CA2145930C

CA2145930C - Push-fit connector for joining two fluid lines

Info

Publication number: CA2145930C
Application number: CA002145930A
Authority: CA
Inventors: Christoph Steinkamp; Bernd Kleinhens
Original assignee: Rasmussen GmbH
Current assignee: Norma Germany GmbH
Priority date: 1994-04-18
Filing date: 1995-03-30
Publication date: 1999-06-15
Anticipated expiration: 2015-03-30
Also published as: FR2718822A1; DE4413346C1; FR2718822B1; ITTO950288A0; GB2288646B; JP2616743B2; CN1047834C; GB9507754D0; GB2288646A; IT1280864B1; CA2145930A1; AU680110B2; JPH07293771A; CN1118853A; US5511827A; ITTO950288A1; AU1641395A; KR0162154B1; KR950029654A

Abstract

A push-fit connector for joining two fluid lines (1, 4), one of which is provided with a retaining rib (2), has a sleeve (5) with radial apertures (12, 13), a latching device (6) with retaining arms (18), which can be pushed into the sleeve (5), provided with hooks (20) for gripping behind the retaining rib (2) and a radially external inclined surface (21). When the sleeve (5) and latching device (6) move apart, the inclined surfaces (21) are compressed against a front edge of an aperture (12) receiving the hook (20) in an axially displaceable manner, so that She hook (20) stays correspondingly more tightly engaged with the retaining rib (2) When the latching device (6) and the inserted fluid line (1) are pulled apart, a radially internal inclined surface (23) of the hook comes into contact with the retaining rib (2) so that the retaining arms (18) are spread apart and make uncoupling possible. In order to facilitate uncoupling, the latching device (6) has an unlatching arm (19) between at least one pair of adjacent retaining arms (18), which arm projects outwards through the aperture (13) in an axially displaceable manner.

Description

21~5930 RAS~USSEN GMBH

Push-fit connec~or for joinin3 t~o fl~id lines 5 The inYention relates to a push-fit conn~ctor for joining two fluid llr~s, on~ of which is provided wilh a~ least one ,~ ,i"y rib, ~he conneclor comprisin~ a sleeve provded with radial ap~rtures; a cylind~ al latching de-~ice which is axially moveable in the sleeve and provided with axially exter~ and elastically ~exit~le retaining arms each having a hook c~nfigured on its free 10 end for grasping behind the retaining rib of s~id one ~uid lins ins~,t~l axially into the latching devlce, wl~erein the hooks are provided on their free en~s with a radially external incl;n~ surface which, when the sleeve and la~hin~
de~ice are moved in a ~lir~c~ion apart from one another, is ~r~ss~ a~ains~ a front ~dge of an aperture in the sleeve, which ape~ture reoeives the radially 15 Bxternal patt of the hook in an a~tially II spl~~e~le manner~ so th~ the hooke~"c~n,ed stays cones,con~lingly more bgh~ly enga~l with the retaining rib, and providexd with 2 Radially inte m alinclinet~ sur~c~s whieh cx~mes into C~Dntaet with the retauning nb when the latehing d~vic~ anK~ ins~ l fluid line an3 pulletd in a direction apart from one another, so that the reta~ning ~rms ar~ spread 20 apar~ and allow uneoupling; and at least one sealiny ring between an inner shoulder of the sl~eve and the latehing deviee.

In a known push-fit conneetor of this fype (EP 465 896 B1), the latehing deviee has, on its axially ~xter"~l end, a ~lange ~uroj~.~,~ radially ouh~ards Z5 and onto whieh the I~S~hin~ device must be taken hold of manually and pushed axially inwards into the sleeve in order to b~ able to pull out and uneouple one fluid line ~rom the latehing deYiee while there is radial s~,re~ingof the retaining arms. This rneans th~t the p~sh-fit connector must be accessi~lQ axially from the fron~ In many cases ~his is not the cas~, I,ow_~cr, 3~ for eAam~ in the case where the fluid line inserted in the latching d~vice i8a pipe soclcet which is mouldsd onto a ho~sing, for eAalllpl the housing of .. .

- 2 ~ 4 ~ ~ ~ O

a motor vehicle radiator. In this case the distance between the push-fit connector and the housing is often too small for the flange of the latching device to be comfortably taken hold of manually. It would be too expensive in terms of materials to configure the pipe sockets longer and the retaining ribs at a greater distance from the radiator housing.

The object of the invention is to provide a push-fit connector of the type described in the introduction which allows easier uncoupling of the fluid line inserted in the push-fit connector even in cases where the push-fit connector is not accessible from the insertion side.

The invention provides push-fit connector for joining two fluid lines, one of which is provided with a retaining rib, comprising: a sleeve having a central opening to receive the one fluid line with retaining rib, said sleeve having a plurality of apertures spaced around its circumference; a latching device within said sleeve having a main body with at least one abutting surface cooperating with a surface within said sleeve to permit limited movement of said latching device within said sleeve along the sleeve longitudinal axis, said latching device having a pair of elastically flexible retaining arms spaced apart on and extending from said main body generally axially of the sleeve, each said retaining arm having a hook on its free end projecting toward said sleeve longitudinal axis for grasping behind the retaining rib of the one fluid line inserted axially into the latching device ... , ~ .. ., .. , . . . . . , . ~

~ ~ 4 ~ o between said retaining arms to couple said latching device to the one fluid line, the inner surface of the free end of a hook having an inclined surface which, when said sleeve and said latching device and the one fluid line are moved toward each other, moves over the retaining rib of the one fluid line to spread the retaining arms apart to permit the hook to latch over the retaining rib, each hook also having an external part disposed in a respective aperture that is axially movable of the sleeve within the respective aperture, the front edge of the free end of a said hook having an outer surface inclined toward the sleeve axis which, when the one fluid line moves apart from the sleeve and retaining device, said hook becomes correspondingly more tightly engaged with the retaining rib by said hook front edge inclined outer surface within its respective aperture engaging the sleeve at a first edge of the respective aperture closest to said central opening, each hook also having an internal inclined surface which contacts the retaining rib when the latching device and inserted one fluid line are moved apart from one another to move the retaining arms radially outward of the one fluid line retaining rib and spread the retaining arms apart to allow uncoupling of the one fluid line from said latching device; and at least one unlatching arm extending generally axially of said sleeve from said latching device body between at least one pair of adjacent retaining arms and having an actuating part projecting outward through a respective one of said apertures to be engaged to move said locking device axially away from said sleeve central opening to uncouple the hooks of the - 2b -retaining arms from the retaining rib of the one fluid line as the one fluid line is moved away from said locking device.

The invention also provides a push-fit connector for interconnecting two fluid lines, one of the fluid lines having at least one external peripheral rib provided thereon, the connector being fittable to the other of the fluid lines and being capable of releasably retaining the one fluid line therewithin, the connector comprising: a hollow sleeve having a plurality of apertures around its circumference; a cylindrical latching device receivable and longitudinally movable within the hollow sleeve, the latching device comprising radially flexible elastic retaining arms each having a hook formed in a free end thereof, each hook being capable of engaging with the rib to secure the one fluid line within the connector, the hooks each having a radially outwardly extending projection loosely locatable within a respective one of the plurality of apertures to retain the latching device within the hollow sleeve and inwardly inclined internal and external surfaces for abutment with the rib and an edge of each aperture, respectively; at least one sealing ring provided between an inner shoulder of the sleeve and the latching device; and at least one unlatching arm each locatable at least partly within one of said plurality of apertures and operable to allow separation of the one fluid line from the connector; wherein, in use, movement to separate the one fluid line from the connector without operation of the unlatching arm causes the latching device to move such that - 2c - z ~ 3 ~

each external inclined surface bears upon the edge of the respective aperture thereby more tightly to engage each hook with the rib; whereas movement to separate the one fluid line from the connector whilst operating the unlatching arm restrains movement of the latching device and causes the rib to bear upon each internal inclined surface thereby to axially move each hook out of engagement with the rib to allow separation of the one fluid line from the connector.

It is possible by means of the unlatching arm to press the latching device axially further inside the sleeve for the purpose of uncoupling the inserted fluid line, even when the sleeve is at only a small distance or even no distance at all from another object.

The latching device can also be provided with a ring on which the retaining and unlatching arms are moulded axially. This configuration saves material and makes possible complete insertion of the latching device in the sleeve without the latching device projecting axially out of the sleeve. A pipe socket forming the fluid line can therefore be configured shorter as the sleeve and the latching device can be pushed onto the pipe socket as far as the end opposite the insertion end.

It is also advantageous when at least one of the retaining and unlatching arms is provided with a radial contact surface for contacting a rear edge of the 21~930 aperture in order to limlt the insertion of the lalchiny devic~. This in~e,bon lirnit n~t ~nly ensures that durin3 ass~",~ the latching device is brought into the correct position but also that during insertion of on~ o~ the fluid lines into the latching device the sealing rin3 is not C~l"p essedi by the dis~l~cement of She 5 la~ching devic~ in the sleeve ther~by efF~cl. Moreo~er there is no need for an a~ial retaining ring fot the sealing ring lue~ n the sealing ring and the latching devioe.

It is further ~ref~rdlJly ensured that the hooks f~r receiving the ret~n;ng rib ar~
10 provided on their radially internal sides with a recsss which is delimiteci on its axially external inner side by the radially intemal inclined surface of cu~ed shape and on its axially inlerna~ inner side by a radial sur~ nd dimensioned that th~ recess receiYes the retalnlng rib regardless of the toler~nces of its axial width, without any clearance.
In the area of the apeture r~ceiv;ng it each untatchin~ arrn can p~ject beyond the circularly cylindrical periphe~y of the sleeve. It is Iher~f~r~ easy to take hold of manually and can ~e d;spl~ togeth~r with the lalch;n~ device for the purpose of uncoupling the ir,s~n~ fluid line.
It is also possible ~vJ~C er for the sleeve to be provid~d with a Raller,~l areaextending transversely with respect to the longitudinaJ axis of th~ slee~e on both sides of each apertur~ receiving an unlatchin~ arrn ar~ the ullldtchin~
arm exte"~i"~ through ~is aperture sxlen~l~ beyond this ~lall~n~ area at the 25 most up to that one of two cylindrical sl~vc(s) surfaces o~ ~liFfbr~,lt (li~."et~,~
on both axially ~ ent sides of the aperture which surface has the smaller diameter and thal an axial inl~""~lia~e space exists beh~een the pa~ of the unlatching arrn projec~n~ out of the sperture and the s~rface of the sleev~
with the larger diameter for inserting an unld~ y tool. In this configura~on 30 the ~ ~ nen~ of ~e latching devic~ can also ~e e~fected by means of a t~l for exan~p~e afork v~ nch.

9 ~ 0 When two unlatching arms ~ "etnc~ly ~I~posile one an~tl,er with respect to the longitudinal axis cf the sleeve are provided, they can be simultaneous~y displaced with one hand or, for example, with a fork wrench for uncouplin3.
In addition two retaining arms to a large extent counteract radial ~;spl~,ement 5 o~ the push-fit conn~-~ur when a radial force is exerted on the pushfi~
connector.

~he unlatching arms can ~e elastically flexible and be ~lo~ ~l with a partly cylindrical int~rnal surface for fixing onto the radial e~t~",al ed~e of the 10 retaining rib, which ",~,g~s ~o~a~s the fres snd ~f th~ unlatching arm into an inclined surface. This configuration of the unlatching arms also contr~butes to the prevention of radial displacement of the push-fit oonnector and thereby effects guidance of the fluid line inser~ed in the lalo~ device. The inclined sur~ace on the free end of the unlatching arms thereby hc;'it~tes the insertion 15 of the fluid line into the lat~l,ing devlce.

The hooks can be provided with latera pruj~ ions for fitting into the inte~or of the sleeve. This configuration increases the resi~nce of the retaining arms to a la~eral displa~e",e,t~ of th~ push-fit connector.
Each unlatchin3 arm can also be providsd with a radially e~f~ lc1;n~3 surface on the free end. It is then also pressed radialty Ir.,~ irlsl the l~taill;llg rib, when the fiuid line inserled in the lat~l-iny devioe is presseda~ally outwards becaus~ of th~ internal pressure of the pipeline. The ,~aining 25 arms then also con~rib"~e to the axial retenlion of th~ ir~s~l~l fluid line.

The invention and its h~rther developments will now be descnbed in more detail with th~ aid of the drawings of preferred ei"l~iments. In these is shown in:
Fig. 1 an axi~ section of a push-fit ~onnector aocording to the invention ., . ~ .. . ~ . . .. . .... . .. . .

21~.5g30 with a fluid line to be inserted into the push-fit connector in the forrn o~ a pip~ socket with a retaining rib and a fluid line pushed onto and firmly clamped onto the oFipo5il~ ~nd of the push-fit connector, 5 Fig. 2 a front Yiew of She push-fit connect~.r ac~ in~ to Fig. 1, Fig. 3 a side view cf the push-fit oonneclor ac~ to hg. 1, Fig. 4 a side view of the push-fit connector ~o~or~ir,g to Flg. 1 in a posi~ion rotated by 90~ a~out its longitudinal axis with r~sp6~1 to the push fit connector acco~ing to tig. 3, ~ig. 5 an axial section through a sleeve of the push-fit cGnn~tor, 15 Flg. 6 a s~cbon Vl-VI of Fig. 5, Fig. 7 a side view of th~ sleeve aocording to Fig~ 5, Fig. 8 a side Yiew of the sleeve in a position rota~ed by 90~ about its lon3it~dinal axis with r~sp~cl to the position aco~ i"y to Fig. 7, Fig. 9 the s~ction IX-IX of the Idt~;hiny devic~ of the pushht c~nn&c~ot accord;ng to the invention, 25 Fig. 10 a side view of the latchi~g device, Fig. 11 a front vie~ of the latching dsvioe, Fig. 12 the sect;on XII-X~I of Fi~. 11, Fig. 13 a side view of the l~hin~ devioe in the position of the an~le of 21459~0 rotation accord;ng to Fis. 12, Fig. 14 a modification of the push-fit connector according to ~hs ;nvention, ~ Fig. 15 to 18, .Jill~r~,d phases in the us~ o~ pUSh-fit col~nec~or acc~ to the invention ~or ex~.~inir,y i~ "~tho~ of ~.~on, and Fig. l 9 to 21, different IndiYidual ~ r~sen~tions of a r~t~ning arm o~ the push-fit wupling ~ r~ing to the invention ;n oo~p~r~tion wi~h a reWning rib ~f a fluid line tn bs co~pled, the rib having differenS
~ndths or di,l,ensional toler~nc~s.

The push-fit oonnector ac~ ing to Fi~s. 1 to 4 serves to join a fluid line 1 in ~5 the form of a pipe socke~ which Ts proYTded with a continuous QxlQn)ai retaining fib Z and is mouWed onto the housing 3 of a motor vehicle ts~ lor, to a fluid line 4 in the forrn of a hose made of pl~ics. The push-fit connect~r is c~",pose~ of a ~;~rlin.~,cal sleeve 5, a lat~ing devic~ 6, tw~ sealing rings 7 and 8 in the form of O nngs with a re~sining ring 9 ~,~ng~J between them, 20 and a tensiona~le hose band clip 10, clamping sleeve or sirr~lar clarnp whichis fixed around th~ hose 4 and clamps it firrn~ to a ribbed end 56C~;GIl 11 of the sleeve 5.

Ths o~her end section of the sleeve ~ has hur radial aperh~res 12 and 13 in 25 the form of reo~r,yles r~gularly distribu~d about its ,~r,~l,ery, which extend in the longitudinal direcn'on of ~he sleeve 5. The end section of the sleeve 5 provided with the aper~res 12, 13 has a lar~er ~Ji~"eter than the ~ja~enl section of the sleeve ~ which receives the rings 7, 8 and 9, while the section of the sleeve 5 ~ ~nl to the end section 11 is proYided with an intemal 3~ ~ia",~r which is approxi",ately ~he same as the extemal ~ia",eler of the nuidline 1, and the internal ~i~"~t~r of the end sec~ion 11 is equal to the in~ernaJ

2 ~ 3 ~

diameter ~f the fluid line 1. As shown more clearly in Flgs. 3, 4 and 6 to 8, ~he sleeve 5 has externally on both sides of each ape~ure 13 a ~Idllen~3 area 14 exlen~ing transversely with respect ~o the lon3i~dinal axis of the sleeve. On both sides of the ape~tures 1 Z, 13 the sleeve 5 has cylindrical surSaces 15 and5 16 with cli~er~llt diameters, wherein ~he surFace 16 ~ l to the end of the sleev~ 5 has a larg~r dia",eter than the sur~ace 15.

As shown in par~icular in Figs. 9 to 13, the la~ching devio~ 6 is c~ d of a closed ring 17 and two el~sti~lly flexible rstaining arms 18 mouded onto 10 it, as well as two elas~cally flexible unlatching arrns 19 moulded on~o ,t. Th~
retaining arms 18 each h~ve on their Sree ends a hook 20 for yr~yin~ behind the retaining rib 20 when the flllid line 1 is inserl~ axially into the latchingdevice 6. The hooks 20 hav~ on their free ends a ~ially outer inclin~l surface 21 and on their radially inner side a recess 22 which is d~limited 15 on i~s axially e~te-"al inner side ~y a radially inner inclined surfac~ 23 ofcu~ed sha~ an~ on i~s axially internal inner side by a radial surface 24, and dill~ens;on~l such tha~ i~ can recen~e the retaining ~b 2, r~gardless of the ~ol~rar,ces in the axial width o~ the re~ ,y rib, wlthout any ciearance.
Fu~ "l,~re, each hook 20 has a radially inner inclined surface 25 ~ s 20 to its free end and a radial contact surface 26 opposit~ to the axial front end for contacting a rear edge of the r~spective aperture 12 for limitir~ the insertion of the l~t~hir3 device 6. lastly, each r~tainiri~ ar n at the front end of the hook 20 is provided with a lateral projection 27 for contacting the inside of the sle~ve 5. The radially internal surface Z8 of each retainlng arm 18 is 25 partly cylindricsl and has adiameter con~spo~ing to the dia",ctcr of the fluid line 1.

The L.nla~cl,iriy arms 19 lie between the retaining srms 18, wherein the retaining arms 18 and the unl~l,ing arrns 19 are distributed about the 30 periphery o~ the suhst~ltia~ cylindncal l~chii~y de~ice 6 at the same angular spacing apart, so that the two retainlng arms 18 and its hooks 20 are , diame2rica11y opposile w;th respect to th~ longitudinal a~is of the sleeve 5 or of the la~hing de~ice 6 in the same way as the unlatching arms 19. While radially extemal pans of the hooks 20 project into Uhe apertures 12 of the sleeve 5 ar~ are axiall)~ ~ispl~ hle in the apertures, a~ial e~ter"~l parts 29 5 of the unlatcl ,i,~ arms 19 project into and outwar~ly through the ape tur~s 13 (see in par~icular Fig. 4). The r~dial extemal par~ 29 of the unlatoh;r~ arms 19 ar~ additionally each p~ d with a pr~jecti~n S~ pro~ctng radially outwards, beyond the cylir,~lhal surface 15, whiie the ext~or of th~ radial external part Z9 lies ~n a elrcumcirele the diameter of whieh is smaller than 10 ~hat of the surfaee 15. The radially e~l~,n~ 29 and the projecbons 30 are also axially ~ eAI~le wi~hin the ap~rtures 13 which .~c~ive them. As w;th the hooks 20, ~he radially extemal parts 29 and ths 1~r~ GII5 3~ have a radial eontael surface 31 h~ con~ac~in~ a rear ed~e of the apelture 13 f~r limiting ~e insertion of the la~ehing deviee 6. The unlatching anns 19 ar~ aiso 15 el~s~i~y flex;ble ar~ have a partly cylindrica intemal surfaoe 32 fw contac~n~ ~he radially extemal edge of the ~ning rib 2, which m~r~es to~s the free end of ~he ~,nla~ching ann 19 into an ir,cl;n~ surface 33. In the sarne way each unlatch;n3 arm 19 has on its free end a radially ex~emal incl;n~l sur~ace 34.
The push fit con"~c~r acc~r~ to Fig. 14 differs from that accGr~3:n~ to hgs.
1 to 13 only in that the prolec~on 30a is 51 ,o,ter than the projecbon 30, so that i~ does not project beyond the surface 15.

Z5 HereinaRer the Ineti)od of operation of the pushfit connec~r accGr~ling to Figs. 1 to 13 ~rili be descril~l in more detail wi~h the aid of ~igs. 15 to 18.

In order to join the fluid lines 1 and 4, the push-fit col~neclor with the fluid line 4 co"r~ ~ acw-~ir,y to Fig. 1 is pushed onto the fluid line 1, 30 wh~rein the retaining nb 2 presses a~i"sl the inclined surfaoes 25 of the hooks 20 and on the one hand Sp7~:dJ~ the reta~nin~ arms 18 radially 21459~

outwards and on the other hand the entirs latching device 6 is pushed o~lt of ~he p~sition according t~ ~ig. 1 furth~r into the sleeve 5, until the contact surfaces 26 and 31 of the re~ininy arms 18 or unlatchin3 arms 19 lie on the rear edge of the apertures 12 or 13, as shown in Flg. 15. In this position the sealins nngs 7, 8 are en~l~se~l between an intemal shouWer 35 of the sleeve 5 and the latching device 6, without c~""Jressing the sealing ringS 7, 8.

By means of further ~,r~ssing together of the push fit c~"ri~ch,r and the ~uid line 1, the retaining arrns ~8 at last gnp beyond the retaining rib 2 by means 10 of the hooks 20, as because of their tension obtained by the s~r~ng in th~
position according to Fig. 15, they spring back into the position ~coo~ing to Fig. 16. In the position according to hg. 16 the fluid line 1 and the hose 4 arejoined tightly to one anotl~er, wherein the nuid line 1 is guided on its sides at several points and radially supported: on the one hand in the sleeve 5 and on 15 the other hand by means of the ting 17 o~ the l~t~hin~ device 6 as well as bym eans of the retaining arm s 20 and the unlatchin~ arm s 1 9. The unlalchin~
arm s 19 effect the sup~Po~ing in the~ their Fxa~y cyl;r,~icial inte m al surh~ces 32 also fit onto the e~l~rl,dl periphery of the retaining nb 2. The conn~ction ~l ler~f~re als~ Y,/i~,~r,.ls high ~e~J ees of radial forces ~nthout radial deflection 20 of the push-fit conn~clor ~ to the fluid line 1.

When a hi3h pressure builds up in the fluid lines 1 and 4 in the position accor~ling to Fig. 16, its axial cornponen~s affect the sleeve 5 and the fluid ITne 1 so that they are pulled apart a~(ially. ~lowever, with this the inclined surfaces 25 21 of the ret~ning arms 18 and the inclined surfaces 34 of the unlatching arms 19 collide with the fron~ internal edge of the apertures 12 and 13 respectively so that the hooks 20 and the front end sec~ion of the unla~ching arms 19 are press~l ev~n more tightly against th~ r~ ,g rib 2, as is shown in Fig. 1 7. In onder to se~hllc~ the c~nne~ion t~ een the fluid lines 1 and 30 ~, the projec~ons 30 of ths unlatching arrns ~9 projecting beyond the periphe~ of ~he surface 15 a~ ing to Fig. 4 can be taken hold of manually .. , ... , .. . . . ~ , . . . ..

21 459~o and then the latchin~ deYice 6 can be pushed back again into the position accorcling to Fig. ~6. While the projections 3~ remain tightly held, the entire push fit connector ~an then be pulled out of the fluid line 1 and the retaining arms 18 spr~ad out according to Fig. 18.

The uncoupling can also ~e e~F~cLe~ using a co,nmon tooi, for example a fork wrench, which Is inserted b~sn the projec~ons 30 (Fig. 4) and th~ front flan3e of the slee~fe 5 transversely to the longibJdinal direction of the sleeve5, and press~d rearwards a~ainst the retaining arms 30.
In order to make manual uncoup~ing more dimc~Jlt, which is Jes;r~ in many cases for safety reasons, the ~"~ i",~r~L accor~ling to hg. 14 can be used, in which th~ projections 30a are shorter so that they do not project beyond the surface 15. D~spi~ this, unwupling by means of a tool such as a fork wrench 15 is easily possible.

~s shown in ~icular in hgs 16 and 17, In the coupled state the push fit conne~,~or can ~e at a very small ~;slance from th~ housing 3. ~pit~ this uncoupling is easihy possib'e - C~ r to a conven~ional push-fit con.~eclor 20 in which the latohing device is only ~ ssitle from the front of the push-fit connector. The pipe socket ~on"ing the fluid line 1 csn tl,~r~f~ re be conf~
corr~s}~ .lingly shorter.

~igs. 19 to 21 shaw ~he co-opef~lion of the retaining anns 18 wTth a fluid line 25 1, the retaining rib 2 of which has a different axial width be~ s~ of different t~le.~nces. The retaining rib 2 accor~ing to hg. 19 Is slightly narrower than that according to hg. 20, while th~ iny rib acoording to Fig. 20 is again so"l~v~h2l narrower than th~t accordin3 to Fig. 21. In all cases th~ tetaining rib 2 is l"~ cr received securely in the fece~ses 22 of the hooks 20 without 30 axial clearance because of the inclination or cun~ature r~s~otively of the inclined surfaces 23.

Claims

1. Push-fit connector for joining two fluid lines, one of which is provided with a retaining rib, comprising:
a sleeve having a central opening to receive the one fluid line with retaining rib, said sleeve having a plurality of apertures spaced around its circumference;
a latching device within said sleeve having a main body with at least one abutting surface cooperating with a surface within said sleeve to permit limited movement of said latching device within said sleeve along the sleeve longitudinal axis, said latching device having a pair of elastically flexible retaining arms spaced apart on and extending from said main body generally axially of the sleeve, each said retaining arm having a hook on its free end projecting toward said sleeve longitudinal axis for grasping behind the retaining rib of the one fluid line inserted axially into the latching device between said retaining arms to couple said latching device to the one fluid line, the inner surface of the free end of a hook having an inclined surface which, when said sleeve and said latching device and the one fluid line are moved toward each other, moves over the retaining rib of the one fluid line to spread the retaining arms apart to permit the hook to latch over the retaining rib, each hook also having an external part disposed in a respective aperture that is axially movable of the sleeve within the respective aperture, the front edge of the free end of a said hook having an outer surface inclined toward the sleeve axis which, when the one fluid line moves apart from the sleeve and retaining device, said hook becomes correspondingly more tightly engaged with the retaining rib by said hook front edge inclined outer surface within its respective aperture engaging the sleeve at a first edge of the respective aperture closest to said central opening, each hook also having an internal inclined surface which contacts the retaining rib when the latching device and inserted one fluid line are moved apart from one another to move the retaining arms radially outward of the one fluid line retaining rib and spread the retaining arms apart to allow uncoupling of the one fluid line from said latching device; and at least one unlatching arm extending generally axially of said sleeve from said latching device body between at least one pair of adjacent retaining arms and having an actuating part projecting outward through a respective one of said apertures to be engaged to move said locking device axially away from said sleeve central opening to uncouple the hooks of the retaining arms from the retaining rib of the one fluid line as the one fluid line is moved away from said locking device.

2. Push-fit connector according to claim 1, wherein the latching device main body comprises a ring on which said retaining and unlatching arms are formed for extending axially of said sleeve toward said sleeve central opening.

3. Push-fit connector according to claim 1 or 2, wherein at least one of said retaining and unlatching arms is provided with a surface part for contacting the edge of the aperture most remote from said sleeve central opening within which a respective arm is received for limiting axial movement of the latching device within the sleeve.

4. Push-fit connector according to claim 1, 2 or 3 wherein said hook of a retaining arm has a recess on its internal side for receiving the retaining rib of the one fluid line, the recess having on its side closest to said sleeve central opening an internal inclined surface of curved shape and on its side most remote from said sleeve central opening a curved surface, said recess dimensioned to receive a retaining rib of the one fluid line without any substantial clearance.

5. Push-fit connector according to claim 1, 2, 3 or 4 wherein an unlatching arm actuating part projects through its respective aperture beyond the outer surface of said sleeve in the area of the respective aperture.

6. Push-fit connector according to claim 1, 2, 3, 4 or 5 wherein the sleeve external surface includes a flattened area extending transversely of the sleeve longitudinal axis on each side of each said aperture receiving an unlatching arm, an unlatching arm actuating part extending through its respective aperture beyond the flattened area for a distance no greater than one of two different cylindrical sleeve external surface diameters on both axially adjacent sides of the aperture through which the unlatching arm actuating part extends, and an axial intermediate space provided between the part of the unlatching arm actuating part projecting out of its respective aperture and the surface of the sleeve with the larger of the two external surface diameters to leave a space for insertion of an unlatching tool.

7. Push-fit connector according to any one of claims 1 to 6 wherein there are two unlatching arms located diametrically opposite each other with respect to the sleeve longitudinal axis.

8. Push-fit connector according to claim 7, wherein each of said unlatching arms is flexible and has a partly cylindrical internal surface for engaging the radially external edge of the retaining rib at the one fluid line, said unlatching arm internal surface towards the free end of the respective unlatching arm being inclined.

9. Push-fit connector according to any one of claims 1 to 8 wherein each of said hooks includes a lateral projection for engaging the interior of the sleeve.

10. Push-fit connector according to any one of claims 1 to 9 wherein the free end of a said unlatching arm includes an external surface inclined toward said sleeve axis.

11. Push-fit connector as in any one of claims 1 to 10 further comprising at least one sealing ring between an inner shoulder of the sleeve and the latching device to seal the internal part of the sleeve.

12. A push-fit connector for interconnecting two fluid lines, one of the fluid lines having at least one external peripheral rib provided thereon, the connector being fittable to the other of the fluid lines and being capable of releasably retaining the one fluid line therewithin, the connector comprising:
a hollow sleeve having a plurality of apertures around its circumference;
a cylindrical latching device receivable and longitudinally movable within the hollow sleeve, the latching device comprising radially flexible elastic retaining arms each having a hook formed in a free end thereof, each hook being capable of engaging with the rib to secure the one fluid line within the connector, the hooks each having a radially outwardly extending projection loosely locatable within a respective one of the plurality of apertures to retain the latching device within the hollow sleeve and inwardly inclined internal and external surfaces for abutment with the rib and an edge of each aperture, respectively;
at least one sealing ring provided between an inner shoulder of the sleeve and the latching device; and at least one unlatching arm each locatable at least partly within one of said plurality of apertures and operable to allow separation of the one fluid line from the connector;
wherein, in use, movement to separate the one fluid line from the connector without operation of the unlatching arm causes the latching device to move such that each external inclined surface bears upon the edge of the respective aperture thereby more tightly to engage each hook with the rib; whereas movement to separate the one fluid line from the connector whilst operating the unlatching arm restrains movement of the latching device and causes the rib to bear upon each internal inclined surface thereby to axially move each hook out of engagement with the rib to allow separation of the one fluid line from the connector.

13. A push-fit connector according to claim 12, wherein the latching device comprises a ring on which the retaining and unlatching arms are moulded axially.

14. A push-fit connector according to claim 12 or claim 13, wherein at least one of the retaining and unlatching arms is provided with a radial contact surface abutable with an edge of a respective aperture opposite to the edge abutable by the inclined external surface of the hook, the contact surface serving to limit the insertion of the latching device within the hollow sleeve.

15. A push-fit connector according to any one of claims 12 to 14, wherein the hook is delimited on its axially external inner side by the radially internal inclined surface and on its axially internal inner side by a radial surface, the hook being dimensioned such that it is capable of receiving the retaining rib without any clearance, and regardless of the tolerances of its axial width.

16. A push-fit connector according to any one of claims 12 to 15, wherein the at least one unlatching arm projects beyond the circular cylindrical periphery of the sleeve in the area of the aperture in which it is received.

17. A push-fit connector according to any one of claims 12 to 16, wherein the external surface of the sleeve is provided with a flattened area extending transversely with respect to the longitudinal axis of the sleeve on both sides of each aperture receiving a respective one of the at least one unlatching arm, the at least one unlatching arm extending through a respective aperture and beyond the flattened area to provide an axial intermediate space between a part of the unlatching arm projecting out of the aperture and the surface of the sleeve thereby to allow the insertion of an unlatching tool.

18. A push-fit connector according to any one of claims 12 to 17, wherein two unlatching arms are provided diametrically opposite to one another with respect to the longitudinal axis of the sleeve.

19. A push-fit connector according to any one of claims 12 to 18, wherein the at least one unlatching arm is elastically flexible and is provided with a partly cylindrical internal surface fittable onto the radially external edge of the retaining rib, which surface merges towards the free end of the unlatching arm into an inclined surface.

20. A push-fit connector according to any one of claims 12 to 19, wherein the hooks are provided with lateral projections engageable with the interior of the sleeve.

21. A push-fit connector according to any one of claims 12 to 20, wherein the or each unlatching arm is provided with a radially outwardly inclined external surface on its free end.