Stretcher for knitted fabrics

A stretcher for tubular knitted fabric for mounting onto a calender comprising;

• two stretcher arms, positioning rollers, said stretcher arms each carrying said positioning rollers, supplier rollers cooperating with said positioning rollers for pulling up the knitted fabric and making it pass about the stretcher, a pneumatic jack in the median area of said arms for adjusting the spreading of the stretcher, a feeding source for the jack comprising a nozzle external to said jack and positioned opposite a feeding aperture, compressed air being injected inside the jack through the knitted fabric passing about the stretcher, the supplier rollers being driven and operating the spreding of the stretcher whose arms are kept applied onto said supplier rollers by the jack, the size of the supplier rollers being relatively large and provided with grooves having a width corresponding to that of the positioning rollers, the grooves being delimited by two flanges, said jack further comprising a uni-directional locking means whereby the jack may increase the spacing of the arms of the stretcher and any reverse motion is prevented from occurring, said locking means remaining locked as long as there is no pressure other than a predetermined threshold inside the jack.

A stretcher for tubular knitted fabric for mounting onto a calender comprising two stretcher arms, positioning rollers, said stretcher arms each carrying said positioning rollers, driven supplier rollers cooperating with said positioning rollers for pulling up the knitted fabric and making it pass about said stretcher, a jack for connecting both stretcher arms at their median area and for adjustment of the spreading of said stretcher, a feeding source for the jack and means for selectively feeding compressed air to the jack from the feeding source through the knitting passing about the stretcher, to facilitate selected positioning of the positioning rollers, said jack further comprising a uni-directional locking means whereby the jack may increase the spacing of the arms of the stretcher and any reverse motion is prevented from occurring, said locking means remaining locked as long as there is no pressure other than a predetermined threshold inside the jack.