Pneumatic thread tensioning device

In a pneumatic tensioning apparatus that maintains a desired tension in a thread of yarn and the like as said thread is fed from a spool to a knitting or fabric weaving machine, wherein said thread is first fed into and extends through a region, and is then fed into a passageway, an apparatus for controlling thread slack in said region, the apparatus comprising:

• means for providing an airflow in said passageway, wherein said airflow issues from said passageway in a direction that opposes the feed direction of said thread travel into said passageway,
• an air deflector positioned in said region in a manner so as to direct said airflow against said thread after said airflow issues from said passageway, to control slack in said thread as it extends through and travels across said region, and including
• an air channeling member having a first portion that supports said air deflector, and having wall means for defining said region, said wall means further directing said air stream to control thread slack, and
• wherein said channeling member includes a second portion having a means for preventing an increase in the amount of thread slack in said region when said thread is not being fed into said passageway.

A pneumatic tensioning apparatus for maintaining a desired tension in a thread of yarn and the like as said thread is fed from a spool or the like to a knitting or fabric weaving machine, the apparatus comprising:

• a first elongated tubular member having an inner passageway extending the length thereof along an axis, and through which said thread may travel in a particular thread feed direction;
• a second elongated tubular member surrounding said first member so that the inner walls of said second member and the outer walls of said first member define an outer passageway that is coaxial with said axis;
• an air supply means for supplying an airflow into said outer passageway in a direction that is substantially the same as said thread feed direction;
• an orifice for communicating the airflow from said outer passageway into said inner passageway in a manner so that the direction of said airflow is reversed and said airflow flows through said inner passageway in a direction opposite to said feed direction, such opposing flow causing a certain amount of tension in said thread, wherein said reversed airflow travels the length of said inner passageway and issues from an end thereof, and wherein said thread is fed into and extends through a region, and then is fed into said end;
• and
• an air deflector positioned in said region in a manner so as to direct said airflow against said thread after said airflow issues from said end of said passageway, to control slack in said thread as it extends through and travels across said region.