Apparatus for producing reinforced hose

A reinforced hose is disclosed having an overlapping spiral tube of reinforcing fabric embedded between inner and outer layers of extruded material in which the fabric is fully extended and tensioned during the manufacturing process and a good bond is obtained between the layers through the openings in the fabric. Also disclosed is a dual feed extrusion head for manufacturing such hose in which an outer nozzle assembly includes two annular plates bolted together and separable for easy cleaning. Such outer nozzle assembly is adjustably mounted on the forward end of the extruder head frame. A tubular inner nozzle assembly is provided with a nozzle at the exit end thereof located within the outer nozzle assembly and spaced therefrom. A fabric guide is positioned around the inner nozzle assembly and establishes the spiral configuration of the reinforcing fabric which in turn feeds in between the inner and outer nozzles. The inner nozzle is axially adjustable with respect to the outer nozzle. The extrusion head is constructed so that substantial access in clearance is provided around the inner nozzle assembly to provide an open feed path for the fabric as it approaches the fabric guide. A central pin which is axially adjustable within the inner nozzle assembly constitutes part of the nozzle and also provides means to expand the inner layer to extend the fabric and insure good bonding contact between the two layers of the hose.

BACKGROUND OF THE INVENTION 
This invention relates generally to reinforced hose and more particularly 
to a novel and improved reinforced hose, to a novel and improved method 
for manufacturing such hose, and to a novel and improved extrusion head 
for producing such hose. 
PRIOR ART 
Generally in the past reinforced hose such as reinforced rubber hose has 
been formed by a three step process in which an inner cylindrical tube 
portion is extruded, a reinforcing layer is applied to the inner tube 
portion by braiding machines, and subsequently, an outer tube is extruded 
over the braid. Such procedure requires large capital investment in 
manufacturing equipment, provides a production rate which is limited by 
the rate at which the braid can be produced, and often results in the hose 
having a poor bond between the two layers of hose material. 
More recently, a system has been developed in which a strip or strips of 
reinforcing fabric is fed into a dual extrusion head which functions to 
sequentially or simultaneously extrude the two tubular layers with the 
reinforcing material positioned at the interface therebetween. Such 
devices are described in the U.S. Pat. to Schiesser Nos. 3,697,209 and 
3,856,447. 
SUMMARY OF THE INVENTION 
The present invention provides a novel and improved dual feed extrusion 
head operable to produce an improved reinforced hose. In such head a strip 
of fabric is fed as a spiral tube into a zone around the inner extrusion 
nozzle which produces the inner tube portion and within the outer 
extrusion nozzle which produces the outer tube portion. The preferred head 
is constructed so that at least a substantial portion of the fabric path 
is visible and accessible. 
The nozzle is constructed for full adjustment with most of the adjustments 
being operable even while the head is in use. The structure is also 
arranged for easy assembly and disassembly permitting easy cleaning of the 
head after its use. Further, the structure is relatively simple to produce 
at relatively low cost. 
The head is provided with a central pin with an enlarged portion which 
expands the inner layer of hose material flowing from the inner orifice as 
it progresses along the head. This causes the inner tube portion to expand 
against the reinforcing material and insures that the strands of the 
fabric are fully extended. Further, it insures that the hose material 
flows through the fabric and establishes a superior bond between the two 
layers of material without the use of adhesives. Since the hose produced 
by the head includes an improved bond between the two layers of material 
and incorporates fully extended and tensioned fabric an improved hose 
product is provided.

DETAILED DESCRIPTION OF THE DRAWING 
FIG. 1 illustrates a short piece of reinforced hose 10 in accordance with 
the present invention. Such hose may be formed of extrudable plastic, 
rubber or other elastomeric materials and includes an inner tube portion 
11 and an outer tube portion 12 with a fabric reinforcement material 13 
along the interface between the two tube portions 11 and 12. Such fabric 
material may be of any suitable knitted or woven type which can be 
manufactured in a long strip with a substantially open weave to allow the 
material forming the inner and outer tubes to bond through the openings in 
the fabric. In FIG. 1 the thickness of the fabric is exaggerated for 
purposes of illustration. 
The strip of fabric 13 is formed in a spiral overlapping tube or cylinder 
in a manner described in more detail below and it is provided with an 
overlapping section extending from 14 to 16. As mentioned previously the 
fabric should have an open weave so that the material forming the two 
portions 11 and 12 can flow through the openings in the fabric to form a 
bond. Preferably the fabric is sufficiently open so that the material 
flows through and bonds even in the overlapping zone between 14 and 16. 
In accordance with the present invention the material forming inner tube 
portion 11 is extruded through an inner annular nozzle with an inside 
diameter significantly smaller than the final diameter produced in the 
finished hose. Such material is expanded during the manufacture to cause 
the fabric to be extended fully and to insure that the material forming 
the inner tube portion 11 flows into the openings in the fabric into tight 
bonding engagement with a material forming the outer tube portion 12. 
Because the fabric is fully extended during the manufacture of the hose, 
the finished hose contains a fabric which is tensioned and is free of 
wrinkles or the like which could otherwise allow expansion of the hose 
when pressurized before the fabric reinforcing material is tensioned to 
resist further expansion. 
The hose of FIG. 1 is preferably formed by an extrusion head of the types 
illustrated in the remainder of the drawings. Referring to FIGS. 2 through 
4 such extrusion head is provided with a body or frame assembly 17 
consisting of two body members 18 and 19 which abut along an interface 21 
and are bolted together by bolt fasteners 22. In use the two body members 
are maintained in the assembled position illustrated and are formed into 
separable parts primarily to allow easy disassembly of the unit for 
cleaning or the like and for ease of manufacture. The body assembly 17 
includes a forward cylindrical portion 23 which is externally threaded at 
24 to receive a face ring 26 which is threaded onto the cylindrical 
portion 23 for mounting an outer nozzle assembly 27 and is removable to 
allow removal of such assembly. Wrenching openings 28 are formed in the 
ring 26 to facilitate its installation and removal. 
Extending back from the forward end of the body assembly 17 is a 
cylindrical opening 29 which is co-axial with the center axis 31 of the 
extrusion head and extends to a radial wall 32. Such cylindrical opening 
29 is sized to receive the outer nozzle assembly 27 with substantial 
clearance when such nozzle assembly is installed (as best illustrated in 
FIG. 3) against the radial face 32. The face ring is provided with a 
radial face 33 which engages the forward face of the outer nozzle assembly 
to clamp it against the radial face 32 of the body assembly when the 
nozzle is installed. The nozzle assembly, however, can be removed by 
merely removing the face ring 26 for ease of cleaning and disassembly. 
The nozzle assembly 27 is radially adjusted within the openings 29 by four 
peripherally spaced adjustment screw members 34 which are threaded through 
the cylindrical portion 23 and engage the outer surface of the outer 
nozzle 27 to radially position the nozzle within the cylindrical opening 
29. Preferably each of the adjusting screws 34 is provided with a handle 
portion 36 for ease of adjustment. The adjustment screws are located at 
90.degree. spacing around the axis 31 and are positioned along opposite 
diagonals. In FIG. 3, two of the screws are shown as displaced to the 
vertical plane of the extrusion head for purposes of illustration but it 
should be understood that the adjustment screws are preferably located 
along the diagonals as illustrated in the remainder of the drawings. 
Extending back from the radial face 32 within the body assembly is a 
central bore 37 proportioned to receive a fabric guide 38 with a close 
fit. The housing member 18 is formed with a vertically extending cut-out 
or recess 39 which extends to a step section at 41 (as best illustrated in 
FIG. 5) which in turn is open to the central bore 37 so that the position 
of the fabric guide 38 along the bore 37 can be visually determined at any 
time. 
The fabric guide 38 is formed with a threaded central passage 42 through 
which an inner tube 43 is threaded as best illustrated in FIG. 3. A spiral 
shaped groove 44 is cut through the fabric guide as best illustrated in 
FIG. 7 and provides a first end 46 substantially adjacent to the bore 42 
and an opposite end at 47 which is radially spaced outwardly from the 
adjacent portion of the groove extending from the end 46. The two ends of 
the groove overlap so that when a strip of fabric reinforcing material 
passes through the groove 44 it assumes a spiral overlapping tube shape. 
When desired a sheet metal generally conical guide 40 is mounted on the 
entrance end of the guide 38 to assist the forming and feeding of the 
fabric into the groove 44. 
The body assembly is provided with a pair of axially extending spaced and 
parallel support projections 51 and 52 which extend along opposite sides 
of the central axis 31 as best illustrated in FIGS. 2 and 4 to receive and 
support a U-shaped weldment 53 consisting of a cross plate 54 and parallel 
legs 56 and 57 which extend along opposite sides of the mounting 
projections 51 and 52 respectively and constitute the frame extension. 
Each of the legs 56 and 57 are provided with axially extending slots 58 to 
receive a pair of clamping screws 59 to lock the weldment 53 in its 
adjusted position with respect to the body assembly 17. A pair of jack 
screws 61 are threaded through the cross plate 54 and bear at their ends 
against the ends of the supports 51 and 52. Axial adjustment of the 
weldment can therefore be accomplished by loosening the screws 59 and 
adjusting the jack screw 61. After adjustment the screws 59 are again 
tightened to maintain the weldment in its adjusted position. 
Secured to the cross plate 54 is an entrance fitting 62 which is externally 
threaded at 63 so that it can be connected to a tuber which pressurizes 
and supplies the material for forming the inner tube portion 11 of the 
finished tube. Preferably the entrance portion 64 of the fitting 62 is 
shaped (as best illustrated in FIG. 3) substantially as an offset cone to 
channel the material flowing through the fitting in an offset manner to a 
cylindrical exit passage 66. Such offset shape laterally displaces the 
entrance end of the conduit which is connected to the tuber and provides a 
relatively straight path along which the reinforcing fabric 13 feeds into 
the nozzle as illustrated in the dotted line. The rearward end of the 
central tube 43 is welded or otherwise suitably connected at 67 to the 
entrance fitting 62 in alignment with the exit passage 66 so that material 
supplied from the tuber connected to the fitting 62 is channeled for flow 
in along the interior of the tube 43. 
The forward end of the tube 43 is internally threaded at 68 to receive a 
central pin 69. The rearward end of the pin is provided with a plurality 
of radially extending fin like projections 71 which are peripherally 
threaded so that the pin can be threaded into the tube and its position 
along the length of the tube can be adjusted by appropriate rotation to 
thread the pin either in or out as desired. Material flowing in along the 
passage 73 within the tube 43 passes between the fins 71 and continues to 
flow over the central pin 69 to an inner annular orifice or nozzle 74 
provided by the central pin 69 and the exit end of the tube 43. Preferably 
the pin 69 is formed with a tapered portion 76 of gradually increasing 
diameter which cooperates with the passage 73 to restrict the flow of 
material along the passage as it approaches the nozzle 74 so that the 
material flowing past the fins reforms as a homogeneous annular column 
before reaching the nozzle 74. 
The outer nozzle assembly 27 is formed of two nozzle plates 81 and 82 each 
of which are provided with conical wall portions 83 and 84 respectively 
which are spaced from each other when the two nozzle parts are bolted 
together by fasteners 86 to provide a conical flow path 88 terminating at 
an outer orifice or nozzle at 87. Extending along the outer periphery of 
the conical flow passage 88 is an arcurate supply passage 89 open to an 
inlet pipe 91 connected to a tuber which supplies the material forming the 
outer tubular portion 12 of the hose. 
Generally, two tubers are utilized to supply the extrusion head, however in 
some instances it may be desired to supply the material for both the inner 
and outer tube portions from a single tuber of suitable capacity and 
provided with flow control means for balancing the flow between the two 
nozzles. The use of two tubers, however, provides good flow control 
adjustment to properly balance the flows through the two nozzles. 
The inlet pipe or tube 91 fits through a clearance opening 92 in the 
cylindrical portion 23 so that it does not restrict the adjustment 
movement of the outer nozzle assembly 27. The arcuate flow passage 89 
extends along the interface between the two nozzle parts 81 and 82 to 
oppositely dispose to gates 93 and 94 so that material is supplied to the 
conical passage 88 at peripherally spaced locations. The gates are 
positioned and sized so that a material enters the conical passage 88 and 
is directed in a uniform manner to the outer nozzle 87 as a homogeneous 
annular mass. 
The guides 40 and 38 establish the spiral configuration of the fabric strip 
13 which passes through the guide and along an annular passage 96 around 
the tube 43 and around the inner nozzle 74 so that as material is extruded 
through the inner nozzle 74, it is located within the spiral overlapping 
tubular fabric strip which is moving along the annular passage 96 within a 
bore 97. The amount of overlap is selected to provide sufficient bonding 
of the overlapped fabric to resist the pressures expected to be 
encountered. Usually an overlap of at least one quarter of an inch is used 
in a one inch outside diameter hose. 
The central pin 69 is preferably formed with a relatively large knob 
portion 98 positioned downstream from the inner orifice 74 which engages 
the inner surface of the annular column of material extruding out through 
the inner nozzle 74 and causes such material to be radially expanded into 
intimate contact with the inner wall of the tube of the fabric. Such 
inclined surface 99 also may be positioned as illustrated beyond the outer 
nozzle 87 so that it presses the inner tubular portion or layer of 
extruded material outwardly toward the outer layer extruding through the 
outer nozzle 87 to insure that sufficient pressure is developed to cause 
the material from the two layers to be bonded together through the 
openings in the fabric. Preferably, the pin is formed with a cylindrical 
land or wall 101 which is located radially within a cylindrical wall 102 
which cooperate to constitute a third nozzle like structure through which 
the two layers must pass. Such annular passage between the two walls 101 
and 102 is preferably sized so that it has a cross sectional area which is 
no greater than the total cross sectional area of the inner and outer 
tubular portions extruding through the inner and outer nozzles 74 and 87 
respectively. This relationship insures that the two layers are pressed 
tightly together so that a permanent and superior bond is established 
between the two layers through the fabric. 
Of course the flow of the extruding material out along the nozzle carries 
the fabric into the nozzle zone and the process is essentially continuous. 
In fact, if desired, lengths of fabric can be joined by stitching them 
together or heat welding the fabric if the fabric is formed of a material 
which can be heat welded so that the process can be carried out 
substantially continuously. When the hose material is rubber or curable 
material the extruded hose is subsequently cured. The structure of the 
nozzle is arranged so that it can easily be disassembled after operation 
to completely clean all of the parts. Removal of the face ring 26 and the 
supply tube 91 allows removal and disassembly of the outer extrusion 
nozzle assembly 27. Similarly, the central pin 69 can be threaded out of 
the end of the tube 43 and the tube 43 can be removed by merely removing 
the bolt fasteners 59. 
Further, the structure is arranged to provide adjustment of substantially 
all of the parts. The fabric guide 38 can be threaded forward or 
rearwardly along the tube 43. The center pin can be threaded in or out of 
the tube for adjustment purposes. The inner nozzle system consisting of 
the tube 43 and pin can be adjusted axially with respect to the outer 
nozzle assembly and is radially located by the fabric guide. Since the 
outer nozzle assembly 27 can be radially adjusted, complete adjustment of 
the relative positions of the two nozzles is provided. 
Still further, the fabric approaching the nozzle is substantially 
accessible. In the illustrated embodiment of FIGS. 1 through 7 a sheet 
metal guide 40 is illustrated which is formed as a spiral cone like shape 
and is supported on the fabric guide immediately adjacent to the grooves 
44 as best illustrated in FIG. 5. Such guide 40 assists in forming the 
spiral of the fabric which enters the unit substantially in a flat 
condition from the right side as viewed in FIG. 3. 
It should be pointed out that in some instances it may be desired to feed 
the fabric in from below the fitting rather than above the fitting as 
illustrated in FIG. 3. In such instance it is merely necessary to remount 
the U-shaped weldment in the opposite orientation and to insure that the 
overlapping section of the fabric guide 38 is again in alignment with the 
laterally projecting portion of the entrance fitting 62. Further, with 
this invention means can be provided between the fabric guide 38 and the 
inner nozzle to bond, heat weld or otherwise connect the overlapping 
layers of the fabric so that the fabric is a true tube before the inner 
and outer layers are provided. In most cases, however, sufficient bonding 
of the overlapping portions of the fabric is provided by the material of 
the inner and outer layers. 
With the method in accordance with the present invention the fabric strip 
is fed around an inner nozzle which produces a tubular column of extruding 
material having an inside diameter substantially less than the final 
inside diameter of the hose. Similarly, an outer tubular layer is extruded 
in around the outside of the fabric and the inner layer is increased in 
diameter to insure that the fabric is extended and tensioned, and to 
create sufficient pressure between the two layers to cause them to bond 
through the openings in the fabric. In the illustrated preferred 
embodiment the inner nozzle is located ahead of the outer nozzle so that 
the inner tubular layer is formed within the fabric before the outer 
tubular layer is applied to the outside of the fabric and subsequently 
both layers are caused to pass through a restricted orifice like structure 
which insures proper sizing of the tube and intimate bonding contact 
between the two layers. 
FIGS. 8 and 9 illustrate a second embodiment of this invention. In this 
embodiment similar reference numerals are used to designate similar parts 
with a prime added to indicate that reference is being made to the second 
embodiment. 
Insofar as the extruding function is concerned the embodiment of FIGS. 8 
and 9 is essentially identical to the embodiment of FIGS. 2 through 7. In 
this instance however, the supply tube 43' through which the material 
forming the inner layer flows is threaded at its outer end at 45' to 
receive a curved entrance tube 50'. With this structure the entire 
entrance fitting 62' is laterally displaced from the central axis 31' so 
that the strip of fabric can commence to wrap around to its spiral shape 
before reaching the head itself. In fact, the feed of the fabric 13' can 
be in substantial alignment with one side of the groove 44' so that the 
spiral form of the fabric can be established easily by the time the fabric 
reaches the guide 38'. In this structure the U-shaped weldment 53' is also 
formed with an offset section 55' but is adjustable along the central axis 
31 in the same manner as in the prior embodiment. 
If it is necessary to provide a stiffening of the curved section 50' fillet 
plates 60' can be welded or otherwise suitably connected to the curved 
section of the tubing. With this embodiment, where full access to the 
fabric is provided until it reaches the fabric guide, the movement of the 
fabric can be easily monitored to insure proper operation. 
In this second embodiment the remaining portions of the extruding head are 
essentially identical to the corresponding parts of the first embodiment 
both as to shape and function. Therefore, the detailed description of the 
first embodiment can be referred to in connection with the second 
embodiment excepting as noted above. 
Although preferred embodiments of this invention are illustrated it is to 
be understood that various modifications and rearrangements may be 
resorted to without departing from the scope of the invention disclosed 
and claimed.