348 



SKWIXCi-MACHINK 



The upper thread of the lock-stitch machine, para- 

 ing from the spool as it is purchased and placed 

 upon the 'spindle' or ' spool-nolder ' upon iln> .-inn 

 of the machine, through the ' thread-check,' around 

 the ' tension-pulley ' or between the ' tension-discs,' 

 through the 'thread-guide,' 'take-up,' and 'leader' 

 (theae are of various devices), finally through the 

 eye of the vertical needle, is carried by the descent 

 of the needle bar downward through tin- cloth and 

 the loop of the under thread, and bv the upward 

 motion of the needle i- again brought wick through 

 the cloth, drawing the midrr thread upward to the 

 centre of the fabric, w here, by a prouer adjustment 

 of the tension of tin- two thread-, they are locked, 

 making a perfect stitch, exactly the same upon 



Fig. 



both sides c if t ho cloth. Fig. 2 represents the ' lock- 

 stitch.' than which nothing letter is required for 

 sewing. I'.y this stiU'h an elastic and durable seam 

 is made, which even the skilled operator finds diffi- 

 culty in ripping. It will not unravel, ofthisclass 

 of machines there is also a large variety, which may 

 be subdivided into two classes those using the 

 vibratory, oscillatory, or shuttle motions, and 

 those constructed entirely upon the rotary motion 

 principle. 



The Singer and the Wheeler & Wilson are the 

 leading exponents of these two classes of lock- 

 stitch machines, and are the two great competitors 

 in the markets of the world. There are many 

 other excellent lock-stitch machines whose names 

 are familiar both in homes and workshops, as i he- 

 Howe, Kemington, Florence, Weed, Doinesiic. 

 American, iVc. . it he last-named using a rotating 

 shuttle), all of which make the lock stitch in the 

 centre of the fabric, and are constructed either 

 upon the principle of the vibratory or oscillatory 

 shuttle motion or upon that of the rotary motion. 



shuttle has a long beak, the object of which is to 



hold the loop until the needle has been lilted 

 entirely out of the goods. While the needle is out 

 of the -iMnl- the loop is opened by the body of the 

 shuttle siillieicntly to j>ass through, the thread 

 luring pulleil down through the net-die's eye and 

 the opening through the j^'oods left free for the 

 thread to play in, a vast friction and strain upon 



Fig. 3. 



a, TlbnUng nhiiUIr ; t, OMllUUng nhuUlc ; c, bobbin of <willtlng 

 fthuttle. 



Fig. 3, a. represents the vibrating or reciprocat- 

 ing shuttle of tin- Singer machine. < Iriginally all 

 of the Singer machine* were constructed with 

 this mechanical device for the supply of the 

 under thread, the shuttle vibrating beneath the 

 baster-platc. ' The oscillating shuttle was adopted 

 by the Singer Manufacturing Company in 1878. 

 Tne loop is formed and caught by the beak of the 

 -buttle as in the reciprocating shuttle. The 



Fig. 4. 



a, routing book, bobbin-holder with bobbin, Ac.; b, bobbin 

 Mid bobbin-cue. 



the thread being thus avoided. Fig. 4 represents 

 the sewing device of the \\ heeler \ Wilson family 

 machine, consisting of a rotating hook, formed by 

 a disc of polished steel, with 'slot' cut in it- 

 periphery and its pointed ends curved, which being 

 attached to the horizontal pulley shaft revolves 

 with it, giving off from its In-veiled edge at each 

 revolution a loop, formed by the upper thread 

 on the outer side of the needle as it descends 

 through the 'slot.' This loop is caught upon the 

 rotating hook and carried along with it nliont two- 

 thirds of the way round, and, as it slips oil' and the 

 thread is again partially drawn up by the rising 

 needle, crosses the iHilibin, catching its thread 

 and drawing it upward, thus forming inter- 

 locking loops, which tightly drawn form 

 the stitch. The IniKliin is perfectly free, is 

 neither pivoted nor placed upon an axle, 

 but is fitted in a concave holder upon the 

 outer side of the rotating hook and revolves 



in the op|M>site direction fr the hook, thus 



securing a proper tension and giving off at 

 each revolution sufficient thread for one 

 stitch. Fig. 5 represents the sewing mechan- 

 ism of the ma 1111 fact 11 ring machine of this 

 make ' No. I'J' constructed with a view 

 of securing the highest speed, accuracy, 

 and economy of power consistent with the 

 rotary motion. The bobbin is placed upon 

 a 'Mud' or 'axle' in the centre of the 

 rotating hook, and the thread is ,lrawn 

 through a 'slot' in the periphery of the 

 bobbin-case, and held securely by a spring 

 or passed through an eyelet. 



This machine is also constructed with a 

 ' cylinder feed' specially adapted to the 

 vamping of shoes (the vamp lieing stitched 

 just as it comes from the pasting block), 

 which i.s easily changed into a ' Hut bed machine 

 by means of an adjustable platform, adjusted 

 over the cylinder feed ; and, as represented in 

 fig. fi, it maybe constructed as a three threaded 

 machine, having two parallel threads which by 

 its peculiar mechanism become interlocked alter- 

 nately with the under thread, forming a zi^ 

 -I itch upon the. under side and presenting two 

 parallel rows of stitching upon the upper surface. 



