Patent GB-1466166-A (GB)
Title: Overedge sewing machines
IPC: D05B1/20
Filed: 1974-04-25
Abstract: 1466166 Overedge sewing machine MERROW MACHINE CO 25 April 1974 [26 April 19731 18102/74 Heading DIG An overedge sewing machine comprises a housing (10, Figs. 1 and 2 not shown) a horizontal work support 100 thereon, feed means (274, 276) stitch forming elements comprising a needle (92) a lower looper 126 and an upper looper 156, separate mounting means supporting the needle, the lower looper and the upper looper, a drive means operating the stitch forming elements in synchronisation with the feed means also driven thereby, the drive means comprising a horizontal main drive shaft 30 extending through the housing with its axis perpendicular to the feeding direction, an auxiliary drive shaft 60 disposed in the housing with its horizontal axis at right angles to the main drive shaft, gears 76, 82 connecting the shafts, each stitch forming instrumentality being drivingly connected by one of three planar bar linkages to one of the shafts. Needles, driving: loopers, driving. The needle (92) is mounted on an arm (96, Fig. 16, not shown) mounted on a shaft 98 rocked by arm 112 and connecting rod 116 connected to a crank pin (122) on main shaft 30. The lower looper 126 is mounted on a rock shaft 134 oscillated (Fig. 18 not shown) by the bar linkage 138, 146 (152) the latter being a crank on the auxiliary drive shaft 60. The upper looper 156, Fig. 17 comprises a looper rod 160 supported in a fixed bearing sleeve 164 to be reciprocated therein by link 184 pivoted at 186 to the housing and connected at 190 by a rod 188 to crank 198 on the shaft 60. Work feed by dogs, differential feed The two feed dogs (274, Fig. 6 not shown) 276 are mounted on separate feed bars (280), 284 of similar construction and arranged side by side. Three scotch crank mechanisms affect each crank, slots 348, 354, 286 receive respective blocks 344, 292, 352, the first two blocks being mounted directly on crank pins 342, 292 while block 352 engages a crank pin (350 Fig. 4 not shown) through separate eccentric members 356 whose relatively eccentricity may be varied (Figs. 5A 6A not shown) to produce differential feeds by the respective dogs as the feed raising shaft 294 and pivot shaft 336 are respectively operated from two armed connecting rods 318, 224 engaging shaft 30. Shafts 294 and 336 carry the crank pins 292, 342 on which the first blocks are provided. Work severing The machine is provided as usual with a work trimmer comprising [Figs. 12-15 not shown] a movable knife (220) cooperable with a ledger blade (206). The knife is secured (Fig. 15) to a bracket (216) having a comb joint inter-relation, (228, 224, 230, 222) comprising tapered slots cammingly engaged by a set screw (242) tapered at 244, with a cutter arm (226) secured to a bushing (256) rotatable on a presser foot mounting shaft (254), the bushing arm (258) being connected by rod (264) to a crank (270) eccentric to the axis of shaft 30. Lubricating (Figs. 9, 10 not shown) Shaft 30 is surrounded by a housing (372, 374) provided with eccentric cut away portion (382) and a radial piston (400) spring urged to abut the shaft. An oil supply pipe (394) depends into a recess (396) in the oil sump (20); it is stated that on rotation of shaft 30 within the housing oil flows through passage (384, 386, 406) to lubricate moving parts, including the differential feed adjuster. Adjustable bleeds are provided. The connecting rod 146 of the lower looper drive has a spoon (416) providing splash lubrication.