Ribbon loom

The ribbon loom comprises a weft thread insertion needle arranged at one side of the warp threads for inserting at least one loop or bight of a weft thread into the weaving or loom shed formed by the warp threads. The weft thread insertion needle has a longitudinal slit throughout almost its entire length. The weft thread insertion needle is also provided with a hook which, exterior to the longitudinal slit, is located at least approximately in the plane of motion of the weft thread insertion needle and is oriented toward the thread guide for the weft threads. The tip or point of the hook is arranged in the proximity of the free end of the weft thread insertion needle and points toward such free end. This results in an especially slender design of weft thread insertion needle and a reliable engagement of the weft thread or threads on the hook solely by means of the thread guide without any supplementary or auxiliary device.

BACKGROUND OF THE INVENTION 
The present invention broadly relates to power looms and, more 
specifically, pertains to a new and improved construction of a ribbon or 
tape weaving machine or loom for weaving ribbons or tapes or the like. 
Generally speaking, the ribbon loom or weaving machine of the present 
invention is of the type comprising a weft thread insertion needle 
arranged at the side of the warp threads for inserting a weft thread loop 
or bight into the weaving shed. The weft thread insertion needle has a 
longitudinal slit or slot extending over substantially the entire extent 
of its length for accommodating therein at least two weft threads and also 
has a hook structure or hook arranged in the region of its free needle 
end. The hook structure is provided with a tip or point oriented in the 
direction of the free end of the weft thread insertion needle. Thread 
guides serve for holding the at least two weft threads in selected and 
non-selected or idle positions, such that the weft threads can be picked 
up by the weft thread insertion needle and inserted or fed into the 
weaving or loom shed. 
A ribbon loom or weaving machine of this type is known from German Patent 
No. 2,400,101. In such ribbon loom, the plane of the opening of the 
longitudinal slit of the weft thread insertion needle is arranged 
transverse to the plane of motion of such weft thread insertion needle and 
the hook is disposed within the longitudinal slit on an edge of an arm or 
leg of the material surrounding the slit. Although very good results have 
been obtained with this weft thread insertion needle, it has the 
disadvantage that guide pins are required to guide the weft threads so as 
to ensure the proper insertion of one or more of them. The further 
disadvantage arises that the weft thread can jump off the hook. Due to the 
arrangement of the hook within the longitudinal slit, it is furthermore 
necessary that the weft thread insertion needle have a relatively large 
width which, in turn, requires a relatively large weaving shed. The 
greater displacements or sweeps of the corresponding warp harnesses 
necessary to open the weaving shed require correspondingly larger drive 
means whose rotational speed is limited. This limits the performance or 
output of such ribbon looms. 
SUMMARY OF THE INVENTION 
Therefore, with the foregoing in mind it is primary object of the present 
invention to provide a new and improved construction of a loom or weaving 
machine which does not have associated with it the aforementioned 
drawbacks and shortcomings of the prior art constructions. 
Another and more specific object of the present invention aims at providing 
a new and improved construction of a ribbon loom or weaving machine of the 
previously mentioned type in which the hook is arranged exterior to the 
longitudinal slit or slot of the weft thread insertion needle and at least 
approximately in the plane of motion of the weft thread insertion needle 
and oriented toward the thread guide means. 
Yet a further significant object of the present invention aims at providing 
a new and improved construction of a power ribbon loom of the character 
described which is relatively simple in construction and design, extremely 
economical to manufacture, highly reliable in operation and affords a high 
output, not readily subject to breakdown and malfunction and requires a 
minimum of maintenance and servicing. 
Now in order to implement these and still further objects of the invention, 
which will become more readily apparent as the description proceeds, the 
ribbon loom of the present invention is manifested by the features that 
the hook structure or hook is arranged exterior to the longitudinal slit 
at least approximately in the plane of motion of the weft thread insertion 
needle and is oriented or directed toward the thread guides for the warp 
threads. 
By virtue of the fact that the hook is arranged externally of the 
longitudinal slit or slot of the weft thread insertion needle and at least 
approximately in the plane of motion or movement of the weft thread 
insertion needle and is oriented or directed toward the thread guides, the 
hook does not limit or define the opening of the longitudinal slit, so 
that the latter may be made considerably more slender or narrower. This 
means that only the guidance of the weft thread or threads need be taken 
into consideration. A narrower longitudinal slit or slot results in a more 
slender weft thread insertion needle. This means that the weaving shed 
need not be opened so wide and therefore that smaller sweeps or 
displacements of the corresponding warp harnesses are sufficient. This 
permits the use of smaller and faster drive means which can increase the 
performance or output of such ribbon looms. 
The arrangement of the hook externally of the longitudinal slit and 
oriented in the direction of the thread guides as well as the accurate 
guidance of the weft threads within the longitudinal slit make the use of 
guide pins or the like in such ribbon or tape looms superfluous. Reliable 
operation of the weft thread insertion needle is still assured by the 
improved thread guidance. Furthermore, an undesirable disengagement or 
jumping off of the weft threads from the hook of the weft thread insertion 
needle is avoided. 
In the new and improved arrangement, the plane of the opening of the 
longitudinal slit or slot of the weft thread insertion needle can coincide 
with the plane of motion of the needle. This results in an especially flat 
design of the weft thread insertion needle which, in turn, results in a 
particularly small weaving shed and consequently permits a very high 
performance or output of the ribbon loom or weaving machine. On the other 
hand, the weft threads are subjected to a very taut guidance in the 
longitudinal slit, so that there are limits to crossing a weft thread to 
be inserted into the shed with another weft thread in the selected 
position. Compromise designs of the weft thread insertion needle are also 
possible in which the plane of opening of the longitudinal slit forms an 
angle of between 0.degree. and 90.degree. to the plane of motion of the 
weft thread insertion needle. However, an embodiment of the ribbon loom in 
which the plane of opening of the longitudinal slit is transverse to the 
plane of motion of the needle is particularly advantageous, since in this 
case the weft threads can more easily cross one another in the 
longitudinal slit. In this arrangement, the hook can be disposed on the 
upper or the lower arm of the weft thread insertion needle, according to 
whether the thread guides move upwardly or downwardly in their travel to 
the selected position. 
A particularly slender and stable construction of the weft thread insertion 
needle results when at least one arm or leg of the needle which carries 
the hook is substantially rectangular in cross section and its major axis 
lies substantially in the plane of motion of the needle and the hook is 
preferably formed by an acute-angled step in the width of the arm, i.e. by 
a step-like taper or constriction of the front portion of the weft thread 
insertion needle. This permits the other hook-free arm or leg of the weft 
thread insertion needle to be lightly constructed, for instance preferably 
from a piece of wire.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Describing now the drawings, it is to be understood that only enough of the 
construction of the ribbon or tape weaving machine or loom has been 
depicted therein as is needed for those skilled in the art to readily 
understand the underlying principles and concepts of the present 
development, while simplifying the showing of the drawings. Turning 
attention now to FIGS. 1 to 4, it will be seen that the exemplary 
embodiment of ribbon or tape weaving machine or loom comprises a support 
plate 4 mounted on a loom frame 2 for supporting and guiding the woven 
goods or fabric 6. A breast roll 8 is mounted at the outer or front end of 
the support plate 4. The woven goods 6 pass over the breast roll 8 to a 
conventional fabric or woven goods roll not particularly shown in the 
drawings. The inner or rear end of the support plate 4 guides and retains 
the fabric 6 at the beat-up edge or cloth fell 12. A suitable warp thread 
supply device feeds the warp threads 14 through a shed-forming device 16 
to the beat-up edge or cloth fell 12. 
The loom frame 2 is provided with a not particularly shown but suitable 
drive mechanism which drives a shaft 18 in rotary oscillation. An arm or 
arm member 20 is mounted on the shaft 18 and carries a weft thread 
insertion needle 22. The weft thread insertion needle 22 introduces or 
inserts one or more weft thread loops or bights 24 into the weaving shed 
26 formed by the warp threads 14. On the side of the weaving shed 26 
opposite the weft thread insertion needle 22, a knitting or chaining 
needle 28 driven with a to-and-fro motion is arranged to lock or tie the 
weft thread loops or bights 24 fed in by the weft thread insertion needle 
22. Sequential or successive weft thread loops or bights 24 can be chained 
with one another or can be knitted or tied by an auxiliary thread. A 
weaving reed 32 mounted on a pivot or pivotal arm 30 serves to beat-up the 
inserted weft thread loops or bights against the beat-up edge or fell 12. 
As best seen by referring to FIG. 3, the weft thread insertion needle 22 is 
provided with a longitudinal slit or slot 34 whose plane of opening is 
transverse to the plane of motion or movement of the weft thread insertion 
needle 22. This longitudinal slit 34 is formed by two surrounding arms or 
legs 36 and 48, the upper arm 36 having a substantially rectangular cross 
section whose major axis lies in the plane of motion of the needle. A hook 
or hook member 40 is formed on the upper arm 36 in proximity to the free 
end of the weft thread insertion needle 22. This upper arm 36 is provided 
with a segment or constriction 38 reduced in width in respect to the cross 
section of the arm by an acute-angled step or step-like taper forming the 
hook 40. The tip or point 42 of the hook 40 is oriented toward the free 
end of the weft thread insertion needle 22 and also toward thread guides 
44a and 44b for the weft threads 46a and 46b, respectively. 
The lower arm or leg 48 of the weft thread insertion needle 22 bordering 
and limiting the longitudinal slit or slot 34 is less rigid or sturdy than 
the upper arm or leg 36 and is preferably formed of a wire 48a. A 
plurality of weft threads 46a, 46b can be guided in the longitudinal slit 
or slot 34. In the drawings, only two weft threads are shown. In the 
non-selected or idle position of the thread guides 44a, 44b, the weft 
threads 46a, 46b lie upon the lower edge of the longitudinal slit 34, i.e. 
on the lower arm or leg 48, as is visible in FIG. 3 and especially visible 
for weft thread 46b in FIG. 4. This places the weft threads 46a, 46b 
beyond the engagement region of the hook 40. If a thread guide 44a or 44b 
(specifically thread guide 44a in FIG. 4) is now raised into the selected 
position, the corresponding weft thread 46a or 46b (specifically weft 
thread 46a in FIG. 4) is guided diagonally upward into the engagement 
region of the hook 40. The weft thread that is momentarily engaged by the 
hook 40 is fed into the weaving shed 26 in the form of a loop or bight 24 
by the weft thread insertion needle 22 and is held and tied or stitched by 
the knitting needle 28 on the opposite side of the woven ribbon or tape or 
the like. 
To select the weft thread to be inserted into the shed 26 from a plurality 
of weft threads 46a, 46b guided in the longitudinal slit 34, any known 
programmable device can be provided. This can be, for instance, a cam 
device or similar structure. The weft thread selection can also be made by 
the shed forming device, for instance a heald machine, a single heddle 
control or a Jacquard loom. The latter is shown in the present 
illustrative example and its heddle set or buddle 50 is visible, guided 
through the holes of a stringing board 52 or the like. 
FIG. 5 shows a further embodiment of weft thread insertion needle 54 which, 
in contrast to the weft thread insertion needle 22 of FIGS. 3 and 4, is 
provided with a longitudinal slit 56, the plane of whose opening lies in 
the plane of motion of the weft thread insertion needle 54. A hook or hook 
member 60 is arranged on the rearward arm or leg 58 defining one side of 
the longitudinal slit 56. The hook 60 is arranged and structured 
analogously to the hook 40 of the weft thread insertion needle 22. The 
forward arm or leg 62 defining or bounding the other edge of the 
longitudinal slit or slot 56 of the weft thread insertion needle 54 is, in 
this embodiment, likewise structured to be less rigid or sturdy than the 
rearward arm 58. The operation of this weft thread insertion needle 54 in 
inserting the weft threads 46a and/or 46b corresponds to the procedures 
described above. 
Still further embodiments of the weft thread insertion needle are possible. 
For instance, combined forms of the weft thread insertion needles 22 and 
54 are conceivable, i.e. the plane of the opening of the longitudinal 
slits can, as required, be oriented at an angle varying between 0.degree. 
and 90.degree. to the plane of motion of the weft thread insertion needle. 
Furthermore, the weft thread insertion needle need by no means be curved. 
Straight needles having straight-line to-and-fro motions are also 
possible. 
While there are shown and described present preferred embodiments of the 
invention, it is to be distinctly understood that the invention is not 
limited thereto, but may be otherwise variously embodied and practiced 
within the scope of the following claims.