Thread feed device
AssigneeSobrevin Societe de brevets industriels-Etablissement
InventorErmete Riva
Life of this patent
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Abstract
A thread feed device having a storage body to which the thread is fed at one end in circumferential direction, and from which the thread is drawn off in axial direction (overhead), and with which there is associated a scanning device. A signal of the scanning device controls the thread winding speed. A swing arm bears a sensor part of the scanning device, said sensor part cooperating without contact with a stationary sensor part. In all positions of the swing arm, signals received from the stationary sensor part, starting from the depositing of the first thread turns on the swing arm, controls a reduction in the thread-winding speed, which speed decreases to a minimum value in a manner, corresponding to the increasing coverage of the length of the swing arm by turns of thread.
Claims33
A thread-delivery device having a storage body on which thread turns of a thread fed at one end in circumferential direction are deposited and from which the thread is withdrawn in axial direction (overhead), the storage body having on outer surface in the shape of a drum upon which turns of the thread are displaced during a feeding of the thread, the device comprising
- a scanning device adjacent the storage body for scanning the thread turns as the thread turns are displaced from one end of the drum to the other;
- wherein said scanning device comprises a swing arm which extends over a thread storage region of the storage body, a stationary sensor part positioned in fixed relation to the storage body, and a movable sensor part carried by the swing arm, the swing arm being swingable towards and away from the storage body;
- the storage body has a feed-side end region, the swing arm is mounted in the thread feed-side end region of the storage body, the swing arm has a free end extending in a direction of displacement of the thread turns, there being in all positions of swing of the swing arm an inclined attitude with respect to the outer surface of the storage body, the swing arm being covered with wound turns of the thread;
- the thread delivery device further comprises force means for exerting a restoring force against the swing arm, the position of swing being determined against the restoring force by a deposit of a first of the wound thread turns to control the position of the movable sensor part;
- means for winding thread on said storage body, and means coupled to said winding means for varying a winding speed;
- said moveable sensor part cooperates with the stationary sensor part to provide at the stationary sensor part a sensor signal indicative of the position of the moveable sensor part, with speed varying means being responsive to said sensor signal to attain a reduction in a thread winding speed corresponding to an increasing covering of the length of the swing arm with thread turns;
- the moveable sensor part comprises a magnet disposed on the free end of the wing arm, and the stationary sensor part comprises a magnetic field detection element disposed outside the storage body;
- and
- the thread winding speed is varied by said varying means corresponding to a change in a field strength at the magnetic field detection element which is caused by a distancing of the magnet from the magnetic field detection element.
A thread-delivery device having a storage body on which thread turns of a thread fed at one end in circumferential direction are deposited and from which the thread is withdrawn in axial direction, (overhead), the storage body having an outer surface in the shape of a drum upon which turns of the thread are displaced during a feeding of the thread, the device comprising
- a scanning device adjacent the storage body for scanning the thread turns as the thread turns are displaced from one end of the drum to the other;
- wherein said scanning device comprises a swing arm which extends over a thread storage region of the storage body, a stationary sensor part positioned in fixed relation to the storage body, a light source disposed on the stationary part and providing a light beam, and a movable sensor part carried by the swing arm, the swing arm being swingable towards and away from the storage body;
- the storage body has a feed-side end region, the swing arm is mounted in the thread feed-side end region of he storage body, the swing arm has a free end extending in a direction of displacement of the thread turns, there being in all positions of swing of the swing arm an inclined attitude with respect to the outer surface of the storage body, the swing arm being covered with wound turns of the thread;
- the thread delivery device further comprises force means for exerting a restoring force against the swing arm, the position of swing being determined against the restoring force by a deposit of a first of the wound thread turns to control the position of the movable sensor part;
- means for winding thread on said storage body, and mans coupled to said winding means for varying a winding speed;
- said moveable sensor part cooperates with the stationary sensor part to provide at the stationary sensor part a sensor signal indicative of the position of the moveable sensor part, said speed varying means being responsive to said sensor signal to attain a reduction in a thread winding speed corresponding to an increasing covering of the length of the swing arm with thread turns;
- the moveable sensor part comprises a reflection area arranged on the free end of the swing arm to serve as a mirror for deflecting the light beam, and the stationary sensor part comprises a light beam detector arranged outside the storage body, the thread winding speed being varied corresponding to a shift in location of a light beam impingement point on the light beam detector caused by a swing arm movement.
Dependencies are inferred from the claim text.