Mechanism to control the oscillations of the heald frame connecting rods in a rotary dobby.

摘要

Mechanism to control the oscillations of connecting rods (2) operating the heald frames (1) in a rotary dobby, of the type wherein, for each frame (1) and connecting rod (2): said rod (2) is mounted on a drive shaft (3) by way of an eccentric (4) interposed between said shaft (3) and the connecting rod small end (17); said eccentric (4) can be controlled for rotation, alternatively with the connecting rod (2) or with the shaft (3), means of a radial key (14); mechanical means are provided to shift said key (14) in the outer position of engagement of the connecting rod small end (17); spring means (18) are provided to return said key in the inner position of engagement of the shaft (3); and electromagnetic means (19,20) are provided to hold, when energized, said key (14) in the outer position of engagement of the connecting rod small end (17). Said electroma­gnetic means consist of a pair of magnets (19,20), positioned opposite externally to the connecting rod small end (17) and apt to be alternatively energized, a permanent magnet (21) being associated to one of said magnets, said permanent magnet (21) having a field equal and opposite in sign to that produced by said magnet (20) when it is energized.