Patent GB-190406286-A (GB)
Title: Improvements in and relating to Power Looms for Weaving Embodying Pattern Controlled Shedding Motions
Inventor: SMITH HARRY WITTER
Filed: 1904-03-15
Granted: 1904-05-05
Abstract: 6286. Smith, H. W. March 15. Loom dobbies; weft-replenishing mechanism; stopmotions; shuttles.-Consists in the combination in a loom provided with a pattern-controlled shedding mechanism or dobby for weaving figured fabrics, of any or all of the following mechanisms : -weft-replenishing mechanism, electromagnetic or other detector mechanism for actuating the same on substantial exhaustion of the weft in the shuttle, and stop-motions acting on failure of weft, or breakage or undue slackening of a warp thread. In the dobby, Fig. 3, a pattern chain passes over a cylinder on a shaft a", which is rotated by worm, bevel, and spur gearing from the crank shaft, and the pattern chain causes hooked jacks a<4> to be engaged as required by knives a<3>, which are reciprocated in guides a<2> by links a<6> from vibrator arms a<5>, operated by suitable connection with a moving part of the loom. The jacks a' are connected by levers a<10> to pivoted levers A<2> from which the healds are operated. Any form of mechanism may be used for changing the shuttle, or the cop or bobbin in the shuttle. In the described embodiment of the invention, shuttlechanging mechanism substantially as described in Specification No. 5606, A.D. 1898, is employed, except that the link c<14> and the elbow-lever f <6>, described with reference to Fig. 2 in the said Specification, are connected by an intermediate link instead of being directly connected. When the weft in the shuttle is substantially exhausted, a metal ring b<4>, Fig. 6, completes an electrical connection between contacts b<5> connected to metal strips b<6> on the top of the shuttle, so that, when the shuttle enters one box, an electrical circuit is completed between two spring detectors b, b<1> projecting into the box to engage the strips b<6>. An electromagnet is energized, and its armature acts on a reciprocating actuator to place it in position to strike an arm on a shaft, and thus rock the shaft to actuate the shuttle-changing mechanism. In the electric circuit is a retarding-relay, comprising an electromagnet which is energized on the completion of the circuit through the detectors, and causes its armature to complete an auxiliary circuit through the first-mentioned electromagnet, after the detecting-circuit has been interrupted by the shuttle leaving the box. This circuit is finally broken by means of a switch actuated by a moving part of the shuttle-changing mechanism. The ordinary weft-fork and weft-hammer mechanism is used to stop the loom on failure of weft. The warp threads support drop devices k<10>, Fig. 4, which are slotted and guided by bars consisting of lower metal portions k<8>, and upper metal portions k<7> insulated therefrom. If a warp thread breaks or becomes slack, the corresponding device k<10> falls and electrically connects the parts k<7>, k<8>, thus completing an electric circuit. An electromagnet is energized, and causes its armature to withdraw a support from a dagger. The dagger falls and is struck by a bunter on the lay, so that it acts through suitable mechanism on the shipper handle to stop the loom. The circuit is broken when the shipper handle is moved by means of a switch one part of which is carried by the shipper handle and the other by the frame.