CA1088170A - Zero insertion force printed circuit board edge connector - Google Patents

Abstract

ABSTRACT

A sequentially actuated zero insertion force printed circuit board edge connector has electrical contacts which are sequentially cam actuated for engagement with, and disengagement from, an edge of a printed circuit board. The connector has a housing with an elongate board receiving channel, an elongate stepped contact drive member lying freely at the bottom of the channel and a cam member movable between the drive member and the base of the channel. A plurality of the contacts are mounted in spaced apart relationship along at least one elongate wall of the channel. The contacts have a normal position in which they engage the pads of the printed circuit board and are sequentially moved, in at least two groups, by the drive means to an out of engagement position allowing unhampered insertion and withdrawal of the printed circuit board with respect to the connector.

Description

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~ s ~IIV~ iO~I t-elCl~ C 5 l o ~ 5S Xt~ n o]~ce px:l.n~ed c~:l.rc~ board ed.~f~ conllecl:or.
~c~ord:ln~ tc~ one a~pect o'l khe :lnventiorl/ a zero insertiorl fo.rce pri.nted circu~t board edye connectox, compri.seC an insulating housiny havi.ng a channel therein fo~ receiv:irlg a printed clrcuit boar.d a.lonc3 a boal-d in~ertl.on path, a row of electrlcal contacts positioned heside the channel each having a cc~ntact surface for engaging the prin~ed clrcui~ boa.rd Wh~rl such has been inserted into ~he chann~l, and a cam memher movable to displace a contact driving member normally of the channel to move ~ach contact between a ~oard receiving ~lxst position in which the contact surface of the contact is withdrawn from the koard insertion path and a board engaging second position in which such contact surEace intersects the board insertion pathr the con~act driving member bei.ng formed with ~elatively stepped surfaces succeedln~ one another in the long.itudinal direction of the channel :Eor se~uential enga~ement with the contacts of the ~ow, to move them se~uentiaLLy between thei.r first al~.d second positions, in response to ~he movement of the cam me~ber.
Ac~ording to allotlle.r aspect o the inventi.on, a zero insert.ion orce pxirlted ci.rc~u:Lk boal-d edge , ~ 2 ~

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.in parallel spacetl apart rel..ltion~,lnip e~;:er.lcliny 5 ~lo.nq a-t 1 ea~ :: one~ elonga~:e si.de o~ said apertu.re, a lilce plural.i~y of cort'cact pa~;sa~3ewa~, E; al:7.gned.
W:i th xespectlve :recesses and e:~'cenà:ing throucfh a ka~;e por1:ion of the housiny, anc~ a cam rece:iv:Lng gxoove extending lorlyitudi.nally o~
~o and central.ly in the bottom of the apertl.lre and opening there into; cam mearts mounted for ~otational movement in the groove; a contact dxi.ving member mv~rably mourlted in the elongate aperl:llre of the housing and adapted to be driven ~5 }~y the cam means in a direc_ion normal to the cam recei ving groove, t:he con~act driving Tnember . .
having a longitudinal].y s~epped profile, and a . plurality of electrioa]. contacts each having a resl.Llerl~ ~oard iengaging por~ion and a texminal ~-20 portion formed integrally therewith, ~he con~acts being fi.xedly mowlted in parall~l spaced relatlon along at least one elongate sid~ o the housing apert.ure wl~h the terminal portio~s thereo~ extenAi.ns ~hrough th~ passageways and ~lth tlle board engacJin~ po.rtions thereof positioned so as ~o be e.ngaged by the contact d~ivlnc~ means, whe.rieby scl.id contaots are se~u&ntially ~ 3 -~ !, "~; ' ,: ;'` ;'` ' ' ' ' ' ' , ' .`" '' . . ' " '' ' : , :' '.~ ' ' : . '' . : ' ' ~ . . ~ ! , . ' . ~ : . . .:: . ' ; : , . , . ; . ! ., ' - ' ~: , . . , ' : ,; ' : :
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engaged by the driving means and driven between a first normal position, in which they engage a circuit board positi.oned in the board receiving aperture and a second position in which they are disengaged from the board.
According to another aspect of the present invention, there is provided a zero insertion orce printed circuit board edge connector, com- :
prising an insulating housing having a channel therein for receiving a print-ed circuit board along a board insertion path, a row of electrical contacts positioned on each side of the channel and extending in the longitudinal directions thereo$J each contact having a contact surface for engaging the printed circuit board when such has been inserted into the channel, and con-tact operating means comprising a cam means movable to displace a contact driving means in the direction in which the board insertion path extends, to move each contact between a board receiving first position in which the con-tact surface of the contact is withdrawn from the board insertion path and a board engaging second position in which such contact surface intersects the board insertion path~ the contact operating means being formed with relatively stepped surfaces succeeding one another in the longitudinal direc-tion of the channel so that the contacts are moved sequentially between their first and second p~sitions, in response to the movement of the cam means, the relatively stepped surfaces being provided on the contact driving means and serving sequentially to engage the contacts of the row, the contact driving means being in the form of a single contact driving member which comprises a base from opposite edges of which extend side walls, the stepped surfaces being ormed in the free longitudinal edges of the side walls, so ~that the height of each side wall increases in one longitudinal direction of the channel.
For a better understanding of the invention reference will now be made by way o example to the accompanying drawings, in which:-~ ' ~ ~ ,'.
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Figure 1 is a perspective view o:f a sequentially actuable zero insertion force printed circuit board edge connector which embodies the invention, the connector being shown in a board engaging condition;
Figure 2 is a longitudinal vertical section through the connec~or of Figure l;
Figure 3 is a top plan view of the connector shown partly in horizon~al section, the connector being shown in an intermediate condition;
Figure 4 is a transverse vertical section through the connector with contacts thereof in a closed, position;
Figure 5 is a partial transverse vertical section, through the connector with the contacts in an open, board receiving position; and Figure 6 is a foreshortened perspective view of a contact driving member of the connector.
The connector comprises four primary components, namely, an elongate insulating housing 12, a cam :

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me~nber 1~1, a cc)rltar.~t drivlng In~mbex :L6, and c-A
pl.uralit~ o spring el.2ctri~al contact:, 18~
The housing 12 has moun~i.ng flanges 20 and 22 a~ the opposi~.e ends thereo~ or secur:ing the conn~ctor to a mother prl.llted cixcuit ~o.lrd ~4 by means o~
fa.stenexs 26 (Figure 2)~ The housing 12 has . formed therein an ~longa~e celltral guide channel 28 for receiving a daughter circu.i.t board 30, ~he longitudinal side walls 2 of the housing 12 belng lQ formed w.ith spaced .rlbs 22 projecting inwardly from : the side walls 2 and defining recesse~. 34. Each recess 34, which commu.nicates with the channel 28, receives a respective contact 18. A passage 36 extend~ from the lower (as seen in Figure 4) end : 15 of each recess 34 through a base 38 of the housing 12. The base o~ the channel 2~ is formed with a central lonqitudinal yroove 43 which comrnunicates t:L~h a slor. 41 in one end o~ the housing 12 and with an opening 39 in the other end thereof, opposed xecesses 42 being formed in ~he uppe.r (as seen in Fiyure 1) portions of the side walls of the slot 41 and opening into the upper surfae of the housin~
12.
; :The contact drivlng m~mber 16, which lles i~ the channel 28 ls, as best seen in Figure 6, channel ~;~haped, havin~ a ~ase 44 and parallel side walls 46 and 48, the ~ree longitudlnal edyes of the .side ~all.s 46 and :- _ 5 -;

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4 ~ h~ c)~ e(l~ ac; ~."~-,J~ .i.r~ r~ 6, wiil 5tep~ 49 se that thri helgl-l~ o', t:he r:ree long:L~Ild:i.n.
~dges o~ these s~l~de wal.ls :i.ncrease~r-; ~om .r~ ht to left, as s~en in Fiyures 2 alld 60 These ~ree longitudiQal edt3es ha~e cham:Eered ou~er ~aces 47 cons~citut-ing at leaLst two xela~ively stepped surfaces succ~ed.ing on~ another ln the longitudlnal di.rection of the channe:L 28. The end.s o the base ~4 have hevel.led .suraces $0 and 52. ~s shown i.n `~
Figures 2~ 4 and 5, the outer or lower surface of the base ~4 faces the mouth of the groove ~0.
The cam memb~r 14 compri.ses an elongate cam portion 60 and a res.ilient, loop-shaped, handle 62.
The cam portioll 6~t which is slidahl~ and ro~atably received in the groove 40, is shaped, as seen in cross-sectlon (Figures 4 and 5), as an elongats quadrilat~ral having parallel sides joined by radli.
The handle 62, which has a ~ree end portion 64, extends from the cam portion 60 externally of the housin~
2C) 12, or rotating the cam portion 60 about its longi.tudinal axis and for sl.iding the carn portion 60 lon~itudinally of the groove 40. .
T~le con.tacts I8 may he 0rm2d Ior example by s~amping and forming metal strips, or by rolling ana forming ~ire D ~ach contact 1~ has a resilient~
inwardly bowed, hoard engayins, con~act surface 54 -~ 6 , . : : - , . :
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~ c~ o~ti.~n 5~ w~ tl~, 'C~lrOII~ On{' 0~ pd';E;~S 36 ~0:.' ITIC~ lr~ ,c~ 1. clJl~! t~ (,t:~lc~
conilec i:.:l.on to a pr:i..n'ccd corlduci:or 5~ i':~ gurl3 ;~ ) on the inother boaxd 24 and to further condu.ctors ~no'c sho~,7n) and thus t.o elec..rical clrcui.ts inot show~l) by ~7:Lre wrap conneccioils ~not shown), for: ~xarllpleO Each cont~ct 18 is, re'cained agains~. withdrawal. from the hous:Lng by mearls, or exampl.e; of a locking lance (not ~hown) or by the flc~w of the houslng materlal during LO mantlfac~ttre of the conllector, lnto an aperttlre (not shown) ln the contac~ 18.
The free end por~ion 6~ of the h~ndle 62 .is xeceivable i.n the recesses 42 of the housing, for the avoidance unlntended rotatlon o, and removal, in the dlrection of the arxow B in i~igure 1, from ~he connector of, the cam member 14.
; The connector is assembled by inserting tlle carn porti.on 60 of the memhex 14 into the groc~ve 40 and the contact driving member 16 lnto the chan~el 2~, ald~d by ~0 ~h~ be~elled sur~ac~s S0 ox 52.
: When the cam portion fiO is positioned as ShGW~
Ll~ Figures 1, 2 and 4 so tha~ it5 broader s:ides 61 l.ie parallel to the base of the groove ~ and to the base ~-~4 o~ the driving memb2r 16, the drlvlng member 1~ ta]ces up a retxa~ed po~.itlon so that all the surfaces 54 c:~
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the cont~ct~ l& are in a board eng~glng position, in whlch they pro}e~t into the lrlsertion path o the : - 7 ~
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r~r~ .3 ~c~rl(~ d :Irl 1:.}~ d~ c'c.; c o:E ~he a.r^rG~ i.n ~ Jw~e 3, tlle cam portlcJn 60 ls Æotat.ed about i~:~; lon~ltl;a~.lal a~:Ls ~owards the~
5 pos:i t:i.on of :~'.iyure 5 i.n wh.ich t;he broader sides 61 of the portiorl 6(: ex'cend no.rmaï:Ly of the base o:f the groove 40 a.nd of '~he ou~.er .~urface o the bas,e 4~ ~
Durin~ such r~taki.on. of t:hc handle 62, 10 the drivir.~ meml)er 16 is pro~re~;sively forced by the cam porti.on 6Q Ln a direction normal to khe base of t~he groove 40 ~nd thus of the hase of the channe] 28, and away ther~from, so that the cha~fered faces 47 of the fr~e lon~itudinal edges of the side walls 46 and 48 of the driving member 16 se~uenti.ally enyage respective ~Jroups of th~ contacts 18 to mo~e th.e con~act surfaces 54 thereof ou~wardly lnto the recesses ~4 and thus illtO theix hoard reeelving positlons shown in Figure 5, in whic~l ~he ~0 con~.act surfa~es 54 are withdxaw~ from the ; ins~.rtion pa~h of the ~oard 30~ ~s shown in Fiyur~
3 t the let~ard group of contact surfaces, 54a, are f.irst dri~e~ into their board rec~iviny positions ;~ ollowed ~y th~ next adjacent group of contac~
suxEaces, 54b, and so on ln predetermilled sequenc~.
When all the groups of contact surfaces 54 have thus heen moved into thelr board recelving .~.

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the ~hannel 2~ alld ~he handle ~,2 is rot.lted ~ack to iks posiki.on of Fi~urf~ 1~ to rrlove kh~ grollp~ of sura.cec; 54 seqtlen~lc~ back into the.i.r hoard erlcJag:lny poCitionsO The handle 6~ ~.s the~n pushed xigh~tJardly, i.e~ :l.n ~h.e oppos:lte di~ect:i.on ko that of ~he arro~ owarc~.s l~s po.si~ n of F:i.yure Z and thQ free encl por~ion 6~ of the handle 62 i5 resil.~.ently introduced ln ~he recesses 42 so ~..ha~ the colltact sur~aC'es 5~ are secured ln thel.r engagement with the daughter board 30. The dauyhter hoarcd 2~0 can be ~ubsequently released from the connec~or by again - -xotating the handle 62 in the direction indlcated by the arrc>w A, after removing the free end portlon 64 OL
the handle 62 from the recess~s 42 and withdrawillcJ the handle 62 in the direction of the axrow B in Fi.gure 1.
The ~3rot.lps of ~ontacts 18 axe thereby released ~equentlally .50 that dalnage to the circlllts to wh.; cn the contacts 18 are con3lected and which might axise if the conkacts 18 were simulkaneously disoonn~cted frcJr(- the ; : conduc~ors of ~he boaxd 30, can be avoided.
; There are many cases in which it is either desirable or necessaxy, or both, for power, ground and signal circuits to be broken seque~ntially, for mechani.cal or elec~rlcal reasc)ns~ For e~ample, ~. . . .
: ~there hl-polar logic devices, whlch have both po.~.itive and negatlve power supplies are employed, ;:~

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1.at~.e~ b~ rr Y:~:E~-e~lC~C1 t:O ~37. 0~1r,~1 r '! m;ly ~CC'U~
il~ the (7rOUIld CirCUi.t iS f:ir5t brQke21/ i~.hai: !3uprJly VO1t:ageS ~i11 "at3d~' aCrO~;'; an 1ndi.v:idllal g~lte eïeinent and so des~:roy ~. In diyi.~al ele~ctron:lc .~ystems, or exclmple~ the genera~ion, by remova1 o the daughter board, o~ spurious trans:Lents leading ko da~a ~a1si~ica~10n can be avoided by arrangi.n~
~or the power clrcuit ~.o be first broken.
T~ conn~ctor ~ay have but a sin~le~ row of con~acts 18 for engaging printed conductors on only one side of a daugh~er board, in which case : only one side wa11 o the contact drivlng member need be stepped.
The term printed circuit board is us~d herei.n in its most genera1 aspect and is intended to include any circuit boards, cards or substra~es on which e1ectrica1 conductors have been provided by pri.nting or by any othar suitab]e means.

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Claims (8)

The embodiments of the invention in which an exclusive property or privilege is claimed are as follows:-

1. A zero insertion force printed circuit board edge connector, comprising an insulating housing having a channel therein for receiving a printed circuit board along a board insertion path, a row of electrical contacts positioned beside the channel each having a contact surface for engaging the printed circuit board when such has been inserted into the channel, and a cam member movable to displace a contact driving member normally of the channel to move each contact between a board receiving first position in which the contact surface of the contact is withdrawn from the board insertion path and a board engaging second position in which such contact surface intersects the board insertion path, the contact driving member being formed with relatively stepped surfaces succeeding one another in the longitudinal direction of the channel for sequential engagement with the contacts of the row, to move them sequentially between their first and second positions, in response to the movement of the cam member.

2. A connector according to Claim 1, in which each stepped surface is dimensioned to engage a group of the contacts simultaneously.

3. A connector according to Claim 1 or 2, in which the contact driving member is channel shaped, comprising a base from opposite edges of which extend side walls, the stepped surfaces being formed in at least one of the side walls.

4. A connector according to claim 1, in which the cam member has a handle which extends exteriorly of the housing and is insertable in a recess therein, to secure the cam member to the housing and to restrain rotation of the cam member relative to the housing, when the contacts are in their second position.

5. A connector according to Claim 4, in which the cam member is slidable in the longitudinal direction of the channel to move the handle towards and away from the housing.

6. A connector according to Claim 1 or 2, in which the cam member has a handle which extends exteriorly of the housing and by means of which the cam member can be rotated relative to the housing, the handle having a free end portion which can be moved relative to the housing to allow the free end portion of the handle to be lodged in a recess in the housing.

7. A zero insertion force printed circuit board edge connector comprising; a housing having an elongate printed circuit board receiving aperture, a plurality of electrical contact receiving recesses in parallel spaced apart relationship extending along at least one elongate side of said aperture, a like plurality of contact passageways aligned with respective recesses and extending through a base portion of the housing, and a cam receiving groove extending longitudinally of and centrally in the bottom of the aperture and opening there into; cam means mounted for rotational movement in the groove;
a contact driving member movably mounted in the elongate aperture of the housing and adapted to be driven by the cam means in a direction normal to the cam receiving groove, the contact driving member having a longitudinally stepped profile;
and a plurality of electrical contacts each having a resilient board engaging portion and a terminal portion formed integrally therewith, the contacts being fixedly mounted in parallel spaced relation along at least one elongate side of the housing aperture with the terminal portions thereof extending through the passageways and with the board engaging portions thereof positioned so as to engaged by the contact driving means, whereby said contacts are sequentially engaged by the driving means and driven between a first normal position, in which they engage a circuit board positioned in the board receiving aperture and a second position in which they are disengaged from the board.

8. A zero insertion force printed circuit board edge connector, comprising an insulating housing having a channel therein for receiving a printed circuit board along a board insertion path, a row of electrical contacts positioned on each side of the channel and extending in the longitudinal directions thereof, each contact having a contact surface for engaging the printed circuit board when such has been inserted into the channel, and contact operating means comprising a cam means movable to displace a contact driving means in the direction in which the board insertion path extends, to move each contact between a board receiving first position in which the contact surface of the contact is withdrawn from the board insertion path and a board engaging second position in which such contact surface intersects the board insertion path, the contact operating means being formed with relatively stepped surfaces succeeding one another in the longitudinal direction of the channel so that the contacts are moved sequentially between their first and second positions, in response to the movement of the cam means, the relatively stepped surfaces being provided on the contact driving means and serving sequentially to engage the contacts of the row, the contact driving means being in the form of a single contact driving member which comprises a base from opposite edges of which extend side walls, the stepped surfaces being formed in the free longitudinal edges of the side walls, so that the height of each side wall increases in one longitudinal direction of the channel.