Classifications

• • D—TEXTILES; PAPER
  • D03—WEAVING
  • D03D—WOVEN FABRICS; METHODS OF WEAVING; LOOMS
  • D03D47/00—Looms in which bulk supply of weft does not pass through shed, e.g. shuttleless looms, gripper shuttle looms, dummy shuttle looms
  • D03D47/28—Looms in which bulk supply of weft does not pass through shed, e.g. shuttleless looms, gripper shuttle looms, dummy shuttle looms wherein the weft itself is projected into the shed
  • D03D47/30—Looms in which bulk supply of weft does not pass through shed, e.g. shuttleless looms, gripper shuttle looms, dummy shuttle looms wherein the weft itself is projected into the shed by gas jet
  • D03D47/3006—Construction of the nozzles
  • D03D47/302—Auxiliary nozzles
• • D—TEXTILES; PAPER
  • D03—WEAVING
  • D03D—WOVEN FABRICS; METHODS OF WEAVING; LOOMS
  • D03D47/00—Looms in which bulk supply of weft does not pass through shed, e.g. shuttleless looms, gripper shuttle looms, dummy shuttle looms
  • D03D47/27—Drive or guide mechanisms for weft inserting
  • D03D47/277—Guide mechanisms
  • D03D47/278—Guide mechanisms for pneumatic looms
• • D—TEXTILES; PAPER
  • D03—WEAVING
  • D03D—WOVEN FABRICS; METHODS OF WEAVING; LOOMS
  • D03D49/00—Details or constructional features not specially adapted for looms of a particular type
  • D03D49/60—Construction or operation of slay
  • D03D49/62—Reeds mounted on slay

Definitions

• the invention relates to an open weft picking channel made by profile dents of a beat-up reed of a pneumatic weaving machine with built-in auxiliary jets whose outlet apertures reach into the width of the weft picking channel and in which at least a part of the weft picking channel has a constant profile.
• the weft In pneumatic weaving machines, the weft is inserted into the shed of warp threads by means of a main jet situated on its entry side. In the shed, the weft is led through a picking channel consisting either of orifices or of profile dents of a beat-up reed. In modern high-speed weaving machines, auxiliary jets acting on the face of the weft in process of picking are arranged along the length of the weft picking channel. The profile dents of the beat-up reed are fitted with a pair of protrusions creating a bounded weft picking channel open in the direction of the fabric being produced.
• An open weft picking channel consisting of profile dents of a beat-up reed has been disclosed for instance in the CS patent Nr. 219 281 showing several shape modifications of the dents.
• the protrusions of the profile dents of the beat-up reed create here an open weft picking channel shaped substantially as a lying U.
• the profile dents thus shaped are replaced by dents of a different shape with the upper protrusion only.
• the weft picking channel is in this section bounded only by two sides, i. e., by the upper side and by the back beat-up side. In a variant, they are replaced by only flat beat-up dents.
• the profile reed with an open weft picking channel has in the area of the projection of the auxiliary jets situated alternately flat dents and dents fitted with the upper protrusion. Consequently, the cross section of such weft picking channel is constant, with the lower side or possibly also the upper side, consisting of reed dents, being omitted only in the area of the auxiliary jets.
• the patent DE No. 3,740,666 has disclosed a solution in which a short section of the entry side of the weft picking channel is conicaily narrowing and is followed by a parallel-shaped section throughout the whole (remaining) length of the weft picking channel.
• This modification of the profile dents is adapted to the main picking machanism consisting of two main jets situated over each other and permitting the weft mixing or the colour change. Due to the variability of the entry axis of the picking weft, the entry side of the weft picking channel is extended so as to form a funnel for drawing in the wefts into the parallel operating section.
• a still another solution of the weft picking channel of a pneumatic weaving machine has been disclosed in the CS AO No. 219 512.
• the upper and the back wall of the weft picking channel consist of profile dents with upper nose-shaped protrusions.
• the lower part of the weft picking channel wall consists of an auxiliary body with auxiliary jets, and the back surface of the auxiliary body carries warp threads of the lower shed strand. Said back surface is saw-like shaped, and the mouths of the auxiliary jets are situated in the front faces of the saw-like protrusions.
• the upper side of the weft picking channel, consisting of the protrusions of the reed dents, is parallel to the direction of the pick weft.
• the upper side of the body comprising the auxiliary jets can have various shapes in the sections of the saw-like protrusions.
• said body with auxiliary jets is by means of an excentric mechanism arranged adjustably with respect to the protrusions of the reed dents so as to partly close the weft picking channel at the pick moment.
• the drawback of this solution consists in the switching over of the lower shed which increases the risk, in particular in the selvedge sections, of the warp thread of the upper shed getting caught into the picking recess of the glider.
• the yarn remains in the weft picking channel and thus unfavourably effects the picking medium, especially with thick yarns.
• the yarn is explosed not only to the effect of air pressure but also to increased abrasive wear on the channel bottom
• a better beat-up of the weft into the binding point of the fabric in process of manufacture is aimed at by the reed being arranged in such a manner that the dents and the protrusions out of which the weft picking channel is made have in the temple area flat dents and then the profile ones, or the profile dents regularly alternating with the flat ones independently of the position of the auxiliary jets.
• This solution requires a design modification of a sliding inserting jet and of a suction jet that is difficult to realize in case of the colour change.
• the auxiliary jets are situated at a long distance from the weft picking channel with the ensuing low efficiency of the pick system and increased picking medium consumption.
• the last known embodiment disclosed in the US patent No. 5,323,814, has in the area of the weft picking channel the sides slanted in such a manner as to direct the air stream towards the centre of the weft passage.
• the slanting is carried out in at least a part of the thickness of each dent, while the shape of the weft picking channel remains constant and parallel with the picked weft.
• the advantage of the embodiment of the open weft picking channel according to the invention consists in the possibility substantially to increase the dynamic pressure of the picking medium at the expected motion path of the weft without increasing the picking medium pressure in the auxiliary jets.
• more than one dent following in the direction of the weft pick after the auxiliary jet has the lower outline of the weft picking channel below the level of the outlet aperture of the auxiliary jet, thus ensuring a better air stream passage into the operating section of the weftpicking channel and improving the air streaming in the operating section of the weft picking channel while the weft is carried by the shed.
• the lower outline of the weft picking channel of the profile dents after the auxiliary jet is narrowing in the direction of the weft pick in the direction towards the constant profile of the weft picking channel, thus still more improving the air streaming coming from the auxiliary jets and passing through the weft picking channel.
• the lower edges of the profile dents are slanted into one slanting plane converging in the direction of the constant profile. This slanting of the lower edges provides for undisturbed streaming of the picking medium through the weft picking channel.
• the constant profile dents occupy in each case at least one third of the distance between two auxiliary jets
• the advantage of the open weft picking channel according to the invention consists in the reduced consumption of the picking medium as well as in increased reliability and speed of the weaving process. Directing the auxiliary jets more into the direction of the weft pick, defined by the shape of the weft picking channel and the positioning of the auxiliary jets, also increases the uniformity of the picking medium streaming. Another effect consists in the reduction of the batten weight and, consequently, of its inertia forces.
• Figs. 1 and 2 show in cross section two embodiments of a beat-up reed with various fixing in the batten of a weaving machine, with alternately attached auxiliary jets.
• Fig. 3 is a front view of the beat-up reed with an open weft picking channel according to the invention, and Fig. 4, 5, 6 and 7 show profile dents with various profile creating a proportionally variable weft picking channel.
• a beat-up reed 1 with profile dents 2 is by means of a wedge 3 fixed in a wedge-shaped groove 4 of a batten 5.
• bodies 7 Adjustably fixed to the batten 5 from the side of the fabric 6 being produced are bodies 7 having adjustably fixed thereon auxiliary jets 8. Inserted between the dents 2 are warp threads ? passing through the guide eyes of healds 10.
• the lower frame of the reed is a shaped one. Through the holes in its side wall there are inserted and with a screw 11 fastened the cylindrical bodies 7 with the auxiliary jets 8.
• the profile dents 2 are equipped with a protrusion 1_2 with a recess creating the profile of a weft picking channel 13.
• the size of the recesses of the profile dents 2 changes from one profile dent to the other. thus modifying the resulting outline of the weft picking channel 13 along the length of the beat-up reed 1.
• each dent 2 By the recess depth of each dent 2 is defined the width of the weft picking channel which is constant throughout, while the back walls of the recess, forming the beat-up edge of the reed 1, lie in the same plane.
• the upper edge of the recess of each dent 2 lies in the reed 1 in the same height.
• the lower edges of the dents 2 creating the lower outline of the weft picking channel 13 lie in front of each auxiliary jet 8 in the same height and form in cooperation with the back and the upper edge the constant profile of the weft picking channel 13.
• the length of this constant profile of the weft picking channel 13 between two adjacent auxiliary jets 8 makes at least one third of the distance between the adjacent auxiliary jets 8.
• the first dents 21 have no lower outline edge, the back beat-up edge being continuous up to the lower edge of the first dent 21 This provides for a room in the reed 1 to situate the auxiliary jet 8 into the width of the weft picking channel 13.
• the whole outline of the auxiliary jets 8 lies under the lower outline of the constant profile of the welt picking channel 13.
• the lower edge of the second profile dent 22 forms the outline of the weft picking channel 13 below the level of an outlet aperture 14 of the auxiliary jet 8.
• Each following third dent 23 has its lower edge positioned somewhat higher until, after a length, these lower edges reach the lower outline of the weft picking channel 3 formed by the fourth dents 24 with a constant profile.
• the lower edges of the third dents 23 can be slanted in a slanting plane converging from the second profile dent 22 towards the constant profile of the weft picking channel 13.
• the weft 16 is inserted by a not represented main pick jet into the weft picking channel 13 whose varying cross section is made by the profile dents 21, 22, 23, and 24. After its insertion into the weft picking channel 1_3, they create a stream of the picking medium of the timed auxiliary jet 8 acting in particular on the front of the weft 16 being inserted, and lead it in the upper inner corner of the weft picking channel 13.
• the batten 5 swinging in a not represented weaving machine carries both the reed 1 and the auxiliary jets 8.
• the insertion of the weft 16 through the weft picking channel 13 takes place at a period when the healds 10 of a not represented harness mechanism shape the warp threads 9 into an open shed 17. Due to the fact that the outlet apertures of the auxiliary jets 14 are arranged in the width of the weft picking channel 13, the arrangement of the profile dents 2J .
• the weft 16 in process of insertion is moved by the swinging motion of the batten 5 towards a binding point 18 representing the front of the fabric being produced.
• the back beat-up edge of the profile reed 1 beats the weft 16 into the binding point 18 whereupon it is covered by the warp threads 9 led in the eyes of the healds 10 fixed in not represented heald shafts.
• the dent 21 having assigned thereto auxiliary jets 8 in the profile reed 1, provide then for sufficient space for moving the warp thread 9 introduced between them during the changing of the shed 17.

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• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Looms (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=5465405

Family Applications (1)

Country Status (2)

Citations (4)

• 1995
  • 1995-10-16 CZ CZ952690A patent/CZ284902B6/cs not_active IP Right Cessation
• 1996
  • 1996-10-11 WO PCT/CZ1996/000020 patent/WO1997014833A1/en not_active Ceased

Patent Citations (4)

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