US3923361A

US3923361A - Electrical connector and circuit board mounting system

Info

Publication number: US3923361A
Application number: US503216A
Authority: US
Inventors: Harold Rosen
Original assignee: Sanders Associates Inc
Current assignee: Interflex Corp
Priority date: 1974-09-05
Filing date: 1974-09-05
Publication date: 1975-12-02
Anticipated expiration: 1992-12-02

Abstract

A zero initial insertion and full zero retraction force connector is provided including a housing and a folded leaf spring inserted into the housing. The leaf spring has various portions defining a pin, a socket, and a spring member. The spring 5 member extends from one side of the socket above the housing and is anchored in the housing at its free end. Depression of the spring member when two connectors mate causes one wall of the socket to move towards an opposing wall thereby to make stable electrical and mechanical contact with an inserted pin during the last portion of the insertion stroke in which the pin is inserted into the socket.

Description

United States Patent 1 Rosen 1 Dec.2, 1975 [75] Inventor: Harold Rosen, Nashua, NH.

[73] Assignee: Sanders Associates, Inc., Nashua,

[22] Filed: Sept. 5, 1974 [21] Appl. No.: 503,216

22,981 9/1969 Japan 339/75 MP Primary ExaminerJoseph H. McGlynn Attorney, Agent, or Firm-Louis Etlinger; Robert K. Tendler [57] ABSTRACT A zero initial insertion and full zero retraction force connector is provided including a housing and a folded leaf spring inserted into the housing. The leaf spring has various portions defining a pin, a socket, and a spring member. The spring 5 member extends from one side of the socket above the housing and is anchored in the housing at its free end. Depression of the spring member when two connectors mate causes one wall of the socket to move towards an opposing wall thereby to make stable electrical and mechanical contact with an inserted pin during the last portion of the insertion stroke in which the pin is inserted into the socket.

30 Claims, 7 Drawing Figures LAT RAL IIIIII" III IDISPLACEM ENT,44

Illilllll II/II) US. Patent Dec. 2, 1975 Sheet 1 of3 3,923,361

LATERAL DISPLACEMENT,44

FIGZ

US. Patent Dec. 2, 1975 Sheet 2 of3 3,923,361

mm F CONNECTOR COMPONEN US. Patent Dec. 2, 1975 Sheet 3 of3 3,923,361

FIG. 7

CONDUCTIVE STRIP, 106

O l 1, i J

PRINTED CIRCUIT ELECTIRHCAL CONNECTOR AND lCllRlClJl'll BOARD MOUNTING gYSTl'Jll/ll This invention relates to electrical connectors and more particularly to a zero initial insertion and full zero retraction force connector.

One of the most important problems associated with multi-pin electrical connectors is the problem of the force necessary to cause the mating of the male and female portions of the connector and the separation of these portions. it will be appreciated that if 2 ounces of force is required to insert each pin, for connectors having upwards of 200 pins the mating force is indeed considerable. Moreover, and perhaps more importantly, when the connections are pulled apart a large force is necessary to separate the two portions of the connector. The insertion and retraction problem associated with multi-pin connectors is particularly severe in the interconnection of printed circuit boards and cables having a large number of conductors. The subject invention solves this problem by providing that the force applied to a pin from one connector inserted into the socket of a mating connector be zero minimized during the mating and separation of the connectors.

The problem of the force necessary to connect and disconnect mating conductors centers around not only the convenience factor but also around the necessity for preventing the buckling of the pins. in high density packaging configurations it is desirable to make the connector pins thin. However, the pins oftentimes buckle when inserted. The subject invention solves the buckling problem by restricting the compressive or buckling forces on the pin to occur during only the last few mills of the insertion stroke, thereby effectively applying the buckling force to the extremely short uninserted pin section remaining. This totally eliminates pin buckling as a source of failure while additionally retaining the wipe action necessary for self-cleaning. Moreover, pin damage often occurs due to the jerk, or sudden relaxation of force upon separation. The subject connector described hereinafter also eliminates this potential for damage by quick release of the pin during separation.

By way of background, as described in connection with US. Pat. No. 3,474,387, prior art connectors generally utilize contacts which are in the form of deflectable simple beams in the female portion of the connector which are deflected into contact with the pins or posts from a mating male connector. The deflection of the simple beam is ordinarily accomplished by a cam eccentrically mounted relative to the center line of the connector and rotatable about an axis normal to the plane within which the beams are deflectable. As noted in the above mentioned patent, one of the major (lifticulties with the external cam actuated connector is that access to the cam is oftentimes approached from the lengthwise end of the connector instead of being accessable from the same direction in which the force is applied to cause mating of the male and female portions of the connector. in the case of printed circuit boards what this means is that when the circuit board is inserted it is necessary to actuate the cam from a direction which may be obscurred by either the walls of the cavity into which the circuit board is inserted or by other equipment or electronic components. Thus there is no easy access to the cam actuating member for either carnming the deflectable beams into contact with 2 the projecting pins or, for camming them away from the pins in the case of removal of the printed circuit board.

in the above mentioned patent, there is illustrated a two-part connector in which vertically mounted spring members are camrned into contact with a portion of the circuit board containing the contact pads. it will be appreciated that this connector is a two-part connector in which a carnming member contacts a spring member in order to urge it into contact with an adjacent male contact when the two portions of the connectors are squeezed together. What in effect has been provided therefore is a separate camming member. Moreover, the connector of this patent is not a hermaphroditic connector in the sense that in hermaphoditic connectors the same connector assembly is used as a male and female member.

Perhaps more importantly the thickness of the spring member in the above mentioned patent is such as to require a large amount of force in order to bring the spring member into contact with a contact pad on the inserted printed circuit board. The force necessary to make contact is dependent on the elasticity of the spring member which in turn is dependent at least in part on the thickness of the spring. It will be appreciated that the same spring member which is deflected to make contact with the inserted contact pad also extends outwardly of the connector to provide a contact pin or post. it is important for the structural stability of the pin that it be of sufficient thickness to withstand buckling. Since the deflected member and the pin are made from the same piece of metal, the resulting spring member in the connector housing is relatively stiff. This in turn results in the necessity of applying a relatively high force in order to deflect the spring member into contact with an inserted conductor. While this force may not be excessive in the case of one or two pins, the force is multiplied by the number of pins and therefore becomes a considerable problem when, for instance, 200 or more pins are provided.

The force necessary to deflect the spring member is also important when considering wear and reliability. This problem can perhaps be more readily appreciated by referring to US. Pat. No. 3,750.085. in this patent a spring is deflected into contact with an inserted conductor by the squeezing together of two parts of the connector. in this patent the spring member and pin are also from the same piece of metal. As before, the force necessary is directly related to the thickness of the spring member. When this force is excessive the point of contact between the end of the spring and the upper portion of the connector causes the spring to dig into the upper portion of the connector thus weakening it and/or scoring it by an amount directly proportional to the force necessary to establish the requisite contact force. In this connection, it will be appreciated that a thinner spring member would dig in less during the mating procedure and reliability would be improved.

The aforementioned problems are solved by the subject electrical connector which, because of its folded spring configuration, requires approximately onefourth the force normally used to establish the requisite contact force. The folded construction also provides a thick pin depending from the connector body which is integral to and is a part of the deflectable spring member. Because of the folding of the spring to form the pin, the pin is rigid and resists buckling while the spring portion, being only one-half the thickness of the pin is relatively easy to deflect and therefore requires less in the way of deflection force. The connector is also unitary in construction in the sense that it is not a two-part connector; it is hermaphroditic in the sense that the same connector is utilized both as a male and female member; and it is an initial zero insertion force and a full zero retraction force connector which permits easy insertion and extraction.

In one embodiment, the subject connector includes a housing having a horizontal channel in its upper face. A vertical channel extends through the body of the connector and communicates both with one end of the horizontal channel and with the bottom face of the connector housing. Within the horizontal and vertical channels is placed a folded leaf spring structure. The vertical channel has a wider upper portion and the folded leaf spring which projects down through the lower portion to form the pin of the connector is separated in this widened portion. One half of the leaf spring is stationary and rests against a sidewall of the widened portion. The other separated portion of the leaf spring ordinarily resides against an opposing vertical wall of the widened portion and is adapted to move into contact with an inserted pin when the bottom of a similarly constructed connector body impinges upon a portion of this leaf spring which projects above the top of the connector body through the upper channel. When the projecting portion of the spring is flattened, the laterally displaceable portion of the leaf spring within the vertical widened channel is pressed into contact with the downwardly depending pin from the connector immediately above.

During the first part of the insertion of a pin into the female socket portion of the connector the pin is free and no electrical or mechanical contact is made. During the last few mills of insertion the pin wipes against the socket as mechanical connection is made which results in a cleaning action. It will be appreciated that during the majority of the insertion stroke no force or load is applied to the pin, while during the last few mills of insertion, since force is necessary to make both the electrical and mechanical connection, the pin is loaded. Thus the term zero initial insertion force refers to a lack of force during the initial insertion of the pin. Since a load is only applied to the pin after the pin is almost fully inserted, pin buckling is minimized be cause the load is applied close to the base of the inserted pin where the lever arm is shortest and the mechanical stability is highest.

In this connector, there is no two-part body construction and there is no separate camming surface to urge the leaf spring into contact with an adjacent inserted conductor. Rather, the portion of the leaf spring projecting above the connector body, having been urged in a downward direction causes a translation of the laterally displaceable portion of the leaf spring into contact with the inserted conductor post. Final electrical and mechanical connection is maintained by the clamping together of the two adjacent connector housings. It will be appreciated therefore that the connector is of extremely simple construction in which a leaf spring is folded on itself along one portion and is separated from itself at another portion. Actuation takes place by flab tening a portion of the spring extending above its hous ing. The leaf spring is easily formed and is also easily inserted into the conductor body to form the aforementioned unitary hermaphroditic connector.

The resulting electrical connector has a projecting pin, which is double the thickness of the leaf spring. This, plus the fact that the load is applied to the pin close to its base only after almost complete insertion provides for anti-buckling protection. At the same time only one-half the thickness of the projecting pin or post is utilized in the leaf spring portion of the connector. This provides that only one-fourth of the force ordinarily necessary is exerted in achieving full contact pressure.

in operation, the laterally displaceable portion of the leaf spring resides against one wall of the vertical channel thereby to give clearance for the inserted pin from an adjacent connector without any frictional force being applied to this pin. As the pin is inserted further into the connector the bottom portion of the connector body from which the pin depends presses against the extending spring portion which projects upwardly above the top surface of the bottom. connector. When the pin is near fully inserted, the bottom of the upper connector depresses the upwardly extending spring portion thereby to laterally displace the leaf spring member into contact with the inserted pin to make the electrical connection. The mechanical connection is completed by clamping together the two connectors. Removal is quite simple since release of the two connectors results in a upward force being applied to the upper connector by the depressed leaf spring from the lower connector. This force initially aids in the separation of the connectors. After a predetermined separation the pin is completely free of frictional engagement with the lower connector leaf spring and is thereafter easily withdrawn. Thus, the compressed spring functions to aid in the removal of the upper connector unlike the two-part connectors of the prior art.

The particular hermaphroditic configuration also makes possible a new method of interconnecting printed circuit boards. in the usual configuration, printed circuit boards have end connectors which mate with rackmounted connectors when the board is inserted into place. This arrangement requires a separate rack mounted connector strip which increases the weight of the apparatus.

With the subject connector, printed circuit boards may be interconnected in a stacked arrangement without the use of separate rack mounted connectors. This results not only in weight reduction but also in a mechanically stable selfsupporting package.

It is therefore an object of this invention to provide a hermaphroditic zero initial insertion and full zero retraction force electrical connector of unitary construction;

It is another object of this invention to provide an electrical connector in which the insertion force necessary to provide sufficient contact engagement force is minimized.

It is yet another object of this invention to provide a low cost multipin connector comprised of only a housing and a spring having a folded configuration.

it is a further object of this invention to provide a connector system utilizing hermaphroditic components in which each component carries a folded leaf spring having a portion thereof extending above a surface of the component such that communication between the surface of one component and the extended spring portion upon mating of the connector components results in the displacement of a portion of the spring in a direction orthogonical to the applied force.

It is a further object of this invention to provide a zero initial insertion and full zero retraction force electrical connector in which no separate camming member is utilized.

It is a yet still further object of this invention to provide an improved method and apparatus for interconnecting printed circuit boards which reduces the weight of the connected configuration by eliminating the necessity for a card rack.

It is a yet still further object of this invention to provide a zero initial and full zero retraction force electrical connector which is more reliable and less prone to failure.

It is a yet still further object of this invention to provide a hermaphroditic zero initial insertion and full zero retraction force electrical connector having the pin and socket member being formed from the same leaf spring, with the pin portion having double the thickness of the socket portion thereby to prevent buckling of the pin while allowing increased flexability of portions of the socket which is actuated into frictional contact with a mating male member.

These and other objects of this invention will be better understood in connection with the following description in view of the appended drawings in which:

FIG. 1 is a cross sectional and partial perspective view of the subject connector illustrating a poriton of the connector component forming the male member inserted into a socket of the component forming the female member;

FIG. 2 is a partial cross sectional drawing illustrating a portion of the leaf spring of the connector which extends above the top surface thereof;

FIG. 3 is a perspective view of printed circuit boards stacked vertically and connected with the subject connector;

FIG. 4 is a partial sectional and perspective view of the circuit board and connector illustrated in FIG. 3;

FIG. 5 is a partial exploded view illustrating the method of replacement of circuit boards and connectors with the configuration illustrated in FIG. 3;

FIG. 6 is a partial perspective and exploded diagram illustrating the use of the subject connector in a conventional end-connector configuration for circuit board applications; and

FIG. 7 is a partial perspective and sectional view illustrating the subject connectors connected to a circuit board in an end-connector configuration without the use of additional connecting leads.

Referring now to FIG. 1 a hermaphroditic connector 10 is illustrated as having a folded leaf spring member 12 inserted into a vertically extending cavity 14 in connector housing 11. Cavity 14 has a narrow portion 16 and a widened portion generally indicated at 18. The spring member 12 extends upwardly and outwardly of cavity 14 and includes separated

spring portions

19 and 20 which ordinarily rest against the walls making up the widened portion 18 of cavity 14. A horizontal portion 21 of spring member 12 projects outwardly of the connector housing 11.

A second horizontally extending portion 22 of leaf spring member 12 extends to the right in a horizontal channel 24 cut in the top surface 26 of housing 11. Spring portion 22 includes a bent portion 28 which extends above face 26 of the connector 10. Additionally, an additional bent portion 30 is provided between

spring portions

19 and 28.

6 Horizontal forces (F generated by spring portion 28 of spring member 12 is closely approximated by the simple equation set out hereinafter,

E= Youngs Modulus '-w here The vertical force (F,,) is approximated by the following equation:

8 E I Where F K K (9, change in curvature of radiused portion) H s therefore expressed by:

. Kl K v A similarly configured connector 36 is located immediately above connector 10 and has a downwardly depending folded spring portion forming a pin or post 38 such that connector 36 functions as the male connector.

As can be seen from FIG. 1 the portion of the spring projecting through cavity portion 16 is of a double thickness, 2w, as compared to the thickness of the separated

spring portions

19 and 20, e.g. w. As mentioned hereinbefore, the 2w width provides mechanical stability for the pin while the 37 1w width of spring portion 19 provides for increased flexability of this member, thereby to reduce the force, F necessary in deflecting this member into contact with an inserted pin or post.

It will be appreciated that spring portion 21 extending outwardly of the housing, may be provided with any suitable means of making electric contact thereto such as the threaded screw 40, or a conductive strip (not shown) continuing along the outside of the conductor housing to intersect a printed circuit board. Additionally it will be appreciated that either spring portion 21 or spring portion 22 may be made to extend outwardly of the housing for convenient connection as desired. In an embodiment to be described in connection with FIG. 4, there need be no projecting portion, as the connection to the various spring members is made at the respective pins.

In operation, connector 36 is moved downwardly with respect to connector 10 such that pin 38 is inserted between the

separated spring portions

19 and 20. It will be appreciated that there is provided enough clearance between these spring portions to permit the insertion of the pin without frictional contact. At a certain point in the insertion of pin 38 a bottom surface 42 of the connector 36 impinges upon the top surface of spring portion 28 deflecting it downwardly with a force F The downward deflection of this spring portion results in the lateral displacement of spring portion 19 which contacts pin 38 with a force F derived from the previous equations.

It will be appreciated that

connectors

10 and 36 may be clamped together in any convenient manner thereby to form a stable electrical and mechanical contact between spring member 12 and pin 38. Removal or separation of the two connectors is accomplished by removing the aforementioned clamping means such that spring portion 19 returns to its initial rest condition along side the wall of the widened portion 18.

Because of the folded configuration of the spring member 12 approximately one-fourth of the force, F is necessary to create a predetermined contact force as compared to connectors in which the bendable beam is made of the same thickness as the pin extending therefrom.

Referring now to FIG. 2 a cross-section of a portion of connector is illustrated showing that the angle 6 subtended by the ends of the

curved portion

48 and 50 may be varied as desired. It has been found, however, that angle 0 in a preferred embodiment is preferably 90 to maximize lateral deflection.

Referring now to FIG. 3, with connectors of the type described, printed circuit boards 56 may be arranged in a stacked configuration and interconnected by the subject connectors. The connectors illustrated by the reference characters 60 are located in a unitary elongated connector body as shown. The sandwich structure illustrated is accomplished by throughbolting the sandwiched structure with the bolts 62.

Interconnection is accomplished, as illustrated in FIG. 4, by the placement of a printed circuit board 64 between two connectors, illustrated in this figure by

reference characters

66 and 68. On the bottom of printed circuit board 64 is a conductive strip 70 which is in electrical contact with contact pin 72 from connector 66. The connection is most easily made by creating a hole in both the printed circuit board and its conductor and inserting the pin from connector 66 through this hole. If the hole is throughplated, no further connecting means may be necessary. Alternatively the pin may be soldered, braised or otherwise electrically connected to the conductor on the printed circuit board after insertion of the pin through the hole. This connection method establishes an electrical connection between conductor 70 and a spring member 74 carried by connector 68 by virtue of the insertion of pin 72 into connector 68. These interconnections can obviously be selectively made such that selected conductors of one printed circuit board may be connected to selected conductors of the circuit board either above or below it.

Referring to FIG. 5, it will be appreciated that defective circuit boards may be replaced by another circuit board-connector combination illustrated by the combination of circuit board 64 with connector 66. This provides a convenient stacking and replacement system for circuit boards which eliminates the necessity of a separate rack mounted connector strip.

The subject connector can also be used in a conventional printed circuit board connector system as illustrated in FIG. 6, in which a printed circuit board 80 may be provided with the subject connector illustrated by the reference character 82, in which the connector is mounted at one end of the circuit board. Alternatively, any suitably configured male pin connector strip may be mounted on and connected to the printed circuit board, it being understood that use of the subject connector is convenient since only one lot of connectors need be ordered for both the printed circuit board connector and the rack mounted connector. In this mounting system, the subject connector is also adapted as a rack mounted connector strip 84 which is bolted to the rack into which the printed circuit board is to be inserted.

Connector 82 may have its individual conductors connected to printed circuit board in the manner illustrated, e.g. by connecting wires 86 from spring extensions 88 to contact pads 90 on the circuit board. Alternatively, as illustrated in FIG. 7, any projecting portion of a leaf spring may be inserted into an appropriate hole in the circuit board to eliminate the necessity of separate wires. For example, in FIG. 7 pin projects through through-plated hole 102 in printed circuit board 104 and is connected to a conductive strip 106 to mount the connector on the circuit board as well as connect it thereto.

Referring back to FIG. 6, the circuit board may be secured to the rack mounted connector by bolts such as the bolt illustrated at 92. It will be appreciated that unlike the aforementioned cam-actuated release mechanisms the head of the bolt is accessable along the same direction as the direction of insertion of the printed circuit board thereby to facilitate connector mating.

What has been provided, therefore, is a unitary, initial zero insertion force and full zero retraction force, hermaphroditic connector having a folded spring configuration for providing both the male and female members of the connector. In one embodiment the folded spring is 24 X 24 mills which is precisely the standard pin dimensions for printed circuit board connectors. Because the female portion of the connector is only one-half as thick as the male portion, the force necessary to make adequate frictional contact is minimized. Moreover, for added strength the folded portion of the spring member in its housing provides for considerable structural stability of the pin. It is obvious that the spring member can be made of any suitable spring material such as beryllium copper, spring brass, etc. and may take on any convenient housing configuration to accomodate cables as well as printed circuit boards.

Although a specific embodiment to the invention has been described in considerable detail for illustrative purposes, many modifications will occur to those skilled in the art. It is therefore desired that the protection afforded by Letters Patent be limited only by the true scope of the appended claims.

I claim:

1. An electrical connector comprising: a housing and an electrically conductive spring member, said spring member folded on itself to provide a pin and separated from itself to form a socket, one portion of the spring member forming a laterally deflectible wall of said socket and including an extension having a bent portion, said spring member being mounted in said housing with said pin extending from one surface of said housing, said bent portion extending above a second surface of said housing and means for deflecting said one portion upon towards an opposite wall of said socket upon depression of said bent portion.

2. The connector of claim 1 wherein said folded portion includes two spring portions fixedly attached one to the other.

3. The connector of claim 1 wherein said housing is made from a solid block of material having a vertical channel with narrow and widened portions communicating with opposing surfaces of said block, and a horizontal channel 4. The conductor of claim 1 wherein said extension extends substantially at right angles to said one spring portion.

5. The connector of claim 4 wherein said extension includes a further radiused portion between said bent portion and said one spring portion.

6. The connectorof claim 4 wherein said bent portion is radiused.

7. The connector of claim 6 wherein the angle subtended by said radiused bent portion is 90.

8. An electrical connector comprising a housing, a spring member folded on itself to provide a pin and separated from itself above the folded portion to form a socket, one portion of the spring member forming a wall of said socket, being deflectable towards an opposite wall, said spring portion including an extension having a bent portion, said spring member being mounted in said housing with said pin extending from a face of said housing and said bent portion extending above another face of said housing, the free end of said bent portion being fixedly attached to said housing, and means for deflecting said one portion responsive to depression of said bent portion.

9.. The connector of claim 8 wherein the folded portion of said spring member includes two spring portions fixedly attached one to the other.

lb. The connector of claim 8 wherein said housing is made from a solid block of material having a vertical channel with narrow and widened portions communicating with opposing surfaces of said block, and a horizontal channel communicating with the widened portion of said vertical channel and one of said opposing surfaces, said spring member being inserted into said channels.

ll. The connector of claim 8 wherein said extension extends substantially at right angles to said one spring portion.

12.. The connector of claim ll wherein said extension includes a further radiused portion between said bent portion and said one spring portion.

113. The connector of claim 11 wherein said bent portion is radiused.

14. The connector of claim l3 wherein the angle subtended by said radiused bent portion is 90.

15.. A hermaphroditic zero initial insertion and zero retraction force connector comprising:

a housing; and,

an electrically conductive spring member having a portion folded on itself, two additional portions of said spring member being spaced apart to form a socket above said folded portion, said spring member mounted in said housing with a portion of said folded portion extending exteriorally of said housing from one surface thereof, one of said two additional portions forming a deflectible beam, said det'lectible beam including a further spring portion extending from said deflectible beam at substan tially right angles thereto, said further portion including bent portion means extending above another surface of said housing for deflecting said deflectible beam upon depression of said bent portion means, said further portion being fixedly attached to said housing at a point to the side of said bent portion away from said deflectible beam.

116. The connector of claim l wherein said folded portion includes two spring portions fixedly attached one to the other.

117. The connector of claim 15 wherein said housing is made from a solid block of material having a vertical channel with narrow and widened portions communicating with opposing surfaces of said block, and a horilb zontal channel communicating with the widened portion of said vertical channel, said spring member being inserted into said channels.

18. The connector of claim 15 wherein said bent portion is radiused.

19. The connector of claim 18 wherein the angle subtended by said radiused bent portion is 20. The connector of claim 19 wherein said extension includes a further radiused portion between said bent portion and said one spring portion.

2t. A method of mounting printing circuit boards comprising sandwiching said boards between electrical connec tors having pins extending from one surface and sockets exposed at an opposing surface, said sockets adapted to receive pins projecting through an intermediate printed circuit board from a connector immediately thereabove, said connectors comprising a housing and a spring member folded on itself to provide a pin and separated from itself above the folded portion to form a socket, one portion of the spring member forming a wall of said socket being deflectible towards an opposite wall, said one portion including an extension having a bent portion, said spring member being mounted in said housing with said pin extending from a face of said housing and said bent portion extending above another face of said housing, the free end of said bent portion being fixedly attached to said housing, and means for deflecting said one portion responsive to depression of said bent portion, and depressing the bent portions of the connector by clamping the sandwiched boards and connectors together to secure mating pins and sockets.

22. A method of releaseably interconnecting printed circuit boards comprising providing each printed circuit board with a hermaphoditic electrical connector at opposite ends of said printed circuit board, each of said connectors having a pin extending from one surface and a socket exposed at an opposite surface, each of said pins being electrically connected to selected conductors on the printed circuit board on which the connector is mounted; and

stacking said circuit boards carrying said connectors one on top of the other such that pins extending through a circuit board are inserted into corresponding sockets of a connector mounted on a next adjacent circuit board whereby a vertical sandwich structure of interconnected boards is formed, said hermaphoditic electrical connector comprising a housing and a spring member folded on itself to provide a pin and separated from itself above the folded portion to form a socket, one portion of the spring member forming a wall of said socket being deflectable towards an opposite wall, said one portion including an extension having a bent portion, said spring member being mounted in said housing with said pin extending from a face of said housing and said bent portion extending above another face of said housing, the free end of said bent portion being fixedly attached to said housing, and means for deflecting said one portion responsive to depression of said bent portion, and depressing the bent portions of the connectors by clamping the stacked boards and connectors together to secure mating pins and sockets.

23 in combination a printed circuit board having conductive layers thereon, and

an electrical connector mounted at one end thereof,

said connector comprising a housing and an electrically conductive spring member, said spring member folded on itself to provide a pin and separated from itself above the folded portion to form a socket, said spring member being mounted in said housing such that said pin extends from one surface of said housing and such that said socket communicates with an opposing surface of said housing, one portion of the spring member forming a wall of said socket being deflectable towards an opposite wall, said one portion including an extension having a bent portion, the free end of said bent portion being fixedly attached to said housing, and means for deflecting said one portion responsive to depression of said bent portion.

24. The combination of claim 23 wherein said connector is mounted with said pin extending in a direction parallel to the plane of said circuit board.

25. The combination of claim 23 wherein said connector is mounted with said pin extending through said circuit board.

26. The combination of claim 25 wherein said pin is connected to one of said conductive layers at the point at which said pin extends through said circuit board.

27. The combination of claim 25 and including means for connecting said pin to a selected conductive layer on said circuit board and further including a number of board-connector combinations stacked one on top of the other with a pin from one circuit board extending into a socket of a connector on a circuit board immediately thereunder.

28. The combination of claim 27 wherein one of the spring members forming a wall of said socket includes an extension having a bent portion, said spring member 12 being mounted such that said bent portion extends above said opposing surface and is adapted to coact with the bottom of a circuit board immediately thereabove to deflect said one spring member into contact with the pin from the circuit board immediately thereabove.

29. The combination of claim 28 wherein a number of pins extend from each circuit board, whereby release of one circuit board-connector combination from an adjacent circuit board-connector combination is easily effected.

30. In combination a hermaphroditic electrical connector of the type comprising: a housing and an electrically conductive spring member, said spring member folded on itself to provide a pin and separated from itself to form a socket, one portion of the spring member forming a deflectible wall of said socket and including and extension having a bent portion, said spring member being mounted in said housing such that said pin extends from one surface of said housing, and such that said bent portion extends above a second surface of said housing, said bent portion including means for deflecting said deflectible wall towards an opposite wall of said socket upon depression of said bent portion;

a body having a connector post depending therefrom and adapted to be inserted into the socket of said connector, said body having a surface adapted to coact with the bent portion of said connector to depress it when the housing of said connector and said body are forced together; and

means for maintaining said housing and body forced together thereby to deflect said one spring portion into contact with said post.

UNITED STATES PATENT OFFICE CETEFICATE 0F CORRECTION 0 PATENT NO. 3, 923, 36;

DATED February 18, 1976 INVENTOR(S) Harold Rosen It is certified that error appears in the above-identified patent and that said Letters Patent 9 are hereby corrected as shown below:

Column 8, line 56 delete "upon", first occurrence. O

Signed and gcaled this twenty-seventh Day Of April 1976 Q [SEAL] Arrest.

RUTH c. MASON c MARSHALL DANN Augsrmg ("mlmiflimlvr flumnts and Trademarks

Claims

3. The connector of claim 1 wherein said housing is made from a solid block of material having a vertical channel with narrow and widened portions communicating with opposing surfaces of said block, and a horizontal channel

4. The conductor of claim 1 wherein said extension extends substantially at right angles to said one spring portion.

6. The connector of claim 4 wherein said bent portion is radiused.

7. The connector of claim 6 wherein the angle subtended by said radiused bent portion is 90*.

9. The connector of claim 8 wherein the folded portion of said spring member includes two spring portions fixedly attached one to the other.

10. The connector of claim 8 wherein said housing is made from a solid block of material having a vertical channel with narrow and widened portions communicating with opposing surfaces of said block, and a horizontal channel communicating with the widened portion of said vertical channel and one of said opposing surfaces, said spring member being inserted into said channels.

11. The connector of claim 8 wherein said extension extends substantially at right angles to said one spring portion.

12. The connector of claim 11 wherein said extension includes a further radiused portion between said bent portion and said one spring portion.

13. The connector of claim 11 wherein said bent portion is radiused.

14. The connector of claim 13 wherein the angle subtended by said radiused bent portion is 90*.

15. A hermaphroditic zero initial insertion and zero retraction force connector comprising: a housing; and, an electrically conductive spring member having a portion folded on itself, two additional portions of said spring member being spaced apart to form a socket above said folded portion, said spring member mounted in said housing with a portion of said folded portion extending exteriorally of said housing from one surface thereof, one of said two additional portions forming a deflectible beam, said deflectible beam including a further spring portion extending from said deflectible beam at substantially right angles thereto, said further portion including bent portion means extending above another surface of said housing for deflecting said deflectible beam upon depression of said bent portion means, said further portion being fixedly attached to said housing at a point to the side of said bent portion away from said deflectible beam.

16. The connector of claim 15 wherein said folded portion includes two spring portions fixedly attached one to the other.

17. The connector of claim 15 wherein said housing is made from a solid block of material having a vertical channel with narrow and widened portions communicating with opposing surfaces of said block, and a horizontal channel communicating with the widened portion of said vertical channel, said spring member being inserted into said channels.

18. The connector of claim 15 wherein said bent portion is radiused.

19. The connector of claim 18 wherein the angle subtended by said radiused bent portion is 90*.

20. The connector of claim 19 wherein said extension includes a further radiused portion between said bent portion and said one spring portion.

21. A method of mounting printing circuit boards comprising sandwiching said boards between electrical connectors having pins extending from one surface and sockets exposed at an opposing surface, said sockets adapted to receive pins projecting through an intermediate printed circuit board from a connector immediately thereabove, said connectors comprising a housing and a spring member folded on itself to provide a pin and separated from itself above the folded portion to form a socket, one portion of the spring member forming a wall of said socket being deflectible towards an opposite wall, said one portion including an extension having a bent portion, said spring member being mounted in said housing with said pin extending from a face of said housing and said bent portion extending above another face of said housing, the free end of said bent portion being fixedly attached to said housing, and means for deflecting said one portion responsive to depression of said bent portion, and depressing the bent portions of the connector by clamping the sandwiched boards and connectors together to secure mating pins and sockets.

22. A method of releaseably interconnecting printed circuit boards comprising providing each printed circuit board with a hermaphoditic electrical connector at opposite ends of said printed circuit board, each of said connectors having a pin extending from one surface and a socket exposed at an opposite surface, each of said pins being electrically connected to selected conductors on the printed circuit board on which the connector is mounted; and stacking said circuit boards carrying said connectors one on top of the other such that pins extending through a circuit board are inserted into corresponding sockets of a connector mounted on a next adjacent circuit board whereby a vertical sandwich structure of interconnected boards is formed, said hermaphoditic electrical connector comprising a housing and a spring member folded on itself to provide a pin and separated from itself above the folded portion to form a socket, one portion of the spring member forming a wall of said socket being deflectable towards an opposite wall, said one portion including an extension having a bent portion, said spring member being mounted in said housing with said pin extending from a face of said housing and said bent portion extending above another face of said housing, the free end of said bent portion being fixedly attached to said housing, and means for deflecting said one portion responsive to depression of said bent portion, and depressing the bent portions of the connectors by clamping the stacked boards and connectors together to secure mating pins and sockets.

23. In combination a printed circuit board having conductive layers thereon, and an electrical connector mounted at one end thereof, said connector comprising a housing and an electrically conductive spring member, said spring member folded on itself to provide a pin and separated from itself above the folded portion to form a socket, said spring member being mounted in said housing such that said pin extends from one surface of said housing and such that said socket communicates with an opposing surface of said housing, one portion of the spring member forming a wall of said socket being deflectable towards an opposite wall, said one portion including an extEnsion having a bent portion, the free end of said bent portion being fixedly attached to said housing, and means for deflecting said one portion responsive to depression of said bent portion.

28. The combination of claim 27 wherein one of the spring members forming a wall of said socket includes an extension having a bent portion, said spring member being mounted such that said bent portion extends above said opposing surface and is adapted to coact with the bottom of a circuit board immediately thereabove to deflect said one spring member into contact with the pin from the circuit board immediately thereabove.

30. In combination a hermaphroditic electrical connector of the type comprising: a housing and an electrically conductive spring member, said spring member folded on itself to provide a pin and separated from itself to form a socket, one portion of the spring member forming a deflectible wall of said socket and including and extension having a bent portion, said spring member being mounted in said housing such that said pin extends from one surface of said housing, and such that said bent portion extends above a second surface of said housing, said bent portion including means for deflecting said deflectible wall towards an opposite wall of said socket upon depression of said bent portion; a body having a connector post depending therefrom and adapted to be inserted into the socket of said connector, said body having a surface adapted to coact with the bent portion of said connector to depress it when the housing of said connector and said body are forced together; and means for maintaining said housing and body forced together thereby to deflect said one spring portion into contact with said post.