SYSTEM FOR REFUELLING MOTOR VEHICLES

DESCRIPTION

The present invention relates to a releasable coupling for a gas distribution line of a system for refuelling motor vehicles.

As is well known, when the type of fuel dispensed is highly inflammable, it is necessary to equip the dispenser with special safety devices aimed at preventing uncontrolled fuel leaks in the event that the hose which supplies fuel to the tank of a vehicle is dragged off. This situation typically occurs when an absent-minded user inadvertently starts driving the vehicle again while the fuel dispensing hose is still connected to the tank of the vehicle.

Despite enabling a correct isolation of the supply line, the safety devices present on the market have a drawback in that due to the dragging effect they undergo permanent deformation and damage precluding their subsequent use.

The technical task that the present invention sets itself is thus to realize a releasable coupling for a gas distribution line of a system for refuelling motor vehicles which enables the aforementioned technical drawbacks of the prior art to be overcome. Within the scope of this technical task, one object of the invention is to realize a releasable coupling for a gas distribution line of a system for refuelling motor vehicles that can safely and effectively intervene without being damaged so as to be reusable.

The technical task, as well as these and other objects, according to the present invention, are achieved by realizing a releasable coupling for a gas distribution line of a system for refuelling motor vehicles, comprising a first half-part and a second half-part that are reciprocally engageable, characterized in that said first half-part comprises a longitudinal valve body having a shutter that is axialiy movable in contrast to and by action of an elastic element, a cylindrical sleeve that is threaded internally for fastening said first half-part to said second half-part, and an enclosing support of said sleeve keyed on said valve body, said sleeve being divided into a plurality of distinct and separate cylinder sectors that are oscillatable for the release of the second half-part, each sector subtending an angle no greater than 90°.

Preferably, the sectors are identical and there are six of them. This construction has in fact demonstrated to be an advantageous compromise between the need to assure the continuity of the thread so as to enable the two half-parts making up the coupling to be screwed together and the need to enable an oscillation of the sectors without reciprocal interference so as to release the two half-parts making up the coupling in the event of dragging.

Other features of the present invention are defined, moreover, in the subsequent claims.

Additional features and advantages of the invention will be more apparent from the description of a preferred but non-exclusive embodiment of the releasable coupling for a gas distribution line of a system for refuelling motor vehicles according to the invention, illustrated by way of non-restrictive example in the appended drawings, in which:

figure 1 shows an axial section view of the coupling in the release condition;

figure 2 shows an axial section view of the coupling in a retaining condition; figure 3 shows the sleeve with sectors; and

figure 4 shows the body enclosing the sleeve with sectors.

With reference to the aforementioned figures, there is shown a releasabie coupling for a gas distribution line of a system for refuelling motor vehicles indicated overall with the reference number 1 ,

The coupling comprises a first half-part 2 and a second half-part 3 that are reciprocally engageable.

The first half-part 2 comprises a longitudinal valve body 4 having a shutter 5 that is ax i ally movable in contrast to and by action of an elastic element 6, a sleeve 7 that is threaded internally for fastening the first half-part to the second half-part 3, and an enclosing support 8 for the sleeve 7.

The elastic element 6 is in particular a helical spring.

The enclosing support 8 comprises a cylindrical wall 9 having an internal base flange 10 and a plurality of internal radial protrusions 1 1 positioned at a distance from the base flange 1 0 and distributed along the internal perimeter of the cylindrical wall 9.

In particular, the protrusions 1 1 , identical to one another, are distributed in an equally angularly spaced manner along an internal perimeter circumference of the cylindrical wall 9 of the enclosing support 8.

The protrusions 1 1 have a flat surface 12 which extends in a plane perpendicular to the axis of the cylindrical wall 9 of the enclosing support 8, and a lateral surface 13 configured as a cylindrical sector coaxial with the cylindrical wall 9 and provided with a recess 14 that extends for the entire angular extent of the lateral surface 13. The enclosing support 8 is keyed on the valve body 4 in a manner we shall see below i detail.

The sleeve 7, having a cylindrical configuration, is divided into a plurality of distinct and separate cylinder sectors 15 that are oscillatable for the release o the second half-part 3.

Each sector 1 5 subtends an angle no greater than 90°.

In particular, the sectors 15 are identical to one another and are provided in a number of six.

Each sector 15 thus has an angular amplitude of 60°.

The sleeve 7 has an internal thread 16 in an apical portion thereof and in a base portion thereof has feet 17 interposed between the radial protrusions 1 1.

The sleeve 7 projects out from the cylindrical wall 9 of the enclosing support 8 in an axial direction, at least for the entire axial extension of the apical threaded portion thereof.

The sleeve 7 further has an inner shoulder 18, which separates the base portion, where the feet 17 are present, from the apical portion having a larger inner diameter where the thread 16 is present.

In order to key the enclosing support 8 on the valve body 4 so as to prevent axial sliding, there is provided a locking ring 28 keyed fixedly onto the valve body 4 and interfering with the base flange 1 0, and an external shoulder 27 of the valve body 4 interfering with the inner shoulder 1 8 of the sleeve 7.

The base portion of the sleeve 7 has an inner cone-shaped lateral tapered delimiting surface, whereas the inner shoulder 1 8 of the sleeve 7 has a bevelled edge. The taper of the base portion of the sleeve 7 and the bevelled edge of the inner shoulder 18 of the sleeve 7 serve to facilitate the oscillation of the sectors 16, as we shall see.

The feet 17 have an external lateral delimiting surface lying along the external cylindrical generatrices of the sleeve 7 and an internal lateral delimiting surface lying along the internal conical generatrices of the base portion of the sleeve 7. Each foot 17 is made up of adjacent half-parts 1 7a, 1 7a provided at the base of two adjacent sectors 15.

Each sector 15 therefore has, at the sides of the base, two spaced half-parts 1 7a, each matching a half-part 17a of an adjacent sector 15 so as to form a foot 17.

The delimiting wall 29 of the top of the space present between the two half-parts 17a of each foot 17 rests upon the surface 12 of a corresponding protrusion 1 1 of the enclosing body 8.

On their internal lateral delimiting surface, the feet 17 have a groove 19 aligned with the recess 14 o the lateral surface 13 of the protrusions 1 1 .

A ring 20 for blocking axial slipping of the sleeve 7 off the enclosing support 8 is inserted in the grooves 19 and recesses 14.

The enclosing body 8 is housed in a guide bushing 21 which has an axial extent such as to entirely contain within it the assembly made up of the enclosing support 8 and the sleeve 7 positioned therein, and in particular the end of the apical portion of the sleeve 7 is positioned rearward relative to the apical end of the guide bushing 21.

Together with the sleeve 7, the guide bushing 21 delimits an annular cavity 23 into which a tubular engagement element 24 provided on the second half-part 3 of the coupling 1 can be introduced.

The guide bushing 21 is in turn entirely housed in a supporting receptacle 22 keyed on the valve body 4.

In particular, the guide bushing 21 has an inner shoulder 25 interfering with an external shoulder 26 of the enclosing body 8, which secures it against the bottom of the supporting receptacle 22.

The second half-part 3 comprises a longitudinal valve body 30, which externally supports the tubular element 24 so as to be axia!ly movable in contrast to and by action of an elastic element 34 consisting, in particular, of a helical spring.

The valve body 30 has an external thread 31 for engagement with the sleeve 7 and a shutter 32 that is axial ly movable in contrast to and by action of an elastic element 33 consisting, in particular, of a helical spring.

The elastic element 34 is positioned in an annular cavity 35 defined between the tubular element 24 and the valve body 30 and has one end interfering with a locking ring 36 fixed along the inner perimeter of the tubular element 24 and one end interfering with a locking ring 37 fixed along the outer perimeter of the valve body 30.

The tubular element 24 has a covering element 40 that covers it up to a rearward position relative to the head end thereof.

The tubular element 24 is further provided, at a base flange 39 thereof, with special pull rods 38 for the actuation thereof.

The joining of the two half-parts 2, 3 of the coupling 1 takes place in the following manner.

Initially, when the half-parts 2 and 3 are separate, the shutters 5 and 32, respectively, as a result of the action of the elastic elements 6 and 33, respectively, are in a position of closing the valve bodies 4 and 30, respectively.

As a result of an action on the pull rods 38, the tubular element 24 is made to translate until exposing the thread 31 of the valve body 30, which can thus be screwed into the sleeve 7. In this phase the elastic element 34 is loaded.

While the valve body 30 is being screwed into sleeve 7, the head of a stem 41 integral with the valve body 4 intercepts the shutter 32, exerting upon it a thrust that overcomes the reaction of the elastic element 33 : the shutter 32 is thus made to move rearward, with a consequent opening of the valve body 30.

At the same time a cup 42 integral with the valve body 32 intercepts the shutter 5, exerting upon it a thrust that overcomes the reaction of the elastic element 6: the shutter 5 is thus made to move rearward, with a consequent opening of the valve body 4. The cup 42 is sealingly connected with the shutter 5 by means of a sealing gasket 44.

The rearward movement of the shutters 5 and 32 ultimately determines the opening of the passage of fuel between the two half-parts 2 and 3 of the coupling 1.

When the pull rods38 are released, the exposed head of the tubular element 24 is inserted into the cavity 23 as a result of the thrust exerted by the elastic element 34, which is unloaded.

The travel of the tubular element 24 stops when the end of the covering head 40 is intercepted by the head end of the bushing 21 . In the event of a pulling force beyond a certain threshold, the coupling 1 enables a safe disconnection between the two half-parts 2 and 3 thereof, since the sectors 15 undergo an oscillation that determines a radial expansion of the threaded head portion of the sleeve 7 and the consequent disengagement of the thread 31 of the valve body 30 from the thread of the sleeve 7.

The fulcrum of oscillation of the sectors 15 relative to the valve body 4 is substantially provided by the external shoulder 27 of the valve body 4 on which the inner shoulder 18 of the individual sectors 15 rotates. This rotation is made possible thanks both to the bevelled edge of the inner shoulder 18 of the individual sectors 15, which avoids jamming, and the internal lateral surface delimiting the base portion of the individual sectors 15, which, having a cone-shaped taper 45 as noted above, does not interfere with the external lateral surface of the valve body 4 during rotation of the individual sectors 15.

The preferred application envisages liquid propane gas as the gas of the system for refuelling motor vehicles.

The coupling thus conceived is susceptible of numerous modifications and variants, all falling within the scope of the inventive concept; moreover, all the details may be replaced with other technically equivalent ones.

In practice, all of the materials used, as well as the dimensions, can be any whatsoever according to need and the state of the art.