Patent GB-668896-A (GB)
Title: Improvements in and relating to overedge sewing machines
IPC: D05B71/00
Filed: 1949-12-01
Abstract: 668,896. Overedge sewing-machines. UNION SPECIAL MACHINE CO. Dec. 1, 1949 [Dec. 7, 1948], No. 30846/49. Class 112. Frames; work supports.-The frame has a main oil-tight chamber 20a, Fig. 3, and an auxiliary chamber 21, and comprises a base plate 10, a lower section 11, an upper section 12 having a part 33 carrying the head 40, and a detachable cover 15. Formed on the part 11 is a pedestal 23 which may be provided with a horn 24 for tubular work. A bracket 31 provides a depression in the wall of the auxiliary chamber to permit the mounting of a thread-tensioning device 30, and a spring pressed cover 188 at the front of the machineprotects the loopers. A work support 25, Fig. 1, is pivotally mounted on a pin: 26, and a cloth plate 36, Figs. 2 and 7, is hinged about a pin 37 in a boss 38. Presser-bars.-The presser bar 41, Fig. 2, is lifted by a lever 45 mounted on a shaft 46 having a cranked end 48, Fig. 1, connected with a pedal or a knee control. Stitch forming.-A curved needle 69, Fig. 3, carried by an arm 70 on a rock shaft 71 driven from the main drive shaft 51 by a pitman 78 enters the work perpendicularly. A looper 80, Fig. 2, mounted on a rock shaft having a cranked arm 89, Fig. 3, is connected to the drive shaft by a pitman 92. A cranked overedge looper 95 is given bodily and pivotal movement to form three thread overedge stitch. As shown in Fig. 2 the looper 95 is pivoted at 96 to an arm 97 on a rock shaft 98, and is pivoted to an arm 102 on a rock shaft 103 driven from the main drive shaft by a pitman 108. The looper 95 may be replaced by a spreader having a notched end to receive thread from the under looper. Feeding work by dogs.-The feed-bar 112, Figs. 7 and 8, carries a main feed-dog 110, and is given lift movements by an eccentric on the main drive shaft. Feed movements are given to the feed-bar by an extension 116 on the bar pivoted at 117 to an arm 118 on a rock shaft 119 actuated by a pitman 141 from the main drive shaft 51. The connection between the pitman and an arm on the rock shaft permits adjustment of the length of feed. The auxiliary feeddog 111 is carried by a rod 121 sliding in bosses on the feed-bar. Differential movement is given to the auxiliary feed-dog by a rod 127 pivoted to the rod 126 and adjustably pivoted to the arm 118 at 128. Trimming.-A blade 149, Fig. 8, is adjustably fixed to the pedestal 23 and co-operates with a movable L-sectioned blade 153, Fig. 2. The blade 153 is adjustably carried by an arm 156, Figs. 3 and 7, on a rock shaft 158 driven from the main drive shaft by a pitman 167. Lubricating.-A disc 172, Figs. 3 and 7, fixed to the main drive shaft 51 dips into oil at the bottom of the oil tight chamber 20a, and on rotation disperses oil as a mist within the chamber. Oil drips from projections 175, 176 to lubricate parts of the mechanism within the chamber. Some of the mist is conducted by wick-filled tubes 177, 181 to the feed mechanism housed in the auxiliary chamber 21. Oil collecting at the bottom of the chamber 21 is conveyed by wicks 182, 185 to lubricate the connections of the looper 95 to the arms 97, 102 on the rock shafts 98, 103. Needle bearings for the main drive shaft, and the rock shafts 71, 158 are supplied with heavy grease by means of grease nipples. The chamber 20a is fitted with an oil gauge 195, Fig. 6 (not shown).