WO1985001565A1

WO1985001565A1 - Connector for plastic tubes

Info

Publication number: WO1985001565A1
Application number: PCT/FR1984/000208
Authority: WO
Inventors: André Legris
Original assignee: Société Legris
Priority date: 1983-10-03
Filing date: 1984-09-25
Publication date: 1985-04-11
Also published as: IT8467977A1; EP0158658A1; ES290731U; FR2552852A1; IT1179136B; IT8467977A0; ES290731Y; IT8453883V0; FR2552852B1

Abstract

Connector for plastic tubes conveying a compressed fluid, wherein the tube is instantaneously mounted by simply pushing means which make the tube undisconnectable. The female means of the instantaneous connector (1, 9) comprises a cylindrical guiding male part (1k, 9k), and the tubular male member (9) of semi-flexible plastic material comprises a circular recess (3h) of which the cylindrical surface is conformed with a small tolerance to the cylindrical guiding male part (1k), thereby forming a metal guiding support absorbing the lateral stress which might be exerted on the tubular male member. The invention is used for the connection of compressed air brake circuits.

Description

Connection device for plastic tubes

The object of the present invention is a connection device for plastic tubes comprising instant connection means.

This type of connection comprises means which make it possible to mount a tube or a connection accessory in an instantaneous connection by a simple push-on on the tube or the accessory without any other maneuver and so that the tube is held in the fitting and that sealing is ensured. These instant fittings are well known and have been the subject of French patents 2,012,796, 2,319,833, 2,258-585 and 2,749. which belong to the depositor. These fittings are widely used in industry for the connection of plastic pipes on machines operating with compressed air. Furthermore, the braking of the trucks is carried out by means actuated by compressed air and currently all the old circuits in steel tube are replaced by circuits in plastic tube of the polyamide type with high characteristics. Due to the fact that these plastic tubes are used which save weight, it has become necessary to save time during the assembly of the very large connections of the braking installation which is complex. Furthermore, it must be taken into account that braking safety is essential on trucks and that a braking fault presents a great danger on these vehicles. It is for these reasons that high security instant fittings have been specially developed for the braking system of trucks and the present invention relates to this type of fittings.

One-touch fittings of the known type do not meet the conditions required for their use in braking circuits for trucks, because they imperceptibly scratch the tube made of las i _{c material} . perfectly smooth and cause extremely small leaks, but unacceptable for this type of use.

The instant disassembly of a special circuit for braking, excessively increasing the price of the connection device, the following technique is adopted by the manufacturers of motor vehicles.

1) Instant mounting of the tubes and connecting elements on the assembly line.

2) Disassembly impossible or requiring unscrewing of the fitting itself from the device; the tubes and accessories remaining non-removable on the plastic tubes.

The present invention relates to a connecting device for plastic tubes conveying a compressed fluid and in which the tube is instantly mounted by a simple push in means making the tube non-removable.

The connection device is made up of connection accessories provided with at least one female instantaneous connection means and at least one tubular male member, said accessories being combined with mounting members on a device comprising a female instant connection means.

In accordance with the present invention, the female instantaneous connection means comprises a male part, of cylindrical guide, and the tubular male member of semi-flexible plastic material comprises a circular recess, the cylindrical surface of which conforms with a small clearance, the male guide part. cylindrical thus constituting a metal support guide absor¬ bant the lateral forces likely to be exerted on the male tubular member.

The device according to the invention makes it possible to obtain a connection having total security of the resistance of the tubular male member due to the metallic guide support and the absorption of forces.

O PI lateral on the tubular male member which allow to obtain a reliable product and not risking rupture.

This cylindrical guide arrangement on the tubular male members and on the female instant connection means is found both on the device mounting members or cartridges and on the connection accessories, so that it is very easy to mount a connection accessory on another accessory by fitting a male member into a female member with a support guide according to 1'in¬ vention.

In order to obtain this metallic support of the tubular male organ in plastic material, it is pre¬ seen that the fitting depths of the tubular male organ have a length exactly adapted to the depth of the cartridge and to the instant fittings fe ¬ of different accessories. From this mantle, one can mount a tube or an accessory to a tubular male member, the depth being the same in the instant female connector.

It follows that the tube and the tubular male member are fitted and held over the entire axial length of the cartridge and that the instantaneous connection means either of the cartridge or of the accessories are housed and limited by flat bottom housing which corresponds to an important characteristic of the invention.

Indeed, unlike French patent n ° 2.319.833 which reserves an important guide of the tube in the device on which the device is implanted, requiring so much special housing and a significant depth, the device according to the invention includes a guide of the tube and of the male member in the cartridge or the accessory per¬ putting the use of short housings, easy to accommodate, with flat bottom, simple to carry out in all the apparatuses and using standardized housings tapped smooth teeth.

The cartridge forms a short and compact, simple assembly which can be screwed, crimped or fitted, the tube or the tubular male member of which does not protrude from the clamp constituting one of the members of the instantaneous connection means.

The invention, more particularly intended for the compressed air braking device, is not limited to this use and can also be suitable for all medium-pressure fluid circuits which is limited by the resistance of the plastic tubes.

Other characteristics and advantages of the invention will be better understood on reading the following description of several embodiments and with reference to the appended drawings in which: FIG. 1 is a view in elevation and in section axial view of an embodiment of the connection device according to the invention. Figure 2 is the same view as in Figure 1, the cartridge being separated from the accessory. Figure 3 is an axial sectional view of a cartridge mounted on an apparatus. Figure 4 is an axial sectional view of a cartridge in the disassembled state. Figure 5 is an axial sectional view of a cartridge in which is mounted a tube provided with a fur. FIG. 6 is a view in elevation and in axial section of another embodiment of a connection device. Figure 7 is an axial sectional view of a cartridge with another cylindrical guide mode. Figure 8 is an elevational view in axial section of an assembly of several raσ cording accessories. Figure 9 is an elevational view in axial section of an accessory comprising an orga_na_aιale consisting of a plastic tube element. Figure 10 is an elevational view in axial section of the accessory of Figure 9 mounted in a cartridge. Figure 11 is an elevational view in axial section of the connection device in which the sleeve is crimped into the body of the accessory. Figure 12 is an axial ααupe view of a connection device in which the cartridge is crimped on the device. Figure 13 is an axial sectional view of the cartridge shown in Figure 12. Figure 14 is a sectional view of a connection device in which the instantaneous connection clamps are made of cut sheet metal. Figures 15 to 17 are views in axial section of cartridges having clamps in sheet metal décou¬ pée. Figures 18 to 21 are external elevation views of several embodiments of accessories.

In Figures 1, 2, 3 and 4 there is shown an embodiment of a connection device according to the invention which is mounted on an apparatus 2 having a tapped hole 2a of shallow depth, delimited by a flat bottom 2b and in which is screwed a cartridge 1 by its threaded portion lf with the interposition of an O-ring seal le.

The cartridge 1 has internally a cylindrical bore lm (Fig. 3) in which is provided a groove receiving an O-ring seal 1b, said bore being extended by a double conical part In, and a bore lo in which is housed a clamp deformable split 6 comprising one or more hooking teeth 6a and a washer held therein by a 1-1 crimped edge of the cartridge, limiting and retaining the clamp 6 which has an unsplit part 6b of the same diameter as the 1 m bore.

On the cartridge 1 is mounted an accessory in the form of a connection angle 3 comprising a tubular male member 4 of semi-flexible plastic material engaged in the cartridge 1 (Fig.l).

The tubular male member 4 is mounted in the body 3f of the accessory by means of its flange 4a which is retained by a metallic piece 3b in the form of a cup engaged in a circular housing of the body 3f and locked therein. by means of a crimped edge 3c, a seal 3a being disposed between the collar 4a ^" of the male member and the housing of the body 3f receiving said collar. The tubular male member 4 has a hazard 4b, which opens into an inner conduit 3n of the body 3f of the accessory, said conduit 3n itself opening at its other end into a socket 9 which has a threaded portion 9b screwed into a tapped hole 3d, with a flat bottom 3e, with interposition a sealing O-ring 9a.

The socket 9 has internally the same shape as the cartridge 1 and receives like this a seal 1b and a clamp 6. In the socket 9 is mounted the end of a tube 5 of semi-flexible plastic which is hung by the tooth 6a of the pliers 6.

Furthermore, the bracket accessory 3 is held by its tubular male member 4 which is engaged and hung in the clamp 6 housed in the cartridge 1, said accessory thus being secured permanently and cannot be dismantled with the cartridge 1 and the tube 5.

The accessory 3 can be rotated 360 ° around the axis of the cartridge 1.

The disassembly of the connection means can only be carried out by unscrewing the cartridge (the mon¬ tage being rotary) from the body 2 by its collar Ih which

* \ 3R £ Xξ- ~. presents externally .the shape of a hexagon.

The tubular member 4 being made of semi-flexible plas¬ tic material to allow it to hold on to the clamp 6, it therefore has limited resistance and could not in the long term withstand significant lateral forces which would be produced by trac¬ tions or other untimely efforts exerted on the tube 5.

The main characteristic of the invention therefore resides in the fact of providing a resistant metal support means absorbing the lateral forces.

This result is obtained by providing on the cartridge 1 in the collar lh a circular recess lg delimiting a male cylindrical guide part lk which is in contact with the cylindrical surface 3h of the cup 3b surrounding the tubular male member 4 at its base.

In this way the cylindrical surface 3h matches the male guide part lk with little play.

The circular recess lg, on the cartridge 1, saves the maximum space (Fig. 3) so as to obtain a cartridge 1 very slightly protruding from the device 2 and a square accessory 3 having the smallest possible height .

As a result, the cartridge 1 can be placed in a tapped hole 2a of standard or short depth, limited by a flat bottom, that the sleeve 9 is also in a shallow 3d tapped hole limited by a bottom 3e and that the tube 5 and the male member 4 are engaged at the same depth "l" providing a standard depth rating for the same nominal diameter.

The diameter of the tube 5 is exactly equal to the diameter of the male member 4 and they are capable of being engaged in the same ins¬ tantane connection means. The tube 5 or the male member 4 do not exceed the cartridge 1 or the sleeve 9 and occupy the entire length "î". In the cartridge 1, it is possible to mount either directly a tube 5, or a male member 4, so that it is possible to mount in the said cartridge any accessory of any shape. For this purpose the diameters of the parts 3h, lk, and 9k, are identical to the mounting tolerances and constitute guide means.

In Figure 5 there is shown a cartridge 1 mounted on a device 2 and in which is engaged the end of a tube 5 whose central part is soute¬ naked against creep by a fur 7 consisting of a tu be metallic in very thin sheet metal. The fur 7 makes it possible to considerably improve the heat resistance and in the long term, by eliminating the creep of the tube 5 in plastic material at the level of the tooth 6a, of the clamp and at the tightening of the joint 1b; it is essential for the truck braking system activated by compressed air.

The useful depth of the cartridge is equal to "i ⁿ c *, that is to say almost all of its length.

Figures 6 and 7 show a variant embodiment of Figure 1 in which the circular recess lg, has been eliminated e in which the male part of cylindrical guide lk lk protrudes completely above the flange lh.

Furthermore, the tubular male member 4 is held by a simple washer 8 by an edge of the body 3f. Of the accessory 3. The metallic cylindrical guide surface 3h is produced by the body 3f which is itself made of metal. The sleeve 9 is elongated to have the same depth as the cartridge 1 which in this case is a little longer than in the previous example and it protrudes a little more from the device 2 (Fig. 6). In this case, the socket 9 and the cartridge 1 have a length! ** greater than the length "V * of the previous embodiment. In Figure 8, there is shown an assembly of an accessory 3 bis identical to the accessory 3 and which comprises a male -tubular member 4 made of plastic which is engaged in the socket 9 of the accessory 3. The assembly can because the depths "l" are identical and the diameter of the male member 4 is the same as that of the socket 9.

Therefore any male-female accessory can receive any accessory of the same diameter with the guide means 9k.

In FIGS. 9 and 10 a variant of FIG. 2 is shown in which the male tubular member 4 made of molded plastic material has been replaced by an element 5a cut from a tube 5 and on which a ring is crimped. 10 with thin lips. The element of the tube 5a is supported over its entire internal diameter by a thin metallic fur 7a. The tube element 5a and its fur 10 are mounted as in FIG. 2.

The advantage lies in the fact that for the male member 5a, the same tube 5 as for the canalizations.

In Figure 11 there is shown a varian¬ te of Figure 1 in which the sleeve 9 is not vis¬ sée on the body 3f of the accessory as before, - but it is simply fitted into a cylindrical housing 3m and held by a crimped edge 3i formed on the body 3f. The disassembly of the connection device being carried out by unscrewing the cartridge 1 from the device 2.

Figure 12 shows an alternative embodiment of Figure 11 in which not only the sleeve 9 is fixed by crimping but also the car¬ key 1 which is screwed in the previous embodiments.

For this purpose, the cartridge 1 is engaged in a cylindrical housing 2m and it is retained by a crimped edge 2p formed on the device. The device is no longer removable or repairable and the cartridge is smaller due to the fact that the collar delimited by a hexagon is removed.

The crimp cartridge 1 shown alone in Figure 13 does not have a hexagon, but a lp gor¬ ge intended for crimping and its etanσhëité joint, is disposed in another groove.

The crimp cartridge is almost identical to the socket 9, but it additionally comprises the round U le, which maintains the retention of the pliers and which is used as a stop for the tube.

In Figure 14 there is shown a varian¬ te of Figure 1 in which the metal clamp-bar and milled or molded is replaced by a holding piece or clamp in cut sheet metal 11, having legs d ^r snap elastic 11a, fixing tabs 11b, and stop tabs 11c, said clamp 11 being held in the cartridge 1 by a crimped edge 12 which allows it to rotate along the axis of the cartridge. The hooking lugs lia have the characteristic of allowing the tube to be hooked in a non-removable manner. The same pin 11 is mounted in the cartridge 1 and the socket 9 which, as before, have the guide means lk, 3h 9k. FIG. 15 shows the cartridge alone provided with a clip 11 made of cut sheet metal with its hooking tab 11a, its holding tabs 11b, and its tube stop tab 5.

FIG. 16 shows a variant of the clamp 11 which is produced in two parts, the holding part 1 with the latching lugs 12a and the washer already used in FIGS. 1 and 16.

In FIG. 17, a variant of FIG. 16 is shown, in which the washer 1c has been removed and the sheet metal clamp 13 for holding is disposed in a groove ls, of the cartridge, said clamp 13 comprising 13c stop tabs of the tube. The clamp 13 is mounted by elasticity because it is made of rolled sheet metal with a slot.

In Figures 18 to 21, there are shown non-limiting examples of mounting accessories, each of which must include at least one instan¬ taneous female inlet connection and at least one tubular male member made of semi-flexible plastic.

In the case of FIG. 18, which represents a straight accessory 14 with a female part 14a and a male part 14b, we are in the presence of a male-female union connection if the diameters 14a, 14b are equal, of a reduction if the diameter 14a is smaller than 14b, and a magnification accessory if the diameter 14a is larger than 14b.

In Figure 20, there is shown an accessory Tee 15 whose straight parts 15a are femel¬ and having a male member 15b. The diameters of the three ends can be equal, two can be equal, or all three can be unequal.

In Figure 21, there is shown a tee fitting 16, the male and female ends of which are arranged differently.

The method which would consist in reversing the metallic support guide means, in which the cylindrical male part k is located on the tubular plastic male part and the female part 3h, on the female instant connection means, also remains in the field of the invention. The present invention finds its application especially in the ultra-fast assemblies of compressed air circuits for braking trucks, but it can also be used in all industries to economically establish fluid circuits for pressures ranging from vacuum to 20 bars, with quality plastic pipes. Of course, the invention is not limita _¬ tive and those skilled in the art can make modifications without departing from the scope of the invention.

Claims

1. Connection device for plastic tubes conveying a compressed fluid in which the tube is instantly mounted by a simple push in means making the tube non-removable, said device consisting of connection accessories provided with at least one female instantaneous connection means and at least one tubular male member, said accessories being combined with mounting members on an apparatus and comprising a female instantaneous connection means, characterized in that the female instantaneous connection means (1 , 9) has a male guide portion cylin¬ drique lk, 9k, and in that the tubular male member (4) of semi-flexible plastic material has a circular recess 3h, the cylindrical surface of which matches with a small clearance, the male part of cylindrical guide lk thus constituting a metal support guide absorbing the lateral forces liable to be exerted on the member tubular male.

2. Device for connection according to claim 1, characterized in that the mounting of the accessories on a device (2) is carried out by means of a car key (1) screwed into a tapped hole (2a) of the apparatus with the interposition of a seal (le), said cartridge containing a female instantaneous connection member occupying the entire length "j, ^" of the latter, said connection member comprising an elastic split clamp ( 6) provided with at least one row of hooking teeth (6a), an O-ring (lb) and a crimped washer (le), for holding the clamp and for the tube stop, said cartridge having a part male cylindrical guide (lk) formed from an annular housing (lg) in a flange (lh) of the cartridge delimited externally by a hexagon.

3. Connection device according to claims 1 and 2 characterized in that the mounting and connection accessories comprise a male member

WIPO tubular (4) protruding from the body of the accessory with a length "£" identical to the interior depth of a cartridge (1) or of a socket (9) mounted on the accessory, and containing a connecting member instantaneous.

4. Connection device according to the re¬ vendication 1, characterized in that the tubular male member (4) is fixed in a body (3f) of the accessory by means of a stamped cup (3b) which is crimped into the body (3f) delimiting an annular recess (3g) presenting a cylindrical guide surface (3h) of identical diameter, increased by a very small clearance, to that of the ^' cylindrical guide male part (lk , 9k).

5. Connection device according to claim 1 characterized in that the tubular male members (4) are made of semi-flexible plastic material of hardness substantially equal to that of the tube connections (5).

6. Connection device according to re¬ vendication 1 ,. characterized in that the tubular male member consists of a tube element made of plastic material (5) internally reinforced by a metallic fur (7a) consisting of a thin sheet, said tube element plastic material being provided at one of its ends with an annular retaining piece (10) crimped on said element.

7. Connection device according to re¬ vendications 1 and 3, characterized in that on the body (3f) is mounted by a screwed part with the interposition of a seal (9a), a socket (9) having a depth "i" identical to that of the cartridge (1), said sleeve containing a seal (lb) and a clamp (6) identical to those of the cartridge (1), said sleeve (9) having a flat bottom against which is sus¬ ceptible to come en.butée the clamp (6) and the tube (5), la¬ said sleeve (9) having a male cylindrical guide means (9k) for guiding the male organs tubu¬ laires (4), said guide (9k) having the same diameter than the cylindrical male part (lk) of the cartridge.

8. Connection device according to the re¬ vendication 1, characterized in that the accessories are capable of being mounted one on top of the other so

5 complementary and include male and female end pieces so as to obtain in particular an elbow, a male female union connector, a tee, a cross.

9. Connection device according to re¬ vendications 1 and 2, characterized in that the male cylindrical guide portion (lk) consists of a cylindrical prolongation extending beyond the delimited flange (lh) by a hexagon so that the cartridge has a length "l" greater than the length "Z".

10. Connection device according to re- vendication 1, characterized in that the male tubu¬ lar plastic part (4) is held in the body (3f) of the accessory by a washer (8) set in said body and in which the annular recess (3g) is made in the body of the metal fitting to form the guide surface (3h).

11. Connection device according to re¬ vendications 1 and 2, characterized in that the tapped hole (2a) into which the cartridge (1) is screwed onto the device (2) has a relatively short length and a flat bottom ( 2b) so that it is completely filled by the cartridge (1) and that the tube (5) does not protrude into the body (2) of the device.

12 .. Connection device according to rer .. „. vendication 1, characterized in that each instant connection means mounted in a member comprising a male cylindrical guide part (lk), (9k), is suscep¬ tible to selectively receive the end of a tube (5) or of a tubular male member (4) in the same depth "l".

13. Connection device according to re¬ vendications 1, 2 and 7, characterized in that the assembly of a tube (5) or of a tubular male member (4) in an instantaneous connection means is non-removable, the tube becoming integral with the cartridge (1) or in a fitting (3), the separation of the device from the piping being likely to be carried out by unscrewing the cartridge (1) of the device (2).

14. Connection device according to claims 1 and 7, characterized in that the sleeve (9) is mounted on the body (3f) of the accessory in a smooth housing (3m) with a flat bottom and held by an edge. crimped (3i) of the body (3f), said sleeve having a male cylindrical guide part (9k), and a length "j".

15. Connection device according to the re¬ vendication 1, characterized in that the cartridge (1) is mounted on the device (2) in a cylindrical housing

(2m) with flat bottom of shallow depth and maintained by a flange (2p) crimped in a groove (Ip) of the cartridge.

16. Connection device according to Reven¬ dication 1, characterized in that the attachment clip of the instantaneous connection means consists of a piece of cut sheet metal (11, 12, 13) comprising latching lugs multiple (lia, 12a, 13a) self-catching, la¬ said clamp being fixed in the cartridge (1) or the sleeve (9) by direct crimping, crimped washer, screwing the sleeve or groove in the cartridge.