CLOTH MANUFACTURE. 



691 



Cloth quired. In the Figure, tlie motion required being uni- 

 Manutac- f nrm> the divisions are equal. The divisions on the radii 

 yj 1 "'^^ being joined by oblique lines, the wheel will be comple- 

 ted, and the more numerous the radii are, the nearer will 

 be the approximation to geometrical accuracy. Thus, 

 in the Figure, the whole range of motion is the excess of 

 the line from the centre to c, above that from the centre 

 to b, and, this being equally divided, the motion must be 

 uniform. Upon this principle, depends the construction 

 of all traverse wheels for the production of motion. The 

 traverse, therefore, at A, being constructed on thi 

 principle, it is only necessary further to observe, that if 

 it is made in two separate pieces, one of which would 

 move the treddle 1, and the other the treddle 2, the 

 warp will be regularly and alternately opened by the suc- 

 cessive action of these two parts ; or if the centre of mo- 

 tion, where the warp is closed, be made at '2, both open- 

 ings or sheds would be formed by half a revolution of 

 the shaft, and only one treddle would be necessary, 

 for the other would form itself simply, by suspending a 

 weight from the heddle. In the latter case, it would be 

 better to form the range upon the semicircle than the 

 quadrant, which may easily be done. 



The second necessary motion is that of the Ly, which 

 is done by a wheel similar to the former. If the tra- 

 verse for the heddles operates twice in one revolution of 

 the axis, that of the lay must reciprocate four times ; but 

 Fi{. 1. this is perfectly unnecessary in either. Suppose the tra- 

 verse at A, Fig. 1, to operate successively on two alter- 

 nate treddles for the fast motion, and twice on the same 

 treddle for the second, then the effect required will be 

 produced, and this is the usual way. In this plan of 

 power looms, the lay is only brought back by the tra- 

 verse, and returns by the operation of a weight at D. 

 The shuttle motion may be given, by attaching the dri- 

 ver cords to two treddles, struck alternately by wipert 

 fixed on the axis ; or it may be communicated as in the 

 crank loom, Fi-,*. 2, which we shall now describe. 



The crank loom is set in motion by the operation of 

 two transverse shafts, and operates entirely without tred- 

 dlei of any kind. The first shaft, the end of which 

 appears at A, is placed perpendicularly under the hed- 

 dles, and gives motion to them by a double or alter- 

 nate crank, the Figure of which is shown by Figure 

 7. As one revolution of this shaft consequently openi 

 the heddles twice, it ii necessary that the lay fhould ope- 

 rate twice in the same space of time. This, therefore, is 

 effected by a separate shaft with two direct cranks, and 

 which revolves twice in the same space of time that the 

 former undergoes one revolution. The particular formi 

 of the crank, and the wheels which connect them, are so 

 clearly pointed out in the Figure, that it teems unneces- 

 sary to go further into detail in the description of this 

 tig. 8. machine, than to explain the other Figure 8, which 

 operates on the cords which gave motion to the shut- 

 t! . This double or reciprocating lever is fixed to 

 vibrate upon its cei tre under the web, and rather in front 

 of the heddles. The cross shafts of the lever at A and 

 B, are alternately struck by pi- jectm^ pieces of iron fix- 

 ed on the front shaft, and thus the motion is ^iven al- 

 ternately, According to the end of the lever which is 

 struck. This may be equally well applied, and frequent- 

 ly it s~, t'. the :p'-r l<,um. Fig. 1 ; for both the time and 

 quantum of moti.m in i-ach machine 13 precisely the tame. 

 A th'rd Kind of power loom, invrii'rd by Mi Jolin on, 

 wag introduced some time ago by Mr Shirreff of Glas- 

 gow, v. luc , fron, its form, it called th.- vertical loom, and 

 which POSMMCI ut utility and convenience, some 



essential advnta^ti over either of the above. 



Crank 

 loom. 

 PUT* 

 CXCV. 

 Fig. 2. 



Kg. 7. 



This loom is represented in Piates CXCV I. and 

 CXCVII., and its construction will be understood from 

 the following description. 



The vertical pos.tion of the web requires that the 

 slaise, or lay, (i. e. the frame which carries the reed and 

 shut'le boxes,) should have a vertical reciprocating mo- 

 tion, audit accordingly strikes the reed upw-rds against 

 the cloth in drawing up the woof. The yarn beam is 

 placed below, and the yarn passes from it first up through 

 the heddles, or harness, and then through the reed. It 

 passes thence to the temples, and upwards to a roller, 

 which serves to direct its motion a little backwards to 

 the cloth-beam, upon which it is wound up by the ma- 

 chine, in proportion as the cloth is formed. 



It is obvious, that the healds must act in this loom ho. 

 rizontally, which is done in a very simple manner, whilst 

 the pecking motion (;. e. the motion of the shuttle) is 

 produced by means of a very natural contrivance, imita- 

 ting with great precision the motion of the weaver when 

 working with his fly shuttle. In case any thing occurs 

 to interrupt the motion of the shuttle, that very interrup- 

 tion causes the loom to stop, and prevents all further harm 

 to the yarn. 



From this general description of the loom, it is hoped 

 that, by the help of a short reference, the Figures will 

 easily convey a distinct notion of its general construction. 



Plate CXCV1. is a profileelevation of a cast-iron frame 

 containing two of the vertical looms. 



Plate CXCVII. is a front elevation of one of the 

 looms. 



The same letter refers to the same part, when they 

 occur, in both Figures. 



The pu'.ly A A receives its motion by a belt from the 

 mill work, and it moves the lo<;m when a bayonet B 

 connects it with the first axle C c. 



On the axle C c are two cranks, by means of which 

 there is a vertical reciprocating motion communicated 

 to the slaise DEFG, Plate CXCVII. 



HI is the reed, and DH, DE, the shuttle boxes. 



The shise is guided in its vertical reciprocating mo 

 tion by the side posts of the framing, and strikes the 

 reed upwards against the cloth in driving up the woof. 



By means of the wheels K, L, motion is communica- 

 ted from the first axle C c to the second axle M m, 

 which, by cranks and other contrivances, produces a 

 horizontal motion in the healds NO, and it does thig 

 at the same time that it produces the pecking motion, 

 (i.e. the motion which drives the shuttle,) by means of 

 the alternate motion of the email vertical axle PR, and 

 its projecting arm OR, which arm gives motion to a 

 fly shuttle by thongs, &c. 



ST is the yarn-beam, from which the warp passes 

 upwards through the reed, and the cloth, guided by a 

 roller, passes backwards, and is wound up in proportion 

 as it is formed up:>[> t!u cloth-beam V W. This is done 

 by means of a ratchet wheeel X worked by the motion of 

 the slaise, but so contrived as not to take off the cloth 

 unless it be suiBciently thick. 



Z, a small balance- wheel for regulating the motion. 



The following is a inscription of a loom invented by 

 the author of this article, with a view to remedy some of 

 the inconveniences whicn appeared to him to attach most 

 strongly t.> the vertical .corns of the preceding construe- 

 tion, which he had examined. A model was constructed 

 under his inspection, sufficient to weave a narrow muslin 

 web, which wan tried as an experiment, and the pressure 

 of attention attending anoth.-r important mechanical ope.- 

 ratMit in which he was, then engaged, prevented him from 

 bestowing upon it all the attention which might have 



Cloth 

 Manufac- 

 ture. 



Johnson's 

 vert cal 

 loom 

 PLATCB 



CXLVI. 



and 

 CXCVII. 



CXCVI. 



PLITE 

 CXCVII. 



Duncan's 

 new vibra- 

 ting loom. 



