GB345399A - Improvements in driving motions for dobbies of looms for weaving - Google Patents

Abstract

345,399. Loom dobbies. BLACKBURN LOOM & WEAVING MACHINERY MAKING CO., Ltd. and WATSON, R., Phoenix Iron Works, Blackburn. Jan. 22, 1930, No. 2173. [Class 142 (i).] In dobbies of the Keighley type, the top and bottom draw knives are operated by two separate pivotally mounted levers, so that an independent movement is given to each of the draw knives of the dobby, to enable a dwell period to be imparted to the healds after each crossing period, and also a further movement to be given thereto for the release and the take up of the hooks. The top knife C<1> is connected by a rod d<3> to the top of a lever D<1> pivotally mounted at d<1>, and the bottom knife C2 is similarly connected by a rod d4 to the bottom of a lever D<2> pivotally mounted at d<2>. The knives C<1>, C<2> are connected at the other side of the loom to duplicate levers mounted on the studs d<1>, d2. Antifriction bowls d are provided at the top and bottom of the levers D<1>, D2, the top and bottom bowl respectively of each lever contacting with top and bottom cams B<1>, B<2>, which are mounted on a vertical shaft A<1> driven by bevel gears a, a<1> and spur gears a<2>, a<3> from the main driving shaft A<2>. The cams are mounted on the rotating shaft with the maximum throw of one cam opposite the maximum throw of the other, as shown in Fig. 3, the top cam B<1> having a convex surface bb to give the additional movement to the draw knives for the release of the hooks, whilst the bottom cam is formed with a concave surface b<3>, b3 to allow a synchronized movement of the pivoted levers.