Page:The New International Encyclopædia 1st ed. v. 12.djvu/507

* LOOIKE. 449 LOOM. the cards for tlie needles controlling those warp- threads which are not to be raised. After the chain of cards is placed on the card-cjlintler and the pattern-card, which just covers one face of the cylinder, is brought in contact with the needles projecting through the needle-board, those needles which are opposite the holes cut in the card pass through and enter the pcrfnratidMs in the cylinder as if no card were there, while wherever there was no hole cut the neeiUe is forced back, and with it the top of the hook which it governs, to a position l! l! f(T A'!| Fir. 4. JACQDARD MACHINE. SO that the griffe, I, 1, as it is raised, 1', 1', pas.ses the hooks and the knives only engage and lift the hooks which have not been pushed back by the card; and everj- hook in the machine which has not been pressed back is raised by the griflfe and with it the harness attached to it and the warp-threads which it controls. Thus it is obvious that any desired interlacing of the tlireads in the fabric can be obtained by the way in which the pattern-cards are perforated, each separate card regulating the warp-threads for the entrance of one thread of filling, and there being as many cards necessary as there are fill- ing-threads in one repeat of the pattern ; some very elaborate designs have required the use of 20.000 to .30,000 cards for a single design. There have been many different looms pro- duced to weave special fabrics, all embodying the three principal movements necessary to the process of weaving. Broadly speaking, looms are classed as narrow looms and hroad looms, the former being built to produce fabrics up to forty-eight inches in width, the latter up to one hundred or more inches in width. There are special looms for carpets and rugs, and looms specially arranged for weaving seamless bags and tubing, such as lawn-hose or lire-hose is made from. There are narroii:-fuhric lodtn.i arranged to weave tapes and ribbons; one loom-frame supports the harness and mechanism for con- trolling them, and a number of separate warps are arranged side by side — sometimes as many as forty — and woven simultaneously. The special feature of looms of this description is that the shuttles are passed through the sheds by a posi- tive motion at a iniiform velocity instead of being driven through with picker-sticks; or the filling may be carried through the shed with a needle attachment instead of a shuttle. In the sicivel-loom, by the introduction of a special filling interlacing with a small section of the warp instead of extending from selvedge to selvedge, as the regular filling does, the weaver is enabled to produce special striped or figured effects ; the attachment for manipulat- ing this special filling-thread is so arranged that certain filling-carrying devices may be brought into the line of the open shed when the special filling is to be introduced and the shuttle carrying the regular filling stopped until the special filling is inserted, when the attachment is removed from the shed automatically, and the- regular filling for the groundwork of the fabric is again passed through its shed. There are three appliances of importance which, while not parts of the loom proi)er. are to be found in use on all looms, whether hand or power — the loom-harness, the loom-rccd, and the shuttle. The loom -harness may be a set of two parallel rods somewhat longer than the fabric is to be woven in width, on which are arranged twine hcalds or hcddles, with eyes at the centre for the warp-thread; or a skeleton frame on which are placed wire heddles; or the Jacquard harness, which has already been de- scribed. The loom-reed, though originally con- structed from pieces of reed, is a series of thin pieces of flattened wire inserted at right angles in two parallel strijis of wood which are from three to five inches apart, according to the fabrics on which they are to be used ; the wires are spaced equally over the whole length of the reed, which is usually longer than the loom harness, and the reed is nearly always designated by the number of spaces to one inch. The loom- shuttle is of hard wood, generally in the shape of a prism one to two inches S(|uare and from a three to five inches apart, according to the fabric to be produced, and reduced to a point at each end, tipjicd with metal; this prism is hol- lowed out not unlike a small boat, and the fill- ing, usually arranged on a tube or bobbin, is secured on a spindle in the cavity in such a way that the filling-thread may be pulled off from the small end of the bobbin through the eye of the shuttle. BiRi.iOGRAPHT. Consult:'' Posselt. Textile Machinery Relating to Weaiittg (Philadelphia, 1901) ; Bvrne. Progress of Invention in the yine- teenth Centura (Xcw York, 1000): Ashenhurst, Wearing and Designing for Textile Fabrics (Lon- don, 1887) : Brown, Practical Treatise nf the Construction of the Power Loom (Dundee,