US3677304A - Pneumatic rapier for inserting weft thread into warp sheds - Google Patents

Abstract

A rapier for inserting a weft thread into a warp shed, in which a tube is located in a casing, with one end of the tube being connected to an attachment for generating therein a pressure flow, and the other end projecting from the casing, with its butt being sheared at an acute angle so that the far end of the shear is the closest to the reed, and the near end the closest to the fabric fell.

Description

United States Patent Makachev et al. July 18, 1972 PNEUMATIC RAPIER FOR INSERTING R f rences Cited WEFT THREAD INTO WARP SHEDS UNITED STATES PATENTS 2] Inventors: Nikolai Ivmvkh Mnlmlnv, ulitsa j 3,367,371 2/1968 Mullekom ..1a9/127 py, 12, korpus 1, kv. 27; Alexei 1,721,940 7/1929 Ballou ..l78/18 Nlkolaevich Parshln, Nagomaya ulitsa, 34, korpus 43, kv. 53, both of Moscow, FOREIGN PATENTS OR APPLICATIONS 1,261,463 4/1961 France....; ..139/127 P [22] m June 10, 1970 161,669 5/1963 U.S.S.R. ..l39/ 127 P PP 45,003 Primary Examiner-Henry S..1audon Attorney-Holman & Stern I [30] Foreign Application Priority Data ABSTRACT I 23 i A rapier for inserting a wefl thread into a warp shed, in which y a tube is located in a casing, with one end of the tube being connected to an attachment for generating therein a pressure flow, and the other end projecting from the casing, with its 58 Field s h 1 39/122427 butt being sheared at an acute angle so that the far end of the l 1 shear is the closest to the reed, and the near end the closest to the fabric fell.

2 China, 4 Drawing Figures PATENTED JUL 1 8 I972 IIIIII'IIIIIIII'IIIII ,Zwhm

PNEUMATIC RAPIER FOR INSERTING WEFI THREAD INTO WARP SHEDS BACKGROUND OF THE INVENTION- The present invention relates to devices for inserting a thread into the warp shed, and more specifically to rapiers for use in air jet looms.

Widely known in the art are rapiers for weft thread insertion, comprising a tube located in a casing, with one end of the tube being connected to an attachment for generating therein a pressure flow to deliver the end of the weft thread into the warp shed, while the other end of the tube terminates inside the casing in the form of a cap, or a pipe. The cap or pipe is sheared at its end, thus being sharpened for a more accurate separation of the warp threads forming the shed, and projects beyond the end of the inner tube. The attachment generating the pressure flow is connected to the tube through a chamber and a socket, and the weft thread is introduced into this tube through a sleeve located some distance from the tube end.

In these rapiers, the sharp shear distorts the air flow emerging from the tube, which involves an inaccurate transfer of the end of the weft thread to the receiving (suction) rapier, and correspondingly leads to defects the fabric, i.e., short flights of the weft thread.

In addition, location of the sleeve some distance from the tube end causes air eddying inside the chamber, with part of the air being thrown out into the atmosphere through the sleeve hole, thereby leading to a waste of compressed air, and to a reduced tension of the weft thread. This affects the quality of the weft thread insertion into the shed formed by the warp threads.

SUMMARY OF THE INVENTION The basic object of the invention is to provide a rapier for weft thread insertion into the warp shed, with such a design of the tube, that the compressed air flow in the rapier is, at both the tube inlet and outlet, more organized, not distorted and not eddying, and at the same time ensuring a quality insertion of the weft thread into the warp shed.

With this object in view, the rapier for weft thread insertion into the warp shed, includes a tube in a casing, one end of the.

tube being connected to an attachment generating therein a pressure flow to deliver the end of a weft thread into the warp shed, the free end of the tube, according to the invention, projecting from the casing in the direction of the weft thread movement, and being sheared at an angle so that the far end of the shear is the closest to the reed, while the near end is the closest to the fabric fell.

Such a design completely prevents the distortion and eddying of the air flow at the outlet from the tube, and respectively provides for a more accurate transfer of the weft thread end into the receiving rapier.

The projecting end of the tube is preferably narrowed whereby the air flow is still more concentrated.

In the present rapier the tube end connected to the air pressurizing attachment may be shaped as a restriction, adjoining which restriction are a threaded sleeve provided with a hole for passing the weft thread, and a socket leading from a compressed air source. This arrangement prevents the detrimental effect of air eddying inside the chamber and the sleeve hole on the weft thread, and also eliminates air wastage into the atmosphere, thus improving the weft thread insertion into the warp shed, reducing air consumption, and improving the threading of the weft thread into the threaded sleeve.

To obtain a clearer idea of the invention, the following is a description of a particular exemplary embodiment thereof with reference to the appended drawings, wherein:

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a general front view of the rapier according to the invention;

FIG. 2 is a fragmentary top view, partly in elevation and partly in section of the tube end projecting from the casing;

FIG. 3 is a fragmentary view in section of another embodiment of the projecting tube end; and

FIG. 4 is a fragmentary sectional view showing the tube end connected to the air pressurizing attachment.

DETAILED DESCRIPTION OF THE INVENTION The rapier comprises a casing 1 (FIG. 1) in which a tube 2 is located and a reciprocatory movement is imparted to the rapier (the rapier movement is conventionally shown by arrow A) through a system of hollow levers 3 and 4, with the lever 3 being connected by socket 5 to one end of the tube 2. The lever 4 is mounted on a hollow rotating shaft 6 to which is secured a nipple 7, and connected to the nipple is piping 8 communicating with a source of compressed air (not shown). The movement of the compressed air is conventionally shown by arrow B. A free end 9 (FIG. 2) of the tube 2 projects from the casing l and extends into the shed formed by warp threads 10. A butt ll of the end 9 sheared at an angle, thus being sharpened so that the far end of the shear is the closest to a reed 12, while the near end' thereof is the closest to fell 13 of a fabric 14.

Such a design of the tube precludes the air flow eddying at the outlet therefrom, and respectively provides for a more accurate transfer of the end of a weft thread 15 into the receiving rapier (not shown).

To obtain a more concentrated air flow, the free end 9 of tube 2 narrows as shown in FIG. 3.

Adjoining opposite end 16 (FIG. 4) of the tube 2 are a threaded sleeve 17 with an opening 18 for the weft thread 15, and the socket 5, which embraces the sleeve 17, thus forming a chamber 19. The walls of the end 16 of the tube 2 in the place, where the tube adjoins the sleeve, are constricted. Such a design secures an efi'ect of ejection for a reliable aspiration of the weft thread into the sleeve 17. However, the end 16 of the tube 2 can be straight and in this case, there is also created an ejection effect, but such effect is a weaker one.

To lay the weft thread 15 into the warp shed, the casing l (i.e. the rapier) has reciprocatory movement impartedthereto from the rotating shaft 6 through the hollow levers 3 and 4. At thesame time, clean compressed air is fed through piping, nippie 7, hollow shaft 6, and hollow levers 3 and 4 into the socket 5. The compressed air enters the chamber 19, and then through the end 16 of the tube 2, with an ejection effect being created at such location thereby ensuring air aspiration from the atmosphere into the opening 18 of the sleeve 17. To threadthe weft thread 15, such thread is positioned near the opening 18, and is drawn into the opening of the sleeve 17. By meeting no detrimental air eddies in its path in the chamber 19, the thread 15 passes into the tube 2, in which it is main tained in tension by the air flow, and then, together with the rapier, is forwarded into the warp shed to be transferred into the receiving rapier. The air flow entrains the thread 15, and emerges from the end 9 of the tube 2 in a concentrated form, without eddies or distortions, and as it meets the receiving rapier, it transfers the thread into the suction flow of the receiving rapier; The air flow emerging from the narrowed end 9 of rapier 2 (another version) is still more concentrated. Passing through the rapier, the thread 15 is laid down in the warp :shed, and is then beaten by the reed 12.

What we claim is:

1. A rapier for inserting a weft thread into a warp shed of a loom having a reed, including a casing, a tube located in an extending axially of the casing, said tube having opposite ends, a socket attached to the casing and extending laterally therefrom adjacent one end of the tube, a sleeve embraced by the socket and having a bore for a weft thread, the bore communicating with the interior of the tube at said one end thereof, the other end of the tube projecting from the end of the casing in the direction of wefi thread movement, the butt of said other end of the tube being sheared at an angle and thereby sharpened, with the far end of the shear being closest to the reed and the near end being closest to the fell of the fabric, the tube adjacent said one end thereof having a constriction, and said socket communicating with a source of compressed air for drawing the weft thread into the sleeve bore and thence into the tube for movement into the warp shed.

2. The rapier as claimed in claim 1, wherein the other end of the tube narrows in the direction of the weft thread movement.

Claims (2)

1. A rapier for inserting a weft thread into a warp shed of a loom having a reed, including a casing, a tube located in an extending axially of the casing, said tube having opposite ends, a socket attached to the casing and extending laterally therefrom adjacent one end of the tube, a sleeve embraced by the socket and having a bore for a weft thread, the bore communicating with the interior of the tube at said one end thereof, the other end of the tube projecting from the end of the casing in the direction of weft thread movement, the butt of said other end of the tube being sheared at an angle and thereby sharpened, with the far end of the shear being closest to the reed and the near end being closest to the fell of the fabric, the tube adjacent said one end thereof having a constriction, and said socket communicating with a source of compressed air for drawing the weft thread into the sleeve bore and thence into the tube for movement into the warp shed.

2. The rapier as claimed in claim 1, wherein the other end of the tube narrows in the direction of the weft thread movement.

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