Note: Descriptions are shown in the official language in which they were submitted.
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De~cription of the invention
The present invention relates to a quick coupling
for the di~tribution of fluids under presRure, consisting
of a union for the connection of a pipe, for the supply
of the fluid, and of an opening which can be shut off for
the introduction of a union for delivery of the fluid to
a user, there being provided inside the quick coupling a
fixed stem with a valve head forming a valve seat
together with tubular means which can be moved against
the action of spring means.
Quick couplings for fluids under pressure are
known, in particular quick couplings of the type with a
plane face which allow the end of the stem which faces
the inlet of the fluid under pressure and is equipped
with an external thread to be screwed into an axial
through-hole which is made in the body of the coupling.
The threaded end of the stem, which projects from
the axial hole of the support body, has to be provided
with a notch which serves lock the stem during locking of
a counternut screwed onto the free end of the stem.
This counternut is necessary in order to prevent
undesirable unscrewing of the stem -in relation to the
body of the coupling.
The body of the coupling, which is made in a
single piece, has a plurality of through-holes to define
passages for the fluid under pressure.
Rnown rapid couplings have the disadvantages that
their monolithic body is difficult to produce as far as
its mach;n;ng is concerned, given that the body has to be
equipped with a threaded axial hole and also with a
plurality of through-holes arranged in a wall and around
the axial hole.
The presence of individual through-holes brings
about an undesirable throttling of the passage for the
fluid under pressure. A further disadvantage of known
quick couplings is that the assembly of the coupling by
means of screwing and unscrewing the stem in relation to
the monobloc body is complicated and wastes a
considerable amount of time.
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Further~ore, the risk of undesirable unscrewing
of the stem in relation to the monobloc, in ca~es where
the counternut is not screwed firmly onto the stem, can
lead to disruptionR in the functioning of the quick
coupling to the extent that there i5 a risk of breakage,
causing damage as a result of the e~cape of oil under
pressure.
The aim of the present invention is to produce a
new quick coupling which does not have the disadvantages
of the prior art and which is easy to manufacture and to
assemble rapidly.
This aim is achieved with a quick coupling for
fluids under pressure having a union for the connection
of a pipe, for supply of the fluid, and an opening which
can be shut off for the introduction of a tubular union
- for delivery of the fluid to a user, there being~provided
inside the quick coupling a fixed stem having a valve
head which interacts with the valve seat formed by
tubular means which can be moved against the action of
spring means, characterized in that the end of the stem
which faces the inlet of the fluid under pressure haQ a
circumferential groove which receives with geometrical
mating a support disc consisting of two half-bodies which
can be asRembled and which have a central seat which
surrounds the stem in the region of the circumferential
groove, in that each half-body has at least one passage
opening for the fluid under pressure supplied, and in
that the ass~bled support disc is inserted and loc~ed
locally in a seat made in the body of the quick coupling.
The quick coupling for fluids under pressure
produced according to the invention has the advantages
that the stem is no longer ass~mhled with the body of the
quick coupling by means of a thread, as known from the
state of the art, but the stem is held fixed in position
by a geometrical mating between a support disc and the
stem and the body of the coupling. This geometrical
mating allows easy and rapid assembly of the new quick
coupling.
Therefore, the quick coupling, by virtue of its
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new and simple structure which is proposed according to
the invention, can be produced with a considerable time
saving as far as both its manufacture and its assembly
are concerned.
In a preferred embodiment, each half-body has a
through-opening which is advantageously arc-shaped.
For example, the ~upport disc has only two arc-
shaped holes which allow a considerable reduction in the
flow re~istance and therefore optimization of the passage
of the fluid under pressure without the formation of
undesirable vortices.
The opening made in the half-body is
advantageously in the shape of an arc arranged along a
semi-circle.
The end of the stem which faces the inlet of the
fluid is preferably in the shape of a hemisphere.
Such an aerodynamic shape of the end of the stem
allows an unimpeded and linear flow of the fluid under
pressure through the passage duct towards the inlet of
the fluid under pressure.
As an alternative, the end of the stem which
faces the inlet of the fluid can also have a parabolic
shape.
The half-bodies are advantageously made by means
of a sintering process.
This allows rapid mass-production of the support
discs at reduced costs.
As an alternative, the half-bodies can also
consist of bodies which are die-cast and/or composed of
synthetic material.
The object designed according to the present
invention will now be described in greater detail by
means of an embodiment given only by way of example and
illustrated in the attached drawings, in which:
Figure 1 shows the assembled quick coupling,
Figure 2 shows the quick coupling according to Figure 1
a~sembled and illustrated in section,
Figures 3 to 5 show in a lateral view the stages of
assembly of the quick coupling,
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Figures 6 to 8 ~how in a front view the ~tages of
a~embly of the quick coupling.
As i~ illustrated in Figures 1 and 2, the quick
coupling, indicated a~ a whole by 1, has an inlet union
2, in this case in the form of a hexagonal nut, and a
ring 4 which is rotatable in relation to the union 2.
A tubular element 3 is provided, screwed onto the
union 2, as is known from the prior art.
The inlet union 2 is connected to a pipe 6 which
0 i8 illustrated in Figure 2 in dot/dash lines.
The pipe serves to supply a fluid under pressure
which passes from the pipe 6 towards a passage duct 7 of
the quick coupling 1.
The quick coupling 1, which is formed in a
symmetrical m~ner in relation to the working axis 5, has
an opening bush 8 and a support body 9 on the inside.
These elements can be moved against the force of a ~pring
means 26, in this case a helical spring.
The bush 8 and the body 9 receive on the inside
a fixed stem 10 which serves as a means of shutting off
the flow. The bush 8 has a valve seat and interacts with
the valve head of the stem 10. The bush 8 is capable of
opening and closing the passage duct 7 for the fluid in
the region of the outlet of the quick coupling 1.
According to the invention, a support disc 11 is
arranged between the stem 10 and the body 9 by means of
geometrical mating. The disc 11 consists of two half-
bodies 12 shaped like small plates. ~ach half-body 12 has
a passage opening 25 (see Figure 6). The assembled
support disc 11 defines a central seat, with which the
disc 11 can be accommodated in a circumferential groove
13 provided at the end of the stem 10. At the same time,
the disc 11 is accommodated and restrained locally in a
seat 30 which is made in the body 9 of the quick coupling
1. The two half-bodies 12 serve as a means of support for
the stem 10 and are, with the seat 31, accommodated in
the circumferential groove 13 of the stem 10.
The body 9 is held ~against the thrust force of
the spring 26) in a rest position (see Figure 2 and 3) by
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means of the interaction of the bearing surfaces 14, 15,
16, 17 of the support disc 11 in relation to
counter~urface~ 18, 19, 20, 21 of the ~tem 10, of the
body 9 and of the inlet union 2.
Figure~ 1 and 2 illustrate that the union 2 is
screwed onto the body 9.
The stem 10 has, at its end 22 which faces the
inlet of the fluid, a hemispherical or parabolic shape,
forming a gradual guide surface for the fluid under
pressure. The circumferential groove 13 of the stem 10 is
located close to the end 22 of the stem 10. The quick
coupling 1 receives an auxiliary bush 23 which defines a
plane face and which can be moved towards the inside of
the quick coupling 1, that is to say against the thrust
force of the spring means 24 interposed between the
auxiliary bush 23 and the inlet union 2.
It can be seen from Figures 3, 4 and 6, 7 that
the half-bodies 12 are inserted into the y-oove 13 of the
stem 10. The body 9 is moved against the thrust force of
the spring 26 by an auxiliary means (not shown).
Figures 5 and 8 show the assembled half-bodies 12
holding the body 9 in a rest position against the thrust
force of the spring 26. The half-bodies 12 are provided
with an arc-shaped opening 25 which coincides with the
section of the passage duct 7 for the fluid under
pressure.
Therefore, the quick coupling 1, designed
according to the invention, can be pre-assembled (Figure
5) and sub~eguently assembled fully (Figure 2).
When the quick coupling 1 is connected to an
external pipe 6 provided for supplying the fluid under
pressure, the quick coupling 1 i closed in a sealed
manner, as illustrated in Figure 2. By means of the
introduction of a union for delivery of the fluid to a
user (not shown), a thrust force will be transmitted to
the auxiliary bush 23, in the direction of the arrows in
Figure 1 and 2, thus bringing about a movement of the
bush 23 towards the opening bush 8, and against the
thrust force of the spring-24. The quick coupling 1 still
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r~;n~ closed. At the ~ ^nt when the auxiliary bush 23
comes into contact with the opening bush 8, the external
thrust force causes a simultaneou~ movement of the bushes
23 and 8 against the thrust forces exerted by the spring~
24 and 26.
With the movement of the opening bush 8, the
fluid under pressure begins to pass through the duct 7
and through the outlet to the external user. When the
external thrust force iB removed, the bushes 23 and 8
return automatically, as a result of the thrust forces of
the springs 24 and 26, into the closing position of the
quick coupling 1, as illustrated in Figure 2.
The presence of the support disc 11 with the arc-
shaped openings 25 and the special ~hape of the end 22 of
the stem 10 optimize~ the passage of the fluid under
pressure through the quick coupling 1 from the point of
view of fluid dynamics.
According to the in~ention, the end 22 of the
stem 10 can also ha~e other aerodynamic shape~, for
example a parabolic shape.
The half-bodies 12 are preferably manufactured by
a sintering or casting process. Half-bodies made of
~ynthetic material can also be used.
