-like projections 35 of the jacket sections 15 and 16 and a force F applied thereto. The jaws, upon the application of force F to the handles 36 and 36 will move outwardly in direction D to unload the clamping force otherwise exerted by the jacket 12 and to permit the insulating body 14 to flex outwardly to its static unloaded position where the central opening 30 is sufficiently large to permit easy insertion of the circuit board 20 of the assembly. When the circuit board is fully inserted within the opening of the insulating body, the force F is removed and the spreader tool is withdrawn. The clamping force is reapplied to the insulating body 14 by the jacket 12 and the circuit board 26 is securely physically retained within the opening 30 with the leads of said board in electrical contact with the contacts (not shown) of the insulating body. It can readily be seen that the amount of force F to be applied to the handles 36 and 36 will depend in part upon the magnitude of the clamping force exerted by the support jacket 12 and the mechanical advantage in the spreading tool as defined by the length ratio between the axis of the pivot pin 40 and the area of contact of the jaws 38 with the ear-like projections and the axis of the pivot pin 40 and the area of application of force F upon the handles 36 and 36'.
The alternate positions of the supporting jacket 12 are shown schematically in FIGURE 6 of the drawings. The solid line position of FIGURE 6 illustrates the normal position of the jacket, in which position the jacket will exert a clamping force on the insulating body. The dashed lines of FIGURE 6 illustrate the spread position of the jacket 12 in which position the clamping load will be removed from the insulating body and the opening 30 will define a lateral dimension adequate for easy insertion of the circuit board 20. With the support jacket 12 in the position shown by the solid lines of FIGURE 6 the insulating body 14 of the connector will be in the position schematically represented in FIGURE 7 with the longer legs of the insulating sections 26 and 28 being moved toward each other. With the support jacket 12 in the position shown by the dashed lines of FIGURE 6, the clamping load will be removed from the insulating body 14 and the body will assume its static unloaded position as shown schematically in FIGURE 8 of the drawings.
As seen in FIGURE 9, the L-shaped sections 26 and 28 of the insulating body 14 are maintained, in part, in aligned and assembled relation by the pins 42 which extend through axially aligned openings in the juxtaposed portions of the sections 26 and 28. The pins 42 are disposed within similar openings at each end of the assembled sections 26 and 28 although only one end is shown in the fragmentary sections view of FIGURE 9. The opening 44- in L-shaped sections 26 defines a larger diameter recess 46 at the inboard face thereof to receive the shoulder 48 of the pin 42. The shoulder 48 serves to 4 orient the pin 4-2 axially within the openings of the mating insulating bodies. The terminals of the pins 42 extend into openings in the walls of the jacket 12 as defined at the base of the generally U-shaped cut-outs 50, as seen more clearly in FIGURE 1 of the drawings. The island portions 52 of the U-shaped cut-outs define force fingers or clamping bars to provide means for the application of uniform loading along the wall of the insulating body. These fingers extend along either side of the center section of the jacket 12 and define a more uniform clamping force on the insulating body 14. Without these fingers it is probable that the clamping force would be strongest in the central area of the longer legs of the L-shaped sections 26 and 28 and would be distributed therebeyond only through stress distribution within the material. This could result in a significant concentration of stress in the center section of the body 14- and possibly would lead to a condition where insuflicient stress would be applied at the outer portions of the opening 14 to assure full uniform contact between the contacts of the body 14 and the leads on the circuit board 20. Thus, the fingers 52 help to distribute the load on the body as applied by the jacket 12 and provide for a more uniform loading by the clamping action of the jacket 12.
As schematically represented in FIGURE 7 of the drawings, the major application of clamping force on the insulating body 14 by the jacket 12 occurs in the area adjacent the center of the body 14. The loading is characteristic of a beam loaded at one area thereof with the beam flexing under load. If the flanges 52 were not present on the jacket 12 the load could be of an isolated nature and applied only in the center section as indicated by the brackets A and A. This type of loading with its isolated concentration of stress on the body 14 may not be desirable for the reasons noted above. With the fingers 52 on the jacket 12, however, the application of clamping force to the body is spread over a larger area as indicated by the brackets B and B. The primary loading is still in the central area of the body 14 due to the applications of that load in the central area by the formed jacket sections 15 and 16. However, the greatest load resisting force will occur in this area due to the unsupported nature of the long legs of the sections 26 and 28. Thus, the major force concentration must be in the center area of the long legs with the clamping force diminishing as the supported or fixed terminals of the longer legs are approached. This load distribution thus provides a more uniform force distribution along the entire wall of the insulating body to assure full uniform physical engagement between the body and the board and to assure good electrical contact along the entire board.
While I have disclosed a specific embodiment of the present invention it should be understood that alternative embodiments and structures may be devised that depart from the illustrative form expressly described. It is not intended that the invention disclosed herein be limited strictly to the embodiment disclosed. I intend by the claims appended hereto to include the specific embodiment disclosed and such alternative embodiments and structures as are included within the true spirit and scope thereof.
What I desire to secure by Letters Patent of the United States, is:
1. An improved electrical connector to receive a printed circuit board, or the like, in positive frictional and electrical engagement therewith comprising, in combination:
an insulating body defining a circuit board receiving opening, the opening in said body having electrical contact means therein to mate with the leads on the circuit board when mounted in said body;
a support jacket mounted about the walls of said insulating body, opposed legs of said jacket being formed such that a clamping force is exerted on the insulating body to bias the insulating body to a more compact condition thereby to narrow the opening in said body in loaded condition to a lateral dimension less than the thickness of the circuit board without the circuit board in said opening, said jacket having means thereon for application of an externally apof each said section being formed such that when the sections are in interlocked relation about the insulating body an inward clamping force is exerted on the insulating body to resiliently narrow the opening plied force to relieve the loaded condition on the in- 5 therein to a position where the opening is of smaller sulating body and to permit the body to assume its lateral dimension when loaded than when unloaded, static unloaded condition for ease of insertion of the said jacket sections each having means thereon for circuit board, whereby upon removal of said exapplication of an externally applied force to relieve ternally applied force the jacket again applies a the loaded condition on the insulating body and to clamping force to said insulating body and forces permit the insulating body to resiliently return to the the body and contact means in the opening thereof into intimate electrical and physical engagement with said circuit board.
unloaded condition for ease of insertion of the circuit board, whereby upon removal of said externally applied force the jacket clamps the insulating body 2. An improved electrical connector to receive a printed circuit board, or the like, in positive frictional and electrical engagement therewith comprising, in combination:
an insulating body defining a circuit board receiving opening, said opening in unloaded condition being and contacts therein into intimate electrical and physical engagement with said circuit board.
4. An improved electrical connector to receive a printed circuit board, or the like, in positive frictional engagement therewith comprising:
an insulating body having a circuit board receiving slightly less in lateral dimension than the board opening therein, the opening in the unloaded condithickness, the opening in said body further having tion of the body being less in lateral dimension than electrical contact means therein to mate with the the thickness of the board but not sufiiciently less to leads on the circuit board when mounted in said provide the desired frictional engagement between body; the body and the board to define a secure interconsupport jacket mounted about the walls of said innection, the opening in said insulating body having sulatrng body, said jacket comprised of two mterelectrical leads in mating relation to the printed cirlocking generally L-shaped sections, the opposed cuit leads on said circuit board; legs of said sections, when in interlocking relation a jacket open at its ends and enveloping the outer walls about the insulating body, being formed such that a of the insulating body, said jacket exerting a clampclamping force is exerted on the insulating body to ing force on the insulating body to deflect said body bias the insulatirig body intodafimoe l:ompact COIidland to reitnct salild openiriigdto a dsmallerflaltergl 511- tion to narrowt e opening e no t erein to a at mensiont an int e un oa e con ition o t e o y, eral dimension significantly smaller when loaded than said jacket having spaced apart guide legs to receive when unloaded, said jacket sections each having the edges of the circuit board, said jacket further means thereon for application of an externally aphaving projections thereon defining means for appliplied force to relieve the loaded condition on the cation of an externally applied spreading force to insulating body and to permit the body to resiliently relieve the jacket applied force on the insulating body return to the unloaded condition for ease of insertion and permit easy insertion of the circuit board, re-
' l f t ll 1 d l t Z233aiij llllii firl llijiciftfialifffii $3555 40 313?; Sill itlj ini illiidiig liffiiir el fifi ing body and contacts therein into intimate electrical tional engagement between the insulating body and and physical engagement with said circuit board. the circuit board.
3. An improved electrical connector to receive a printed circuit board, or the like, in positive frictional References Cllted y the Examine! engagement therewith comprising, in combination: U I S A S PA N An insulating body defining a circuit board receiving 2936 439 5/1960 Murphy pf 531d P? m t ulilloaded condltlon 2 94 033 7 19 0 Wirth 339 17 X being sllghtly less in lateral dimension than the board 3 037 181 5/1962 L eshner 339-17 thickness, the openlng in said body further having 3,076,166 1/1963 Raddm 339-17 electrical contact means therein to mate with the 3107961 10/1963 H h t 1 339 17 leads on the circuit board when mounted in said a n e 3,124,405 3/1964 Massa 339-60 body;
a support jacket to envelop the outer walls of the body, EDWARD ALLEN Primary Emmimn said jacket comprised of two interlocking L-shaped sections having a long and a short leg, the long leg DONALD MILLER, AS81814"! Examiner