Description

Frame having needle lamellae and guide lamellae

[oooi] The invention relates to a frame having successively arranged needle lamellae for ground threads and guide lamellae for leno threads, in which frame the guide lamellae are bordered at both ends in each case with a profile and the shorter needle lamellae are bordered at only one end with one of the profiles and are provided at their free end with a guide eye for ground threads.

[0002] It is known to provide frames having needles for ground threads for leno weaving machines (WO 02/04723 At, WO 2007/025765 A1). The ground threads cooperate with leno threads which are delivered alternately onto one side and the other of the needles. If the needles are arranged relatively closely to one another in order to weave a high-density leno fabric, or in the case of high speeds, there is the risk that the leno threads do not come onto the correct side of the needles because of vibrations of the needles. In order to avoid this risk, it is known to raise the needles between guide lamellae which ensure that the leno threads always come onto the correct side of the needles (CH 535 304). It is likewise known (US 14 35 615) to provide the needle lamellae with guide eyes which are arranged between lamellae serving for guidance. In order to ensure that the leno threads also come between the guide lamellae and the needle lamellae, in this type of construction the needle lamellae are provided, in the region of the guide eyes for the ground threads, with embossings which hold the needle lamellae at a distance from the guide lamellae, so that a leno thread can come between guide lamellae and needle lamellae.

[0003] In order to deflect the ground threads as little as possible within the guide eyes of the needle lamellae, it is also known (WO 02/101 131) to rotate the needle lamellae in the region of the guide eyes, so that a free passage is obtained.

[0004] In a special type of construction of a frame (US 687 541), it is known to provide lamellae with loops at their end and to slip them onto support bars. In this case, shorter and longer lamellae are used. The shorter lamellae, which, if appropriate, are slipped with only one end onto a support bar, are provided with guide eyes which receive threads. The guide eyes consist of a relatively narrow recess, of which the legs delimiting the recess in the running direction of the

threads are bent out or offset in opposite directions, so that a free passage is provided. These bent-out legs abut against the adjacent lamellae having no guide eyes.

[0005] The object of the invention is to provide a frame of the type mentioned above, which allows, on the one hand, to provide guide eyes with a large free cross section and, on the other hand, to centre the needle lamellae between the guide lamellae such that the leno threads can always come alternately onto the correct side of the needle lamellae.

[0006] This object is achieved in that the needle lamellae are provided, for forming the guide eyes, with a recess delimited with respect to the narrow sides or lateral edges by a front leg and a rear leg which are bent in opposite directions out of the plane of the lamellae in such a way that a free passage is pre- sent in the running direction of the ground threads.

[0007] It is ensured that the bent-out portions of the legs which delimit the recess for forming guide eyes are shaped and/or arranged such that a relative movement between the needle lamellae and the guide lamellae is possible, in order to deliver the leno threads past the guide eyes onto one side or the other of the needle lamellae.

[0008] Further features and advantages of the invention may be gathered from the following description of the embodiments illustrated in the drawings and from the dependent claims.

Fig. 1 shows a front view of a heddle frame according to the invention,

Fig. 2 shows a part-view of a frame according to Fig. 1 on a somewhat enlarged scale,

Fig. 3 shows a perspective part-view of a frame according to Fig. 1 or 2,

Fig. 4 shows a section through the frame according to Fig. 2 along the line IV-IV,

Fig. 5 shows a view in the direction bf the arrow V of Fig. 4 on an enlarged scale,

Fig. 6 shows a section, similar to Fig. 4, through a modified embodiment,

Fig. 7 shows a view in the direction of the arrow VII of Fig. 6,

Fig. 8 shows a section, similar to Fig. 6, through a modified embodiment,

Fig. 9 shows a section through a needle strip for ground threads, and

Fig. 10 shows a further device for the holding of lamellae.

[0009] Fig. 1 shows a frame with an upper profile 10, with a lower profile 11 and with two side profiles 12 and 13. The frame contains alternately successively arranged guide lamellae 14 for leno threads and needle lamellae 15 for ground threads. The guide lamellae 14 are arranged with their two ends in the profiles 10, 11 , as will be described in detail later. By contrast, the needle lamellae 15 are arranged and held with only one end in the profile 10. The guide lamellae 14 and the needle lamellae 15 face one another with their flat sides. Their narrow sides or lateral edges running transversely thereto lie essentially in one plane, parallel to warp threads during operation.

[ooio] As can be seen from Figs. 2 to 5, the needle lamellae 15 are provided in the region of their ends with guide eyes 16, through which in each case a ground thread is guided. In order to form the guide eyes 16, the needle lamel- lae 15 are provided in the region of their ends with an approximately square recess 17 which has rounded corners. The recess 17 extends approximately over two-thirds of the width of the needle lamellae 15. The recess 17 is delimited in the running direction of ground threads, in the direction of the narrow sides, by means of legs 18, 19. These legs 18, 19 are bent in opposite direc- tions out of the plane of the lamellae, so that, in the running direction of ground threads, a free passage 20 is provided, through which the ground threads can run, without being appreciably deflected. In the exemplary embodiments illustrated, the width B, C of the legs 19, 18 delimiting the recess 17 corresponds at most to a quarter of the width A of the needle lamellae 15. In the exemplary embodiment illustrated, the recess 17 has in the longitudinal direction L of the needle lamellae 15 a dimension which corresponds approximately to their dimension.

[ooii] As can be seen particularly from Fig. 4 and 5, the legs 18, 19 are not bent out over their entire height, but only over a portion which amounts to about half their length. The inner edges of the recess, which are illustrated by dashes in Fig. 5, are rounded. In the embodiment according to Figs. 4 and 5, the legs 18, 19 of the needle lamellae 15 are bent out only to an extent such that they can maintain a distance from the guide lamellae 14 which is sufficient to make it possible to guide a leno thread between the guide eyes 16 and the guide lamellae 14 along the needle lamellae 15. In an exemplary embodiment, the thickness of the guide lamellae 14 amounts to approximately 0.2 mm and the thick- ness of the needle lamellae 15 to approximately 0.4 mm. The protuberance between two mutually opposite margins of the guide lamellae 14 therefore amounts to at least 0.9 mm, preferably at least 1 mm.

[0012] In the embodiment according to Figs. 6 and 7, the width of the guide lamellae 14' in the region of the guide eyes 16 of the needle lamellae 15' is narrower than the recess 17 in the direction of the lamella width. It is thereby possible to arrange the guide lamellae 14' at a shorter distance from one another and from the needle lamellae 15' and, nevertheless, to allow the leno threads to move past the guide eyes 16 between the guide eyes 16 and the guide lamellae 14'. In the exemplary embodiment illustrated, the dimension of the recess 17 of the needle lamellae 15' transversely to the longitudinal direction L is greater than the width which the guide lamellae 14' have in the region of the recess 17.

[0013] In this embodiment, in order to prevent the needle lamellae 15' from abutting against the guide lamellae 14', thereby preventing a leno thread from being guided past the needle lamella 15' on the desired side the needle lamellae 15' are provided with embossings 21 , 22, as indicated in Fig. 6 which ensure that a gap, sufficient for the introduction of a leno thread, is maintained between the needle lamellae 15' and the guide lamellae 14'. In a modified embodiment, corresponding embossings are provided on the guide lamellae 14'. In a further- modified embodiment, embossings 21 , 22 of this type are provided at the free end of the needle lamellae 15'.

[0014] Fig. 8 shows a section, similar to Fig. 4, through a further modified embodiment. In this embodiment, the guide lamellae 14" are provided with embossings 28, 29, which delimit a relative movement of the needle lamellae 15 with respect to guide lamellae 14". This likewise ensures that a gap is maintained between the needle lamellae 15 and the guide lamellae 14". In the ex-

emplary embodiment illustrated, the embossings 28, 29 are configured as legs 28, 29, which delimit an orifice 27 laterally.

[0015] The guide lamellae 14, 14', 14" and the needle lamellae 15, 15' are arranged in the profiles 10, 11 in such a way as is known, for example, from the arrangement of lamellae of reeds (WO 99/64654 A1). The ends of the guide lamellae 14, 14', 14" at the top in Fig. 4 and 6 are profiled. They are arranged at the desired distance from one another by means of a helically coiled spring 23 or a correspondingly coiled binding wire and are inserted into the profile 10 which has a U-shaped cross section. A curing plastic is cast into the profile 10 and fixes the guide lamellae 14, 14', 14" and the needle lamellae 15, 15' in the predetermined position. The guide lamellae 14, 14', 14" are enclosed at their opposite ends by a profile 11 into which a curing plastic is likewise inserted.

[0016] The helically coiled spring 23 or the correspondingly coiled binding wire may be left in the finished structure or be removed after the curing of the plastic. Self explanatory, it is also readily possible to connect the lamellae 14, 14', 14", 15, 15' to one another in another way before they are inserted into the profiles 10, 11. For example, it is possible to press into the recesses at the ends of the lamellae bars, which provide a non-positive connection at least.

[0017] In the exemplary embodiments illustrated, needle lamellae and guide lamellae are arranged alternately. Embodiments may also be envisaged, however, in which two or more guide lamellae are arranged next to one another to which two needle lamellae follow laterally.

[0018] The needle frame, illustrated in Fig. 9, for ground threads of a leno weaving machine possesses lamellae 15 provided with guide eyes 16 for ground threads and supporting lamellae 14 arranged between them. The lamel- lae 15 are provided in the region of the recess 17 with oppositely directed indentations 18, 19 which run in each case to the narrow sides and which form, for ground threads, a free passage running transversely with respect to the lamella 15. The inversely arranged indentations are of a size such that they in each case touch the adjacent supporting lamellae 14.

[0019] The lamellae 14 and 15 are connected to one another to form a device, for which purpose the end regions lying opposite the recess 17 are connected to one another by means of recesses 30 and bars 31 pressed into them.

In the exemplary embodiment according to Fig. 9, the lamellae 14, 15 are also aligned with one another, in the region of the ends provided with the recess 30, by means of a helically coiled spring.

[0020] The upper end of the lamellae 14, 15 is bordered with a profile 10. The lamellae 14, 15 which are connected to the bars 31 in this region are connected to the profile 10 by means of a curing plastic material. By means of this profile 10, the needle frame formed from the lamellae 15, 14 is fastened in a leno weaving machine. The opposite ends of the lamellae 14 are enclosed in a profile 11. The lamellae 14 are connected to this profile 11 by means of a curing plastic.

[0021] The needle frame according to Fig. 9 for the ground threads is conventionally used in a leno weaving machine together with one or more perfo- rated strips for the leno warp threads.

[0022] Fig. 10 shows a portion of a further device for the holding of lamellae 15. The lamellae 15 are configured similarly to the lamellae according to Fig. 9. The upper end of the lamellae 15 is enclosed in the profile 10 and is connected in this region to bars 31. The recesses 30 for the bars 31 have a dovetail- shaped configuration. By means of an undercut thereby provided, a positive connection is also achieved in addition to the non-positive connection. Other undercuts may be provided for this purpose. The bars 31 illustrated are in this case deformed elastically and/or plastically.

[0023] Connections of this type may also be employed for successively arranged lamellae of a reed, for example of a reed for gripper weaving machines or airjet-weaving machines and similar devices.