U.S. patent number 3,890,681 [Application Number 05/487,668] was granted by the patent office on 1975-06-24 for apparatus for needling textiles.
This patent grant is currently assigned to Huyck Corporation. Invention is credited to Eugene Zoltan Fekete, Raymond J. Grady.
United States Patent |
3,890,681 |
Fekete , et al. |
June 24, 1975 |
**Please see images for:
( Certificate of Correction ) ** |
Apparatus for needling textiles
Abstract
This invention relates to apparatus for performing so-called
"needling" operations on textile goods, which apparatus is
characterized by the fact that it comprises a needle support member
having a multiplicity of felting needles affixed thereto, the long
axes of which are oriented substantially normal to the surface of
said member, and an associated backing member to support the
textile material against the forces experienced during the needling
operation, which backing member has a surface comprising
pressure-tolerant, laterally displaceable, elongated members which
are affixed at one end to the surface of the backing member and
have their long axes oriented substantially normal to the surface
of said backing member; said needle support member and said backing
member each being so structured as to travel repeatedly along a
closed travel path each aggregating 360.degree. of angular change
and being so positioned with respect to each other that at least at
one point along their paths of travel, portions of said needles
reside among said elongated members.
Inventors: |
Fekete; Eugene Zoltan (East
Greenbush, NY), Grady; Raymond J. (Colonie, NY) |
Assignee: |
Huyck Corporation (Wake Forest,
NC)
|
Family
ID: |
23936671 |
Appl.
No.: |
05/487,668 |
Filed: |
July 11, 1974 |
Current U.S.
Class: |
28/107 |
Current CPC
Class: |
D04H
18/02 (20130101) |
Current International
Class: |
D04H
18/00 (20060101); D04h 018/00 () |
Field of
Search: |
;28/4R,72.2R |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Rimrodt; Louis K.
Attorney, Agent or Firm: Hargest; Robert F. Wadler; Sanford
S.
Claims
We claim:
1. An apparatus for needling textiles comprising
a needle support member which is capable of traveling along a
closed travel path and has a multiplicity of felting needles
affixed thereto, the long axes of which are oriented substantially
normal to the surface of said member,
and a backing member which is capable of traveling along a closed
travel path and has a surface comprising pressure-tolerant,
laterally displaceable, elongated fabric support members which are
affixed at one end to the surface of said backing member and have
their long axes oriented substantially normal to the surface of
said backing member;
said closed travel paths each aggregating 360.degree. of angular
change and being so positioned with respect to each other that at
least at one point along said paths, a portion at least of said
needles will reside among said elongated members.
2. The apparatus described in claim 1 wherein said surface of said
backing member comprises card wire.
3. The apparatus described in claim 1 in which at least one of said
members is a cylinder.
4. The apparatus described in claim 2 in which at least one of said
members is a cylinder.
5. The apparatus described in claim 1 in which said needle member
and said backing member are cylinders.
6. The apparatus described in claim 5 in which said surface of said
backing member comprises card wire.
7. The apparatus described in claim 5 wherein the diameter of said
needle-bearing cylinder is at least 122 centimeters and the
diameter of said backing cylinder is at least 30 centimeters.
8. The apparatus described in claim 5 wherein the diameter of said
needle-bearing cylinder is equal to the diameter of said backing
cylinder.
9. The apparatus described in claim 6 wherein the diameter of said
needle-bearing cylinder is equal to the diameter of said backing
cylinder.
10. A method of needling textiles comprising the steps of moving a
fabric through the point of closure between a needle support member
having needles affixed thereto the long axes of which are oriented
substantially normal to the surface of said support member, and a
backing member having pressure tolerant, laterally displaceable
elongated fabric support members affixed at one end to the surface
thereof, the long axes of which are oriented substantially normal
to the surface of said backing member, moving said members along
closed travel paths each aggregating 360.degree. of angular change,
positioning said members with respect to each other so that at
least at one point along said paths, a portion at least of said
needles will reside among said members.
11. A method according to claim 10 wherein at least one of said
members is a cylinder rotating 360.degree. about it's longitudinal
axis.
12. An apparatus for needling textiles comprising
a needle support member which is capable of traveling along a
closed travel path and has a multiplicity of felting needles
affixed thereto, the long axes of which are oriented substantially
normal to the surface of said member,
and a backing member which is capable of traveling along a closed
travel path and has a surface comprising pressure-tolerant,
laterally displaced, elongated fabric support members which are
affixed at one end to the surface of said backing member and having
their long axes oriented substantially normal to the surface of
said backing member;
said closed travel paths each aggregating 360.degree. of angular
change and being so positioned with respect to each other that at
least at one point along said paths, a portion at least of said
needles will reside among said elongated members, said support
member being movable relative to said backing member to control the
distance between said needle and backing members and thereby
control the depth at which said needles reside among said elongated
members.
13. The apparatus described in claim 12 in which at least one of
said members is a cylinder.
14. The apparatus described in claim 13 in which said needle member
and said backing member are cylinders.
Description
BACKGROUND OF THE INVENTION
It is well known in the textile arts that it is possible to make a
textile product by subjecting a batt of fibers to the repeated
plunging action of a multiplicity of so-called "felting" needles,
by which, in this context, is meant known per se, long, thin,
rod-like structures, usually round or angular in cross-section,
having one or more barbs in them, the preponderance of which face
toward the pointed end. In this connection, reference is made to
the following U.S. Patents: Foster, U.S. Pat. No. 2,322,573;
Kopriva et al., U.S. Pat. No. 2,326,038; Foster, U.S. Pat. No.
2,327,416; Foster U.S. Pat. No. 2,349,086; Foster, U.S. Pat. No.
2,391,560; Brown, U.S. Pat. No. 2,678,484; Lauterbach, U.S. Pat.
No. 2,857,650; Weickert, U.S. Pat. No. 2,882,585; Lauterbach, U.S.
Pat. No. 2,958,113; Foster, U.S. Pat. No. 3,224,067; Zocher, U.S.
Pat. No. 3,464,097; Foster U.S. Pat. No. 3,479,708; Zocher, U.S.
Pat. No. 3,566,663; Foster, U.S. Pat. No. 3,727,276; and McKew et
al., U.S. Pat. No. 3,230,599. The batt of fibers may be supported
on a backing scrim, which typically may be an open-weave mesh
fabric made in the traditional manner of textile manufacturing.
Such a combination, with the fiber batt facing the needle board of
the needling machine, is passed beneath the needle board, to which
are affixed a multiplicity of needles. In the most widely used
types of such machines, the needle board reciprocates upward and
downward by means of driven connecting rods, thereby producing the
plunging action which, because of the barbed configuration of the
needles, causes interlocking entanglement of the fibers with each
other and with the backing scrim, thereby giving the textile
product structural and mechanical integrity and an acceptable
degree of fiber retention. In this connection, reference is made to
the following United States Patents which disclose such machines:
Stone, U.S. Pat. No. 2,177,604; Walsh, et al., U.S. Pat. No. Re.
21,890; Marshall, U.S. Pat. No. 2,959,509; Chase, U.S. Pat. No.
1,742,133; and Chase U.S. Pat. No. 1,745,739.
Textile products made in accordance with these needling techniques
have been found particularly useful in the field of papermakers
felts where large numbers of fibers must be incorporated into the
felt in order to provide the degree of loft, resiliency, and
structural integrity that is required to render them useful in the
environment of the papermaking machine. However, the production of
needled textile products made by the previously known techniques
has been relatively slow and, in addition, the mechanical problems
involved in the construction and operation of the associated
machinery have been substantial, primarily because of the
reciprocal motion and the great weight and inertia attendant to
making the apparatus sufficiently strong and rigid to withstand the
high forces experienced in the needling operation.
The basis for the premise that reciprocating motion is necessary is
that the needles themselves necessarily are very thin, although
they must possess sufficient mechanical strength to tolerate the
stresses and strains to which they are exposed by virtue of the
existence of the barbs and the pressures imparted to the needle
shaft during impingement of the needle point and barbs on the
fibers and other portions of the textile product being made. In
view of this, and the fact that as the textile product is produced
it becomes progressively more dense, until the advent of the
present invention we believed that it was necessary to cause the
needles to enter and be removed from the textile fabric
substantially along a linear path; that is, one not involving any
significant amount of laterial pressure on the needles, or of
angular displacement and flexing of them, between the time the
needle point begins to enter the fabric and the time that it leaves
the fabric, since the effect would be to cause the constituent
material of the needles to fatique through work hardening resulting
from such flexing, and ultimately break. Flexing and the angular
displacement of the needles would additionally produce undesired
tearing and hole-enlarging effects on the associated fabric.
This problem is intensified by the fact that, as noted above, the
thrust pressures that must be exerted by the needle in order to
provide the desired effects of the needling operation are
substantially initially and become progressively greater as the
textile product densifies, and this makes it necessary for the
textile product to be backed against displacement to ensure that
the needles will penetrate the textile product to a predetermined
depth. Traditionally, this was achieved by means of a backing
plate; that is, a sheet of material, such as heavy gauge steel,
having perforations therein corresponding to the position, size,
and distribution pattern of the needles on the needle board,
whereby the barbs of the needles could be caused to plunge
completely through the textile product being fabricated and through
the holes in the backing plate. The very nature of such a backing
plate meant that the needles must enter it in exactly the same
places and configuration each time in order to avoid needle
breakage from impingement on the unperforated portions of the
backing plate, and it also meant that the potential needle density
was limited inherently because of the necessity of preserving
sufficient "land" area between the perforations in the backing
plate to give the plate enough strength to withstand the forces of
needling.
Some attempt has been made to replace such backing plates with
other structures, such as belts having "knee-action" plastic
filaments projecting therefrom; (in this connection, reference is
made to Hollowell, U.S. Pat. No. 2,974,393), but in the textile
art, such structures have not to date found wide-spread application
primarily because, as the Hollowell reference illustrates, such
filament belts were associated with reciprocating needle boards and
were merely substitutions for the backing plate. Although they may
have permitted greater needle densities than could be achieved with
a backing plate, they are inherently suited only to the needling of
relatively thin fiber batts because of the limited ability of the
"knee-action" filaments to support the fabric against high needling
pressures, and they still are substantially restricted to the low
production speeds of traditional needle looms because of having
reciprocating needle boards, presumably because of all the problems
of subjecting the needles to lateral pressures and flexing still
being present.
There have been attempts made to process sheet-like goods through
the nip formed by associated roll devices wherein protrusions from
at least one of the rolls perform work on the material being
processed. In this connection, reference is made to the following
patents: Harmon et al., U.S. Pat. No. 3,012,290; Harrigan, U.S.
Pat. No. 232,962; Gresham U.S. Pat. No. 2,920,373; Krolik, Jr.,
U.S. Pat. No. 3,137,611; Harwood, U.S. Pat. No. 3,038,215; Mueller
U.S. Pat. No. 2,847,086; Oace, U.S. Pat. No. 3,014,263; and British
Patent Specification No. 20,645. There have also been similar
machines which utilize belt-like structures other than opposing
rolls, for substantially the same purposes; (in this connection
reference is made to U.S. Pat. Nos. 3,025,585, Griswold; and U.S.
Pat. No. 2,762,433, Russell). However, none of the aforesaid known
references of either type were dealing with needles of the type
contemplated by the present invention. Rather, these references
deal with devices which were for the purpose of punching
perforations in sheet-like material, or embossing it, or performing
other such tasks, with penetrating structures that were not long
and thin and therefore did not have the kind of mechanical stress
problems which are inherent to the needles used in needling as it
is known in the textile arts.
Occasionally, attempts have been made to modify textile process
machinery to render it more simple structurally and faster than the
known per se reciprocating needle looms. Such attempts are
illustrated by Kalwaites, U.S. Pat. No. 3,081,501 and Hollowell,
U.S. Pat. No. 2,974,393; but these references also still resort to
reciprocating needle board motion as the means for propelling
needles into the textile material. Other prior art devices which
are more nearly like roll devices so made for the purpose of
speeding up the needling process have either not been concerned
with the long, thin, and relatively delicate needles contemplated
by the present invention, or have tolerated the generation of
objectionable relatively wide apertures in materials that are not
of a dense nature (in this connection, reference is made to
Kalwaites, U.S. Pat. Nos. 3,325,868 and 3,255,496).
It is believed that needling machines having opposing rolls, one
with the needles mounted thereon and the other with a backing
surface such as the perforated plate similar to the type previously
used as backing plates in reciprocating needle looms, have not been
found to be satisfactory because of the practical mechanical
problems which would be encountered in such devices. First, there
would be the very difficult problem of perfect "registration", or
causing each needle to align with a hole exactly in every pass;
otherwise, needle breakage would be experienced. Next, if one
visualizes the necessity for the needle shafts to pivot angularly
about a fictitious point approximately halfway along the axis of
each hole as each needle first intercepts, then penetrates, and
lastly withdraws from its associated hole as the two pass through
arcuate paths through the nip region of the rolls, it will be
appreciated that the holes will have to be increasingly larger as
the roll diameters decrease, as the depth of needle penetration
increases, and as the thickness of the backing plate increases, and
this enlargement reduces the possibility for effective backing and
therefore increased needle density.
One reference (British Patent Specification No. 450,775) discloses
an apparatus which is an attempt to increase the speed of needling
by use of a series of needle boards traveling on an endless belt
and opposed by an inclined plane backing plate. The drawbacks of
this structure in terms of the lateral stress moments which it
places on the needles are apparent from an examination of the
apparatus as disclosed since, of course, the entry-withdrawal
sequence of the needles effected by the cooperation between the
inclined plane bed plate and the endless belt of needles is clearly
of such a nature as to cause the relative motion of the needles,
due to the raising of the textile product being needled up the
incline of the backing plate to the crown and then down it, to be
as if the needles were being pivoted through an arc about a
fictitious point which moves along their respective shafts. This,
apparently, makes such a machine impractical in the long run, as
evidenced by the fact that the apparatus has not found wide-spread
use in the industry. Furthermore, because of the ribbed
configuration of the backing plate substitute which apparently is
necessitated by the substantially linear progress of the needles in
this arrangement, it is not possible to have a very high needle
density which, of course, would help improve the efficiency of
needling.
Recognizing the drawbacks of all of the foregoing structures and
visualizing the advantages which would result if it were possible
to produce a pure roller-type structure, various persons skilled in
the art have made attempts from time to time to produce structures
that would at once perform needling of the high quality level
desired, while, at the same time, simplifying the machinery,
speeding up the process time, and avoiding the deleterious effects
on the needles themselves. In this connection, reference is made to
Hall et al., U.S. Pat. No. 3,208,125; and Williams et al., U.S.
Pat. No. 3,372,447. It will be noticed that all of these
references, however, require the use of internal camming structures
which either cause the associated needles to plunge in and out of
the roll face, or cause them to be made to cant mechanically, so as
to avoid the angular displacement problems noted above, as well as
the lateral bending moments imparted by the angular displacement
that takes place as the needles first enter and then are withdrawn
from the textile material being processed through the course of the
material passing through an arc of some dimension. Clearly, such
devices are very intricate and expensive, and are subject to
extreme and rapid wear, and so are not suited to use on high-speed
textile processing machinery.
Accordingly, it is an object of the present invention to provide a
new and improved apparatus and method for needling textile
materials with a greater number of penetrations per unit time
occuring without intolerable adverse effects on the needles or the
quality of the textile products so produced.
SUMMARY OF THE INVENTION
The objects of this invention may be achieved through any of its
embodiments in which there is utilized an apparatus for needling
textile goods comprising a needle support member having a
multiplicity of felting needles affixed thereto, the long axes of
which are oriented substantially normal to the surface of said
member, and an associated backing member to support the textile
material against the forces experienced during the needling
operation, which backing member has a surface comprising
pressure-tolerant, laterally displaceable, elongated members which
are affixed at one end to the surface of the backing member and
have their long axes oriented substantially normal to the surface
of said backing member; said needle support member and said backing
member each being so structured as to travel repeatedly through a
closed path of travel, and being so positioned with respect to each
other that at least at one point along their paths of travel said
needles reside among said elongated members.
DESCRIPTION OF DRAWINGS
FIG. 1 is a schematic drawing of one embodiment of the present
invention,
FIG. 2 is a cross-sectional drawing of backing material useful in
the practice of a further embodiment of the present invention.
FIG. 3 is a graphic representation of the embodiment of the present
invention depicted in FIG. 2 in use, and
FIG. 3a is a graphic representation of prior art apparatus.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring first to FIG. 1, there is illustrated a textile needling
machine 10 embodying the present invention, comprising a needle
support member 12 and an associated backing member 14. In this
particular embodiment, members 12 and 14 are depicted as rolls.
There is also illustrated a carrier roll 16 the purposes of which
are hereinafter described, although it will be clear that the use
of such a carrier roll with the present invention is optional. The
needle roll 12 comprises a roll body 18 of typical, known per se,
cylindrical form, to the surface of which is affixed, by known
techniques, such as gluing with adhesives, or mechanical
affixation, or welding, brazing, or the like, a multiplicity of
needles 20 of any of a wide variety of constructions and designs
which are known per se in the textile needling art. The associated
backing roll 14 comprises a roll body 22, to the surface of which
is affixed a multiplicity of elongated members 32 which have one of
their ends affixed to the backing roll body 22 and which are
characterized by being able substantially to retain their shape and
orientation under the forces delivered to them in their axial
direction (which characteristic is referred to herein as
"pressure-tolerant"), and yet are laterally displaceable; that is
susceptible to being moved from side to side around their fixed
ends acting as pivots. So called "card wire", well known in the
textile arts, is suitable for this use and possesses the foregoing
structural features. It comprises a card wire structure 29 of the
type illustrated in FIG. 2 comprising a sheet-like member 30 made
from textile goods, rubber, heavy plastic material, and the like,
from one surface of which project a multiplicity of cut wire
members 32 made from material such as bronze, steel, plastics,
synthetic materials, or the like, typically of a diameter of about
0.08 cm, and in length about 2.5 cm, the outermost ends of which
occupy a plane substantially parallel to the surface of the
supporting back member 30. The elongated members 32 of such a
structure are free to bend or pivot about points 34; that is, the
point at which each emerges from the upper plane of the backing
member 30, so that as portions of a needle 20 penetrate among the
members 32, such portions may move relative to the elongated
members 32, and the elongated members are free to deflect sidewards
to give such penetrating portions of the needle freedom to so pass
unobstructed. At the same time, the cut wire members 32 are
sufficiently rigid to support the pressures imparted by such things
as a fabric being processed without substantially losing their
shape or orientation, not only against the normal tensions and
operationsl forces herein contemplated, but also against the forces
applied as the fabric moves through the point of closure between
the needle roll 12 and the backing roll 14 wherein the needles 20
on the needle roll 12 are caused to be plunged through and
extracted from the fabric being processed. In accordance with the
teachings of the present invention, that portion of the needle
which is in contact with the felt, the backing material, and the
felt travel at the same linear velocity, measured along what has
been designated in FIG. 3 as the X axis, at least at the point
where the needle roll and backing material are closest.
The foregoing is further illustrated in FIG. 3 where there is shown
a graphic illustration of a single needle so positioned relative to
the felt 33 and an associated card wire structure 29, the needle
and card wire structure moving from left to right such that at a
given position A, the needle 20 begins to enter felt being needle.
Position C is the position at which the portion of the needle 20
embedded in felt 33, the backing material 29 and the felt 33 will
be traveling at the same linear velocity along the X axis. The
needling sequence continues to position E where the needle 20 is
withdrawn completely from the felt 33. Throughout the needling
sequence the cut wire members 32 substantially retain their shape
and orientation under the axially oriented or vertical forces
imparted during the needling process. In addition, elongated
members 32 are susceptible to being moved from side to side around
their fixed ends 34 acting as pivots. For example, at position A,
the needle tip 35 has begun to penetrate the region occupied by the
felt 33. As the combination continues to move from left to right as
shown in FIG. 3, penetration of the needle 20 through the felt 33
is substantially complete by the time the combination has reached
position B at which position the elongated wire member 32 may be
caused to bend as a result of the impingement upon wire member 32
by needle 20. The force imparted upon the needle by the felt will
cause the needle 20 to deflect. At position B the angular
displacement of the needle 20 relative to the plane of the felt 33
is in a direction opposite that of the direction of movement of
felt 33. The magnitude of the deflecting force on the needle 20 is
a function of roll diameter and depth of needle penetration. For
example, the force and therefore needle deflection can be reduced
by increasing the diameter of the needle roll or the associated
backing roll or both rolls. As the sequence continues the end of
the needle 20 which extends through felt 33 may impinge upon the
bend other elongated wire members 32 and will begin to straighten
out such that at position C it will return to its normal
orientation. Similarly, the previously deflected wire members 32
will spring back to their normal orientation. As the needling
sequence continues past position C to position D, the needle 20
begins to withdraw from the felt 33, the bending or angular
displacement of the needle 20 relative to the plane of the felt 33
now being in the same direction as that in which felt 33 is moving.
In addition, the end of needle 20 which extends through felt 33 may
impinge upon and bend other elongated wire members 32 and will
again begin to straighten out such that at position E it will have
sprung back to its normal orientation. Similarly, the previously
deflected wire members 32 will spring back to their normal
orientation.
At this point, it should be noted that in order to overcome the
problems referred to above attendant to using a perforated-type
prior art backing plate, the elongated members 32 of the card wire
underlying the felt 33 must be free to move laterally to
accommodate the sweep of the needle tip region. The significance of
this is illustrated in FIG. 3a where it may be seen that if a
perforated backing plate where used as in prior art devices, it
would be necessary to have the angular displacement of the needles
take place about a pivot point 43 that is substantially in the
mid-plane 45 of the backing plate 47, since otherwise, the
perforated portion 48 of the backing plate 47 would have to be
substantially larger, with a consequent reduction in the ability of
the backing plate to withstand the pressure forces imparted during
the needling sequence. Not only does this cause an undesired
decrease in the effectiveness of the backing member, but also it
will be clear that it tends to increase the lateral force moments
impartd to the needle and that it further tends to increase the
size of the needle holes introduced in the felt 33. Furthermore, it
will be noted that in the prior arrangement depicted in FIG. 3A, of
necessity, the dimensions of the flared opening 50 imparted by the
angular displacement of the needle 20 in the felt are significantly
greater in terms of volumne displacement than are those in the case
of the present invention wherein there is no problem regarding
registration of needle tips and apertures in a backing plate. In
effect, it may be said that the backing member 29 of the present
invention provides a system of holes which, unlike those in a
backing plate, move to accommodate the angular sweep of the needle
tips.
It will be obvious that although not necessary the card wire member
can be made to pass through an arcuate path to address the
on-coming needles as, for example, by being placed around the
circumference of a roll. In the embodiment illustrated in FIG. 1
wherein the elongated members 32 are affixed to a backing roll 14,
the needle roll 12 and backing roll 14 are so positioned with
respect to each other that at least a portion of the needles 20 on
the needle roll 12 occupy the general region also occupied by the
elongated members 32 on the surface of the backing roll 14. To
permit variations in needling depth, one or both of the roll axes
are movable so that the rolls may be positioned closer together or
farther apart. Obviously, positioning the rolls closer together
will also have the effect of increasing the needling "zone", or
distance over which needles are inserted into the fabric at any
given point in time. Thus, for example, fibers 44 are laid onto the
outer surface of a papermakers felt 42 which has been rendered into
the form of an endless belt, by a fiber-laying device 46 of any of
a multitude of well-known designs such as a carder, batt former,
layer combination, or a blown fiber source, and is positioned about
the backing roll 14 and, in the case illustrated in FIG. 1, about a
carrier roll 16. The backing or the carrier roll, or the needle
roll, or even an associated slack takeup roll, or any combination
of them, may be driven to cause the rolls to revolve and,
therefore, the fabric 42 to move. As illustrated, the fabric 42
will be carried through the nip formed between the backing roll 14
and the needle roll 12 such that the needles 20 on the needle roll
12 will be caused to progressively plunge into and through and be
extracted from the papermarkers felt 42. In this manner, it is
possible to subject the felt to a substantial number of needling
passes in a very short length of time, because experiments have
demonstrated that the felt may be run through the needling nip at
speeds in excess of about 300 meters per minute.
Furthermore, because the diameters of the elongated members 32 of
the card wire structure 29 are small, and since, in terms of
needling practice, these diameters are analogous to the "land"
areas between the perforated holes on the backing plate of a
standard reciprocating needle machine, it is possible to have a
much more dense concentration of needles on the surface of the
needle roll than can be achieved on a standard needle board. For
example, the practical maximum density of needles on a needle board
as used in the industry is about 8,303/sg. meter, whereas
experimental machines embodying the present invention have been
used having a needle density of 13,830/sq. meter and it is thought
that this density might even be increased. Thus, through the
practice of the present invention, it is possible to perform a
high-speed needling operation from which the quality of needling
and the product produced thereby is very high and is clearly
acceptable to meet the standards of such difficult and demanding
products as papermakers felts.
It will be apparent that even though various backing roll -- needle
roll diameter combinations may be operative in the practice of the
present invention, it is desirable although not required for both
rolls to have large diameters; e.g., on the order of 120 cm or
more, since, obviously, the greater the diameter of one or both of
these rolls, the less relative movement there is between a given
needle point residing in the region of the card wire members 32,
and this further reduces the "working" of the needles through the
elimination of lateral moments of force even through it should be
understood that the degree of working is smaller diameters is
within acceptable limits since there will not be an untoward amount
of needle fatigue, bending, or breaking. Accordingly, backing roll
-- needle roll combinations having smaller diameters may also be
used. For example, backing roll -- needle roll combinations of as
small as 30 cm and 120 cm, respectively, have been shown to be
operative in the practice of the present invention. It also may be
desirable for the diameter of the backing roll to be equal to the
diameter of the needle roll.
EXAMPLE
A machine was constructed having a needle roll 122 cm in diameter,
to the surface of which were fitted felting needles which were
equilaterally triangular in cross-section, having barbs at the
corners of the triangles, to a needle density of 15 needles per 10
sq. cm of roll face. The needles were mounted perpendicular to the
roll face. Associated wire rolls were fabricated in two different
diameters; one 30 cm, and one 122 cm. On both of these wire rolls
the roll face was covered with card wire, the heights of the wire
filaments of which were approximately 2.5 cm in length. In this
piece of equipment, only the card wire roll was driven by an
outside source. The depth of needle penetration was adjusted as
desired by changing the center-to-center distance between the
rolls.
The felt was positioned about the card wire roll and over a third
idler roll which was movable to facilitate taking up slack in the
felt. Several felt samples were needled on this machine, using both
the 122 cm and the 30 cm wire roll.
It was observed that the rotary motion of this machine allowed
relatively high speed needling as compared to a standard
reciprocating needle loom. In standard needling procedures used in
the manufacture of papermakers felts it is typical to apply 12.8
g/sq. cm of fibers, and to perform work on felts of this type on a
regularly reciprocating needle loom would require 44.5 minutes. It
was found that the machine made in accordance with the present
invention, having approximately the same number of penetrations per
inch as in the aforesaid standard reciprocating needle loom, could
be operated at approximately 274.5 m/min., which completely needled
the felt in approximately 7.5 minutes. Thus, at a speed of 274.5
m/min. the needling productivity is approximately six times
greater.
No particular problems were apparent at 274.5 m/min., from which it
is clear that the running speed could be increased significantly.
In fact, on this same machine, another run was made at 457.2
m/min.
It was noted that the product of the present invention appeared to
have several different characteristics over those produced on
standard reciprocating needle looms. For example, one difference
was in the apparent size of the holes left in the felt by
penetration of the individual needles. Although the needle holes in
the felt produced on the machine of the present invention appear
slightly larger than those left by reciprocating needle looms,
apparently due to the changing angular path followed by the needles
during penetration, it was also noticed that the apparent bulk
density of the felts produced on the machine made in accordance
with the present invention was somewhat less than that produced by
a reciprocating needle loom. Without intending to be bound by any
theory, it appears that as needles are being pulled out of the
felt, they are still under a slight degree of lateral pressure so
that the point of the needle may tend to scrape the upper layer as
it clears the upper felt surface. Obviously, the degree to which
this occurs will be a function of the diameters of the rolls
used.
As noted above, both 122 cm and 30 cm wire rolls were used. It was
noticed that as the diameter decreased for a given running speed,
needle bending and breakage began to occur so that when the 30 cm
diameter roll was used, at a relatively high speed, the needling
had to be terminated in order to avoid serious damage to the needle
roll.
Various empirical measurements were made in the course of utilizing
the machine which embodied the present invention, during which it
was noted that the maximum load exerted on the rolls at their point
of contact with the felt being processed was in the neighborhood of
1.76 kg per linear cm, and that the horsepower requirements were in
the neighborhood of 0.0187 norsepower per 30.48 m per minute 2.5 cm
of face width.
Based on these experiments, it was estimated that the cost of a
loom embodying the present invention would be approximately 60
percent that of a commercially available reciprocating needle loom
of the same width.
With respect to the working characteristics of the papermaking
felt-type samples produced on machines embodying the present
invention, the following table shows the measured vertical flow
rate of such felts in liters per minute at various mechanical
loadings for various felt thicknesses made both on a reciprocating
needle loom and on the machine embodying the present invention.
______________________________________ Mechanical Felt Vertical
Loading Thickness Flow Rate KG/CM2 Milimeters Liters/Minutes
______________________________________ 17.5 1.45 55.3 Reciprocating
26.3 1.30 44.3 Loom 35.0 1.17 37.1 Sample 43.8 1.09 32.2 52.5 1.00
28.4 ______________________________________ 17.5 1.42 58.3 Present
26.3 1.24 46.2 Invention 35.0 1.14 39.4 Sample 43.8 1.09 34.1 52.5
1.00 29.1 ______________________________________
It should be obvious from the foregoing discussion that even though
the embodiments described above are in terms of structures having
two opposing rolls or cylinders, it is also possible to practice
the present invention in a wide variety of other configurations in
which the surface to which the needles are affixed and the surface
to which the backing members are affixed travel repeatedly through
closed travel paths which, in the aggregate of their constituent
flat and arcuate portions, cause the needles and the members to
pass through 360.degree. during each revolution, provided that at
some point along their paths of travel, at least a portion of the
needles reside among the elongated members of the backing members.
Included among them are a needle roll in combination with an
incline-decline plane carrying an endless belt of card wire as a
backing member, or an endless belt of card wire in combination with
an endless belt carrying needles, which combination converges at
some point along their paths of travel. Obviously, in these
embodiments of the invention, the "paths of travel" may not be the
true circles as in the case of the needle roll and the backing roll
being revolving cylinders, but instead may be elliptical or other
geometrically regular or even irregular closed loops in
cross-section. It is also within the contemplation of the present
invention to have a multiplicity of needle rolls in tandem arrayed
around around a common backing roll, whereby several combinations
of needle types and/or needling depths may be accommodated
sequentially on a given fabric in a single set up.
It is to be understood that the embodiments herein illustrated and
discussed, and the terms and expressions which have been employed,
are by way of illustration and not of limitation and that there is
no intention in using any of them to exclude any equivalents of the
features shown or described, or portions thereof, since it will be
recognized by those skilled in the arts that this invention may be
practiced in a wide variety of forms and embodiments without
departing from the spirit and scope of this invention.
* * * * *