GB386174A - Improvements relating to driving mechanisms for loom dobbies - Google Patents

Abstract

386,174. Loom dobbies. SOC. LYONNAISE DES MACHINES TEXTILES, and MILLIAT, L., 14, Rue Elie-Paris, Lyons, France. March 29, 1932, No. 9073. [Class 142 (i).] In order that the last weft tread may be found easily, mechanically-operated means are provided for moving the dobby backwards at a reduced speed, the main shaft then being held stationary. In the form shown in Fig. 2, the dobby is driven reversely by a shaft 28 from a motor 14 through gearing 15 .. 25. The wheel 25 is splined on the shaft 28 and is integral with a toothed wheel 26 carrying a single claw tooth 27 for engaging a similar tooth 32 on the loom crank or other shaft 33. When the gears 25, 26 are moved to the left by means of a rod 31, the shafts 33, 28 are driven together by engagement of the pinion 20 with the wheel 26, the gears 24, 25 being disengaged. A driving clutch 18 operated by a lever 19 allows the loom as a whole or the dobby in reverse to be driven as desired. In the form shown in Fig. 1, the dobby is driven by a chain wheel 5 on a plate 6 loose on a sleeve 2<1> which is fixed to the driving pulley 1 loose on the crank shaft 3. The crank shaft carries a plate 7 provided with a planet wheel 8 in mesh with a pinion on the sleeve 21 and an internal gear on the plate 6. Normally, the plates 6, 7 are locked by a spring-pressed pin 9 carried by the plate 7 engaging in a hole 10 in the plate 6. When the loom is stopped, the dobby may be driven backwards by withdrawing the pin 9 by a knob 12 and moving the belt from the loose pulley 4 on to the driving pulley 1. The shaft 3 being held by the brake prevents rotation of the plate 7 carrying the planet wheel, so that the chain wheel 5 is driven backwards at reduced speed. The pin 9 is held retracted against the action of its spring by a projection 13. On rotating the knob through a quarter of a turn, the projection is free to move in a slot to allow the pin to re-engage with the plate after an integral number of revolutions of the chain wheel. In a modified arrangement, the crank shaft is driven by a pulley fast on that shaft, while the loose pulley carries a sleeve provided with a pinion in mesh with planet wheels in gear with an internal gear on the chain wheel. The planet wheels are carried by a disc normally loose on the shaft, and run idly. When the dobby is to be driven backwards at reduced speed, a spring-controlled key operated by a lever is moved to lock the disc and disengage the driving shaft from the chain wheel. On the completion of a revolution, the key moves under the influence of its spring into normal position for driving the chain wheel.