Patent Description:
<CIT> and <CIT> disclose conventional quick connectors made of plastics. The connectors have first tongue portions protruding radially inwards for snapping engagement with the male part and second tongue portions protruding radially outwards for snapping engagement with the female part. Those conventional quick connectors have a constructional setup which is relatively complex and prone to damages. Indeed, the first and second tongue portions are connected to a ring-shaped base portion only by small webs which serve as hinge-joints for the flexing of the tongue portions. Those small web portions may break after a predetermined number of flexing operations or due to a fatigue of material. Further, the first and second tongue portions are provided at axially spaced portions of the connector so that the connector has a quite long axial extension.

<CIT> discloses a quick connector with the features in the preamble of present claim <NUM>. Further conventional quick connectors are described in <CIT> and <CIT>.

The object of the present invention is to reduce the weight and cost of the connector, to simplify its constructional setup and manufacturing effort, to shorten its axial extension and to improve its resistance against fracture even for long term use and repeated operations of its flexing parts.

The object is met by the quick connector defined in present claim <NUM>. The dependent claims relate to preferred embodiments and additionally call for a connection system comprising the quick connector and the male and female parts to be connected with each other.

In accordance with the present invention, the quick connector comprises a retaining means which is to be set within the mouth portion of the female part and which comprises first and second flexing members provided at circumferentially spaced portions for snapping engagement with the female part and the male part, respectively. Unlike the conventional solutions of quick connectors made of plastics, each pair of circumferentially adjacent first and second flexing members is interconnected by a web portion having a main longitudinal axis which extends directly from the first flexing member to the second flexing member. This simplifies the constructional setup and the manufacturing of the quick connector and allows to minimise the axial dimension thereof. Furthermore, the interconnection of adjacent first and second flexing members by the transversal web portions improves the radial resilience and decreases the risk of fracture even under long-term use.

According to a preferred embodiment of the present invention, the first flexing members are provided at a first axial end of the retaining means, and the second flexing members are provided at a second axial end of the retaining means which is opposite to the first axial end. The retaining means as a whole has the shape of a tapered ring whose diameter reduces from the second axial end to the first axial end, and which is provided with radial resilience by first gaps provided at the first axial end between two circumferentially adjacent first flexing members and second gaps provided at the second axial end between two circumferentially adjacent second flexing members.

The overall shape of the retaining means may have n-fold symmetry, n being an integer, wherein n=<NUM> in the most preferred embodiment.

The web portions connect the first and second flexing members in a zig-zag shape along the circumferential direction of the retaining means. Hence, the overall shape of the retaining means can also be described as a number (most preferably six) of V-shaped ring segments which are interconnected at their adjacent arms to form a crown.

According to a preferred embodiment of the invention, the main longitudinal axis of each web portion forms an inclination to the axial direction of the quick connector, said inclination being described by two angles: a first angle α giving the amount by which the web portion is inclined radially inwards from the second flexing member to the first flexing member, and a second angle β giving the amount by which the web portion is inclined in a circumferential direction of the retaining means from a second flexing member to the circumferentially adjacent first flexing member. Preferably, the first angle α is between <NUM>° and <NUM>°, in particular between <NUM>° and <NUM>°, and the second angle β is between <NUM>° and <NUM>°, in particular between <NUM>° and <NUM>° to reach a retaining means with good characteristics in terms of stability and flexibility.

The design of the crown-like retainer ring with the comparatively small tapering towards the axial direction results in that only a small insertion force is needed to push-in the male part. The inward angle of the flexing members is very low, but it is possible to use the full axial length of the retainer ring for the inserting process of the male part during which the retainer ring as a whole has the possibility to expand in the radial direction. This in combination yields a required insertion force which is low but guarantees a high resistance force against pulling out the male part.

The front surface of the retaining means at the first axial end which comes next to the sealing means may be enlarged by web portions having a tapered form so that the width of the web portions reduces along the main longitudinal axis from the first flexing members to the second flexing members. This allows to enlarge the contact area between the first axial end of the retaining means and the sealing means or a washer optionally interposed between the retaining means and the sealing means.

Preferably, the retaining means is made of a polymer-based plastics material. It is particularly preferable to form the retaining means as an integral structural body by injecting moulding or the like from mouldable plastics material. Thereby, the production costs and the durability of the connector achieve most competitive values.

According to the present invention, the quick connector further comprises releasing means having a ring portion with an appropriate outer diameter to bend the first flexing members in the radial direction to be disengaged from the male part when the releasing means is pushed towards the lower (first) axial end of the retaining means. The pushing operation is alleviated by a gripping part which is connected to the ring portion and provided axially spaced therefrom so as to protrude from the mouth portion of the female part. Radial protrusions are provided at the outer circumference of the ring portion to allow a latching engagement into a notch-like first gap between two adjacent first flexing members.

The sealing means, preferably an O-ring, an X-seal, or a lip seal, is positioned axially frontwards of the retaining means within the mouth portion of the female part. The sealing position does not axially overlap with the retaining means so that the sealing means is able to contact both the male part and the female part when the quick connector is in its locked condition. Thereby, one single sealing position is sufficient for the coupling between the male and female parts so that there is only one single potential leakage position.

Details of the invention and its embodiments will be explained with reference to the accompanying drawings. Therein shows:.

<FIG> show the retaining means <NUM> in different views. The shown retaining means <NUM> is made of plastics material, more specifically of a polymer-based plastics material, and is even more specifically obtained as an integral body by injection moulding or the like. The retaining means <NUM> has the overall shape of a tapered ring that has radial flexibility by a number of triangular gaps <NUM>, <NUM> provided alternating on the first and second axial ends of the retaining means.

Due to the fact that the diameter of the ring-like retaining means increases from the first (lower) axial end to the second (upper) axial end, the rim portion of the retainer ring <NUM> at the upper portion protrudes radially outwards and the rim portion at the lower portion protrudes radially inwards. Due to the upper gaps <NUM> and the lower gaps <NUM> in combination with the general characteristics of the plastic material, the rim portions between the lower gaps <NUM> form first (lower) flexing members <NUM>, and the rim portions between the upper gaps <NUM> form second (higher) flexing members <NUM>. In other words, the first and second flexing members <NUM>, <NUM> have elastic deformability in the radial direction, i.e. they can be flexibly deformed to a certain extent in a radial direction orthogonal to the axial extension X of the tubular retaining means <NUM>.

Each pair of adjacent first and second flexing members <NUM>, <NUM> is interconnected by a transversal web portion <NUM>. Each web portion <NUM> is inclined with respect to the axial direction X, more specifically, the main longitudinal axis L of each web portion <NUM> cross-connecting a pair of adjacent first and second flexing members <NUM>, <NUM> is inclined. The inclination may be described by two angles α and β. The first angle α specifies the amount of tapering of the retainer ring <NUM>, i.e. the degree by which the outer diameter decreases from the second axial end to the first axial end. The second angle β specifies the amount of circumferential inclination of the transversal web portion <NUM>, i.e. the amount by which the main longitudinal axis L of the web portion <NUM> deviates from a straight projection of the axial direction X to the (tapered) outer circumferential surface of the retainer ring <NUM>.

In the shown embodiment, the inner surface of the web portions <NUM> is not flat but has a shoulder portion <NUM>. This shoulder portion <NUM> serves as a rest for the lower axial end of the male part <NUM> in the non-connected state and for the ring portion <NUM> of a releasing means <NUM> in a connected state as will be described later on with respect to <FIG> and <FIG>. The shoulder portion <NUM> is merely an optional feature and the funnel-like inner surface of the web portions <NUM> may also be flat (just as the outer surface) providing the same performance of the retainer ring <NUM> in terms of radial resilience and stability.

In the shown embodiment, there are six first and six second flexing members <NUM>, <NUM>. Hence, the tubular retaining means <NUM> has a six-fold rotational symmetry and may be formed by interconnecting six V-shaped ring segments. However, solutions with more or less than six first and six second flexing members <NUM>, <NUM> and even a deviation from the generally n-fold rotational symmetry are possible. In particular, there may be just two first second flexing members <NUM> and two second flexing members <NUM> cross-connected by just four web portions <NUM>.

In the perspective exploded view of present <FIG>, the retaining means <NUM> is shown in its pre-assembled state axially next to a sealing means <NUM> and in between the tubular male part <NUM> and the female part <NUM>. The assembled position is shown in <FIG>. Each of the cross-sectional views in <FIG>, <FIG>, <FIG> and <FIG> is taken along the middle axis of two of the notch-like lower gaps <NUM> formed between two adjacent first flexing members <NUM>.

In the perspective view of the fluid connection system shown in <FIG>, the female part <NUM> is formed as a hole in a block. While conventional fluid connection systems provided an inner threading in the hole for screwing a threaded portion of the connector, the mouth portion <NUM> of the female part <NUM> is adapted to fully receive and engage with the connector without such threaded portion. The inserting direction of the spigot <NUM> extends downwards in the Figure and is hereafter designated as the frontward direction. The opposite direction is designated as the backward direction.

The female part <NUM> has a mouth portion <NUM> which has a diameter large enough to receive the male part <NUM> encircled with the sealing means <NUM>. The mouth portion <NUM> has a step portion <NUM> with increased diameter serving as an axial rest for the sealing means <NUM>. Within the mouth portion <NUM> and spaced apart from the upper axial end thereof, the female part <NUM> has a recessed portion <NUM> having a larger diameter than the rest of the mouth portion <NUM>. The axial length of the recessed portion <NUM> is about the same as the axial length of the retainer ring <NUM>.

The diameter of the mouth portion <NUM> at the upper axial end is smaller than the outer diameter of the second flexing members <NUM> in their relaxed state. By pushing the retaining means <NUM> in the downward direction into the mouth portion <NUM>, the second flexing members <NUM> will elastically deform radially inwards so that their outer diameter becomes small enough to enter the mouth portion <NUM>. As soon as the second flexing members <NUM> will reach the axial position of a recessed portion <NUM> formed axially distant from the outer surface of the mouth portion <NUM>, the second flexing members <NUM> will relax into their original state and snappingly engage with the groove-like recessed portion <NUM> of the female part <NUM>.

The state in which the second flexing members <NUM> snap into the recessed portion <NUM> when the retaining means <NUM> is pushed in the frontward direction into the mouth portion <NUM> can be seen best in <FIG>. Since the second flexing members <NUM> then abut against the upper edge of the recessed portion <NUM>, the retaining means <NUM> cannot be taken out from the mouth portion <NUM> anymore unless the second flexing members <NUM> are bent radially inwards.

Similarly, the male part <NUM> has a recessed portion <NUM> with a smaller outer diameter and spaced apart from the frontward axial end of the male part <NUM>. The shaping of the male part <NUM> is shown in greater detail in <FIG>. When the male part <NUM> is pushed through the retainer ring <NUM> in the frontward direction, the first flexing members <NUM> snap into the recessed portion <NUM> as can be seen best in <FIG>. Hence, the first flexing members <NUM> abut against the upper edge of the recessed portion <NUM>, and the male part <NUM> cannot be taken out from the retaining means <NUM> anymore without bending the first flexing members <NUM> radially outwards.

Thereby, the connection state shown in present <FIG> is obtained, in which the sealing means <NUM> and the retaining means <NUM> reach a locked state and the retaining means <NUM> is engaged with the female part <NUM> by the snapping interaction between the second flexing members <NUM> and the recessed portion <NUM>. As can be seen from present <FIG>, the retaining means <NUM> does not protrude axially from the female part <NUM> but is fully received within its mouth portion <NUM>. This is of particular advantage for processing and delivering the female part <NUM> with the retaining means <NUM> in this pre-locked state. Further, the retaining means <NUM> stops the sealing means <NUM> from falling out of the mouth part <NUM> due to its locked axial positioning. The sealing means <NUM> rests at a step portion <NUM> of the female part <NUM>. The step <NUM> has a larger diameter than the axially adjacent portion in the downward direction of the female part <NUM> so that the sealing means <NUM> cannot move further inward into the female part <NUM> either.

An O-ring <NUM> as the sealing means is to be positioned at the annular step <NUM> (see <FIG>) formed at the frontward region of the mouth portion <NUM>. The O-ring <NUM> and the other parts of the connector are shown in <FIG> axially distant from the mouth portion <NUM>, and the spigot <NUM> as the male part is shown axially spaced even more backward therefrom. In order to establish the fully connected state of the fluid connection system shown in <FIG>, the sealing means <NUM> is first positioned within the mouth portion <NUM> at the step portion <NUM> of the female part <NUM>, the ring-shaped retaining means <NUM> is then positioned axially backwards and adjacent to the sealing means <NUM>.

The connector already comes into a pre-locked engagement state when being inserted into the mouth portion <NUM>. This is because the second flexing member <NUM> of the retaining means <NUM> will undergo some compression when entering the mouth portion <NUM> and will then snap into the recessed portion <NUM> of the female part <NUM>. Thereby, the second flexing member <NUM> prevents the retaining means <NUM> and the sealing means <NUM> from falling out of the mouth portion <NUM> during transport or the like.

Finally, the male part <NUM> is pushed through the retaining means <NUM> and the sealing means <NUM> until the first flexing members <NUM> which protrude radially inwards form a snapping engagement with the recessed portion <NUM> of the male part <NUM>. The ratchet formed at the backward end of the recessed portion <NUM> abuts against the first flexing members <NUM> so that the male part <NUM> remains locked within in the connector <NUM> and cannot be moved backwards anymore.

The sealing means <NUM> is expanded when the male part <NUM> is pushed through the retaining means <NUM> and the sealing means <NUM> into the fully locked position shown in present <FIG>. Thereby, the fluid connection system reaches a state in which the male part <NUM> is fully sealed against the female part <NUM>. This is due to the fact that the most frontward portion of the male part <NUM> has an outer diameter which is slightly larger than the inner diameter of the sealing means <NUM> so that the sealing means <NUM> has to expand radially when the male part <NUM> is pushed through with its most frontward portion.

<FIG> show an example not according to the present invention which distinguishes from the first embodiment shown in <FIG> only in that a washer <NUM> is positioned axially between the retainer ring <NUM> and the sealing means <NUM>. Since the presence of the washer <NUM> forms the only distinction to the first embodiment described above, only this part will be described now and the other parts are just shown in the drawings without description and designation by reference signs.

The washer or spacer <NUM> rests on the frontward edge of the recessed portion <NUM> of the female part <NUM> and serves as a circumferentially uniform stopper for the sealing means <NUM> in the axial direction X. This is particularly important when the sealing means is radially expanded by insertion of the male part <NUM>. The washer <NUM> then blocks the sealing means <NUM> from deforming in the axial direction. In particular, the sealing means <NUM> cannot enter into the notch-like gaps <NUM> formed between the first flexing member <NUM> at the lower axial end of the retainer ring <NUM> under pressure.

As shown in the drawings, the washer <NUM> has radial protrusions <NUM>. The protrusions <NUM> help to position the washer <NUM> within the mouth portion <NUM> and stop the washer <NUM> from falling too far into the female part <NUM>. As shown in the drawings, four protrusions <NUM> may be arranged circumferentially in a <NUM>-fold symmetry. Other arrangements or numbers of protrusions are, of course, possible, as well as a washer <NUM> without any such protrusions <NUM>.

After the male part <NUM> is inserted, the retaining means <NUM> may also be manipulated with a secondary latching operation (e.g., by a latching tool not shown) in the frontward direction to close the gaps <NUM> so as to provide a flat retainer surface towards the upper surface of the sealing means <NUM>. Thereby, the fluid connection system comes into the fully locked and sealed state with tight and uniform compression of the sealing means <NUM> from both axial ends even without providing any washer <NUM>.

<FIG> show releasing means <NUM> which may be used as a tool for unlocking the male part <NUM> from the snapping engagement with the first flexing members <NUM> of the retaining means <NUM>. The releasing tool <NUM> has a ring-shaped portion <NUM> having a diameter which is larger than the diameter of the first axial end of the retainer ring <NUM> formed by the first flexing members <NUM> but smaller than the diameter of the second axial end of the retainer ring <NUM> formed by the second flexing members <NUM>. As shown in <FIG>, the ring portion <NUM> may therefore be used to flex the first flexing members <NUM> radially outwards in order to release the recessed portion <NUM> of the male part <NUM> from the retainer ring <NUM>.

The releasing means <NUM> further has a gripping portion <NUM> which is designed to remain outside the mouth portion <NUM> and which allows an operator to operate the releasing means <NUM> in order to disengage the male part <NUM> by a pushing operation into the frontward direction when necessary. The ring portion <NUM> has six windows <NUM> which are circumferentially positioned to correspond to the positions of the second flexing members <NUM> in the connected state shown in <FIG>. Below two diametrically opposite windows <NUM> the ring portion <NUM> has a radial protrusion <NUM> for engagement with the notch-like gaps <NUM> between two adjacent first flexing members <NUM> of the retainer ring <NUM>. The number of the windows <NUM> and protrusions <NUM> may be chosen in an appropriate manner and is not limited to the shown embodiment.

As shown in <FIG>, the releasing means <NUM> is axially positioned such that its ring portion <NUM> is engaged within the retainer ring <NUM>. In particular, the wedge-like protrusions <NUM> are received within the lower gaps <NUM> and the second flexing members <NUM> are received within the windows <NUM>. This means a secure and defined radial positioning of the releasing means <NUM> within the retainer ring <NUM>. The axial positioning is given by the shoulder portion <NUM> at the inside surface of the web portions <NUM>. The releasing tool <NUM> abuts and rests against these shoulder portions <NUM> in the relaxed and fully connected state shown in <FIG>.

Now, the operator can push the releasing means <NUM> axially frontwards by use of the gripping portion <NUM>. The operator will feel a certain resistance against this pushing operation because the axial frontward end of the releasing means <NUM> is in the rest position abutting against the shoulder portions <NUM> of the web portions <NUM>. When overcoming this resistance, the ring portion <NUM> will expand the first flexing members <NUM> radially outwards in order to release their engagement with the recessed portion <NUM> of the male part <NUM>. As soon as the operator takes hands off, the releasing means <NUM> will move back into the relaxed state due to the elastic flexibility of the retaining means <NUM> in the radial direction.

<FIG> show an embodiment of the present invention which distinguishes from the embodiment shown in <FIG> only in that a washer <NUM> is positioned axially between the retainer ring <NUM> and the sealing means <NUM>. Just as in <FIG>, the washer or spacer <NUM> rests on the frontward edge of the recessed portion <NUM> of the female part <NUM> and serves as a circumferentially uniform stopper for the sealing means <NUM> in the axial direction X.

<FIG> show another type of female part 40A to be used with another embodiment of the present invention. This female part 40A is the end of a pipe or tube and not formed as a hole in a block as described in the other embodiments. However, the same principles as explained with respect to the other embodiments also apply to this embodiment. The female part 40A has a mouth portion 41A in which the recessed portion 42A and the step portion 43A are formed in the same way as explained further above with respect to <FIG>.

<FIG> show the use of the female part 40A as described in combination with <FIG> in an embodiment. The individual parts and their functions are the same as in the third embodiment shown in <FIG> except that the block-like female part <NUM> is replaced by the tube-like female part 40A. Hence, the description of the functionality of the parts in <FIG> applies mutatis mutandis to <FIG>.

Of course, the washer <NUM> could be added to the embodiment similar to what is shown in <FIG> and/or the releasing means may be omitted from the embodiment similar to what is shown in <FIG> and <FIG>.

In summary, the present invention provides a quick connector made of plastics material for establishing a snapping connection between a tubular male part <NUM> and a female part <NUM> of a fluid connection system. The connector has retaining means <NUM> adapted to be set within the mouth portion <NUM> of the female part <NUM> and having first and second flexing members <NUM>, <NUM> for snapping engagement with the male part <NUM> and the female part <NUM>, respectively. Each pair of circumferentially adjacent first and second flexing members <NUM>, <NUM> is cross-connected by a transversal web portion <NUM> having a main longitudinal axis L which extends directly from the first flexing member <NUM> to the second flexing member <NUM>.

Claim 1:
A quick connector for connecting a tubular male part (<NUM>) in an axial direction (X) to a female part (<NUM>; 40A), comprising:
sealing means (<NUM>) adapted to be set within a mouth portion (<NUM>; 41A) of the female part (<NUM>; 40A) to form a seal between the male part (<NUM>) and the female part (<NUM>; 40A);
retaining means (<NUM>) adapted to be set within the mouth portion (<NUM>; 41A) and having at least two first flexing members (<NUM>) protruding radially inwards for snapping engagement with the male part (<NUM>) and at least two second flexing members (<NUM>) protruding radially outwards for snapping engagement with the female part (<NUM>), wherein each pair of circumferentially adjacent first and second flexing members (<NUM>, <NUM>) is connected by a web portion (<NUM>) having a main longitudinal axis (L) which extends directly from the first flexing member (<NUM>) to the second flexing member (<NUM>); and
releasing means (<NUM>) which includes:
a ring portion (<NUM>) having an outer diameter which is larger than the inner diameter of the retaining means (<NUM>) at a first axial end at which the first flexing members (<NUM>) are provided but smaller than the inner diameter of the retaining means (<NUM>) at a second axial end at which the second flexing members (<NUM>) are provided; and
a gripping part (<NUM>) connected to the ring portion (<NUM>) and provided axially spaced from the ring portion (<NUM>) so as to protrude from the mouth portion (<NUM>; 41A) of the female part (<NUM>; 40A),
wherein the gripping part (<NUM>) allows an operator in a releasing operation to push the ring portion (<NUM>) towards the first axial end of the retaining means (<NUM>) so that the first flexing members (<NUM>) are bent in the radial direction and disengage from the male part (<NUM>),
characterised in that the outer circumference of the ring portion (<NUM>) has at least one radial protrusion (<NUM>) for latching into a notch-like first gap (<NUM>) between two adjacent first flexing members (<NUM>).