GB596398A - Improvements in or relating to positive double-lift open-shed dobbies for looms - Google Patents

Abstract

596,398. Loom dobbies. SOC. ANON. A. SAURER. Feb. 22, 1945, No. 4494. Convention date, Jan. 18, 1944. [Class 142 (i)] In a double-lift open shed dobby having oppositely reciprocating draw knives 7, 8 engaged by hooks 2, 3 controlled by pattern cards 45, each hook has two shoulders for embracing its draw knife, and a third shoulder for abutting a fixed knife 9, 10 to hold the hook against a stop 19, 20 when it is lifted off its draw knife. Easy engagement and disengagement of the hooks and knives is ensured by pressing the hooks against the stops 19, 20 when the draw knives 7, 8 reach the ends of their stroke. This action occurs naturally if one hook (e.g.- 3), is ih engagement with its draw knife, since the baulk lever 4 is then pivoting about the stop (e.g. 19), of the other hook; but if both hooks are clear of the draw knives, an oscillating lever 64, encounters an arm 70 (on a lever 56 carrying the baulk lever 4) and presses the hooks against the stops. The draw knives 7, 8 are coupled to opposite ends of a centrally pivoted lever oscillated by a grooved cam; a similar arrangement reciprocates rockers 38, each carrying a pair of needles 40. The needles read the cards 45 and tilt the rocker so that on its return stroke it strikes one or other of a pair of throwover levers 46, 47, thereby lifting or lowering the associated hook (2 or 3). Each lever 56, Fig. 1, actuates a heald shaft through a link 57, a cam slot 59, and a lever 61; the' ends of the slot are concentric with the pivot of the cam to prevent the forces on the healds from reacting on the dobby.