Patent GB-254636-A (GB)
Title: Improvements in sewing machines
IPC: D05B3/18
Filed: 1926-03-01
Abstract: 254,636. Rosenman, L. March 1, 1926. Eyeleted tape-attaching machines; workguides.-A machine for attaching to garments &c. tape to which the loops of hook and eye fasteners are alreadv secured, is provided with stop devices for engaging the fasteners so as to govern the intermittent advance of the tape past the stitching mechanism, and avoid contact of the needle with the fasteners. Indicator devices for the number of stitches and visual electrically-operated alarm devices for notifying a lack of synchronism between the tape. feed and stitching mechanism and of the approach of a tape end are provided. The tape is fed to stitch-forming devices of known type indicated at 12<1> over a guide plate 15 on which are guide-ribs 16, and may pass through a hemmer 20 and a guide-piece 21. Feed by wheels; counting mechanism, applications of.-A lower feed roll 24 and upper feed roll 27 are mounted on shafts 23, 26 having meshing gear-wheels 28, 29, the upper shaft 26 being mounted in bearing blocks 25 supported for vertical movement in the frame. The rolls are advanced intermittently through the usual stitch length, and also at intervals through a greater length, so that the needle jumps the sides of the loops of the eyes by means comprising a pawl 32 carried by a lever 31 and engaging a toothed wheel 30 on the shaft 23, the lever 31 being oscillated by an eecentric 33 on the sewing shaft 14. A second wheel 35 on the shaft 23 is provided with teeth 36 arranged in pairs at intervals of 90 and driven by a pawl 38 actuated by an eccentric 39 of double the eccentricity of the eccentric 33. The tape is advanced normally by the movement of the wheel 30, but the parts are so proportioned that on the approach of an eyelet to the stitching point the first of a pair of teeth 36 is engaged and the shaft 23 moved double the normal distance, thus causing the needle to make a stitch of double length and miss the eyelet loop, the second of the pair of teeth causing the needle to avoid the further side of the loop. A gauge 41 is provided to facilitate the placing of the tape in correct position and also to indicate the relative position of the needle and an eyelet at any time, the position of the numbered indicator points relative to an eyelet passing them corresponding to the position of the needle and the eyelet next to it. A second indi. cator device comprises a wheel 42 mounted on a shaft 43 driven from the shaft 23 and making a revolution for each quarter revolution of the shaft 23. The wheel 42 bears numbers corresponding to the numbers of stitches between successive eyelets. A positive stop device for preventing the overrunning of the tape comprises a stoppiece 54 extending across the tape and projecting from an arm 53 carried by a shaft 52. The stoppiece is moved into position so that it will engage an eyelet, if the latter is displaced from its correct position, by a cam 55 on the shaft 23 operating through mechanism including a lever 57, a link 62, and a lever 61 on the shaft 52. A tape-tensioning means is provided comprising a pivoted lever 89 stressed by a spring 89<111> and having an extension 89<1> which passes beneath the tape. Means for releasing the pressure of the feed rolls when the tape is engaged by the stop 54 comprise sliding rods 64 which carry the bearing blocks 25 of the upper feed-roll shaft and are actuated to lift this shaft by a cam 68 mounted on a shaft 67 held in normal position by a crank and .spring. A sleeve 77 on the shaft 73 is caused to shift longitudinally through the movement of a laver 81 actuated by a cam 84 so that a projection 78 on the sleeve comes into engagement with a nose 79 on the connecting rod 40 by which the quick feed movement is effected. Alarms, applications of.-An alarm device is provided for giving warning of misplaced tape and comprises a pivoted arm 94 which is moved by engagement of a loop on the tape to make contact between members 97, 99 in the circuit of a lamp 92. Included in the circuit is a cam 102 on the shaft 23 having four projections which engage a contact brush 104. When the feed of the tape proceeds manually the contacts 97, 99 and 102, 104 are not made at the same time, but if the tape becomes displaced they are made together and the lamp is illuminated. A further indicating means for giving warning that the end of the tape is reached or that a join between two sections of tape is approaching comprises a pivoted arm 110 which rests on the tape and moves a contact finger to complete the circuit of a signal lamp, either when the support provided by the tape is removed or when the extra thickness of the join deflects it in the opposite direction.