To obtain the subject controlling mechanism capable of adjusting the gap of yarn guides to be attached to the front and rear ground guide bars with a simple operation and improving the workability by using a connection means interlocked with a supporting shaft and enabling the interlocking of supporting shafts with each other to enable the adjustment of the gap between the yarn guides.

This mechanism is provided with a pair of supporting shafts 12, 13 extending parallel to the longitudinal direction of a knitting machine and rotatably pivoted on a machine frame 14 and with holding members 10-1 to (10-n), 11-1 to (11-n) holding ground guide bars 1-4 and attached to the supporting shafts 12, 13 interposing gaps between the bars. The supporting shafts 12, 13 are interlocked with each other in such a manner as to enable the adjustment of the gap between the yarn guides 1a-4a to be attached to the front ground guide bars 1, 2 and the rear ground guide bars 3, 4 held by the respective holding members 10-1 to (10-n) and 11-1 to (11-n). The supporting shafts 12, 13 are interlocked with a connection means 15 consisting of a link mechanism or a connection gear mechanism.