Method and device for pneumatic threading in a double hollow pin spindle of a doubling frame

A method for pneumatically threading in a path, a double twisting doubling frame having a double hollow pin twisting spindle for producing a multi-ply yarn, wherein the spindle has a first and a second thread feeding bobbin coaxially disposed and positioned on respective hollow pins in the head of the spindle, wherein the bobbins engage their respective hollow pins by having the thread unwound from the bobbins directly enter their respective hollow pins, and wherein the method comprises:

• a) removing an initial length of thread from the first bobbin positioned on its respective hollow pin in the head of the spindle for insertion into the second bobbin hollow pin;
• b) removing an initial length of thread from the second bobbin positioned on its respective pin for holding with said length of thread from the first bobbin, while the second bobbin is inserted into the head of the spindle;
• c) placing said held lengths of thread on the hollow at the end of the second bobbin hollow pin;
• d) moving a compressed air means towards the hollow at the end of the second bobbin hollow pin;
• e) displacing the second bobbin hollow pin along its longitudinal axis by said compressed air means thereby laterally displacing a braking means for controlling the thread tension away from the thread path, wherein said braking means is located in the thread path along the longitudinal axis of the first and second bobbin hollow pins and therebetween, so that the thread may be directed in the thread path and into the hollow of the first bobbin hollow pin;
• and
• f) injecting compressed air from said compressed air means for transporting the lengths of thread from the first and the second bobbins through the hollows of the first and the second bobbin hollow pins and advancing said lengths of thread into the head of the spindle for starting the formation of the multi-ply yarn.