Patent GB-872570-A (GB)
Title: Improvements in or relating to ribbon looms
IPC: D03D35/00
Filed: 1957-09-16
Abstract: 872,570. Ribbon looms; automatic spool changing; weft stop motion. REDAELLI, E. Sept. 16, 1957, No. 29085/57. Class 142(2) A ribbon loom having a shuttle which does not partake of the beat-up movement of the reed is provided with mechanism for detecting depletion of the weft spool and automatically changing the spool, and with mechanism for stopping the loom if the weft breaks. Propelling shuttle. The shuttle 33, Fig. 3, is moved from one to the other of stationary lands 34, 35 by means of a shaft 25 carrying sectors 30, 31 which can engage grooves 32, Fig. 5, in the underside of the shuttle. The shaft 25 is moved endwise by a lever 21, Fig. 1, actuated by a cam follower 20 running in a grooved cam. At the beginning of the movement from the land 35, the sector 31 is in engagement with the shuttle and moves it until its leading end emerges from the shed; the shaft 25 is then given a quarter turn to withdraw the sector 31 from the trailing end of the shuttle and engage the sector 30 with the leading end; continued endwise movement of the shaft 25 draws the shuttle into the land 34. Spool feeler. The spool, Fig. 4, consists of a telescopic body 45, 46 normally kept in the contracted condition by the windings of weft yarn on it, whereby a vertically-reciprocating fork 68, Fig. 3, can pass freely over the spindle 47. When only a few turns of weft remain, the spool extends to block the path of the fork 68 as shown in Fig. 4. The fork 68 is housed in a sheath 66 Fig. 3, which is pushed upwards, when the shuttle is stationary on the land 35, by a cam 64, Fig. 1, acting through a pushrod 65. If movement of the fork is impeded by a depleted spool, the sheath continues to move and a pawl 70 snaps into a notch in the fork when it comes into register with a notch 72 in the sheath, thereby holding the fork retracted within the sheath to initiate spool changing as described below. Spool changing. As the shuttle moves from the land 35 to the land 34, a rod 61, Fig. 3, moves in the same direction. A lever 63, pivoted on the rod, can normally pass through coinciding notches 73 in the sheath 66 and fork 68, but when the fork is in the retracted position it blocks the notch, thereby causing the other end of the lever 63 to move a block 52 endwise of a shaft 53. This movement brings an arm 54 into engagement with a forked lug 56 carried by the reed support 12. During the forward movement of the reed, the lug rides along the arm 54 and, owing to the downward inclination of the arm, raises it, causing an arm 51 to descend; a link 50 rocks a spool feeder 38 (pivoted at 39) downwards to deposit a replacement spool 40 in the shuttle. A fresh spool is then placed in the feeder 38 by the weaver in readiness for the next operation. Shuttle. In the form shown in Fig. 5, the weft 121 is tensioned by running between a pivoted semicircular pallet 106 and the upper surface of an arm 110 loaded by a spring 113 adjustable by a screw 116; pins 108, 118 prevent the weft from escaping. During spool changing, a roller 122 on the feeder depresses the arm 110 to allow the weft from the fresh spool to snap under the pallet 106. The weft passes through a slot 43 in the feeder and is retained in the slot by a nose 125 on the arm 123 until the arm is swung by the roller 122 encountering the arm 110. Weft stop motion. As the shuttle arrives in the land 35, the weft extending from the fell to the shuttle, Fig. 3, passes between the prongs of a fork 80 which is slidable and rotatable in a mounting 79. When the shuttle has come to rest, a rod 86 (operated by the cam 64, Fig. 1) descends, thereby allowing the fork 80 to turn under the weight of lugs 82, 83 projecting from it. If the weft is intact, turning of the fork is limited by its prongs coming into contact with the weft, but if the weft is broken the lug 82 falls into the path of a striker 85 on the reed support 12; when the reed moves back after beat-up, the fork 80 is pushed rearwards, against the action of a spring 84, to stop the loom. Beat-up motion. The reed support 12, Fig. 1, is carried by links 9 and operated by a circular cam groove 6 so disposed that its circumference intersects its axis of rotation 3, whereby the reed dwells at its rearmost position whilst the shuttle traverses the shed.