GB859924A - Pressure arm particularly for devices for drawing textile fibres - Google Patents

Abstract

859,924. Drafting apparatus. SOC. ALSACIENNE DE CONSTRUCTIONS MECANIQUES. July 15 1958 [July 28,1957], No.22654/58. Class 120(2). So that the top rollers can be positioned where desired, the arm 1 carrying them has a slideway along which roller-supporting members 14 may be moved and has positioning means co-operating with complimentary means on the members, the latter having resilient means serving both to lock the members in desired positions, and also to press the rollers against the lower rollers or other members with which they co-operate in the working position. The slideway is provided by forming the arm as a channel-member having teeth 17, 19 co-operating with teeth 16, 18 on the members 14 to form the positioning-means. Each member 14 comprises outer and inner parts 14, 15 Fig. 2: the latter acts as a piston terminating in a resilient clamp 15c holding the roller spindle, and has lugs 15b Fig. 2, which protrude through the walls of the outer part 14 into grooves 1a in the walls of the arm. The outer part 14 carries a block having the teeth 16. When it is desired to adjust the position of a roller, the block is pulled downwardly against the action of a spring 23 between the two parts of the member 14 to free the teeth and permit the member to be moved: it is then released so that the spring forces down the piston 15 until the lugs 15b engage the lower faces of the grooves 1a whereupon the spring forces the outer part upwardly for the teeth 16, 17 to engage. When the arm is lowered the rollers engage with their co-operating rollers &c. and the piston is forced upwardly to separate the lugs 15b from the bottom of the grooves 1a and allow the part 14 to descend whereby the teeth 16, 17 are disengaged the teeth 18, 19 however remaining in contact. To allow for a fine adjustment of the members 14, the teeth 19 are provided only on one side of the arm, and the pistons are offset from the centre of the members 14 by one quarter of the pitch of the teeth so that according to which way round the member 14 is inserted in the slideway the position of the roller may be adjusted by half the pitch of a tooth. The arm is mounted on a support 25, adjustment being allowed by teeth 28, 29 engaging the racks: the arm can be locked by rotating a screw passing through an enlarged nut 27 held with its sides in the grooves 1a to force the support against the top of the arm.