WO1999027289A1

WO1999027289A1 - A liquid-tight joint between a flexible pipe and a coupling

Info

Publication number: WO1999027289A1
Application number: PCT/IT1998/000325
Authority: WO
Inventors: Luciano Cippitani
Original assignee: I.Co.M. S.R.L.
Priority date: 1997-11-24
Filing date: 1998-11-19
Publication date: 1999-06-03
Also published as: ITRM970726A3; ITRM970726A1; AU1259299A; IT1297779B1; ITRM970726A0

Abstract

This invention relates to a tight joint for flexible pipes (1) enabling the jointing of couplings (7) and pipes (1) when needed, without the need of special equipment, with the normal instruments and skills generally found in a workshop; according to this invention, the flexible pipe is secured to the partially tapered shank (8) of a nozzle (5), featuring a groove (6) and a rabbet (6a), by means of a doughnut ring (3) and a joint (2); the joint has a rabbet on the pipe-fitting end and is threaded on the opposite side, which threading engages the coupling fastened, for example, to a valve.

Description

A liquid-tight joint between a flexible pipe and a coupling

Technical field

This invention relates to a tight joint for flexible pipes, wherein the pipe

is secured to the partially tapered shank of a nozzle, also featuring a

groove and a rabbet, by means of a doughnut ring, which is introdeced

into the pipe and then pushed up against the rabbet of the nozzle, by

means of a joint with a hole for introducing the pipe, whose threaded end

engages a threaded coupling, while at the opposite end there is a rabbet for preventing the doughnut ring fro slipping out so that, by screwing

the joint to the coupling the doughnut ring forced between the rabbet of

both joint and nozzle reaches up to the groove. In this position, thanks to

the tapering of the nozzle shank, to the groove and the doughnut ring, the

pipe is squeezed against and tightly secured to the nozzle shank, thus

connecting the pipe, nozzle and coupling assembly, ensuring high

resistence and tightness and marking it suitable for use in equipment

crossed by high-pressure fluids, such as gas and water supply systems.

State of the art

It is well known that to connect the flexible pipe sections of a system

capable of withstanding very high pressures, such as a gas supply system,

screw-type couplings are generally used, for connecting two or more

sections of pipe or a pipe and a piece of equipment, or a valve, etc. ι

SUBSTITUTE S The joints between flexible pipes and couplings are generally secured by

means of clinching, using special equipment for stably and tightly joining

the coupling and the pipe.

Clinching, as also other means for tightly jointing couplings and pipes, tend to be very expensive, since it must be carried out in special

workshops or, alternatively, entails the purchase of special equipment.

Therefore, it is hardly suitable for cases where the lenght or type of pipe

changes each time, according to the use. A typical example is that of a workshop where LPG tanks are fitted on vehicles. In this case, th length

° of the flexible pipes connecting the system components chenge according

to the vehicle model, whereby the fitter would be required to store a

range of pipes for each vehicle model, at a considerable cost and with the

risk of not having the right pipe available when needed.

In the aforementioned situation, and in many other similar situations, the

5 only alternative to storing an expensive range of pipes is to purchase the

clinching equipment, but this too is an expensive remedy, which may

weigh heavily on the workshop's running costs.

Essential technical features

This invention relates to a tight joint for flexible pipes enabling the

0 jointing of couplings and pipes when needed, without the need of special

equipment, with the normal instruments and skills generally found in a

workshop.

According to this invention, the flexible pipe is secured to the partially

tapered shank of a nozzle, featuring a groove and a rabbet, by means of a doughnut ring and a joint. The joint rabbet on the pipe-fitting end and is threaded on the opposite side, which threading engages the coupling

fastened, for example, to a valve.

By screwing the joint to the coupling, for example a valve, the doughnut

ring surrounding the pipe is pushed up to the groove and the rabbet of

the pipe against the rabbet of the nozzle.

The tightness between the pipe and the nozzle is guaranteed by the

pressure exercised by the joint, when screwed, on the doughnut ring, and

by the latter against the pipe, by virtue of the tapered profile of both the

ring and of the nozzle shank. Brief description of drawings

A specific embodiment of the invention will now be described by way of

example with reference to the accompanying drawing in which:

Figure 1 shows an exploded cross-section of the joint components.

Figure 2 shows a cross-section of the assembled components.

Best mode for carrying out the invention

Referring to the drawing, the pipe (1) to be tightly jointed to the nozzle

(5) and the coupling (7) is introduced into the joint (2) and the doughnut

ring (3), whose external diameter is slightly smaller than the joint (2). The

joint (2) has a hole for introducing the pipe and, at the pipe-fitting end

there is a rabbet (4) for stopping the doughnut ring (3) inside the joint

(2). The tapered shank (8) of the nozzle (5) is introduced inside the pipe

(1), by hand and by applying a slight pressure, onto which the joint (2)

and the doughnut ring (3) have already been fitted. The joint (2) is threaded, which threading (2a) engages the threading (7b)

of the coupling (7). By screwing the joint (2) to the coupling (7) we obtain

by contrast, thanks to the rabbets (4) and (6a) on the joint (2) and the

nozzle (5), respectively, the introduction of the doughnut ring (3) onto the

pipe (1) is on tapered shank (8) of the nozzle (5).

The doughnut ring (3), whose tapering is consistent with that of the

tapered shnk of the nozzle (5) and which is fitted around the pipe (1), is

tightened around the pipe (I) by the joint (2) against the tapered shank

(8), until the pipe (1) and ring (3) assembly reaches the groove (6) and the rabbet (6a) at the opposite end of the tapered shank (8); in this position

the outside walls (5a) of the nozzle (5), which fit into the inside walls (7a)

of the coupling (7) are secured one against the other (see fig. 2) and the

pipe (1) is integral with the tapered shank (8) of the nozzle (5), squezeed

against it by the pressure exercised by the walls of the joint (2) against the doughnut ring (3) and by the pressure exercised, in turn, by the

doughnut ring (3) against the tapered shank (8) of the nozzle (5), thus

guaranteeing the absolute tightness of the pipe, nozzle and valve

assembly.

From the aforementioned description it is obvious that this tight joint

remedies the need of storing a wide range of pre-assembled pipes, since it

is extremely simple to fit this joint on sections of pipe cut to measure by

the fitter when needed, as well as having to incur the expense of the

clinching equipment. It is also obvious that, although the invention has been described

referring to the fitting of LPG tanks on vehicles, it may be adapted to any

other system requiring the same characteristics of tightness and

comprising a fluid circulating through flexible pipes at joints with

equipment or other sections of pipe.

Claims

CLAIMS 1- A tight joint between a flexible pipe and a coupling comprising: a cylinder joint (2), a pipe clamp (3), a nozzle (5) and a coupling (7), wherein the joint (2) has a hole at one end for introducing the pipe (1) and a rabbet (4) and is threaded at the other end (2a), the threading being separated from the rabbet (4) by a distance which a slightly exceeds the height of the ring (3); which ring (3) is slightly tapered and has the external diameter slightly smaller than the internal diameter of the joint (2a) and an internal diameter slightly larger than the pipe

(1); where the nozzle (5) has a tapered shank (8) which, at the opposite

end to tha end fitted inside the pipe, has a groove (6) and a rabbet

(6a); the walls of the nozzle (5) adjacent to the fluid outlet are angled so as to perfectly fit into the couplin (7a), when the joint (2) and coupling (7) assembly are screwed the one to the other (2a) and (7a),

respectively.

2- A tight joint between a flexible pipe and a coupling as claimed in

Claim 1, wherein the nozzle (5) with the groove (6) is fitted into the

pipe (1) by means of the tapering shank (8) and the two are secured by

means of the tapering ring (3), which after having been fitted to the

pipe (1) is pushed against the rabbets (6a) and (4) of the nozzle and the

joint, respectively, by means of the joint (2), whose threaded end (2a)

engages with the threading on the coupling ("'): by screwing the joint

(2) to the coupling (7), the doughnut ring (3) is pushed by the advance of the joint (2) until it reaches the groove (6) and the rabbet (6a) of the

nozzle (5).

- A tight joint between a flexible pipe and a coupling as claimed in the

preceding claims, wherein once the joint (2) and the coupling (7) have

been screwed and tightened, the angled external walls (5a) of the

nozzle (5) are tightly secured against the internal walls (7a) of the coupling (7) and the pipe (1) is integral with the tapered shank (8) of

the nozzle (5) and squeezed against it by means of the pressure

exercised by the walls of the joint (2) against the doughnut ring (3) and

by this against the tapered shank (8) of the nozzle (5), thus guaranteeing the tightness of the pipe (1), nozzle (5) and coupling (7)

assembly.

- A tight joint between a flexible pipe and a coupling as claimed in the preceding claims, wherein the pipe clamp (3) plays a key role in

guaranteeing the efficiency of the joint.