GB918436A - Apparatus for operating the mechanism-actuating levers of a sewing machine - Google Patents

Abstract

918,436. Sewing machines. SINGER MANUFACTURING CO. July 10, 1959 [July 23, 1958], No. 23762/59. Class 112. [Also in Group XXIV] For operating with a constant force the spring-biased work-clamp lifting and starting levers of a group-stitch sewing machine, racks 36, 55 connected thereto through chains 52, 67, respectively, are slidable endwise in and rotatable with individual guides 35, 56 which are mounted on pivoted shafts 34, 57, respectively to move the racks into and out of driving engagement with a pinion 27 driven, through a reduction gear 16 and a friction coupling by an electric motor 13 which may also drive the machine. The racks which are normally spring- biased out of contact with the pinion, are engaged therewith by solenoids, 20 only shown, which actuates a lever 42 pivoted at 41 and having an adjustable bolt 44 which bears on the rack 36 between rack guide-pieces 46. The other solenoid 21, not shown, actuates a similar lever 62 to engage the other rack with the pinion. The biasing springs for the rack guards 35, 50, shown only for guide 56, comprise a leafspring 59 fixed in an adjustable mounting 60 and bearing on an arm 58 secured to the shaft 57. Stops 48, 49 and 66, 68 limit the stroke of the racks 36, 55, the friction coupling slipping on engagement of the upper stop with the associated guide. The control switch for the work-clamp-control solenoid 20 is wired in series with an interlock switch which is opened by operation of the normal machine start control, so that after starting, the solenoid 20 cannot be energized to lift the work-clamp. Energization of solenoid 21 when the work clamp is raised, engages rack 55 with the then stationary pinion 16 whereby starting of the machine is prevented.