Flow distributor for fluid circuit and its application to shuttleless looms with pneumatic insertion of the weft

A flow distributor for a fluid circuit is especially applicable for use in a shuttleless loom with pneumatic insertion of the weft and comprises a body of revolution, produced from two parts assembled coaxially and forming therebetween an annular inner chamber defined by a conical wall and by a frusto-conical wall. The annular chamber connects a tubular mouthpiece for the inlet of fluid disposed on the central axis body with a plurality of outlet holes provided concentrically and at regular angular intervals around the central axis and able to receive screw-threaded couplings. This flow distributor is especially used for supplying compressed air to groups of relay nozzles on a shuttleless loom.

FIELD OF THE INVENTION 
The present invention relates to a flow distributor for a fluid, (pneumatic 
or hydraulic) circuit. This invention relates more particularly, though 
not exclusively, to shuttleless looms with pneumatic insertion of the 
weft. 
BACKGROUND OF THE INVENTION 
In this type of loom, the pneumatic system for insertion of the weft most 
frequently comprises an insertion nozzle, situated on one side of the 
loom, and numerous relay nozzles located along the axis of insertion, over 
the entire width of the loom. These relay nozzles, creating jets of air 
which complete the action of the insertion nozzle in order to pull and 
guide the weft thread until it reaches the other side of the machine, are 
distributed in groups each of N nozzles, each group of nozzles being 
supplied with compressed air by the same pneumatic pipe, the opening or 
closing of which is controlled by a solenoid valve actuated according to a 
predetermined sequence. Downstream of this solenoid valve, it is thus 
advisable to divide the flow of compressed air, corresponding to the 
consumption of all the relay nozzles of the group, into N partial flows, 
each of which will supply one of the relay nozzles of this group. 
For applications of this type, one presently uses flow distributors in the 
form of parallelepipedal units of relatively slight thickness, with a 
central or lateral compressed air inlet and with a certain number of 
substantially aligned outlet passages on one of the faces of the 
parallelepipedal unit. An arrangement of this type favors the central 
outlet passage or passages, at the expense of the terminal outlet 
passages, a "baffle" effect being produced in the path of the compressed 
air between the inlet and the terminal outlet passages. Thus, the partial 
flows in the various outlet passages are not all equal and differences are 
also ascertained between the outlet passages for the response time on use 
and possibly for the pressure. 
OBJECT OF THE INVENTION 
It is an object of the present invention to remedy these drawbacks by 
providing a flow distributor for a fluid circuit of new design, making it 
possible to obtain absolutely equal partial flows in all its outlet 
passages. 
SUMMARY OF THE INVENTION 
To this end, the flow distributor of the invention is constructed generally 
as a body of revolution with an annular inner chamber defined by two 
coaxial walls, one being conical and the other frustoconical, this annular 
chamber connecting a fluid inlet orifice, centered on the axis of the body 
and situated at one end of the latter, opposite the point of the conical 
wall, with a plurality of outlet passages distributed concentrically and 
at regular angular intervals all around the axis of the body, at its end 
remote from the central inlet orifice. 
It will be understood that this flow distributor, appearing externally as a 
unit with symmetry of revolution, with a fluid inlet along its axis and 
with N outlet passages distributed over a circle centered on its axis, the 
fluid passing through an annular chamber with conical and frustoconical 
walls ensuring homogeneous diffusion towards the outlet passages, makes it 
possible to supply all these outlet passages under absolutely identical 
conditions as regards flow and pressure. 
The fluid inlet orifice at one end of the body may be formed by a central 
tubular mouthpiece connected to the annular chamber. Preferably, a rounded 
transition area is provided for the connection of the cylindrical inner 
wall of this tubular mouthpiece to the frustoconical wall of the annular 
chamber, to promote an adhering effect of the fluid. 
For an easy construction of the flow distributor according to the invention 
with its annular inner chamber and the desired surface qualities, the body 
of this distributor advantageously results from the joining of two parts, 
machined separately then assembled coaxially for example by being fitted 
together, the first part comprising the central tubular mouthpiece as well 
as the outer frustoconical wall of the annular chamber, whereas the second 
part comprises the inner conical wall of the annular chamber and the 
outlet passages distributed concentrically. 
According to a particular embodiment, the central tubular mouthpiece is 
screwthreaded externally and the remainder of the first part of the body 
has, at least over part of its height, an external structure which can be 
hexagonal allowing the screwing of said mouthpiece by means of a suitable 
tool. Assembly of the distributor thus becomes very easy. As regards the 
outlet passages, which are distributed concentrically, the latter may be 
made in the form of tapped holes opening into the annular chamber and able 
to receive threaded couplings, to which are connected the beginnings of N 
pipes for the utilization of the fluid receiving equal flows. 
In the particular case where the invention is applied to shuttleless looms 
with pneumatic insertion of the weft, in order to resolve the problem 
described in the introduction, the flow distributor supplies compressed 
air to all the relay nozzles of the same group of N relay nozzles, each 
relay nozzle of this group being connected by a pipe to one of the N 
outlet passages, distributed concentrically, of the distributor. All the 
relay nozzles of the group in question thus receive the same flow of 
compressed air and consequently produce jets with uniform characteristics.

SPECIFIC DESCRIPTION 
FIG. 1 shows very diagrammatically and partially the pneumatic system for 
the insertion of the weft provided on a shuttleless loom, this system 
comprising: an insertion nozzle 1, situated on one side of the loom and 
preceded by a pneumatic weft gripper 2 and numerous relay nozzles 3 
arranged along the insertion axis 4, over the entire width of the loom. 
The relay nozzles 3 are distributed in successive groups 5, for example 
each of seven nozzles. Each group 5 is supplied with compressed air by a 
pneumatic pipe 6, leading to a solenoid valve 7. Immediately downstream of 
the solenoid valve 7, the pneumatic circuit which supplies a group 5 of 
relay nozzles 3 is subdivided into seven branches 8, each of which 
supplies compressed air to one of the nozzles 3 of the group in question. 
The flow distributor which is the object of the invention, designated 
generally by the reference numeral 9, is located downstream of the 
solenoid valve 7 in order to divide the total flow of compressed air, 
travelling through the pipe 6, into seven partial flows which are all 
equal and directed towards the seven relay nozzles 3 by the respective 
circuit branches 8. 
The flow distributor 9, in its particular embodiment illustrated in FIGS. 2 
to 4, is composed of two coaxial parts 10, 11, machined separately then 
joined by fitting one in the other. 
The first part 10 comprises a tubular mouthpiece 12 screwthreaded 
externally, surmounted by a part 13 of larger diameter and having an 
external hexagonal shape. The inner wall of this part 13 is a 
frustoconical surface 14 connected by a rounded transition area 15 to the 
cylindrical inner wall of the mouthpiece 12--see FIG. 4. 
The second part 11, of cylindrical outer shape, has a conical central point 
16 situated opposite the mouthpiece 12 and it is provided on its periphery 
with seven tapped holes 17, distributed concentrically and at regular 
angular intervals all around the axis 18 of the said part 11. Each tapped 
hole 17 receives a screwed coupling 19. 
The two parts 10, 11 also comprise complementary annular parts 20, 21 for 
their assembly by fitting one in the other. When these two parts are 
connected in this way, the frustoconical wall 14 of the first part 10 and 
the conical point 16 of the second part 11 define an annular chamber 22, 
which ensures the continuity of passage between the tubular mouthpiece 12 
and each of the seven tapped holes 17. 
In order to use a flow distributor 9 of this type, the latter is screwed by 
its mouthpiece 12 onto the compressed air supply member and this is by 
means of a spanner adapted to the hexagonal part 13. Each of the seven 
outlet pipes is connected to one of the couplings 19. In view of the 
uniform distribution of the outlet holes 17 all around the axis 18 and of 
the uniform supply of these holes through the annular chamber 22, the 
inlet flow is divided into seven partial flows which are all equal and the 
pressures at the various outlets are also all equal. 
As shown in the drawing, the second part 11 may comprise a central tapped 
blind hole 23, for fitting retaining members of the outlet pipes, 
particularly if the latter are flexible pipes. 
Naturally, the invention is not limited to the single embodiment of this 
flow distributor which was described above, by way of example, in the 
framework of a particular use. On the contrary, it includes all variations 
of construction and application based on the same principle. Thus, in 
particular, it would not be outside the scope of the invention: 
to modify the peripheral parts such as the hexagonal part, which do not 
participate in the flow distribution; 
to resort to solutions other than a screwthreaded mouthpiece, in order to 
form the inlet orifice and to allow the sealed attachment of the flow 
distributor; 
to use other types of fixed or removable couplings, for example with rapid 
assembly, on the outlet passages; 
to modify the number of these outlet passages; 
to use the same distributor for pneumatic circuits in areas having no 
relationship to looms, or even on hydraulic circuits.