Patent GB-372788-A (GB)
Title: Improvements in change box motions of looms for weaving
IPC: D03D43/00
Filed: 1931-01-07
Abstract: 372,788. Loom change-box motions. MITCHELL, J. G., Annieslea, Milliken Park, Kilbarchan, Renfrewshire. Jan. 7, 1931, No. 37477/30. [Class 142 (iii).] Pattern mechanism for controlling the movement of the shuttle boxes includes a card cylinder which is oscillated, so as to present in turn an even number of cards for the introduction into the design of a series of picks of each particular weft, or is rotated unidirectionally under control of pick counting and weft change mechanism. The additional control means are so arranged that, when a predetermined number of picks have been inserted, the pick counting mechanism is returned to a starting position, which is determined automatically by the number of picks subsequently required, and the weft-change mechanism is operated to bring the successive set of cards into operative position. The apparatus is driven from the loom through a lever a, Figs. 3 and 4, which performs one oscillation for every pick and gives a rocking movement to a shaft b through a motionmultiplying train comprising members a<3>, d, c, e, f. The pick-counting mechanism comprises a ratchet wheel k, Fig. 1, a cam disc m, and a pulley zl, all mounted on a shaft n, the ratchet k being driven by means of a pawl l and connections j, h, g from the oscillating shaft b, and held against backward movement. by a stop pawl o. The cam disc m is provided with a slot c<1> which is positioned beneath a roller a<1> on a lever b<1>, after insertion of the requisite number of picks, the resultant downward movement of the roller serving to tilt a pivotally mounted bracket d<1> and bring the pawl c<2>, of a reciprocating pawl bar f carried thereby, into engagement with a ratchet g<1> on the weft change shaft v<2>. With the movement of the bracket d<1> a sliding clutch l<1> is brought into engagement with a sleeve s which is loosely mounted on the shaft v<2> and, during the subsequent rotation of the latter, the card cylinder v receives an angular displacement, which is double that of the shaft v<2>, to bring a fresh set of cards into operative posftion. When two cards are used for inserting a series of picks of the same kind of weft, the card cylinder is oscillated by means of pawls u provided on a tilting lever t which is reciprocated by means of connectors t<1>, e<1> from the lever e and is oscillated to bring either of the pawls u into engagement with pins v on the sleeve s. The lever t is tilted by means of a face cam w on a shaft m<2> which is rotated through 90‹ by means of a ratchet wheel n<2> driven by a pawl s<4> and lever connections r3, q<2> from the shaft b. After a colour change has taken place a depending leg r<2> on a lever r<1>, which is pivoted at s<1> and t<4>, is engaged by a roller q<1> on the disc m and caused to register with a slot u<1>, thereby permitting a lever r<1> to rock under spring action and engage a member v<3> on a lever v<1> w<1>. Movement of the latter brings the arm w<1> into contact with a lever x<1> to raise pawls l and o and allow the cam disc m to rotate to starting position under the influence of a weight y<1> which is connected to pulley z<1>. During the rotation of the disc a cable a<2> raises a slide b<2> until one of a number of pins c<3>, d<3>, e<3> of different lengths and adjustably mounted thereon, is engaged by a lever f<2> which is controlled by an asymmetrical cam g<2> on the shaft v<2>, the engagement of a pin with the lever f<2> serving to rock a lever l<2> and lower the lever x<1> thereby permitting the pawls l, o to re-engage the ratchet k. The amount of movement imparted to the face cam w may be varied by employing additional ratchets o<2>, p<2> operated by pawls s<4> which are driven through differently dimensioned linkages. Further, a drum u<2> on the shaft v<2> may be provided with pins t<6>, t<11>, t<12> adapted to engage levers t<5> and disengage the pawls s<4> thereby stopping the movement of the cam w and causi.ng a series of cards to be presented in turn to the box levers. Broken designs in a variety of colours can be woven by omitting one or more of the pins on the drum u<2>.