Patent GB-191023478-A (GB)
Title: Improvements in or relating to Sewing Machines.
Inventor: BOULT ALFRED JULIUS
IPC: D05B15/04
Filed: 1910-10-10
Granted: 1912-01-10
Abstract: 23,478. Boult, A. J., [United Shoe Machinery Co.]. Oct. 10. Boot - sole sewing machines; fair - stitching; presser - bars, locking, lifting automatically, and lifting non-automatically. - The depending arm 4, Fig. 1, of the presser-lever 3 is linked to a floating lever 6, which is urged rearwards by a spring 12, is pivoted upon a longitudinally sliding rod 8, which may be locked from longitudinal movement and is linked at its upper end to a cam lever 10. The presser is held on to the work normally with the light pressure due to the spring 12 acting upon the floating lever 6, the rod 8 being unlocked and a pivot for the floating lever being provided by the link connexion between it and the cam lever. At the close of the feeding movement, the rod 8 is locked, and thereafter provides a pivot for the floating lever while it is positively actuated by the cam - lever 10 to transmit a work-clamping movement to the presser. Prior to each feeding movement, the lock on the rod 8 is removed by a cam lever 26. For the purpose of locking the rod 8, it is provided w i t h steep screw-threads, and engages a nut which is held from axial movement by being confined between the two parts of the guide - bracket 15. A locking - frame 17 surrounds the nut and is linked by a rod 19 to a lever 20 pressed upon by a spring 24, which tends to hold the locking- frame tilted so as to leave the nut free to rotate and thereby to leave the rod 8 free to move axially. Prior to each presser-locking movement, the cam-lever 26 is actuated to contact with and rotate the lever 20, and thereby to tilt the locking-frame 17 into its rod-locking position. The presser can be freed from its locked position by the lifting-lever 28 pivotally mounted upon the presser-lever 3. This lever has a projecting part 30, to which is linked a rod 31 having a slotted end surrounding the pin-connexion between the locking-frame 17 and the lever 20. Pins 33, 35 limit its movement relative to the presser. In its first movement, the lever 28, by means of the rod 31 and in opposition to the spring 24, tilts the locking-frame so as to free the rod 8. This movement brings the pivotal connexion between the projection 30 of the lifting-lever and the rod 31 into axial alinement with the presserlever pivot so that while the presser-lever moves with the lifting-lever in its further movement no further movement of the rod is thereby occasioned. Upon release, the initial movement of the lever 28 relative to the presser-lever is reversed by a spring 34. The presser is lifted when the machine is stopped, by means of the lever plate 240, which, on a reversal of the motion of the machine, is engaged by a notch in the boss on the shaft 11, and is lifted from the position shown into the alternative position. Thereby a lever 241 is moved outwards from the shaft and engaging a lever 254 operates the hand-lever 28 to lift the presser. Perforating-devices; feed by awl.-The awlcarrier, Fig. 31, is formed integral with a spindle which is mounted to slide and oscillate in bearings formed on brackets 42, 43, Fig. 8. The ends of the spindle are coned to receive antifriction pieces 46, and the whole is held between the ends of a pair of levers 44, 45, which are joined together by a link 47. A pin 48, uniting the link 47 and the lever 45, has an eccentric portion in engagement with the eye of the link 47 and the parts may be adjusted for wear &c. by rotational adjustment of the pin. The lever 44 is prolonged and is coupled to a link 49 of a toggle, the outer pivot of which is formed in a frame 53. The middle pivot unites the toggle with an operating train of levers 51, 52. In order to vary the feed, the frame 53 is turned upon its own pivot from a usual feed-regulator by linkages 57, 56, 55, 54. The pivot of the frame 53 is co-axial with the limiting position of the centre pivot of the toggle, so that the rotation of the frame 53 to regulate the feed does not alter the final position of the levers 44, 45, and the awl at the end of a feeding operation is always in line with the needle. The awl-driver is mounted to oscillate upon the carrier spindle 41, but does not participate in the axial movement. It is divided into two parts 63, 64, Figs. 32 and 33, which fit over the carrier from opposite sides and are caused to oscillate together by pins 65 on the part 64 which engage with holes in the part 63. The driver is cut away to provide flat diametral surfaces 66 which engage corresponding surfaces 67 on the carrier. The feedregulating lever 58, Fig. 1, moves over a perforated plate and is retained in position by pins secured therein. A cam-plate is mounted on the lever to engage with the stop-pins, and by the rotation of this cam the feed can be finelv adjusted. The edge of the perforated plate has a V-groove 59, and the corresponding sharpened end of a plunger carried by the regulating-lever is forced into the groove by a spring to hold the lever frictionally in place. The awl is oscillated from a uniformly-rotating crank 84 through link 87, lever 85, link 88, and lever 86, Fig. 5, and lever 86 and link 89, Fig. 1. This mechanism, owing to the relative positions of the levers 85, 86 and link 88, causes the awl to make a short ineffectual oscillation when retracted furthest from the work, and thereby to remain withdrawn for substantially half of each cycle of operations. Feed by laterally-moving edge-guides. - The distance of the seam from the edge of the sole is varied by the lateral movement of an edgeguide 197, Fig. 1, during the stitching operation. The edge-guide is adjustably secured to a lever 198 pivoted on the machine frame. To this lever, a block 200 having a cam-groove 201 is adjustably secured by a pivot pin and an adjustably screw-connexion. A bowl on the end of a hand-operated lever 202, 204 engages with the cam-groove, and the movement imparted to the lever thereby is determined by the adjustment of the block 200 upon the lever. In place of the lever 202, a vertically-arranged shaft having an arm engaging the groove 201 may be used. Then in place of the adjustable connexion, between the block 200 and lever 198, screw stops for limiting the movement of the hand-lever of the vertical shaft may be provided. The hand-lever may be connected to a knee-lever, and be held normally in one extreme position by a spring. A latch may be provided to hold the lever when depressed. Needles, driving; needle-shields. - The hook needle is driven from a uniformly rotating crank 77, Figs. 1 and 5, by linkages which produce substantially a dwell in the movement of the needle during nearly half of each cycle of operation in a manner similar to that of the awl-drive. The crank 77 is linked by a pitman 82 to one arm 81 of a bell-crank lever, and the other arm 81<1> of this lever is linked to the needle-carrier, and so related to it that the pivot 83 between the link and the lever arm 81<1> crosses the line joining the hub of the lever 81 and the pivot connexion between the needlecarrier and the link, as the needle approaches one extreme position. As a consequence of this arrangement, the needle is caused to make a short ineffectual stroke when retracted furthest from the work. A needle-guide 72, Fig. 18, is actuated in a usual way by a cam-lever 73. Fig. 5, toothed to engage with a pinion 74 integral with a second pinion gearing with teeth on the hub of the needle-guide carrier. Needles, hook, threading-devices for. - The thread is laid in the barb of the needle by means of a thread-finger 90 and a looper 91, Fig. 5. The thread-finger is formed upon the upper end of an arm having at its lower end a pin - and - slot connexion with the machine frame and pivotally connected at an intermediate point to an inclined cam-actuated slide 92, mounted in a guide-box secured to the machine frame. The inclined slide may be replaced by a link connecting the finger-arm with the cam-lever. The looper 91 is adjustably secured within a socket extension of a rod 95, Fig. 8, supported at its forward and rear ends by cam-actuated levers 97, 98. Lock-stitching by hooks. - A rotary hook which is rotated three times in each cycle of operation, is supported in a race 101, Figs. 1, 5, and 18, which engages an annular groove in the periphery of the hook. The forward part of the hook-body forms a toothed bevel-wheel which is driven by a bevel-wheel 102 on an auxiliary shaft 103. The toothed part of the hook-body is enclosed by a casing 112 integral with the race and having a tubular extension projecting into the hollow centre of the hook. The spoolcase 106 is supported within the hook by means of an annular rib which runs in a race in the inner wall of the hook. The spool is slipped into the spool-case by way of the tubular extension of the case 112, and is removed from the spool-case by means of a hand-lever 118, Fig. 5, the end of which passes through a hole in the bottom of the spool-case. The spool-case is held from rotation by means of two sliding pins 111 mounted in the tubular part 112 and notched to engage a cam-rib projecting inwards from the hook, which moves the pin alternately from engagement with the spool-case to permit the passage of the needle thread-loop. The movement of the thread upon the hook-nose 105 is limited by a ridge 116, Fig. 18, formed a little to the rear of the thread-engaging point. The thread is tensioned by a leaf-spring partly surrounding the spool-case. The spring is slotted so that it can be adjusted upon its securing- screw, and is further kept in place by an abutment which engages a recessed portion of the spring. The needle-thread is brought up to the hook at the rear and is spread for engagement with the hook by a thread-finger 131, which is secured to a rod 132 pivotally-connected at its rear end to a cam-actuated lever 133 and at an intermediate point carries an adjustable arm 134 pivotally-connected to a second camactuated