544 



CA R P E T. 



Carpet, pinion Y ; but in the latter case, a small shaft must 

 w ' extend from A as far as B, and the catch may be 

 CXXX worked by a small crank on its extremity. At the 



Fig- 6 > ? k*" 1 ^ anc * ^ t ^ ie l om > l ^ e mov "i n power is applied. 

 The first motion is communicated to the fast and 

 loose pullies at L, by a belt or band from a drum or 

 pulley at O, which takes its motion directly from the 

 moving power, whether water, steam, or horses. 

 The band may be guided from either pulley by the 

 levers at MM, and the loom instantaneously set in 

 motion or stopped, either above or below. The cross 

 shaft at K may receive all the wipers or craaks ne- 

 cessary for every motion, and these may be applied 

 according 1 to the choice of the engineer or mechanist, 

 as in other power looms, regard being paid to the 

 succession in which the leaves of the front mounting 

 are to be moved. Four treddles are represented be- 

 low at NN ; and in the present plans these are to be 

 moved in the succession of the numerals 1, 2, 3, 4, so 

 that it is supposed that one revolution of the shaft K 

 will work the whole four treddles. The wipers here 

 are supposed to be projecting pieces of iron, at right 

 angles to each other, and furnished with small rollers 

 to diminish the friction. In fabrics so stout and 

 elastic as woollen carpets, these may do sufficiently 

 welli or the wipers may be constructed by the rules 

 given for power looms, in the article CLOTH MANU- 

 FACTURE. These are the whole motions, and it may 

 now be proper to recur to a more particular detail of 

 those parts which form the peculiarities of this plan. 



Construction of the Barrel. 



Construe- To those who are conversant with the principle of 

 tion of the -j^e construction of barrels for organs, chimes, and 



... l-l- r 



other automatical engines, that which is necessary for a 

 carpet draw-loom, will not appear very difficult ; but 

 for the use of mechanics who may wish to understand 

 the principle of this machine, it may perhaps be 

 proper to enter a little more into detail. The barrel 

 may be hollow, and built of thick and well sea- 

 soned plank, upon rings of cast iron, wedged, or 

 otherwise firmly fixed upon the axis, which may be 

 either of malleable or cast iron ; but the former is 

 certainly preferable in every respect. When the cover 

 is firmly joined by glue and countersunk screw-nails, 

 it is to be very truly and straightly turned ; and where 

 it can be conveniently done, this operation will be 

 better performed in the bushes or centres in which it 

 is afterwards to revolve than elsewhere. When this 

 has been done, it is only necessary to ascertain- the 

 places for the projecting pins ; and these will be much 

 firmer and less liable to accident, if screwed, than if 

 driven into the cover or circumference of the barrel. 

 In order to ascertain with precision the proper dia- 

 meter of the barrel, regard mu&t previously be paid, 



1st, To the extent or number of changes re- 

 quired in the pattern to be formed. This will be 

 easily found by referring to the design, as in mount- 

 ing the common carpet draw- loom ; for if the pat- 

 tern is the same, just as many sets of forks or pins 

 will be required for the power loom as there are bobs 

 or handles for the common loom. 



2dly, The range which is required to open the 

 each time to a sufficient dejith; and this may be 



barrel. 



found by attending to the principles upon which the 

 agency of the barrel upon the mail* of the harness 

 depends. Let us suppose, for example, that the 

 depth of shed formed by the harness requires that 

 the mails should be lifted three inches. Then as this 

 is to be effected by the deviation of the tail part from 

 the straight line, and that as one extremity of the 

 harness only is moveable without entering into all the 

 nicety of trigonometrical calculation, it may be as- 

 sumed that the lashes will descend to raise the mails 

 in the ratio of 2 to 1, or nearly so. If then the 

 barrel must move six inches at every shift, a very 

 large diameter indeed would be required for a very 

 moderate range of pattern ; and yet this, where it is 

 practicable, will be by far the easiest and cheapest 

 method. Taking, therefore, the shift of the barrel 

 at six inches each, a barrel six feet in diameter would 

 only work a pattern of about forty changes. But in 

 more extensive patterns, the barrel must be extend- 

 ed to a size, which would be totally impracticable. 

 Means must therefore be used to counteract this in- 

 con veniency, and fortunately these are simple and 

 obvious. It is obvious, that in the way in which the 

 lashes are fixed in the common carpet-loom, they 

 are well calculated for their purpose ; for a child will 

 find little inconvenience in pulling a handle six inches 

 down, but would find his strength totally inadequate 

 to raise a great number of weights suspended to the 

 harness, were the mechanical power against him. 

 Upon this obvious principle it is plain, that a few 

 small blocks placed above the barrel, to invert the 

 power and increase the range of the mails in rising, 

 will at once do away the inconvenience, and conse- 

 quently it will be easy to reduce the size of the bar* 

 rel, and increase the range of the weights in whatever 

 ratio may be found practically convenient. Where 

 the agency of water or steam is employed, the loss of 

 power can be an object of no consideration ; and no 

 judicious mechanist can be at a moment's loss to con- 

 struct them with any number of sheaves suited to his 

 purpose. It is simply the apparatus employed to 

 shorten the range of the weight which moves a com- 

 mon roasting jack. A few levers also might be very 

 easily so disposed as to produce exactly the very 

 same effect. For a cheap and simple practical subr 

 stitute, large glass beads, with a proper number of 

 smooth holes, and the cord rubbed with black lead, 

 would do very well. 



In the profile elevation, Fig. 7, not only the ge- 

 neral appearance of the loom will be exhibited in a 

 different point of view, but also some parts not 

 shewn in Fig. 6. and between both every thing of 

 consequence will be found. A recapitulation of the 

 whole reference letters will therefore be sufficient for 

 what appears in Fig. 6. and a short description for 

 those which do not. AA are two of the upright 

 posts extending from the floor to the roof, and firmly 

 secured to both. B is the post for the barrel, and 

 is here supposed to be fixed at the top to a cross 

 rail, nailed or screwed to the roof. C, D, and E do 

 not appear, being behind the post B. F is the end 

 of the axis of the barrel appearing through the up- 

 right post, and G the barrel itself, the rachet being 

 here placed to the left hand. H is the catch by 

 which the raghet is pulled. I the lower part of the 



