and 9 are subsequently energized when stitching must be started again it is suitable that the position of the rod 1 corresponding to the top dead center of the needle bearing bar 15 be such that the first electromagnet 8 is very close to second electromagnet 9 so as to bring about easily a further attraction to each other in case the leading zone of the article need not to be stitched it is sufficient to start the machine with the electromagnets 8 amd 9 in de energized condition causing them to become energized when the stitching must be started in order to control the subsequent energizations and de energizations of electromagnets 8 and 9 a conventional electronic control device can be provided this control device can be timed thus making the operation of the quilting machine automatic the foregoing disclosures relating to the case in which the disengaging means is of electromagnetic type can be easily applied to the case in which the disengaging means is of pneumatic type as is shown in fig4 when the quilting machine has to effect the stitching of the article it is sufficient to keep a preestablished pressure within the chamber of the cylinder 22 so as to block the position of.