GB873377A - A driving and positioning mechanism for a machine for operating about the edge of a mattress or similar article - Google Patents

Abstract

873,377. Sewing machines. UNITED MATTRESS MACHINERY CO. June 26, 1959, No. 22081/59. Class 112 [Also in Group XXIII]. Apparatus for sewing around the edge of a mattress comprises a sewing machine, a rectangular work-supporting table, means on the machine and table for supporting the machine and guiding it around the edge of the table, and driving means for advancing the machine around the table edge and comprising a driving gear on the machine and co-operating stationary means supported from and extending around the table, said supporting and guiding means comprising a guide rail having straight portions connected by curved corner portions, a pair of machine supporting rollers riding on the rail and pivoted on the machine for movement towards and away from the table, the rollers being flanged for engagement with inner and outer surfaces on the rail, adjustable means on the machine for limiting the outward movement of the rollers, and a further roller supported by the machine and engaging a surface of the rail positioned inwardly of the supporting rollers to prevent rotational movements of the machine. A sewing machine 20 is adapted to sew around the top edge of a mattress supported on a table 24. The latter is carried by four posts 160 extensibly mounted in respective table legs 30 which in turn support an upper L-section guide rail 26 and a lower guide rail 28. The sewing machine is mounted on a base 22 which is supported on the vertical limb of rail 26 by two flanged rollers 32, 34 journalled on arms 36, 38 respectively connected to base 22 by vertical pivots 37 and 39 (not shown). Adjustable stop screws 150 on base 22 limit the outward movement of arms 36, 38. A roller 118, journalled on a bracket 122 carried by base 22, engages the edge of the horizontal limb of rail 26. A roller 42 on base 22 engages the vertical outer face of rail 28, and a guard plate 44 on base 22 extends beneath rail 28. A sprocket chain 46 extends around the table legs below the rail 26 and is supported at the corners by sprocket segments 48. Chain 46 passes around sprockets 50, 52, 56 mounted in base 22. Sprocket 50 is positively driven, Sprockets 52 and 56 are idler sprockets, the former being journalled in a slidably mounted bracket 54 biased by a spring 60 to tension the chain. A roller 132 engaging the outer face of rail 26, is journalled on an arm 136 pivoted at 138 on base 22. A spring 140 acts on arm 136 to bias roller 132 against rail 26, whereby base 22 tends to pivot counterclockwise about roller 118 to engage the outer flange 148 of the trailing support roller 32 against the outer face of rail 26. A roller 126, coaxial with sprocket 56, is adapted to engage cams 128 mounted at the respective corners of rail 26. Sprocket 50 is carried by a shaft 64 on which is slidably mounted the driven element 66 of a clutch, the driving element 68 of which is connected via a gear box 72 and clutch 84 to a shaft 74 driven by a belt 78 from a motor 82. Clutch 84 is controlled by a linkage 88, 90 from a knee pad 86. An annular shoulder 98 on element 66 is engaged by a pin 96 on the lower end of a slidable bar 95, the upper end of which is connected to an eccentric pin 100 on a rock shaft 102 turnable by a handle 104 through 180 degrees for engaging or disengaging element 66 from element 68. When element 66 is disengaged, a sliding bolt 106 may be passed through an aperture 114 in bar 95 to engage sprocket 50 for locking base 22 in position. The screw-threaded lower ends of the posts 160 engage internally screw-threaded sleeves 162 journalled in the respective legs 30. Sprockets 172 on the sleeves are interconnected by a chain 170. One of the sleeves is driven via gearing 164, 166 from a reversible motor 168. The operating lever 176 of a direction switch 174 mounted on the underside of table 24 is connected to an endless cord 178 passing through an eye 180 at each corner of the table, whereby the cord may be pulled in one direction or the other for moving the lever 176 from an intermediate neutral position in a direction for either raising or lowering the table.