Note: Descriptions are shown in the official language in which they were submitted.
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The present invention relates to a felting needle,
which is used for felting operations, and for proces~ing man-
made fibers, floor coverings, artificial leathers, and the like,
Felting needles of the prior art, made without streng-
thening of the rear portion of the forward operating part thereof
and without radius rounding of the surface of the barb or barbs
were very often broken during a felting operation. This known
construction of the barbs has caused the damaging of the fibers
by being cut by the edges of the barbs. The breaking of the
needles means that the needles must be changed in the basic disk
in which they are mounted, and the breaking of the needle also
caused mechanical damage to the surface of the manufactured floor
covering being worked upon. These disadvantages of prior art
felting needles have caused the slowing down of manufacture of
floor coverings, and the resulting floor covering was not of
high quality, usually when a needle broke the floor covering
had to be designate~ a "second", that is, of lower than ideal
quality.
These disadvantages are overcome by the use of felting
needles according to the present invention comprising a forward
operating part having a forward barbed portion and a smooth rear
portion, at least one barb on the forward portion, the barb having
a groove and a projection from the body of the needle rearwardly
of the groove, the groove and projection forming the barb, the
rear portion of the operating part of the needle having a cross-
sectional area which is about 10 - 20% greater than that of the
forward portion of the operating part of the needle, the base
surface of the groove, the front suxface of the barb, and the
root of the barb being radius rounded.
As above mentioned, the smooth rear portion of the
forward operating part of the felting needle is made stronger
than the forward barbed portion of the foward operating part
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of the needle, which is provided with one or more barbs. The
strengthening of the smooth rear portion of the forward operating
part is about 10 - 20% (advantageously about 16%) as compared
to the barbed forward portion of the operating part is accom-
plished by making the rear portion of the operating part with a
cross sectional area which is 10 - 20% (preferably about 16%)
greater than that of the barbed portion of the forward operating
part, and by making the edges of the barbs rounded on a radius.
Thus, the barbs have a radius rounding of the base surface of
the groove which leads to the barb proper, and a radius rounding
of the front surface of the barb as well as of the root of the
barb. Felting needles made in accordance with the invention are
especially characterized by their high durability, which results
from the strengthening of the rear operating part of the felting
needle and from the radius rounding of all surfaces and edge~
of the barbs.
Felting needles in accordance with the invention are
much more efficient than previously known felting needles, with
the high durability of felting needles according to the inven-
tion economies of manufacture result and all products Inade withsuch needles have a higher quality than that of products made
by the use of known prior art felting needles.
The invention will be more readily understood by refer-
ence to the accompanying drawings in which: -
Fig. 1 is a front elevation of a first embodiment ofa felting needle in accordance with the invention,
Fig. 2 is a detail of a barb on the needle of Fig. 1,
the ~iew being in perspective;
Fig. 2a is a fragmentary view in plan of the barb of
Fig. 2;
Fig. 3 i~ a view in transverse section of the radius
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proper, and of the front surface of the barb on the needle,
the section being taken along the line 3 - 3 in Fig. 2a;
Fig. 4 is a view in cross section of the felting
needle taken along line 4-4 in Fig. l;
Fig. 5 is a view in ~ross section of the felting
needle taken along line 5 - 5 in Fig. l; and
Fig. 6 is a complete view of a felting needle in
accordance with the invention.
Turning now to the drawing, and particularly Figs. 1 -
5 incl., the felting needle A there shown has a forward operatingpart 1, 2, portion 1 being provided with a number of barbs , and
a smooth rear portion 2 of appreciably larger cross section.
As shown in Figs. 4 and 5, both of portions 1 and 2 are of
generally triangular cross section. A barb generally designated
3 is shown in detail in Figs. 2 and 2a. A groove having a
rounded base surface 4 is cut into the surface along an apex
of the triangular cross section of the needle. Such groove is
inclined rearwardly and toward the axis of the needle at an
angle 7 (Fig. 2). The base surface 4 of the groove, the front
surface of the barb proper 5, and the root 6 of the barb are
all curved on a radius as shown, that is, the surfaces of the
barbs are rounded in transverse section. The shape of the
rounding is well shown in Fig. 3.
The strengthening oonstruction of the rear portion 2
of the forward operating part 1, 2 of the felting needle prevents
the bending of the needle, and thus it is insured that the tip
at the forward end of the felting needle passes through the
openings in the disk and so the felting needles of the inven-
tion are not often broken. Although sometimes the felting
needles of the invention are broken, they are always broken
in the area between the weaker barbed portion 1 and the thicker,
stronger smooth rear portion 2, that is, in the area ~ between
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the forward barbed portion 1 and the rear portion 2 of the
forward operating part 1, 2. Area 8 is of generally frusto-
pyramidal shape as shown.
The purpose of the radius rounding of the surfaces 4
and 6 and the rounded edges of the barb proper 5 is to prevent
damaging the fibers by cutting them, and also results in a higher
productivity of the felting machines. With this construction
of the surfaces and edges of the barb, the barbs last longer.
Because of that, the depth of the barb and the ease of punching
the material being felted by the needle do not change appreciably
over very substantial periods of use of the felting needle.
As shwon in Fig. 6 the felting needle has a shank
portion 9, 10, 11 rearwardly of the forward operating part 1,2.
Parts 10 and 11 of the shank are of circular cross-section,
part 11 being bent at 90 with respect to part 10. Part 9
is generally of frusto-conical shape, serving as a zone of
transition from the triangular cross-section of portion 2 and
the larger, circular section of part 10 of the shank. However
this shank portion is known in the art and does not form part
of the present invention.
With the described construction of the barb of the
felting needle of the invention there result a higher durability
of the needles, an increase of about 60 - 80% in useful life,
and a better working-out of the fibers. As above stated, the
higher efficiency of the felting needle of the invention results
from its strengthening in the rear operating part 2 thereof and
by using rounded surfaces and edges at the barb on the forward
part 1 thereof.
The felting needle of the invention has been extensi-
vely tested and used by Czechoslovak national enterprises inthe production of floor coverings, felting pads of the plastics
industry, and for further felting products in gen~ral.
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Thus, RETEX, narodni podnik, of Ivandice, Czechoslova-
kia has tested felting needles in accordance with Figs. 1 - 5
incls., on most difficult work, the joining the reverse side
and the face of material weighing substantially about 960 -
1000 g/~
During the test work were also used prior art needles
made by a well-known company. One half of the tested material
was worked with the prior art felting needles and the second half
of the test~d material was worked with felting needles A of the
present invention.
In the test, which was done by the Research Institute
VUV of Brno, the samples were tested according to the norm
for these methods.
Since felting machines when using felting needles A
were quiet, it was therefore possible to increase the speed of
production of these felting machines about 6 - 7 percent. Even
after increasin~ the speed, the goods were of high quality.
8reaking of felting needles A is lower, and conse-
quently the consumption of such felting needles was lower. The
technological limit of consumption of the prior art felting
needles was 0.86 felting needle /1 m , whereas the consumption
of needles A was 0.42 felting needle / 1 m2.
The new shape of the barbs with rounded surfaces,
causes less damage to felting needles A and better interlacing
of the felting fibers. This effect is in consequence with high
production speed and it gives good results in regard to abrasion
and piling effects.
The invention can be used in all kinds of felting
needles, which are used for different kinds and thicknesses of
working materials. It is understood that felting needles in
accordance with the invention will differ as to length, the size
of their cross section, and the number of the barbs on each
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needle depending upon the material being worked upon.
Although the invention is illustrated and described
with reference to two preferred embodiments thereof, it is to
be expressly understood that it is in no way limited to the
disclosure of such preferred embodiments, but it is capable Or
numerous modifications within the scope of the appended claims.
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