Patent GB-854392-A (GB)
Title: Improvements in and relating to hydraulic drive mechanisms for the thread guide rails of flat coulier knitting machines
IPC: D04B15/64
Filed: 1959-01-16
Abstract: 854,392. Knitting-machines. VERWALTUNGSGESELLSCHAFT DER WERKZEUGMASCHINENFABRIK OERLIKON. Jan. 16, 1959 [Jan. 16, 1958], No. 1615/59. Class 74 (2). Each yarn carrier rod 7 is reciprocated by a piston 10, the ends of which co-operate with a pair of alternately- and single-acting cylinders 11; and the cylinders are independently longitudinally adjustable, the stroke of the carrier rod being limited by the piston rod heads abutting against stops 12<SP>1</SP> in the cylinders. Each cylinder 11 is formed in a block 13 in which is also formed a servomotor cylinder 15 co-operating with a stationary piston 18; and, under the control of a slide valve 19, the whole block slides along the servomotor piston rod 14 between predetermined positions in which it is locked hydraulically. A spring 28 urges the valve 19 into its outer position in which pressure fluid is admitted, via duct 24, to the outer end of the servomotor cylinder, the block 13 then moving outwardly until a slide 30 abuts against a stop 45 and is slid inwardly, taking with it the valve 19 to its central locking position. This determines the outermost rest position of the block, corresponding to inactivity of the yarn guide. When a switch 37 is closed, an electromagnet 34 on each of a pair of co-operating blocks is energized, and each armature is projected to force inwardly the slide 30 and, with it, the valve 19, into its innermost position in which working fluid is admitted to the other end of the cylinder 15. Consequently, the block moves inwardly until a step 31 or 32 abuts against a stop 31a or 32a, allowing the spring 28 to return valve 19 to the locking position. The stops 31a, 32a are carried on rings 38, 42, adjustable inwardly and outwardly along the machine by pairs of right-hand and left-hand screw threads on lead screws 39, 43; and the stops may be removed or rendered inactive by folding them down. The left-hand block may then be moved towards the right-hand block until an abutment 33 touches a stop 33a on the opposite block; this may be used in margin reinforcing. As the carrier rod nears the end of its stroke, a spigot 100 at the ingoing end of the piston rod 10 enters a corresponding bore 102 in the cylinder head 12 and blocks the direct escape of fluid from a space 103 at the inner end of the idle cylinder 11; and thereafter that fluid can escape only by way of an adjustable valve 109, recesses 104<SP>1</SP> or grooves 106<SP>1</SP> machined in the spigot, or a predetermined clearance between the spigot and the bore 102. On the next stroke, when that cylinder becomes the active one, working fluid can pass freely, via a ball valve 108, into the space 103. The two cylinders 11 of a pair are supplied alternately with working fluid under control of a slide valve 55 moved endwise against the action of a spring 56, by one of cams 57, on a rotating shaft 58. Chosen thread guides may be inactivated by manually operated means which slides discs along the shaft 58 to bring flanges on the discs into the paths of rollers on the valves, which then ride on these flanges with the valves in their locking positions.