DESCRIPTION

Technical Field

The present invention relates to a female terminal for rapid-fit connections. The invention is applicable to the field of rapid-fit connections able to realize, rapidly and safely, the connecting and disconnecting operations of two different conduits crossed by fluids or gases under pressure, avoiding manual blocking operations which require the use of wrenches or other tools and ensuring both the mechanical seal and the hermetic seal. The use of the rapid connections is made necessary, for example, when work units are connected and set in operation that require connection to pneumatic/oil-dynamic/hydraulic circuits, for agricultural machines, earth-moving machines, pumps, hydraulic/pneumatic cylinders, valves, etc. In more detail, the present invention finds application in the sector of female terminals engageable with male terminals constrained by international standards that are non-modifiable.

Prior Art

Female terminals are known for manually-actuab!e rapid-fit connections, with push-pull modalities, in which the connecting step is done by gripping the male nipple and pushing it into the female part up until the female part mechanically retains the male nipple and the disconnection step is done by smartly extracting the male nipple from the female part.

These known terminals usually exhibit an engaging system on the male terminal of the ball-bearing type. In greater detail, these terminals comprise an external cylindrical body provided with two annular cavities axially spaced and fashioned on a radially internal surface thereof located in proximity of the engaging end with the male terminal. The above-mentioned terminals further comprise a radially-internal cylindrical body axially mobile with respect to the external cylindrical body and provided with a series of radial through-openings enabling partial passage of a plurality of coupling ball bearings through the internal body and the engagement thereof in an annular seating of the male terminal. Published documents US 4,974,635, US 6,776,187, EP 1 625 322 disclose, for example, female terminals of the above-described type.

Also known is document US 2008/0289702 (also EP1963729), which illustrates a fitting device for pressurized fluid conduits which comprises a valve exhibiting a sliding stop element, having a tubular shape and realized in an elastically deformable material. The stop element comprises at least an external radial projection destined to enter into contact with a corresponding internal radial projection of an internal mobile body containing the valve. The simultaneous retracting of the internal mobile body and the valve with respect to an external body has the effect of causing the sliding stop element radially contract up until the external radial projection passes over the internal radial projection.

Also known is published document WO 97/1 302 which illustrates a rapid coupling comprising a slidable tubular sleeve arranged behind a valve and exhibiting a front abutment surface. The valve comprises a second sliding sleeve exhibiting a rear end profiled such as to engage with the front abutment surface of the tubular sleeve. Blocking and return means (defined by a spring, a conical ring and bail bearings) engage the sleeve so as to return the front abutment surface into an advanced position.

Aim of the Invention

In this context, the Applicant has set the objective of providing a female terminal for rapid-fit connections that is qualitatively superior, more economical and more compact than those of the prior art.

The Applicant in particular set itself the objective of providing a female terminal for rapid-fit connections which guarantees a stable and low-turbulence flow of fluid which transits through with a movement and a positioning of the internal moving organs that is precise (in particular, though not only, the obturator).

The Applicant has also set itself the objective of providing a female terminal for rapid-fit connections which is axially compact and therefore does not occupy a great deal of space.

The Applicant has also set itself the objective of providing a female terminal for rapid-fit connections which comprises a limited number of easily-assemb!able parts and is therefore economical to produce and mount. Summary of the invention

The Applicant has found that these objectives and others besides can be obtained by realising a female terminal for rapid-fit connections according to the present invention, of the type claimed in the accompanying claims and/or described in the following sentences.

More specifically, the present invention relates to a female terminal for rapid-fit connection of a type comprising:

a first body that is substantially tubular and exhibits a main axis;

a second body that is substantially tubular and is coaxial to and internal of the first body and axially mobile with respect to the first body;

a plurality of coupling ball bearings operatively active at a first end of the female terminal, which first end can accommodate a male terminal provided with an annular cavity, wherein the coupling ball bearings are radially mobile such as to engage in the annular cavity and axially block the male terminal;

an obturator mounted internally of the second body and axially mobile between a closed position and an open position of an axial conduit delimited by the female terminal.

The female terminal delimits an axial conduit for fluid passage and exhibits a first end associated to a male terminal and a second end, opposite the first end, to be fitted to a pipe/conduit.

The second body preferably delimits a first opening of the conduit which opens on the first end and, preferably the first body delimits a second opening of the conduit which opens on the second end and preferably bears a thread for the tube to be fitted.

The first body is preferably provided with a (hollow) first annular seating (or a plurality of first seatings arranged on a first annular pathway) and a second annular seating (or a plurality of second seatings arranged on a second annular pathway) and axially spaced from the first annular seating, the first and second annular seating being arranged on a radially internal surface of the first body and being able to house the coupling ball bearings alternately (in the first annular seating or the second annular seating).

The second body preferably exhibits a circumferential series of radial passages for enabling partial passage of the coupling ball bearings through the second body and the engaging thereof in the annular seating in the male terminal. A main spring is preferably operatively active between the first body and the second body along an axial direction such as to push the first body towards the first end of the female terminal.

At least an auxiliary spring is preferably interposed between the obturator and the second body so as to axially push the obturator to close against an abutment surface delimiting the axial conduit.

The coupling ball bearings are radially mobile between a radially external position, when they lie internally of the first annular seating or the second annular seating, and a radially internal position, when they are positioned in the radial passages (the shape of which is such as to retain them and not cause them to exit therefrom). When they are in the radial passages, the relative axial movement between the first body and the second body enables displacing the coupling ball bearings (all together) between the first seating and the second seating. When the axial position is such that the coupling ball bearings are between the first seating and the second seating, a contrast surface belonging to the first body together with a radially internal edge of each of the radial passages block the coupling ball bearings in the radially interna! position.

The female terminal preferably comprises a guide element of the obturator mounted in the second body and coupled to the obturator. The guide element radially blocks the obturator with respect to the second body and axially guides the sliding of the obturator.

The guide element preferably comprises a plurality of peripheral appendages developing substantially parallel to the main axis, radially elastic and exhibiting terminal engaging ends.

The peripheral appendages are preferably at least three in number.

The peripheral appendages are preferably angularly equidistanced from one another.

The terminal engaging ends are preferably projected radially towards the outside. A radially internal surface of the second body preferably exhibits a plurality of main housings (or a single main housing) able to accommodate the terminal engaging ends and to prevent any relatively axial movement between the guide element and the second body.

The terminal engaging ends exhibit dimensions with respect to the main housings that are such as to enable insertion and exit thereof along radial directions, but at the same time to prevent axial displacement in both directions when the terminal engaging ends are inserted in the main housings.

In other words, when the terminal engaging ends are inserted in the main housings, opposite edges of the main housings lie resting against the terminal engaging ends and prevent any axial displacement thereof in both directions.

The Applicant has found that the axial block of the guide element with respect to the second body advantageously enables ensuring that the axial position of the obturator, when it acts against the obturator of the male terminal and the valve they form is open and under pressure, is stable. In this way, the passage section is maintained constant also in the presence of changes of the flow state of fluid or even inversions in the flow direction.

The guide element has a double function: it guides the obturator and blocks it in position.

The female terminal preferably comprises means for expelling the terminal engaging ends from the respective main housings and for enabling an axial movement of the guide element with respect to the second body.

The means for expelling the terminal engaging ends preferably comprise a plurality of auxiliary ball bearings, each operatively active on a respective terminal engaging end.

The second body preferably exhibits a plurality of auxiliary radial passages in communication with the main housings (or with the single annular housing) in order to allow partial passage of the auxiliary ball bearings across the second body and engagement thereof against the terminal engaging ends.

The auxiliary ball bearings are preferably mobile between a radially external position, in which they are completely accommodated in the main housings, and a radially internal position, in which they partially project across the main housings in order to expel the terminal engaging ends from the main housings and to enable axial movement between the guide element and the second body

The peripheral appendages are radially flexible towards the main axis due to the thrust exerted by the expelling means.

The number and the distance between the peripheral appendages is such as to enable the radial flexion substantially without reciprocal interference.

The first body preferably exhibits an auxiliary annular seating (or a plurality of auxiliary seatings arranged on an annular pathway) for the auxiliary ball bearings. When lying in the auxiliary annular seating, the auxiliary ball bearings are preferably in the radially external position.

The relative axial movement between the first body and the second body determines the passage of the auxiliary ball bearings between the radially external position and the radially internal position. In the radially external position, the auxiliary ball bearings lie in the auxiliary annular seating (and preferably also in the auxiliary radial passages). In the radially internal position, the auxiliary ball bearings lie outside the auxiliary annular seating, in contact with a radially internal surface of the first body and retained in the auxiliary radial passage by radially internal edges of the main housings (the profile of the radial passages and the main housings, or the sole annular housing, is such as to retain the ball bearings and not cause them to exit).

The Applicant has verified that the ball bearing mechanism advantageously ensures that the insertion and deinsertion of the terminal engaging ends in/from the main housings occurs without obstacles and with safety and precision.

The expulsion of the terminal engaging ends determines an elastic flexion of the peripheral appendages towards the main axis (contraction).

The second body preferably exhibits a second annular housing, for the terminal engaging ends, axially offset with respect to the main housings.

The terminal engaging ends are preferably alternatively engageab!e in the main housings or in the secondary annular housing by means of an axiai movement of the guide element with respect to the second body.

Once they have reached the secondary annular housing, the terminal engaging ends enter therein, pushed by the elastic return of the peripheral appendages. The secondary annular housing preferably exhibits an entry surface able to facilitate the inlet and outlet of the terminal engaging ends.

The second annular housing is used to temporarily retain the guide element on the second body in an axial position that is different from the stable position ensured by the main housings, as will more clearly emerge from the explanation of the functioning provided in the following. This position is the male-female engaging position carried out still without pressurized fluid injected through the female terminal.

The peripheral appendages preferably fie radially flanked to the radially internal surface of the second body. When the terminal engaging ends are engaged in the main housings or in the secondary annular housing, the peripheral appendages are preferably in contact with the second body over a whole length thereof.

When the terminal engaging ends are not engaged in the main housings nor in the secondary annular housing and lie in contact with the radially internal surface of the second body, the peripheral appendages are preferably radially flexed towards the main axis and lie partially in contact with the second body.

A first auxiliary spring is preferably operatively active between the guide element and the obturator along an axial direction such as to push the obturator towards the first end of the female terminal.

A second auxiliary spring is operatively active between the guide element and the second body along an axial direction such as to push the guide element towards the first end of the female terminal.

The presence of the two springs advantageously enables pushing the obturator elastically against the obturator of the male terminal or in closure against the abutment surface even when the guide element is axially blocked.

The guide element preferably comprises a central body exhibiting a passage for a pin of the obturator.

The guide element preferably comprises a plurality of radial arms, each bearing one of the peripheral appendages.

The structure ensures a considerable passage section for the fluid (between the radial arms) and at the same time a sufficient rigidity of the various elements.

The guide element preferably comprises a radially external ring connecting the radial arms.

The radially external ring advantageously facilitates the contacting sliding with the second body and increases the rigidity of the guide element.

The female terminal preferably comprises at least a reference pin located in a radial seating of the second body and exhibiting a cavity for one of the peripheral appendages, such as to prevent a relative rotation between the guide element and the second body but enable a relative axial sliding between the two elements.

The reference pin is preferably located removable in the radial seating.

The reference pin advantageously ensures that the guide element is mounted with ease in the correct angular position in the second body and can also be easily demounted. In fact, the reference pin aligns the peripheral appendages and the terminal engaging ends with respect to the auxiliary ball bearings.

The reference pin is preferably located removably in the radial seating.

The female terminal preferably comprises a third body that is substantially tubular, coaxial and external of the first body and axially mobile with respect to the first body.

The first body and the third body preferably delimit an annular chamber in fluid communication with a second end of the female terminal.

A fluid pressure exerted in the annular chamber preferably pushes the first body towards the first end of the female terminal.

A third auxiliary spring is preferably operativeiy active between the third body and the first body along an axial direction such as to thrust the first body towards the first end of the female terminal.

The first body and the second body preferably exhibit radial through-holes communicating with the annular chamber and with the second end of the female terminal.

The third pressurised chamber guarantees the reciprocal sealed blocking of the two terminal in working conditions.

The Applicant has found that the presence of the third radially external body advantageously enables ensuring the necessary functions while containing the axial development of the female terminal which therefore is more compact with respect to terminals of known type.

The third body preferably comprises an endrun located at the first end and operativeiy active on the first body and the second body.

The endrun is a portion of the third body preferably developing radially towards the main axis.

The endrun of the third body leaves the second body to project radially towards the main axis so as to enable the second body to perform a centring function for the male terminal.

The second body preferably comprises two reciprocally-screwed cylindrical half- parts.

The third body preferably comprises two reciprocally-screwed cylindrical half-parts. The structure advantageously enables mounting/demounting the female terminal with great simplicity. The female terminal of the invention is simpler to assemble and economical to produce.

The obturator and the guide element are preferably inserted in the second body on opposite sides with respect to the first end and blocked for example using a stop ring. Then the second body (with the coupling ball bearings and the auxiliary ball bearings in the respective radial passage) is axially inserted in the first half-part of the first body to be fitted to the pipe/conduit. The second half-part of the first body is inserted on the second body and screwed to the first half-part. The first/second body assembly is inserted in the first or second half-part of the third body and lastly the other second or first half-part of the third body is screwed on the first/second ha!f-part.

The above-described preferred characteristics can be present either singly or in combination in the female terminal according to the invention. In particular, the guide element with all its characteristics and the third body with all its characteristics can be both or singly present in the female terminal according to the present invention.

The device of the invention, owing to the adopted constructional choices, can be used for very broad-ranging uses and in various sectors, especially in the agricultural sector, but also in the industrial sector in which pressure and flow rate, and more in general all the variable of the working conditions, can vary from very modest values to very high values.

Brief description of the drawings

Further characteristics and advantages will more fully emerge from the detailed description of a preferred but not exclusive embodiment of a female terminal for rapid-fit connections according to the present invention.

The description will be made in the following with reference to the appended drawings, provided by way of non-limiting example, in which:

- figure 1 is a section according to two axial planes of a female terminal according to the present invention;

- figure 1A illustrates a male terminal of known type to be fitted in the female terminal; - figures 2-7 each show the female terminal of figure 1 in respective operating conditions with the male terminal of figure 1A;

- figures 8a and 8b are views of a female terminal element illustrated in the preceding figures;

- figure 9 illustrates a different element of the female terminal illustrated in the preceding figures.

Detailed Description of a Preferred Embodiment of the invention.

With reference to figure 1 , 1 denotes in its entirety a female terminal for rapid-fit connections according to the present invention.

The female terminal 1 is preferably couplable to a male terminal 100 which is of known type, constrained by international standards and not forming part of the present invention.

The male terminal 100 comprises a cylindrical body 101 exhibiting a first end 102 engageable in the female terminal 1 and a second end 03 (internally threaded) associable to a pipe and internally delimits a passage conduit 104 which opens on the first and the second ends 102, 103 into a first 105 and a second 106 opening. An obturator 107 is mounted in the passage conduit 104 and is pushed to close against an abutment surface of the first opening 105 by a spring 108. The cylindrical body 101 exhibits, on a radially external surface thereof, an annular cavity 109 delimited by an annular body in relief 110.

The female terminal 1 exhibits a first end 2 engageable with the male terminal 100 and a second end 3, opposite the first end 2, associable to a pipe and delimits internally thereof an axial conduit 4 which develops along a main axis X~X and opens on the first and the second ends 2, 3 in a respective first opening 5 and second opening 6.

The female terminal 1 comprises a substantially tubular first body 7 which develops along the main axis X-X and is formed by a first half-part 7a and a second half-part 7b, both substantially cylindrical, coaxial, axiaily aligned and screwed one to the other.

The first body 7 internally exhibits a first annular seating 8 (recess) arranged on a radially internal surface of the first body 7. The first body 7 further exhibits a second annular seating 9 (recess) arranged on the radially internal surface of the first body 7. The two annular seatings 8, 9 are axiaily distanced such as to delimit between them an annular contrast surface 10. The first annular seating 8 and the second annular seating 9 are positioned at an axial end 7c of the first body 7 in proximity of the first end 2 of the female terminal 1. The first body 7 internally exhibits, in an axially more interna! position with respect to the first and second seatings 8, 9, an annular recess 11 which exhibits two facing rest surfaces and houses a main spring 12 of a helical type. Moving towards the second end 3 of the female terminal 1 , the first body 7 internally exhibits a narrowing of the axial conduit 4 which defines a first endrun surface 13 facing towards the first end 2. Moving further towards the second end 3 of the female terminal 1 , the first body 7 exhibits an auxiliary annular seating 14 (recess) having an elongate shape in the direction of the main axis X-X. The auxiliary annular seating 14 is also arranged on the radially internal surface of the first body 7. Moving further towards the second end 3 of the female terminal 1 , the first body 7 internally exhibits a further narrowing which defines a second endrun surface 15 facing towards the first end 2. The radially internal surface of the first body 7 terminates at the second end 3 with a threaded portion 16. A radially external surface of the first body 7 exhibits a radial narrowing (moving from the first towards the second end 3) which delimits a first rest surface 17 facing towards the second end 3. Through-holes 18 radially cross the wall which defines the first body 7 and are located flanked to the first rest surface 17.

The female terminal 1 comprises a substantially tubular second body 19 which develops along the main axis X-X and is formed by a single body. The second body 9 is mounted coaxiaily in the first body 7 so as to slide axially in the first body 7. The second body 19 exhibits a circumferential series of radial passages 20 arranged along an annular pathway which lies in a radial plane, perpendicular to the main axis X-X. The radial passages 20 are positioned at the first end 2 of the female terminal 1 in a radially internal position with respect to the first and second seatings 8, 9 of the first body 7. A coupling ball bearing 21 is positioned in each of the radial passages 20. Each of the radial passages 20 is slightly conical and tapered towards the main axis X-X and/or exhibits an edge at the radially internal surface, so as to impede the exit of the respective ball bearing 21 in a radially internal direction. The thickness of the wall of the second body 19 at the radial passages 20 is smaller than the diameter of the coupling ball bearings 21. Moving towards the second end 3 of the female terminal 1 , the second body 19 exhibits an annular recess 22 which exhibits two facing rest surfaces and houses the main spring 12. In particular, each of the opposite ends of the main spring 12 rests in part against one of the rest surfaces belonging to the first body and in part against one of the rest surfaces belonging to the second body 19. Moving further towards the second end 3 of the female terminal 1 , the second body 19 externally exhibits a radial narrowing which delimits a second endrun surface 23 facing towards the second end 3 and facing the first endrun surface 13 belonging to the first body 7. Moving still further towards the second end 3 of the female terminal 1 , the second body 19 exhibits a mechanical endun abutment "BM" facing towards the second end 3. Moving still further towards the second end 3 of the female terminal 1 , the second body 19 exhibits a radial seating 24 which houses a reference pin 25 described in detail in the following. Radial through-holes 26 radially cross the wall which defines the second body 19 and are located in an axial position corresponding to the position of the radial seating 24. Still moving towards the second end 3 of the female terminal 1 , the second body 19 exhibits a plurality of auxiliary radial passages 27 arranged along an annular pathway which lies in a radial plane, perpendicular to the main axis X-X. The radial auxiliary passages 27 open on a radially internal surface of the second body 19 to define a plurality of main housings 27a the function of which will become clear in the following. An auxiliary ball bearing 28 is positioned in each of the auxiliary radial passages 27. Each of the auxiliary radial passages 27 is slightly conical and tapered towards the main axis X-X and/or exhibits an edge at the radially internal surface, so as to prevent exit of the respective ball bearing 28 in a radially internal direction. The radially internal surface of the second body 19 exhibits an annular relief which develops radially towards the main axis X-X and defines a third endrun surface 29 facing towards the first end 2 and an abutment surface 30 facing substantially towards the second end 3 and towards the main axis X-X, i.e. converging in an axial direction directed towards the second end 2. The annular relief is positioned axial!y between the radial passages 20 and the radial seating 24. Moving from the main housings 27a towards the second end 3 of the female terminal 1 , the radially internal surface of the second body 19 exhibits a secondary annular housing 31 the function of which will be made more clear in the following. An O-ring "0" is inserted in a suitable cavity (of the radially internal surface of the second body 19) axially located between the radial passages 20 and the third endrun surface 29.

The female terminal 1 comprises an obturator 32 mounted internally of the second body 19 and exhibiting a head 33 and a sta!k 34 coaxial to the main axis "X-X". The female terminal 1 further comprises (figures 8a and 8b) a guide element 35 for the obturator 32, which is formed by a central body 36 provided with an axial passage 37 for the stalk 34 of the obturator 33. Radial arms 38 developed radially externally from the central body 36 (in the non-!imiting embodiment the arms are three in number). A peripheral appendage 39 extends from each of the radially externa! end of each of the radial arms 38, which appendage 39 extends projectingly and, in a non-deformed position thereof, extends parallel to the main axis X-X on the opposite side with respect to the central body 36.

The guide element 35 further comprises a radially external ring 40 which connects together the radially external ends of the radial arms 38. Each of the peripheral appendages 39 is elastically yielding and/or connected elastically yieldingly to the respective radial arm 38, in such a way as to radially flex if subjected to loads typical of the functioning of the female terminal 1. Each of the peripheral appendages 39 bears on a free end thereof opposite the radial arm 38 a terminal engaging end 41 which develops, as a protuberance, radially externally. The terminal engaging end 41 is connected to the radially external surface of the respective peripheral appendage 39 by means of an inclined portion 42. The guide element 35 is installed together with the obturator 32 in the second body 19 between the abutment surface 30 and a stop ring 43 mounted in a special cavity fashioned in the internal surface of the second body 19 at the second end 3 of the female terminal 1. A first auxiliary spring 44 of a helical type is mounted between the head 33 of the obturator 32 and the radial arms 38 about the central body 36 and to the stalk 34 of the obturator 32. A second auxiliary spring 45 of a helical type is mounted between the radial arms 38 and the stop ring 43 and is arranged flanked to the peripheral appendages 39. The two auxiliary springs 44, 45 push the head of the obturator 32 against the abutment surface 30. The reference pin 25 exhibits a cavity 25a which houses one of the peripheral appendages 39 which slides across it.

The female terminal 1 further comprises a substantially tubular third body 46 which develops along the main axis X-X and is formed by a first half-part 46a and a substantially cylindrical second half-part 46b, coaxial, axially aligned and screwed one to another.

The third body 46 exhibits a single internal annular cavity which substantially develops over all the axial dimension thereof and is delimited at the opposite axial ends by an endrun portion 47 of the third body 46 which is located at the first end 2 of the female terminal 1 and develops radially towards the main axis X-X and by a further portion 48 of the third body 46 which is located at the second end 3 of the female terminal 1 and develops radially towards the main axis X-X. The two portions 47, 48 can be seen as partial base walls of the cylinder defined in the third body 46. The portion 47 of the third body 46 which is located at the first end 2 delimits a third endrun surface 49 and the portion 48 of the third body 46 which is located at the second end delimits a second rest surface 50. The third endrun surface 49 and the second rest surface 50 face one another.

The third body 46 is mounted about the first body 2 and the second body 9. !n greater detail, a radially internal surface of the third body 46 is in partial sliding contact with the radially external surface of the first body 7. The third body and the first body further delimit (where they are not in reciprocal contact) an annular chamber 51 which houses a helical spring 52. The annular chamber 51 is axially delimited by the second rest surface 50 and by the first rest surface 17 of the first body 7 which are reciprocally facing. The helical spring 52 is wound about the first body 7 and rests against the second rest surface 50 and the first rest surface 1 . A first portion of the first body 7 having a smaller diameter which terminates with the threaded portion 16 exiting axially from the third body 46 and defines the second end 3 of the female terminal 1. A portion of the first body 7 having a greater diameter exhibits the axial end 7c which faces the third endrun surface 49. An axial end 9a of the second body 19 is further partially facing the third endrun surface 49 while an opposite axial end 19b faces the second endrun surface 15. The functioning of the female terminal 1 described above and illustrated in the appended figures will now be described.

Figure A and figure 1 respectively represent the male terminal 100 and the female terminal 1 in the rest conditions before the connecting step is carried out and imagining that the female terminal 1 is fixed to a rigid piping by means of the threaded portion 16, while the male terminal 100 is fixed to a flexible piping by means of the second end thereof 103. Figure 1 shows that the peripheral appendages 39 of the guide element 35 are in the rest condition with the respective terminal engaging ends 41 inserted in the main housings 27a. The auxiliary ball bearings 28 lie partially in the auxiliary annular seating 32 of the first body 7 and in such conditions do not exert any pressure on the respective terminal engaging ends 41. The whole guide element 35 is pushed, due to the action of the second auxiliary spring 45, towards the mechanical endrun abutment BM while the obturator 32 is maintained in the closed position against the abutment surface 30 due to the action of the first auxiliary spring 44.

Figure 2 represents the male terminal 100 in a step of partial penetration in the female terminal 1 and, imagining that the male terminal 100 is in pressurized static conditions, the obturator 107 is in fact maintained and blocked in an advanced position with no possibility for the respective spring 108 to compress. By effect of the first partial penetration, the second body 19 is pushed backwards along the main axis X-X, performing a travel which brings the axial end 19b of the first body 7 against the second endrun surface 15. Contemporaneously and consequently it can be noted that the auxiliary ball bearings 28 are pushed to press on the terminal engaging ends 41 in such a way as to cause flexion towards the main axis X-X of the peripheral appendages 39. This flexion acts on each of the peripheral appendages 39, freeing each from the main housing 27a thereof, such that the guide element 35 is no longer mechanically blocked in position but free to slide axialiy, retreating along the main axis X-X.

Figure 2 also shows that together with the travel made by the second body 19, the crown of coupling ball bearings 21 , tasked with mechanically blocking the male terminal 100, is accommodated internally of the second annular seating 9, enabling the male terminal 00 to penetrate internally of the female terminal 1 up to when the two heads of the obturators 32, 107, entering into contact therewith, create a first complete retraction, enabled by the first auxiliary spring 44 of the head 33 of the obturator 32 of the female terminal 1 , determined by the presence of pressure behind the head of the obturator 107 of the male terminal 100.

Figure 3 shows the complete penetration of the male terminal 100 internal of the female terminal 1. This complete penetration causes the retraction of the whole guide element 35, which performs a travel such as to bring the terminal engaging element 41 to the secondary annular housing 31 also afforded internally of the second body 19. In this new position the appendages 39 of the guide element 35 are free to release the radially internal previous flexion so that the auxiliary ball bearings 28 no longer act on the terminal engaging ends 41 and the terminal engaging ends 41 insert, with a radial elastic return, into the annular secondary housing 31. The insertion is facilitated by the sliding of the inclined portion 42 of each terminal engaging end 41 on an entry (inclined surface) of the secondary annular housing 31.

Figure 4 shows the male terminal 100 and the female terminal 1 in release conditions and therefore the second body 19, by effect of the main spring 12, reverse-travels to enable perfect re-alignment between the second body 19 and the first body 7.

In these conditions it can be noted that the male terminal 100 is stably blocked in the female terminal 1 by effect of the crown of ball bearings 21 which have moved to the annular contrast surface 10 of the first body 7. An O-ring grips on the external surface of the male terminal 200, determining a hermetic seal, while the head of the obturator 107 of the male terminal 100, by effect of the pressure present in the male terminal 100, maintains the guide element 35 completely retracted along the main axis "X-X". In this condition, the joint between the two terminals 100, 1 is mechanically and hermetically complete, stable and permanent, but the passage of the fluid between the two conduits 106, 4 is still prevented by the presence of the pressure acting internally of the male terminal 100.

Figure 5 shows the effects that take place internally of the joint at the moment when the pressure is actuated and the fluid flow which moves from the female terminal 1 towards the male terminal 100.

Initially the pressurised fluid F, which enters through the second opening 6, fills all the chamber internally delimited by the second body 19 and in part (at the second opening 6) by the first body 7 and, through the through-holes 26 of the second body 19 and the through-holes 18 of the first body 7 which lie in mutual fluid communication, goes also to fill the annular chamber 51. The section area (perpendicular to the main axis "X-X") of the second annular chamber 51 is slightly greater with respect to the section area of the second body 19, so that the third body 46 in effect retains the second body 19 in a blocked position. Thus, by effect of the working pressure, the second body 19 is retained securely in the blocked mechanical position. Consequently to this effect the working pressure can act only and exclusively against the head of the obturator 107 of the male terminal 100 and, when the delivery pressure present in the female terminal 1 becomes greater with respect to the pressure present in the male terminal 100, the head of the obturator 107 of the male terminal 100 is retracted up to the point of maximum compression. Consequently, the whole guide element 35 advances up to the mechanical endrun abutment "BM" which corresponds to the maximum passage section of the fluid exactly in the join position of the two obturator heads 107, 32. In this position, the peripheral appendages 39 of the guide element 35 return into the original position thereof internally of the main housings 27a, which, having the edges resting against the terminal engaging means 41 , determine the positional stability thereof. This condition is of fundamental importance as, even when inverting the direction of the fluid, the two obturators 107, 32 will not be able to displace, and limit the passage section. It can also be noted that the two springs 108, 44 are completely compressed with no possibility of any reciprocal axial movement.

The disconnecting step can happen only and exclusively after the liquid flow has been halted internally of the conduit 106, 4, and the pressure has been brought close to values close to zero bar. In these conditions too the female terminal 1 of the invention of the rapid-fit connection stably maintains the mechanical and hermetic seal conditions thanks to the force exerted by the main spring 12.

Figure 6 shows that once the pressure has been unloaded and the flow internal of the conduit 106, 4 halted, simply by gripping the male terminal 100 and pulling it in the opening direction A with a force such as to compress the main spring 12 the effects as described in the following occur. The second auxiliary spring 45 compresses as there is no longer the resistance generated by the working pressure in the annular chamber 51. The male terminal 100 drags with it the second body 19, which displaces the crown of coupling ball bearings 21 to the first annular seating 8 where the coupling bail bearings 21 radially dilate and consequently free the grip with respect to the male terminal 100. Contemporaneously the head 33 of the obturator 32 of the female terminal 1 , pushed by the first auxiliary spring 44, acts against the obturator 107 of the male terminal 100 as if it were an extractor, Note that the auxiliary ball bearings 28 internally of the auxiliary annular seating 14 are at a position such as not to exert any pressure or flexion on the peripheral appendages 39. Figure 7 shows that during the distancing between the male terminal 00 and the female terminal 1 , by means of the natural release of all the springs present, the aligned and closed conditions of the obturators 107, 32 of each terminal 100, 1 are obtained. The last element to maintain the contact between the male terminal 100 and the female terminal 1 is the O-ring O such that loss of fluid is as contained as possible in the moment of transition of the disconnecting step.