Patent GB-633040-A (GB)
Title: Improvements in or relating to machines suitable for use in the manufacture of shoes
IPC: D05B15/04
Filed: 1947-12-10
Abstract: 633,040. Sewing-machines. BRITISH UNITED SHOE MACHINERY CO., Ltd., and MAWBEY, L. Dec. 10, 1947, No. 32555. [Class 112] Boot-sole sewing-machines; rotary horns.-In a machine having a work-supporting horn which presses the work against a work-engaging device under the action of yielding means and which is moved away from the workengaging device during each stitching cycle to allow feed of the work, means are provided for causing the horn to be moved a uniform distance from the work irrespective of the work thickness; the pressure of the yielding means on the horn is relieved during this movement, and the horn is locked against movement while the needle is penetrating the work. Means may be provided for temporarily increasing the movement to accommodate sudden increases in work thickness. In the arrangement shown, for a machine similar to that described in Specification 476,044 but having a rotary horn, the horn 9 is carried on a bar 15 vertically slidable in the machine frame 185 under the action of a lever 23 with a forked end embracing a block pivoted on a pin in a recess in the bar. The lever 23 is pivoted at 27 to a lever 25, and its rear end carries, on a pin 29 a block engaging a fork in one arm of a crank 33, 37 which is acted on by an adjustable compression spring 53 to press the horn upwards, the pin 29 also connects the lever to a link depending from a locking bar 59 which can be clamped by an eccentric 91 on a spindle 65 actuated by an arm 67 from a cam-controlled lever 75. The lever 25 is pivoted at its rear end to a pair of links 99 engaging an arcuateslotted measuring arm 105 pivoted at 107, and has at its middle a pin 129 which connects it to a pair of arms 131, on a shaft 35, with extensions 133 acted on by tension springs 135 ; the pin 129 also carries rollers 137 resting on cam faces 139 on the upper ends of levers 145 fixed on a shaft 143 connected to the starting treadle and held by a spring against a clockwise stop on the frame. The arm 105 is lifted at each cycle, to lower the horn to allow feed of the work, by a cam-actuated link 125 ; the amount of movement of the horn is determined by the position of the links 99 along the arm 105, which is controlled by a treadle-rod 113 acting through a crank and link 108 against a spring. The shaft of the crank has an arm which works between two adjustable stops ; the spring normally keeps the parts in one extreme position, so that the movement of the horn is constant, but if a sudden thickening of the work has to be encountered the treadle is depressed to shift them so that a much bigger movement is given to the horn, followed by a return to the normal movement when the treadle is released for working along the thicker part of the work. The lock 91 opens after each feed movement to allow the springs 53 to adjust the horn to any change of work thickness. The treadle lever 145 has an arm 155 attached to a cam bar 159 which is guided by a roller 159 and engages rollers on the link actuating the lever 75 and on a pleater-controlling lever 169 actuated from a cam through a link 171. When the machine is at rest, the levers 145 are at their clockwise limit, so that the horn is lowered by the springs 135 to allow work to be removed or put in place, the pleater is moved clear (its cam lever being raised from the cam) by a cam 165 on the cambar 157, and the bar 59 is unlocked and in its lowest position. As the treadle is depressed to start the machine, the cams on the levers 145 raise the lever 25 about its connections to the links 99 to raise the lever 23 thus bringing the horn against the work and then compressing the springs 53 ; the cam-bar 157 then allows the lever 73 to move, to lock the bar 59, and allows the pleater to move to the operating position. The work-foot is formed with a rectangular aperture in which the needle works and moves with the work, so that soft material is held down all round the needle. Frames.-The horn actuating and locking parts are enclosed in a portion 185 of the machine frame, provided with a hinged cover 189, and the upper part of the machine is enclosed in a hood, with a front cover hanging on pivots at the top ; part of the hood extends forwards at one side of the front cover. A covered opening is provided in the rear of the hood. Specification 515,964 also is referred to.