GB1453898A - Sewing machine - Google Patents

Abstract

1453898 Cams SINGER CO 28 Jan 1974 [26 April 1973] 03944/74 Heading F2K [Also in Division D1] Mechanism in a sewing machine for moving followers 51, 52, 64, 65 to engage selected cams of a stack 20 comrises means operated by an unloading dial 90 to swing the followers away from the cams and means 110, Fig. 1 or 210, Fig. 5, to move the followers along the cam stack. The stack comprises pattern feed and button holing cams, the top cams (25, Fig. 2, not shown) comprising a removable invertable set. Upper and lower feed cam followers 52, 53 are rotatably and slidably mounted on a support post 47; upper and lower pattern cam followers 64, 65 are similarly mounted on a post 48. Each follower 51, 52 64, 65 has a boss as at 53 slotted as at 54 to each receive a respective follower positioning pin presented by the cam selection module 110. Feed followers 51, 52 present bifurcated ends as at 56 embracing a feed transfer bar 50 rockable about post 47 and connected to feed adjusting means not described. Follower 51 comprises two parts, the part 59 being adjustably secured to the remainder by a screw 60. Pattern followers 64, 65 abut a pattern transfer plate 78 pivoted on rod 73 and which is adjustably contacted by a driving arm 79 connected to the needle gate; adjustment of 79 along the transfer plate varies the needle bight. A bracket 63 is movable to adjust the pattern transfer plate 68 and vary the needle field. The unloading dial 90 has a cam track 89 engaged by a roller follower on an arm 86 of a bracket 85 rotatable on post 48. Rotation of the dial swings bracket 85 to move feed bar 50 and followers 51, 52 away from the cams, a lug 94 on bracket 85 simultaneously rotating a lever 97 to swing pattern transfer plate 78 and pattern followers 68, 65 from the cams. In the embodiment of Fig. 1 the cam selection module comprises a plate 10 having a slide plate 136 and follower adjustment pins 143, 160, 162 and 201 all movable vertically on plate 110, and a horizontally slidable selector member having a rack 111 engaging gears 104 operated by a selector dial 103. Horizontal movement of the selector causes, through T lever 126, vertical movement of the slide plate which, at the upper margin of its movement abuts pins 161, 162 to raise them aginst spring 178 to move cam followers 64, 51 and at the lower margin of its movement abuts lever 194 to similarly actuate pin 201 and its cam follower 52. Pin 143, for follower 65, is mounted on the slide plate and supports a pawl 154 which engages serrations 148 on a plate 147 adjustably mounted in plate 110. An indicator 117 indicates the mode at which the selector is set. In a second embodiment of the cam selection module (Fig. 5) the selector member 216 is horizontally slidable on a plate 215. A bell crank lever 230 is connected by a link 236 to the lower pattern cam follower positioning pin 237 and has a pin 32 engaging a slot 233 in the selector member. A crooked lever 249 is pivoted at 250 to plate 215 and pivots at 253 an arm 252 engaging a slot in a pin 248 on bell crank 230. Lever 249 and arm 252 are urged together by a spring 254 to bias the lower feed follower positioning pin 264 upwards in its slot 263. The other follower positioning pins 293 and 305 are connected by respective linkages 292 and 298, 300, 304 to a three armed lever 281 presenting a pin 285 which may co-operate with a slot 288, 289 in a lever 276 pivoted at 277 to the selector member 216. As the latter is moved rightwards from its Fig. 5 position pin 232 is operated to rotate bell crank lever 230 clockwise, follower pin 238 rising while a pawl 240 thereon successively engages serrations 269, &c. Abutment face 259 on lever 249 also rises to follow the rotating bell crank lever and raise the follower positioning pin 264 in its slot 263. When the extension 275 on bell crank 230 meets and lifts lever 276 on selector 216 (Fig. 6, not shown) slot 288, 289 embraces pin 285. Further rightward movement of selector 216 then rotates three armed lever 281 to raise follower positioning pins 293 and 305 to position the followers at the required cams.