摘要:
In a thread feed device for a textile machine, in particular for an air-jet weaving machine, which comprises a thread storage and feed device between a thread supply device and the picking device of the textile machine and which further comprises an assistant device arranged in the thread path extending from the thread supply device to the thread storage and feed device, the assistant device is provided with a friction drive for the thread. A method of driving a thread comprises the features that, in a friction drive constituting the assistant device, the circumferential speed of the friction drive is controlled such that it is higher or lower than the thread speed in the thread storage and feed device, and that, on the circumference of the friction drive, the thread is fed with a certain amount of slip maintained during the feed process or decelerated.
摘要:
A yarn storage device is provided having a storage drum and a ring surrounding the storage drum. It also has a plurality of yarn stop devices each having a blocking element, which is adapted to be introduced into an annular gap between the storage drum and the ring upon actuation of the yarn stop device. A withdrawing device for the blocking element, which removes the blocking element from the gap after termination of the activation of the yarn stop device, comprises a belt of resilient material.
摘要:
A yarn accumulating and feeding apparatus (1) has a stationary accumulating drum adapted to have a yarn (27) formed into a yarn supply (26) thereon, the magnitude of which is monitored between a minimum and a maximum by means of at least one mechanical probe element (28,28',28",28'",28"") adapted to be displaced by the yarn supply between two positions (I,II) and operatively associated with a switching device located outside of the accumulating drum. The probe element is mounted in the accumulating drum for displacement between one position projecting past the surface of the accumulating drum, and another position extending flush with the accumulating drum surface (15) against the bias of a return force, while a switching device contains a sensor element (20,20',21,21',20",20'") for generating a reaction signal in response to displacement of the probe element but without contacting the probe element.
摘要:
This device has a storage drum (2) onto which an intermediate weft yarn store can be wound by a winding-on member (3) and from which the weft yarn (WY) is withdrawn spiralling around the withdrawal end of the storage drum, at least one yarn stopping device (10/14) being arranged at said withdrawal end and consisting of a stopping element (14) and of actuator means (11) moving said stopping element into and out of the path of the yarn being withdrawn, and an actuator control unit (B) transmitting an actuating signal to said stopping device when a weft yarn length corresponding to the length of the shed (WMS) of woven fabric in the machine has been withdrawn from the storage drum. The actuator control unit (B) is electrically connected to a yarn sensing detector (WD), preferably of optical type and known per se, positioned at the arrival end (AE) of the shed (WMS) for the weft yarn (WY) at a predetermined distance (d) from said arrival end. Thus, the control unit (B) receives an electric signal when the inserted weft yarn (WY) reaches the yarn sensing detector (WD) and in response thereto generates and transmits the actuating signal to the actuator means (11) of said yarn stopping devices for stopping the withdrawal of the weft yarn from the storage drum (2).