Method of adjusting the tensile force ratio between an outer thread and an inner thread when manufacturing cabled industrial yarns, and an apparatus for implementing this method

A hand-held and operated instrument for automatically adjusting the tensile force ratio between axially moving outer and inner threads of cabled yarn during manufacture of such yarn in a cabling machine which includes axially-aligned spindle means and thread guide eye means for forming therebetween a rotating balloon of the axially moving outer thread, means for supplying the inner thread from within the outer thread balloon to a cording point below the thread guide eye means for winding the outer and inner threads about each other for cabling of the threads prior to passing through the thread guide eye means, and means for axially moving the thread guide eye means to vary the height of the thread balloon and thus the tensile force ratio between the outer and inner threads of the cabled yarn including a rack on the thread guide eye means and a rotatable gear wheel in driving engagement with the rack;

• said instrument comprising
• a housing,
• sensing means carried by said housing and adapted to be positioned at a fixed point beyond the thread guide eye means in the path of the moving cabled yarn for measuring the actual tensile force ratio between the outer and inner threads by measuring the difference in length between the outer and inner threads of the cabled yarn and for emitting an electrical output signal corresponding to such measurement,
• evaluation means carried by said housing and operatively connected with said sensing means for receiving and comparing the electrical output signal indicating the measured tensile force ratio with a desired tensile force ratio and for producing an adjusting electrical signal as a function of such comparison, and
• means carried by said housing and comprising a servomotor means for receiving and being operated by the adjusting signal from the evaluation means, and worm gear means driven by said servomotor means and adapted to engage and drive the rotatable gear wheel of the thread guide eye moving means for adjusting the axial position of the thread guide eye means to provide a desirable height of the thread balloon and a desirable outer and inner thread tensile force ratio.

A method for adjusting the tensile force ratio between axially moving outer and inner threads of cabled yarn during manufacture of such yarn in a cabling machine which includes axially-aligned spindle means and axially movable thread guide eye means for forming therebetween a rotating balloon of the axially moving outer thread, and means for supplying the inner thread from within the outer thread balloon to a cording point below the thread guide eye means for winding the outer and inner threads about each other for cabling of the threads prior to passing through the thread guide eye means;

• said method comprising the steps of
• measuring the actual tensile force ratio between the outer and inner threads in the region of the thread guide eye means,
• comparing the measured tensile force ratio with a desired tensile force ratio, and
• adjusting the axial position of the thread guide eye means to provide a desired height of the thread balloon so that the measured tensile force ratio is the same as the desired tensile force ratio.