BRITISH PATENT 1.133 - 1857
1.133 John Henry Johnson, of 47, Lincoln's Inn Fields, in the County of Middlesex, and of 166, Buchanan Street, in the City of Glasgow, North Britain, Gentleman, for an invention for improvements in sewing machines.This invention relates to that class of sewing machines wherein the stitch is composed of two threads, the one being worked by a vibrating needle, whilst the other thread is looped therein underneath the fabric by means of a peculiar circular or discoidal shuttle or spool case. According to one arrangement of apparatus a suitable bracket is fitted or formed on the top of the bed plate, for carrying the vibrating needle arm or lever and an auxiliary lever, the two levers being so connected that when the needle arm descends to enter the needle into the cloth the auxiliary arm rises and draws the upper thread which is passed through an eye in its extremity. Below the bed plate is a diagonal or oblique driving shaft, working in suitable brackets and fitted or formed with a cam or crank for working the needle arm through a connecting rod. This abaft carries also a grooved driving pulley which receives motion from any convenient source by means of a driving strap or band. A bevel cam is also fitted to the shaft for the purpose of giving motion to any convenient arrangement of cloth feeding mechanism ; on the extreme upper end of this shaft is fitted a driving plate, for imparting a rotary motion to the discoidal shuttle or spool case, which revolves freely In a circular race or holder. The spool case and race are not at right angles to the shaft or parallel to the plane of the driving plate, which latter is fitted with projections or pint taking into corresponding holes in the spool case, so as to transmit a rotary motion thereto when the driving plate revolves, these projections or pins being at right angles to the face of the driving plate. By placing the spool case at an angle, the pins will leave it on one side as it revolves and will allow of the play of the needle and passage of the needle thread without interruption. The spool case is made circular or discoidal and carries the spool in the centre thereof and is formed with two noses between which a recess or throat is left, so that the needle thread may be caught on the revolution of the spool case and being carried round, the two threads, namely, the needle thread and the spool thread, will be interlocked and form the stitch desired. A radial arm, which may be tightened as desired and through the end of which the spool thread passes, is fitted to the centre or the spool and revolves as the thread is drawn off, the amount or friction or drag being adjusted according to the degree of the tension required. The needle thread is drawn in an opposite direction to the movement of the needle, by means or the auxiliary lever before referred to, so that tho stitch may be completed when the needle is at its lowest position. A communication.
Letters Patent sealed. April 22, 1857