U.S. patent application number 10/266435 was filed with the patent office on 2003-06-05 for elongated pile sub-assembly, guide apparatus and pile sub-assembly articles of manufacture.
Invention is credited to Edwards, Mark S..
Application Number | 20030104161 10/266435 |
Document ID | / |
Family ID | 23315117 |
Filed Date | 2003-06-05 |
United States Patent
Application |
20030104161 |
Kind Code |
A1 |
Edwards, Mark S. |
June 5, 2003 |
Elongated pile sub-assembly, guide apparatus and pile sub-assembly
articles of manufacture
Abstract
An elongated pile sub-assembly having a support beam for
attachment to a plurality of yarn bundles. Each of the yarn bundles
attached to the beam have a pile end and a root end for anchoring
the elongated pile sub-assembly. The root ends can also entangle
its loose fibers for added anchoring support of the elongated pile
sub-assembly. A guide assembly is used to form a rooted tuftstring
article such as a brush or flooring article therefrom. The
elongated pile sub-assembly may be used alone to make a brush or a
pile or bristle surface structure such as a floor covering, a wall
covering or an automotive component, or may be arranged with other
elongated pile articles and attached to a backing substrate, as
when used to make up a pile or bristle surface structure. A brush
or pile surface structure may be fabricated from an elongated pile
sub-assembly alone, or from the pile sub-assembly together with a
brush body member or a backing substrate.
Inventors: |
Edwards, Mark S.;
(Hockessin, DE) |
Correspondence
Address: |
E I DU PONT DE NEMOURS AND COMPANY
LEGAL PATENT RECORDS CENTER
BARLEY MILL PLAZA 25/1128
4417 LANCASTER PIKE
WILMINGTON
DE
19805
US
|
Family ID: |
23315117 |
Appl. No.: |
10/266435 |
Filed: |
October 8, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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60336226 |
Oct 29, 2001 |
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Current U.S.
Class: |
428/85 ;
15/159.1; 15/182; 15/209.1; 15/230; 156/72; 300/2; 300/21; 428/88;
428/92 |
Current CPC
Class: |
Y10T 428/23929 20150401;
B29L 2031/42 20130101; D04D 5/00 20130101; Y10T 428/23957 20150401;
A46B 3/04 20130101; B29C 69/003 20130101 |
Class at
Publication: |
428/85 ; 300/21;
300/2; 15/182; 15/159.1; 15/209.1; 15/230; 428/88; 428/92;
156/72 |
International
Class: |
A46B 003/00 |
Claims
What is claimed is:
1. An elongated pile sub-assembly comprising: an elongated beam
having a longitudinal axis, a substantially uniform cross-sectional
size and shape, and a peripheral surface; and at least one bundle
of filaments being secured to the peripheral surface of the beam;
wherein the at least one bundle is secured to the beam at a
location along the length of the bundle that divides the length
into a longer bundle segment and a shorter bundle segment on either
side of the longitudinal axis, said longer bundle segment defining
a pile-forming tuft, and said shorter bundle segment defining an
anchoring segment.
2. An elongated pile sub-assembly, according to claim 1, wherein
the shorter bundle segment comprises shorter filament segments
3. An elongated pile sub-assembly according to claim 1, wherein the
shorter bundle segment anchors the elongated pile sub-assembly to a
substrate.
4. An elongated pile sub-assembly according to claim 3, wherein the
substrate comprises a woven material or non-woven material.
5. An elongated pile sub-assembly according to claim 3, wherein the
substrate is a material comprising a polymer, wood, metal or blends
thereof.
6. An elongated pile sub-assembly according to claim 5, wherein the
polymer comprises a thermoplastic, elastomer or thermoset
material.
7. An elongated pile sub-assembly according to claim 1, wherein the
length of the shorter bundle segment is about ninety percent or
less of the length of the longer bundle segment.
8. An elongated pile sub-assembly according to claim 7, wherein the
length of the shorter bundle segment is about five percent or less
of the length of the longer bundle segment.
9. An elongated pile sub-assembly according to claim 1, wherein the
beam has a width and the length of the shorter bundle segment is
greater than about 10% of the width of the beam.
10. An elongated pile sub-assembly according to claim 2, wherein
the shorter filament segments are substantially parallel with each
other.
11. An elongated pile sub-assembly according to claim 2, wherein a
plurality of shorter filament segments are substantially
perpendicular with a line that is tangent to or coincident with the
peripheral surface of the beam being parallelly adjacent to the
substrate.
12. An elongated pile sub-assembly according to claim 2, wherein
the shorter filament segments are deflected by the substrate having
resistance to penetration by the shorter filament segments.
13. An elongated pile sub-assembly according to claim 12, wherein
the shorter filament segments are substantially coplanar with the
substrate surface upon deflection from the substrate
resistance.
14. An elongated pile sub-assembly according to claim 12, wherein
the shorter filament segments are minimally deflected by resistance
from the substrate to penetration.
15. An elongated pile sub-assembly according to claim 12, wherein a
plurality of bundles of filaments being attached adjacently along a
length of the elongated beam, entangle shorter filament segments of
the adjacent plurality of bundles of filaments being deflected by
the substrate further anchoring the bundles of filaments to the
substrate.
16. An elongated pile sub-assembly according to claim 1, further
comprising a region along the length of each bundle of filaments
where filaments are densely packed together and bonded together,
the bundle being secured to the peripheral surface of the beam at
the densely-packed region wherein the peripheral surface is
perpendicular to the longitudinal axis.
17. An elongated pile sub-assembly according to claim 16, wherein
the filaments in at least one bundle form a yarn.
18. An elongated pile sub-assembly according to claim 1, wherein
the filaments are made from a thermoplastic polymer material.
19. An elongated pile sub-assembly according to claim 1, wherein
the beam is made from a material comprising thermoplastic
polymers.
20. A brush comprising: a first brush body member, and at least one
elongated pile sub-assembly, according to any one of claims 1-19,
secured to the first brush body member.
21. A brush according to claim 20, wherein the first brush body
member is substantially cylindrical.
22. A brush according to claim 20, wherein the first brush body
member is substantially planar.
23. A brush according to claim 20, further comprising a second
brush body member about which the first brush body member is
rotatable.
24. A brush according to claim 21, wherein the at least one
elongated pile sub-assembly is wrapped around the first brush body
member.
25. A brush according to claim 24, wherein the at least one
elongated pile sub-assembly is spirally wrapped around the first
brush body member.
26. A brush according to claim 20, further comprising a plurality
of bundles of filaments attached to said elongated beam being
secured to the first brush body member.
27. A brush according to claim 20, further comprising a plurality
of pile sub-assemblies in parallel alignment and secured to the
first brush body member.
28. A brush according to claim 20, wherein an at least one shorter
bundle segment of the elongated pile sub-assembly is secured to the
first brush body member.
29. A brush according to claim 28, wherein the shorter bundle
segment of the elongated pile sub-assembly is secured to a surface
of the first brush body member.
30. A brush according to claim 28, wherein the at least one shorter
bundle segment of the elongated pile sub-assembly is secured
beneath the surface of the first brush body member.
31. A brush according to claim 28, further comprising an adhesive
bond between the elongated pile sub-assembly and the first brush
body member.
32. A brush according to claim 31, wherein the adhesive bond is
located between one of the at least one shorter bundle segment or
the beam and the first brush body member.
33. A brush according to claim 20, wherein the at least one
elongated pile sub-assembly is secured to the first brush body
member by a zone of polymer flow.
34. A brush according to claim 33, wherein the shorter bundle
segment is located at a zone of polymer flow.
35. A brush according to claim 20, further comprising a fabric
including the at least one of the elongated pile sub-assembly, said
fabric being attached to the first brush body member.
36. A pile or bristle surface structure comprising: a substrate,
and at least one elongated pile sub-assembly, according to any one
of claims 1-19, secured to the substrate.
37. A surface structure according to claim 36, wherein the
substrate is flexible.
38. A surface structure according to claim 36, wherein the
substrate is rigid.
39. A surface structure according to claim 37 or 38, wherein the
substrate comprises a woven material or a non-woven material.
40. A surface structure according to claim 36, wherein the
substrate is a material comprising at least one of polymers,
natural fibers, metals, wood and blends thereof.
41. A surface structure according to claim 40, wherein the polymer
material comprises a thermoplastic, an elastomer or a thermoset
material.
42. A surface structure according to claim 36, further comprising a
plurality of the bundles of filaments attached adjacently to the
beam being secured to the substrate.
43. A surface structure according to claim 41, wherein a plurality
of the bundles of filaments attached adjacently along the beam
being aligned and parallel to one other.
44. A surface structure according to claim 36, wherein the
elongated pile sub-assembly is secured to the substrate by at least
one of the at least the shorter bundle segment and the beam.
45. A surface structure according to claim 36, wherein the at least
one shorter bundle segment of the elongated pile sub-assembly is
secured to a surface of the substrate.
46. A surface structure according to claim 45, wherein the at least
one shorter bundle segment of the elongated pile sub-assembly is
secured beneath the surface of the substrate.
47. A surface structure according to claim 36, further comprising
an adhesive bond between the elongated pile sub-assembly and the
substrate.
48. A surface structure according to claim 47, wherein the adhesive
bond being between at least one of the shorter bundle segment or
the beam and the substrate.
49. A surface structure according to claim 36, wherein the at least
one elongated pile sub-assembly is secured to the substrate by a
zone of polymer flow.
50. A surface structure according to claim 36, wherein the at least
one shorter bundle segment is located at a zone of polymer
flow.
51. A surface structure according to claim 36, wherein the at least
one elongated pile sub-assembly is secured to the substrate by
stitching.
52. A surface structure according to claim 36, wherein the at least
one elongated pile sub-assembly is secured to the substrate by a
hook and loop locking system.
53. A guide, comprising: at least one groove for selectively
guiding an at least one elongated pile sub-assembly according to
any one of claims 1-19, having an at least one short bundle segment
end, said short bundle segment end extending out of the same side
of the guide, and means for attaching the at least one shorter
bundle segment end to a substrate, wherein the guide is used to
join the at least one elongated pile sub-assembly to said
substrate.
54. A guide according to claim 53, wherein said attaching means
comprises one of a bonding agent, an ultrasonic device, a polymer
delivery system or stitching said shorter bundle segment to said
substrate.
55. A guide according to claim 54, wherein the bonding agent is an
adhesive material.
56. A guide according to claim 53, wherein said guide material
comprises a metal or polymer.
57. A method for joining an elongated pile sub-assembly to a
substrate using a guide, comprising: guiding the elongated pile
sub-assembly, according to any one of claims 1-19, through a groove
with the shorter bundle segment extending beyond the groove in said
guide; applying a bonding means to at least one of the substrate
and the shorter bundle segment; and securing the shorter bundle
segment extending beyond the groove to the substrate.
58. A method of claim 57, further comprising, between the applying
and securing steps, moving the substrate and the shorter bundle
segment into bonding contact with one another.
59. The method of claim 58, wherein said bonding means is a bonding
agent.
60. The method of claim 59, wherein said bonding agent comprises an
adhesive material being applied to at least one of the substrate or
plurality of shorter bundle segments along a beam.
61. The method of claim 57, wherein said bonding means comprises an
ultrasonic means comprising a force that presses the substrate and
the short bundle segment fibers into contact with each other and an
ultrasonic horn and an anvil, said anvil forming a rigid backing
creating a normal force for said ultrasonic horn having vibrational
energy bundle segment, the vibrational energy creating thermal
energy between the short bundle substrate contacting the substrate
and a beam of the elongated pile sub-assembly bonding the substrate
and the shorter bundle segment to one another.
62. The method of claim 57, wherein said bonding means comprises a
polymer melt delivery system.
63. The method of claim 62, wherein the polymer melt delivery
system comprises a polymer melt being delivered onto a surface of
said guide having a groove with said shorter bundle segments
extending outwardly therefrom.
64. The method of claim 63, wherein the polymer melt is solidified
containing the shorter bundle segments therein.
65. The method of claim 64, wherein the polymer melt is the
substrate.
66. The method of claim 63, wherein the polymer melt comprises a
thermoplastic, an elastomer or a thermoset material.
Description
[0001] This application claims the benefit of U.S. Provisional
Application No. 60/336,226, filed Oct. 29, 2001.
FIELD OF THE INVENTION
[0002] The present invention relates to an elongated pile
sub-assembly, pile sub-assembly articles and a guide apparatus that
is useful for the purpose of making a brush, or making a pile or
bristle surface structure such as a floor covering, a wall covering
or an automotive component. More particularly, the present
invention concerns an elongated pile sub-assembly have a "root" end
for secure anchoring of the elongated pile sub-assembly on or
through a substrate.
BACKGROUND OF THE INVENTION
[0003] The following disclosures may be relevant to various aspects
of the present invention and may be briefly summarized as
follows:
[0004] Conventional tuftstrings made from yarn are normally in a
"U" shape when attached or tufted into a backing substrate. The "U"
shape is formed when a yarn segment is attached to an elongated
strand near the medial point of the yarn segment. This "U" shape is
similar to that of a needle tufted yarn which also forms two
distinct and identifiable tufts from one yarn segment. This "U"
shaped tuftstring is disclosed in prior art such as WO 99/29949 to
Veenema et al., and U.S. Pat. No. 5,472,762 to Edwards et al.
[0005] A "U" shaped tuftstring for wall or floor coverings is
normally attached to a backing structure first, to form a pile
fabric or carpet. The point of attachment for the "U" shaped
tuftstring is at the bottom of the "U" shape, which is also where
the yarn and the support beam bond to one another. This bond area
is generally a solid mass of fibers fused together providing only a
small surface area to contact with and bond to a support substrate.
The bond between the "U" shaped tuftstring can be formed using a
thermal or solvent fusing process, adhesives, or mechanical
interlocking means. This small contact area generally produces low
"tuft-lock" values (e.g. the force at which the bond fails).
Additionally, the rounded bottom of the "U" is susceptible to
rotation (see FIGS. 1B and 1C) which can cause undesirable visible
defects. FIG. 1C shows one example of the effect of such rotation
on a "U" shaped tuftstring. The bottom of the "U" tips or tilts to
one side when aligned with a ridgeline 105a on the surface of a
substrate 105 having an embedded reinforcement fiber. This form of
rotation causes density variations in the finished product. Another
example of "U" shaped tuftstring rotation is the undesirable
visible defect that occurs when the tufts on one side of the "U"
have a higher frictional drag than the opposite side tuft during
the insertion/bonding process causing the tuftstring to pivot
laterally (see FIG. 1B). When this occurs, one row of tufts
effectively becomes longer while the other row is effectively
shortened by the same incremental length. These linear variations
or visible defects are referred to as "rowiness".
[0006] Additionally, when an adhesive is used for attaching the "U"
shape to a substrate, the top surface of the adhesive is generally
above the reference plane 300 of FIG. 5B and thus, an unwanted,
performance altering (e.g. reduction in the softness of the pile)
wicking of the adhesive into the tuft may occur.
[0007] Another disadvantage of the "U" shaped tuftstring, is that
the two yarn ends of the "U" shaped tuftstring have a sizable gap
between them when manufactured. This gap is reduced when the
tuftstring is positioned in close proximity to other tuftstrings
due to compression or interference with other tufts from adjacent
tuftstrings. However, this compression or interference may be
another source of density variations as some of the pile filaments
may be separated such that they are all not in vertical alignment.
Some filaments are directed toward the substrate and bonded thereto
or otherwise entangled such that they are not a part of the desired
pile density.
[0008] U.S. Pat. No. 5,470,629 to Mokhtar et al. describes making
pile "tuftstrings" where each tuftstring is made by wrapping yarn
around a mandrel on which a support strand is translated. As the
support strand moves, it transports "wraps" of yarn to an
ultrasonic welder which connects the wraps to the support strand.
The bonded wraps are further transported to a slitter station which
cuts the wraps and thereby forms the tuftstring. The tuftstring
includes two rows of upstanding legs or tufts which are attached at
their bases to the support strand. The yarn of Mokhtar et al. is a
multifilament, crimped, bulky yarn that is made preferably of a
thermoplastic polymer, such as nylon or polypropylene. The support
strand is likewise preferably a thermoplastic polymer so that, when
passed under the ultrasonic welder, the yarn and support strand
melt to form a bond therebetween.
[0009] It is desirable to have an elongated pile sub-assembly that
has a high "tuft-lock" value, controlled wicking and vertical
alignment. There is also a need for a low-cost elongated pile
sub-assembly, containing bundles of fibers arranged to provide a
high density, that can be made by a simple, inexpensive method, and
is designed to be packaged, or used directly as a feed material for
making a brush or a pile/bristle surface structure. There is also a
need for a strong, reliable elongated pile sub-assembly that can be
packaged and handled in a fabrication process. It is also desirable
to have a guide apparatus to bond the elongated pile sub-assembly
to a substrate.
SUMMARY OF THE INVENTION
[0010] The elongated pile sub-assembly of this invention includes a
continuous length support beam having a longitudinal axis, a
uniform or substantially uniform cross-sectional size and shape, a
peripheral surface, a reference plane tangent to or coincident with
a location on the surface of the support beam, and a plurality of
bundles of filaments secured to the support beam. The filament
bundles have long bundle segment ends opposite the short bundle
segment ends. The filaments on an end of at least one bundle (e.g.
the long bundle segment ends) define a pile-forming tuft. There is
a region in each bundle in which the filaments are densely-packed
together and are generally bonded together, and the bundle is
preferably secured to the support beam at the location of the
densely-packed region.
[0011] Briefly stated, and in accordance with one aspect of the
present invention, there is provided an elongated pile sub-assembly
comprising: an elongated beam having a longitudinal axis, a
substantially uniform cross-sectional size and shape, and a
peripheral surface; and at least one bundle of filaments being
secured to the peripheral surface of the beam; wherein the at least
one bundle is secured to the beam at a location along the length of
the bundle that divides the length into a longer bundle segment and
a shorter bundle segment on either side of the longitudinal axis,
said longer bundle segment defining a pile-forming tuft.
[0012] Pursuant to another aspect of the present invention, there
is a brush comprising: a first brush body member, and at least one
elongated pile sub-assembly secured to the first brush body
member.
[0013] Pursuant to another aspect of the present invention, there
is a pile or bristle surface structure comprising: a substrate, and
an elongated pile sub-assembly secured to the substrate.
[0014] Pursuant to another aspect of the present invention, there
is a guide, comprising: a groove for holding an at least one
elongated pile sub-assembly according to any one of claims 1-19,
having an at least one short bundle segment end, said short bundle
segment end extending out of the same side of the guide as the
groove, and means for attaching the at least one shorter bundle
segment end to a substrate, wherein the guide is used to join the
at least one elongated pile sub-assembly to said substrate.
[0015] Pursuant to another aspect of the present invention, there
is a method for joining an elongated pile sub-assembly to a
substrate using a guide, comprising: guiding the elongated pile
sub-assembly through a groove with the shorter bundle segment
extending externally beyond the groove in said guide; applying a
bonding means to at least one of the substrate and the shorter
bundle segment; moving the substrate and the shorter bundle segment
into bonding contact with one another; and securing the shorter
bundle segment extending beyond the groove to the substrate.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The invention will be more fully understood from the
following detailed description, taken in connection with the
accompanying drawings, in which:
[0017] FIG. 1A shows the prior art of a conventional "U" shaped
tuftstring;
[0018] FIGS. 1B and 1C are elevational end views of the prior art
showing visible defects resulting from "U" shaped tuftstring
rotation;
[0019] FIG. 2B shows a rooted tuftstring of the present
invention;
[0020] FIGS. 2A, 3A, and 4 are elevational end views of the
elongated pile sub-assembly of the present invention showing
different "root" end penetration;
[0021] FIG. 3B shows elevational end views of a plurality of rooted
tuftstrings shown in FIG. 3A with the entanglement of the rooted
filaments;
[0022] FIG. 5A is a perspective view of an elongated pile
sub-assembly of the present invention;
[0023] FIG. 5B is a prior art perspective view of an elongated "U"
shaped tuftstring;
[0024] FIG. 6 is a diagram showing one way to measure the diameter
of a pile yarn;
[0025] FIG. 7 is a simplified representation of a section along the
center of an elongated pile sub-assembly support beam showing tufts
bonded to the beam in a single layer with the "roots" extending
below;
[0026] FIG. 8 is a simplified representation of a section along the
center of a rooted tuftstring support beam showing bundles bonded
to the beam in an overlapping relationship;
[0027] FIG. 9A is a diagrammatic view of a simple process for
making the elongated pile article of the present invention;
[0028] FIG. 9B is an end view of FIG. 9A showing a second
slitter;
[0029] FIG. 10 is a side elevational view of a paint roller pile
assembly using the present invention;
[0030] FIG. 11 is an end view of the paint roller of FIG. 10;
[0031] FIG. 12 is an end elevational view of an embodiment of a
plurality of elongated pile sub-assemblies;
[0032] FIG. 13 is an end elevational view of an embodiment of an
elongated pile sub-assembly bonded using an ultrasonic weld;
[0033] FIG. 14 is an end elevational view of a plurality of
elongated pile sub-assemblies of the present invention attached via
adhesive pile tape to a core;
[0034] FIG. 15 is a diagramatic illustration of a method of making
a pile or bristle surface structure from elongated pile
sub-assemblies of this invention;
[0035] FIG. 16 is a schematic illustration of a guide used in
attaching or bonding elongated pile sub-assemblies of the present
invention to a backing substrate or bonding material;
[0036] FIG. 17 is a schematic illustration of an elongated pile
sub-assembly guide for bonding with flexible materials; and
[0037] FIG. 18A and FIG. 18B show elevational views of two
embodiments of an ultrasonic horn used for bonding in the present
invention.
DETAILED DESCRIPTION OF THE INVENTION
Definition of Terms
[0038] The following definitions are provided as reference in
accordance with how they are used in the context of this
specification and the accompanying claims:
[0039] 1. Beam or Base String: A strand, string or cord composed of
one or more materials and having one or more separate structural
components, each having its own defined and identifiable shape. The
beam or base string provides connectivity and support to tufts
attached thereto.
[0040] 2. Bristle: A short stiff fiber segment natural or man-made
generally referred to as in diameters measured in thousandths of an
inch.
[0041] 3. BCF or BCF Yarn: bulk continuous filament yarn; a
textured continuous-filament yarn, generally used either as a pile
yarn in carpets or for upholstery fabrics.
[0042] 4. Tuftstring: A beam having attached to it at least one
segment of yarn consisting of one or more filaments each having a
diameter such that the diameter is reported in units of denier
rather than thousandths of an inch (mils).
[0043] 5. Rooted Tuftstring or Elongated Pile Sub-Assembly: A
Tuftstring where the beam or base string divides the long bundle
segments from the short bundles segments. The short bundle segments
also called "roots" are the non-bonded yarn fiber that attaches the
tuftstring to substrates (i.e. other articles or base materials).
The long bundle segments are the non-bonded yarn fiber end that
forms the pile or bristle end of the tuftstring.
[0044] 6. Denier: The mass in grams of 9000 meters of a fiber,
filament, or yarn.
[0045] 7. Fiber: Textile raw material, generally characterized by
flexibility, fineness and high ratio of length to thickness.
[0046] 8. Filament: A fiber of indefinite length.
[0047] 9. Filament Yarn: Normally continuous filament. A yarn
composed of one or more filaments measured in denier units that run
essentially the whole length of the yarn.
[0048] 10. Yarn: A product of substantial length and relatively
small cross-section consisting of fibers and/or filaments with or
without twist.
[0049] The rooted tuftstring of this invention may be understood
from a general description of a method by which it may be produced.
This method involves: feeding a continuous length of a bundle of
filaments under tension along the center of rotation of an
eccentric guide; rotating the guide to wrap the bundle of filaments
around a support having a plurality of elongated ridges to form a
succession of wraps or flights of the continuous length of a bundle
of filaments that envelope the support; feeding a continuous strand
of material along at least one of the ridges on the support,
between the support and the flights of the bundle of filaments
formed by the step of wrapping, to provide a beam; bonding the
filaments in the bundle to each other and securing the bundle of
filaments to the beam; cutting the flights of the bundle of
filaments to form an elongated pile sub-assembly; and forwarding
the elongated pile sub-assembly for further processing. Reference
is made to U.S. Pat. No. 5,547,732, WO 99/29949, and U.S. Pat. No.
5,498,459 whose contents are herein incorporated by reference as
examples of the above method of forming a "U" shaped tuftstring. In
the present invention, however, the above prior art references are
differentiated from the present invention in the cutting step to
produce the rooted tuftstring. A distinguishing difference, in the
present invention, is the position of the rotating slitter knives
relative to the bonded beam (e.g. base string). In the above
referenced patents, the slitters are positioned so as to form two
tufts of substantially equal length from one continuous yarn
segment. In the present invention, the slitters, or the bonding
position of the beam, or both are repositioned so as to produce a
tuftstring with a first bundle of filaments segment for use as the
pile surface and a second bundle of filaments segment for use in
anchoring the tuftstring to a fabric or other support structure,
such that the first segment is generally longer than the second
segment. (See FIGS. 9A and 9B). The above references are examples
of machine methods capable of producing tuftstrings with the
modified cutting step but are not all-inclusive. There are a
variety of machine methods that are applicable to producing the
rooted tuftstring of the present invention.
[0050] In the "U" shaped tuftstring (see FIG. 1A) the bundle of
filaments is cut such that the base string 101 is substantially
equidistant from the cut end of each bundle segment of the
tuftstring 108. In FIG. 1A, the "U" shaped tuftstring 108 has an
equal bundle segment length 109a and 109b on either side of the
base string 101. The tuftstring 108 is bonded to the adhesive
backing 107 at the six o'clock position 101a. A disadvantage of the
"U" shaped tuftstring approach is that the bundle segment lengths
109a and 109b can appear to be uneven when assembled with other "U"
shaped tuftstrings (See 1B and 1C). This can occur in a variety of
ways. For example, the base portion of the "U" shaped tuftstring
may roll or rotate as it is guided and secured to the backing. More
friction on one bundle segment 109b than on bundle segment 109a,
for example, would generate a torque and cause the "U" shaped
tuftstring to rotate counter clockwise as shown by arrow 103a (see
FIG. 1B). Another cause can be attributed to an uneven substrate
surface such as when a reinforcement fiber is present and generates
a ridgeline 105a on the surface. Referring to FIG. 1C, when first
side 109a of the "U" shaped tuftstring contacts the substrate
surface before second side 109b, a torque force is again
established when the velocity or motion is normal to the plane of
the substrate and can cause the tuftstring to rotate or lean. The
leaning effect shown in FIG. 1C, can also cause a space 132 between
the tufts which creates an undesirable spacing defect or at least
causes density variations in the finished pile.
[0051] The present invention (see FIGS. 2A, 2B, 3A, and 4) utilizes
a modified tuftstring that improves the bond strength between the
tuftstring and the substrate fused to bind multiple tuftstrings
together (for example, as in a carpet), especially when adhesives
are used as the bonding agent. Thus, eliminating the need in the
present invention (e.g. one long bundle of fibers segment side 126
and one short bundle of fibers segment side 127, 128, 129) to fold
the yarn tufts into a conventional "U" formation. The long bundle
segments 126 are arranged together as a continuous row of long
bundle segments in the proper orientation for functional value,
while the short bundle segments 127, 128, or 129 are used to anchor
the elongated pile sub-assemblies 125 to the backing substrate with
the aid of an adhesive or other means, such as ultrasonic bonding
or solvent bonding.
[0052] In the present invention, the yarn used in the elongated
pile sub-assembly 125 (see FIG. 2A) is a multifilament strand where
the filaments are typically "connected" to one another. The
filaments are "connected" in that they may be twisted at a level of
at least about 1 turn/inch to provide filament crossovers that
enhance bonding (especially ultrasonic bonding), or the filaments
may be interlaced to provide crossovers. The yarn may also comprise
two or more strands of multifilaments that are ply-twisted
together. The ply-twisting may be a "true" S or Z strand and ply
twist, or a reverse twist where the S and Z strand and ply twist
alternate and there is a bond in the ply and strand twist reversal.
Preferably the reverse twisted yarn has a bond in the plied yarn
before reversing the twist, as described in U.S. Pat. No.
5,012,636. One such yarn is preferably made from crimped, bulky,
heat-treated filaments and is commonly used as carpet yarns. The
filaments of the yarn may have a variety of cross-sections which
may be hollow and contain antistatic agents or the like. The yarn
may have a finish applied that aids in ultrasonic bonding. The yarn
may in certain preferred embodiments be a multifilament, crimped,
bulky, ply-twisted yarn that has been heat set to retain the
ply-twist.
[0053] In other applications where a velour surface is preferred,
such as in automotive flooring and paint rollers, another type of
yarn is preferred. Such a yarn includes one in which the
multifilaments of the BCF yarn are loosely entangled and are not
heat treated. For automotive or other transportation use, the
rooted tuftstring (i.e. elongated pile sub-assembly) preferably
made of BCF singles yarn, that is not twisted, ply-twisted, or
otherwise entangled to form individual long bundle segments as
described in WO 99/29949.
[0054] When using ultrasonic bonding means to form the rooted
tuftstring, the yarn, (preferably made from a thermoplastic polymer
having the same composition as the beam,) achieves high bond
strength of the yarn bundles to the beam. In some ultrasonic
bonding applications, the yarn and the beam can be of different
compositions and still achieve adequate bonding between the two.
One such example is a nylon yarn bonded to a polypropylene beam. It
is further noted that in bonding methods other than ultrasonic
bonding, using the same composition for beam and yarn provide high
bond strength and avoid the need for adhesives. However, adequate
bonding of different compositions for the yarn and beam in bonding
methods other than ultrasonic are also adequate.
[0055] When using an adhesive method to bond the yarn to the beam,
the composition of the yarn and the beam is selected according to
the range of suitable materials the adhesive can bond with or, the
adhesive is selected according to the selection of yarn and beam
composition. It is important that the bond between the yarn and the
beam be adequate to deliver the yarn to the support structure
without loss of yarn segments or individual fibers from a yarn
segment. Once the short segment fibers are bonded to the substrate,
the bond strength between the beam and the yarn bundles becomes
less significant.
[0056] In the present invention, the yarn is typically a
thermoplastic polymer such as a polyamide, a polyolefin such as
polyethylene or polypropylene, a polyester, a fluoropolymer,
polyurethane, polyvinylchloride, polyvinylidene chloride, or a
styrenic polymer or copolymer, including mixtures of two or more
thereof, and the like. Polypropylene; or a polyamide such as nylon
6; nylon 11; nylon 6,6; nylon 6,10; nylon 10,10; and nylon 6,12 is
preferred. The yarn may alternatively be a poly (aryletherketone)
or a polyaramid or meta-aramid that is bondable with solvents,
ultrasonics, or heat.
[0057] The beam useful in the elongated pile sub-assembly may have
a variety of cross-sectional shapes, such as square, rectangular,
elliptical, oblong, round, triangular, multi-lobal, flat
ribbon-like, etc. The beam must be bondable to the yarn and have
sufficient elongational stability so the bonds are not
over-stressed due to stretching of the beam or its tensile strength
exceeded. The beam must provide sufficient stability to the pile
sub-assembly such that it can be handled for its intended use, such
as manufacturing a brush or manufacturing floor covering articles,
such as a carpet or rug. The beam may be a monofilament, a
composite structure, a sheath/core structure, a reinforced
structure, or a twisted multifilament structure. The beam is
preferably made from a thermoplastic polymer so the yarn beam can
be bonded without use of adhesives. The beam is more preferably a
polymer having a molecular structure oriented in the elongated
direction, and having a low dimensional change in the direction of
orientation due to moisture gain or loss or modest temperature
changes. One material for use as the support beam is a monofilament
nylon polymer, such as Tynex.RTM. made by E. I. du Pont de Nemours
and Company. Other materials for use as the support beam include
polypropylene and polyethylene. In some applications, one or more
of the polymers named above can be combined, such as in coextrusion
to form a bi-component beam.
[0058] Filament production may be accomplished by the use of an
extruder, many varieties of which, such as a twin-screw extruder,
are available from manufacturers such as Werner and Pfleiderer. A
polymer in the form of granules is fed from a feeder unit into the
extruder either volumetrically or gravimetrically. A slip agent is
fed from a separate feeder into the extruder through a side-arm
port, and is blended with the polymer in the extruder at a
temperature of 150-285.degree. C. Alternatively, the slip agent can
be pre-compounded or pre-blended with the polymer so that a
separate feed system is not required. The polymer and slip agent
are mixed as a melt in the extruder, and the resulting composition
is then metered to a spin pack having a die plate. The composition
is filtered, and filaments of various shapes and sizes are produced
by extrusion through the holes in the die plate.
[0059] Similar to the support beam discussed above, the filaments
from which the bundle of filaments is prepared may have a variety
of cross-sectional shapes, as determined, for example, by the shape
of the die plate orifice when production is by extrusion. The
shapes include but are not limited to round, oval, rectangular,
triangular, or the shape of any regular polygon; or the filament or
beam (discussed above) may be an irregular, non-circular shape.
Additionally, the filament or beam may be solid, hollow or contain
multiple longitudinal voids in its cross sections. Each run of an
extruder can produce any combination of cross-sectional shapes by
using a die plate with various shaped holes. Filaments or beams of
one or more diameters may be made at the same time by varying the
size of the holes in the die plate. Alternatively, the filament
and/or beam used in this invention may be produced by solution
spinning.
[0060] Another aspect of this invention involves the use of a
filament and/or beam having a sheath/core construction. The sheath
surrounds the core in a coaxial or concentric configuration. The
polymer used in the core and the sheath may be the same or
different. When dissimilar polymers are used, the properties of the
polymers must be such that they can be co-extruded, drawn to
diameter and wound onto spools. Nylon 6,6 is preferred as a sheath
material. A sheath/core filament or beam is typically produced by
coextrusion using two extruders sharing a common spin pack. The
polymer used to make the core is channeled from a first extruder to
the center of the spin plate holes, and the composition used to
make the sheath is channeled from a second extruder to the outside
of the spin plate holes.
[0061] A sheath/core filament of yarn, or a beam in filament form,
which is produced from more than one source of flowable polymer or
polymeric composition, as described above, may be distinguished
from a filament that is produced from a single source of flowable
polymeric composition. Such a single-source filament may be
referred to as a single composition monofilament. For a beam, the
filament used in the present invention may be either a
multi-component or a single component monofilament, with a single
component monofilament being preferred.
[0062] A filament for use in the bundle of filaments in this
invention has a diameter, or maximum cross-sectional dimension, as
determined by the diameter of the smallest circle in which it is
circumscribed, of about one or more, preferably about two or more,
and most preferably about 2.5 or more, and yet about 15 or less,
preferably about 10 or less, and more preferably about 5 or less,
mils. (A mil is 0.025 mm.)
[0063] A filament or beam for use in this invention may be prepared
from a polymeric composition as described above containing typical
additives such as fillers, colorants, stabilizers, plasticizers or
anti-oxidants, or a mixture of more than one thereof; or may be
prepared with a surface coating.
[0064] Reference is now made to FIGS. 2A.about.4 which show
different end views and encapsulation embodiments of the "root" end
of an elongated pile sub-assembly, or rooted tuftstring 125 of the
present invention. FIG. 2 shows an end elevational view of an
elongated pile sub-assembly with the short filament bundle segment
127 penetrating the adhesive 117 and backing substrate 115. FIG. 3A
shows an end elevational view of an elongated pile sub-assembly
with the short filament bundle segment 127 having a flared
penetration 128 of the adhesive 117 and the backing substrate 115.
FIG. 4 shows an end elevational view of an elongated pile
sub-assembly with the short filament bundle segment 127 having
surface flaring 129 in the adhesive 117. In FIGS. 2A.about.4 the
short filament bundle fibers are totally encapsulated for a strong
anchoring of the elongated pile assembly 125. Another variation,
not shown, is where all the roots 127 of FIG. 2 lay horizontally to
one side.
[0065] With continuing reference to FIGS. 2A.about.4, the ultimate
position of the roots of the tuftstring is mostly dependent on the
characteristics of the substrate and the stiffness of the root
filaments. An open, non-woven substrate would easily permit the
roots to penetrate the fabric structure without much deflection of
the roots as shown in FIG. 2A. Tightly woven fabrics offer more
resistance and deflect more of the roots upon entry into the fabric
as depicted in FIGS. 3A and 3B. A highly dense non-woven fabric,
like Tyvek.RTM. or a solid sheet, such as an extruded thermoplastic
structure would prevent penetration by the filament roots into the
substrate structure causing complete deflection 129 of the short
segment fibers 127 as shown in FIG. 4.
[0066] Referring now to FIG. 5A which shows a plurality of bundles
of filaments 154, as yarn that has been secured to a support beam
119 at a location 73 on the peripheral surface thereof. The longer
bundle segment 126 of the elongated pile sub-assembly 125 defines a
pile-forming tuft. The shorter bundle segment 127 of the elongated
pile sub-assembly 125 defines the root forming tuft.
[0067] Referring now to FIG. 2A which shows the elongated pile
sub-assembly 125. The bundle of filaments 154 is bonded to the beam
119 to form the elongated pile sub-assembly. The bundles of
filaments 154 has, along its length, a densely-packed region 162
where the filaments are generally bonded together, and which is the
location where the bundle is secured to the support beam 119.
[0068] Referring again to FIG. 5A, a support beam 119 has a
uniform, or substantially uniform, cross-sectional size and shape,
and a peripheral surface 133. The densely-packed region 162 (FIGS.
2A.about.4) along the length of the elongated pile sub-assembly 154
where the filaments are bonded together is secured to the
peripheral surface 133 of the support beam 119 parallel and
adjacent thereto. The bundle of filaments 154 is secured to the
peripheral surface 133 (perpendicular to the reference plane 71) of
the beam across all, or across a substantial portion of, the
densely-packed region 162. Contained within the bundle of filaments
154 are filaments that are substantially linear, and thus have
opposing ends 202 and 204. The opposing ends of the filaments
define a length of the bundle. The bundle 154 is secured to the
beam at a location along the length of the bundle that divides the
length into a longer bundle segment 126, which has a longer length,
and a shorter bundle segment 127, which has a shorter length, on
either side of the longitudinal axis 140 of the beam 119.
[0069] The longer bundle segment 126 contains longer filament
segments, and the length of the longer bundle segment is measured
from the location that divides the filament bundle 154 into longer
and shorter bundle segments to the end 202 of the longer filament
segment contained in the longer bundle segment. The longer bundle
segment 126 is pile-forming at the cut ends 202 of the longer
filament segments. The shorter bundle segment 127, contains shorter
filament segments, and the length of the shorter bundle segment is
measured from the location that divides the filament bundle into
longer and shorter bundle segments to the end 204 of the shorter
filament segments. The usable portion of the longer bundle segment
126 and the shorter bundle segment 127 are on opposite sides of the
densely packed region of the filament bundle 125. The shorter
filament segments define "roots" that have substantial utility in
anchoring the tuft particularly when the pile sub-assembly is used
to make a brush, pile surface structure or other articles, as
described herein.
[0070] The length of the shorter bundle segment 127 (FIG. 2A) is
preferably about 90 percent or less than the length of the longer
bundle segment 126. In other embodiments, however, the length of
the shorter bundle segment may, as desired, be about 75 percent or
less, about 50 percent or less, about 25 percent or less, about 10
percent or less, or about 5 percent or less, than the length of the
longer bundle segment. The length of the shorter bundle segment
preferably exceeds about 10 percent of the width of the beam. For
example, if the beam width is 200 mil then the roots need to be
longer than 20 mils. (It is further noted that the longer the short
bundle segment 127 when attached to the substrate, the more secure
the anchoring of the elongated pile sub-assembly 125). The width of
the beam is defined as the smallest of the following quantities:
(i) the distance across the cross-sectional area of the beam 74, as
shown, for example, in FIG. 5A, measured through and perpendicular
to the longitudinal axis of the beam and parallel to the reference
plane 71; (ii) the diameter of the smallest circle that completely
circumscribes the cross-sectional area of the beam; or (iii) in the
case of a cross-sectional area of the beam that is a true
rectangle, the longer of the two dimensions of the rectangle. In
further embodiments, however, the length of the shorter bundle
segment may, as desired, exceed about 55%, about 60%, about 75%, or
about 100% of the width of the beam.
[0071] Six test samples of rooted tuftstring were tested for
anchoring strength using an Instron (Model #1125). The rooted
tuftstring samples were 1.00" long having a short segment length of
0.090 inches and a long segment length of 0.265 inches. Two test
cells, repeatedly used, were fabricated having the following cavity
dimensions: 1.00" long by 0.185" wide and 0.25" deep to receive an
adhesive. A hot melt adhesive of Profax Polypropylene PF611 CT
distributed by the H. A. Hanna Company was used. The test cell was
heated and filled with the Profax Polypropylene PF611 CT adhesive.
The rooted tuftstring sample was placed into the test cell such
that the short segment fibers only were subsurface in the adhesive
melt. The rooted tuftstring, adhesive and cell were then allowed to
cool to room temperature before testing for anchoring strength. The
Instron clamping device was fastened to the test cell and another
to the long segment fibers of the rooted tuftstring. The Instron
test instrument was used to detect the peak force applied to the
clamps at the moment of failure of the roots. The goal of these
tests was for the rooted tuftstrings to have an anchor strength
greater than 15 lbs. In test after test, there was no failure
observed of the bond between the short segment fibers and the solid
adhesive resin within the test cell. The type of failures observed
were: 1) between the adhesive and the test cell walls which were
the most common failures; and 2) the remaining failures were the
yarn fibers that failed in the vicinity of the bond between the
yarn fibers and the beam. All failures of the adhesive to the test
cell and of the yarn fibers occurred at tensions exceeding 45
pounds. These results far exceeded the minimum desired goal of 15
pounds.
[0072] It is important to realize that the "roots" of each yarn
bundle are in a three dimensional space when anchored into a
substrate. For example, FIG. 4 shows the roots spread to the left
or right of the bundle vertical center in this end view. While this
orientation 129 of the short bundle segments 127 can occur, they
are more likely spread 360 degrees from the vertical center of the
bundle 125 within a plane parallel to and a plane below the
reference plane 71 of FIG. 5A. In FIGS. 2B and 3A, the roots are
spread in a cone shape below the reference plane 71 (FIG. 5A), each
having a center vertical axis generally tangent to or coincident
with the yarn bundle side vertical peripheral surface of the beam.
FIG. 2B is a narrow cone, while FIG. 3A is more hemispherical.
[0073] In an embodiment of the present invention, FIG. 5A shows the
elongated pile sub-assembly in which the bundle of filaments is
secured to the support beam 119, which may be accomplished by
ultrasonic bonding or other means. The filaments of the short
bundle segment 127 are used as the anchoring point of the elongated
pile sub-assembly 125. By comparison, the "U" shaped tuftstring of
the prior art, utilizes the dense portion 101a (see FIG. 1A) of the
filament bundle and the bond line formed between the support strand
and the yarn bundles as the anchoring surface. This area has the
characteristics of a solid mass, and as such, the only surfaces
available for an adhesive to connect with, are the outer peripheral
surfaces of the yarn/strand mass. This is a limiting characteristic
of the prior "U" shaped art. By contrast, the short bundle segments
127 (FIG. 2B) of the present invention, have substantial surface
area due to the "roots" (e.g. fibers of the short bundle segments)
it provides to anchor the filament bundle in an adhesive media 117.
In the present invention, the roots are filament segments that are
continuous with and extending in the opposite direction of the pile
forming filament segments. The proximal end of the short filament
segments or roots are bonded to the beam and are thus fixed in
position and have limited surface area in that regard. However, the
remaining length of the short filament segment roots can and do
provide considerable surface area. In the simplest case where the
cross-section of the filaments is round, the surface area is simply
the surface area of a cylinder.
[0074] Comparison by example of the surface area of the "U" shaped
tuftstring to that of a rooted tuftstring of the present invention,
clearly shows the benefit of the present invention. For example,
when using a 28 mil beam and a 1500 denier, two-ply yarn bonded to
the beam to form both a "U" shaped tuftstring and a rooted
tuftstring, the adhesive bonding surface area of the "U" shaped
tuftstring is 0.060 square inches per inch of tuftstring whereas
for a rooted tuftstring, having a 0.063 inch length of short
segment fibers and eleven (11) tufts per inch, it is found that the
surface area is 0.864 square inches per inch of tuftstring. This is
a 1,340 percent increase in available surface area for the adhesive
to bond with.
[0075] In addition, these unconstrained distal filament ends of the
short segment fibers can interact and entangle 121 with the
(fibrous) structure of the substrate as shown in FIG. 3B for added
anchoring strength. The fibrous "roots" of the present invention
are encapsulated and mechanically locked into the adhesive media
when it freezes. This mechanical bond replaces the need for a
strong chemical or thermal bond to anchor the tuftstring to a
support substrate and therefore greatly expands the opportunity to
use lower cost, and environmentally friendly adhesives.
[0076] Referring to FIGS. 2B.about.4, the filaments of the short
bundle segment 127 act as a wick and draws the adhesive into the
void spaces between the filaments generating a matrix structure
such as found in resin composite structures. The dense portion of
the filament 162 limits the travel of the adhesive from migrating
up into the long bundle segment 126 by forming a barrier zone. In
this embodiment, the opposing ends 202, 204 of the filaments define
a length of the bundle. This bundle has longer and shorter bundle
segments, characteristics related to the length of the longer and
shorter bundle segments, and varied orientation 128, 129 of the
shorter filament segments when attached to a support substrate, as
described above.
[0077] Where yarns with strong interconnections among the filaments
are used, it may be preferable to "comb out" the short segment
portion of the rooted tuftstring so that filament to filament
entanglement is minimized to permit the short segment fibers to
better disperse into the adhesive and support substrate.
[0078] A further characteristic of the bundle of filaments utilized
in the elongated pile sub-assembly of this invention is that (1) at
least one bundle is divided into (a) a first segment, comprising
first filament segments, on one side of the location at which the
bundle is secured to the beam, having a first stiffness, and (b) a
second segment, comprising second filament segments, on the other
side of said location, having a second stiffness. The change in
stiffness of a filament is proportional to the fourth power of the
effective cross-sectional area and to a third power of the length.
Thus for a given diameter, the relative stiffness will decrease by
87.5% when the unrestrained length is doubled, assuming no
interactions with adjacent filaments. Therefore the stiffness of
the short segment bundle can be slightly higher or orders of
magnitude stiffer than the longer segment bundles depending solely
on the ratio of length.
[0079] Depending upon the product to be made from rooted
tuftstring, the length of the short segment is selected based on
these characteristics such as stiffness and anchoring strength to
the substrate. Longer short segment fibers have reduced stiffness
and therefore will be more likely to "mat" down such as in FIG. 4.
Shorter short segment fibers will be stiffer and have a greater
potential for puncturing the surface plane of the support substrate
such as shown in FIG. 2. As expressed earlier, the denier of the
fiber filaments also influences the extent to which fibers will
puncture or penetrate into the substrate. Longer short segment
fibers may entangle with adjacent rooted tuftstrings and thus,
share bonding force with adjacent tuftstrings (see FIG. 3B).
However, there is a limit to the desired length of the short
segment fibers. At some length, determined by composition,
cross-section, shape, etc., the bond strength of the roots can
exceed the failure strength of the fiber in the dense portion of
the rooted tuftstring. Thus, there is no value in increasing the
length of the roots unless the purpose is to strengthen the
substrate material. Cost is also a consideration here. As short
segment fiber length is increased, the raw material cost increases
as well. An optimum length can be selected based on the material
chosen and testing that ensures adequate anchoring strength in a
desired cost range.
[0080] In a preferred position the beam is positioned between the
supply yarn and the mandrel as the supply yarn is wrapped around
the mandrel (as described in U.S. Pat. No. 5,472,762, incorporated
by reference above). In an alternative embodiment, however, the
beam can be secured to the wraps or flights of yarn such that the
wraps are positioned between the beam 119 and the mandrel. The
characteristics of the densely packed, bonded region remain the
same as described with reference to FIG. 2A.
[0081] The unique geometry of the pile sub-assembly is described
below, and is presented "normalized" by expressing dimensional
features as a ratio to the free yarn bundle diameter. The yarn
bundle diameter is a parameter that is related to the ability of
the yarn to cover a surface in an efficient manner in a fabricated
article. For repeatability in measuring, the yarn bundle diameter
is the untensioned average diameter of a one inch long straightened
section of a longer bundle segment remote from the cut ends to
avoid the ambiguity that flaring of the cut ends may cause when
making a measurement. The yarn bundle diameter can be repeatably
measured using a microscope with grid lines or an optical
comparator, such as a "Qualifier 30" made by Opticom. FIG. 6 shows
a view of the yarn on the Qualifier 30. A one inch piece of
straight yarn with no cut end flare (which may be straightened with
very low tension that does not appreciably compact the yarn) is
placed on top of a flat block 181 located in the light path of the
comparator. At a 20.times. magnification, the sample 182 is aligned
with a horizontal line 184 on the comparator screen that is passed
through the peaks and valleys along the edge of the sample to
define an average edge location. The line is moved to the opposite
average edge of the yarn at position 186 and the distance moved 188
is recorded as the average "diameter" of the one inch long sample.
This may be repeated with several samples of the supply yarn to
further average the "diameter". In the case where there are
different diameter bundles along the beam, the bundle diameter
would be the average diameter of all the, different bundle
diameters along a representative length where the pattern of
different diameters repeats. The bundle diameter of a yarn may be
about 0.114 inches, and is preferably between 0.020 inches and
0.150 inches.
[0082] As previously noted the present invention is applicable to
both singles and twisted/plied yarns. The singles yarn is not a
twisted or highly entangled bundle of fibers. There is a "leveling"
of the loosely entangled filaments of the singles yarn by the
ultrasonic horn in the bonding process which tends to average and
redistribute the yarn filaments. The relationship of the bundles to
each other along the support beam is defined by the pitch for
twisted yarn, which is the distance between bundles along the
support beam, by the width of the support beam, and by the bundle
diameter. Singles yarn has no distinguishable P/D ratio.
[0083] The bundle pitch/bundle diameter ratio (P/D ratio) describes
the distance between adjacent bundles of yarn (pitch) laid along a
length of support beam compared to the yarn bundle diameter. The
unique process of the invention allows the product to have a much
denser distribution of bundles along the beam than other elongated
pile articles taught in the art. When the yarn is wound onto the
support beam there are at least three methods of achieving a high
density of bundles on the beam: 1) apply enough tension to the yarn
bundle that the diameter necks down such that when the necked down
yarns are laid adjacently abutting each other along the beam, the
pitch is less than the free untensioned bundle diameter; 2) wind
multiple layers of yarn bundles on the beam; and 3) a combination
of the first two.
[0084] In contrast to the "U" shaped tuftstring of the prior art,
the P/D ratio for the rooted tuftstring will generally be two times
(2.times.) that of the "U" shaped tuftstring to achieve the same
pile density. Since the second shorter segment of the fiber bundle
is used to attach the rooted tuftstring to a support substrate, it
is not available as pile for the exposed surface as is the case
with the "U" shaped tuftstring. Doubling the pitch to achieve the
desired density provides a corresponding density of roots to ensure
a high anchoring strength for the rooted tuftstring.
[0085] The P/D ratio can be further appreciated referring to FIGS.
7 and 8. The bundles of yarn are bonded to the opposite side of the
beam 119 shown as simplified tufts, 205a, 206a, and 208a. The
simplified tufts are bonded to the beam at the densely packed
region 162. The simplified rooted ends 205b, 206b, and 208b are
shown extending past the beam. The pitch "P" of the bundles along
the beam 119 is best understood referring to FIG. 7 and looking at
the abutted center-to-center spacing or pitch 210 between the dense
bonded portions of adjacent bundles. It is preferable to measure
pitch here instead of at the end of the tuft since the tuft ends
are somewhat free to move about. The diameter of the bundle "D" is
represented by the distance across an untensioned bundle or
diameter 75. The pitch may have to be averaged along a one inch
length to get a representative number as some local variations are
to be expected.
[0086] FIG. 8 shows how the pitch is determined when there are
multiple layers of bundles along the beam 119 and the simplified
root end portions of the bundle bonds may overlap one another.
Bundle tufts, such as 205a, 206a, 214a, and 215a are shown above
beam 119 and the overlapped dense rooted end portions of the bundle
bonds for these bundles are shown below the beam 119, as 205b,
206b, 214b, and 215b, respectively. The pitch "P" is the distance
between adjacent dense portions 162 of bundles successively placed
along the beam at pitch 210. Once again, the number of bundle bonds
along a one inch section may need to be averaged to get a
representative number for "P". In the case where there are
different diameter bundles along the beam, perhaps causing the
pitch to vary considerably, the pitch would be an average
represented by the reciprocal of the number of bundles per a
representative length where the pattern of different diameters
repeats. The bundle pitch may be about 0.033 inches, and is
preferably-between about 0.015 and 0.150. The P/D ratio may be
about 0.30, and is preferably between about 0.1 and 7.5.
[0087] The width of the support beam is an important parameter in
the present invention for the following reasons: 1) it must have an
outer perimeter sufficient in size to enable the use of the rooted
tuftstring guide assembly (FIGS. 16 and 17); and 2) if it is too
wide, it may cause the spacing between adjacent pile sub-assemblies
to be excessive such that a dense array of yarn tufts in a
fabricated article cannot be achieved. A rectangular beam has
several advantages and is preferred, though other cross-sectional
shapes can also be useful. The vertical side to which the yarn
filaments are bonded has a larger surface than would for example,
the intersection of the yarn with the tangential surface of a round
or oval beam. The flat top and bottom surfaces are useful in
aligning the pile segments vertically. The flat top of the beam
pressed against a slightly larger flat of the guide assembly works
in unison with the slot used to pass through the long fiber
segments to prevent rotation of the rooted tuftstring as it is
processed with a backing substrate. The horizontal flat bottom side
of the beam provides a stable surface as opposed to curved surfaces
such as those of a round or oval beam. The beam width is preferably
0.010 to 0.70 inches.
[0088] There is a structural feature, which is important in certain
embodiments, that is related to the manner in which the bundle of
filaments, i.e. yarn, is bonded in the densely packed region 162 to
the beam 119. Continuous filaments within each of the yarn bundles,
secured to the beam and further anchored to the substrate ensures a
high probability of capture and high retention strength for each
individual fiber. However, the higher strength has been found to be
to the adhesive and not to the beam when the appropriate adhesives
are selected. In the present invention the rooted tuftstring, for
the reasons stated above, minimizes linting (e.g. loose fibers
released from the pile article due to breakage).
[0089] Although the invention has been described above as being
made on an automated device, an alternate embodiment of the
invention can be made by manual means or any other suitable means.
Referring now to FIGS. 9A and 9B, the supply yarn 20 can be wrapped
by hand around a thin rectangular mandrel 282, for example, having
support beams 119 taped or otherwise held in place along grooves
288 and 290. After the supply yarn 20 is in place, an ultrasonic
horn 292 can be passed along the yarn, wrapped around grooves 288
and 290, to bond the yarn to beams 119. The yarn can then be cut by
a cutter or slitter 294 at a predetermined location, proximal to
the beam 119, on either side of the mandrel. For greater efficiency
and speed, a slitter may be located above the beam in groove 288 as
shown in FIG. 9A and below the beam 119 in groove 290 (see FIG. 9B)
or vice versa. In this manner, two elongated pile sub-assemblies
are easily produced. The first elongated pile-sub-assembly has
short bundle segments relative to groove 288 at the end above the
beam 119 cut by the slitter 294. The long bundle segments of the
rooted tuftstring would be the portion extending from the 119 beam
at groove 288 to the slitter 293 located below the beam 119 at
groove 290 in FIG. 9B. The remaining slit yarn separated from the
first elongated pile sub-assembly forms the second elongated pile
sub assembly. If only a single rooted tuftstring assembly is
desired, the second beam and slitter are omitted along one ridge.
The mandrel can have a length 296 that is as wide as the carpet or
article in which the rooted tuftstring is to be used.
[0090] To assist in wrapping the yarn, the mandrel may be mounted
in a rotatable chuck and the yarn traversed along the rotating
mandrel. A lathe with a traversing crosshead may be usefully
employed to so place the yarn on the mandrel. In the most general
sense, the product can also be made by laying one precut yarn
bundle at a time over the beam and groove of the mandrel and
bonding the bundle so that the wrapping step is not required.
[0091] One method for making an elongated pile sub-assembly of the
present invention comprises: contacting an elongated support beam
with a plurality of bundles of filaments at a location along the
perimeter of the beam; bonding the filaments both, to each other
(to form a dense portion in the bundle where the filaments are
bonded together) and to the beam at a location along the beam. In
the present invention, one method of bonding the supply yarn to the
beam includes an ultrasonic driver such as a Dukane Corp. model
40A351 power supply capable of 350 watts at 40 KHz, connected to a
Dukane Corp. 41C28 transducer. A Dukane booster may also be used.
Bonding means other than ultrasonic bonding may also be employed to
form the compacted portion of the bundle by securing the filaments
to each other and to the beam. Such means may be solvent bonding or
thermal bonding with, for instance, a hot bar; or some combination
of solvent, conductive, and ultrasonic bonding. Or, an adhesive may
be introduced to the location where the bundle is secured to the
beam to form an adhesive bond between the bundle and the beam.
[0092] The elongated pile sub-assembly of the invention may be used
to make a fabricated article such as a pile surface structure,
including flooring articles, paint brush rollers, etc. or a brush
surface structure, including toothbrushes, a buffing wheel, etc. A
brush may be made in a variety of configurations, with or without a
handle. The elongated pile sub-assembly of the invention may be
used to form a pile brush face. The pile brush face is the portion
of the brush that may be used, for example, to apply or remove a
liquid material, or to alter a surface by the application or
removal of a liquid material. The pile brush face on a brush may be
generally planar in shape, or it may take on other shapes such as a
generally cylindrical shape.
[0093] A roller brush, used for an activity such as the application
of paint, is a typical example of a brush having a generally
cylindrical pile brush face. The case of a roller brush may be
illustrated, for example, as in FIGS. 10 and 11, which show a
roller brush 310 having a pile covering 312 as a brush face mounted
on a hollow core 314. The hollow core 314 can have any suitable
shape, such as cylindrical or oval, depending upon the application.
The pile covering 312 is made of at least one elongated pile
sub-assembly 125 (FIG. 2A) having a support beam 119. The elongated
pile sub-assembly 125 has at least one bundle of yarn secured to
the support beam 119 in which a longer bundle segment 126 defines a
pile-forming tuft as shown in FIG. 2A. The core of a roller brush
is typically rotatable about a handle member, not shown.
[0094] With continuing reference to FIGS. 10 and 11, the pile
covering 312 is formed by securing one or more pile sub-assemblies
to the outer surface of the core 314. In a preferred embodiment,
one or more pile sub-assemblies is wrapped spirally and
continuously around the outer surface of the core 314.
Alternatively, however, an elongated pile sub-assembly may be
mounted on the core 314 in an alignment in which the elongated pile
sub-assembly is longitudinal, i.e. parallel to the centerline axis
of the core, or in an alignment in which it describes a circle
about the longitudinal axis along the circumference of the core, or
in other variations on any of such alignments as described.
Elongated pile sub-assemblies may be secured to the core in
parallel alignment to each other.
[0095] The elongated pile sub-assembly 125 (see FIG. 4) is secured
to the core 314 by any suitable bonding means, including an
adhesive binder applied to the outer surface of the core 314
immediately prior to a step of wrapping or otherwise affixing the
pile sub-assembly to the core. Chemical or thermal binding
processes may also be employed as well, however, in addition to
other mechanical binders, such as anchors disposed at opposite ends
of the core 314, or a hook and loop locking system. When a thermal
binding process is used, it is preferred that the core and/or the
elongated pile sub-assembly, or both, be prepared from a polymeric
material. A portion of the core and/or a portion of the elongated
pile sub-assembly, or a portion of both, may then be softened by
inducing a temperature therein above the melting or glass
transition temperature of the polymeric material. At a temperature
above melting or glass transition, the softened polymeric material
will flow, creating a zone of polymer flow. The increased
temperature causing polymer flow may be attained by radiant or
conductive heating means, but preferably by ultrasonic energy. As
the polymeric materials from which the core is made flow and
contact the elongated pile sub-assembly, or, as the polymeric
materials, from which the elongated pile sub-assembly is made, flow
and contact the core, or as both results occur, the flowing
polymeric materials become welded and secured at the point of
contact after they cool and resume solid state. As an alternative
to increased temperature, the zone of polymer flow may be created
by the application of a suitable solvent to any of the components
that have been fabricated from a polymeric material.
[0096] The core 314 may be prepared from a polymeric material, as
aforesaid, or can be prepared from paper and resin which have
adhesive applied thereto. The core 314 can also include spiral
windings of paper impregnated with resin to which adhesive and
fabrics are applied to form a continuous profile.
[0097] In one embodiment, a pile covered fabric is prepared, at
least in part, from a material having a surface that has pores,
perforations or apertures, or the like; such as a screen, mesh or
mesh-like material. In such an embodiment, the shorter bundle
segment 127 of the elongated pile sub-assembly may be secured to
the fabric mesh, and this may be accomplished by arranging to have
the filament segments in the shorter bundle segments penetrate the
mesh-like material. The pile covered fabric is then attached to the
core. In other embodiments, however, the shorter bundle segment of
the elongated pile sub-assembly may be secured to the surface of
the core; or the elongated pile sub-assembly may be secured to the
core by a bond between the core and the support beam, or a bond
between the core and portions, or all, of both the shorter bundle
segment and the support beam. In these embodiments, the shorter
filament segments may become the point of contact for the
application of adhesive between the substrate and the elongated
pile sub-assembly, forming an adhesive bond between the substrate
and the shorter filament segments, or the shorter filament segments
may be the location of, and be contacted with, a zone of polymer
flow. The shorter filament segments act as roots in these
embodiments, ensuring a solid bond between the elongated pile
sub-assembly and the substrate.
[0098] Referring to FIG. 12, another embodiment of the present
invention is shown in which elongated pile sub-assemblies 424, 426,
428, 430 are secured to a backing tape 440 by means of hot melt
adhesives at the interface of the tape and the shorter bundle
segment and/or the support beam of each elongated pile
sub-assembly. When the elongated pile assembly is spirally wrapped
around a core 442 (FIG. 14), as described in U.S. Pat. No.
5,547,732, the tape 440 has abutting or adjacent wraps on which the
elongated pile sub-assemblies from opposite sides of the tape are
adjacent to each other, i.e. such that, after one flight or wrap of
the tape, elongated pile sub-assembly 424 is adjacent to elongated
pile sub-assembly 430. (See U.S. Pat. No. 5,547,732). FIG. 13 shows
the bonding of the short segment fibers to the support fabric
without the act of adhesives, such as when ultrasonic energy is
used.
[0099] Other uses for an elongated pile sub-assembly, according to
the present invention, are to make a pile surface structure. A
pile/brush surface structure is useful for further fabrication into
a variety of articles such as a wall or floor covering, or an
airplane or automotive component for a motor vehicle such as a door
panel, a headliner, a floor or trunk mat, or seat upholstery. FIG.
15 shows a method to make a pile surface structure such as carpet
using the pile sub-assembly of the invention. A drum 78 is set up
for rotation with a backing material 80 attached, for instance, by
clamping the ends 82 and 84 of the backing in a slot 86 in the
drum. The surface 87 of the backing facing outward would be coated
with an adhesive coating, such as a thermoplastic adhesive. An
assembly 88 is set to traverse parallel to the rotational axis of
the drum and carry an elongated pile sub-assembly guide 90 and a
hot glue applicator nozzle 92 to position and meter a thermoplastic
or thermoset adhesive just before or coincident with contact with
the elongated pile sub-assembly and on its center line. Other ways
of heating may include a hot air jet, radiant heater, or flame. The
elongated pile sub-assembly 45 could be supplied from a reel 94 or
directly from a mandrel.
[0100] With continued reference to FIG. 15, as drum 80 is rotated
clockwise, the elongated pile sub-assembly is pulled through guide
90, and pressed against the applied adhesive on the fabric surface
87 of backing 80. The elongated pile sub-assembly contacts the hot
adhesive and is bonded to the backing. The assembly 88 is
synchronized to traverse along the drum surface and lays down a
spiral array of the elongated pile sub-assembly to the backing
surface, with adjacent runs of the spiral closely spaced such that
the just-applied elongated pile sub-assembly lies close to the
previously-applied elongated pile sub-assembly in the spiral array
to define a pile surface structure. After the elongated pile
sub-assembly has been traversed the axial length of the drum
surface, the winding is stopped, and the assembly of the elongated
pile sub-assembly and backing is cut along the drum axis, such as
at line 96 where the two backing ends come together at slot 86. In
the embodiment shown, only the elongated pile sub-assembly need be
cut at 96 and the backing ends released to remove the pile
structure assembly. The pile structure assembly can then be removed
from the drum and laid flat to form a pile surface structure or
carpet.
[0101] The carpet product made by this method has the feature that
the adjacent rows of elongated pile sub-assemblies come from
different elongated portions of the same elongated pile
sub-assembly which eliminates yarn lot variations within the
carpet. For instance, a carpet having about 3.3 oz/ft.sup.2 of yarn
can be produced by first making an elongated pile sub-assembly from
2350 denier, two strands, ply twisted yarn bonded along the beam at
30 wraps/inch and a 5/8 inch tuft length, and then mounting the
pile sub-assembly on the backing at a pitch of 5 pile
sub-assemblies/inch.
[0102] In variations of the method, and the product resulting from
the method, shown above, the substrate backing may be selected from
woven or spun-bonded materials. The selection of fabrics such as
Sontara.RTM. by E. I. DuPont de Nemours, Reemay.RTM. by Reemay
Incorporated and Cerex.RTM. from Cerex Advanced Fabrics are
particularly useful since they are made of polymeric material,
offered in various weights and density, and can be used with the
various methods for attaching rooted tuftstrings to them. Although
natural fiber fabrics can be used they are limited to the use of
adhesives to bond the rooted tuftstrings to them. An elongated pile
sub-assembly may be secured to a backing substrate to make a pile
surface structure by selecting one of an adhesive, thermal bonding
or solvent bonding. An elongated pile sub-assembly may be secured
to a backing substrate by use of the support beam and/or the
shorter bundle segment, on or beneath the surface of the backing
substrate, in the same manner as employed for brush construction.
Although the use of adhesive, thermal or solvent bonding means may
be preferred, an elongated pile sub-assembly may alternatively be
secured to a backing substrate by conventional stitching and/or a
hook and loop attachment system.
[0103] Alternatively, the rooted tuftstrings can be attached to
sheets of polymer with relatively "solid" surfaces such as sheets
made of epoxy resins, thermosets, thermoplastics, wood, and even
metal. (Some of these methods of attaching require the use of
adhesives.) As described above with respect to a brush, an
alternative to wrapping the elongated pile sub-assemblies spirally,
as shown in FIG. 15, is to make a pile surface structure by
creating an array in which one or more elongated pile
sub-assemblies are, for example, in parallel alignment to each
other and brought into contact with a bonding surface of a backing
substrate.
[0104] Another method of securing more than one elongated pile
sub-assembly to a backing substrate is shown by the guide
assemblies of FIGS. 16 and 17. Unlike the rotating drum process
described above, these guide assemblies are capable of continuous
operation and do not have to be stopped to remove the "carpet" of
elongated pile articles. FIG. 16 shows a schematic view of a guide
for the elongated pile sub-assembly 125 to create a pile fabric or
article. This flat guide assembly 90 is better suited for
relatively stiff substrates that would resist bending or would
otherwise take on a set from the curved guide 91 of FIG. 17.
[0105] In FIG. 16, the long flat bottom surface is positioned with
a suitable gap between and parallel to (not shown) the substrate
and the guide assembly 90. The gap 310 is determined by one or more
variables which include the length of the short fiber segments 127,
the vertical dimension 315 of the beam, the depth of the beam guide
groove 320 and the depth of the adhesive. The beam dimension 315
must not be able to pass through the spacing of 325. The gap 325
loosely confines the portion of the long bundle segment proximal to
the beam 119 together with gap 328 which loosely confines the beam
to correctly position the short and long fibers normal to the
substrate. Generally speaking the spacing 325 is greater than 20%
of the beam width 322 and more preferably between 20% and 50% of
the beam width. A typical set-up would position the guide 90 with
an elongated pile sub-assembly 125 threaded into the guide 90 over
the flat substrate with a minimal gap between the bottom surface of
the beam and the substrate to substantially splay the short segment
filaments 127 without causing binding of the elongated pile
sub-assembly 125 as it passes through the slot 97 of the guide
assembly 90.
[0106] The rooted tuftstring pile articles are continuously
supplied from one or more rooted tuftstring machines or from an
inventory on spools. The elongated pile sub-assemblies are directed
by rolls and guide pins (not shown) into the grooves of the guide
with the short bundled end extending outward therefrom. The guide
mechanism guides a plurality of individual short bundle segments of
elongated pile sub-assemblies into contact with the preferably
continuously fed backing substrate. An adhesive material such as a
thermoset or thermoplastic adhesive is applied to the surface of
the substrate just prior to passing under the guide assembly.
Ideally, the linear rate of the process and the heat capacity of
the adhesive is adequate to achieve good wetting and encapsulation
of the short fiber segments prior to bonding with the substrate.
The adhesive is cooled as it passes under the guide assembly such
that at the exit of the guide, the rooted tuftstrings are unable to
reposition themselves.
[0107] Another process embodiment of the present invention for the
flat guide of FIG. 16 uses a thermoplastic polymer melt delivery
system and die assembly to cast or to form the substrate on the
exposed surface of the guide assembly 90 having exposed portions of
elongated pile sub-assemblies extending therefrom. In this case,
the guide is inverted such that the short fiber bundles extend
vertically upward from the guide. A polymer melt delivery system
drops a curtain of polymer melt onto the top guide surface. A band
or strip of material such as Kapton.TM. or Teflon.TM. may be used
as a barrier to protect otherwise exposed metal surfaces from the
polymer melt when the polymer melt has a tendency to adhere to the
metal. The guide surface is sufficiently cool and causes a rapid
freezing of the polymer melt with the short segment fibers
encapsulated therein. The elongated pile articles assist in
transporting the melt from the plate and cooling of the
thermoplastic polymer. Since the elongated pile articles are
sufficiently strong and not excessively heated, the sheet of
polymer will be adequately supported by the elongated pile articles
after it leaves the guide and continues to cool.
[0108] Another process embodiment of the present invention is shown
schematically in FIG. 17. The short segment fibers 127 of the
elongated pile sub-assembly 125 face toward the bonding element
(e.g. adhesive applicators 95) as the elongated pile sub-assembly
are feed through the guide 91. The short bundle segments of the
elongated pile sub-assembly preferably wipe the adhesive from the
applicator end and the elongated pile sub-assembly continuously
wipes the guide surface to avoid a large build up of adhesive in
the guide as the elongated pile sub-assembly is feed through the
guide. The fabric backing 99 is fed in concert with the tuftstring
for bonding by one or more of the adhesive applicators 95 forming a
pile covered fabric 199. Although two applicators are shown in this
embodiment, one may be sufficient. If one adhesive applicator 95 is
used the adhesive can be applied to the short bundle segments 127
just prior to their contact with the substrate 99 or alternatively,
directly to the fabric backing or substrate 99. The number of
applicators used may also be increased to more than two in this
embodiment if required.
[0109] This process embodiment is well suited for substrates that
are flexible enough to conform to the curvature of a roll 91. The
low thermal conductivity of most substrates allow a hot melt
adhesive to be applied directly to the substrate with good heat
retention and high flow properties upon contact with the short
bundle segments of the rooted elongated pile article. For some
substrates, some heating of the roll 93 may be required to maintain
fluidity of the adhesive until time for the desired bonding. This
heating of the roll 93 may be needed particularly when the
substrates are extremely thin.
[0110] As with the guide assembly of FIG. 16, the guide device of
FIG. 17 must be set up properly for optimum performance. The
curvature of the guide assembly 91 is designed to be concentric
over the arc length with the roll surface. Again the distance
between the roll 93 rotating in the direction of arrow 98 and the
guide 91 is established to ensure the short segment fibers splay
and/or penetrate properly when pressed into the substrate as shown
in FIGS. 2A.about.4.
[0111] In both FIGS. 16 and 17, the guide assembly can be mounted
onto a mechanism which permits adjustment of the guide vertically
and if desired, horizontally. This is advantageous since the guide
can be retracted for cleaning, thread-up or other
preparatory/maintenance activities. Small incremental adjustments
in positioning can be accomplished while operating the process.
[0112] FIGS. 18A and 18B show ultrasonic bonding of the rooted
tuftstring 125 to the substrate 115 in the present invention. The
ultrasonic horns 340, 345 vibrates in the direction shown by arrows
342, 343, respectively, with anvils 350,355, respectively providing
a rigid support for the ultrasonic horns. A force 346, 347 presses
the substrate 115 and the short segment fibers into contact with
each other while vibrational energy is transmitted from the
energized horn. The vibrational energy generates frictional heating
at the interface causing surface melting of at least one of the
short segment fibers 129, the beam 119, and the substrate 115,
creating a polymer flow zone that will bond the elongated pile
sub-assembly to the substrate. FIGS. 18A and 18B show the anvils
350, 355 and the horns 340, 345, respectively, functioning as
elongated pile sub-assembly guides, respectively.
[0113] It is, therefore, apparent that there has been provided in
accordance with the present invention, an elongated pile
sub-assembly having "roots", guide device and products made from
the elongated pile sub-assemblies, that fully satisfies the aims
and advantages hereinbefore set forth. While this invention has
been described in conjunction with a specific embodiment thereof,
it is evident that alternatives, modifications, and variations will
be apparent to those skilled in the art. Accordingly, it is
intended to embrace all such alternatives, modifications and
variations that fall within the spirit and broad scope of the
appended claims.
* * * * *