SE437169B - DEVICE FOR FEEDING THE TOWING STRAIGHT IN THE LUMBER - Google Patents

Description

7904200-8 Fig. 2 is an enlarged plan view of a speed changing mechanism.

Referring to Fig. 1, there is shown fragmentarily and schematically a needle loom, generally drawn at 10, for weaving a fabric 11 of a weft thread 12 and warp threads 13.

The needle web 10 essentially comprises a plurality of shafts 14 for scaling by selectively raising and lowering the warp threads 13, a weft carrier 15 for insertion of the weft threads 12 through the warp grounds, a tongue needle 16 for reciprocating movement in the warp direction along one of the longitudinal edges of the fabric 11. for catching and tying the weft thread 12 in the warp bead, for forming a city edge along one of the longitudinal edges of the fabric and a ride 18 for winding the weft thread 12 in the warp bead against the edge of the fabric 11. Along the side of the warp threads 13, the weft thread 12 extends from a cross spool, not shown, of known construction, to the fabric 11 via a pair of feed rollers 19, 20, a tension control device 21 and an eye 22 on the weft carrier 15.

The voltage control device 21 comprises a pair of opposite, resilient angular parts 23, 24, a pair of inlet and outlet guides 25, 26 and an intermediate guide 27. Each resilient part 23 (24) is fixed at its helical end to a stationary pin 28 ( 29), and has an eye 30 (31) at its free end. In the voltage control device 21, the weft wire 12 travels via the inlet guide 25, the intermediate guide 27, the eyes 30, 31 and the outlet guide 26.

As the weft carrier 15 reciprocates in and out of the successive warp grounds for insertion of the weft yarn 12 therethrough, the weft yarn 12 is pulled out intermittently, whereby the weft yarn 12 alternately becomes taut and loose. Instantly, this voltage change in turn causes the opposite resilient members 23, 24 to bend and return, so that their respective eyes 31, 30 move toward and away from each other depending on the magnitude of the resulting tension of the weft threads 12. Thus, the tension of the weft trees is controlled so that it remains constant through spring action. 17 denotes the path which 22 on the weft carrier 15 follows when the weft carrier runs back and forth.

In order to minimize the magnitude of the voltage change to be corrected by the tension control device 21, the weft threads 12 are fed through the feed rollers 19, 20 at variable speed depending on the amount of weft thread 12 pulled out by the weft carrier 15, the feed rollers 19, 20 are arranged upstream of the voltage control device 21.

Correct speed changes of the feed rollers 19, 20 can be obtained by a speed changing mechanism, as shown in Fig. 1, generally indicated by 32. As best seen in Fig. 2, the mechanism 32 essentially comprises a gear transmission comprising a pair of spaced first and second sun wheels 33, 34 and a planet wheel 35, arranged between the two sun wheels 33, 34, and mating therewith, the first sun wheel 33 being eccentrically arranged on a drive shaft 36. The planet wheel 35 is arranged on a pair of first and second pivot arms 37, 38, so that it rolls on both the first and the second sun gear 33, 34 in continuous engagement therewith as these gears 33, 34, 35 rotate. Assuming that the first sun gear 33 undergoes a complete rotation counterclockwise, see Fig. 2, at a constant angular velocity, and thus with a variable peripheral speed, the planet wheel 35 rotates clockwise with a variable speed and thus the second sun wheel 34 rotates counterclockwise with a variable speed. The endless belt 39 runs around a pair of discs 40, 41, concentrically arranged relative to the second sun gear 34 and one of the feed rollers 19, 20 and respectively, for rotating the feed rollers 19, 20 at variable speed - alternating at high and low speed . The feed roller 20 is a clamping roller.

This change in speed of the feed rollers 19, 20 is synchronized with the movement of the weft carrier, i.e. these feed rollers 19, 20 are rotated at high speed when the weft carrier 15 moves in the warp ground and at a lower speed, while the weft carrier 15 returns from the warp ground.

A single specific embodiment of the invention has been described above, but the invention is not limited to this embodiment alone, since a large number of changes and modifications may be made therein within the scope of the appended claims.

POGR Qâfâmi?

Claims (2)

7904200-8 '4 Patent claims 1. l. Device for feeding a weft thread (12) to a weft carrier (15) in a needle loom (10). The weft carrier is movable back and forth over successive warping grounds to insert the weft thread (12) therein. The device includes a pair of feed rollers (19,20) for feeding the weft thread from a cross spool to the weft carrier at varying speeds. Resilient means (23.2U) are provided for correcting the tension of the weft trees during pulling. The device is characterized in that one (19) of the two feed rollers is drivable by means of a driven gear (BH), which is driven at varying speeds via an intermediate gear (35) from a driving gear (33), which is rotatable. on an eccentric shaft (36), and that the intermediate gear (35) is mounted at one end of two pivot arms (37,58), at the other ends of which the driving and the driven gear (33,3U) are centrally mounted. Device according to claim 1, characterized in that the resilient means comprise two angularly resilient spring elements (23,2Ä) arranged, one end of which is attached to each fixed pin (28,29) and whose other ends are provided with a separate loop (30.3 l), which guides the passing weft trees (12). '