Hose connecting system and method for providing the hoses with connections

An adhesive hose coupling which comprises an outer connecting element for fixing and enclosing the end of a hose to be coupled having a soul, an inner sleeve having peripheral openings in a smooth outer surface thereof and being attached from an end element, said inner sleeve with end element being adapted to provide connection for the coupling, said inner sleeve being adapted to be expanded against the soul of a hose to be coupled without appreciably restricting the flow of a flowing medium through the hose, and a space filler for disposition in a space formed between said outer connecting element, end element, and a hose to be coupled.

FIELD OF THE INVENTION 
The present invention relates to an adhesive hose coupling filled at least 
partially with space filler and a method for providing hoses with the 
coupling. 
BACKGROUND OF THE INVENTION 
Various fixed couplings are known for high-pressure hoses, particularly for 
connecting hoses reinforced with metal inserts. The most frequently used 
couplings of that are those having pressed, bound and/or screwed 
connections. A common characteristic of such connections is that to 
achieve safe sealing and connection, a higher pressure must prevail in 
course of installation on the surface of element arranged in the inside of 
the hose than the prevailing pressure which may occur in use. 
U.S. Pat. No. 3,347,571 discloses a pressed connecting structure, U.S. Pat. 
No. 1,576,764 discloses a screwed connection, and German Federal Republic 
Pat. No. 1,223,209 relates to a bound connection. 
Couplings fixed by gluing are disclosed for example in Hungarian Pat. No. 
168,837, French Pat. No. 2,214,852 and British Pat. No. 2,088,506 and are 
considered to be the most modern ones in comparison to the aforementioned 
structures. 
However, in the case of glued connections, if one can deal at all with the 
problem of building up the hoses, that it would require a most complicated 
coupling device and installation would require a greater expenditure of 
labor. A further problem is that welding of the special connectors and 
hose couplings having a large diameter cannot be realized in all cases. 
Generally couplings of large diameter highly loadable hoses are assembled 
while the hoses are being built up and if the hoses are based on some 
elastomer then vulcanization is carried out after assembling the hose with 
the coupling. For example, couplings of every marine oil inlet and racking 
hose are made in this manner. With couplings to be installed during the 
building up and when the dimension of the final product are known in 
advance, hoses cannot be produced in greater length for the purpose of 
storage. Row elements below the rigid connecting element are vulcanized 
without applying pressure or at medium pressures and, therefore, bubbles 
and delamination of layers can often take place. 
DESCRIPTION OF THE INVENTION 
The aim of the invention is to develop a hose coupling without the 
drawbacks of known couplings and to provide a method for the assembly of 
the couplings on the finished hoses. 
The invention is based on the recognition that couplngs faultlessly 
functioning under all prevailing circumstances can be obtained by the 
simultaneous application of an inner supporting element and a space filler 
which enables that coupling can be improved between the reinforcing layer 
and the coupling by the internal pressure. 
The coupling of the invention, i.e. the elements thereof can be easily and 
quickly installed separately from the actual production of the hoses. 
Thus, safety of the coupling can be improved and optional elements 
interconnecting the ends can be welded to the connections. 
The essential characteristic of the coupling according to the invention is 
in that inner sleeve of the outer connecting element serving for fixation 
and encasing, and the element for sealing and coupling are interconnected, 
while the inner sleeve is expanded and suitably has a smooth surface and 
is provided with one or more openings to allow the introduction of the 
inner pressure and/or it is connected to the element for sealing and local 
connection so as to enable penetration of the inner pressure between the 
two elements. The space filler is arranged in the space confined by the 
hose reinforcement, the sealing and coupling end element, the outer 
connecting element and the hose cover. 
The inner part of the hoses formed with an annular cross-section and made 
of rubber, is referred to in this field as the "soul" of a hose. In the 
coupling according to the invention the glued, vulcanized and/or pressed 
"soul" is located between the sealing and coupling end element and the 
inner sleeve. 
In a preferred embodiment of the invention the outer connecting element is 
connected by one single thread to the sealing and coupling end element and 
the hose cover. Expansion of the surface needed for connection is also 
achieved with one single screwed connection. 
According to a further preferred embodiment of the invention the diameter 
of the inner sleeve is enlarged by pressing. 
The outer connecting element and the cover are interconnected with a 
conical end thread, to prevent penetration of some external medium. The 
connecting means is provided by a separately applied flexible sleeve 
assuring gradual external transition between the parts of the coupling. 
There is a electrically conducting connection between the inner sleeve and 
the sealing and coupling end element.

DESCRIPTION OF THE DRAWING 
The invention is described in detail by means of a preferred embodiment 
with the aid of the accompanying sole figure of the drawing, which is a 
partial cross section showing a hose coupling, according to the invention. 
DESCRIPTION OF PREFERRED EMBODIMENT 
A sealing and coupling end element 2 (hereinafter referred to as 
"end-element") and an outer connecting element 1 are screwed together. 
This end-element 2 can be welded at 14 to an inner sleeve 3. Welding can 
be carried out prior to installing the connection. Expediently the outer 
connecting element 1 is formed with an identical thread-profile throughout 
its full length. Connection of a main reinforcing layer 5, fixation of the 
element 2 with a screw-thread and connection of the cover 9 of the hose 10 
are achieved with the same thread. Connection of the soul 4 of the hose 
sealing are achieved by gluing, vulcanizing and/or pressing the soul 
between the end-element 2 and the inner sleeve 3. The soul 4 of the hose 
is bent back over the carcass 8 or on the end of the carcass 8 there is a 
layer formed which is impermeable to liquid and gas. The space between the 
main reinforcing layer 5, the outer connecting element 1, the end-element 
2 and the cover 9 is filled at least partially with a space-filler 6 which 
is separate from the material of the hose. 
The sleeve is expanded after having inserted the inner sleeve 3 into the 
inside of the hose 10. It does not narrow the inner diameter of the hose, 
and if yes, then only to a negligible extent. The pressure formed as a 
result of the expansion promotes sealing of the soul and fixation of the 
reinforcing layer 5. The surface of the inner sleeve 3 is provided with 
one or more openings 12 and during expansion its diameter is enlarged to 
such an extent that with rising pressure introduced within the inner 
sleeve 3 presses the reinforcing layer 5 toward the outer connecting 
element 1. The surface of inner sleeve 3 is smooth and it does not contain 
any element that could prevent penetration of the internal pressure above 
a certain pressure level. 
The unexpected consequence of this formation is that fixation of the main 
reinforcing layer 5 is guaranteed by the connection due to the frictional 
shearing forces arising on a the threaded surfaces even if no adhesive was 
applied to the contacting surfaces. Strength of the coupling is increased 
by introducing a space filler 6 which establishes an adhesive joint 
between surfaces. Considering that adhesion and frictional shearing force 
resulting from internal pressure can carry the load in itself then safety 
of the bond can be considerably increased by their combined application. 
The inner sleeve 3 is suited for assuring axial loadability of the hose 
even when if there is no internal pressure in the hose. The inner sleeve 3 
prevents detachment of the reinforcing layer 5 from the coupling under 
tensile loading. 
Impermeability to liquids is achieved partly by a subsequently applied 
outer flexible sleeve 7 and the threaded connection between the outer 
connecting element 1 and the cover 9 comprising a conical threaded 
portion. 
In applying the coupling according to the invention bubbles that result 
from the lack of pressure and appearing under the connections during its 
production can be eliminated. A further advantage is in that sealing 
between the connections can be formed in a fully closed space with the 
highest safety. 
The method for producing the coupling according to the invention is also a 
part of the invention. The end of the finished hose is formed with 
stagger, on the end of the textile inserts a layer is formed that is 
impermeable to liquid and gas. A sealing tongue is thus obtained. The 
connecting elements are applied, thereafter the inner sleeve is expanded 
under the sealing tongue; the outer shell is arranged and the space-filler 
delivering the internal pressure is introduced between the reinforcing 
inserts and the connection in the already installed connection, thereafter 
the inner sleeve is also expanded below the reinforcing inserts. 
Accordingly, in course of the process according to the invention the end of 
the hose is staggered by using a scraper which is turned around the axis 
of the hose. Thereafter the end of the soul 4 is bent back to the end of 
the carcass 8 or a separate layer formed that is impermeable to liquid and 
gas, thus obtaining the sealing tongue. The end-element 2 and the inner 
sleeve 3 are arranged. Thereafter the inner sleeve 3 is expanded 
expediently below the sealing tongue. Next the outer connecting element is 
screwed onto the end-element 2 and the cover 9. When it is desired, the 
end of the soul 4 and the surface of the end-element 2 contacting the 
sealing tongue are primed for gluing of for the bonding of metal to 
rubber. 
In the next phase of the process the space between the main reinforcing 
layer 5 and the outer connecting element 1 or at least the space in the 
vicinity of the ends of the reinforcing layer 5 is filled with the 
space-filler. The purpose of this operation is to prevent rupture of the 
infrastructure at the ends of the reinforcing layer. Space-filling can be 
expediently achieved in additional areas by extending the space-filling 
under the cover 9, the outer connecting element 1 or by reducing the inner 
diameter of the outer connecting element 1, eventually by combination 
thereof. Suitably a binding-gluing material can be used as the specefiller 
6 and that manner safety of bond can be increased. 
Thereafter a tool exerting internal pressure is used to expand the part of 
the inner sleeve 3 under the reinforcing layer 5. By the expansion it can 
be achieved that the inernal sleeve should not reduce the flow 
cross-section at all, and if yes, then only to a negligible extent. The 
pressure of the medium delivered in the hose also presses the reinforcing 
layer 5 through the hose structure against the inner surface of the outer 
connecting element 1. This effected increasing the inner pressure 
increases the forces within the coupling and the reinforcing layer 5. The 
ability to introduce pressure, passage of transport medium through the 
coupling will be improved by the fact that the outer surface of the sleeve 
3 below the soul 4 is smooth and it is provided with the proper openings 
12. 
The outer flexible shell 7 prevents penetration of moisture and it provides 
a gradual modules transition, the inner surface of which is expediently 
glued or otherwise bound to the structural elements below it with a rubber 
to metal or rubber to elastomer bond. 
Optionally, as a finishing step of operation, the coupling also can be 
subjected to heat treatment. 
The coupling according to the invention can be successfully employed also 
with synthetic hoses.