Patent GB-1460858-A (GB)
Title: Control of the selection of needles in a cir
IPC: D04B15/82
Filed: 1974-03-25
Abstract: 1460858 Knitting machines ERBA MASCHINENBAU AG 25 March 1974 [25 March 1973 10 Sept 1973 31 Dec 1973] 13181/74 Heading D1C Needle selection in flat or circular machines is achieved by electromagnetic or piezoelectric elements acting on pivoted selector members to achieve a small separation between selected and non-selected members whereby a following cam raises selected members to control the associated needles. The control-fields of the pattern and the boundaries of the needle pitch are coincident.  In the embodiment of Figure 1, the members 3 are pivotally mounted horizontally below the needles 2. They may be held in a groove by permanent magnets (IX, see Fig. 3 not shown). An obliquely mounted control electromagnet 5 acting on arms 3d, or a piezoelectric deflector (see Figure 2, not shown), produces a deflection at the tip 3c of the members. The tips thereby pass one side or the other of the tip of a raising cam. The tips 2c of the needle butts are thence presented to the chamfered tip 9a of a deflector 9 at the start of the cam system, (see Figures 4, 7). A similar cam 9" is settable to move needles to or from an inoperative track. The magnet or piezoelectric deflector is controlled by scanning a reflecting/non-reflecting control field of pattern member 13. The member is driven by a gear 14 having a set number of teeth, but whose pitch is chosen according to the machine gauge. In the embodiment of Figure 10, suitable for a flat machine, the selector members are guided in a plastics comb 17, having bulges 17b at the top of the prongs to prevent accidental displacement. The pattern member and magnet are mounted in a single unit, which is pivotable about a centre line to maintain the correct alignment of the obliquely faced magnet poles during to and fro movement of the carriage. The unit is recoupled at the entrance of the cam system, at each reverse of the carriage. The pattern member 13 has a conducting/non-conducting surface sensed by a fine wire. It is driven by engagement of a gear 14 with the stamped teeth of a belt 14b. In the embodiment of Figure 15 pattern member and magnet are again mounted in a single unit. The pattern member is conical and has moulded drive projections along each edge. It has a transparent/opaque field which is illuminated internally and scanned by a head 74. It is driven via a gear 68 engaging a stationary rack 68b. The tips 63b of the selectors 63 have enlarged heads 63a which pass through the field of the obliquely faced magnet. The bent ends 63e of the selector shanks slide along a magnetised steel plate 60e. The needles can be locked in the inoperative position between the shanks and a rail 61. In a further embodiment (see Figures 21, 22 not shown) the selector member is a pivoted butt (82) with an acute-angled tip, pivotally mounted on a pushrod (81) behind each needle. In the embodiment of Figure 28 a moving coil 37 carrying a cam wedge 38 moves in the fields of magnets 34, 35. The cam can selectively depress the butt 30b of a pivoted selector member 30, placing tip 30c in line with a raise cam 31. The cam has a chamfered edge 31c. A similarly pivoted selector may be controlled by an electromagnet or piezoelectric deflector (see Figure 13, not shown). Alternatively (Figure 30, not shown) the coil acts on a selector (32) pivoted horizontally beneath the needle bed. Selected tips are raised by a conical cam (33) thereby raising push rods and needles into the range of lifting cams.