The straight bar frame is, with a number of later improvements and developments, recognisable as a direct descendant of William Lee's hand frame.
Credit for the development of the first acceptable power-driven rotary frame is given to Samuel Wise who, in 1769, replaced the foot pedals with a power-driven rotary shaft whose tappets caught against arms and levers to move the working parts. To increase productivity it was necessary to simplify the knitting action and introduce automatic mechanisms to replace hand-controlled operations. In 1857, Luke Barton replaced hand-controlled loop transfer points used for fashion shaping with a self-acting narrowing mechanism, and in 1861, Paget invented a movable needle bar.
It was, however, William Cotton of Loughborough who transformed the hand-controlled power-driven rotary frame into the high-speed automatic fashioning multi-head straight bar frame. This speeded the transition of knitting from a cottage-based to a mass-production industry. Between 1846 and 1864, he obtained patents which have caused the term 'Cottons Patent or 'Cotton Machine' to become synonymous with that of the straight bar frame.
Cotton invented the vertically moving needle bar, developed the use of screw-controlled fashioning points for automatically widening and narrowing, and placed the driving shaft for the elements towards the base of the machine to reduce vibration.
The replacement in 1953 of the end controls by a central control unit paved the way for the modern automatic straight bar frame with its fully-programmed garment-knitting sequence (Fig. 17.1). Balanced and simplified motions, together with variable draw, have increased knitting speeds, whilst automatic actions have reduced standing time and labour supervision .
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