CA1054236A

CA1054236A - Connector assembly housing and retaining member for a printed circuit board

Info

Publication number: CA1054236A
Application number: CA229,692A
Authority: CA
Inventors: Kazuyasu Sugimoto; Hiroshi Yamaya; Kameki Ishimoto
Original assignee: Matsushita Electric Industrial Co Ltd
Current assignee: Panasonic Holdings Corp
Priority date: 1974-06-20
Filing date: 1975-06-19
Publication date: 1979-05-08
Also published as: DE2527318C3; DE2527318A1; GB1508507A; FR2275965A1; IT1040664B; FR2275965B1; DE2527318B2

Abstract

Abstract of the Disclosure A connector assembly for a printed circuit board having electrical contacts on at least one surface of its edge portion, comprising a housing structure having spaced parallel wide wall portions at least one of which has electrical contact elements carried on the inner face thereof, and at least one elastic retaining member partly positioned within the housing structure and in engagement with at least one of the side wall portions of the housing structure for being in pressing engagement with the printed circuit board and thereby holding the circuit board in a predetermined fixed position having the contacts in close contact with the contact elements on the housing structure.

Description

~(~5423f~

The pre~e~-t invention relates to a connector assembly fo,r a printed circuit board having electrical contactq printed or otherwise forn~ed on at leas-t one surface of its edge portion.
A conventional connector for a printed circuit board comprises a housing structure having a pair of side walls which carry elastic contact elements arranged to be re~pectiYely in contact with the contacts on the ed~e portion of the printed circuit board fitted to the housing structure. The printed circuit board is held in position relative to the ho,using structure by the ' elastici'ty of the contact elements carried on the hou~ing structure. In the event the housing structure or the printed circuit board is subjected to mechanical l,~ shocks or an impact during use, the printed circuit ; board may be dislodged from the housing structure or may be dislocated from its initial po~ition relative to the housing structure. This will cause interruption of the electrical connection between thq contacts on ~o the printed circuit board ~nd the contact ele~ents on the housing structure. If, furthermore, the printed circuit board i~ forced against the contact element~ on the housins struGture wlth an exces~ of pressure which may be caused by an impact exerted on the printed clrcuit ~,5 board or the hou~ing ~tructure, then the contact

- 2 -! ;, 1~5~6 resi~tance at the ~urface of contact between each ot`
the contact~ on the circuit board and each of the cont~ct element~ on the housin$ ~tructure will be l unusually increased and provide a cause of shortened ¦ 5 life of the printed circuit board and the connector assembly.
i The housing structure is usually fastened to a mother board by mean~ of screw~ which are driven through screw holes formed in extensions of the housing structure. Time consuming steps are therefore required i~ mounting the hou~ing atructure on the mother board during production of the connector assembly. ~o dis-penae with 8uch elaborate step~ the contact elements which project outwardLy from the bottcm wall of the 1 15 housing structure may be soldered or otherwi~e fixedly secured to the bottom wall as in some of the connector ~, assemblies presently in use. In the prior art connector as~embly of this nature, however, it is difficult to have the contact elements on the housing structure ''>0 fixedly and assuredly connected to the mother board.
If, furthermore, the printed circuit board or the-connector assembly is subjected to mechanical ~hocks or impact during use, the contact element~ on the housin$ structure tend to be moved on the contact-'~5 carrying edge portion of the printed circuit board

- 3 ~

.

, ~oS4Z36 and is also causative of an increase in the contact resistance between the contacts on the printed circuit board and the con-tact elements on the housing structure.
The present invention contemplates elimination of all these drawbacks that have been inherent in the prior art connec-tor assemblies for printed circuit boards.
In accordance with the present invention, there is provided a connector assembly which comprises a housing struc-ture having a pair of spaced parallel side wall portions forming therebetween an elongated groove open at its top end and a bottom wall portion located at the bottom of the elongated groove, at least one of the side wall portions having a plura-lity of electrical contacts carried on the inner face thereof, and at least one elastic retaining member for retaining, in use, the printed circuit board to the housing structure, the retain-ing member being formed separately of and detachably mounted on the housing structure and being at least in part positioned in the elongated groove and in engagement with at least one of the side wall portions of the housing structure for being, in use, in pressing engagement with at least one surface of the contact-carrying edge portion of a printed circuit board and thereby holding the printed circuit board in a predetermined fixed position having its edge contacts respectively in contact with the contact elements on the housing structure.
The features and advantages of the connector assembly according to the present invention will become 105~23~

more apparent f`rom the f~llowing de#cription tak~ll in conjunction with the accoDIpanyin$ ~r~wing~ in whicl~
lik~ r~t`erenc~ l~umeral~ de~i~nate corres~on~in~ ~o~tion~, members and ~tructures and in which:
: 5 Fig~ 1 lS a perspective view which shows a repre-sentative example of a prior art connector assembly for a printed circuit board;
Fig. 2 is a fragmentary perspective view ~howing j a preferred embodiment of A connector assembly according .10 to the pre~ent invention;
Fig. 3 is a perspective view which ~howq an un-, stres~ed condition of a retaining member forming part 7 of the embodiment illuRtrated in Fi~. 2;
Fig. 4 is a fragmentary perspective view showing l.5 a modification o~ the embodiment illustrated in Fig, 2;
F`ig. 5 iR a perspective view which shows an unstressed condition of a retaining member forming part of the embodiment illu~trated in Fig, 4;
Fig. 6 is a fragmentary perspective view Rhowing .,0 another modification of the embodiment illustrated in ~! ~ig- 2;
Fig. 7 is a fragmentary perspect~ive view showing still another mod.ification of the smbodiment illustrated in F`ig. 2;
~5 Figs, 8 and 9 are perspective views each .~howing .

~,oS4Z36 a modification of the retaining ~emb~r lllustrated in Fi~. 3;
Fig. 10 i~ a perspective view showing a modifi-cation of the retaining member illustrated in Fig. 5;
Fig. 11 is a sectional vlew showing an arrangement in whieh the retaining member shown in Fig. 10 is ; fitted to the hQusing structure of the connector ~ssembly, the section of the retaining member being taken on line XI-XI of Fig. 10;
Fig. 12 is a fragmentary sectional view showing a modification of each of the retaining members shown in Figs~ 2 to 11;
~, Fig. 13 i~ a fragmentary perspective view showing till another preferred embodiment of the connector ~L5 a~sembly according to the pre~ent invention;
Fig. 14 is a perYpective view showing an unstres3ed condition of a retaining member incorporated in the embodiment illustrated in Fig. 13;
Fig. 15 ig a fragmentary perspective vi'ew Yhowing ~0 a modification of the embodiment illustrate~d in Fi~. 14;
Fig. 16 is a fragmentary perspective view which . . .
shows still another preferred embodiment of the connector assembly according to ~he present invention;
Fig. 17 is a perspective view showing an unstressed condition of a retaining member forming part of the , ~oS4236 .,;., embodiment illustrated in Fig. 16; -Fig. 18 is a perspective view showing still another preferred embodiment of the connector a~sembly according to the present invention;
Fig. 18a is a fragmentary perspactive view showing, to an enlarged scale, part of a modification of the embodiment illustrated in Fig. 18; and Fig. 19 is a fragmentary perspective view showing 7 still another preferred embodiment of the connector ' 10 assembly according to the present invention.
Reference will now be made to the drawings, ~irst to Fig. 1 which illustrates a representative example of the prior art connector assembly for a printed circuît 7 board a portion of which is indicated by reference 7 L5 numeral 20. The printed circuit board 20 has a plurality i of conductive contacts 22 which are arranged in an array on each or one of the surfaceq of an edge portion of the board 20 and which are spaced apart, usually equidis-tantly, from each other as shown. The contacts 22 are, ~o in this instance, assumed to be provided on both surfaces of the printed circuit board 20, although those o~ only ; one of the surfaces are seen in Fig. 1. The connector assembly i9 used for providing electrical connections i from these contacts 22 of the printed circuit board 20 ~ ~5 to leads of various external circuit components (not .. .

, 1054Z36'"
shown) of an electric equipment or instrumentation and is largely composed of a unitary housing structure 24 and a mother board 26 both of which are formed of electrically insulating material. The housing structure 5 24 is made up of a pair of spaced parallel side wall portions 28 and 28 ~ forming an elongated groove 30 therebetween, a pair of end wall portions 32 and 32 7 located at the lo~gitudinal ends of the elongated groove 30, a bottom wall portion 36 located at the bottom of the elongated groove 30 ~ and a pair of longitudinal exten~ions 38 and 38~ which project longi-tudinally outwardly from the lower ends of the end ! wall portions 32 and 321 ~ respectively, the longLtudinal extensions 38 and 381 being formed with screw holes 40 and 40~ ~ respectively. On the other hand, the mother board 26 is formed with screw holes 42 and 421 which ' are located in correspondence with the screw holes 40 r, and 401 in the logitudinal extensions 38 and 381 ~
respectively, of the hou~ing structure 24. The housing ~ 20 structure 24 is thus fixedly mounted on one face of the ¦ mother board ~6 by means of screws 44 and 44 ~ which are , driven through tbe screw holes 40 and 401 and the screw ; holes 42 and 42~, respectively.
,~ The side wall portions 28 and 281 of the housing '~,25 structure 24 thus constructed are formed with vertical _ 8 --., ~05423~

grooves or r~cesses 46 and 46', respectively, which extend between the upper and lower ends of the respec-tive inner faces of the side wall portions 28 and 28'.
The vertical grooves or rece~ses 46 and 46' are located respectively in alignment with the contacts ~Y~on the , opposite -sur~aces of the printed circuit board 20 and are open at the lower end of the bottom wall portion 36 , respectively through apertures (not shown) which are formed in the bottom wall portion 36. The mother board 26 is ~ormed with apertures 48 and 48' which are j arranged in array~ corresponding to the apertures thus formed in the bottom wall portion 36 of the housing structure 24. The apertures 48 in the mother board 26 ! are respectively in alignment with the vertical grooves ;l5 or recesses 46 in one side wall portian 28 of the 1 housin~ structure 24 and likewise the apertures 48' in ¦ the mother board 26 are respectively in alignment with the vertical grooves or recesses 46' in the other side ( w811 portion 28' of the housing structure 24. In the vertical grooves or rece~ses 46 and 46' are fixedly received limbs or elastic elongated contact elemerrts 50 and 50~, respectively. The contact-elements 50 and . .
50' are passed through the apertures in the bottom wall portion 36 of the housing structure 24 and through the ~"5 apertures 48 and 48', respectively, in the mother board _ 9 _ 1~Y~3~?

Z6 and projoct outwardly or downwardly frolll th~
underside o,f the mother board 26 for being connected to the lead~ of external circuit components (not ~llown).
~, The printed circuit board 20 is press fitted into the elongated ~roove 30 in the housing structure 24 and is thus snugly gripped between the inner faces of the side wall portions 28 and 28~ of the housin$
~tructure 24. The contacts 22 of the printed circuit t board 20 are thus respectively held in contact with the flexible contact elements 50 and 50' received in the ~ertical grooves or reces~es 46 and 46' in the side wall portions 28 and 28' of the housing ~tructure 24, providing electrical connection between each of t~le contacts 22 of the printed circuit board 20 and each f the contact elements 50 and 50' on the side wall portions 28 and 28~ of the housing structure 24.
~ The printed circuit board 20 is retained to the i hou~in$ structure 24 by reason of the elasticity of the t~ contact elements 50 and 50' on the side wall portions 28 and 28' of the housin$ structure 24. In case, therefore, the connector assembly or the printed ~ir-; cuit board 22 is subjected to mechanicaI shockq or an impact durin$ use, the printed circuit board 20 may be ! dislodged from the housing structure 24 or dislocated 1 25 from its initial positlon relative to the hou~ing 105~236 structure ~4, interruptinS the electrical connections between the, con-tacts ~of the circuit board 20 and the contact elements 50 on the housing structure 24.
If, furthermore, the printed circuit board 20 is forced against the contact elements 50 or 50~ by an increased pressure which may be c~ùsed by an impact exerted on the printed board 20 or the housing structure 24~ there will result an increase in the contsct resistance at the surface of contact between each of the contacts ! lo 22 of the printed circuit board 20 and each of the , contact elements 50 and 50' on the housing ~tructure 24. This will give rise to shortening of the life of the contact elements 50 and 50~ and accordingly of the ~ service life of the connector assembly as a whole, as i 15 previously noted.
As also pointed out previously, a time-consuming process is required in mounting the housing structure 24 on the mother board 26 during production of the connector assembly. To eliminate such a process, the ~o contact elements 50 snd 50' projecting outwardly from the bottom wall portion 36 of the housing structu~e 24 may be soldered or otherwise fixedly secured to the bottom wall portion 36 as in some of the prior art connector assemblies having basic configurations similar to that shown in l~ig. 1. In the prior art connector .

~054Z36 `.

assembly of this type, however, it is difficult to have the contact elements 50 and 50' firmly fixed to the mother board 26 and precisely positioned relative to the respectively associated contacts 22 of the printed circuit board 20. If, thus, the printed cir-cuit board 20 or the connector assembly i~ su~jected to mechanical shocks or impact during use, the contact elements 50 and 50' on the hou#ing structure 24 tend to be moved on the respectively associated contacts 22 of the circuit board 20 and, a~ a consequence, cause an increase in the contact resistance between each of j the contacts 22 of the printed circuit board 20 and the ' aasociated one of the contact element~ 50 and 50' on j the housing structure 24. The goal of the present invention i Q to provide a useful sollution to the above-mentioned problems which have thus far been inherent in the prior art connector a~semblies for printed circuit board~.
t Referrins to F`ig. 2, an embodiment of the present ~20 invention comprises a housing structure 52~and a mother 'i board 54. The housing structure 52 and the mother board 54 are configured e~sentially,si~ilarly to their i, respective counterparts 24 and 26 ~n the prior art '- connector assembly shown in Fig. 1 except that the ,25 housin$ structur~ 52 i~ void o~ the longitudinal 105~236 `

extensions 38 and 38' forming part of the housing structure 24 and acoordingly that the mother board 54 is void of the ~crew holes 42 and 42' formed in the mother board 26. A~ will be underqtood a~ the description proceeds, the housing structure 52 i~ thus i~ affixed to the mother board 54 without aid of the cl, B screws /lt~ aAd 4ll! which are used in ~ prior urt connector assembly illustrated in 1~`1g. 1.
Similarly to the housing structure 24 of the assembly shown in FiS. 1, the housing structure 52 of the embodiment illustrated in Flg. 2 has a pair of , spaced parallel side wall portion~ 56 and 56' forming j~ ~n elon$ated groove 58 therebetween and a bottom wall portion 60 located at the bottom of the elongated ,,15 groove 58. The bottom wall portion 60 is integral ; with a base portion 62 extending from the lower face of the bottom wall portlon 60 as illustrated. Each of the side wall portions 56 and 56' is formed with a number of vertical grooves or rece~;ses 64 extending '20 between the upper and lower ends of the inner face of s the side wall portion and opening at the lower end of the bottom wall portion 60 respectively through aper-tures (not shown) which are formed in the bottom wall j portion 60. 'rhe vertical grooves or recesses 64 are ~5 located in alignment with the contacts (not shown in ( ~os4Z3~

Fig, 2) of the printed circuit board 20 to be fitted to the connector assembly, as in the case of the prior art connector assembly shown in Fig. 1. The mother board 54 is formed with apertures (not shown) which are located in alignment with the apertures thus formed in the bottom wall portion 60 of the housing I structure 52. The vertical grooves or recesses 64 s: have fixedly received therein elastic elongated con-7~ tact elements 66 which are passed through the apertures :~ 10 in the bottom wall portion 60 of the housing structure 52 and the apertures in the mother board 54 and which . project outwardly from the outer face of the bottom ¦ wall portion 60 of the housing structure 52~ though not shown in Fig. 2 i 15 The side wall portions 56 and 56' of the housing :structure 52 are further formed with vertical grooves : 68 and 68', respectively, wbich extend from the upper ends of the respective inner faces of the side wall ~ portions 56 and 56' to the upper face Or the bottom wall portion 60, The bottom wall portion 60 of the ~ boosing structure 52 is formed with a lateral slot 70 t~ which is laterally in alignment wi~h.. the vertical grooves 68 and 68' in the side wall portions 56 a~d 56~.
¦ For the reason to be explained later, the base portion ~ 25 6~ of the housing structure 52 is located to be offset ' , ~
_ 14 -i 054Z3,6 from the position ali~ned with the vertical grooves ~8 and 68' and the lateral slot 70 ~o that the slot 70 is open at the lower end of the bottom wall portion P 60. On the other hand~ the mother board 54 is formed with a slot 72 which is located in alignment with the lateral slot ? in the bottom wall portion 60 of the I housing structure 52 to be mounted on the mother board 54. As seen in Fig. 2, the slot 72 formed in the '' mother board 54 ig reduced toward the lower end of the mother board 54, vi~., away from the lower wall i' portion 60 of ~,he housing structure 52 which is to be mounted on the upper face of the mother board 54.
The vertical grooves 68 and 68~ in the side wall portions 56 and 56~ and the lateral slot 70 in the bottom wall portion 60 of the housing structure 52 and the slot 72 in the mother board 54 are adapted to receive therein an elastic retainer member 74 which i9 i to hold the printed circuit board 20 in a predetermi.ned ¦ fixed position relative to the housing structure 52.
The retaining member 74 is constructed by an elastic plate of~ for example, metal or plastics and has~a generally Y-shaped configuration which is composed, in ~ an unstressed condition shown in ~ig. 3, of a pair of }~i spaced parallel side arm portions 76 and 76 ~ extending (~ 25 jointly from a lateral intermediate portion 78 and i' ' .

~ 15 -~,os~236 ;

; formed with projection 80 and 80', re~pectively~ at their f`ree.ends. The projections 80 and 80~ are protruded lateral].y inwardly from the re.~pective side arm portions 76 and 76' and are spaced apart ~`rom each other a distance which is slightly smaller than the thickness of the printed circuit board 20 when the i retainin~ member 74 is in the un~tres~ed condition illustrated in Fig. 3. The side arm portions 76 and 76' are elastically deformable toward and away from ; 10 each other in lateral direction of the retaining member 74 about the lateral intermediate portion 78 when pressed laterally inwardly and outwardly. The side arm ~ e,hqth5 ~
portions 76 and 76~ have ~ le~gth which ~ subs-tantially ' equal to the depth of the vertical groove 58 in the j J5 housing struoture 52 as will be seen from Fig. 2. The ` retaining member 74 further comprises a bifurcated catch portion 82 which extends in a direction oppo~ite to the side arm portions 76 and 76l through a longitudi-nal intermediate portion 84 integral with the lateral intermediate portion 78. The catch portion 82 is formed with an elon~gated recess 86 extending from the lohgi-tudinal intermediate p.ortion 84 and terminating and opening at the leading end of the catch portion 82.

The catch portion 82 is thus di~ided into a pair of '25 spaced parallel limb~ 88 and 88' extending from the ' .

~054Z36 longitudinal intermediate portion 8l~. The limb~ 8 and 88' arq elastically deformable toward and away from each other in lateral direction of the retaininS
member 74 about the longitudinal intermediate portion 84 when pressed laterally inwardly and outwardly.
The limbs 88 and 88' are formed with first laterally outwardly stepped edges 90 and 90',respectively, located close to the longitudinal intermediate portion 84 and second laterally outwardly stepped edges 92 ~, lO and 92', respectively, which are located close to the leadin~ ends of the limbs 88 and 88'. If desired, the lateral intermediate portion 78 may be formed with a recess 78a in itY lateral edge opposite to the longitudinal ~e,c~ss B intermediate portion 84 as shown. The ~dgo-78a prefer-ably has a wid-th which is substantially equal to the thickness of the printed circuit board 20 to be mounted I on the connector assembly~ for the reason which wlll be understood as the description proceeds.
The elastic retaining member 74 thus configured in the unstressed condition is press fitted to the housing structure 52 and the mother board 54 in such a manner that the side arm portions 76 and 76' are-at leas-t partly received in the vertical grooves 68 and 680~ in the side wall portions 56 and 56', respectively, of the housing structure and that the limbs 8B and 88' of the catch - -lOS4Z36 portion 82 are closely received in the slot 72 in the mother board 54 so that the housing structure 52 and the mother board 54 are closely fastened to each other , by means of the catch portion 82 of the retaining member 74 as seen in Fig. 2. The lateral intermediate portion 78 of the retaining member 74 is held in contact with the upper face of the bottom wall portion 60 of the housing structure 54 whilst the longitudimal intermediate portion 84 is closely received in the 1 lateral slot 70 in the bottom wal:l. portion 60 of the howsing structure 52. The lower face of the bottom wal.l portion 60 of the houqing structure 52 is slightly qpaced apart from the upper face of the mother board 54 bacause of the base portion 62 located between the bottom wall portion 60 of the housing citructure 52 and : the upper face of the mother board 54. The first laterally outwardly stepped edges 90 and 90' of the limbs 88 and 88~ constituting the catch portion 82 of the retaining member 74 are thus held in close contact s 20 with the lower face of the bottom wall portaon 60 of the housing structure 52 and, like~isq, the secor~d laterally outwardly stepped edge~ 92 and 92' of the s limb i 88 and 88~ are. held in close contact with the . lower face o~ the mother board 54 with the respective leading end portiorls of the limbq 88 and 88' projecting ~ 18 _ .

i ~054Z;~6 outwardly from the lower face of the mother ~oard 54.
For th,e purpose of assembling the retsinirl~ member 74 into the above described position in the housing '5 structure 52 and the mother board 54 which are initially separate from each other, the retaining member 74 is first inserted from over the housing structure 52 into the elongated groove 58 in the housing structure 52 and ; is downwardly guided along the grooves 68 and 68 l in the side wall portions 56 and 56 ' of the housing structure ; 10 52 until the limbs 88 a~d 881 of the catch portion 82 are brought into abutting engagement with the bottom wall portion 60 of the housing structure 52. The limbs 88 and 88 ' are then pressed laterally inwardly so as to be elastically deformed toward each other and are t 15 thus passed through the lateral slot 70 in the bottom wall portion 60 of the housing structure 52 until the lateral intermediate portion 78 is brought into contact with the upper face of the bottom wall portion 60 of ¦, the housing structure 52 and at the same time the first 20 laterally outwardly stepped edges 90 and 90' of the b~ limbs 88 and 88 ~ forming the catch portion 82 become flush with the lower face of the bottom wall portion 60 ',~ of the housing structure 52 with the longitudinal inter-mediate portion 84 received in the lateral slot 70 in ) 25 the bottom wall portion 60. The limbs 88 and sa l of the ., .
. - 19 -~054Z36:

catch portion 8~ are thereafter inserted, ~till in ttle laterally inwardly pressed condition, through the ~:lot 72 in the mother bo~rd 54 until the ~econd l~terally outwardly stepped edges 92 and 92' of the limbs 88 and 88' become flu~h with the lower face Or the mother board 54 with the leading end portion~ of the limbs 88 and 88' projecting outwardly from the lower face of the mother board 54. When the limbs 88 and 8~' of the catch portion 82 are relea~ed from the pressure~ urging i 10 the limbs ]aterally inwardly~ then the limbs 88 and 8e' are allowed to resume their initial positions and have the first laterally outwardly stepped edges 90 and 90' held in close contact with the lower face of the bo~tom wall portion 60 o~` the housing struct~re 52 and the second laterally outwardly stepped edges 92 and 92~ held ~ in close contact with the lower face of the mother board Y 54 as shown in Fig. 2.
When the connector assembly is thu~ complete with the retaining member 74 engaged by the housing structure 1 20 52 and the mother board 54, the printed circuit board 20 i~ forced .in between the inward projections 80-and 80' ~ of the side arln portiohs 76 and 76~ of the retaining ¦ member 74 against the opposing force~ reY~ulting from the ' elasticity of the side arm portions and is downwardly ,~ 25 moved until the end o~ the contact-carrying ed~e portion r ~.os4236 of the printed circuit board 20 i~ receive(l I)y the lateral intermediate portion 7~, preferably in tlle recess 78a in the intermediate portion 78 of` tl-e retaining member 74 as ~een in ~ig. 2. The printed circuit board 20 i9 in this mann~r closely hel~J in a })recletermine~ fixed position relalive io tl~e l`OIII~CC~
assembly, having its contact-carrying edge porti~n pressed between the inward projection~ 80 and 80' of the side arm portions 76 and 76', re~pectively, of ~d~ ~ lo the elastic retaining member 74. The con~u~tive-contacts carried on the edge portion of the printed circuit board 20 are thu~ respectively maintained in contact with the individual contact element~ carriHd on inner faces of the side wall portions 5G and 5~' L5 f the hou~ing structure 52, Fig. 4 illu~trates another preferred embodiment of the connector assembly according to the pre~ent invention. The embodiment ~hown in Fig. 4 is a modifi-~ cation of the embodiment thus far described with reference to Figs. 2 and 3 and is thus composed of a housing structure 52, a mother board 54 and a retainiJlg member 74 all of which are con~tructed and arran~ed e~sentially similarly to their respective counterpart in the embodiment shown in Fig. 2. The eml~odiment shown ~5 in Fig. 4 is, however, adapted for u~e with a printed _ 21 -~OS4Z36 circuit board 20' which has an aperture 9~ forme(l in it~ contact-carrying edge portion f'or rece.iving ~helein tip portions of the inward projection~ 80 and 80' of the side arm portions 7~ and 7G~ of the eLa~t LC retain-ing member ~1l as illustrated. 'rhe aperLure 9ll in tllocontact-carrying edge portlon of the prin-ed circ~
board 20' is, for this purpo~e, in a predetermined position relative to the retaining member 71l or, more exactly, to the inward projections 80 and 80' of the side arm portions 76 and 7~ of the retaining member 74 affixed to the housing structure 52 and the mother board 51t. When the contact-carrying edge portion of the printed circuit board 20' is held .in a prede~ermined fixed position relative to the retaining member 74 in the connector assemblyl the inward projections oO and 80' of the side arm portions 76 and 76' of the retain-ing member 74 are partly received in the aperture 94 ~in the printed circuit board 20~ and thus preve.nt the printed circuit board 20' ~rom being dislodged or dis-located from the predetermined position thereof in bothvertical and longitudinal directions of the hou~irlg structure 52. Where the printed circuit board 20' is fitted to the connector assembly by manual operatiollY, the operator will be capab.le of easily perceivillg, at lliS finger-tips, the proper engagement achieved betweer lQ54Z3~

the printed circuit board 20' and the retaining member 71t by the snap action~ of the projection~ 80 and 80' received in the aperture ~4 in the circuit board 20'.
The printed circuit boards 20 and 20' for use with the embodiments shown in Figs. 2 and 4 h~ve been ~d ~
B a~sumed to have the ~ ~e-contacts carried on both face~ of each of the circuit boards. If, however, the printed circuit board 20 or 20' i~ provided with .~ ~d ~
con~uo*ivo contacts carried on only one of the faces thereof so that the housing ~tructure 52 ha~ the contact element~ 66 carried on the inner face of only one of the side wall portions 56 and 56~ thereof~ then the retaining member 74 for holding the printed circuit 15~ board 20 or 20' may be 90 configured as to have one of it~ ~ide arm portion~ 76 and 76~ cut off or terminated halfway, Fig, 5 illustrate~ an example of such a retaining member which is now de~ignated by 74~ and ~`- Fig~. 6 and 7 illustrate embodiment~ of the connector assembly in which a ~on-apertured printed circuit board 20 or an apertured printed circuit board 20' is held in position by means of the retaining member 74'.
A~ ~hown in Fig. 5, the retaining member 74' ha~ side arm portions 76 and 76a which are jointly bifurcated 25 ~ from a lateral intermediate portion 78. The lateral ~os4236 intermediate portion 78 is shown to be formed with 8 lateral recesY 78a having a width substantialJy equal to the thicknes4 of the printed circuit board to be received by the retaining member 71l'. One Rid~ ~rm po.rtion has a length gubstantially equal. to the length of the vertical groove 68 in the side waLI portion sfi of the housing structure 52 as will be seen in r~ig. G
or 7 and i4 formed with an inward projection 80 at its upper end similarly to each of the side arm portions 76 and 76' in each of the embodiments chown in Figs. 2 and 4. The other side arm portion 76a i4 shorter than the above-mentioned side arm portion 76 and has a plain ~ree end which is located halfway of the length of tlle vertical groove 68~ in the side wall portion 56' of the housing :52 when the retaining member 74l is assem-bled to the hOusing structure 52 as shown in Fig. 6 or ~;;7. The retaining member 74' i4 in other respects similar.to the retaining member 74 illustrated in Fig.
~ 3, thu4 having a bifurcated catch portion 82 extending in a direction opposite to the side arm portions 76 and 76a fro~ the lateral intermediate portion 78 through a longitudinal intermediate portion 82. As seen in Fig.
5, the catch portion 82 of the retaining member 74' is also divided by an elongated slot 86 into a pair of spaced parallel limb~ 88 and 88~ which is formed with _ 24 -los4~z36 first stepped edges 90 and 90' and second ~tepped edges 92 and 92'. The retaining member 74' which i~
configured in this fashion may be used either with a Don-apertured printed circuit board 20 as in the embodi~ent ~hown in Fig. 6 or with an apertur~ll prinled circuit board 20' formed with an aperture 91~ in its contact-carrying edge portion as illustrated in l~ig. 7.
In each of the embodiments shown in Figs. 6 and 7, ~ it is assumed that the housing structure 52 ha~ contact elements 66 c~rried in the vertical grooves 64 in the ~side wall portion 56~ alone of the housing structure 52. In whichsoever arrangement of the embodiments -shown in Figs. 6 and 7~ the side arm portions 76 and 76a of the retaining member 74~ are closely received between the lower parts of the inner faces of the side ~wall portions 56 and 56' of the housing structure 52 and at the same time the lateral intermedlate portion 70 of the retaining member 74~ i8 cloQely received on the upper face of the bottom wall portion 60 of the housing structure 52. When, thus, the non-apertured printed circuit board 20 is inserted into the elongated groove 58 in the housing structure 52 and i8 fitted to the retaining member 74~ in the embodiment illustrated in Fig. 6, the longer side arm portion 76 of the re-taining member 74~ received in the vertical groove 6a 105423~i in the side wall portion 56 of the housing structure 52 h~R its inward projection 80 held in pre~sing engagement with one face of the printed circuit board 20 which has the end of its contact-carrying edge portion received on the recess 78a in the lateral intermediate portion 78 of the retaining member 74~.
:~ The ~horter ~ide arm portion 76a of the retaining ~member 74' terminates halfway in the vertical groove ~68' in the side wall portion 56' of the housing ~tructure 52. The printed circuit board 20 i9 tllUS
.
ela~tically pre~ed over the other face of its contact-carrying edge portion against the contact elements 66 on the inner face of the side wall portion 56' of the housing structure 52, On the other hand, the aperture~
15 ~ printed circuit board 20' fitted to the retaining member ;74' in the embodiment illustrated in Fig. 7 has captured in its ~perture 94 a portlon of the inward projection 80 of the longer ~ide arm portion 76 of the retaining member 74~. The pri~ted circuit board 20' i~ therefore not only èlastically pres~ed agai~st the contact element~
66 on the inner face of the ~ide wall portion 56' of the hou~ing structure 52 but prevented from b0ing diRlodged or di~located from it~ predetermined initial position relative to the hou~ing ~tructure 52.
Fig~. 8 and 9 ill~trate modifications of the ~054236 elastic retaining member 74 incorporated in each of the embodi-ments thus far described with reference to Figs. 2 and 4. The modified retaining members, now designated by 74a and 74_ res-pectively, are thus adapted each for use with a printed circuit board having edge contacts carried on both surfaces thereof.
The retaining member 74a illustrated in Fig. 8 is characterized in that the side arm portions 76 and 76' bifur-cated from the lateral intermediate portion 78 are formed with teeth 96 and 96', respectively, on their laterally outer edges and that the limbs 88 and 88' constituting the catch portion 82 are void of the previously mentioned first laterally outwardly stepped edges and are thus formed only with laterally outwardly stepped edges 92 and 92', respectively, which are located close to the leading ends of the limbs 88 and 88'. When the retaining member 74a thus configured is assembled to the housing structure 52 and the mother board 54, the teeth 96 and 96' are brought into close contact with those inner faces of the side wall portions 56 and 56' of the housing structure 52 which form the grooves 68 and 68' respectively and at the same time the laterally outwardly stepped edges 92 and 92' are brought into close contact with the lower face of the mother board 54, 1054Z3~
though not shown in Fig~ 8. It is app~rent that the teeth 96 and 96i may he repLac~d by ally oth~r l~orm.s of roughened surfaces and may be formed aLso o~l lhe ~ e ar~ portions 76 and 76' of the retaining momher 7~l having the conf`i~llration il.lustraLed itl l'`ig. 3 .il`
desired.
On the other hand~ tlle retaining member 74b sho~n in Fig. 9 has side arm portions 7~ and 7C' silllilar to those of the retaining member 74 shown in l~`ig. 3 and d.iffers from the retaining member 74 in that the laterally outwardly stepped edges 90 and 90' formed on the limbs 88 and 88~ in the vlcinity of the longi-tudinal intermediate portion 84 are replaced ~it.h t.~eth 98 and 98', respectively. When the retaining member 74b thus formed is assembled to the housing structure 52 and the mother board 54, the teeth 98 and 98~ on the outer edges of the limbs 88 and 88' constituting the catch portion 82 are partly in contact with the wall surfaces defining the lateral slot 70 in the bottom wall portion 60 of the housing structure 52 and partly in contact with the wall su.rfaces defining the slot 72 in the mother board 54, though not shown in Fig. 9. It is apparent that the teeth 98 and 98' may be replaced by any other forms of roughened surface and may also be formed on the limbs 88 and 88' of the 1054Z3ti retaining member 74a shown in ~`ig. 8, if desirel1.
t~`ig. 10 illu~trate~ ~ mo(lifi~.ltion oi` the r~-taining member 74~ shown in Fig. 5. Tt1e ms~dif`i~d retaining member, designate(l by 74'a~is thus adapted for use witb ~ printed circui1 I)ourd 1~avir1g colnlllctive contacts car~ried on only one o1` the sur~ ces ol tl1o board as in each Oe the embodimel1ts descrit~ ith reference to Figs. 6 and 7. In contrast to the retaining member 74~ shown in Fig. 5, the modified retaining member 74~a is characterized in that the longer side arm portion 7~ thereof is provided with a projection lO0 which projects angularly upwardly ~`rom one face of the side arm portion 7t~ and which is ~hus elastically def`ormable toward and away lrom the face ~ of the side arm portion 76 about the lower end of the projection 100. As ~een in Fig. ll which illustrates a condition in which the retaining member 74'a is f1tted to the housing structure 52, one of the side walls defining the vertical groove 68 therebetween in the side wall portion 56 of the hou~ing structure 52 is stepped as at 68a away from the other of the side waLls defining the groave 68 in the longitudinal direction of the side wall portion 5~. The stepped wall 68a is located to be in e~gagement with the upper leading end of the projection 100 on the side arm portion 76 of the retaining Ineml)er 7/l'a as showll in Fig. ll when the side arm portion 7(~ of the relaillirlg member 74'a ie slipped along the vertical groove ~8 in the side wall portion 56 into a position to have the retaining member 74'a snugly f`iLted to tli~ hollsillg structure 5~. The retaining member 7ll'a thllY asse~ led to the housing structure 52 is prevented from t)eing vertically moved relative to the housing structure 52 by reason of the engagement between the projection lOO
on the side arm portion 7~ o~ the retaining member 74'a and the stepped wall 68a defining part of the vertical groove 68 receiving the side arm portion 76. ~t is apparent that the entity like the proJection LOO
provided on the longer side arm portion 76 of the retaining member 74'a may also be provided on the shorter side arm portion 76a or on one or each of the side arm portions 76 and 76' of each of the retaining members 74, 74a and 74b shown in ~igs. 3, 8 and 9, respectively, if desired.
In each of the embodiments thus far described with reference to ~igs. 2 to ll, the laterally outwardly stepped edges 92 and 92' formed on the leading end portions of the limbs 88 and 88', respectively, of the catch portion 82 of the retaining member have beeJI
assumed to have flat surfaces which are perpendicular ~054236 to the limbs 88 and 88' and which are accor(lirlgly brought into contact with the lower J`ace ol` the molher board 54 over their entire areas. ~r pret`erred, how-ever, the stepped edges formed on the limb~ ~8 and 88' may be inclined laterally downwardly a~ in(lica~e(l a~
102 and 102~ in l~1ig. 12 so that the stepped edges lO~
and 102' are in contact with the edge~ defining the opposite ends of the slot ô2 in the mother boar~l 5l~.
Thus, close engagement hetween the limbs 88 and 88' of the catch portion 82 of the retaining member can be achieved easily and assuredly even though the si~es of the limbs 88 and 88' of the retaining member manu-factured on a large-scale commerciaL basix are xtrictly not matched with the side of the xlot 72 in the mother board 54.
~ `ig. 13 illustrates still another preferred embodiment of the connector a~xembly according to the present invention. Similarly to each of the embodi-ments which have thus far been described, the embodi-ment ~hown in ~ig. 13 comprlses a housing structure 52and a mother board 54. The housing structure 52 is composed of spaced parallel side wall portions 56 and 56' forming an elongated groove 58 therebetween and a bottom wall portion 60. Each of the side wall portions 56 and 56~ is formed with vertical grooves or recesses ~OS423G

~ll carrying therein elastic contact elemellt~ b6, respectively, as previously mentioned in connection with the embodiment illustrated in ~ig. 2.
In the embodiment shown in ~`ig. 13, the si(le wall portion~ 56 and 5G' of the hollsirlg structule 5" are further formed with vertical grooves 10/l anl IOll', respectively, which extend between the upper and lower ends of the inner faces of the side waLl portions 56 and 56~. While the vertical grooves 68 and 68' formed 10 in the side wall portions 56 and 5C' of the housing structure 52 incorporated into each of the embodinents thus far described extend straight in parallel to the inner faces of the ~ide wall portion~ 5G and 51) ', each of the vertical grooves 104 and lO4' in the side wall portions 56 and 56' of the housing structure 52 in the embodiment shown in Fig. 13 ha a bottom surface having an intermediate portion which is curved lateraLly out-~; wardly from the elongated groove 58 in the housing ~structure 52, viz., toward the outer face of the side wall portion in which the groove is formed. On the other hand, the bottom wall portion 60 of the housing structure 52 shown in Fig. 13 is formed with a lateral slot 106 which merges at its oppo~ite ends into ~he lower ends of the above-mentioned vertical grooves lO4 and 104' in the side wall portions 56 and 56'. The ~os4236 vertical grooves 104 and 1.04' in the si-le waLI portions 56 and 56' are thus open at the lo~r end ot` t:lle t-ott.om wall portion 60 through the opposite endx. of~ the lateral slot 10~ in the bottom wall portion Go. I`~e opposite ends of the lateral slot .106 in the bottonl wall porl:i.on 60 are defined by wall portions :lO~ and l()~' wtlich ~ro-trude toward each other, viz., laterally inwardly of the housing structure 52. The mother board 54 i-~ ~`ormed with a pair of holes 110 and 110' which are respectively L0 located substantially in alignment with the opposite ends of the lateral slot 106 in the bottom wal.l po-tion ~dj,~c~ h~
~J 60, vi~., arr~oYimately be:lo~ the lower ends of the vertical grooves 104 and 104' in the ~ide wa.l.L portions 56 and 56~, respectively~ of the housing structure 52 which is to be mounted on the mother board 54.
The embodiment shown in Fig. 13 further comprixes : an elastic retaining member 112 to hold a printed circuit board 20 in a predetermined fixed position relative to the housing structure 52. The retaining member 112 is constructed of an elastic metal wire such as for example a music wire and has a generally M-stlaped contigllration consisting, in an unstressed condition shown in Fig.
14, of a pair of intermediate portions 114 and 114' merg:ing into each other through a semicircularly curved middle portion llG and extending substantiaLl.y or at ~oS4Z36 least partly in parallel with each other, a pair of side arm portion~ 118 and 11~' turned backh~ar-lly ~`rom the leading ends of the intermediate portions llll anll 114~ and anguLarly spaced apart sidewise outwardly from the intermediate portions .L14 and 114', respec-tively, a pair of snap portions 120 and 120~ semi-circularly curved laterall.y inwardly from the leadin~y ends of the side arm portions 118 and 118', re~pectively, and end portions 122 and 122' sidewise bent or cllrved 1.0 laterally outwardly from the leading ends of the snap portions 120 and 120', respectively. l`he snap portions 120 and 1201 are curved or protruded conformingly to the surfaces of the ahove-mentioned protruded wall portion~ 108 and 108~ respective.ly, defining the lateral slot 106 in the bottom wall portion 60 of the housing structure 52. For the reason to be explained later, furthermore, the end port.ions 122 and 122' of the retaining member 112 are preferably semicircularly turned back from the leading ends of the snap portions 120 and 120l, respectively, as shown in Fig. 14.
//~
The elastic retaining member -~4 thus confi~yured in the unstressed condition is press fitted to the housing structure 52 and the mother board 54 in such a manner that the snap portions 120 and 120' are closely received on the surfaces of the protruded wall portions ~C)54Z3~
1~
108 and 108' of` the housing struct:ure 52 a~ ~itll Ihe end portions 122 and 122' partly pas~ed tllro~ Ih~
holes 110 and 110~ in the mother board 54 as seell in ~ig. 13. The previously mentioned curved bottom ~ o ~
surfaces ~ the ~ertical grooves Lo4 and l04' in the side wall portions 5G and 5~)', respectively, ol the housing s-tructure 52 are thus at least partLy hel~l in pressing engagement with the side arm portions 118 and 118', respectively, of the retaining member 1l2.
The intermediate portions 114 and 1l4' of the retaining member 112 are consequently forced toward each other in the lateral direction of the housing structure 52 and at the same time the end portions 122 and l'2' Or the retaining member 112 have their respective tips forced against the lower face of the mother board 54 by re~son of the elasticity of the retaining member 112. The housing structure 52 and the mother board 54 are thus closely fastened to each other by engagement between the retaining member 74 and the mother board 54 without use of any extra fastening means.
To have the retaining member 112 fitted to the housing structure 52 and the mother board 54 which initially are separate from each other, the retaining member 112 is first inserted into the elongated groove 58 in the housing structure 52 from the top or bottom ~ 35 -~oS4Z36 tl ~ 0 0 ~
B ~ the ~ o that the ~ide ~rm l~ortiolls J18 and 118' of the retaining member 112 are received ~ ~ r rn 1'~
on the curved bottom sùrfaceg ~f the vertical grooves 104 and 104' in the side wall portions 56 and 56', ~ respectively, and at the same time the snap portions 120 and 120' are received on the protruded wall portions 108 and 108', respectively, of the housing structure 52.

When the retàining member 1l2 is ~`itted to the l)ollsirl~

structure 52 in this fashion, the end portion~ 122 and ....
10 ~ : 122' of the retaining member 112 project downwardly out of the lateral slot 106 in the bottom wall portion 60 of the housing ~tructure 52~ ~`he end portions 122 and 122' of the retaining member 74 are then pressed ~ ~ toward each other against the opposing force re~ulting 15~ from the elasticity of thereof and are inserted through the holes 110 and 110'~ respectively~ in the mother board ~ 54. When the retaining ~ember 112 is released from the : ~ pressing effort which ha9 been applied to the end portions 122 and 122~ *hereof, the retaining member 112 is closely ",, ~,:
20 '~ engaged by th,~e mother board 54 which is as a consequence ~tightly fa-~tçned to the bottom wall portion 60 of the housing structure 52.
When the connector assembly is complete with the retaining member 112 engaged by the housing structure 52 and the mother board 54, the printed circuit board 20 is _ 36 -~,o54Z36 forced in between the intermediate portion~ 1 14 and 114' of the retaining member L12 until the end ol` the contact-carrying edge portion of the circuit bo~rù 20 is brought into contact with th~ inner face oJ the rounded middle portion 116 oL` the rctaillin~ loeml-)er ll' as shown in Fig. 13. The printe(l circuit board 20 is thus closely held in position having its contact-carryinS
edge portion pressed between the intermediate portions 114 and 114' of the retaining member 112 so that the ~Jy~ lo cond~lctivc contacts carried on the edge portion are maintained in close contact with the contact elemeJIts 66 carried on the respective inner f`aces of the side wall portions 5~ and 5Gl of the housirlg strllcture ~2.
Fig. 15 illustrates a modification of the embodi-ment which has been described with reference to Fig~.
13 and 14. Referring to Fig. 14, the connector as~embly -~; herein shown is adapted for use with a printed circuit board 20' which is formed with an aperture 94 in its ~ contact-carrying edge portion and comprises an elastic ` retaining member 112'. The elastic retaining member 112' i~ configured largely similarly to the retaining member 112 shown in ~ig. 14 and has intermediate portionq ll4 and 114', a rounded middle portion ILG inter-connecting the intermediate portions 114 and lL4', side arm portions 118 and 118' extending sidewise outwardly ~ 37 -~Os4~36 of the intermediate portions llll and :L~ , respectively, snap portions 120 and 120~ laterally in~ardLy curved from the leading ends of the side arm portion~ 3 and 118', respectively~ in conformity to the sur~`ace~ of the protruded wall portions lo8 an~ 108' o~ e l~ousin$
structure 5", and end portions 1"" an(l :I""' lat.elaLl.y outwardly cur~ed from the ~nap portions 1"0 an<t L20 , respectively. In addition to these portions of the retaining member 112 shown in ~ig. 14, the retaining member 112~ of the embodiment shown in Fig. 15 has inward protrusions 124 and 124' in its intermediate p~tru,s iOhs portions 114 and 114', respectively. 'rhe projoctions 124 and 124' are sub~tantially semicircularly curved laterally inwardly toward each other and are located 15 to be in alignment with the aperture 94 in the printed circuit board 20 which is held in the position having its contact-carrying edge portion pressed between the ntermediate portions 114 and 114' of the retaining ~ ~ member 112'. When the contact-carrying edge portion of the printed circuit board 20 is thus captured between the intermediate portions llll and 114' of the retainirlg member 112~the protru~ions 124 and 124' respectively formed in the intermediate portion~ 114 and 114' are closely received in the aperture 94 and thus prevent the printed circuit board 20 frool being dislodged or ~,os4236 dislocated from its predetermined .initial positi(ln relative to the housing structure 52. Wl~ere the printed circuit board 20 is fitted to the connec~or pr ~t~s~ns assembly by manual operation, the -projoction~ 124 and 124' formed in the retaining mem~er 112' will facilitate the operator to perceive proper engagement achieved between the printed circuit board 20 and the retaininS
member 112' by the ~nap actions of the protrusiolls 124 and 124' received in the aperture 94 in the circuit board 20.
Fig. 16 ill.ustrates sti:ll another preferred embodiment o.f the connector assembly according to the present invention. In the embodiment herein .~hown, . the housiny; ~tructure 52 having side wall portions 5t', and 56' and a bottom wall portion 60 has elastic contact elements (not shown) carried on the inner face of only one side walL portion 56 thereof and is thus : ~ assumed to be used for the mounting of a printed circuit ~dq~
board 20 having ~ contacts (not sho~in) printed on only one of the surfaces thereof. The housing structure 52 has formed in its side wal.l portion 56' a vertical groove 126 extending between the upper and lower ends of the inner face of the wall portion 5G l and in its bottom wall portion~)a lateral slot 128 having one lateral end joining the vertical groove 126 and the ~ 39 -1054Z3~;

other lateral end defined by the surface ol` a ~ul)-stantially semicircularly protruded wall portion 130.
On the other hand, the mother board 54 is formed with an aperture 132 which iY located in a.lignment with the vertical groove 126 in the side wall portion 5G ~ and accordingly with one end of the sl.ot 12~ in the l~ott.om wall portion 60 of the housing structllre 52. 'I`he housing ~tructure 52 and the mother board 54 thus ~ configured are combined together by means of a retain-ing member 134 which has an unstressed condition illustrated in Fig. 17. The retaining member 134 is formed of an elastic metal wire such as a music wire and comprises a substantial.Ly straight side arm portion 136, a curved side arm portion 138 merging out ol` the ~ straight side arm portion, a laterally outwardly curved :~ end portion 140 extending from the leading end of the straight side srm portion 136 and A laterally inwardly :: curved semicircular end portion 142 extending from the .
leading end o~ the curved side arm portion 138. The ~0 semicircular end portion 142 iD curved in conformity to the surface of the semicircularly protruded wall 130 defining one end of the slot 128 in the bottom wall portion 60 of the ho~sing structure 52. The retaining member 134 configured in this fashion is fitted to the housing structure 52 in such a manner that the straight side arm portion 136 i~ received p~rtly in the vertical sroo~e 126 in the ~ide wall portion ~ n(l partly in one end of the lateral slot 128 in tlle bottom wall portion 60 with the laterally outwardly curved encl portion 140 projecting out of the lower elld of the bottom wall portion 60 of the hou~ing ~tructure 52. 'rhe laterally inwardly curved end portion l/~2 of the retaining member 134 is closely recei~ed on the surface of the semicircularly protrucled wall portion 130 defining the other end of the lateral slot 128 in the bottom wall portion 60 so that the curved side arm portion 138 of the retaining member 134 extends over the inner face of the side wall portion 56 of the hou~ing structure 52. The retaining member 134'is ther fitted to the mother board 54 in such a manner that the lowermost part of the straight side arm portion 136 is passed through the aperture 13Z in the mother board 54 and the laterally outwardly curved end portion 140 projects downwardly from th,e lower face of the mother ~o board 54, as seen in Fig. 16. The printed circuit board 20 is held in position between the inner face o~`
the side wall portion 56 of the housing structure 52 ancl the curved side arm portion 138 of the retainin$
member 134 as illustrated in Fig. 16 so that one sllrf`ace ~5 of the circuit board 20 i~ ~paced apart from the inner ~o54Z36 f~ce of the side wall portion 56' of the housing structure 52 and the other surface, vis., the contact-carrying surface of the board 20 is in pressing contact with the contact elements (not shown) on the inner face of the side wall portion 56 of the housing structure 52.
Fig. 18 illustrates still another preferred embodiment of the connector assembly according to the present invention.
The connector assembly herein shown is also assumed to have con-tact elements ~not shown) carried on only one of its side wall portions 56 and 56' of the housing structure 52 and is thus adapted for use with a printed circuit board 20' having contacts printed on only one surface thereof and formed with an aperture 9~ in its contact-carrying edge portion. The side wall portion 56' of the housing structure 52 has formed at its top a generally square-shaped recess 144 which is open to the elongated groove 58 between the inner faces of the side wall portions 56 and 56'.
On the other hand, the bottom wall portion 60 of the housing structure 52 is formed with a slot 146 which is aligned with the top recess 144 in the side wall portion 56' in the lateral dir-ection of the housing structure 52. The housing structure 52 thus 105~236 configured is fitted with a retailling meml:~er l1l~3 whicl is formed of an elastic metal. wire and wt~icll i~ colll-po~ed of an intermediate portion 1~0 having a l a t erally outward protr-lsion 152 adapted to he partly received in the aperture 94 in the prlnted circuit ~)oard ~0, an 1~
B upper end portion ~ substantially perl~erl(liclllarly bent or curved from the intermediate portion l50 an(~
is adapted to fit into the top recess 141t in the side wall portion 56', a snap portion 156 laterally out--lO wardly curved from the lower end of the intermediate portion 150 in a direction laterally opposite to the protrusion 152 and configured to be in conforlllity to the wall defining the end of the slot 146 in the bottom wall portion 60 of the housing structure 52 and a lower L5 end portion 158 substantialLy perpendicularly curved f`rom the lower end of the snap portion 156. The re-taining member 14~ configured in this fashion is fitted to the housing structure 52 in such a manner that the laterally outwardly bent or curved upper end portion ~o 154 thereof i9 received in the top reces~ 144 in the side wa~l portion 56' and the snap portion l5(, i~ pa~e-l through the slot 146 in the bottom wall portion Go ot`
the housing ~tructure 52 with the lower end port.ion l5 at least partly in contact with the l.ower face of the bottom wall portion 60 of the housing structure r,2.

- 43 ~

~,os4236 When the apertured printed circuit board 20' :is held in a predeter~ined relative poqition relative to t,he housing structure 52 illustrated in Fig. 18, the laterally outward protrusion 152 of the intermediate portion 150 of the retaining member 148 is partly received~in the ap0rture 9It in the printed circuit board 20' which consequently haq its contact-c~rrying edge portion pres~ed a$ain~t the ela~tic contact elements (not qhown) carried on the inner face of the side wall portion 56 of the hou~ing structure 52.
Under these condition~, the upper end portion 154 of the retaining member 148 has its end .in pressing contact with the l~terally outer end ~urface defining the reces~ 144 ~o that the intermediate portion,:L50 f the retaining member 148 i~ at lea~t in part held in pres~ing engagement with the printed circuit board 20', If de~ired~ the rece~s 144 formed .in the top wall of the side wall portion 56' of the housing structure 52 may be ~tepped laterally outwardly in the side wall portion 56~ in the longitudinal direction of the wall portion 56', having laterally outer ends defined by fir~t and qecond wall ~urfaces 144a and 144b located at different di~tance~ from the laterally inner end of the side wall portion 56~, as ~een in Fig. 18a. In the arrangement shown in Fig. 18a, it i~

los4Z36 as~umed that the first wall surface 144A i~ located at a smalle,r distance from the laterally inner end of the ~ide wall portion 56' than the gecond wall ~urface 144b 80 that the pressing force exerted by the retaining member 148 on the printed circuit board 20 can be v~ried B 8tepwiSe ~Ypo~d~t' n~ the relative position of the upper end portion 154 of the retaining member 148 in ~'" the recess 144. If, thus, it i9 desired that the ~ printed circuit board 20' be forced again~t the contact , element~ (not shown) on the side wall portion 56 o~
the housing structure 52 with a relatively large pres-'~ure, the re`taining member 148 should be positioned to ..
have its upper end portion'154 received on the first ~, end surfsce 144a as indicated by full lines in Fig.

~18a. In this instance~ tbe printed circuit board 20' ~ may be'ea~ily removed from the housin$ structure 52 ~ . ,~; .
by moving the upper end port~on 154 of the retaining ' ~ member 148 from the pQsition engaging the rirst end ~,',"surface 144a to the position engaging the ~econd end ,, ,,, - ~
~' ~urface 144b as indicated by broken lines in Fig. 18a.
''If, conversely~ the printed circuit board 20' is desired to be forced a8ainst the contact elements with a reduced pressure, then the retaining member 148 should be positioned to have its upper end portion 154 received on the second end surrace 144b. If desired, , the recess 144 may be formed with three or ev~n more stepped walls ~o as to enable the re-taining member 11l8 to have the printed circuit board 20' forced against the contact elements on the side wall portion 56' with a force which may be adjusted more minutely.
While the retaining member incorporated into each of the various embodiments of the connector assembly according to the present invention has been described and shown to be formed separately of the housing structure, the retaining member may be formed inte-grally with the housing structure, if desired. Fig.
19 illustrates an embodiment of the connector assembly having such retaining means. Referring to Fig. I9, the housing structure 52 is also as~umed to be ~dapted for use with a printed circuit board 20 having contacts (not shown) carried on only one of the surfaces thereof and has a ~ide wall portion 56 carrying elastic contact elements (not shown) on its inner face and a side wall portion 56' spaced apart in parallel from the contact-~o carrying side wall portion 56 for forming an elongatedgroove 58 therebetween. The side wall portion 5G ' is formed with an obtusely bifurcated projection lf)o projecting substantially perpendicularly from the inner face of the side wall por~ion 56l into the elonKated groove 58 between the side wall portions 56 and 5()'.

_ 46 -The bifurcated projection 1.60 i~ co~n~)offed 0~` U ~)~ir of ansular.Ly space.i arm portions I()Oa an(l l(:)0t) eXlelld-ing over the inner f`ace of ~he side wal.1 portiol~ r)( in vertical direction of` the housing ~tructur~ 5 The arm portions l.~Oa and l(>Ob havl3 respect.iv~ l`ree ends which are equally spaced apart irom the inl~3r face of` the ~ide wall portio~l 5G carryinS tlle collluct element~ ~o that the printed circuit boar~ 20 los:i.tioned between the inner f~ce of` the contact-carryin~ siJe wall portion 5G and the bif`urcated projection 1~) of`
the side wall portion 5G as ilLustrated i~ elasticall.y pressed again~t tlle contact elemellts on the siie ~al l portion 56 partly by reason of the el.asl;icity oi` tl~e arm portion~ 1~0~ and 1(01~ of` the pro~jecti.on J()0 on .L5 the side wall portion 5G f`ormed of an eLasti~ nluterial and partly by reason of thé elasticity ol` the contact elelllerltY on the side wall portion 5(~.
Frorn the foregoing description it will now ~e appreciated that the connoctor assembly emL)odyillg tl~e 0 present invention will prove advantageous over prior art connector assemb.lies f`or printed circuit t)oar(l in the following respects:
.I I`he llousing structure can te ea~ily alld t.i~ tly connecte~ to the mother board by the simpLe stols to l`it ~5 the retaining members to the housing structure and the ~ 47 -~054Z36 mother board without aid of any extru fa~tenin~y ~ a~
such as screwq used in a prior art connector asselllL)Iy.
2 The printed circuit board is ela~tically held in a fixed po~itlon relative to the housjng ~tructure by mean~ of the retainin~ members formed of ela~ic material so that the shocks and impact~ whict~ m~y be imparted to the connector assembly are alleviated before they reach the printed circuit board or the shocks and impacts imparted directly to the printed circuit board are ab~orbed by the elastic deformation of the retaining member~. As a consequence, fluctuations in the contuct preYsure between the contact~ orl the printed circuit board and the contact elementa on the hou~ing Ytructure can be le~ ened so that the contact re~istance between the contacts on the circuit board and the contact elements on the housing structure can be maintained substantially constant, This will result in prolonged ~ervice lives of the printed circult board and the connector assembly, ~-o 3 The printed circuit board is prevented from being di~located or dislodged from its initial predeter-mined pO~itiOIl relative to the housing structure by the retaining members tightly engaging the circiut board and the connector assembly.

4 In the ab~ence of any extra fastening means _ 48 -105Ya3~, provided to combine the hou~ins ~tructure and the mother board in a prior art connector assembly, the overall dimensions of the connector assembly Call be reduced to a minimum.
While a variety of preferred embodiment~ o~` tl-e connector assembly according to the present invention have thu~ far been described with reference to the accompanying drawings, it should be borne in mind that such embodiments are merely for the purpo~e of illus-tration of the gist of the present invention and are therefore subject to change and alter~tion if desire~.
Although, for example, each of the embodiments has been shown provided with only one ret~ining member, such is solely for the simplicity of description and illustration and, thus~ each of the embodiments may be provided with a desired number of retaining members each of which is constructed and arranged in a manner herein proposed. If desired, moreover, retaining member incorporated in each of the embodiments thus ,,0 far described may be formed of a conducti~e material and used as a conductor providing electrical connection between the contacts on the printed circuit board and the contact elements on the housing structure of the connector assembly.

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A connector assembly for a printed circuit board having electrical edge contacts on at least one surface of its edge portion, comprising a housing structure having a pair of spaced parallel side wall portions forming theretween an elonated groove which is open at its top end and a bottom wall portion located at the bottom of said elongated groove, at least one of said side wall portions having a plurality of electrical contact elements carried on the inner face thereof, and at least one elastic retaining member for retaining, in use, the printed circuit board to said housing structure, said retaining member being formed separately of and detachably mounted on the housing structure and being at least in part positioned in said elongated groove and in engagement with at least one of the side wall portions of the housing structure for being, in use, in pressing engagement with at least one surface of the contact-carrying edge portion of said printed circuit board and thereby holding the printed circuit board in a predetermined fixed position having said edge contacts respectively in contact with the contact elements on said housing structure.

2. A connector assembly as set forth in Claim 1, further comprising a mother board positioned underneath said housing structure, said retaining member projecting outwardly from said bottom wall portion of said housing structure and in retaining engagement with said mother board for thereby fastening the mother board to the housing structure.

3. A connector assembly as set forth in Claim 2, in which said retaining member has a first side arm portion at least partly in contact with the inner face of one of said side wall portions of said housing structure and a second side arm portion in contact with the inner face of the other of the side wall portions of the housing structure and in pressing engagement with said printed circuit board for holding the printed circuit board in said predetermined fixed position relative to the housing structure.

4. A connector assembly as net forth in Claim 3, in which said retaining member further has a lateral intermediate portion in contact with the inner face of said bottom wall portion of said housing structure for receiving the end of said contact-carrying edge portion of the printed circuit board on the upper lateral edge of said intermediate portion.

5. A connector assembly as set forth in Claim 4, in which said first and second side arm portions of the retaining member extend from said lateral inter-mediate portion along the inner faces of the side wall portions of the housing structure.

6. A connector assembly as set forth in Claim 5, in which each of said side wall portions of said housing structure is formed with a vertical groove extending from the top end of the inner face of each side wall portion, each of said first and second side arm portions of said retain-ing member being at least in part received in the vertical groove in each of the side wall portions.

7. A connector assembly as set forth in claim 4, for use where said printed circuit board has said contacts carried on both of the surfaces of said edge portion, and said housing structure has said contact elements carried on the inner face of each of said side wall portions thereof, wherein said first and second side arm portions of said retaining member are respec-tively in pressing engagement with the opposite surfaces of the contact-carrying edge portion of said printed circuit board for holding the contacts on both surfaces of the circuit board in contact with the contact elements on the inner faces of both of the side wall portions of the housing structure.

8. A connector assembly as set forth in claim 7, in which each of said first and second side arm portions of said retaining member has formed at its free end an inward projection for contacting, in use, each of the surfaces of the contact-carrying edge portion of said printed circuit board.

9. A connector assembly as set forth in claim 8, for use where said printed circuit board has an aperture in its contact-carrying edge, said inward projections of said first and second side arm portions being received in said aperture.

10. A connector assembly as set forth in claim 7, in which each of said first and second side arm portions has formed on its laterally outer edge teeth contacting the inner face of each of said side wall portions of the housing structure.

11. A connector assembly as set forth in claim 4, for use where said printed circuit board has said contacts carried on only one of the surfaces of said edge portion wherein said housing structure has said contact elements carried on the inner face of only one of said side wall portions thereof, said first side arm portion of said retaining member terminating substantially half-way of said elongated groove in said housing structure.

12. A connector assembly as set forth in claim 11, in which said second side arm portion of said retaining member has a laterally inward projection contacting in use, one surface of said contact-carrying edge portion of said printed circuit board.

13. A connector assembly as set forth in claim 12, for use where said printed circuit board has an aperture formed in its contact-carrying edge portion, said inward projection of said second side arm portion being received in said aperture.

14. A connector assembly as set forth in Claim 4, in which said lateral intermediate portion of said retaining member has formed in said upper lateral edge a recess having a width substantially equal to the thickness of the contact-carrying edge portion of said printed circuit board.

15. A connector assembly as set forth in Claim 4, in which said bottom wall portion of the housing structure is formed with a lateral slot and said retaining member further has a longitudinal inter-mediate portion extending from said lateral inter-mediate portion in opposite direction to the first and second side arm portions and closely received in said lateral slot in said bottom wall of the housing structure.

16. A connector assembly as set forth in claim 15, for use where said mother board is formed with a slot located in alignment with said lateral slot in the bottom wall portion of the housing structure, said retaining member further having a catch portion and consisting of a pair of spaced parallel limbs partly received in said slot in the mother board and having lower end portions projecting from the lower end of said mother board and in retaining engagement with the lower face of the mother board.

17. A connector assembly as set forth in claim 16, in which said limbs of the catch portion of said retaining member are respectively formed with laterally outwardly stepped edges in contact with the lower face of said mother board.

18. A connector assembly as set forth in claim 17, in which said laterally outwardly stepped edges extend substantially perpendicularly from said limbs and are in contact with the lower face of said mother board along the entire lengths thereof.

19. A connector assembly as set forth in Claim 17, in which said laterally outwardly stepped edges are inclined laterally outwardly away from said longitudinal intermediate portion of the retaining member and in contact with the edges defining said slot in the mother board.

20. A connector assembly as set forth in Claim 16, in which said limbs of said catch portion of the retaining member are respectively formed with laterally outwardly stepped edges in contact with the outer face of said bottom wall portion of said housing structure.

21. A connector assembly as set forth in Claim 15, in which said longitudinal intermediate portion has formed on its laterally outer edges teeth contacting the surfaces defining said lateral slot ill the bottom wall portion of the housing structure.

22. A connector assembly as set forth in Claim 6, in which said retaining member further has a projection projecting angularly upwardly from one face of at least one of said side arm portions of the retaining member and elastically deformable toward and away from said face of the side wall portion in longitudinal direction of the housing structure and in which said vertical groove formed in that side wall portion of said housing structure which is located close to the side arm portion formed with said projection has a lower enlarged portion having an upper end defined by a stepped wall forming part of the side wall portion, said projection being in engagement with said stepped wall for preventing said retaining member from being moved away from the inner face of said bottom wall portion of the housing structure.

23. A connector assembly as set forth in claim 2, in which said retaining member has a pair of side arm portions respectively in contact with the inner faces of the side wall portions of said housing structure, a pair of intermediate portions located laterally inwardly of said side arm portions and at least partly extending in parallel with the inner faces of the side wall portions of the housing structure and end por-tions projecting downwardly from said mother board and engaging in use, the lower face of the mother board, wherein said printed circuit board has its contact-carrying edge portion received between said intermediate portions.

24. A connector assembly as set forth in claim 23, for use where said printed circuit board is formed with an aperture in its contact-carrying edge portion, wherein said intermediate portions of said retaining member are respectively formed with laterally inward protrusions which are received in said aperture in the printed circuit board.

25. A connector assembly as set forth in claim 23, in which said end portions of said retaining member are laterally outwardly curved and have, in use, their respective tips in contact with the lower face of said mother board.

26. A connector assembly as set forth in claim 25, for use where said mother board is formed with apertures located adjacent the inner faces of said side wall portions of said housing structure, wherein said end portions of said retaining member are partly received, in use, in said apertures, respec-tively, in said mother board.

27. A connector assembly as set forth in claim 23, in which said bottom wall portion of said housing structure is formed with a lateral slot having opposite ends defined by wall surfaces which project laterally inwardly of the housing structure and in which said retaining member further has a pair of snap portions each extending between each of said side arm portions and each of said end portions, said snap portions being received on said wall surfaces defining said lateral slot in the bottom wall portion of the housing structure.

28. A connector assembly as set forth in Claim 23, in which said side wall portions of said housing structure are formed with respective vertical grooves extending between the upper and lower ends of the inner faces of the side wall portions and respectively receiving said side arm portions of said retaining member therein.

29. A connector assembly as set forth in Claim 2, in which said retaining member has a first side arm portion in contact with the inner face of one of said side wall portions of said housing structure and a second side arm portion in contact with one surface of the contact-carrying edge portion of said printed circuit board.

30. A connector assembly as set forth in Claim 29, in which said bottom wall portion of said housing is formed with a lateral slot and said mother board is formed with a slot located below said lateral slot in the bottom wall portion of the housing structure, said retaining member having a first end portion extending from said first side arm portion and passed partly through the lateral slot in the bottom wall portion of the housing structure and partly through the slot in the mother board, said first end portion projecting downwardly from said mother board and in contact with the lower face of the mother board and a second end portion received in a wall surface defining one end of said lateral slot in the bottom wall portion of the housing structure.

31. A connector assembly as set forth in Claim 30, in which said wall surface defining said end of said lateral slot in the bottom wall portion of the housing structure is substantially semi-circularly protruded toward the other end of said lateral slot and in which said second end portion of said retaining member is closely received on the protruded wall surface.

32. A connector assembly as set forth in Claim 30, in which one of said side wall portions of the housing .
structure is formed with a vertical groove joining at its lower end said lateral slot in said bottom wall portion and in which said first side arm portion is received at least partly in said vertical groove.

33. A connector assembly as set forth in Claim 1, in which one of said side wall portions of said housing structure has formed in its top wall a recess open to said elongated groove in the housing structure and said bottom wall of the housing structure is formed with a slot laterally aligned with said recess, wherein said retaining member has an inter-mediate portion in pressing engagement with one surface of the printed circuit board, an upper end portion received in said recess in the side wall portion, and a lower end portion project-ing downwardly from said bottom wall portion of the housing structure through said slot in the bottom wall portion.

34. A connector assembly as set forth in claim 33, for use where said printed circuit board has an aperture formed in the contact-carrying edge portion thereof, wherein said intermediate portion of said retaining member is formed with a laterally outward protrusion which is at least partly received in said aperture in the contact-carrying edge portion of said printed circuit board.

35. A connector assembly as set forth in Claim 1, in which said retaining member is integral with one of said side wall portions of said housing structure for pressing said printed circuit board against the inner face of the other of said side wall portions.

36. A connector assembly as set forth in Claim 35, in which said retaining member comprises an obtusely bifurcated projection on the inner face of said one of the side wall portions of said housing structure, said bifurcated projection consisting of a pair of angularly spaced arm portions extending in vertical direction of said housing structure and in contact with said printed circuit board at their respective free ends.

37. A connector assembly as set forth in Claim 1, in which said retaining member is constructed of an elastic metal wire.

38. A connector assembly as set forth in Claim 1, in which said retaining member is constructed of a substantially flat elastic plate.

39. A collector assembly as set forth in Claim 2, in which said retaining member is formed of an electri-cally conductive material for providing electrical connection between said contacts on said printed circuit board and circuit components on said mother board.