U.S. patent number 3,684,284 [Application Number 05/073,330] was granted by the patent office on 1972-08-15 for pile fabric method and product.
This patent grant is currently assigned to Chas. W. House & Sons Incorporated. Invention is credited to George Tranfield.
United States Patent |
3,684,284 |
Tranfield |
August 15, 1972 |
PILE FABRIC METHOD AND PRODUCT
Abstract
A pile fabric designed particularly for use as a cover of a
tennis ball. The fabric has a base structure comprising knitted
cotton yarns, preferably in two layers laid back-to-back. A pile
surface is provided on one side of the base structure by a fleece
preferably composed of a plurality of carded webs having synthetic
components including polyester, acrylic, polypropylene fibers. The
webs are integrated with one another and with the base structure by
the fibrous components of the webs passing substantially
perpendicular to the plane of the webs through the adjoining webs
and the base structure. When the disclosed fabric is used as a
tennis ball cover, it is cut into blanks of conventional
configuration and applied to the core structure of the tennis ball
by suitable adhesives. The integration of the webs and base
structure into a unitary fabric is effected by a series of needling
operations, selected ones of which provide full penetration of the
assembled layers with fine needles, and others of which provide
only partial penetration of the assembled layers by course
needles.
Inventors: |
Tranfield; George (Hatfield,
PA) |
Assignee: |
Chas. W. House & Sons
Incorporated (Unionville, CT)
|
Family
ID: |
22113094 |
Appl.
No.: |
05/073,330 |
Filed: |
September 18, 1970 |
Current U.S.
Class: |
473/607; 28/109;
28/155; 28/162; 156/148; 428/91 |
Current CPC
Class: |
A63B
39/08 (20130101); Y10T 428/2395 (20150401) |
Current International
Class: |
A63B
39/08 (20060101); A63B 39/00 (20060101); A63b
039/06 (); D03d 027/00 (); D04h 011/00 () |
Field of
Search: |
;161/62,67,80,81,154-156,167 ;28/72P,72.2R ;66/202 ;156/148
;273/61R,61B |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
279,254 |
|
Sep 1964 |
|
AU |
|
1,152,240 |
|
May 1969 |
|
GB |
|
Primary Examiner: Van Balen; William J.
Claims
I claim
1. A blank for covering a tennis ball comprising a segment of a
composite felted fabric structure having a felted pile surface on
one side and a smooth surface on the other side, and a coating of
adhesive material applied to the smooth surface of the blank for
adhesively attaching said blank to the core of a tennis ball, said
fabric comprising a layer of fibrous material in the form of
discrete fibers of determinate length, said fibrous layer being
densely consolidated through entanglement of the individual fibers
of the character produced by needling operations, and a base
structure comprising two layers of a fabric knitted with coherent
yarns, the fibrous layer and the base structure being thoroughly
integrated throughout by at least a major proportion of fibers
penetrating through all of said layers and being looped around the
yarns in the knitted structure of the layer on the smooth side of
the composite fabric.
2. A product according to claim 1 wherein said two layers knitted
base fabric comprise flat knits in which all of the needle loops
are positioned on one face of the fabric, the back face being
relatively smooth, said two layers oriented with the smooth back
faces confronting one another in face-to-face engagement.
3. A product according to claim 2 wherein said layers are integral
parts of a knitted tubular structure which is flattened with the
smooth face of the knitted structure on the interior of the
tube.
4. A product according to claim 2 wherein each knitted layer
comprises two yarn systems which knit and tuck alternately and in
alternate wales so that the yarns of one system tuck when the yarns
of the other system knit.
5. A tennis ball comprising a resilient core of elastomeric
material and a covering comprised of two blanks made in accordance
with claim 1 and securely bonded to said core by said adhesive
coating.
6. A method of producing a pile fabric having a pile on one surface
and being smooth on the opposite surface comprising the steps of
supplying a web of fibrous material having staple lengths in the
range of at least 1 1/2 inches supplying a base structure of
knitted fabric from yarns of a predetermined size in a given
knitted construction, needling said web through said base structure
by penetrating felting needles downwardly through said web and then
through said base structure, thereafter needling said composite
structure from the opposite surface to project the felting needles
through said base structure and thereafter through said fibrous
layer to remove the major portion of loose fiber ends from the
undersurface of said composite structure, selecting felting needles
in the aforesaid needling operations having a fine thickness
relative to the knit construction of said base structure so that
said felting needles may penetrate through said base structure
without rupturing the yarns of said knitted structure, thereafter
needling said composite structure from the fibrous face thereof to
consolidate the web of fibrous structure in the composite fabric
structure, selecting coarser felting needles for said consolidating
needling operation, and controlling the penetration of said coarser
felting needles so as to avoid engagement of the barbs of said
coarser needles with the knitted yarns of the knitted base
structures, thereby avoiding rupture of the yarns by said
consolidating needling operation.
7. A method according to claim 6 including an additional step of
needling said consolidated web with fine felting needles which
penetrate through the entire consolidated structure, the fineness
of the needles being selected to avoid rupture of the yarns of the
knitted structure by the barbs of said fine needles.
Description
The present invention relates to a novel pile fabric and a method
of making the same, and has particular application to a fabric for
use as the outer covering of a tennis ball.
Prior to the present invention the major manufacturers of tennis
balls employed a woven fabric having a pile formed thereon by a
napping operation. The fabric is normally supplied in continuous
lengths and the typical blanks which are applied to the spherical
core of the ball are cut from the continuous lengths of woven
material on the bias so that the stretch and conformability of the
blanks along the longitudinal and transverse axes of the blank are
affected substantially equally by the characteristics of the warp
and the weft of the woven structure.
The production of tennis balls using such fabrics has required the
use of skilled hand workers for applying the blanks to the core
without having wrinkles or other defects present in the finished
ball, and considerable waste has been tolerated because of fraying
along the edges of the blanks and by the wastage in the cutting
operations due to the need for orienting the blanks on the
bias.
Previous attempts to improve the tennis ball cover material have
not proved commercially acceptable for one reason or another. The
cost of the cover material cannot be substantially higher than the
cost of the previously-used material. The durability of the
material cannot be reduced, and the material must be possessed of
good aesthetic properties.
With the foregoing in mind, the present invention provides an
improved fabric which has particular application for covering
tennis balls which has properties substantially improved over the
properties of the conventional cover material.
More particularly the present invention provides a fabric structure
which has improved formability when compared with a conventional
woven structure, and is produced on apparatus which is more
economical to own and operate than the equipment used for the
manufacture of conventional tennis ball cover material.
More particularly the present invention contemplates a fabric
composed of a double layer of knitted yarns having on one side of
the double layer a pile surface composed of fibrous webs needled
into an integrated fabric having a pile on one surface and being
substantially smooth on the other surface.
The present invention also contemplates a novel method of forming
such a structure wherein the needling operations are controlled to
correlate the penetration of the needles with the gage of the
needles and the construction of the knitted layers so as to avoid
rupture of the yarn components of the knitted layers during the
needling operation.
All the objects of the invention are more fully set forth
hereinafter with reference to the accompanying drawing wherein:
FIG. 1 illustrates a tennis ball with a portion broken away to
illustrate the construction embodying the fabric of the present
invention. FIG. 2 is a plan view of a blank of the form used in
covering a tennis ball with fabric of the present invention.
FIG. 3 is a side elevation of the blank shown in FIG. 2.
FIG. 4 is an enlarged fragmentary transverse sectional view showing
the components of the fabric used in the blank of FIG. 3 separated
from one another.
FIG. 5 is a greatly enlarged sectional view taken on the line 5--5
of FIG. 4 illustrating the orientation and arrangement of the two
knitted layers in the base structure of the fabric.
FIG. 6 is a diagrammatic illustration of a needling operation
illustrating the components of the fabric in position between the
needles and the base plate of a needling machine; and
FIG. 7 to 10 inclusive illustrate the needling action which occurs
in sequential steps during the integration of the webs and the
knitted base structure in the fabric.
Referring now to the drawing, FIG. 1 illustrates a tennis ball
embodying a fabric made in accordance with the present invention.
Apart from the novel fabric, the tennis ball is of conventional
construction. As shown in FIG. 1, the ball comprises a resilient
spherical core 14 of elastomeric material. In the present instance
the core 14 comprises a hollow sphere of rubber or the like which
is pressurized to provide the desired degree of resiliency in the
finished product. The spherical core 14 is covered with a pair of
blanks 15,15 identical in outline, as shown in FIG. 2 so as to
completely enclose the spherical core 14 when abutted along their
margins to form a seam as shown at 17 in FIG. 1. The blanks 15 are
cemented to the core 14 as diagrammatically illustrated at 16 in
FIG. 1 by a suitable adhesive compound, which is coated on the
undersurface of the blanks to form an intimate surface-to-surface
bond firmly anchoring the blanks 15 when they are applied to the
core 14. The adhesive material, or another adhesive compound, is
applied along the peripheral margins of the blanks to assist in
preventing raveling of the material of the blank and to insure
against separation of the two blanks along the seam line 17 after
the blanks are applied to the core. The line of adhesive material
17 also may be pigmented to serve as decorative ornamentation, as
for example when it is of a color contrasting with the color of the
exposed surfaces of the blanks 15. As indicated in FIG. 3, the
blanks 15 comprise a fibrous outer pile surface 18 constituting the
pile of the fabric and a smooth undersurface 19 on which the
adhesive coating 16 is applied prior to application of the blanks
to the core 14.
As illustrated diagrammatically in FIG. 4, the fabric from which
the blank 15 is made includes a layer of substantially untwisted
fibers of textile material which forms the pile surface 18 and a
base structure 22 of fabric formed from yarns or filaments which
comprises the major element of the undersurface 19.
In accordance with one feature of the present invention, the base
structure 22 comprises a double layer of knitted fabric. As shown
in FIG. 5, the knitted structure is a flat knit in each layer
wherein all of the needles loops project from the same side of the
fabric. As shown, the lower layer 23 of the structure is reversed
relative to the upper layer 24 so that the needle-loop surfaces of
the two fabrics are remote from one another leaving the smooth back
surfaces disposed face-to-face. In the present instance, the stitch
construction embodies two yarn systems which knit and tuck
alternately and in alternation on the needles of a weft knitting
machine. By this arrangement, a dense base structure is obtained by
the imtimate contact between the confronting backs of the two
fabrics.
In the illustrated embodiment of the invention, the layers 23 and
24 comprise integral parts of a single fabric knitted as a tube on
a circular knitting machine and thereafter folded flat with the
smooth surface of the knitted fabric on the interior of the tube.
It is understood that other knitting operations will produce
comparable results wherein by reason of the knitted construction of
the fabric, the inherent stretch and recovery in substantially all
directions provides a balanced knit structure which is highly
conformable to curved surfaces such as the spherical surface of the
core 14. In the present instance the knitted fabric embodies 18/1
carded cotton yarn knitted with a density of approximately 16 wales
per inch and 30 courses per inch. The use of cotton in the base
structure provides good compatibility with the adhesive coating 16
and the adhesive along the seam 17, as well as good strength
characteristics.
The fibrous layer 21 preferably comprises randomly oriented
individual fibrous filaments having a fiber length of at least 1
1/2 inches. A blend of synthetic fibrous components has been found
to be highly successful to provide the desired wear characteristics
and aesthetic properties, without detracting from the attributes of
the knitted base structure. Blends of acrylic, polypropylene, and
polyester fibers have been found particularly suitable, and a
preferred blend comprises 35 per cent by weight of 3 denier, 2 inch
staple acrylic fibers, 5 per cent by weight of 6 denier, 1 7/8 inch
staple polypropylene fibers, and 60 per cent by weight of 6 denier,
2 1/2 inch staple polyester fibers. The fibrous components of the
fabric preferably comprise between 30 and 40 per cent of the total
fibrous content of the fabric structure.
The preferred material provides not only competitive pricing of the
fabric, but also improved abrasion resistance, better formability,
improved soil resistance, reduced moisture absorbency when compared
to the conventional fabric cover of a woven hand napped
construction, all without impairing the bounce efficiency of the
core. Examination of the finished fabric shows a random orientation
of the fibers in the pile surface coupled with a high portion of
fibers disposed substantially perpendicular to the pile surface
penetrating through the layers composing the pile surface and the
base structure. The fiber segments which penetrate through the base
structure are looped around the yarn components in the base
structure and penetrate back through into the pile surface so that
the undersurface of the finished fabric does not exhibit any
substantial number severed ends of fibers but presents a
substantially smooth surface which is highly receptive to the
coating 16 of adhesive material used for applying the blanks to the
core.
The novel fabric of the present invention is produced by needling
webs of substantially untwisted fibers into the knitted base
structure with predetermined control of the thickness of the needle
and of the penetration of the needle into and through the composite
structure both in relation to the fabric construction of the base
structure. FIG. 6 illustrates a needling machine for producing the
novel fabric of the present invention, and FIGS. 7 through 10
illustrate needling operations which occur sequentially in the
production of the fabric in accordance with the present
invention.
As discussed above, the fibrous layer 21 of the fabric preferably
consists of a blend of synthetic fibers. In the preferred method of
producing the composite structure in accordance with the present
invention, the components of the layer 21 are blended in
conventional manner and in a final operation, are carded to produce
a loose fibrous bat. The bat is cross-lapped and is run through a
needle-tacker to give the carded web sufficient integrity to permit
handling thereof in the subsequent operations. The tacked web might
be produced with sufficient density and weight to be used alone as
a sole component of the fibrous layer 21, but is is preferred to
utilize a plurality of less-dense tacked webs in combination to
produce the desired weight of the layer 21 in relation to the base
structure 22. For the purpose of illustration, the relative
thicknesses of the layers 21 and 22 in the various stages of
production of the composite structure have not been reproduced in
the drawings.
It should be noted that the tacked webs used in the preferred
process of the present invention provide a lightly consolidated web
which is free from the dense consolidation of a thoroughly needled
structure so that the individual fibers within the lightly
consolidated web are free to be displaced through the structures
substantially independently of one another without bunching and
clumping. Thus it is preferred to use a plurality of lightly
consolidated webs and to build up the desired weight ratio between
the fibrous component and the knit component of the composite
structure by adding additional lightly consolidated webs until the
proper ratio is obtained.
Referring now to FIGS. 7 through 10, the function of the sequential
needling operations is illustrated diagrammatically therein.
In accordance with the invention, the fibrous web from the tacking
machine is initially united to the base structure by needling
operations which cause the barbed felting needles to enter
composite structure from the side of the layer 21 and penetrate
through the base structure 22. This needling function operates to
carry individual fibers of the layer 21 downwardly through both the
layer 21 and the base structure 22 and to project down beyond the
lower surface of the base structure 22. Repeated needling functions
operate to firmly interlock the layers 21 and 22 by the fibers from
the layer 21 which penetrate through the base structure 22. In
accordance with the invention, the coarseness of the needles 31
used in this needling function is selected relative to the openness
of the knitted construction in the base structure 22 so as to avoid
rupture of the yarns in the knitted structure by the barbs which
penetrate through the knitted structure as shown in FIG. 7. With
reference to FIG. 5, it is apparent that by selecting a needle with
a sufficiently fine diameter, it is possible to pass a barbed
needle through the knitted structure without tearing or otherwise
rupturing the yarns which compose the knitted structure. The fine
needles 31 used in the first needling function operate to carry
individual fibers downwardly through the composite structure so
that the fibers project below the undersurface of the
structure.
The next needling function operates to further integrate the
composite structure, and to this end the structure is needled from
the opposite surface again with fine needles. This is illustrated
in FIG. 8 wherein the composite structure has been reversed and
passed through the second needling operation utilizing identical
felting needles 31. The fine gage needles 31 penetrate the knitted
base structure without substantial rupture of the yarns in the
structure and the barbs of the needles 31 carry the fibers from the
undersurface (which is now uppermost) of the composite structure in
a reverse path through the structure. Obviously, the needles do not
retrace the identical path so that the fibers which previously
passed through one interstice of the knitted structure will in most
cases return through another interstice thereby forming a bight
which interlocks with the yarns of the knitted structure. The
reverse needling function is repeated until the undersurface (which
is uppermost) is substantially free of downwardly projecting fiber
ends and the knitted structure of the base layer 22 is predominant
on this surface.
The needling of the composite structure with the fine needles
effects a degree of consolidation of the lightly consolidated
tacked webs which are now integrated with he base structure;
however, for the end use of this fabric a denser consolidation of
the fiber structure is desirable. In order to obtain the denser
consolidation of the fibrous layer 21, coarser felting needles 41
have been found necessary. However, to avoid damage to the yarns of
the base structure 22, the depth of penetration of the heavier
needles 41 must be controlled to avoid the passage of the barbed
portion of the needles 41 through the knitted base structure. To
this end the fabric is again reversed so that the fibrous layer 21
is uppermost and the base structure 22 is lowermost. The composite
structure is passed through a needling operation wherein the
heavier needles 41 are caused to penetrate downwardly into the
fibrous layer 21 of the composite structure without penetrating
sufficiently far to cause the barbs to engage in the knitted base
structure 22 (see FIG. 9). In this manner, damage to the structure
by the barbs of the needles 41 is avoided and the structural
integrity of the base structure is maintained. The needling
function with heavy needles 41 is repeated until the desired
consolidation of the fibrous layer 21 is obtained.
The consolidation of the fibrous layer 21 by the heavy needles 41
has a tendency in many constructions, depending upon the
characteristics of the components of the composite structure
produced by the present invention, to produce needle marks or
tracking throughout the exposed pile surface 18 of the composite
pile fabric. To eliminate or mask the tracking or needle marks
produced in the previous needling functions, the present invention
provides a further needling function in which extremely fine
needles 51 are employed to erase the needle marks. In the present
instance, this needling function is performed with the base
structure 22 uppermost overlying the fibrous layer 22 and the
needles 51 are selected so as to be at least as fine as the needles
31 used in the first two needling functions. The finest gage
needles 51 serve to smooth out the exposed pile surface 18 and
furthermore tend to eliminate fuzz from the smooth undersurface 19
of the pile fabric structure. This smoothing function of the
needles 51 is accomplished without substantially affecting the
heavy consolidation of the fibrous material which was previously
accomplished by the heavy needles 41 and furthermore the finest
needles 51 avoid damage to the yarns of the base structure 22.
Although the needles of the final needling function are illustrated
as being finer than the needles of the first two functions, it is
possible to use the same thickness of needles for all of these
functions. Furthermore it is apparent that other variations will be
apparent to those skilled in this art, both as to the selection of
needles, and the selection of the components which make up the
layers 21 and 22. The correlation of the needle fineness to the
construction of the knitted base structure is paramount.
A specific example of the needling operations used and subsequent
finishing used to produce a fabric with the knitted base structure
indicated above has been performed on a Hunter Fiber-Locker
needling machine with 46-density needle boards and a feed of 15
strokes per inch. The needles for the first, second and final
needling function were No. 40 (15 .times. 18 .times. 40 .times.
31/2 RB felting needles) and the needles for the third needling
function were No. 32 (15 .times. 18 .times. 32 .times. 31/2 RB
felting needles). The fibrous layer 21 was needled to the base
structure 22 with No. 40 needles in two webs using three passes to
obtain adequate, even, overall fiber distribution and back
coverage. The fabric was reversed and was again needled with No. 40
needles for two passes until the back fiber coverage was returned
to the face side so that the knit cotton backing material was
clearly evident.
The machine was then adjusted to install the No. 32 needles and the
height of the needle board was adjusted to insure that no barbs
pierced the backing material. This needling was done for a
sufficient number of passes to obtain an overall thickness in the
range desired (0.145 inches to 0.155 inches) and the final needling
step was omitted.
The composite fabric was then scoured for 15 minutes at 212.degree.
F with detergent, and the water was extracted by running the fabric
through squeeze rolls. The fabric was tumble dried and then heat
set in open width on shelves in an oven at 350.degree. F. The heat
set fabric was then passed through squeeze rolls to reduce the
finished thickness to the desired range (0.110 inches to 0.120
inches). It should be noted that in this example the heat setting
in the oven was above the melting point of the polypropylene
component of the fibrous layer and it is believed that the heat
setting operation serves to provide a firm bond within the
integrated structure.
This composite fabric exhibited good formability when applied to
the cores of tennis balls both manually and in mechanized
operation. This was manifested by the absence of wrinkles and
puckering at the seams. Following vulcanization, the completed ball
was subjected to wear testing and the results of the test showed a
marked improvement in the wear characteristics of the completed
ball. The cover material does not ravel or fray at the seams. The
pile surface retains the pile for a period of use which is
substantially longer than the period of use considered acceptable
for balls made in accordance with the conventional prior art
processes.
Although the foregoing example utilized a weft-knitted two-layer
fabric base, it is anticipated that other knitted fabric
constructions may be embodied in a cover construction to obtain
results which are improved over the present conventional cover
construction. For example, warp-knitted fabrics may be substituted
and flat-knitted fabrics may be used in lieu of the circularly-knit
fabrics. Likewise the specific components of the fibrous layer set
forth above are not deemed to be restrictive, and as fiber
technology makes additional fibers available at economical costs,
such additional fibers may be substituted to provide properties
which are found desirable.
While a particular embodiment of the present invention has been
herein described and set forth in detail, it is not intended to
limit the invention to such disclosure but changes and
modifications may be made therein and thereto within the scope of
the following claims.
* * * * *