COIL OF FLEXIBLE MATERIAL WITH INSERTS IN OUTER WALL

BOBINE EN MATIERE SOUPLE A PAROI EXTERNE DOTEE DE RACCORDS

English Abstract

COIL OF FLEXIBLE MATERIAL WITH
INSERTS IN OUTER WALL
ABSTRACT OF THE DISCLOSURE
In a coil of material wound in a series of figure-8
coils with the cross-overs progressing around the package but
being interrupted at one point to provide a radial opening into
the axial opening of the coil, in order to produce a thick-walled
coil the material is first wound in a normal way with varying
gains in order to produce a set of dense inner layers, while the
outer layers are wound without variation in the gain to produce
a honeycomb structure. The honeycomb section is of greater width
(axially of the package) than the inner layers. A plurality of
pins slidably mounted on a strip are pushed into the outside of the
package through the openings in the honeycomb, whereafter the outer
layers are compressed axially while retaining the pins within the
outer layers. The pins permit payoff of the outer layers without
danger of their collapsing and thereby forming kinks or twists
within the package.

Claims

The embodiments of the invention in which an exclusive property
or privilege is claimed are defined as follows:
1. A method of forming a coil of flexible material
comprising a plurality of figure-8s with the cross-overs of the
figure-8s progressing around the periphery of the coil and having
a radial hole and an axial opening, and with the radial hole
extending from the periphery of the coil to the axial opening of
the coil, which comprises winding a plurality of layers with the
gains varying from layer to layer, thereby producing a relatively
dense central section, and winding an outer section of the coil
with the gains substantially equal from layer to layer, thereby
producing a wider portion having a substantially honeycomb nature,
inserting a plurality of pins through the outside face of the
coil into the outer section thereof, and compressing the outer
section axially to a dimension substantially equal to the dimension
of the inner section.
2. In a method as claimed in claim 1, wherein said
step of inserting a plurality of pins includes the preliminary
step of mounting a plurality of pins on at least one elongated
strip and inserting said mounted pins into the outside of the
coil while held by the strip, said pins being slidable longitud-
inally of said at least one strip during said step of compressing.
3. A coil of flexible material wound in a plurality
of figure-8s having their cross-overs progressing around the
coil in each layer and having a radial opening extending from the
outside into an axial opening of the coil, the coil having a wall
thickness substantially greater than the radius of said axial
opening, and having a plurality of pins spaced from each other
extending from the outer surface of the coil into the outer layers
thereof, said pins being spaced in a direction substantially
parallel to the axis of said axial opening.

4. A coil of flexible material as in claim 3 further
comprising at least one elongated strip including an aperture
for slidably mounting said pins.
5. A coil of flexible material as in claim 4 further
comprising a covering material covering said coil of flexible
material with the end portions of said at least one elongated
strip being folded to engage said covering material.
6. A coil of flexible material as in claim 4 further
comprising a plurality of said elongated strips and groups
of the said plurality of pins are spaced within each respective
elongated strip and said plurality of strips and associated groups
of pins are inserted into said coil at spaced positions around the
periphery thereof.
7. A method as in claim 2 wherein groups of said mounted
pins are associated with a respective elongated strip and further
comprising the step of mounting a plurality of said elongated
strips in spaced relationship about the periphery of said coil.
8. A method as in claim 7 further comprising the step
of enclosing said coil in a covering material and bending the
end portions of said elongated strips to engage said covering
material.
9. A method as in claim 8 wherein said elongated strips
have a length substantially equal to the width of said coil and
the end portions of said strips are extended beyond the side walls
of said coil by said step of compressing.

Description

BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a coil of flexible material
wound in a series of figure-8s with a radial hole into the axial
opening for twistless payout through the hole.
2. The Prior Art
Coils of this sort are known for example from Taylor
. 25 patent No. 2,634,722 and Newman patent No. 3,666,200.
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Such coils are satisfactory where the wall thickness
of the coil is not too great, particularly not greater than the
radius of the mandrel on which the coils are wound. However,
in winding thick-walled coils, particularly when these are
paid out from a position in which the radial opening is arranged
vertically, there is danger that the outer wall layers, when the
inner layers have been withdrawn, will fall off downwardly, and
will thus cause kinks or snarls which will prevent proper payout.
This presents difficulties in producing coils of long length.
SUMMARY OF THE INVENTION
The invention provides a method for producing a coil
having means for preventing falloff of the walls of the outer
layers during payout, and a coil produced by such a method.
According to the invention, the inner layers of the
coil are wound in a normal manner, that is with a different gain
from layer to layer, so that a compact structure is obtained.
Attempts have been made to continue such a wind outwardly to a
considerable wall thickness, and thereafter to insert pins into
the side of the coil from the outside, for purpose of preventing
falloff. It has been found however that such pins, even when made
of a relatively soft plastic material, may penetrate or deform the
material of the coil even a coil formed of wire. It appears that
the forcing of the pins into the side wall therefore damages the
coil and prevents proper payout.

1071~71
According to the present invention, the inner portion
of the coil is wound in a normal manner with a variable gain from
layer to layer, so that the cross-overs do not overlie each other
and a relatively dense section is produced. On the other hand,
after a certain point is reached, the gains are made equal in the
different layers so that the cross-overs substantially overlie each
other from layer to layer. This provides a honeycomb section of low
density, which of course is undesirable.
According to the invention, the pins which are to prevent
fall-off are mounted slidably on a strip of metal and are pushed
into the outer end wall of the coil, the openings in the honeycomb
permitting the pins to enter without breaking or bending the wound
material. Thereafter, the sides of the end portions are compressed
inwardly, that is, parallel to the axis of the axial opening in the
lS coil, and the pins slide inwardly in their carrier. The density of
the end portions is thus substantially increased, and the space
required is thus reduced. At the same time, the pins extend into
the walls of the coil from the outside and prevent the material from
falling off undesirably during the latter part of the withdrawal.
BRIEF DESCRIPTION OF THE DRAWINGS
.
In the drawings:
Fig. 1 shows in cross-section the first step of producing
a coil according to the invention;
- - Fig. 2 shows a pin carrier with the pins carried thereby:
Fig. 3 shows a completed package; and
Fig. 4 shows partly in cross-section a section of the
arrangement of Fig. 2. -
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107117~
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to Fig. 1, the material is wound in the manner
described above, and particularly that described in Newman patent
no. 3, 666,200, on a rotating mandrel 2 having suitable end forms 4.
These end forms are outwardly flared. During the first part of the
wind, that is for example up to the point indicated by the line 6,
the material is wound as described in the above Newman patent, that
is, with varying gains from layer to layer, so that a relatively
dense section is achieved.
The machine is now set to wind with equal angular gains,
and thus forms a honeycomb structure in which the cross-overs in
successive layers lie substantially on top of each other, in the
portion indicated by the area 8, the width of the guide stroke being
sufficient to lay the material across the increasing space between
the end forms.
, Fig. 2 shows a strip of metal 12 with a slot 14 therein.
A plurality of pins 16 having heads 18 are slidably arranged in
the slot, and have flanges 20 engaging the other wall of,the piece
12 opposite ~the heads 18. These flanges may fit closely enough
. . .
to give a frictional grip on the strip 12, so that undesirable
sliding of the pins in the slot is prevented. The pins may be made
of a relatively soft plastic material.
After the winding is completed, several of the pieces 12,
angularly spaced around the periphery, are pushed against the outer
periphery of the winding, and the pins enter into the openings in
the honeycomb formation.
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1~7~17'1
The package is now removed from the mandrel by
taking off the end form and collapsing the mandrel if necessary.
The package is then compressed in a direction parallel to the
axis of the axial opening, as shown for example in Fig. 3. The
pins slide down in the slot 14, and approach each other, and the
layers are collapsed to that a dense outer section 8 is achieved.
The package may then be enclosed in a covering material.
In Figure 3, only end cover 22 are illustrated. The metal strip
12 may then have the ends bent as at 24 around the outside of each
cover 22. This secures the strip in place and ensures holding of
the pins firmly in the package.
During winding, in the manner described above, a radial
opening 26 is formed from the outside of the package into the
axial opening through which the inner end of the material can be
led out.