Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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This invention relates to weft-inserting needles
for shuttleless weaving looms and especially to the exit weft-
inserting needles which are intended to take at the center of
the shed the weft thread which is presented thereto by an
entry weft-inserter.
Weft-inserters of a type which is already known
grip the thread by pinching or nipping between two stationary
surfaces which come together or between two surfaces, at least
one of which is elastically deformable.
In another known design, weft-inserters of the so-
called controlled nipper type comprise a stationary jaw which
is rigidly fixed to the needle and a moving jaw which is
urged elastically against the stationary ~aw in order to
clamp the threadr means for controlling the opening of the
moving jaw being provided in order to release the thread
when the needle is located in the vicinity of its end of
travel outside the shed.
Although the operation of these weft-inserters
proves satisfactory when it is necessary to grip and release -~
threads having constant characteristics (such as, for example,
structure, size and so forth), the same does not apply when
the characteristics of the thread vary either during a given
; operation on the loom or in the case of successive operations
on the same loom.
The aim of the present invention is to provide an
exit weft-inserting needle in which clamping of the thread
is improved and which makes it possible to operate in-
differently with threads having very different characteristics,
in particular in the case of operation in wefts of large sizeO
The invention is directed to a weft-inserting ;
needle having a controlled-opening nipper, the nipper being ;
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such as to comprise a stationary jaw rigidly fixed to the
needle as well as a pivotal moving jaw which is wrged by
elastic restoring means against the stationary jaw and rigidly
fixed to a projecting lever which is intended to cooperate
with a stationary opening-control member when the needle is
located in the vicinity of its end of travel outside the shed.
In accordance with the invention, the stationary jaw is in
the form of a hook and the moving jaw is provided at its
extremity with a pallet which is applied against the internal
flank of the hook, the top surface of said pallet being ~.
inclined at an angle with respect to the flank of the hook ~ .
at least in the closed position of the nipper, said angle being
open towards the rear of the needle and such as to form an
angle of nipping of the weft thread between the stationary
jaw and the moving jaw.
The arrangement just described already serves to
achieve improved clamping of the weft thread irrespective of
its size but, in accordance with a preferred embodiment of
the invention, means are provided for producing a tensioning -
effect on the thread or in other words for inserting the
thread between the jaws of the nipper.
In accordance with this preferred arrangement, one
of the two elements for clamping the thread in the nipper
(internal flank of the stationary hook or opposite face of
the movable pallet) has a longitudinal hollow zone such as a
groove, for example, whilst the second of these two elements
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has a corresponding projecting zone such as a rib or a tongue, ~
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for example, with the result that the weft thread is securely .held by a tensioning effect between the two jaws but can be
completely released so as to disengage from the nipper when :;
this latter opens at the end of travel of the exit needle
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outside the shed.
Further properties and advantages of the invention
will become apparent from the following description and from
the accompanying drawings which show by way of example and
not in any limiting sense a number of different embodiments
of an exit weft-inserter for a shuttleless weaving loom,
especially of the type described and illustrated inFrench
patent No 1,290,867 of February 14th, 1961 in the name of the
present Applicant.
In the accompanying drawings
- Fig. 1 is a longitudinal sectional view of an
exit needle in accordance with the invention ;
- Fig. 2 is an enlarged partial view of the nipper
of the needle shown in Fig. 1 ;
- Fig. 3 is a transverse sectional view taken along
line III-III of Fig. 2 ;
- Fig. 4 is a longitudinal sectional view of -~
another form of construction of a needle ; --
- Fig. 5 is a partial plan view of the moving jaw
of the nipper of the needle of Fig. 4 ;
- FigO 6 is a partial plan view of the nipper of ~ ;~
Fig. 2, this view being taken along line II-II and showing a ~ i
weft brake in the form of a blade-spring which can be fitted
on a needle in accordance with the invention.
The weft-inserting device for a shuttleless weaving
loom as illustrated in the drawings comprises a needle which
is generally designated by the reference 1 and a system for ~-
controlling the opening of the nipper as generally designated ~ ;
by the reference 2.
The needle 1 is driven in reciprocating motion along
the reed 3 of the weaving loom and is accordingly fitted with
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a shoe 4 which is intended to pass along the front face of
said reed. Motion is imparted to the needle 1 at the outer
extremity of this latter through the intermediary of a
coupling 5 of the ball-joint type, for example, by means of
a suitable system which does not form part o the present -
invention and a detailed description of which can be found
in the French patent cited earlier.
The needle 1 carries a nipper which is generally
designated by the reference 6 and constituted by a stationary
jaw 7 rigidly fixed to the body 8 of the nipper and by a
moving jaw 9 which is pivotally mounted on the stationary jaw
7 by means of a fulcrum-pin 10.
The nipper 6 is urged elastically towards its closed
position, namely the position of clamping of a weft thread 11,
by means of a spring 12, one extremity of which is applied
against a pin 13 and the intermediate portion of which bears
against an adjusting screw 14.
The moving jaw 9 is rigidly fixed to a projecting
lever 15 which is actuated in the direction of opening of the
nipper by the opening-control system such as a roller 16 when
the needle is located in the vicinity of its end of travel
outside the shed.
In accordance with known practice, the exit needle
grips at the center of the shed the weft thread which is
presented thereto by the entry needle and draws said thread
to the end of the shed at which the nipper opens.
In accordance with the invention, the stationary
jaw 7 has the shape of a hook and the moving jaw 9 is provided
at its extremity with a pallet 17 which is intended to co-
operate with the internal flank 18 of the pointed extremity
of the hook in order to clamp the weft thread.
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It can be seen in the figures that, in the closed
position of the nipper, the top surface of the pallet 17 is ~;
inclined at an angle with respect to the flank 18 of the hook,
this angle being open towards the rear end of the needle. As
shown in Fig. 1, this open angle makes it possible to grip
the thread as the exit needle moves backwards and produces a
pinching action on the thread when this latter is drawn by
the exit ne~dle. The angle of slope between the top of the
pallet and the flank of the hook can be adjusted, for example ~
by removal of metal/ depending on the nature of the yarn to ~ ~-
be woven. -
As can be seen more clearly in Fig. 2, the flank
of the hook is pierced by a longitudinal opening into which
the extremity of the pallet 17 penetrates to a partial extent
in the closed position of the nipper, said extremity being -
narrow and intended to constitute a tongue which cooperates
with said opening.
By virtue of this arrangement, there is added to the
effect of pinching of the thread between the stationary and `i~
moving jaws a tensioning or insertion effect which has been
shown diagrammatically in Fig. 3 and which is highly effective ~ -
for retaining the thread irrespective of the characteristics
of this latter.
When the nipper is actuated so as to initiate
opening or in other words when the lever 15 comes up against
the roller 16, the nipper opens and the pallet 17 moves to
a ~cufficient distance from the flank of the hook to ensure
that its projecting extremity completely disengages from the
slot 19, with the result that the thread is completely ~ ;
released irrespective of its size.
As can readily be understood, the through-slot 19
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formed in the hook can be replaced by a groove or any similar
hollow portion formed in the internal face of the flank of
the hook.
In the embodiment shown in Fig. 4, the hollow and
projecting portions formed in the stationary and moving jaws
are placed in the reverse order to that described in
connection with Figs. 1, 2 and 3. In other words, the
internal face 18 of the flank of the stationary hook carries
a projecting longitudinal rib 20 whilst the movable pallet 17
is hollowed-out in the form of a slot 21 (as shown in Fig. 5)
in which the rib 20 engages in the closed position of the
nipper. This arrangement also produces the favorable effect
of tensioning of the we-ft thread which has been described
earlier.
It is readily apparent that the hollow and project-
ing portions could also be constituted by more or less open
complementary V-profiles of the flank of the hook and of the
pallet. ~ ~s
An exit needle in accordance with the invention can
20 be completed by a weft brake constituted by a blade-spring 22
(shown in Fig. 6) which is mounted on one of the faces of the
hook 7 and applies the thread against the body of the hook
while braking this latter. As an advantageous feature, the
blade-spring 22 can be retained by the rivet which serves as
25 a fulcrum-pin 10 for the moving jaw in the stationary jaw.
As will readily be apparent, the invention is not - -
limited to the embodiments hereinabove described and illus-
trated in the accompanying drawings but, depending on the `
applications which may be contemplated, can cover a broad
range of alternative embodiments within the capacity of those
379 ~:
versed in the art without thereby departing either from the -
scope or the spirit of the invention.
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