trick 22 houses a needle 23 the upper end of which terminates in a latch 23a and a jack 24 said jack 24 is mounted slidingly and rockingly in the trick 22 rocking takes place around its elbow 24a and is controlled by a selection transmission jack 25 which rocks around a rounded surface 25a arranged at its lower end and which bears against the needle bed 20 said jack 25 has two butts 25b and 25c butt 25b situated towards the lower end of the jack 25 is arranged to engage periodically a fixed cam 26 the purpose of which will be explained hereinafter this fixed cam 26 has a preparation ramp 26 39 a cocking ramp 26a and an uncocking ramp 26c the upper butt 25c cooperates with the selector 27 constituted by a resilient strip normally held a certain distance below the armatures of an electromagnet 28 identical to the electromagnets 18 of the first embodiment although only one selector 27 has been shown in fig4 in reality each feed will comprise several stacked selectors 27a 27b 27c as shown in fig3 each selector being associated with a respective electromagnet 28a 28b 28c consequently the upper butts 25c of the different selection jacks 25 will be situated at respective levels corresponding to the levels of the selectors with which they are associated the selection transmission jack 25 also has a laterally extending bent arm 25d which when the jack is caused to rotate by the needle bed 20 describes a path along which there is a fixed levelling cam 29 for causing the selection transmission jack 25 to rock towards the right with respect to the position shown in fig3 as will be seen in fig4.