714 



CHAINWORK. 



Tambour- 

 ing. 



PLATE 

 CXXXVT. 



Fig. 5. 



any other, because the handle, always pressing by 

 its own gravity towards the acute angle below, 

 touched both sides, and consequently left no room 

 for the handle to shake, which would soon have been 

 the case, by mere friction, even in the most accurate- 

 ly fitted bow. Besides this, it afforded a great fa- 

 cility for changing any needle which might acciden- 

 tally be injured, and substituting another with little 

 delay or loss of time. The bar next to E, after be- 

 ing bored, had another thin bar of malleable iron 

 screwed to it, through which a number of small holes 

 were drilled, and tapped to receive small screws, the 

 centre of each small hole corresponding, as nearly as 

 possible, with that which received the extreme pivot 

 of the needle handle. These screws, the heads of 

 which appear nearest to E, were found of very great 

 practical utility ; for if any small variation took 

 place in the length of a needle when placed in the 

 handle, it could be instantly corrected by turning 

 the screw behind, either backwards or forward, as 

 the case required ; and thus all the points of the 

 needles were preserved in the same straight line, and 

 at equal distances from the cloth, notwithstanding 

 any trivial inaccuracy in the setting. Contiguous to 

 the bar furthest from the cloth was a slip of brass 

 cut into the form of a rack, and extending some- 

 what more than the whole length of the frame. It 

 was hung to the bar so as to move freely from side 

 to side, and by means of a small pinion of 16 leaves 

 upon each handle, communicated a rotatory motion to 

 the needles upon their own axes, either from right to 

 left, or vice versa. The teeth being below, neither 

 them nor the pinion can be seen in Fig. 5. ; but 

 the mode of operation is distinctly visible in Plate 

 CXXXVII. Fig. 1. Behind the cloth frame, at a few 

 inches distance, is a cross rail or beam of wood, 

 which carries all that part of the machinery which 

 was appropriated to the purpose of supplying the 

 needles with the thread, or as it is used to be called by 

 the work people, the feeding machinery. On the 

 centre of this beam, at R, was a small frame of cast 

 iron, in which was the wheel work necessary for the 

 rotatory part of the motion. The other motion was 

 a reciprocating one, alternately approaching to and 

 receding from the cloth, which was effected by an 

 apparatus below, part only of which is visible. The 

 use of both motions was as follows : 



1st, In order to throw a loop into the hook of the 

 needle, it was necessary that the thread should pass 

 round the stem of the needle in the interval between 

 the time when the perforation was compleated, and 

 that when the needle returned after receiving the 

 loop. This was performed by a separate set of brass 

 needles similar to those used by weavers for the wea- 

 ving of lappets, and which are described under the 

 article CLOTH Manufacture. The motion of all these 

 needles being entirely the same, they were driven in- 

 to a bar of hard wood at distances equal to those of 

 what were termed the working needles, in the needle 

 frame, so that they might correspond with each other 

 respectively. Consequently a single rotatory or cir- 

 cular motion communicated to this bar, gave a cor- 

 responding motion to every needle which it contain- 

 ed. By these means, after the perforation had taken 

 place, the fir^t motion was a circular one of the feed- 

 ing needle round the working one, which lodged the 

 loop upon the stem of the latter. But as it was ne- 



cessary that the working needle should be shut by a Tambour,, 

 slider, to prevent the barb from injuring the fabric of ' n ' 

 the cloth when returning, it was also necessary, that ""Y"* 

 before this operation took place, the thread should 

 not only be thrown round the stem, but drawn back- 

 wards into the hook. This second operation was ef- 

 fected by the additional apparatus below. 



A third motion was also necessary to insure the 

 certainty of the hook always catching the loop when 

 drawn back ; and as the working needle required a rota- 

 tory motion on its axis, it became necessary that a cor- 

 responding motion should be given to the feeding nee- 

 dle, so that one should be always as nearly as possible 

 in the directly opposite part of the circle to the 

 other. The means by which all these different 

 motions were effected, will be best understood by 

 describing the particular construction of the ma- 

 chinery behind ; and this is more clearly represented in 

 Figure 6. than in any other part of the Plate. The 

 frame which contains all this part of the machinery, 

 is represented at the letters AB, and a small addi- 

 tional frame is placed behind at P, for a certain por- 

 tion of the wheels. The whole of this frame is to 

 be fixed firmly upon the centre of the cross-rail be- 

 hind, and at right angles to the rail, so that the 

 oblique point O may project towards the back part 

 of the cloth, at a few inches distance. The oblique 

 projecting part of the spindle, or axis at O, is de- 

 signed to answer the purpose of any common revol- 

 ving crank, by moving round a given point, and car- 

 rying with it the bar in which the feeding needles are 

 driven ; and this motion is very simply effected by 

 the perpendicular rack D working into the wheel C, 

 which is loose upon the axis. The rack D is fixed 

 to an upright or vertical rod of polished iron, sliding 

 freely in two guides fixed to the rail or beam which 

 carries the whole apparatus. The lower part of this 

 polished rod is worked by the middle treddle, so that 

 when the treddle is forced down by the wiper, the 

 rack descending gives rather more than a full revolu- 

 tion to the wheel C. Attached to this wheel is a 

 circle of brass E, larger in diameter than the wheel 

 C, and furnished with a spring catch G, which rests 

 in the wheel F, which is a ratchet. This, when C 

 is pulled down the spring G, acting upon the ratchet 

 F, which is fast upon its axis, carries it round, and as 

 the spring does not work in the contrary direction, 

 the rack returns for the next stroke, without bringing 

 back the spindle ; which would undo what had been 

 done. Thus the whole revolution of the spindle is 

 uniformly one way without returning. This is all 

 that is necessary for the rotatory motion. 



That motion, by which the feeding needle is al- 

 ways placed in the opposite part of the circle to the 

 working needle, is effected as follows, by the wheels 

 in the small frame behind. On the extremity of the 

 spindle is fixed the pinion I, which revolves along with 

 it, giving motion to the wheel with which it is con- 

 nected, and which is loose upon its axis. To this 

 wheel is fixed the ratchet K, containing only two 

 notches which bisect the wheel, one being at each 

 extremity of its diameter. The spring catch 1 pres- 

 sing on the circumference of the wheel, catches each 

 of these notches in succession ; the effect of which 

 will be immediately seen. The wheel L is fast upon 

 the axis, and is wrought by the rack M, which is 

 screwed to a cross bar deriving its motion from the 



