Device for joining thread ends

3,345,809

Oct. 10,1967

H. GEMEINHARDT ETAL

DEVICE FOR JOINING THREAD ENDS

Filed July 28, 1966

Sheets-Sheet 1

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INVENTORS:

HERMANN GEMEINHARDT RICHARD MONZER

BY· ^&lt;==it‘ ATT'YS

3,345,809

Oct. 10,1967

Filed July 28, 1966

H. GEMEINHARDT ETAL

DEVICE FOR JOINING THREAD ENDS

Sheets-Sheet 2

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INVENTORS:

HERMANN GEMEINHARDT RICHARD MClNZER

<img file="US3345809A_D0003.tif" />

ATT'YS

3,345,809

Patented Oct. 10, 1967

United States Patent Office

3,345,809

DEVICE FOR JOINING THREAD ENDS Hermann Gemeinhardt, Elsenfeld, and Richard Miinzner,

Obernburg, Germany, assignors to Vereinigte GlanzstoS-Fabriken AG., Wuppertal-Elberfeld, Germany

Filed July 28,1966, Ser. No. 568,654

Claims priority, application Germany, July 29, 1965, V 17,869; Sept. 17, 1965, V 29,347

Claims. (Cl. 57—22)

The present invention relates to a device for the knotless joining of thread ends, said device being operated with compressed gas and including a resonance surface opposite a gas nozzle.

During the manufacturing and processing of threads and yarns it is unavoidable that the length of the threads and yarns will vary so that either considerable scrap results or the thread ends must be joined by knots. The presence of knots is not desirable, however, because very often they cannot appear in the end product. A forty meter mountain rope with a knot, for example, likely cannot be sold and is substantially worthless. As a further example, flat textile goods in woven form can only have knots on the reverse side.

Attempts to join thread ends by bonding has proved unsuccessful largely because such joints introduce other problems. Wide, hard spots result which create problems during processing, for example, during threading, in the same manner as knots. Such wide, hard spots also do not take a twist and do not shrink.

Devices are presently known for the manufacture of so-called tangled yarns. These devices consist mainly of a compressed gas nozzle and a resonance surface opposite the nozzle mouth. These devices have also been used to connect yarn ends. The two yarn ends are laid side by side in a thread guide and held under a slight preselected tension. Air is then blown onto the threads for a short time to produce the connection. However, since these devices were primarily designed in the manufacture of tangled yarns, they are not adequately equipped for the joining of yarn ends. Consequently, the production of such joints was time consuming and inconvenient and often not possible at all because the devices are solidly mounted and are difficult to work on. Likewise, these machines lacked a positive clamping of the thread ends which is required to assure a satisfactory joint.

It is an object of the present invention to provide a device for joining thread ends which avoids the difficulties outlined above.

It is another object of the invention to provide a device for joining thread ends which can be easily transported and which operates in a dependable manner.

Other objects will become known to those skilled in the art from the following detailed description of the invention.

In general, the subject invention involves the discovery of a device which can be used to join thread ends by twisting with the help of a gas stream. The success of the device flowed from the discovery of an arrangement wherein a piston operating against a spring is arranged between a gas pressure valve and a generally known air nozzle, which nozzle is located opposite a resonance surface. The piston lies within a cylinder which is preferably set up parallel to the air nozzle axis. The distance between the air nozzle and the resonance surface is adjustable because both parts can be shifted in either direction along a common axis. The piston acts upon clamping means which include two U-shaped enclosures or covers which limit the air zone. The clamping device features clamping points lined by an elastic material at the level of notched guides of lateral covering sheets for the air zone, which guides support the two thread ends. The dimen2 sions of the piston and spring are selected in such a way that first of all the clamping becomes effective and then the effective air pressure builds up. Due to the lining with the elastic material, the secure holding of the thread ends 5 is guaranteed.

The invention can best be understood by reference to the attached drawing wherein:

FIGURE 1 is a sectional view of a device of the present invention which is in the form of a pistol; and ₁₀ FIGURE 2 is a perspective view of the device with some parts cut away to show underlying mechanisms.

In the figures, compressed gas line 2 is shown screwed into insert 33 in handle or base portion of device 1. Valve 3 which operates against spring 4 blocks air channel 6 15 which leads from gas line 2 to air nozzle 17. Air channel 6 is opened by pressing against trigger or button 5. Piston 7 acting against spring 8 is mounted in cylinder 34 below air nozzle 17, said piston acting upon shaft 10 via piston rod 9 in the manner described more fully below.

In the upper portion of the device, nozzle 17 and resonance surface 18 are mounted in two coaxial bores in the housing of the device. Cut-out or relief 31 lies between the nozzle and the resonance surface. The nozzle and the resonance surface are held in place by set screws 23 and 25 25. The nozzle itself consists of a cylindrical body which is slidably mounted within one of said bores. Bore 20 of the nozzle and the extended opening 19 into said bore permits the entry of air from channel 6 at every longitudinal position at which the nozzle might be placed for 30 adjustment purposes. The nozzle opening or muzzle is identified by numeral 21. The resonance surface 18 is of well known construction and is mounted on cylindrical insert 24 which, in turn, is movably mounted within device 1. The insert and the resonance surface can be fixed 35 in place by means of set screw 25.

Covers or side panels 28 which can be constructed of sheet metal are mounted at both sides of cut-out or relief 31. These covers include scores or notched guides 32 which serve as support for the thread ends to be joined.

Two side panels 11 and 12 are connected by means of upper plates or panels 29 and 30 to form U-shaped enclosures or covers. These covers are rotatably mounted on shafts 13 and 14. A pin 15 can be inserted into both side panels 12 of one cover 12-30 which pins gear into 45 a corresponding slot in the panel parts 11 of the second cover or enclosure 11-29 to provide a coacting movement between the two parts. The two covers 11-29 and 12-30 are adjusted so that when swung together, scores or guide notches 32 line up with the thread contact points of panels 50 11 and 12, preferably in the center of cut-out or relief

31. The coaction between the two covers 11-29 and 12-30 . can be produced in another manner such as through the use of a cam or meshing gears.

The two panels 11 are extended to shaft 10 which is 55 mounted in corresponding bores of the side panels 11. In the design shown in the drawing, side panels 11 and 12 include semicircular openings at the height of the notched guides 32. Inserts 16 consisting of rubber or similar material are placed in said semicircular cut-outs. Inserts 16 60 clamp to thread ends in such a manner that a line through the base of the two notched guides 32 runs through the center of the contact surface of the insert.

As was pointed out above, the coacting movement between the covers to form one unit may be accomplished 65 by any one of many methods. Likewise, the principle of the invention remains the same regardless of whether side panels 11 or side panels 12 are engaged with shaft 10. If shaft 10 engages side panels 12 the operating direction of piston 7 is reversed.

In operation, after nozzle 17 and resonance surface 18 have been adjusted in a known manner such that the introduction of the compressed air has the desired effect

3,345,809 ³ of twisting and joining the thread ends, the device is ready for operation. When trigger or button 5 is pressed, the passage for the gas from line 2 to nozzle 20 is opened. Simultaneously, piston 7 is acted upon by the compressed air and is moved in cylinder 34 against the force of spring 8. The movement of piston 7 causes covers 11-29 and 12-30 to move together. This assures a positive clamping of the thread ends and also closes off the blow zone to the outside.

It has been shown that a slight delay between the start of movement of piston 7 and the build-up of the required pressure in the air nozzle is sufficient to clamp the threads securely before they are hit by the air coming from opening 21, This results if the piston area and the spring force are properly balanced prior to the operation of the device. It is required that the clamping action of covers 11-29 and 12-30 be initiated slightly before the pressure build-up is completed if the device is to operate in a dependable manner.

It has been found to be necessary to dimension piston 7 or rather cylinder 34 and spring 8 so that a secure clamping is already obtained at a gas pressure of from %0 ίθ , or preferably Vs to 'A of the working pressure that builds up in nozzzle chamber 20. In addition, the cross-section of valve 3 and passage 6 should allow a full function of the nozzle but, on the other hand, be tight enough to prevent a rapid pressure build-up behind the valve. The smaller the necessary pressure for the actuation of the clamping device in relation to the working pressure of the nozzle, the less critical is the cross-section of valve 3 and passage 6. The working pressure of the blow nozzle preferably lies between 1.5 and 10, and more preferably between 2.5 and 6 kg./cm.² above atmospheric pressure.

The present device can be used with success where thread material of one kind is wound into another kind, for instance, for spool and twine machines, the manufacture of weft bobbins, etc., and also for the processing of thread on weaving and knitting machines. The device can be mounted in place or can be hand-carried. A handcarried device of the present invention is of advantage for spool and twine machines. In other cases such as in the manufacture of weft bobbins, etc., it may be of advantage to install a device according to the present invention as a fixed part of the machine. A device according to this invention can especially be used to advantage where stationary knot devices or automatic knot tying devices were previously in use. A thread joint as produced by a device according to this invention has the same characteristics as the thread material itself and does not require special attention in processing. It is now possible to produce thread of any length.

A stationary device according to this invention can be used for an automated joinings of threads. The ends that have to be joined can, for example, be held by claws as known on the automatic knot tying machines and be laid into the device according to this invention. A corresponding electrical circuit which, for example, can be actuated by the claws can be initiated by a limit switch.

Joints produced by a device according to this inven4 tion feature the same tensile strength as the yarn itself. The thicker thread portion is hardly noticeable and runs through all devices like thread guides, knitting needle eyes, etc., without any problems. Of special importance is 5 the fact that the joints are not noticeable in texturing processing such as upsetting, etc., and cannot be noticed after a dyeing process.

Valve 3 shown in the drawing can be actuated by a foot pedal if a corresponding lever or pujl connection IQ is used. This can be of advantage when a rigidly mounted device according to this invention is used, or this can be accomplished by the actuation of a limit switch by the holding device when an automatic holding device for the thread ends is employed. The switch contact duration can 15 be made adjustable by the use of a time relay. This can control the duration of the device and the following release of the connected thread. An automatic holding device like the one already known for the automatic knot tying machines can also be employed.