Patent GB-201298-A (GB)
Title: Buttonhole sewing machine
IPC: D05B3/06
Filed: 1922-05-16
Abstract: 201,298. Fairweather, W., (Singer Manufacturing Co.). May 16, 1922. Button-hole sewing-machines. -The machine described in Specification 183,873 is re-organized so that it will operate to cut the button-hole prior to stitching, and improved means are provided for preventing accidental operation of the clutch for the button-hole cutting- means except when the buttonhole working mechanism is in a safe position. Specification 179,278 is referred to. Button-holes, cutting. Actuation of the starting rod 117, Fig. 1, transmits a single to- and-fro movement to a twoarmed lever 18, 113 in the usual manner. As the arm 18 is depressed, a tooth 122 on a link 123, which is pivoted at 124 to the arm 113, is drawn forward and drops under the influence of a spring 123<1> in front of a shoulder on a lateral arm 126 of the usual controlling lever 106 for the cutter-shaft clutch. The tooth 122 is formed on a plate 127 adjustably fixed to the arm 113. During the return movement of the arm 18, the tooth 122 pushes the arm 126 rearwardly thereby shifting the lever 106 and its latch-plate 105 inwardly to clutch the cutter-shaft 99, Fig. 3. to the continuously-running pulley 109 for one revolution. A cam 143 on the. shaft 99, Fig. 1. lifts a lever 145 pivoted to the machine-standard so that a lateral extension 145<1> thereof lifts the link 123 out of engagement with the arm 126. The usual cam on the hub of the driven disk 102 of the cutter-shaft clutch device restores the bell crank-lever 106, 126 to initial position for arresting the rotation of the cutter-shaft. When the link 123 is lifted the shoulder 158 of a latch lever 156, Fig. 3, as described in Specification 197,463, swings undereneath the link 123 to hold it in ineffective position, and an extension 159 of the lever 156 is positioned in rear of a pin 160 on the arm 126, blocking possible accidental movement of the lever 106, 126, to starting position during sewing. An arm 150 fixed to a rock-shaft 151 engages with a peripheral cam 148 on a rotary control-element 147 on the shaft 36. An arm 153 on the rear end of the shaft 151 is connected by a link 154 to an arm 155 of the latch-lever 156. When the machine is in starting position, the side-throw portion 157 of the cam 148 is in control and the lever 156 is in unlocking position. After the cutter mechanism has operated, the shaft 36 immediately begins to rotate, and the cam 148 swings the arm 150 to the right, Fig. 3, and so positively swings the latch-lever 156 to support the link 123 and lock the cutter-starting lever 126. As the stitch-forming mechanisms arrive at their safe position at the end of the cycle, the offset 157 of the cam 148 acts to unlock the lever 126 to release the link 123. Actuation of feed. The usual rapid-feed and stitching-feed mechanism is employed, the rapidfeed shaft 36, Fig. 5, being connected to the continuously-running shaft 39 by means of the usual endwise-movable rod 44 carrying the clutch-operating fork 46 and a lateral pin 45. A bell-crank lever 49, 48 continuously rocked by a crank 50 on the shaft 39 reciprocates bars 52, 53 which are normally held by latches 56, 60 against the action of springs 54, 58, Figs. 5 and 7. Just before the cutter-shaft is stopped, a cam 135, Fig. 1, thereon depresses a lever 136 fixed to a shaft 137. The lower end of a lever 138 also fixed to the shaft 137 engages with the slotted latch 60, Figs. 1 and 5. The depression of the lever 136 thus withdraws the latch 60, so that an abrupt, shoulder 68 on the bar 53 engages with the pin 45 on the clutch-actuating rod 44 and pushes it to the right, thus starting the rapid feed to shift the work from cutting to sewing position. On the return-motion. of the bar 53 the inclined shoulder 69 thereon encounters the pin 45 which forces the bar 53 downward so that the latch 60 again engages therewith. When stitching position is reached the cam-rise 85, Fig. 7, on the usual auxiliary camelement 38 fixed to the rapid feed shaft 36 initiates through the members 81, 88, 89, 79 the shifting of the usual stop-motion lever 72 to running position, thus starting the stitch-forming mechanism. The link 88, 89 is of toggle formation, so that the starting-connection may be rendered inoperative. A spring-pressed pin 88a on the link 88 yieldingly engages in a recess in the member 89. At the same time a tripping point 161. Fig. 6 on the inner face of the element 38 lifts a lever 162 which in turn withdraws the latch 56 from beneath the bar 52. A shoulder 70, Fig. 5, on the bar 52 thereupon shifts the pin 45 to the left thus declutching the rapid-feed. The bar 53 is raised on the return motion and the latch 56 again engages therewith. At the completion of sewing, the camdeclivity 86 on the element 38, Fig. 7, allows the stop-motion lever 72 to return to stopping position. The stop-motion tooth 75, Fig. 1, has fixed thereto a lateral pin 163 which engages with a slotted lever 165 pivoted at 166 to the bracket 74. A lever 169 pivoted to the lever 165 is yieldingly held against a fixed pin 172. When the tooth 75 rides up the cam-rise 78 a tooth 170 on the lever 169 snaps under a shoulder 174 of an arm 175 fixed to the shaft 137. When the tooth 75 drops into the stop-notch of the cam 77 the tooth 170 rocks the arm 175 and with it the lever 138 and the latch 60 to start the rapid-feed and return the work from sewing to cutting position. Clamps, closing, spreading, opening. The work holder is of the type described in Specifications 10039/14 and 183,873. The anti-clockwise movement of the arm 18, Fig. 1, actuates the lever 16 to close the work-clamp. A lever 131 pivoted at 132 to the frame is rocked by a cam 129 on the cutter-shaft after cutting has taken place so that the end 134 of , the lever pushes forward the lever 32 of the usual togglemechanism to spread the work-clamp. The extremity of a bar 176, Fig. 7, fixed to the workholder is bent to form a cam-incline 177. One arm 170 of a bell-crank lever 179. 180 pivoted to the machine standard is connected to the usual clamp-opening push-rod 181 from which depends the unspreading arm 182. A lever 184 pivoted to the arm 169 is yieldingly held against a pin 186 thereon. Rearward motion of the workholder from sewing to cutting position rocks the lever 179, 180 to push forward the rod 181, thus opening and unspreading the work-clamp. , Starting and stopping gear. The starting-rod 117, Fig. 1, may be operated by a finger-lever 191, pivoted to the fulcrum-block of the left-hand clamp-lever 12. The end 193 of the lever 191 extends under and rocks a lever 194 pivoted at 195 to a bracket 196 on the frame. The lever 194 is forked at its upper end to embrace a pin 197 carried by a collar 198 fixed to the starting- rod. A returning-spring 198<1> is disposed on the rod 117 between the collar 198 and a guidebracket 199 on the frame. A latch-lever 201 pivoted to the frame has an inclined end 202 and a latching-shoulder 203 adapted to engage, under the influence of a spring 208, a pin 204 on the starting-rod and hold the latter in starting position. An arm 206 of the lever 201 is tripped just before the machine stops by a tripping point 207 on the control element 147 to release the starting-rod. Downward movement of the rod 117 is limited by a finger-operated stop-lever 209 pivoted to a bracket 211 on the frame. The lever 209 which is bifurcated to provide offset stop arms 212, 213 at different levels, can be swung on its pivot to position either arm beneath the starting-rod so as to prevent respectively starting of the machine and excessive motion of the starting-rod. The lever 209 is positioned by means of stop-prongs 214 thereon and a stop-pin 215 on the bracket 211.