. A dictionary of arts, manufactures and mines : containing a clear exposition of their principles and practice. or the jacks ; and a hole beingdrilled through each jack and each comb, one polished wire put through, serves as a com-mon centre for the whole. The jack sinkers being only used for every alternate or second needle, in order tocomplete this part of the apparatus, a second set of sinkers is employed. These are, inform and shape, every way the same as the jack sinkers, but they are jointed at the topinto pieces of tin, all of which are screwed to the sinker bar h, fig. 552; and thus a
. A dictionary of arts, manufactures and mines : containing a clear exposition of their principles and practice. or the jacks ; and a hole beingdrilled through each jack and each comb, one polished wire put through, serves as a com-mon centre for the whole. The jack sinkers being only used for every alternate or second needle, in order tocomplete this part of the apparatus, a second set of sinkers is employed. These are, inform and shape, every way the same as the jack sinkers, but they are jointed at the topinto pieces of tin, all of which are screwed to the sinker bar h, fig. 552; and thus asinker of each kind descends between the needles alternately. By these sinkers theloops are formed upon all the needles, and the reason of two sets different in operationbeing employed, will be assigned in describing the mode of working the frame. Thepresser of the operation, of which something has already been said, appears at f; andof the two arms which support and give motion to it, one appears very plainly at e, itscentre of motion being at c. The circular bend given to these arms, besides having an 558. 554 42 ornamental effect, is very useful,in order to prevent any part frominterfering with the other partswhich are behind, by elevatingthem entirely above them. Theextremities of these arms at thetermination of the bends behind,are connected by a cross bar,which has also a circular bendin the middle, projecting down-wards, for a reason similar to thatalready assigned. This bend isconcealed in^g. 552, but visiblein the front elevation, fig. the middle of the bend,the presser is connected with themiddle treadle by a dependingwire appearing at M,fig. 552, andthus, by the pressure of thattreadle, the presser is forced downto close the barbs of the re-ascent of the presser issometimes effected by means ofa counterpoising weight passingover a pulley behind ; and some-times by the reaction of a woodenspring, formed of a strong hooplike that represented at k. T
Size: 1423px × 1755px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1840, booksubje, booksubjecttechnology
